A Thyristor Controlled Neutral Grounding Reactor for Medium Voltage Power Networks

An auto-regulated arc-extinguishing reactor (AER) was proposed in this paper. This AER has an autotransformer structure, whose primary winding acts as a main reactor, whose common winding and tertiary winding exert regulating functions. The common winding connects thyristor switched capacitors and performs gross regulating function. The tertiary winding is designed to have high leakage reactance with the main winding. The leakage reactance is controlled with a thyristors to exert a fine regulating. The AER operate at far away from resonant state in power system normal situation. When line to ground fault occurs, the AER regulates its parameters automatically and rapidly to achieve resonance with the network. The operation, the parameter determination, and the control scenarios of the AER are depicted in this paper. The proposed AERs are with advantages as large-scale continuous adjustability, low harmonics, superior linearity, and superior compensating effects