一种用于有源滤波器的改进谐波检测法

An Improved Harmonic Detection Algorithm for Active Power Filter

对谐波进行准确、快速检测是有源滤波器发挥良好效果的基础,针对快速、准确检测的需求,提出一种abc坐标直接投影谐波检测法。对广义的IP-IQ检测法进行简单介绍;并在此基础上提出abc直接投影谐波检测法,该检测法直接对旋转坐标进行投影,相对于IP-IQ法省去了坐标变换的中间环节,具有易于编程、计算量相对较小的特点。同时指出该方法存在低通滤波器延时的缺陷;并针对此缺陷进行改进,应用滑动均值算法来替代原检测法中的低通滤波器,缩短了算法延时且省去了复杂的低通滤波器设计环节,将计算量分散开,且编程较为简易。通过搭建MATLAB/Simulink仿真平台对改进的谐波检测算法进行仿真,结果显示,该算法具有准确性高、延时量小的特点,可以满足有源滤波器的谐波检测需要。

Accurate and fast detection of harmonics is the foundation for the active power filter to play a good effect. Regarding the requirement of fast and accurate detection,a harmonic detection method based on direct projection of abc coordinates is proposed. A brief introduction to the generalized IP-IQ detection method is given.Based on this,this harmonic detection method based on direct projection of abc coordinates is put forward. This detection method directly projects to the rotational coordinates,and saves the intermediate part of the coordinate transformation compared with the IP-IQ method. It is characterized by easy programming with relatively small amount of calculation. Meanwhile,time-delay disadvantage of low-pass filter is pointed out in this detection method,and improvement measures are provided accordingly. The moving average algorithm is used to replace the low-pass filter in the original detection method. In this way,the algorithm delay is shortened and the complicated design of low-pass filter becomes unnecessary. As a result,the amount of calculation is dispersed and programming is simpler. The improved harmonic detection algorithm is simulated by building a MATLAB/Simulink simulation platform. The results show that the proposed algorithm has features of high accuracy and small time delay. Therefore,this algorithm can meet the harmonic detection needs of active power filters.