基于级联H桥结构的电气化铁路用SVG的研究

A Research on Cascaded H-bridge SVG Suitable for Electrified Railway

在对电气化铁路牵引供电系统的供电等级、结构以及电力机车负载的特性分析的基础上设计了适用于电气化铁路的SVG。提出了采用H桥级联结构来增大容量使其适用于电气化铁路牵引网以及适用与H桥级联结构的调制策略——载波移相脉宽调制技术;并设计了电流补偿和电压补偿两种补偿模式,使SVG在系统供电电压稳定时进行无功补偿和谐波抑制,而在系统发生电压跌落时转换为维持接入点电压稳定的电压补偿模式。并在MATLAB环境下建立了仿真模型,对设计的SVG系统进行了仿真分析。仿真结果表明设计的复合控制装置具有响应速度快、动态性能良好。

On the basis of the analysis of the power supply grade, structure and characteristics of electric locomotive load of the traction power supply system of electrified railway, this paper presents a design of an SVG suitable for electrified railways. It proposes the adoption of the H-bridge cascaded structure to increase the capacity so as to make the system suitable for the electrified railway traction network and for the modulation strategy of the H-bridge cascaded structure-the carrier phase shift PWM. Two compensation modes （ current compensation and voltage compensation ） are designed to enable the SVG to provide reactive compensation and harmonic suppression during stable power supply and voltage compensation in case of system voltage drop so as to maintain stable voltage at the access point. A simulation model is established in the Matlab environment and simulation analysis is made of the designed SVG system. The simulation results show that the designed composite control device has quick response speed and good dynamic performance.