采煤机牵引逆变器输出滤波电路的研究

Study of Coal Shearer Traction Inverter Output Filter Circuit

PWM逆变器输出的电压波形一般含有较多的高次谐波,这对电机的运行产生了很大的干扰,严重时,会使电机运行故障。针对PWM逆变器谐波含量多、谐波次数较高的特点,采用2阶LC低通滤波,对输出的电压进行滤波,降低了输出波形的总的谐波含量值,对纹波有较好的抑制效果。分析了LC滤波器的谐振抑制问题,并给出了LC滤波电路的设计,在6 k W的采煤机牵引变频器样机上进行了实验研究,对输出波形进行了检测和分析。

The output voltage waveform form PWM inverter typically contains many high harmonics which have brought a lot of disturbance to the motor. In some serious cases, it can cause motor running fault. According to the high harmonic frequency of the PWM inverter output voltage waveform, we use the LC low-pass filter circuit to filter the output voltage waveform to reduce the total harmonic distortion and get a better inhibitory effect of the ripple. We analyze the harmonic suppression of LC filter, and design the LC filter circuit. At last, we have an experimental study on 6 kW coal traction inverter, then detection and analysis the output waveform.