Research On Power Quality Control Technology For Electric Railway Power Network Based On SVG

Electrified Railway received a fast development in recent years as it is the major of railway. At the same time the pollution of Electrified Railway increased serious, such as harmonic, reactive negative and voltage sag. Harmonic, reactive power and voltage sag of traction power supply system would be more prominent with the level of improvement railway electrification continuously in the future. Therefore, it’s important to improve the power environment and improve the electrical management that study the harmonic of comprehensive management for power supply system of electric traction, reactive power and voltage drop. The paper introduced power quality problems and the possible harm of traction power supply system and analyzed the control method of power quality problems. The paper presents a scheme for Comprehensive control of power quality of electrified railway traction based on SVG.Firstly, this paper analyzes the dynamic reactive power compensation principle, basic structure, voltage control strategy and current control strategy of SVG which is used for Electrified Railways, optimized the main circuit, control strategy and trigger pulse modulation strategy of SVG, designed two compensation of single phase SVG; secondly, this paper introduced the compensation principle and designed the control method of SVG when the traction is in abnormal condition in order to realize function of SVG to compensate the connection node voltage; then, in view of complex conditions, power quality fluctuate larger and more frequent, this paper gave a concrete scheme of governance in the vicinity of the station, designed and selection the compensation capacity and parameters of the program; finally, build the simulation model of system in MATLAB, simulated and analyzed effect of the compensation scheme. Simulation results show that the integrated control scheme which was designed in this paper can well realize the comprehensive management of reactive power compensation, harmonic suppression and voltage sags in traction network. It can provide the reference for controlling power quality of Electric Railway in the future.