PWM逆变器-感应电机系统中的过电压抑止滤波器研究

在PWM逆变器供电的感应电机调速系统中，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。本文从时域和频域分析了过电压的内在特点，给出了过电压振荡频率与系统参数的函数关系式，根据过电压的形成机理及其特点，以R－C滤波器为例，给出了详细的滤波器参数选取方法。仿真和实验结果证明了按照本文所提供的方法设计的滤波器能够很好地抑止电机过电压。

Study on filter for reducing terminal over-voltage of motor fed by PWM inverter

An over-voltage, nearly 2 times of bus voltage of the PWM inverter, may be presented at the motor terminals if the length of cable between the motor and the inverter is longer than a critical length. The inherent characteristic of the over-voltage is revealed in this paper, and the ringing frequency of the over-voltage depends mainly on the parameters of cable. The parameters of the typical filters, R-C filter and L-R-C filter can be easily specified, and as an example, selection of R-C, of the R-C filter parameters is presented in detail. Simulations and experiments proved that satisfied results are achieved in restraining terminal voltage with the filters according to proposed methods.