【摘要】 了解高压变频系统共模电压及其特点 ,对整个变频系统的设计具有重要意义。文中较详细地分析了级联型多电平高压变频系统共模电压的产生机理 ,对两种电压胞脉宽调制 (PWM)方法引起的共模电压进行了比较 ,提出了采用电压胞异相调制和 3次谐波注入法减小变频系统共模电压的策略。仿真计算表明 ,该方法既能减小变频系统输出共模电压 ,又不致降低直流电压利用率更多还原

【Abstract】 It is important to analyze the characteristics of common-mode voltage of medium-voltage variable frequency drivers(MV-VFD) for proper design of the total driver system. In this article, details of common-mode voltage of cascaded MV-VFD are discussed. Moreover, based on the comparison of common-mode voltages caused by two modulation methods of power-cell, a PWM modulation strategy using out phase modulation wave and third harmonic injection method is suggested to reduce the common-mode voltage of VFD and maintain high utilizing ratio of DC-link voltage at the same time. Also, the proposed strategy is verified by simulation results.更多还原