Metal Oxide Surge Arrester

Definition: The arrester which uses zinc oxide semiconductor as a resistor material, such type of arrester is known as a metal oxide surge arrester or ZnO Diverter. This arrester provides protection against all types of AC and DC over voltages. It is mainly used for overvoltage protection at all voltage levels in a power system.…

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Overhead Ground Wire or Earth Wire

Definition: The overhead earth wire or ground wire is the form of lightning protection using a conductor or conductors. It is attached from support to support above the transmission line and well grounded at regular interval. The earth wire intercepts the direct lightning strikes, which would strike the phase conductors. The ground wire has no effect…

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Switchgear

Definition: The apparatus used for controlling, regulating and switching on or off the electrical circuit in the electrical power system is known as switchgear.The switches, fuses, circuit breaker, isolator, relays, current and potential transformer, indicating instrument, lightning arresters and control panels are examples of the switchgear devices. The switchgear system is directly linked to the supply…

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Electrical Substation

Definition: The electrical substation is the part of a power system in which the voltage is transformed from high to low or low to high for transmission, distribution, transformation and switching. The power transformer, circuit breaker, bus-bar, insulator, lightning arrester are the main components of an electrical substation. Single Line Diagram of an Electrical Substation…

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Induction Voltage Regulators

Definition: The induction voltage regulator is a type of an electrical machine in which the output voltage may be varied from zero to a certain maximum value depending upon the ratio of turns in the primary and secondary windings.The primary winding is connected to the circuit which is to be regulated, and secondary is connected…

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Motor Protection Scheme

The various types of the protective relays are available for protecting the motor from faults. These relays sense the abnormal operating condition and make the circuit breaker to trip. The motors provide protection against faults in windings and associated circuits, excessive overload and short circuits, under voltages, phase unbalances and single phasing, phase reversal and…

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Induction Motor Protection System

The circuit diagram of the three-phase induction motors is shown in the figure below. Magnetic contactor starter essentially consists of a set of start and stop push buttons with associated contacts, overload and underload protective devices.The start push button is a momentary contact switch that is held normally open by a spring. The stop push…

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Feeder Protection

Definition: Feeder protection is defined as the protection of the feeder from the fault so that the power grid continue supply the energy. The feeder injects the electrical energy from the substation to the load end. So it is essential to protect the feeder from the various type of fault. The main requirement of the…

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Carrier Current Protection of Transmission Lines

Carrier current protection scheme is mainly used for the protection of the long transmission line. In the carrier, current protection schemes, the phase angle of the current at the two phases of the line are compared instead of the actual current. And then the phase angle of the line decides whether the fault is internal…

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Types of Lightning Arresters

The lightning arrester protects the electrical equipment from lightning. It is placed very near to the equipment and when the lightning occurs the arrester diverts the high voltage wave of lightning to the ground. The selection of arrester depends on the various factors like voltage, current, reliability, etc. The lightning arrestor is mainly classified into…

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