三相四线制系统任意次谐波电流的检测新方法

利用有源电力滤波器补偿电力系统的无功和谐波电流时,为实时准确地检测出谐波电流,根据通用瞬时无功功率理论,提出了一种适用于三相四线制系统的任意次谐波电流的检测方法。该方法以传统的ip-iq法为基础,适当修改变换矩阵就可检测不对称系统任意次谐波的正序、负序分量,再等价三角变换所得的每相电流零序分量以检测出任意次谐波的零序分量,相加所得的正、负和零序分量即得到任意次谐波电流。该方法克服了传统的ip-iq法不能用于三相四线制系统任意次谐波检测的缺陷,具有原理简单,检测精度高和稳定性好等特点。理论分析和仿真结果都证实了该方法的准确性。

New Algorithm for Random Harmonic Current Detection in Three Phase Four Wire System

Active Power Filter is an important device to eliminate the pollution of harmonic,the key problem in APF is to detect the harmonic current accurately in real-time mode.Separate usage of APF needs a lot of investment early and its running efficiency is low,so APF should be used with PF,but this kind of APF needs to detect the random harmonic current.In this paper a new detection algorithm for random harmonic current in three-phase four-wire system is presented.This algorithm which is based upon the traditional ip-iq method can detect positive and negative sequence component of random harmonic current respectively by properly modifying the switch matrix,also can detect the zero sequence current component by certain equivalent triangle conversion of the phase current's zero sequence component.Finally the detected positive,negative and zero phase sequence can be summed up to obtain the random harmonic current.This algorithm conquers the localization that the method of ip-iq can only be used in the harmonic detection in the system of three-face three-wire.This algorithm can be used not only in the random harmonic detection in asymmetry three-face three-wire system but also in the three-face four-wire system,so it has biggish practical value.The algorithm has a high precision and high stability.Analysis and simulation prove the correctness of the algorithm.