A Turn-to-Turn Fault Detection and Inter-Windings Identification Scheme for EHV MCSR

This paper presents a new protection scheme for detecting turn-to-turn faults (T2TF) in extra-high voltage (EHV) magnetically controlled shunt reactor (MCSR) along with identifying the faulty-winding. The scheme is based on the angle of negative-sequence voltage (∠3V
₂
), and the magnitude of negative-sequence current (|3I
₂
|) measured through potential transformer (PT) and current transformer (CT) at EHV bus and the terminal side of the reactor, respectively. The main objective of this scheme is detecting low-level T2TFs especially, from 1 to 4% shorted turns of power winding (PW), control winding (CtrW), compensation winding (CpW) and, simultaneously identifying the faulty-winding among them. The performance of the proposed protection scheme is evaluated through intensive simulations on MATLAB/ Simulink-based simulation model and authenticated the ability of the scheme for differentiating T2TFs from energization, normal operation, and external faults. The scheme is tested during MCSR energization, and its power regulation scenarios during steady-state operation. The results obtained validate the effectiveness of the proposed protection scheme.