Turn-to-Turn Faults Analysis of an Extra-High Voltage Magnetically Controlled Shunt Reactor

This paper analyzes the realization of turn-to- turn fault (T2TF) in a simulation model of an extra-high voltage (EHV) magnetically controlled shunt reactor (MCSR). The three-phase MCSR core in MATLAB/Simulink-based model is built from the multi-winding transformer block. This block only allows taps on its upper-left or upper-right winding at the same time. Each single-phase of an EHV MCSR has three-windings, power winding (PW), control winding (CtrW), and compensation winding (CpW). These windings are positioned as upper-left winding, i.e., PW, upper-right winding, i.e., CtrW, and lower-right winding, i.e., CpW. To apply T2TF, tappings can be taken only on upper-left or upper-right winding at the same time. To analyze CpWT 2TF, the respective positions of the windings should be changed, due to the limitation of the model. Moreover, by changing the windings position or taking tappings from any side of the multi-winding transformer block, several parameters of the model experience changes. Based on these facts, a comprehensive analysis of each winding T2TF is performed. This study reveals several important aspects of an EHV MCSR T2TFs, before modeling and designing a proper protection scheme for each winding.