electlgy

Solar Power Bank Really Works

2021-06-14T15:13:00.007+05:30

Solar Power Bank

Solar power bank

Introduction

Power banks have become a very important thing in daily life. The benefits of a power bank can be understood only when the power supply is cut off in some way or when we go somewhere, in other words it is a very important thing when traveling.

Solar Power Bank Really Works

But in the present age we are so busy with laptops or mobiles that there is no time to recharge them. And if there is a power cut at that time, we get lost of mind.

Well, if our power bank had been recharged before it was charging. Even possible, yes it would be possible if we had a solar panel in our power bank.If we had solar panels installed in our power bank, we would just put the power bank in the sun and the power bank would be automatically charged.

Yes, a question arises here. Can everyone really charge the solar panel the power bank?

To answer this question we need to know how solar panels work, Types of solar panels how to install solar panels so that solar panels can give their maximum output, irradiation, weather wise output,loss with prevention and some mathematical explanations are required. These will be described one by one below.

Working of solar panels

A solar panel and diode are always the same but solar panels have some differences. At first solar panel made by semiconductor material like germanium silicon.

We know that any passive element contains N-type and P-type material, since a semiconductor device is made of germanium or silicon. Some impurities are mixed in this germanium or silicon semiconductor conductor material.

N - type material impurities called Pentavalent impurities and P-type materials called trivalent impurity. This impurity method is called doping. The impurities in N-type material use phosphorus and P-type material use impurity is boron.

Due to this type of impurity, the number of holes in n-type material increases and positively charged electrons move in p-type metal.A positively charged electron cannot be neutralized with a negative charge because a junction or depletion layer is formed.

We know that the light source is the current of the photon particle and another thing is known that the semiconductor material reaches the conduction band when there is any hit or biasing from outside.So the radiation of the sun on the solar panel starts pushing the posts in the n-type metrorail towards the positive electrons and current can flow through the circuit.

Type of solar panels

Solar panels are 3 types

*Nowadays Monocrystalline cells are very popular for this type of element because of their efficiency and economical view.

Theory

What do you think I need to know? This is because you need to know all the information about the quality of a solar panel power bank when you use it so that you can choose its quality.

Usually when solar panels are installed at home or in the office or anywhere. Then the solar technician has three things that are important: radiation, tilt angle, orientation angle.

By measuring these three things, they can understand that if the solar panel is set in exactly the right place, then the solar panel will be able to give data the highest efficiency output. If a house is facing south, then solar panels should be installed in a place where the sun can cover the solar panels all the time of the day.

If that is not the case then the problem is that we get maximum sunlight from 6am to 3 pm (approx)If this 9 hour solar panel does not get sun then you will lose a few hours. The battery will not be fully charged at that time.

For Generate Maximum Efficiency what is the best position of Solar Power Bank

Now the question is how do we find out these three things Tilt Angle, Orientation and Irradiation. That being said you can say someone is a solar technician or. Or they can try it out themselves. And some mobile apps will solve this problem very easily if their use is known. Mobile apps can tell you how much your solar panel is losing.

Tilt angle

If a solar panel is placed at the point where the perpendicular of a straight line is formed, the tilt angle is what the solar panel makes above the perpendicular.

Tilt angle

Orientation angle

When a solar panel can rotate 360 degrees according to the circumference of a sphere, what is the orientation angle according to the circumference of the sphere of that solar panel.

Orientation

Irradiation

The amount of sunlight that falls in every 1 square meter area is called irradiation.

Output from various Experiments with solar cells and solar power bank

If we test 50 watt solar panels the maximum open circuit voltage output is 21.10 v at full sunlight and the open circuit current is 1.92. A . Here we find the maximum power output open circuit is by simple formula P=V×I is near about 40.56 Watts.

Here almost 18.88% power loss due to not properly installation. This cell's power rating is huge because it does not use mobile phones or power banks . The power bank's maximum output voltage is 5.2 volt and maximum output current is 2 A so output power is almost 10.3 watts . Maintain this maximum output of 10000 mah charging time approx 5.2 hours .

That is why it is necessary to measure the tilt angle, orientation angle and irradiation. If these three things can be measured properly, then the solar panel will be able to turn on its maximum output. And to charge the power bank, it will take the time written in the calculation.

Weather wise output from Solar panel in Power Bank

Monocrystalline solar panel fluctuation of output is minimum . However, we have tested that the maximum output open circuit voltage does not fluctuate at 8% -10%.

Our test results are at maximum full measured maximum output open circuit voltage is 5.03 volt and current is 2.1 A so power is 10.56 watt . Total charging time is 4.7 hours.When the sky is full of clouds the Maximum open circuit voltage is 4.33 volt and current is 1.7 amp the output power is 7.36 watt. Total charging time is 5.8 hours when 10000 mah power bank is used .

Here we can clearly declare that minimum charging time is 4.7 hours and maximum 5.8 hours is 10,000 mah power bank use.

If you maintain the proper tilt angle, orientation angle and irradiation.

If use Solar Power bank your can save your energy which can use for charging. If 10,000 mah power bank use then you can save 50wh energy consumption.

Solar tracking device

Solar Tracking Device

Alternatively if you not want adjust proper tilt angle , orientation angle and irradiation. the you can buy solar tracking device . This device can helps to generate electricity from sun is maximum . This is helps to automatic adjust position change according sun position. Other words says this is Robot which can help you for charge maximum power from sun light.

Which is available is any online marketing platform. And it can available only 600-1000.

Conclusion

Green power is one of the main sources of energy for the future. And which we should use from now on. We should try to save as much electricity as possible. Different engineers and scientists from different countries are working to use this solar energy in different ways.

Can a DC Generator utilise Wastage Energy in a Traction System

2021-06-07T01:14:00.008+05:30

Can a DC Generator utilise Wastage Energy in a Traction System

Introduction

DC Generator most of the time motors used in traction systems or e cars . There are some reasons for this, the main part is loss.

e-cars or traction systems powered battery or solar panels. If the amount of loss is higher in all these cases then the overall efficiency of the total system will decrease.

So we will discuss some things in this topic to reduce the losses in the whole system to make the efficiency of e-car or traction system more than normal. example some kinetic energy is lost while driving which we cannot utilize.

If we can recharge the battery by generating a DC supply through that kinetic energy DC generator, then the mileage of that car will be much higher than normal.

we must first say that when the car starts to move, sometimes there is acceleration, most of the time it is retardation.In other words, if we look at our traction carve.

we will understand that first the acceleration, then the speed of acceleration remains normal for a long time, then it goes to retardation.

In other words, if we look at our traction carve, we will understand that first the acceleration.Then the speed of acceleration remains normal for a long time, then it goes to retardation.we can try to utilise the power of retardation .

DC Generator

We also know that the DC generator works on Faraday's electromagnetic induction DC generator to generate electricity by helping the commutator and brush.

Mechanical power drives the DC generator shaft to generate electricity e in the output terminal. We do not give a detailed explanation of the DC generator.

DC generators are classified by many types. Not all of these traction systems work. Only flat compound DC Generator

Traction system

The traction system is the motor that can move a system from one place to another using the tractive force.Now the question is what kind of system comes into the tractive system. Such as railway engines, smart e-car etc.

Breaking

Braking in electric traction system is usually of two types one is electrical braking and mechanical braking. This one works equally well in both braking in a traction system. Electric Breaking is very much Efficient then Mechanical breaking.

See our MCQ model set

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Categories of Breaking

There are three types of traction electric braking

For which reason in this word(utilize wasted energy) is coming?

We need to think of some alternatives for the way the world is currently running out of fuel. Scientists and engineers have been able to find alternatives, but they have some problems that need to be addressed.

Some recharge agencies have said that in 10 years our world will start running out of fuel. Then the logistics of our vehicles will be solar energy or e-car.The only problem with driving an e-car now is the mileage.

This mileage is very important. If we want to drive the vehicles of the future properly, then we have to think about increasing the mileage.This concept is a concept that has been proven to be a theory but have not use in practice for some marketing issues.

A car never or always has acceleration. Sometime before the relationship is what we call an instance of retardation. In those cases, it is hoped that we can increase the mileage of all these vehicles by using the kinetic energy generators.

Operation

This type of E-car usually consists of two units, the first being the unit . Another unit that uses the wasted energy to recharge the battery.The main tractive motor is usually a DC series motor. Because the amount of torque required to run the entire car is the amount of torque.

That can be used to make a high speed motor into a high torque DC motor through a gear arrangement with the DC motor..

Lots of high speed motors at DC series motor no load. This high speed motor converts a lot of high torque motors through garage arrangement. First of all it is said thano car is always accelerate. The car has a 30% -40% retardation while running.A DC shunt generator will go through the speed conveyor belt at the speed that the high torque gears will produce during that retardation.

The generator will be connected to a battery that will charge the battery through the waste torque generated from the traction mechanism. Or when a car travels on a plane. Then the DC shunt generator battery will be able to recharge very well .

How much energy will be recovered

Since the amount of DC supply loss is very low. So hopefully the recovery system will not be like that. Until now, a four-cell car could provide 12 hours of backup using this system, now it can provide 16 to 17 hours of backup using that system. In the case where the distance is not constant, however, there is little evidence that the battery backup rate has increased by 20-30 percent since the introduction of this system.

Conclusion

In the next 10 years, some such systems will rule the world. Due to the current energy crisis and the fact that the environment is becoming more conducive to environmental pollution, the governments of different countries may stop fuel vehicles after a few years. They will only bring battery cars to the current market.

Next Decade completely depends on Renewable power sources. Solar car ,and Fuel cell cars are developed by some companies but the price is very high.Let's see if we will find a technology that will be affordable car price.

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How Effective Is The Hydrogen Power Industry As A Future Power Industry

2021-06-05T00:13:00.022+05:30

Hydrogen Power Industry

Introduction

The progress of powerless civilization. Hydrogen Power Industry is the solution

The power that we can use to move human life forward is the power of electricity. But now there is a shortage of this electricity all over the world and in producing this electricity we have damaged a lot of the environment.

Not just to generate electricity. We have done most of the damage to the environment by driving vehicles to run various mills. Natural disasters, outbreaks of unknown viruses, global warming, rising temperatures are all catastrophes.

At present we need to generate electrical energy from a medium from which there is no harm to the environment in the production of that electrical energy and we can produce the same amount of electrical energy now available from thermal power plants.One such energy source is hydrogen.

The calorific value of hydrogen is similar to that of contemporary coal and it does not produce any toxic gases in combustion which can harm the environment and the total amount of electricity produced is more than the amount of electricity in a thermal power plant.

Another source of huge energy is nuclear power but nuclear power is extremely dangerous and where one forgets the whole human society can be wiped out.Creating a Hydrogen Power Industry requires a lot of investment and the installation hassle is very high and controlled by skilled workers.

This is the only problem of the Hydrogen Power Industry.By 2050, about one trillion investments will have been made to use the Hydrogen Power Industry as a major power source. Also some companies have started making hydrogen fuel smart cars using hydrogen fuel like Honda. But the problem is that the market value of all these cars is so high that it is difficult for ordinary people to buy.

Fuel cell

A fuel cell is a type of battery that converts chemical energy into electrical energy. The difference between a fuel cell and a battery is that the fuel cell does not have to be recharged. Electrical energy is produced through chemical reactions of nothing through two electrons. The main sources of this chemical energy are hydrogen, oxygen, water.This type of material is cadmium nickel as the anode cathode of the fuel cell.

Hydrogen as a fuel

Some details about hydrogen at the beginning. The atomic number of hydrogen is 1, and the atomic month of hydrogen is 1.0064 u. And Hydrogen calorific value is 26555 kcal / kg.The calorific value of coal is 8000 kcal / kg.

Then it is generally understood that hydrogen fuel is about three and a half times the calorific value of coal. Where the overall efficiency of a thermal power point is 30%, the overall efficiency of the hydrogen fuel industry is about 40% to 50%.

Source of hydrogen in air

Hydrogen is found in only 10 percent of the air. In addition, the main source of hydrogen is the electrolysis method, which means that it breaks down water to separate hydrogen and oxygen. Usually the hydrogen producing industry follows this method.

Brief idea of how hydrogen is made as a fuel

Hydrogen power plants in the Hydrogen Power Industry it is not possible to use it separately as fuel in commercial hydrogen cylinders. Because hydrogen is highly combustible. Filling it into the cylinder and connecting it to the cylinder alley parallel to a specific outlet requires a lot of maintenance to use that achievement as fuel and accidents can happen most of the time.

