中文说明：
在电网电压不平衡条件下，采用陷波器不能消除2的震荡，且也不能对谐波消除。研究发现电压的正序和负序的振荡分量相吻合。不平衡整流。
English Description：
< p > Under the condition of unbalanced grid voltage, the notch filter can not eliminate the oscillation of 2 and the harmonic. It is found that the oscillation components of positive sequence and negative sequence are consistent. Unbalanced rectification.