Study Of Three-phase SVC In Power Quality Comprehensive Management For Electrified Railway

In the background of the high speed of China’s economic development, the paceof the construction of electrified railway, especially high-speed railway is gettingfaster. And in the area of electrified railway, these trends---the larger traction load，the faster change of traction load, and the bigger capacity of traction substation havecaused many problems of electric power quality which become increasingly urgent. Asthe users of public power grid are increasingly demanding higher power quality， thepower quality comprehensive management of electrified railway attracts more andmore attentions.This paper analyzes the impact of power quality on the electrified railway topower system, and discusses the power factor, harmonics and negative sequenceproblem in detail. This article discusses the limitations of electrified railway powerquality management program in the past, and proposes the electric railway powerquality comprehensive treatment program.To solve the power factor, harmonic and negative sequence problems brought byelectrified railway, a set of new program for power quality was proposed. This programis different from the domestic two-phase SVC and the three-phase SVC accessed totraction substation high-voltage side. The program based on the three-phase static varcompensator (SVC) accesses to the low-voltage side of the traction substation, whichfocus on compensating the reactive power, harmonic and negative sequence.Meanwhile, the compensation admittance network is divided into both positivesequence and negative sequence compensation network, with the independent controlof positive, negative sequence network and overall compensation strategy.The proposed scheme of three-phase SVC compensator in electric railway powerquality management for power quality control is tested in MATLAB using toolbox ofSimPowerSystems. The simulation results show that this scheme can effectivelycompensate reactive power, restrain the harmonic and negative sequence，and achievethe related power quality national standards.