Therefore hydrogen is generated inside the power plant by electrolysis method without exporting hydrogen from outside and this hydrogen is then used as fuel to generate electricity through turbines and alternators.

Hydrogen gas from some sources is used in power industry

Hydrogen gas is obtained from four types of sources on the basis of color

Brown Hydrogen
Gray Hydrogen
Blue Hydrogen
Green Hydrogen

Brown Hydrogen :It is usually obtained from coal. Brown hydrogen accounts for 15% of the total amount of hydrogen produced worldwide. One of the disadvantages of this type of hydrogen production is that the exhaust gas produced by combustion is a greenhouse gas i.e. co2. So it cannot be used in power industry also its calorific value is much less. But relatively cheap.

Gray Hydrogen:Gray hydrogen is usually obtained from natural gas and fossil fuels. Gray hydrogen is 84.1% of the total amount of hydrogen produced. Hydrogen is still used in most of the industries that use hydrogen in various industries around the world. One disadvantage of using it is. Its exhaust outlet gives rise to a greenhouse gas.

Blue Hydrogen:Blue hydrogen is produced by electrolysis. We know that electrolysis is an electrical system that separates oxygen and hydrogen from the power source in water by anode and cathode. It is completely safe and does not harm the environment. We can use that oxygen in one way or another.

Only 0.5 percent of the total hydrogen produced in the world is produced by this electrolysis method. And now that number is growing because the tilak licensing system is a much slower method of producing hydrogen, so this number is being hindered.

The source of green hydrogen and the source of blue hydrogen follow the same method of electrolysis.But to produce green hydrogen, electrolysis requires electrical energy from a renewable source, so it is called green hydrogen.Most of these renewable sources come from solar power plants. Resulting in much higher plant efficiency. Of the total hydrogen produced, 0.4 percent is green hydrogen worldwide.

Trending Hydrogen Generation Technology in Hydrogen Power Industry

Alkaline Electrolysis

Proton exchangeing membrem

In Alkaline Electrolysis process a electrolyte is use for producing Hydrogen so that electrolyte is KOH or NaOH is used . And supply voltage is connect to anod and cathod . We tend to produce hydrogen.One problem with this method is that the KoH destroys the anode cathode of the fuel cell for which the efficiency of the fuel cell is sold.

Here use a seperate which is made by nickel Other details include that the voltage efficiency of a cell is 52-59%.average cell voltage is 1.8-2.3 voltage. In this system Hydrogen production rate is 740 Nm3/h . And cell power density 1.2W/cm2 and current density is 0.2-0.4 A/cm2.

In Proton exchangeing membrem Electrolysis process use only water as a electrolite . Most convenient and economical Electrolysis process . Which is plan for future power generation . Here use anod and chathod for ionize the water and the OH- ion stored in anod thene use a circuit use for flowing the electron .

And electric current will be produced. Here approx maintaince charge is very low and Efficiency will be adjustable. The main membrem is made by polymer ,cell voltage is similar with alkaline Electrolysis power density is 4.5 w/cm2 current density will be 0.5-2.0 A/cm^2 . This Fuel cell Efficiency is 53-69% overall.In this Electrolysis Hydrogen production rate is 30Nm3 /h.

Plant blue print

This type of plants construct in a remote place . because the security and availablity of natural water . This type of plant mainly devide in 3 units.

1st Hydrogen Generation unit .

2nd Power generation unit.

3rd water treatment unit for Electrolysis water.

Hydrogen Generation unit is fully automated because the maintenance time is low . Generated Hydrogen stored a particular tanker for backup use . This unit have only one or more Hydrogen Generator . This Generator works as a producer of Hydrogen. Thend the Hydrogen goes a hydro engine that hydro engine .besically this Hydro engine is Internal combustion engine . Which drive by Hydrogen fuel.. then alternator generate electricity.

This is very brief information of Hydrogen Power Industry.Hydrogen Flower Plant Electrolysis involves the placement of hydrogen in a remote area or away from the plant because sodium hydroxide damages the hydrogen generator and can often lead to explosions outside the area.

Hydrogen powered Automobiles.

Basically hydrogen power automobiles use fuel cell When it comes to how to use hydrogen fuel in a car, the first thing to say is that the hydrogen fuel used in different cars generates hydrogen according to the electrolysis method through a fuel cell and that hydrogen builds trust in an internal combustion engine so that the car can move forward like this.

The main purpose of using fuel is from car smoke in the environment.One of the greenhouse effect gases that is released into the air for washing is carbon monoxide, carbon dioxide, etc. But such vehicles release oxygen into the air as an exhaust so that the balance of the environment is maintained even a little. The main disadvantage of such cars today is that they are much more expensive.Which is impossible for the common man to buy. In the future, more quality recharges are expected to reduce the price of such cars in the market.

Power generation quantity

The overall efficiency of this type of power plant ranges from 40% to 50%. Which means that the overall efficiency of the thermal power plant is not more than 25 to 30 percent. No matter how high the plant installation charge is, if you invest in such a plant, its output will always be adequate.

Environmental Impact

The Hydrogen Power Industry does not emit any gas into the environment. It can harm the environment. The oxygen produced in the process of hydrogen production can be reused commercially by collecting the oxygen that is produced. Or it can be released into the environment without harming the environment. Beneficial.

Conclusion

There has been a lot of investment to bring this kind of industry around the world. Some high quality countries have invested close to trillions in this type of industry. In their opinion, they will start planning such industries by 2026. And by 2050, this industry will move to a place that will be an alternative source of electricity for human civilization.

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2021-05-24T13:11:00.099+05:30

DC MACHINE AND ALTERNATOR OR SYNCHRONOUS GENERATOR

This Multiple Choice Question set for helping propose for which student are government job aspirants.This Multiple Choice Question Set mainly focused on DC MACHINE AND ALTERNATOR OR SYNCHRONOUS GENERATOR.

DC MACHINE

1. Which DC motor know as Constant speed motor
A) DC Series Motor
B) Induction Motor
C) DC Shunt motor
D) DC Cumulative Compound Motor
2. Which Motor Run at Over speed when noload?
A) DC Series Motor
B) DC Shunt Motor
C) DC Cumulative Compound Motor
D) None of the above
3. Lighting and Battery charging purpose use DC Motor?
A) DC Series Motor
B) DC Shunt Motor
C) DC compound Motor
D) None of the above

4. Which type Speed Control use in DC motor=

A) by flux and armature resistance
B) by flux and terminal voltage
C) by armature resistance and voltage
D) buy flux, armature resistance & terminal voltage

5. For the purpose of separate excitation which field is most preferred?

A) shant field
B) series field
C) both a&b
D) none of the above

6. Armature torque of DC series motor which proportion with armature current

A) directly squire d
B) inversely
C) inverse square d
D) directly

7. In DC motor torque increased 2 times with armature current increase

A) 8 Times
B) 4 Times
C) 2 Times
D) None of the above

8. What is the Disadvantage of high starting current DC Motor

A) Burning the armature due to excessive Heating.
B) damage the commutator and brush
C) excessive voltage drop
D) a,b &c

9. If Back Emf increase when Terminal voltage and armature resistance constant in dc motor the current Behaviour is-

A) No change
B) Increasing
C) Decreasing
D) none of the above

10. Mechanical Efficiency of DC motor Measured by

A) output power /Mechanical power in armature(Eb Ia)
B) Mechanical power in armature (Eb/Ia)/Input (V IL)
C) Output/input
D) None of the above

11. At Maximum developed mechanical power in DC motor Back Emf equal to
Of the Transformer-

A) voltage
B) voltage /2
C) voltage/4
D) None of the above

12. When Back Emf take Maximum value

A) No - load
B) Full load
C) half load
D) None of the above

13. Which loss change with speed in DC motor

A) Copper loss
B) Core loss
C) friction loss
D) None of the above

14. Constant Power Drive used speed control method is

A) resistance control
B) flux control
C) voltage control
D) None of the above

ALTERNATOR

15. For Rapidly change loads which Speed Control method use

A) flux control
B) Rheostatic speed control
C) voltage control
D) None of the above

16. In thermal power plant which Alternator use

A) Low speed
B) High speed
C) AorB
D) A & B both

17.A Salient-pole Rotor Alternator is-

A) Large Diameter and short axial length
B) Large diameter
C) short axial length
D) small diameter and very long axial

18. If 4 pole 50 hz 3 phase induction motor synchronous speed In thermal power plant Alternator Started by-

A) Damper winding
B) pony motor
C) A or B
D) None of the above

19. At the time of of parallel operation of an alternator power factor determine by

A) load power factor
B) prime movers speed
C) field excitation
D) none of the above

20. Over Excited Synchronous Motor behaves like a

A) Capacitor Bank
B) inductor
C) reactor
D) None of the above

21. Effect of cross magnetisation field on generated voltage is-

A) sinusoidal
B) sinusoidal with distortion
C) non sinusoidal
D) None of the above

22. A 2 pole 4 kv Alternator frequency 49.5 hz increase to 50 hz speed achieve with

A) 2800-3000 RPM
B) 2870-3000 RPM
C) 2900-3000 RPM
D) 2970-3000 Rpm

23. If need to increase the active power-

A) by changing governor
B) Increase excitation
C) Increase the speed
D) None of the above

24. If active power need to increasing -

A) Excitation increase
B) speed increase
C) voltage increase
D) None of the above

25. Salient pole Alternator speed is

A) 100-300 RPM
B) 1500-3000 RPM
C) 400-500 RPM
D) 120-400 RPM

26. Why cylindrical pole type Alternator small diameter and long axial length

A) speed
B) strong centrifugal force
C) Torque
D) None of the above

27. When Power factor is 1 the Alternator efficiency will be

A)Half
B) can not Determine
C) LOW
D) MAXIMUM

28. n Generators is connected parallel If frequency will try to increase which wiil increase

A) Excitation
B) Input
C) Voltage
D) None of the above

29. Where Mainly seen high speed turbine:

A) Thermal power plant
B) Hydroelectric power plant
C) Gas power plant
D) None of the above

30. If n Generators connected in busbar which parameter need to constant

A) Voltage and frequency
B) Voltage
C) frequency
D) None of the above
------------------------------------------------
Answer
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... Answer is A)

If you want to use this post as a question paper
This is second part of Multiple Choice Question set first part is
MCQ-1

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2021-05-18T17:19:00.076+05:30

MCQ QUESTION [ TRANSFORMER & INDUCTION MOTOR]

This MCQ set is practice purpose for competitive exams . This MCQ set follow upcomming Trends for Diploma and bachelor degree.This MCQ question only for Transformer and Induction Motor. This MCQ set not cover all the part of Transformer and Induction Motor

TRANSFORMER

1. Why is the open circuit test or No Load test of the transformer done to get what?

A) Total loss

B) copper loss

C) iron loss

D) friction loss

2. If primary current increases what will be the effect of leakage reactance?

A) increase

B) decrease

C) same

D) None of the above

3. What is the percentage of total flux is leakage flux?

A) 4 percent

B) 5 percent

C) 5.5 percent

D) 6 percent

4. At Maximum Efficiency of transformer Iron loss=

A) Copper loss

B) total loss

C) eddy current loss

D) None of the above

5. No-load power factor cos Φ0=

A) Iw/I0

B) Im/I0

C) I0/Iw

D) none of the above

6. If a Transformer input voltage 250 v and no-load current is 4.3 A at 0.5 (lagging)

A) 500 w

B) 537.5 w

C) 322 w

D) 516 w

7. What percentage of total loss is Copper loss of Transformer

A) 95 percent

B) 85 percent

C) 80 percent

D) 71 percent

8. If current increases in Transformer which loss will increases-

A) friction loss

B) Iron loss

C) eddy current loss

D) Copper loss

9. If flux density of Transformer is constant which loss remain constant

A) Hysteresis loss

B) Eddy current loss

C) Hysteresis and Eddy current loss

D) none of the above

10. Maximum efficiency of large rated Transformer

A) 60 percent

B) 55 percent

C) 85 percent

D) 95 percent

11. Which two things are similar are both primary and secondary winding

Of the Transformer-

A) current & voltage

B) resistance & leakage reactance

C) ampere-turns & voltage/turn

D) None of the above

12.

13. If Input voltage of the Transformer is 250v and primary impedance Is 1.2 kohm and secondary impedance is 2 ohm ,the truns ratio is ....

