Harmonic current detection based on asymmetric notch filter
基于不对称陷波器的谐波电流检测方法*

According to the base-adaptive detecting method of harmonic current,this paper proved that the weight vector of base-adaptive method was a variable value that contained direct part and 2 harmonic,so this system couldn’t detect harmonic current accurately.Based on analysis above,this paper proposed the asymmetric notch filter method.In this method,a 2-order low-pass filter was in base-adaptive system.This paper discussed the stability of improved system.Then theoretical analysis and simulation test showed the bandwidth had been reduced nearby reference frequency.Simulation shows that the dynamic performance is in a period and the harmonic distortion rate is no more than 1.7%.