基于Hermite插值同步化算法的电网谐波与无功测量方法

Harmonics and reactive power measurement based on Hermite interpolation synchronization algorithm

针对快速傅里叶变换(FFT)分析电力系统谐波及Hilbert变换测量无功功率时的采样非同步问题,推导出了基于两点Hermite插值的同步化公式。该方法对由固定采样频率采得的序列进行重新定位,利用Hermite同步化公式获得当前实际信号的同步采样序列,从算法上实现对信号的同步跟踪,然后用普通FFT变换分析各次谐波参数以及用Hilbert变换测量无功功率。仿真结果表明,用该方法进行电网谐波分析和无功测量,同步化公式简单,运算量小,测量精度高,对于工频波动较大的情况仍具有很好的分析测量结果。

To the problem of asynchronous sampling when analyzing power harmonics by FFT（Fast Fourier Transform） and measuring reactive power by Hilbert transform,the synchronization formula based on two points Hermite interpolation is derived.This method re-locates the data sequences sampled in fixed frequency and obtains the synchronous sampled data sequences by using Hermite synchronization formula.So it can track the signal synchroly.Then it uses FFT and Hilbert transform to analyze harmonics and reactive power respectively.Simulation results show that this method has simple synchronization formula with less calculations and high precision.It also has good results when the power frequency fluctuates greatly.