A) 25:1

B) 200:1

C) 60:1

D) 50:1

14. Primary and secondary linked each other of Transformer

A) Electrical link

B) magnetical link

C) mechanical link

D) None of the above

INDUCTION MOTOR

15. What is the power of maximum flux density in Hysteresis loss and Eddy current loss-

A) 1.6 & 2

B) 2 & 1.6

C) 2& 1

D) None of the above

16. When Rotor resistance/phase is equal to standstill rotor reactance/phase-

A) At Starting Torque

B) At running Torque

C) A&B both

D) None of the above

17. When we see rotor power factor 0.707 lag

A) Starting Torque

B) Running Torque

C) A&B both

D) None of the above

18. If 4 pole 50 hz 3 phase induction motor synchronous speed1455 RPM and Rotor speed 1355 RPM what is the rotor frequency?

A) 3.43 hz

B) 1.53 hz

C) 2.95 hz

D) 4 hz

19. If 3 phase induction motor Load increases what will be the effect on power factor

A) increase

B) decrease

C) same

D) none of the above

20. What is the similarity we follow between standstill induction motor and Transformer?

A) short-circuited secondary

B) open-circuited secondary

C) variable resistance

D) None of the above

21. DC shunt motor Torque characteristics similar with

A) DC series motor

B) synchronous motor

C) 3-phase induction motor

D) DC differential compounded motor

22. If airgap of 3 phase induction motor is increase what parameter is Effected

A) speed reduce

B) Decrease power factor

C) improve efficiency

D) speed increasing

23. If induction motor Rotor resistance of 0.008 ohm/phase

increase to 0.016ohm/phase, what is the effect on maximum torque ?

A) remain unchanged

B) increase by 100 percent

C) decrease by half

D) increase by 200 percent

24. Cause of 3 phase induction motor does not accelerate upto full acclaration

A) 7th Harmonic

B) 5th Harmonic

C) 3rd Harmonic

D) None of the above

25. If slip is 2% and 3 phase induction motor output power is 20 kw , what is the copper loss

A) 408. 16 w

B) 400.2 w

C) 395 w

D) 416.23 w

26. Choose the correct answer

A) Rotor rotation is equal to the direction of stator flux

B) Rotor rotation is opposite of the direction of stator flux

C) insufficient data

D) None of the above

27. Outer cage of Double cage induction motor

A) inductance is high

B) inductance is low

C) resistance is low

D) resistance is high

28. Which starter use for extra high HP Induction motor

A) DOL

B) Star-delta

C) Autotransformer

D) None of the above

29. Which Speed Control method is use in Squirrel cage induction motor

A) Pole change, voltage control, by VFD

B) pole change ,rheostatic control

C) cascade control

D) None of the above

30. During starting power factor will be

A) lagging

B) leading

C) unity

D) None of the above

------------------------------------------------

Answer

1) ... Answer is C)

W=iron loss .'. here W is no load input power"

2)... Answer is B)

L=NΦ/I . .'.X=2πfL so if"

3)... Answer is B)

5 percent flux is not linked with secondary

4)... Answer is A)

Iron loss = Copper loss

5)... Answer is A)

Iw=I0 cos =I0 cos I0=√(Im² +Iw²) Cos Φ0 =Iw/I0

6)... Answer is B)

7)... Answer is B)

8)... Answer is D)

P=I²R I increase P also increase

9)... Answer is C)

Flux density of Transformer is remain constant always and Hysteresis loss and eddy current loss voltage depending loss so if flux density constant voltage also constant..

10)... Answer is D)

11)... Answer is D)

12)... Answer is A)

13)... Answer is A)

k²= primary impedance/secondary impedance

14)... Answer is B)

15)... Answer is A)

16)... Answer is A)

17)... Answer is A)

18)... Answer is A)

s=((Ns-Nr)/Ns)=((1455-1355)/1455)=0.06.'. f'=sf,f'=0.06×50= 3.43 hz where f' is rotor frequency

Show Answer

19)... Answer is B)

If load increase speed also decrease so slip is increasing that slip increase the Rotor frequency if frequency is increasing then z is increased and power factor decrease.

20)... Answer is A)

21)... Answer is C)

22)... Answer is B)

23)... Answer is B)

24)Answer is A)

25)... Answer is A)

Rotor Copper loss/Rotor output=a/1-a=0.02/(1-0.02)=0.02/0.98 Rotor Copper loss = 0.02/0.96× Rotor output power (20×10³)=408.16 w

26)... Answer is A)

27)... Answer is D)

28)... Answer is C)

29)... Answer is A)

30)... Answer is A)

------------------------------------------------

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Cogeneration Diesel Engine Exhaust Outlet[PDF]

2021-05-10T01:56:00.020+05:30

Cogeneration Diesel Engine Exhaust Outlet

Cogeneration Diesel Engine Exhaust Outlet[PDF]

Cogeneration

Cogeneration is a process from waste energy to generate electricity. In detail Thermal power plant lot of heat energy is wastage from boiler and turbine due time of generation . Cogeneration is that wastage of heat energy to make electricity.

Would you believe that we use only 35% of the total electricity generated and release the rest into the atmosphere through energy. Cogeneration can solve this problem.We always know that energy is not destroyable but we can transform one energy to another energy.

This cogeneration classified in two categories:

Topping cogeneration
Bottoming cogeneration

Bottoming cogeneration

This topic is under Bottoming Cogeneration because we make direct westage power to electricity. Basically this copower generation is for only diesel Power plants .

This westage energy not only heats it, maybe a lot of exhausted thrust means when the diesel engine generates power by alternator that time the brunt fuel and gas in the exhaust of Diesel engine makes a huge thrust .

Diesel engine plant cogeneration

If we use this thrust in a low generation turbine and salient rotor alternator this thrust energy transforms to electrical power.Here westage power is exhausted thrust.

But there are some problems with transforming energy. Imagine theoretically it is very easy but practically it depends on some technical issues and economical issues.

But the energy that is once transformed in nature takes many years to return to that place, so it is not possible to judge it by money, so it is our responsibility to make this system work.

Cogeneration of a generating station requires some management. They are This Cogeneration A substation is needed to control the process. Because the diesel engine trust is not always the same, its speed may change at times.

For which the reactive power frequency of the alternator is will affect.For maintained the frequency and reactive power value of Cogeneration need a converting substation. This substation maintains the generation frequency voltage and power then permits flow of electric power.

In a plant all diesel engine exhaust outlet in a common outlet . The outlet have a nozzle the nozzle is varied by actual generation. Then the nozzle is focused on a turbine that bleeds like steam. A salient rotor alternator generates power to the grid.

It can maintained value like normal generation then supply it to the grid. Here implications of copower generation one time investment but this investment can increase the plant overall efficiency.

Conclusion

For general queries we need to know that if we generate 1 unit power we need 870g coal. This system is a unique recycling of energy .

Download this content as a pdf

Download

--------------------------------------------------

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Homemade Accurate Pulse Oximeter

2021-05-01T16:12:00.046+05:30

Homemade Accurate Pulse Oximeter

Pulse Oximeter

Pulse Oximeter is a Device which can check the oxygen level and BPM . In This Device main part is Electronic pulse oximeter sensor which can check the Oxygen level and BPM.

And another main part is battery and Microprocessor unit. But some time Marketise pulse oximeter sensor is very cheap na malfunctioned so we try to make Homemade Accurate Pulse Oximeter.

Introduction

In This Covid situation and also the crisis of oxygen, the Doctor 's suggestion is to always check the oxygen saturation level . If the Oxygen saturation level is below 94% please take doctors' suggestions.You can check your blood saturation level by using Marketise pulse oximeter.

But here have a problem most Marketise pulse oximeters have 2% error . In this situation 2% error is most panice. This 2% error is sacrificing your health.

Required Devices

In this topic we are demonstrating making an accurate pulse oximeter at home.. In the modern world there are a lot of compact devices. So If you have some technical knowledge you can also make this project for protecting you and your family in this crisis.

In This project we need Only two item first one any Microprocessor (Such as Arduino UNO, Arduino Nano, Arduino mega etc ) and last one A well priced Pulse Oximeter sensor and some jumper wire.

It is very economical project because normal Marketise Pulse Oximeter price all around 2000/- to 2500/- . Our project cost only all done 1000/- to 1500/-. Download the Arduino exe file on your computer.

just uploading the code which is mentioned below . And connect the Arduino with the sensor just like the circuit diagram which is mentioned below .

If any problem of understanding just continue reading with the circuit description.

Project Description

Pulse oximeter sensor have five operating pins. Pin names is VIN ,GND , SCL, SDA INT. here INT pin is not workable .

We just work first four pin . Pulse oximeter sensor supply voltage is 3.3 v so VIN connect to the Arduino 3.3 VCC pin .

And Ground pi to Arduino GND PIN . SCLpin connect to Arduino analog input pin A0 and SDA pin connect to analog input pin A1. Now all setup is complete just connect usb cable to your system and upload the code .

Before that the sensor can holding tightly a proper place because small jarking is compromised your result. For best result output in sensor for holding provide two holes . Hold the the sensor with nut bolt.

Result

When you connect the Arduino with system and uploading the code which is completely error less. Then go to serial monitor and check two output first one is bpm and another Oxygen saturation level.

When you take reading the hand holding without any jerking. Because the jerk concider as your bpm so here have some error .

Incase first time ouput with some error so don't panic , check your bpm two or more times there will the correct result. If you check more and more time so contact any medical specialists. And take all the precautions for your good health.

This project Run by this arduino code

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Google weather data compare with DHT11 Sensor data

2021-04-27T16:48:00.041+05:30

Google Weather Data compare with DHT11 Data

Google weather data compare with DHT11 Sensor data [ figure 1]

Introduction

Basically this is an experiment between Google weather temperature and humidity vs arduino controlled DHT11 sensor temperature and humidity data.

At last we check the both data and conclude the accuracy of both atmospheric devices.

Google weather data compare with DHT11 Sensor data [figure 2]

Google Weather

Google weather is a platform which is developed by Google. Google take the weather information like temperature and humidity etc.

From some verified source or website and reflects the data on Google weather and on the basis of that data Google predict related data such as possible rain, dryness etc.

And show on Google weather Google own created interface. Some user opinion the Google weather data some time not accurate and some time it is accurate.

Experiment

We take data from same time same day from Google weather and Arduino controlled DHT11 sensor after completeing project.

Device Information

DHT11 sensor is a device which can measure the weather temperature and humidity. It can work with any microcontroller such as arduino Uno/arduino mega/arduino nano/raspberry pi etc. DHT 11 manufacturer claims that it accuracy almost 95% with tolerance 1± % .we check separately DHT11sensor temperature vs temperature metre the reading difference between both device is 8%. Understanding with an example when DHT11 sensor read 30*C then temperature metre read 32.5*C. Next check the DHT11 sensor read humidity 69 and the Humidity sensor read 75. This analysis states that the DHT 11 sensor is not very efficient for measuring temperature and humidity. Let’s check what is the tolerance level between Google weather and DHT11 temperature?

Arduino setup

The DHT11 sensor has pins Vcc, GND,A0. We use it as a microcontroller Arduino uno. We connect the Vcc pin of sensor with 5v arduino pin and ground of sensor connected with Arduino ground. A0 pin of sensor connect with digital pin 2 of Arduino. Now USB cable connects with arduino and PC. Let’s upload the code. The code image is below Arduino software version.

Experimental data

Both readings are taken at 2.32 PM or 14.32 PM in the same location. At first temperature readings, when Google weather temperature show 39*C then sensor show 33*C. Almost 6*C difference.

In the temperature difference is too much inappropriate. When Google weather humidity show 33% then the sensor show 48% humidity difference between two medium of humidity data is 15%. This difference is huge and in appropriate.

Specially temperature data from both medium states that temperature of that particular time is above 30*C And the weather is SUNNY And humidity also states that NO POSSIBLE RAIN.

After the seeing result of experiment states that both data is also much difference but the true part of The data is both data indicating the same condition of the environment.

This experiment is limited by a limited number of process so In this case it is not possible to give a separate judgement.

Google weather data compare with DHT11 Sensor data [figure 3]

Conclusion

Weather is a natural phenomenon that cannot be predicted in any way, yet we may be using some devices that allow us to be aware of any natural disaster and these device can shoot those predictions.

Google weather data compare with DHT11 Sensor data [figure 4]

---------------------------------------------

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Amazing effect of LED lamp

2021-04-24T02:07:00.033+05:30

Why LEDlamp glows after switch off?

Amazing effect of LED lamp

Introduction

Why LED lamp glows after switch off? This is very common question in any competitive exam and interview. We find the reason scientifically and practically for this Amazing Effect of LED Lamp.

