山东电力高等专科学校学报

基于瞬时无功功率理论的谐波检测方法中低通滤波器的设计在滤波效果方面很难兼顾动态快速性和精确性。本文针对谐波电流结构的特点,以滑动平均值算法替代传统的低通滤波器数字化算法,免去了复杂的数字滤波器设计。由平均值算法得到与基波正序分量对应的直流分量,具有非常理想的滤波精度和较快的动态响应;滑动平均值滤波器易于工程实践中DSP芯片编程实现,且程序设计避免了传统数字低通滤波器浮点数的运算,节省机时,提高了谐波补偿的实时性。仿真结果表明采用平均值算法的有源滤波器能准确地检测谐波并能及时跟踪负载变化,达到完美的滤波效果。

The design of low pass filter in the harmonics detection based on the instant reactive power principle is hard to accomplish both the dynamic rapidity and the accuracy. This paper introduces the moving average algorithm to substitude the traditional low pass filter and avoid the complicated design of the digital filter. The direct component which is corresponding to the fundamental positive component can be figured out,this algorithm can accomplish the ideal filter precision and fast dynamic response;meanwhile the moving average filter can be easily accessed to the implemention of the DSP programming,which avoids the traditional caculation of float variables,saves the computer clocks and improves the real time demand in the harmonic compensation.The simulation results have proved that the active power filter which adopts the moving average filter is able to precisely detect the harmonics and timely trace the variation of the load,which contribute to the perpefect effect of harmonic compensation.