It reduces the high hypo syntony wave output part included in the converted input current. 减少了变频器输入电流中包含的高次谐波成份的输出。
Unfortunately, they also suffer from some disadvantages, such as poor rejection to outside passband, and they are easily to be disturbed by high order harmonic frequencies. 但是也都存在一些共同缺陷,诸如带外抑制能力较差,容易受到高次谐波分量的干扰等等。