Negative-sequence current compensation of power quality compensator for high-speed electric railway

In order to solve the power quality problem of high-speed electrified railway at 350km/h, this paper presents a new type of power quality compensation system, which is mainly made of railway regulator RPC, two sets of thyristor-controlled reactor and two sets of thyristor-controlled 3^rd filter. The RPC is only used to transfer active power. The thyristor-controlled 3^rd filters are used to suppress 3^rd harmonic current and change the phase angle of power supply current. The thyristor-controlled reactors are as the same used to change the phase angle of power supply current. The proposed power quality compensator has small capacity and low cost. The working principle of negative sequence current compensation of the proposed power quality compensator is analysis. The simulation results have verified the correctness of the theoretical analysis in this paper, and the proposed power quality compensation system can reduce the capacity of the active part and have a good performance at negative sequence compensation.