无功、负序及谐波电流检测中的数字滤波器研究

Research on Digital Filter for Reactive,Negative Sequence and Harmonic Current Detection

数字滤波器是基于瞬时无功理论的无功、负序及谐波电流检测中一个重要部分,其精度和速度直接影响检测的结果。文中在各种电压和电流情况下对电流检测中所需要的数字滤波器进行分析,得出数字滤波器分类设计的想法,并优化设计出三种适用于不同电压和电流情况的数字滤波器。仿真和实验结果证明所设计的数字滤波器与目前电流检测中使用的数字滤波器相比,在保证精度的同时能有效提高速度,且本身算法的复杂性并未显著增加。

The digital filter is an important part in reactive,negative sequence and harmonic current detection which is based on the instantaneous reactive power theory.The accuracy and speed of digital filter has effect on the result of current detection.Analyzed the digital filter which is used in the current detection under all kinds of voltage and current conditions,the idea of digital filter classification design is proposed.The three optimized digital filters are designed which are suited for different voltage and current conditions.The simulation and experimental results validate that compared with the currently used digital filter,the speed is improved obviously and accuracy is kept for the designed digital filters.The complexity of filters also is not increased significantly.