GATE 2022 : Electrical Machine Quiz 8

The single-phase reluctance machine can be made to work as a generator when mechanical power is supplied to the shaft. This is possible when

A 10 KVA, 400 V, 3 phase, star connected synchronous generator has an armature resistance of 0.8 Ω per phase and synchronous reactance of 1.5 Ω per phase. The voltage regulation at a power factor 0.6 lagging is _______.

An industrial load with load impedance of (3 + j4) Ω/phase, drawing the power from 3-ϕ supply. The voltage per phase is 230 V. A synchronous condenser is connected to improve the power factor to unity power factor. Then magnitude of per phase current drawn by the motor.

A synchronous generator is running over excited with R_f = 1.4 pu. This machine with a synchronous reactance of 1.20 pu is delivering a synchronous power of 0.5 pu to the bus. If prime mover torque is increased by 1%, then change in reactive power is:

A 3- phase salient pole synchronous generator has a terminal voltage/Ph of 230 V and delivers a phase current of 20A at 0.8 pf lagging. If the load angle is 20 electrical; the currents I_d and I_q are, respectively (in amp).

A 500 MVA, 20 kV, 50 Hz generator is supplying purely resistive load of 400 MW at 20 kV with X_d″ = 0.2 p.u. If all the three phase of the load are short circuited simultaneously, magnitude of initial symmetrical current in generator is ______ A . Consider load is directly across generator terminal.