电阻制动斩波器控制策略的仿真

Simulation of Control Strategy for Resistive Braking Chopper

机车处于电阻制动工况时,为保证中间环节直流电压不超过允许工作电压,必须对置于中间环节的电阻制动斩波器进行控制。传统上是采用滞环比较控制策略进行控制,但该控制方法中的IGBT的开关频率一般不会固定,如果IGBT的开关频率不固定,极有可能导致检测电压中混杂具有较宽的频谱范围的谐波,这样会增加检测电压中滤波器设计的难度,这一点是滞环比较控制方法较为局限的地方。本文分析对比了PI控制、前馈+PI控制和直接占空比控制三种控制策略的优缺点,结合仿真和现场经验,提出直接占空比控制策略在现场应用中达到控制目标的前提下,安全度更高。

The locomotive is in resistance braking condition,in order to ensure the intermediate DC voltage does not exceed the allowable working voltage must be controlled resistance braking chopper in the middle part of the.The first is the use of traditional hysteresis control strategy,but the switching frequency control method in IGBT are generally not fixed,if IGBT switching frequency is not fixed,is likely to lead to the detection of voltage harmonic spectrum is mixed in a wide range,which will increase the difficulty of detecting voltage filter design,This is the limitation of hysteresis comparison control method.This paper analyzed PI control,feedforward+PI control and direct duty ratio control of the advantages and disadvantages of the three kinds of control strategies,combined with simulation and field experience,proposed direct duty ratio control strategy to achieve the premise of control objectives in the field application,a higher degree of safety.