一种基于移相对消的单相谐波电流提取方法

摘要

In order to solve the problem that the 100 Hz component is difficult to be filtered out with traditional instantaneous harmonics detecting method in single phase system, an improved harmonic current detecting method based on phase-shifted cancellat.This method can eliminate the second wave of fundamental wave extraction theoretically, so it makes the design of the low-pass filter easier. The traditional method of harmonic current detecting is firstly introduced and then an improved method based on phase-shift cancellation is put forward.Through the digital simulation and experiment, the characteristics are analyzed and compared.The results show that the low-pass filter can be designed in the higher cut-off frequency, meanwhile extraction and the dynamic response turned to be perfect.%为解决传统单相系统瞬时谐波电流检测中难以滤除100Hz谐波的问题,提出一种基于移相对消的改进 型谐波电流检测方法,从原理上消除了基波提取中的2次谐波,在很大程度上降低了低通滤波器(LPF)的设计难度.这里首先介绍了基于锁相原理的传统谐波电流检测方法,在此基础上提出了基于移相对消的改进方法,并通过数字仿真和实验对二者特性进行了比较研究.研究结果表明,改进型单相谐波提取方法可将LPF设计在较高截止频率下,并能获得较好的谐波提取效果和动态响应特性.