谐波检测算法中高性能数字低通滤波器的设计

针对有源电力滤波器(APF)的时域谐波检测算法,提出能够兼顾动态响应和滤波精度的高性能数字低通滤波器(HPLPF).在分析比较常用的无限长单位冲击响应滤波器(IIR)和滑动平均滤波器(MA)的特性后,采用优化级联的方式,构成高性能数字低通滤波器,利用巴特沃斯滤波器滤波精度高的特点以达到较高的滤波精度；利用滑动平均滤波器过渡带窄、动态响应快的特点以达到较快的动态响应.仿真分析表明,在存在间谐波的复杂谐波电流情况下,所设计的高性能数字低通滤波器能够更好地满足时域谐波检测算法的需求.

Design method of high performance digital low-pass filter in harmonic detection algorithm

In order to deal with the time domain harmonic detection algorithm of active power filter (APF), a high performance digital low pass filter (HPLPF) was presented, which can satisfy the requirements of dynamic response and filtering accuracy simultaneously. Infinite impulse response filter (IIR) and moving average filter (MA) were analyzed and compared. Then the HPLPF was introduced by cascaded MA filter and Butterworth filter optimally. The proposed high performance filter can fully use Butterworth filter to achieve more precise filtering results and improve dynamic response by using MA filter with its narrow transition zone and fast dynamic response. Simulation results show that the proposed HPLPF meets the demand of time domain harmonic detection algorithm better under the complex harmonic currents situation with inter harmonics currents.