Hydro Power Plants

Switch Yard Equipment

2013-04-11T21:08:00.003-07:00

Substation- Introduction An electrical substation is a subsidiary station of an electricity generation, transmission and distribution system where voltage is transformed from high to low or the reverse using transformers. Electric power may flow through several substations between generating plant and consumer, and may be changed in voltage in several steps. Circuit breaker The circuit

Cooling System of Power transformer

2012-06-08T01:23:00.002-07:00

Cooling System The cooling of transformers differs from that of rotary machinery in that there is no inherent relative rotation to assist in the circulation of ventilating air. The losses are comparatively small, and the problem of cooling can in most cases be solved by reliance on natural self-ventilation. Simple Cooling AN: Natural cooling by atmospheric

Types of Underground transmission lines

2011-11-06T08:18:00.000-08:00

Types of Underground transmission lines 1. High Pressure Fluid Filled pipe type (HPFF)- The conductor and its wrappings are often referred to as “cables.” The cables are surrounded by a dielectric oil that is maintained at 200 pounds per square inch (psi). This fluid acts as an insulator 2. High Pressure Gas Filled pipe type (HPGF)- Instead of a dielectric fluid, pressurized nitrogen gas

Operation of Current Transformers

2011-10-28T20:57:00.000-07:00

Current TransformersThe primary of a current transformer typically has only one turn. This is not really a turn or wrap around the core but just a conductor or bus going through the “window.” The primary never has more than a very few turns, while the secondary may have a great many turns, depending upon how much the current must be stepped down. In most cases, the primary of a current

GROUNDING SYSTEM

2011-10-26T20:59:00.000-07:00

IntroductionProper grounding system will assure the safety of people and protection of equipments at faults. In large electrical system like power house or a substation has a grounding mesh instead of a single conductor. Ground Potential Rise (GPR) The substation earth provides the connection to earth at zero potential. But at fault conditions potential of the grounding mesh rises due

SUPERVISORY CONTROL AND DATA ACQUISITION SYSTEM (SCADA)

2011-10-22T21:08:00.000-07:00

Introduction to SUPERVISORY CONTROL AND DATA ACQUISITION SYSTEM (SCADA)SCADA refers to a system that collects data from various sensors at a plant or in otherremote locations and then sends this data to a central computer which then manages andcontrols the data. There are two elements in SCADA application such as the process orsystem want to monitor and

PROTECTIVE RELAYS

2011-10-11T05:54:00.000-07:00

PROTECTIVE RELAYS IntroductionA protective relay is a device that detects the fault and initiates the operation of the circuitbreaker to isolate the defective element from the rest of the system. Most of the relays inservice on power system today operate on principle of electromagnetic attraction orelectromagnetic induction. Regardless of the principle involved, relays

Voltage transformer

2011-09-23T00:46:00.000-07:00

Voltage transformer A voltage transformer (VT) is a transformer used in power systems to step-down extra highvoltage and provide low voltage either for measurement or to operate a protective relay. 1. Inductive Voltage Transformer (IVT) 2. Capacitor Voltage Transformer (CVT) Accuracy Class Designation Measuring Voltage Transformers The accuracy class is designated by the highest

Disconnecting switch , Earthing Switch

2011-09-20T18:43:00.000-07:00

Disconnecting switchDisconnect switches are used to isolate a component of an electrical system from the power source. Electrical power distribution systems require switching for many reasons, including fault isolation, transfer loads from one source to another, isolation of line segments for purpose of maintenance, and in some instances for shedding loads.1.

Gas Circuit Breaker (GCB) - Continue

2011-09-16T19:49:00.000-07:00

Current interruption in a high-voltage circuit-breaker is obtained by separating two contacts in a medium, such as SF6, having excellent dielectric and arc quenching properties. After contact separation, current is carried through an arc and is interruptedwhen this arc is cooled by a gas blast of sufficient intensity. Gas blast applied on the arc must be able to

AVR Automatic Voltage Regulator

2011-09-13T07:29:00.000-07:00

Generator ControlAutomatic Voltage Regulator (AVR) is the main controller of the Generator.AVR has the control over the Excitation System.Voltage RegulatorThe voltage regulator are composed of automatic voltage regulator(AVR), manual voltageregulator (MEC) and over current limiter(OCL).Automatic voltage regulator (AVR)An automatic voltage control device "senses" changes in output voltage

SURGE ARRESTER- Introduction

2011-09-10T07:11:00.000-07:00