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提出了基于重采样的谐波检测方法 ,克服了数字化谐波检测瞬时无功功率法计算量大的缺点。当信号的最高频率为 ω时 ,第 1次采样频率为 ωf≥ 4ω。需要补偿 N′次以下的谐波电流时 ,重采样频率应不小于 (N′+1 +n) ω0 (ω0 为基波频率 )。当一个周期内的采样点数为 N1时 ,重采样频率为ωmin=(N1/4)ω0 。在重采样的基础上 ,继承了瞬时无功功率理论谐波检测方法的思想——将基波电流转变成直流分量 ,据此设计了一个数字谐波检测系统。仿真实验表明 ,该系统既具有数字系统的准确性和稳定性 ,又克服了数字滤波器计算量大和实时性差的问题 ,其动态跟随性有所改善
A harmonic detection method based on resampling is proposed, which overcomes the shortcomings of the large amount of calculation of instantaneous reactive power method for digital harmonic detection. When the highest frequency of the signal is ω, the first sampling frequency ωf ≥ 4ω. When it is necessary to compensate for harmonic currents below N ’times, the re-sampling frequency should be not less than (N’ + 1 + n) ω0 (ω0 is the fundamental frequency). When the number of sampling points in one cycle is N1, the re-sampling frequency is ωmin = (N1 / 4) ω0. On the basis of resampling, inherited the idea of instantaneous reactive power theory harmonic detection method - the fundamental current into direct current component, accordingly designed a digital harmonic detection system. Simulation results show that this system not only has the accuracy and stability of the digital system, but also overcomes the problem of large amount of calculation and poor real-time performance of the digital filter, and its dynamic followability is improved