Oscillatory transient is the a sudden, non power frequency change in the steady state condition of voltage or current that is bidirectional in polarity.
When different types of consumers are charged at different uniform per unit rates, it is said to be Flat Rate Tariff. In this type, the consumers are grouped into different classes. Each class is charged at different uniform rate.
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