In a Led lamp are three part connector pins, driver circuit and LED cell. All parts are defined as their wattage rating. We know LED works only direct supply.

Circuit Description

But we use LED lamp in the AC supply .So we need a rectifier and an alternative Step Down transformer because if we use the Step Down transformer the system becomes very heavy. This Alternative arrangement is called Transformer less Rectification.

LED rectifier basically consists non polarized capacitor, diodes, Ferrite transformer Now some manufacturers don't use traditional diodes, a bridge IC DF 10 is used to make the PCB more compact. This is all the structural description of LED lamps.

Reason

Now describe what the reason is. Mainly two reasons for this to incident 1st one is the huge rate of capacitor when the pcb connects to Ac supply. Then the capacitor is charged up to full charging capacity.

When we turn off the LED lamp, the discharging time of the capacitor is not equal to charging time. Discharging is less than time compared to charging .The charging and discharging waveform shown below. At the Time of discharging the led lamp dimming gradually.

After some time it will take too much to completely off. Here some other reason is arise. Basically LED is diode it consist p type material and n type material and have junction barrier.

P type material takes holes and n type material takes free electrons. When capacitor charge then the free electrons pushed and cross the junction barrier and conduct with holes.*and the pulsed free electron energy released as from of light*.

So when discharging is incident the junction barrier acts as a capacitor and due to some kinetic energy is present in the electron some electron due to kinetic energy crosses the junction barrier and that energy releases a small amount of light.

As long as the kinetic energy is present, the electron will be in force. And light still glowing. This will actually cause the LED lamp to glow when you turn off the LED lamp. This incident doesn't depend on the price, quality, and wattage. If you buy any LED lamp which can be better price and quality you will see such incidents there too.

Conclusion

This effect is very natural for any LED lamp. This Effect is good for any LED lamp. It increases the long life. Every capacitor filtered device has same effect but cannot understand in any way. Some time many competitive exam or interview is common question now day.

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IOT Based Smart Ceiling Fan working

2021-04-16T16:59:00.047+05:30

How IOT based Celling fan work

IOT Based Smart Ceiling Fan working

Introduction

Here we discuss how IOT based Celling fan works,what is inside this celling fan, all functions and installation details.In this Modern world we need to know all about this type of autometion gadget.

Origin Of Brand

Orient Iot Based Smart Celling fan made by Orient which is a leading brand of Electrical home appliances in India and it is also part of CK Birla Group.This company can be trusted and relied upon with the naked eye.

Orient Aeroslim is one of the best smart IOT(INTERNET OF THINGS) based ceiling fans of india.

What is IOT(Internet of things) ?

IOT is a system which is purpose for control any Electronics equipment ,sensor over internet.

Classification

Mainly IOT is four type

1. Cellular IOT

2. Local and personal Area Network

3. Mesh network

4. Low power wide area IOT

Local and personal Area Network

This item is under Local and personal Area Network because this device IOT mediam is wifi module. And the all operation is done by limited area oriented.

Ceiling Fan Details

The motor quality is good.speed control is at a very precise level. you can control this fan via remote control, Bluetooth,and Orient app which is also available in play store.and along with a fan a LED lamp is provided which is also regulated by three dimming settings.

Structural Description

This fan build in five items 1) Motor 2)Down Rod 3) Blade set 4) shackle 5)canopy.

Motor Information

1200mm BLDC(Brushless dc motor ) ,RPM- 310 RPM, motor power factor 0.9 it can save 40% of energy (approx).

Type Of Speed Control

1) Traditional TRIAC based regulator.

2) Remote Operating

3) bluetooth control

4) voice control

5) IOT based ORIENT SMART APP.

Led Lamp

Remote can control the fan turn off ,turn on and also speed and control inbuilt LED lamp not only turn on turn off the light it also controls the LED dimming which have three dimming settings.

How Control Speed?

Bluetooth can control the same as it is the remote control.

A Google assistant like voice recognition AI robot can control the ceiling fan settings.

If you can use the command for turn off and turn on the fan and change the speed also.

You can also control it from your smartphone.just go to playstore then type ORIENT SMART an orange icon app and download it in your phone .

Then turn on your phone Wi-Fi and now need to configure the fan then you get 4 switches POWER, MODE,OSE,WIND SPEED .

Orient Smart App Modes

fan scheduling, Reverse Rotation sleep mode ,built- in- timer, scene switching light ,Turbo mode ,Breeze mode.

You can set the fan to your preference.

Inverter Technology

This fan with smart inverter technology can save energy 40% approx.and operate it at low voltage 160v .

Available colours

Available colours are Champagne Brown ,flem gold,white marble, white. The colour wish price varies.

Installation Details

Installation is nothing much complicated . It's Installation is same technique as normal Celling fan. Before the installation you need know all about the basis Electrical theories.

Conclusion

The fan has a very unique look. And the rating is almost 90%. The IOT control is accessible for multiple users without changing a silly setting.

This product is a demo of next generation domestic appliances.Maximum power rating is 45 watt .

The bleed designed on the basis of Aerodynamic rule.

So the multiple Speed control is acceptable for bleed design.

"This post is not a PROMOTIONAL POST.

This is only a review which is described in my blog.

I will share my experience with this smart ceiling fan"

--------------------------------------

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During Corona Epidemic 9 Minute power blackout in April 2020

2021-04-10T01:58:00.033+05:30

Behind the story of 9 Minute power blackout in this corona crisis

Introduction

The date was 05 th April 2020, 13 days after the first lockdown was announced in india fo Corona.

Shri. Narendra damodardas Modi states that "To end the darkness and uncertainty created by the Corona epidemic crisis, we need to move towards light and certainty by turning off all the lights in the house at 9pm for 9 munites on April 5 and lighting the mobile flashlights of the Pradeep, Candle, Torch . So that the great power of expression will be awakened which will be the proof to fight this corona crisis. And the proof will be that everyone is with everyone".

After Modi ji announcement, many great engineers in India started thinking that if they all turned off the lights in their houses at the same time, the load would fall and the voltage could increase and the grid could be blacked out.

Many have made such discussions on social media. Thoughts entered everyone's head. I really think we have to face a bigger disaster.

If somehow the grid is blacked out there could be a bigger catastrophe in between.

But our genius engineers accepted this challenge and many may not have experienced such problems as how to do it while sitting in discussion.

After much deliberation it was decided that they would reduce the power generation , load voltage all along with everyone.

The same theory was not as straightforward as it sounds. This complete account of how they accomplished such a difficult task is discussed step by step with time .

All this information is obtained from some personal sources.

Equation

At first we discuss two simple equation

f=NP/120

EMF EQUATION OF ALTERNATOR

Er.m.s/phase = 4.44 KpKcf ¢ T volts

If Load ⬇️ voltage ⬆️speed⬆️ frequency⬆️

Time wise Action

At time 8.50pm

The load frequency was reduced to 49.7 Hz.

The governor changed the settings and reduced both the voltage and the frequency, depending on the load at that time.

Attempts were made to keep this frequency constant for some advanced control systems and by those control engineers to operate them.

At time 9.00pm

At this time, everyone started to turn off the lights in their house and the load started to decrease.

As a result, the voltage started to increase and so did the frequency. At the time of 9.00pm frequency 50.3 Hz and at the time of 9.08pm frequency rise to 51 Hz in this 9 minute increase rate of frequency is 0.07 Hz.

If the frequency was more than 51hz, various generating stations would start tripping over frequency relays of the translation distribution. And the system would slowly move towards blackout.

Time(pm)	Frequency (hz)
8.50	49.7
8.51	49.772
8.52	49.844
8.53	49.916
8.54	49.988
8.55	50.06
8.56	50.132
8.57	50.204
8.58	50.276
8.59	50.348
9.00	50.42
9.01	50.492
9.02	50.564
9.03	50.636
9.04	50.708
9.05	50.78
9.06	50.85
9.07	50.92
9.08	51
9.09	51.062

[There is a cosmic catastrophe happening here that we will need to take a look at something that is indirectly very important.]

Since there was a lockdown at that time so many industries were closed at that time, the traction load was much less.

Mainly load was some commercial load, some other load and most domestic load.

According to the 2019 & 2020 energy statistics

Our total energy generation consumption

Industry - 42 %

Domestic- 24 %

Agriculture- 18%

Traction -2%

Others - 6%

We know that load fluctuations are the highest in the industrial sector.

Since no industry was running at that time and LDC(LOAD DISPATCH CENTRE)kept the frequency low from the beginning, the frequency did not go up. And for which the frequency has been controlled.

At time 9.09pm

Load increasing voltage takes place at rated value also with frequency. But some voltage shoot up happens this will describe the generation voltage graph.

If the generation decreases the rated value the generating station faces some loss. But if it is the matter of natural security, so is the diesel set ready for any emergency call. If the power grid fails the whole line changes to backup.

Conclusion

"The citizens of our country have never understood why such a big incident has taken place behind this incident

My post is a tribute to the engineers of the company who are involved in such a big event and who handled such a big event in this brutal Corona epidemic".

--------------------------------

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Experiment load angle(δ) VS power factor(Φ)

2021-03-31T00:25:00.033+05:30

Experiment Load Angle vs Power Factor

Experiment load angle(δ) VS power factor(Φ)[figure 1]

Introduction

This is actually a mathematical experiment of Synchronous Generator we are trying to show what effect the change in Load angle will have on the different power factor (lagging and leading) and vice-versa.

Constant Data

At first we take some assumed value of synchronous generator.

Line voltage (VL)= 250 V

So, Phase voltage (Vp)=250/√3=144.3 V

Armature resistance (Ra)=0.8 ohm

Synchronous reactance (Xs)=1.5 ohm

Synchronous impedance (Zs)=0.8+j1.5=1.7∠61.92°

Power rating of Synchronous Generator(P)= 12 KVA

P=√3 VL IL

load current IL= P/√3 VL

So,IL=((12×103)/(√3×250))=27.71 A

Vp =144.3∠0°

Zs=1.7∠61.92°

We are take Power Factor 0.8 and 0.9 lagging and leading both

When Power Factor lagging then use 0.8 and 0.9 and record the Vp and δ

And power factor leading then use 0.8 and 0.9 and record the Vp and δ

Lagging

Power factor 0.8

Ip=27.71∠-cos-1 0.8

=27.72∠-36.86° A

Ep=Vp+Ip Zs

=144.3+(27.71∠-36.86°)×(1.7∠61.92°)

=144.3+42.67+j19.95

Experiment load angle(δ) VS power factor(Φ) [figure 2]

=186.97+j19.95

=188.03∠6.09° V

Power factor 0.9

Ip=27.71∠-cos-1 0.9

=27.72∠-25.84° A

Ep=Vp+Ip Zs

=144.3+(27.71∠-25.84°)×(1.7∠61.92°)

=144.3+38.07+j27.74

Experiment load angle(δ) VS power factor(Φ)[figure 3]

=182.37+j27.74

=184.46∠ 8.64° V

Leading

Power factor 0.8

Ip=27.71∠cos-1 0.8

=27.72∠36.86° A

Ep=Vp+Ip Zs

=144.3+(27.71∠36.86°)×(1.7∠61.92°)

=144.3-7.19+j46.55

Experiment load angle(δ) VS power factor(Φ)[ figure 4]

=137.11+j46.55

=144.76∠ 18.75° V

Power factor 0.9

Ip=27.71∠cos-1 0.9

=27.72∠25.84° A

Ep=Vp+Ip Zs

=144.3+(27.71∠25.84°)×(1.7∠61.92°)

=144.3+1.8+j47.07

=146.1+j 47.07

=153.49∠ 17.85° V

Experiment load angle(δ) VS power factor(Φ)[ figure 5]

Data Sheet

At first reault We see that when primary voltage increases the load angle decreasing order at the power factor 0.8 (lagging)

And second result states that when primary voltage decreases the load angle increasing order at power factor 0.9 (leading)

Power factor(lagging)	Ep	Load angle(δ)
0.8	188.03⬆️	∠6.09°⬇️
0.9	184.46⬇️	∠ 8.64°⬆️

Next sheet states that We see that when primary voltage decreases the load angle increasing order at the power factor 0.8 (lagging)

And second result states that when primary voltage increases the load decreasing order at power factor 0.9 (leading)

Power factor(lagging)

Load angle(δ)

0.8

144.76⬇️

∠ 18.75°⬆️

0.9

153.49⬆️

∠ 17.85°⬇️

Conclusion

This is a Theoretical Experiment with Load angle vs power factor. This Experiment essentially applied in many generating stations . This Experiment helps the governor settings of alternator.

