In a power network, 400 kV is recorded at a 415 kV bus. A 50 MVAR, 415 kV shunt reactor is connected to the bus. What is the reactive power absorbed by the shunt reactor?

• A. 56.45 MVAR
• B. 46.45 MVAR
• C. 76.45 MVAR
• D. 66.45 MVAR

Answer: (B)

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