基于复指数型有限长脉冲响应滤波器的谐波检测

Harmonic Detection Method Based on Exponent FIR Filter

提出了一种简单实用的基于复指数型单位脉冲响应的滤波器,并将它用于电网谐波电流的检测,该滤波器在基频处的幅值无衰减,相位无延时,能将2次以上的谐波全部滤掉,在一个周期内准确地跟踪上基波的变化。理论推导和仿真实验表明,该数字谐波检测系统既保留了数字滤波器的准确性,又克服了长期以来数字滤波器动态跟随性差的问题,算法易于实现。

A simple and practical instantaneous harmonics current detecting method based on exponential FIR filters is proposed. The amplitude of this filter is 1 in first-harmonic frequency, the amplitude is 0 in other harmonic, and the phase of the filter is 0 in first-harmonic frequency. The theoretical analysis and simulation have shown that this filter not only take advantages of digital filters in the accuracy, but also overcomes the bad dynamics performance.