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DC machine single and double layer winding torque equation

2021-03-27T16:21:00.029+05:30

DC machine Torque Equation

DC machine single and double layer winding torque equation[figure 1]

Introduction

In DC machine two type layer winding is used according to its torque.We are trying to make understand with some equations the DC machine torque of both layer winding are equal or not .Or in other words, how can that level effect the torque equation.

Let's see.

DC machine single layer windings torque equation

DC machine single and double layer winding torque equation[figure 2]

r=armature radius

l=each conductor length

Z=Total number of armature conductor

nc=number of conductor

i=current in each conductor

a= number of parallel paths

B=flux density

φ=flux per pole

P=number of poles

∆F= instantaneous of force

∆T= instantaneous of torque

Forces in each conductor (F)=B.i.l newton

Torque=fource×distance

Torque in one conductor =F.r newton-meter

Total armature torque=Z.F.r newton-meter

Ta=Z(Bil)r

Ta=ZBilr

Ta=Z(φp/a)(Ia/A)lr [.'.B=φp/a, i=Ia/A]

Ta=Z(φp/(2πrl/P))(Ia/A)lr [.'. a=2πrl/P]

Ta=Z(φp/(2π/P))(Ia/A)

Ta=0.159ZφpIa P/A

Ta ∝ φpIa

Ta ∝ kφpIa

This contain show Torque equation of single layer winding

Torque Equation Of Double Layer Winding in Dc machine

DC machine single and double layer winding torque equation[figure 3]

∆F=2ncBlIc

∆F=2ncBl Ia/a [.'. Ic=Ia/a ]

∆T=2r(∆F)

∆T=4nc Brl Ia/a

So, dT=4(Z/4π)Brl Ia/a dθ [.'. nc=z/4π) ]

Total torque between two brushes.[0-> 2π/p]

So, Ta =Z/π Ia/a ∫0(2π/p) Brl dθ [.'.

φp = ∫0(2π/p) Brl dθ]

Total armature torque ,

Ta =z/π Ia/a P/2 ∫0(2π/p) Brl dθ [ p/2= is for torque of one complete rotation of armature]

Ta=ZIaP/2πa =Z/2π P/a

=Z/2π P/a φp Ia

=0.159 ZP/a φp Ia

Ta ∝ φpIa

Ta ∝ kφpIa

The Torque equation of both types of layer of machine is the same but if their different constant values so the actual torque depends upon their content values.

Conclusion

In this equation states that the constant value changes with the torque. In this equation helps to find out the application wise required torque wish choose the single layer and double layer winding.

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DC machine wave and lap winding with numerical analysis

2021-03-16T01:19:00.032+05:30

Classification of DC machine windings

DC machine wave and lap winding with numerical analysis [figure 1]

Classification

Mainly DC machine have two type of winding

1) wave winding

2) Lap winding

Wave winding

In DC machine armature coil connected to series with commutator with distributed two parallel path with respect of number of pole called wave winding. Wave winding is a High voltage winding.

DC machine wave and lap winding with numerical analysis [figure 2]

Lap winding

And, In DC machine armature coil connected to series with commutator with distributed two or more parallel paths as the number of pole called Lap winding. Lap winding is called Low voltage. Some time difficult to remember which winding is high voltage and which one is Low voltage. So we are find a short tips , their are.

Low =Lap

High=wave (sea wave is always High).

DC machine wave and lap winding with numerical analysis [figure 3]

Mathematical Analysis

In way two winding classifications are done because their voltage rating is different with respect of different current rating but the power will be same as well as torque and speed remain same with power.

When DC machine required for low voltage rating then preferred lap winding and DC machine required for high voltage then use wave winding.

This theory will better understand with some numerical model and some assumed parameter of DC machine.

We know, A is number of parallel paths

When Wave winding is use the A =2

And lap winding is use the A=NUMBER OF POLE(P)

At first we need some assumed data

P=4 ,Z=1000, Φp = 0.02 wb ,N=1500 RPM

So, Eg (lap)= Φp Z N P/60 A= (0.02×1000×1500×4)/(60×4)= 500 volt

Eg (wave)= Φp Z N P/60 A=(0.02×1000×1500×4)/(60×2)= 1000 volt

The numerical analysis says that the generated e.m.f in lap winding is 2 times greater then the wave winding.

Next we see the current behaviour of lap and wave winding.

Current in coil is Ic

Ic(lap)=a Ic=4Ic

Ic(wave)=a Ic=2Ic

The current in coil says that the current in wave winding is 2 Times more than the lap winding.

Power(lap)=Eg (lap) .Ic(lap) = 500.4Ic = 2000Ic

Power(wave)=Eg (wave) .Ic(wave) = 1000.2Ic = 2000Ic

After the conclusion the numerical analysis and theoretical analysis is justified.

If both winding has different voltage a current rating the power always same in nature.

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AC Machine Power factor angle relation with leakage reactance

2020-10-17T01:59:00.037+05:30

How different power factor angle and input primary current effects on leakage reactance of the AC Machine?

What is leakage flux?

Basically AC Machine leakage flux is some amount of primary flux would the amount of input given to the primary due to this leakage flux in the magnetic circuit is not found in the whole secondary. Not linked with secondary. So this wastage flax is called leakage flux.

If we imagine an electrical circuit where the reactance, drops some amount of current, In the same way in magnetic circuit the amount of flux that is formed in the total number of primary cannot be induced in the flux secondary.

AC Machine Power factor angle Between leakage reactance [figure 1]

AC Machine Power factor angle relation with leakage reactance[figure 2]

What is leakage reactance ?

In AC Machine some amount of drop or loss of flux in magnetic circuit . So this wastage called leakage reactance.

If any how this leakage reactance change to control value thus its effect falls on the input current and the power factor.

So how is the leakage reaction related with the power factor that is describe in the mathematical equation of AC Machine.

We take 3 power factor angle for realization changes from.

When power factor angle is increased, the primary current also progressive order,

AC Machine Power factor angle Between leakage reactance [figure 2]

Let us see where we get the values of different current for different angles of the power factor in this equation.

Leakage current with different Power factor angle 10°,30°,60°

AC Machine Power factor angle Between leakage reactance [figure 3]

Increasing power factor angle with decreasing leakage inductance,Primary Leakage reactance X1= 2πfL 1

Leakage inductance is directly proportional with the leakage reactance, it means increasing order leakage inductance always increase leakage reactance.

Equation

If we try to find out the mathematical equation of relation between leakage reactance vs permeability and Amp-turns.

Φ= B A wb

B= flux density

A= per unit area

Where,B= μ0 μr H is medium

B=μ0 H is air

H = Magnetic field intensity

μ0= absolute permiablity

μr= relative permiablity

H=mmf/l=NI/l

In the situation we are try to say ae if ampere turn increase, intensity of magnetic field also increase and increased the flux density and flux as a result of leakage reactance increasing.

Conclusion

In this Topic we are just show in AC Machine the what ammount leakage current in different power factor.

Project Convert 1 Φ phase induction motor to repulsion motor

2020-08-30T02:01:00.049+05:30

CONVERT REPULSION MOTOR TO ARDUINO BASED SINGLE PHASE INDUCTION MOTOR

Project Convart 1 Φ phase induction motor to repulsion motor [figure 1]

Introduction

This Project we try to a Single phase induction motor convert to a REPULSION MOTOR using Arduino UNO and single pole double throw relay.

In this project make an arangment which is Arduino based and relay whre this arangment can control the rotation direction Which is commonly used in industrial drives.

Single Phase Induction Motor

Single phase induction motor speed, torque, slip depend entirely on double revolving field theory.

Project Convart 1 Φ phase induction motor to repulsion motor [figure 2]

When supply current is sent into the main winding, alternating flux is formed which is not rotated alon when induced.

If AC supply is sent in an auxiliary or running winding, alternating flux will also be created there but it will work in the opposite direction of main welding.

Since the magnitude of their flux is equal, so the net torque is equal, so the winding cannot make any rotation torque.

Two type of MMF generated in Single phase induction motor BACKWARD MMF and FORWARD MMF.

This is an overview of Double Revolving Field Theory.The main reason for not making the rotation of the winding is the flux of two MMF equal magnitude.

The magnitude of flux depends on the inductance of the winding.If the inductance of any winding is less then its magnetic flux magnitude will be less MMF and torque will be less. And the motor will make rotation in the specified direction.

We know that the rotating magnetic field is created for the rotation like three phase induction motor and that rotating magnetic field creates the three phase power supply which creates 120° phase displacement which causes the motor to rotate.But single phase induction motor does not have that advantage.

There is only one phase so it has to make phase displacement which provides a capacitor which is rated at 2-2.25 mF.The capacitor creates a 90 ° phase displacement between the two windings.The arangment and code described following below.

REPULSION MOTOR

Repulsion motor is a series ac motor where the motor brushes are short circuited by a low resistance wire. When supply apply to stator the stator make North pole and South pole and MMF .

This MMF cuts the rotor part due to faraday electromagnetic induction rotor will magnetize and generated EMF makes MMF and poles which is oposite of stator pole it means repulsion torque will generate and other hand stator poles are not constant due AC supply use .

when the poles change to other cycle the attraction torque generate. So this principle Repulsion motor works.

Single Phase Induction Reverse Rotation

Let's check single phase induction motor rotate reverse direction.Looking at the figure, we can see that if we can send the power supply to Terminal A and Terminal B in reverse direction, then the direction of the net magnetic field will change.

As a result, the MMF of the magnetic field will rotate and the motor will reverse rotation.

But it is difficult to send forward and reverse direction supply again and again so an SINGLE POLE DOUBLE THROUGH RELAY will help here which will enable the power supply to send power supply in forward and reverse direction as required and the rotation of the motor can be changed by relay as required and Arduino Microprocessor control the relay.

Arangment

In This project we use SPDT Relay operate 12 v dc supply and have a common pin , NO and NC pin.The Arduino 7 Digital Input pin engaged with this common pin and two capacitor terminal are connected in NO NC pin .

The algorithm always states HIGH the forward rotation happens after some delay it will set it what delay you want this advance not afford in repulsion motor and when LOW then Reverse Rotation . If you calculate 1 Revolution time the easily set the delay timing .

In this project prevent from Repulsion motor loss.

Conclusion

In this Project we try to save the loss of power during rotation of repulsion motor. And this project change the conventional Electrical equipment trends.

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In Circuit Breaker Used Remote Operating Devices

2020-08-30T01:12:00.033+05:30

Remote Operating Devices in circuit breaker

In Circuit Breaker Used Remote Operating Devices [figure 1]

Introduction

Circuit Breaker Use for Break the supply when fault entering in the any electrical system.We are described the what is the devices use for behind the remote operation in circuit breaker. Only which device describing that are essentially use for remote operation.

Tripping coil

In Circuit Breaker Used Remote Operating Devices [figure 2]

The tripping coil is a small electromagnet that helps to release the spring of the moving contact of the circuit breaker.

The structural features of the tripping coil are that it looks like a small motor, its parts are sensing coils or electromagnets, moving magnetic core and spring.

The sensing coil has a moving iron core and is pulled upwards with spring tension.

When the relay sends a signal ,the auxiliary voltage supply makes the tripping coil energized and pulls the moving iron core downwards then the spring of the moving contact of the circuit breaker is released and closes the circuit.

Number of Tripping coil

A circuit breaker has two tripping coils, one coil working if the first tripping coil is not working then relay command sent to another tripping coil simply another tripping coil is the backup support purpose .

Function of Tripping Coils

When the circuit is closed, the three will close the circuit at the same time. If the closing time of the three poles is delayed for any reason, then the system will become unbalanced.

And these two tripping coils are kept in regular maintenance .The working tripping coil and the backup tripping coil operates remote interlocking.

That's the way it works,The relay sends a signal to the first tripping coil and if the first tripping coil does not work in some time deals, the relay sends a signal to the backup tripping coil for opens the circuit.

Tripping coils usually have three leads for two lead inputs for one ground.Figures and diagrams illustrate how the tripping coil looks.

Spring charging motor

Spring charging motor Circuit breakers usually have two springs, one to closing spring and the other to opening spring . An open and close circuit can usually be made with a spring, but for safety reasons and to avoid applying too much force to a spring, the circuit is open and closed with two separate springs.

The charging motor in the circuit breaker is used to tension this closing spring.The type of the charging motor usually uses a universal series motor with a gear box arrangement.

