Principle of DOL starter: A Direct-On-Line (DOL) starter is an electronic 3-phase  control framework which offers delicate begins in DELTA conneection. DOL starters are presently replacing the utilization of manual or semi automatic "star-delta" starters. In the  beginning of a 3-Phase Induction motor, full line voltages are connected to the motor through contactors. The DOL is these days the most widely recognized sort of 3-Phase starter...

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Starters for Three Phase Induction Motors

Starters for Three Phase Induction Motors: There are  many types of starters used for starting three phase induction motors depending upon size of motor and the work for which motor is used. Starter selection also depend upon construction of the motor. due to advancement in electronic control, electronic starters are also very famous now a days. process type and working conditions are also considered in starter selection. There are basically...

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PROTECTION OF THE GENERATOR DUE TO UNBALANCE LOADING:

PROTECTION OF THE GENERATOR DUE TO UNBALANCE LOADING: Because of fault there is an imbalance in the three phase stator currents and because of these irregularity flows, twofold frequency currents are impelled in the rotor center. This reasons the over warming of the rotor and therefore the rotor harm. Uneven stator currents likewise harm the stator. Negative sequence relay furnished with the over current relay is utilized for the assurance...

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Over/Under voltage Protection:

 Over voltage Protection:  Over voltage happens in light of the increment in the speed of the prime mover because of sudden loss in the burden on the generator. Generator over voltage does not happen in the turbo generator in light of the fact that the control governors of the turbo generators are extremely touchy to the speed variety. Anyway the over voltage insurance is needed for the hydro generator or gas turbine generators. The...

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UNDER/OVER FREQUENCY PROTECTION:

UNDER/OVER FREQUENCY PROTECTION: Over frequency results from the excess generation and it can easily be corrected by reduction in the power outputs with the help of the governor or manual control.  Under frequency operation: Under frequency occurs due to the excess. During an overload, generation capability of the generator increases and reduction in frequency occurs. The power system survives only if we drop the load so that the generator...

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Generation of sinusoidal voltage

 Generation of sinusoidal voltage:  There are two facts that the voltage developed in a coil of a generator changes; the first one is it changes in magnitude from instant to instant as varying values of flux are cut per second and the other one is it changes in direction as coil side change positions under north and south poles, implies that alternating emf is generated. This means that the voltage is maximum as...

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