三相逆变器的最小共模电压PWM控制

摘要

提出了一种新的三相逆变器抑制共模干扰最优PWM控制策略。该控制方法在常规空间矢量控制策略的基础上,采用构造零矢量的方法来减小逆变器输出的共模电压幅值,并通过免疫算法来计算最优的作用时间,使得三相逆变器输出波形THD最小。本文介绍了算法各个操作步骤和零矢量构造方法的具体实施过程,搭建了基于DSP控制器的动态实验平台进行小容量模拟实验,实验和仿真结果表明该算法所产生的最优PWM控制序列与常规空间矢量控制策略相比不仅能有效地抑制逆变器输出的共模电压幅值,还能明显减小逆变器输出波形的总谐波畸变率。%A novel vector PWM method for three-phase voltage-control inverter is described.The novel PWM strategy is characterized by minimum common-mode interference of the three-phase inverter.In order to reduce common-mode interference,the method of non zero vector structure zero vector is used in this control strategy.The vector and the corresponding time of operation compose the PWM sequences generated by PWM strategy.An immune algorithm（IA） optimization technique is applied to determine the time of operation based on the output voltage vector of conventional space vector PWM（SVPWM）.Comparative analysis proving superiority of the novel vector PWM technique over the conventional SVPWM in common-mode interference and THD,and the results of the simulations and experiments of inverter confirm the feasibility and advantage of the proposed novel vector PWM strategy.