The Motor rating depends on circuit breaker rating. Usually the rating of all these motors is such that the voltage rating is 110-125 or 220-250 VDC or VAC and RPM 2000 to 6000 and wattage 80 to150 starting current 20-40 A and normal current 4-8A starting and normal current depends on the voltage rating.

The motor selection is based on the rating of the circuit breaker because if the rating of the circuit breaker is higher than the spring tension is more then the rating of the motor increases with the rating of the circuit breaker.

Universal motors are commonly used in low rated circuit breakers and squirrel cage induction motors in slightly higher rated circuit breakers.

Closing coil Closing coils look like tripping coils. Structural variation and working tripping are one like coils. The only difference is their work.

The closing coil gives circuit breaker instruction to close the circuit just as the tripping coil makes the circuit trip.Usually the closing spring is held by the iron core of the closing coil.

In real instruction the closing coil pulls down and the moving contact fixed contact is held together by the spring.

Conclusion

Tripping coil is the main part of remote operation in circuit breaker . And the Spring charging motor use for charging the charge the spring.

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How Harmonic Excluded in Neutral Transformer

2020-08-08T22:44:00.031+05:30

What is the purpose of using a neutral transformer? And Why is tertiary winding used in neutral transformers?

How Harmonic Excluded in Neutral Transformer [figure 1]

How Harmonic Excluded in Neutral Transformer [figure 2]

Introduction

We know that a delta connection does not have a common point through which fault current and Harmonic can flow.So this is a problem with delta winding transformers.

Fault current comes to the delta winding transformer and cannot be excited or grounded as there is no common point then Fault current burns the windings. Show this purpose neutral transformer used.

Neutral transformer

The neutral transformer creates a low reactance path for fault current exits or grounded. Also one more thing to do, any harmonic component comes in line helps to exclude harmonic component.The tertiary winding of the neutral transformer creates a low reactance path and excludes the third harmonic component.

Tertiary winding

Tertiary winding looks like figure 1.Basically we know that if there are high and low percentage of reactance paths in the same circuit, fault current always tries to flow in the low percentage of reactance path.The percentage reaction of the neutral transformer is 35% of the reaction of the power transformer.

Tertiary winding works

So the fault current will always flow towards the neutral transformer.And how tertiary winding exclude harmonics this are.The third harmonic current is mainly responsible for the distortion of the supply voltage.

As the neutral current enters the fault current for the low reactance path, the harmonic component is added to the winding with the fault current.Saturates the core very quickly when it comes to harmonic component winding.

Elemination of Harmonic

This saturation is essential to protect the main flux waveform from distortion.High magnetic flux lines form when the harmonic component enters the core.The oil and tank body in the transformer create a high reluctance path .

High Flux line is reduced by oil and tank body results reflect the voltage waveform .And for which the main flux becomes distortionless and the voltage waveform becomes harmonic component less and sinusoidal. Distortionless low voltage waveform is created due to high reluctance of oil and tank body.

It is need to know elaborately , input current with harmonic component when entering in primary of neutral transformer the i/p current created flux in core the created flux produce many flux line in core most number of flux line are loss in oil (for cooling cooling and insulation purpose) and tank due to high reluctance (flux not travel high reactance path) so many of harmonic component are neutralize.

Neutral transformers only use delta connected primary and secondary winding , Star connected not use neutral transformers because Star connected systems have proper ground arrangement.

In case some harmonic component try to enter a power transformer even if the neutral transformer is still working ,the differential relay breaks the supply from load the transformer goes to shutdown condition.

Conclusion

For all these reasons the oil test of the neutral transformer is done regularly and the oil change is done regularly. Now day the Transform Oil Test uses help of some embedded systems that use alarm systems for regular oil maintenance to schedule oil tests at regular intervals.

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The Role Of Harmonic In Power Generation

2020-08-02T16:32:00.028+05:30

Harmonic

The Role Of Harmonic In Power Generation [ figure 1]

Introduction

The simple answer is Electrical power generation is never available without harmonic components let us have a clear understanding of this.

Hysteresis loop

The Role Of Harmonic In Power Generation [figure 2]

Hysteresis loop is a graphical indicator which is defined if any feromegnatic material energies by supply a Electrical field permanently stored for this represenation called Hysteresis loop matter is completely related to the hysteresis loop or B-H curve of magnetic material or can be called b-h curve of magnetic material.We will understand step by step how it is related.

Generation without Harmonic is possible?

The Role Of Harmonic In Power Generation [figure 3]

When the alternator generates power, its speed is related to the voltage.That is, if the speed is less than, the voltage is affected or it can be said that the voltage is proportional to the speed.In addition, if the speed is linear, then the voltage waveform will be sinusoidal.The result will be induced flux sinusoidal.

The current may not be sinusoidal as a result of induced flux. Current webform distortion comes.Distortions in the webform are called harmonic or harmonic components.The cause of this distortion is usually attributed to the B-H curve of ferromagnetic material.

To simplify the content, a brief discussion on B-H curve was given.The B-H curve is one such property of ferromagnetic materials.Although some ferromagnetic materials are isolated to have electrical energy, some amount of magnetic energy resides in the material.

The amount of magnetic energy depends on the nature of the ferromagnetic material.That is, even though no generator produces electrical energy, some magnetic properties are present in it.For this magnetic property some small amount of current can flow in the circuit called magnetizing current or no load current.

When the alternator starts running its speed is maximum then voltage induced flux is maximum and current flows for induced flux in the circuit it creates distortion for the magnetizing current i.e. there is a harmonic component in the output current.What Harmonic looks like is said to be one or more of those webforms created on the main waveform.

Since Harmonic Webform does not maintain any general webform, it is not generally possible to measure the various parameters of the waveform.

Harmonic waveform has to take the help of Fourier series to convert Generalized WaveForm.Harmonic Waveform converts generalized waveform through Fourier series and then different current parameters are obtained.

The generalized parameters are indicated by excluding the harmonics that are used to measure the output current during power generation.From this it can be said that the harmonic is above the fully related magnetizing current.

The magnetizing current depends on the B-H curve. Just as the B-H curve cannot be excluded during power generation, the harmonic component cannot be excluded.

There are usually two types of harmonics, odd harmonic and even harmonic.We know that harmonic waveform are part of the main waveform.

If we imagine a half cycle being divided by more than one waveform, we can see that those parts are only being odd or even order . In between odd harmonic is dangerous for Electrical equipments .

Conclusion

It causes loss in power system , sudden voltage drop, Induction Motor crawling effect etc . This odd needs to substrate from system.Even harmonic Maintained as selfly generalized order.Farther Details will be given in any other content.

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| Smart IOT based surge arrester diagnose device |

2020-07-28T02:08:00.041+05:30

Surge Arrester Diagnose Device

Smart IOT Based surge arrester diagnose device [figure 1]

Smart IOT Based surge arrester diagnose device [figure 2]

Introduction

Surge arrester is a protection device which can Acts as shield against the lighting or any kind of surge.We will first understand how a lighting arrester works and then discuss its diagnose device.

Construction of surge arrester

Lighting Arrester consists of two arc gaps and a non-linear register in terms of structural demonstration.Lighting arresters are kept with one end load and the other end earthing.

What is Lighting Arrester Non Linear Resistance is usually temperature dependent.That is, when the temperature rises, the resistance decreases and when the temperature decreases, the resistance increases.

When there is a surge on the line, the temperature in the line increases and the resistance of the non-linear resistance of the lighting arrester decreases.Utilizing this property of non-linear resistance, the lighting arrester can bring the surge into itself and ground it.

Other normal times when the voltage is limited with line voltage the line temperature is low . It means surge arrester only works when surge comes in line.

Surge can come in line all the time. This surge arrester is kept in regular maintenance to protect other devices from damage.

But sometimes surge arresters can damage other devices on the surge line due to lack of maintenance for some reason. The surge arrester diagnose device is used for this maintenance problem and Protect other device from surge.

Surge arrester also use as a diagnose device continuous monitoring and recording the data amount of surge comes in line and predicting the surge arrester damage internal part automatically alert to operator for maintenance.

Let's talk a little more about this device.

Advanced Automation of surge arrester

Now a day surge arrester is used for diagnostic systems and is performed automatically by the Internet of Things(IOT). Device Internet of Things (IOT) monitors the data from surge arresters.

It can detect surge temperature, line voltage , leakage current , humidity and predict the data if any abnormality in surge arrester then send an alert signal through IOT network to the control room.

Control room informs the maintenance team. Speciality of IOT based diagnostic device for surge arrester is the whole system does not need any external power supply and signal send are received via wireless connectivity.

If any abnormality in this diagnostic device for surge arrester this signal is also reported to the operator. Which makes this device much more reliable.

This device is highly used in air insulated substation and gas insulated substation.

Other important features are that the system is able to record past data , enables wireless connectivity across a wide area, easy to install and send data and receive secure network protocol.

This device is capable of calculating the lifeline of a surge arrester.This type of device is capable of communicating with the substation automatically. And timely maintenance saves a lot of damage as a result with real time analysis.

Conclusion

Economically this device is efficient and also quite efficient in terms of operation. In the future, such devices could give a new direction to the electrical system.

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Natural Lightning Effects on Coil based equipment

2020-07-25T01:19:00.028+05:30

Lightning can be harmful to coil based equipment if the equipment is not connected to the supply or switched off from supply line?

Natural Lightning Effects on Coil based equipment [figure 1]

Natural Lightning Effects on Coil based equipment [figure 2]

Introduction

Natural Lightning have many theories .Before discussing this topic, let us first say that this subject has been discussed by many theories, which are significant for discussing this subject and The theory that will help readers understand this is discussed here. This theories defined many way but the basis structure of theory always same.

What is Natural Lightning?

When water evaporates from the earth's surface and rises to form clouds. Rain and thunderstorms occur when that cloud loses its water holding capacity.Now the question is why lightning.

The particles of water that rise from the surface of the earth,In it small water particles have negative charge and large water particles have positive charge.

These small water droplets rise to form negatively charged clouds and large water droplets form positively charged clouds.

We know that positive charge particles and negative charge particles always attract each other and try to neutralize itself.

So a positively charged cloud and a negatively charged cloud are attracted to each other and they try to neutralize each other, resulting in a huge amount of electricity,heat, light and noise this is called Natural Lightning. The amount of Lightning depends upon the amount of charge interact each other. We know electric current always flow low reactance path. When charge particle interact each other . A huge neutralize strike are developed.

This lightning strike finds a low reactance path or try to ground. When lightning occurs, lightning tries to find a low reactance path, as the amount of plantation on the surface is high. So for him, lightning is seen to be taught more in plants and so lightning tries to hit in that direction.

lightning strikes

We know that the Earth's surface is a huge reservoir of positive charges so negatively charged clouds are sometimes attracted by the Earth's surface.When lightning strikes the earth's surface, it generates a lot of electricity.This is how lightning is created on the earth's surface. Let us now answer our question.

If the power supply of any electrical equipment is off or the power supply is closed circuit but if the equipment is internally short circuit then there is a highly chance that it will be damaged by lightning.

When lightning strikes the surface, a large amount of electrical energy is generated and mutually linked with nearby coil based electrical instrument according to the destiny of the mutual inductance. Always mind lightning strike always find low reactance. If it can be find nutralize electricity is huge . If it mutualy inducted to any coil the coil will brun .

Example: Trees are the most low reactive objects on Earth. Lightning strikes when falling into a tree. Then the neutralized electricity and any coil equipment can be destroyed.

In other words, the electric current generated by the lightning creates the mutual inductance of the close circuit coil near it and for this mutual inductance current flows through the coil since the amount of lightning voltage not limited so induced current in coil is not limited.

The most important thing about burning the coil here is that the coil is internally short circuited. Also another issue is whether the coil may burn out if the electrical instrument is not supplied but connected to the electrical circuit.

However, the huge lighting voltage can enter the instrument through the operating switch of the instrument. Since the distance between the two contacts of the switch is very limited, the huge lighting voltage can easily reach from one contact to another through the arc and burn the coil.

Some devices designed to solve this type of problem The device used to solve this type of problem is the lighting arrester.The function of a lighting arrester is to store the positive charge on the surface.

When lightning strikes, the lightning will attract the lighting arrester and the heavy lighting voltage will be grounded through the lighting arrester.

The lighting arrester will attract and ground the lightning before the huge lighting voltage is available to induce in any coil based electrical instrument.

