基于不对称陷波器的谐波电流检测方法

摘要

为了克服常规自适应算法由于权值是一个合有二次谐波的波动量导致基本自适应算法不能准确提取出谐波电流的缺点,提出了一种基于不对称陷波器谐波电流检测方法.该不对称陷波器的实质是通过加入一个低通滤波器改变了陷波器参考频率附近的带宽,从而在保证动态相应的前提下兼顾系统的检测精度；验证了该系统是一个稳定系统,证明了改进后的不对称性,给出了参数选择的依据.通过仿真实验表明,该系统可以在一个周期内就能稳定跟随,系统的畸变率可以控制在1.7％以下.%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-or-der 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%.