交直交牵引变电所用单相整流器研究与设计

Research and Design for Single-phase Rectifier in AC/DC/AC Traction Substation

提出一种三相对称型交直交牵引变电所主电路拓扑,用以解决电气化铁路中由于牵引负荷单相性和非线性导致的的谐波、无功和负序等一系列电能质量问题和电分相问题。针对输入侧多重化结构中单相脉宽调制(PWM)整流器传统双环控制策略在冲击性负荷下存在控制精度不高,鲁棒性不强的缺陷,提出基于比例积分(PI)和准比例谐振(QPR)复合控制器的改进控制策略,提高了网侧电流的响应速度及跟踪性能。此外,在控制系统中加入负载电流前馈环节,提高了系统对于冲击性负荷的抗扰性能,增强了系统的鲁棒性。对电压环和电流环及负载电流前馈环节进行设计,并给出主电路关键参数的计算方法及功率器件选型。最后进行了实验验证。

A three-phase symmetric main circuit topology of AC/DC/AC traction substation is proposed to solve a series of power quality problems and phase separation problems such as harmonic,reactive power and negative sequence caused by single-phase and nonlinear traction load in electrified railways.In view of the defects of the traditional dualloop control strategy of single-phase pulse width modulaiton(PWM)rectifier at the input side multiple structure,the control precision and robustness are not high under the impact load.An improved control strategy based on proportional integral(PI)and quasi proportional resonant(QPR)composite controller is proposed to improve response speed and tracking performance of source current.In addition,the load current feed-forward link is added to the control system,which improves the system disturbance rejection performance to impact load and enhances the robustness of the system.The voltage loop,current loop and load current feedforward link are designed,and calculation method of key parameters of main circuit and the selection of power devices are given.Finally,the experimental verification is carried out.