MGVCL Exam Paper (30-07-2021 Shift 2)
The expression for voltage regulation of a short transmission line for leading power factor is given by: ____, where, 'I' is the line current, 'V_r' is the receiving end voltage, 'R' is the line resitance and 'X' is the line reactance.
For lagging power factor = (IR*cosφ + IXsinφ)/V_r For leading power factor = (IR*cosφ - IXsinφ)/V_r Zero voltage regulation occurs on leading power factor only.
The capacity of reactor = 50 MVAr when it is operated at 415 kV. Impedance of reactor = V2/MVAr = (415*415)2/50 = 3444.5 Ω For 400 kV, Reactive power observed = (400*400)/3444.5 = 46.45 MVAR
Or
VAr capacity of capacitor or reactor is proportional to V²
Equivalent resistance of the circuit, Req = (12||18) + 8 Req = 7.2 + 8 Req = 15.2 ohm Source current = current through 8 ohm resistor, I = Vr/R8 I = 20/8 I = 2.5 A Supply votage V = I*Req V = 2.5*15.2 V = 38 V
MCCB stands for Moulded Case Circuit Breaker. MCB stands for Miniature Circuit Breaker. ELCB stands for Earth Leakage Circuit Breaker RCCB stands for Residual Current Circuit Breaker.
EXAMIANS