MGVCL Exam Paper (30-07-2021 Shift 2)
A delta-connected balanced three-phase load is supplied from a three-phase, 400 V supply. The line current is 20 A and the power taken by the load is 10 kW. Find the power factor.
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
The main function of an interposing CT is to balance the currents supplied to the relay where there would be an imbalance due to the ratios of the main CTs. Interposing CTs are equipment with a ratio that can be selected by the user to achieve the balance required. An interposing CT is installed between the secondary winding of the main CT and relay.
EXAMIANS