Lightning protection equipments

The trident shape in the house usually uses a surge arrester. It is usually made as an alloy of cadmium copper. Cadmium provides firmness and copper creates low reactance pathways. Usually a surge arrester creates a cloud of negative electrons. And through which the lightning surge is attractive and due to the low reactance path the lightning arrester becomes grounded through it.

Also in case of transmission line low voltage or high voltage a ground war catenary is used to intercept the lighting surge. This type of system is usually the most active in traction systems. Where surge can pose a big danger.

Also the poles or structures of the transmission line are from such a high direction. And the lighting charge is more attractive for the flow of negative electrons in the layer.

Even if there is a catenair net at the electrical substation, it is not enough for lightning surge. For this a special device is used which is called Sarge Arrester. It is usually used to protect any equipment.

Lightning Arrester Installation

Usually lightning Arrester use a specific earthing system . Depending of the system capacity the type of earthing system use . Some time rod earthing can be use or some time pipe and sheet earthing use. The lighting Arrester Install in Rooftop .

Lightning Arrester connected to ground equipment by galvanized wire for reduce the cost of installation . But due long life and properly made low reactance Copper wire must be used. In this system, earthing is most important. Here If some compromise or negligence for installation result, pay a lot of price .

Conclusion

This topic is not only a fact, it is true in our real world. Many such cases can be seen for this lightning strike.Lighting arresters are usually made of copper and cadmium separate earthing systems are used to operate lighting arresters. These earthing arrangements need to have low resistance and require regular maintenance.

Nowadays most building, offices, Mobile signal towers constructors always mind that this problem and take any prevention for making exclude this problem from system. If he has to count as much money.

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Bimetallic strip over heating protection and detection

2020-07-10T20:41:00.034+05:30

Why bimetallic strip use overheating protection not for use heat detection?

bimetallic strip over heating protection and detection [figure 1]

bimetallic strip over heating protection and detection [figure 2]

What is bimetallic strip

The bimetallic strip usually acts on the coefficient of Contraction and expansion of metal. In this case, two different metals are joined together by riveting or welding. We know different materials have different coefficients of expansion. An example of a bimetallic strip made of aluminum and steel . Expansion of aluminium is more than steel . Aluminum expansion per degree C is 24×10^-6 °C . and aluminum is 13 × 10^-6 °C. If applied heat the less expansion materials bend the whole strip. Using this function we can make any material heat effective or heat sensitive. This is the brief explanation of Bimetallic strips.

Application of Bimetallic strip

Sometimes it is used for over heat protection or heat detection .

Overheating protection Application

Geyser or water heater,Electric iron, Refrigerator,heater etc

Heat Detection

In the electrical control panel use a thermostat for detection of any fire Hazards . This thermostat is made of bimetallic strips.

How both metal join each other

Many ways to join Bimetal ,The two ends of the bimetal are riveted to join the two bimetals together.

In addition, laser welding spot welding is done by riveting the bimetal.

The most effective of these two riveting processes is laser welding spot welding.

Why bimetallic strip suitable for detection

When heat is applied, the metal that expands more and bends.When the heat is applied and stopped, the metal returns to its previous state.

Bimetallic strips are usually made of copper steel , steel brush, or aluminum and steel material. Depending on the nature of the metal and bimetallic strip, a device called a thermostat was created .

This device is used for overheating protection. This device is commonly used for heat control in geysers , washing machines ,refrigerators, tube light starters ,heaters and other heating applications. On the other hand, heat detection is done by a heat sensor. It must be used in school, college, office, hospital etc .

This can be said in terms of the question bimetallic strip operating temperature is 250°C or 482° F. This information proves that the fire will spread a lot as long as the bimetallic strip is sensed.For that it is not used in case of heat detection.

How bimetallic strip operate specified temperature

Here use a spring which can control the fixed point. When system need low temperature . The spring arrangement decreases the gap between the bimetallic strip and the fixed point. When system needs medium temperature the spring Increase the gap between bimetallic strip and fixed point more the required low temperature. Again when system need to operate higher temperature the release the spring then decrease the gap between bimetallic strip and fixed point on maximum position. Then higher heat will release. This arrangement is mostly use in electric iron ,geyser or water heater , electric kettle, etc application.

But electrical control panel maintain the gap between bimetallic strip and fixed point as low as possible. Because electrical hazards will be more dangerous than other hazards, fire will within a second take a turn that cannot be controllable. Here we use a temperature sensor as a supporting system . If any system malfunctioned then other system can detect the hazards.

Nowaday advance fire protection system

When any system tends to any fire Hazards . Here we need a minimum temperature for dictation. The bimetallic strip failed to operate at minimum temperature. When fire Hazards will excessive then the bimetallic strip will react. This is not an efficient way to fire detection.

Here many type of advanced electronic system and Sensor . This operation will be done in an efficient way. Here we can regulate the minimum react temperature value. And Control other prevention Equipments. Such as automatic water spray, fire extinguisher gas etc. The will finish when try to rise.

We already discussed this fire Hazards prevention sensors. Here some equipment is the direct temperature of the atmosphere . And some of them they are detect smoke.

So it is dangerous. Since the bimetallic strip operates at higher temperatures, it is suitable for use in temperature control. Temperature control works well with a bimetallic strip.

Usually the device that should be used for heat detection purposes needs to be highly sensitive.Sensors are used for heat detection. It continues to record the room temperature and provides an integrated signal to the output alarm circuit.

Generally speaking, it sends an alarm signal to the output when the temperature rises above the room temperature in a room and it continues to rise.

Heat sensors as well as smoke sensors are used to make the fire extinguisher system more sensitive.

Bimetallic strip use of power system

Bimetallic strip or thermostat use Electrical substation meny devices. We know in electrical substations heat rising means fault . Mainly it can use circuit breaker and Transformer. When Transformer leakage current is rising then that leakage current or leakage flux try to

Transformer wall or cabinet. Due to the interaction of leakage current heat can be developed in Transformer. And it can rising rapidly.

The cause of leakage current is any malfunction in core or winding or any failure of insulation. This rising temperature is dangerous for Transformer. Rising supply current is measured by many types of instruments but leakage current Detection does not have any equipment .

Due to rising leakage current heat will increase . We detect the Heat by thermostat . When this occurs, the thermostat send a trip signal to the panel room. The Transformer take shutdown for fault troubleshooting.

Same way when a circuit breaker trips, the circuit heat will develop. Then That heat does not make a huge fire hazard . Thermostat is use here.

The thermostat send a trip signal to panel room . Then change the supply through duplicate bus . And which circuit breaker detected rising temperature. That circuit breaker take to under maintenance.

Conclusion

Bimetallic strip efficiently work on overheating protection or temperature protection. So Nowday use advance heating protection system have some malfunction due compactness. Here Bimetallic strip is reliable for over heat protection with less price .

It means any over heat protection system Bimetallic strip is only way to reduce the price of protection system. bimetallic strip cannot improve a fire extinguishing system.For this bimetallic strip is not suitable for heat detection.

Conclusion

Bimetallic strip efficienctly work on over heating protection or temperature protection. So Nowday use advance heating protection system have some malfunction due compactness. Here Bimetallic strip is reliable for over heat protection with less price . It means any over heat protection system Bimetallic strip is only way to reduce the price of protection system. bimetallic strip cannot improve a fire extinguishing system.For this bimetallic strip is not suitable for heat detection.

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Alternating wave realization without Oscilloscope

2020-06-22T16:07:00.032+05:30

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incident lamp

Introduction

This is In this topic we will discuss two effects that will help to realize alternating wave.From these effects we get no result about the parameters of any alternating wave but we realize only the presence of alternating wave.Such effects are not used for any application. But This is an effect we can see from this Experiment.

We can not say that this is a useless application. Maybe invent some application where we can this this type of effects. This effect is only incident lamps or any tungsten lamps.

These are only taken as a theory.However, some of these theories have been used in emergency situations.Let's talk in detail about these effects .

We name two effects. First one is called the flickering effect and another one is the motoring effect in the Incandescent lamp.

Oscilloscope

Oscilloscopes show the Alternating wave amplitude Frequency . We can see Alternating waves with any modifications. What this experiment is about is whether it is possible to identify the alternating wave in any way other than the oscilloscope as a realization of the alternating wave.

Camera Flickering effect

At first we discuss camera flickering effect.This type occurs when a camera is used to take pictures or videos of an alternating current powered device.

What happens in this type of effect is that when a camera can take a picture of an alternating current powered device, some disturbance can be noticed.

This disturbance is seen as some parallel lines are seen rising from the bottom to the top. Which prevents you from taking pictures or videos.This usually happens for frequency and shutter speed.

We know that our standard frequencies depend countrywise. Which is 50 Hz in some countries and some is 60 Hz .Which means a 50 or 60 cycle is made in 1 second.

Which means in one word an alternating current power device is on and off 50 times or 60 times.

Which we cannot understand with the naked eye. But this effect can be seen through any camera. how the camera has made this possible is that the camera has a special setting called shutter speed.

When I take a video, a video is created by adding several images.And the objective of taking pictures with the camera is an alternating power device that is on or off 50 or 60 times in 1 second. Cameras try to take pictures of every millisecond or any instance.

Because the frequency of taking pictures is below the supply frequency. Camera tries to capture every cycle as a picture but it can fail. When adjust the shutter speed at 50 hz or 60 hz then not seen any flickering and none of shown lines below to top .

The camera's image capture then slows down, causing one image to rise above another, and for which we can see parallel lines.

Although some expensive cameras can control the shutter speed, some low priced cameras do not have this type of feature so this effect is a better understanding of all those cameras.Such experiments are done only to perceive the alternating wave.

Motoring effect

Another one is the motoring effect. Physically this effect is a theory of flaming motoring principle. Such effects are clearly understood in Incandescent lamps. We know that the incandescent lamp filament is made of tungsten.And this tungsten is in the form of a coil inside the lamp.

To understand this effect, we need a permanent magnet.When the permanent magnet is held on the glass wall near the lamp coil, a vibration is felt in the tungsten coil inside the lamp just like a dc motor .

A dc motor when it can connect in shunt .when dc supply apply to motor commutator make this dc supply as a Alternating current in rotor and stator still present Direct current . Stator behaves like a permanent magnet . When Alternating current Cuts the stator field a Torque will generate.

Here we assume the tungsten coil is a rotor and the permanent magnet is a stator . Due to the coil not having any Rotating arrangement so the tungsten coil fills with vibrations.

Some more information for vibration. Alternating current coil magnetic fields always change their poles . When the coil induces the North pole then attracts permanent magnet to the south pole. When the coil induces the South pole then attracts a permanent magnet North pole. Coil induced North pole then repelled permanent magnet North pole.Coil induced South pole then repelled permanent magnet South pole. This can happens again and again .

And the level of this vibration depends on the permanent magnetic flux density and flux intensity.Since the relative permeability of glass is much higher. In incident lamps have nitrogen gas for ionization. This nitrogen gas permeability is also included. This vibration is most noticeable when the flux intensity is much higher than that of the permanent magnet. Hence it is called Motoring effect.

Let's discuss why this kind of vibration happens. And to understand this, you must first know the motoring principle. When an alternating field is placed in a static field, those two fields create a motion.

The tungsten coil and the permanent magnet inside the lamp do exactly the same thing since the tungsten coils have a fixed point connected and the tungsten coil has no chance of rotation causing the tungsten coil to create a vibration.

Here we can use electromagnets of DC supply instead of permanent magnets but we cannot use electromagnets of alternating supply in any way. The reason is that this effect is understood only when the coil has a static magnetic field.

This type of effect refers to the perception of alternating waves . This type of effect cannot be used in any application, it is just an experiment. And a theory for identification of Alternating waves. This content conclusion says that prevention of the experiment or what you should need for this experiment observations.

Conclusion

Such experiments should not be done without the necessary materials. Without the materials for the experiment, the purpose of the experiment is not achieved and it can be harmful and have some fire Hazard issues .

Because this Experiment observation takes some time but the incident lamp starts heating . Without any holding arrangement this incident lamp burns your experiment surface. Arrange a proper working place. This experiment is good to go.

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Off-Grid Solar Power System Efficient And Economical view

2020-06-11T17:37:00.045+05:30

Off-Grid Solar Power system

Solar panels

Cover page

IV and PV CURVE

Introduction
Off Grid
Off Grid solar power System is which system that generates power not feeds to any Grid.
On Grid
On Grid solar power system is which system that generates power feeds a Grid.Some smart devices used in modern off-grid solar power system, which makes the solar power system much more efficient.

Because of the arrangement used in domestic modern solar power systems, the initial cost is comparatively low and the output power is regulated. The conventional old solar power system is not in these facilities therefore uneconomical.

