A controllable reactor for reactive power compensation of electrified railways

A novel controllable reactor is proposed to regulate reactive power of traction substations automatically according to dynamic loading by paralleled with fixed capacitors. This controllable reactor which has multiple second windings connected with anti-parallel thyristors and voltage-source inverter (VSI) respectively, can obtain reactance varying in a wide range continuously by step-switching the thyristors and controlling VSI current, so that implement reactive power adjustment. Simulating and experimental results validate the advantages of the presented reactor such as fast response speed, high compensating precision and low harmonic output et al.