PWM整流器瞬时功率控制策略研究

Study on Instantaneous Power Control Strategy for the PWM Rectifier

三相电压型PWM整流器一般采用电压电流双闭环控制策略,而电压方程的非线性特性使得系统分析变得困难。建立了PWM整流器控制系统的瞬时功率模型,证明了线性控制方案电压误差与输出功率之间为线性关系。比较研究了PWM整流器的线性PI控制和基于负载功率前馈控制两种线性瞬时功率控制策略,指出后者大大加快了系统响应速度。在此基础上,针对输出电压方程非线性的特点对后者进行了改进,在保持该策略优良性的同时,实现了输出电压的线性控制。仿真和实验结果表明了该控制策略的正确性。

The voltage and current double closed loop control is usually used for the three phase volatage PWM rectifier, and the nonlinear characteristic of the volatge eqatioa gives more trouble to analyze the system.The instantaneous power model is eatablished,which proves the linear relation between the voltage error and the output power with linear control strategy.A comparative study of two linear instantaneous power control strategies for PWM rectifier is presented,that is linear PI control and control based on load power feed-forward.It is pointed out that the system response can greatly be quicken by the load power feed-forward control.Then aiming at the nonlinear equation of the output voltage,the control strategy based on load power feed-forward control is modified,which inherits the advantages of the control strategy and realizes the linearization of output voltage control.The Matlab simulation and experimental results indicate the validity of the control strategy.