Effect of series reactors on circuit breaker transient recovery voltages

Series reactors are applied in power systems to limit fault current magnitudes, to achieve load sharing between parallel circuits and to limit inrush currents associated with shunt capacitor bank switching. The reactors are often dry-type with low inherent capacitance and, if no remedial measures are applied such as the addition of capacitance, will add a fast rising component to the transient recovery voltages (TRVs) seen by the station circuit breakers. The paper describes how the reactor-affected TRVs can be calculated using a basic RLC circuit approach and the principle of superposition.