Switching Transients and Ferroresonance in the Power System

Abstract

Over the last decade, power disturbances have become an important factor in electrical networks. It is worth mentioning switching transients and ferroresonance in the network. Ferroresonance is a special case of resonance involving non-linear inductances that mainly affects the functionality of transformers and it is originate from the switching transients. Little is known about this complex phenomenon as it is rare and cannot be analyzed or predicted by the computation methods. It's analysis is done by computer simulations.

Switching transients and ferroresonance phenomena were simulated in PSCAD software to study its effect. Simulation of Switching transients with Energization of transmission line, with and without trapped charges, analyze TRV/RRRV for fault conditions and inductive current switching overvoltage to check this overvoltages are within BIL limits or not with as per standards.

Another case of ferroresonance is simulated with single phase switching and with grading capacitance of circuit breakers. This simulation also include ferroresonance overvoltage mitigation with the help of reactor connected in tertiary winding. Also, simulated a real case of traction system where the potential transformers were failed because of overcoltages due to ferroresonance.