Modern Solar Power Arrangements

Let's talk about how modern solar power systems have improved so much. This modern system is capable of using battery power as well as the power of the service main, capable of tracking the maximum power from PV panel output and efficiently regulating battery charging .

Mainly two smart devices used in this modern system: the first one is a maximum power point tracker with voltage regulator and another one smart inverter with charge sharing technique.

Let's discuss the first smart maximum power point tracker. Basically this one is a modern charge controller.First of all we will try to understand current voltage curve and power voltage curve in PV modules.

Photovoltaic cells
We give just brief information about photovoltaic cells. Photovoltaic cells work like bipolar junction diodes. In a PV cell made by two types of material P type material and another is N type material .

P type material Dropped by Trivalent impurity and N type material Dropped by Pentavalent impurity. In between two materials make a junction .

P type materials belongs positive charge electrons or Holes and N type material belongs negative charge electrons . So we know the heating effect of semiconductors And we need to know the definition of semiconductors , when such conditions make a conductor which is called a semi conductor.

The such condition is the heat from the sun 🌞. The density of electrons is huge in N type material, it helps to heat the electron flow through the circuit and neutralize in P type material . The flow of electrons through a circuit called current.

Types of PV module available in market
There are many PV module available in market but most three PV module is used commonly

1) Mono crystalline
2) Poly crystalline
3) thin film

Charge Controller
In the figure we see the IV curve over the PV curve in the PV module. In PV curve a maximum point is shown this is called maximum power point .The charge controller tracker is a microprocessor based module.

The tracker tracks the maximum power point of the PV panel as well as identifies the output of the PV panel and battery charge. Then sends a signal to the PWM module .

In the PWM module generate a pulse for control dc to dc converter or buck boost converter. The battery input voltage Maintained by the voltage regulator.

When the battery charging is full, the tracking device sends a signal to the breaker and the breaker will cut the supply. The function of the tracking in the microprocessor module will be done by algorithm. Most algorithms are used for tracking the maximum power.

The maximum power point in the PV panel depends on weather. When the weather is poor proportionally the output power is poor.

Then buck boost converter boost to the power and regulate output is provided for battery charging. This is the main advantage of this type of charge controller.

Inverter
Another, advanced inverter Generally inverter works to change the supply DC to AC. But this type of advanced inverter is mainly from battery and PV cell DC supply to AC supply.

But there is also another feature in inverter supply power to load with help of service main AC power; this is called smart charge sharing technique. How it works, let's see. When power from a PV cells or batteries is not enough to drive the load.

The rest of the inverter takes power from the service main. On other hand PV cell output power is not enough for battery charging then the inverter takes remaining power from the supply main.

If the user wants to drive total load by PV call at that time inverter charging the battery by service main till full charge but does not overcharge under any circumstances. This inverter makes the solar power system as uninterruptible as possible .
Economical view
Mono crystalline pv module is popular in the market for Efficiency .This type of PV module speciality is this module Generate electricity not depends on weather . It can give electricity Maximum of any weather. Due to this reason this module price is more than the polycrystalline pv module.

Polycrystalline pv module is less Efficient then mono .It can generate electricity depending on weather . It is most popular in domestic application for reducing the total installation cost .

Price low then other type of pv module available in market.Thin film it is efficient and it is transferable. It is most popular in E-bikes, E-van ,E-cars,Buses etc. It is looks like a paper.

Calculation of Install Off-Grid Solar Power system
Before the estimation we need the to know what is the approximate load when Off-Grid Solar Power system Install . Number of Pv module need and need to know range of battery and charge controller and other safety Equipments.
Load Calculation
Working Load is needed for Estimation . Load is directly proportional to Total cost. If you want to reduce your price . You must select the selective loads Or on the other hand you want an Off-Grid Solar Power system that can drive all loads that can reflect your total cost..
At first I added all the Loads . For proper understanding we use a example
Ceiling fan - 3nos ×75 watts =225 watts
LED LAMP - 2 nos×18 watts =36 watts
LED TUBE - 2 nos × 20 watts =40 watts
LED TV - 2 nos × 20 watts. =50 watts
Not Predetermined loads =49 watts
Total load =400 watts
Inverter Selection
Our total load is 400 watts
For safety Reason selected inverter is 300% above the total load. It can depends upon the what Inverter available in market . But This case we choose inverter between 800 watts -1 kw.
Required Current
Total. Load is 400 kw
And battery voltage is 12 v
Required Current is =400/12= 33 A
Battery AH Selection
For 400 watt load and backup time 6 hours and battery volt 12 v
The Required AH is = (400×6 )/12 = 200 AH
But the market Available Amp-hour battery is 150 AH and 220 AH . So here this case 220 AH battery is preferable.
But here you backup more than you need to another battery which is connected with a series with the present battery.
Normal Battery charging current
Well and safe battery charging current 10% of total capacity of battery. Here in this case 200AH battery capacity and the charging current is 20 A.
Here you will set the inverter 20 A as an output.
PV module required
Various types of Pv module is available in the market . They are different wattage and voltage . Our battery voltage is 12 volt . We recommend using a 150 watt PV module or 180 Watt PV module Mono crystalline.
Our total current requirement is total battery charging current and total required load current is about 53 A
And total wattage required is 12×53= 636 watt.
This wattage helps to choose solar panels. If you use 150 watt Solar panel then required 636/150= 4.24 or 5
If you use 180 then the required solar panels are 4 .

Minimum Estimation of Solar Power If Install at Home
In this point we give an example for installing a pv module at home . If you calculate this way you can find your estimation.
This Estimation is our Example load (400 watt)
5 solar panel price is =5500 Rs ×5 =27500/-
( 5500 is approx value for 1 solar panels ,it will varies manufacturing companies)

Inverter 1000 watts = 5100/- (approx)
battery 220AH = 15700/- (approx)
12 volt charge controller =700/- (approx)
Required wires= 4000/- (approx)
Installation Frame = 7000/- (approx)
Total Expenditure = 53,000/- ( maximum)

Conclusion
If the user wants to reduce installation cost then the user can install a solar panel with a lower power rating than the rated power required for driving load.

such advanced solar power systems have become widely popular in homes, offices, schools and colleges.

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Slip ring induction motor and double cage induction motor

2020-06-06T01:28:00.029+05:30

slip ring induction motor and double cage induction motor [figure 1]

Induction Motor

Induction motor is very popular in industrial applications and also traction . Popularity of induction motors is reliability. We know 85% of our system works on AC supply . AC is also always available this tis the main advantage of Induction Motor.

3 phase Induction Motor works on the basis of principle electromagnetic induction.we brief some working principle of induction motor. We know induction motors have two parts: stator and rotor. Stator can make rotation magnetic field which can induce rotor coil . Rotor coil generates emf at the resulting flow current through the coil and the coil can fill a magnetomotive force .

That magnetomotive force sometimes attracts each other or repulses each other. It is not over yet because we need to know how a rotating magnetic field is made in a stator . Because we have 3 phase power supply and we know between phases have some Electrical 120° angle Difference.

It means stator when a coil made mmf then 120° apart another coil made mmf . When the first coil attracts the rotor pole the other coil repulsed Rotor pole. This can continue again. Torque is created for this event.

Types of Induction Motor

Constructionaly Induction Motor is two types

1) Slip Ring Induction Motor

II) Squirrel Cage Induction Motor

Slip Ring Induction Motor

The Rotor of Slip ring Induction motor Short circuited by Slip ring and brush . With brush a external Resistance is Installed for speed control this called rotor resistance speed control.

The external Resistance helps to make starting torque with low starting current . The Constructionaly length of the slip ring Induction motor is less than the Squirrel cage Induction Motor. Copper loss is high . efficiency is low compared to Squirrel cage Induction Motor.

It uses high torque required applications such as drilling machines , punch machines etc.

Advantages

> High Starting Torque

> low starting current

> Rotor resistance speed control

Disadvantages

> Market price is High

> Required regular maintenance

> Using the slip ring brushes causes High sparking problem

Squirrel cage Induction Motor

The Rotor of Squirrel cage Induction Motor is short circuit by ending ring . This type of Rotor not support any external Resistance it means . We can not control speed by external Resistance. Squirrel cage induction motor speed control only controls voltage , frequency and changing the poles .

But all speed control method most economical and popular speed control is Voltage and frequency control by Variable Frequency Drive (VFD). Variable frequency control provide precious speed control . The squirrel cage Induction Motor is Copper loss is low and High efficiency . And starting current is high due to low starting torque .

This type of motor use exhaust fan low starting torque required application. The Economical value of Squirrel cage Induction Motor is very cheap Compared to the slip ring induction motor.

The Squirrel cage Induction Motor Rotor slot is skewed because of good magnetic interlocking. If Squirrel cage Induction motor use For heavy load . Then the induction motor rotor uses a double Squirrel cage for better magnetic interlocking.

Advantages

> Less maintenance required.

> Market price is very cheap.

Disadvantages

>Low starting torque .

>Rotor resistance speed control not available.

Double Squirrel cage Induction Motor

Double Squirrel cage Induction Motor is also similar Squirrel cage motor . But the Difference is that it is use for high Starting Torque purpose like a slip ring Induction motor. Here have a two Squirrel cage and both cage are short circuited by end ring .

Constructionally two type Squirrel cages are used, the inner Squirrel cage and outer square cage . Outer cage made by brush material or aluminum for made high resistive and inner cage made by copper for made low resistive.

Main aim of increasing starting torque of any type of Rotor can use either it's slip ring type or Squirrel cage or double cage is low current because low current proportional to low speed and high Torque . That will be see Speed torque characteristics of induction motor .

Double cage Induction Motor outer cage is highly resistive when stator flux cuts first outer cage then inner cage and due to low resistance the starting torque of double cage induction motor is increasing.

If we consider outer cage and inner cage a parallel resistance so the equivalent resistance is not too low or not too high . So the induced current is similar to a slip ring.

The basis of this theory is that a double cage induction motor must have a high Starting Torque and low starting current induction motor .

Advantages

> Cheap price compared with slip ring induction motors.

>Less maintenance.

> High Starting Torque with low current.

Disadvantages

> Loss is compared to other types is huge

>Power factor is high.

Can we use a double cage induction motor instead of a slip ring induction motor?

Answer is yes . Sometimes a double cage induction motor is an alternative to the slip ring induction motor . And about speed control , if we change the frequency of double cage Induction Motor Speed can control.

*Note

[Let's discuss the topic of two kinds of motor first, one slip ring type induction motor and another one double cage type induction motor.

Mainly the similarity of both kinds of Motor is torque and speed, basically both motors are constant speed motor and high starting torque.

We know motors are mainly determined by motor torque , speed and speed control. So the first two specifications are the same for both kinds of motor. Now the question is speed control , in general the induction motor is a constant speed motor.

But we can use voltage , frequency and rotor resistance for speed control. In slip ring induction motor speed control by rotor resistance and double cage type induction motor speed control possible by variation of frequency with VFD (variable frequency drive).

Here another contract is Double cage induction motor starting current is 4 to 6 times full load current and slip ring induction motor starting current is twice of load current.

This arrangement must follow the protection system of the Motor due to starting current. This backup arrangement is appropriate from financial point of view and the work situation point of view. ]

Conclusion

This management can be used until a new replacement arrives. This temporary backup system is very much helpful for factory production. From a production point of view the extra money for replacement is negligible. So, this arrangement is full proof economical..

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Can a DC Generator utilise Wastage Energy in a Traction System

Can a DC Generator utilise Wastage Energy in a Traction SystemIntroduction

Can a DC Generator utilise Wastage Energy in a Traction System

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Homemade Accurate Pulse Oximeter

Homemade Accurate Pulse OximeterPulse Oximeter

Pulse Oximeter

Introduction

Required Devices

In This project we need Only two item first one any Microprocessor (Such as Arduino UNO, Arduino Nano, Arduino mega etc ) and last one A well priced Pulse Oximeter sensor and some jumper wire.

It is very economical project because normal Marketise Pulse Oximeter price all around 2000/- to 2500/- . Our project cost only all done 1000/- to 1500/-. Download the Arduino exe file on your computer.

just uploading the code which is mentioned below . And connect the Arduino with the sensor just like the circuit diagram which is mentioned below .

If any problem of understanding just continue reading with the circuit description.

Project Description

Result

Google weather data compare with DHT11 Sensor data

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Google Weather

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Arduino setup

Experimental data

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IOT Based Smart Ceiling Fan working

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