Research On High-speed Rail Power Quality Control Technology

In the global economy promoting low-carbon green pattern background, electrifiedrailway because of its unique environmental conservation and economic characteristics,becomes a "green transport" internationally. High-speed passenger rail which is moresecure, efficient and comfortable receives high priority by many countries, and get acomprehensive rapid development in China. As the high-speed railway is a single-phasepower supply system, and generally ac drive, high-speed rail operators will bring negativesequence harmonics and other power quality problems, seriously affecting the stableoperation of the power system, and therefore it is necessary to take effective power qualitycontrol measures.This paper analyzes a variety of commonly used traction transformer and thenegative sequence current imbalance. Our high-speed railway choose to use more of V/vwiring transformers, and according to its electrical characteristics, this paper proposes acomprehensive package used in traction power supply system based on RPC for negativesequence, reactive and harmonic compensation, and analysis of its negative sequence,reactive and harmonic current compensation principles. Then analyzes the negativesequence, reactive and harmonic current detection method and proposes sliding windowiterative algorithm based on instantaneous phase DFT principles and improve the voltagecontrol strategy. Then proposed a three-phase STATCOM structure which can reduce twogroups switching devices and effectively reduces the capacity of the device but does notaffect the compensation effect.Finally, using the matlab software, simulation study of the effect of reactive powercompensation for the two negative sequence, reactive and harmonic compensation devicesverified harmonic suppression, negative sequence compensation and comprehensivecompensation ability each. Simulation results show that the two power compensationdevice can the reasonable regulation of active power and reactive power compensationeliminating the three-phase negative sequence current when two-phase power of the armsis not equal in power grids. The compensation devices in high-speed rail traction powerstation can compensate the two arms active and reactive power, but also can effectivelyfilter out the harmonic current in the two arms of traction power supply. So it can reach the purpose of a comprehensive compensation chnology.