电网不平衡时电压型PWM整流器混合无源控制

Hybrid Passivity Based Control of Voltage Source PWM Rectifiers under Unbalanced Voltage Conditions

针对国内外电网不平衡时电压型PWM整流器控制策略存在控制结构复杂和控制性能不佳的问题,提出了由直流电压环(PI)与无源电流控制器组成的电压型PWM整流器混合无源控制器。基于整流器的EL(Euler-Lagrange,EL)模型,利用阻尼注入方法设计了无源电流控制器。根据无源电流控制器确定出具有补偿电网不平衡功能的开关函数。该混合无源控制器只需电压、电流的实时值,通过混合无源控制器就可消除或抑制整流器输入电流中的所有谐波且使整流器具有恒定的直流电压;可使整流器具有良好的性能和简单的控制结构。仿真和实验结果表明,电网不平衡时电压型PWM整流器混合无源控制是可行的。

Aiming at that current control strategies of voltage source PWM rectifier under unbalanced voltage conditions at home and abroad exist complicated control structure and unsatisfactory control performances, hybrid passivity based control strategy by DC voltage loop(PI) and passivity based current controller is proposed in the paper. Based on EL model of the PWM rectifier, passivity based current controller is designed by damping injection method. According to passivity based current controller, switch function that can compensate unbalanced voltage conditions is obtained. All harmonics in input current of rectifier can be eliminated or restrained and DC output voltage of rectifier is kept constant by hybrid passivity based controller based on the real time value of voltage and current.Hybrid passivity based controller can make rectifier having good performances, and has simple control structure. Hybrid passivity based control of voltage source PWM rectifiers under unbalanced voltage conditions is proved feasible by simulation and experimental results.