两种谐波电流检测方法的比较研究

谐波电流检测方法有许多种，所以有必要对各种检测方法做一比较，以便充分利用每一检测法的特点，该文首先简要介绍了谐波电流检测的两种方法，即基于鉴相原理的瞬时谐波电流检测法和基于自适应干扰对消原理的自适应谐波电流检测法，而且通过数字仿真和理论分析对这两种方法在频域和时域的各自特性作了分析比较。研究表明适当地选择比例系数K，可以使自适应检测法有较高的检测精度。但是，其检测精度的提高是以牺牲其动态响应特性为代价的，适当地选择滤波器的类型，阶数和参数，可以使瞬时检测法对谐波分量的检测有比较高的精度，同时又有较快的动态响应特性。

A STUDY ON THE COMPARISON OF TWO HARMONIC CURRENT DETECTING METHODS

There are so many harmonic current detecting methods that it is necessary to compare various methods in order to take full advantage of the characteristics of each method. This paper introduces two harmonic current detecting methods, an instantaneous harmonic current detecting method based on the phase distinguishing technology and an adaptive detecting method based on the adaptive interference canceling theory. Through numerical simulation and theoretical analyses, their characteristics are analyzed and compared in both time and frequency domains.A satisfactory detecting precision of the adaptive detecting method can be achieved by setting the integral gain K to the appropriate value. However, the higher detecting precision often conflicts with the faster dynamic response.A better tradeoff between the harmonic current detecting precision and the dynamic response of the instantaneous detecting method can be achieved by carefully choosing the type, order and the parameter of the low pass filter.