摘要
在PWM逆变器供电的交流电机调速系统中,当逆变器与电机之间的电缆超过一定长度后,在电机端可能出现2倍于逆变器直流母线电压的过电压,过电压可能会导致电机绝缘失效。这一现象同样存在于多逆变器并联供电的交流电机调速系统中。提出了一种多逆变器并联供电的交流电机过电压抑制方法,在不使用任何滤波器的情况下,通过对各逆变器PWM脉冲宽度进行调整,达到抑制电机端过电压的目的。通过对2个和3个逆变器并联供电情况的分析给出了奇数和偶数逆变器供电的交流电机过电压抑制方法。实验结果证明了按照该方法能够很好地抑制电机过电压。
An over-voltage, nearly 2 times of the voltage of the PWM inverter, may occur at the motor terminals if the motor is fed through a long cable in the AC motor speed regulation system. The over-voltage may result in a premature motor insulation failure. The phenomenon also exists when the motor is fed by parallel inverters. A method for over- voltage mitigation of active motor fed by parallel inverters was presented.Without any passive filters, the width of the pulse of every inverter is adjusted to reduce the over-voltage of the motor. Methods for odd and even number of inverters are presented through the design of two and three parallel inverters. Experiments prove that satisfied results are achieved in reducing terminal voltage according to proposed methods.
出处
《电气传动》
北大核心
2013年第5期8-10,32,共4页
Electric Drive
关键词
交流电机保护
并联逆变器
过电压保护
AC motor protection
parallel inverters
over-voltage mitigation
