Error Detection of Electricity Meters Based on Three-phase Dynamic Harmonic Analysis
Interference of harmonics in original signals causes large deviations of detection results of electricity meters from actual situations.Therefore the present study proposed an electricity meter error detection method based on three-phase dynamic harmonic analysis.In the harmonic analysis stage,considering harmonic-dynamicity-induced asynchronous sampling among signals of the three phases,cosine combination window-side lowest and fastest drop window was constructed and used to separate discrete meter signals so as to avoid leakage of signal energy to adjacent spectrums.And then the extraction of harmonics could be realized by signal processing using discrete Fourier transform.In the error detection stage,guided by probability density function of the discrete random signal,the optimal histogram curve fitting method was used to analyze it,and error calculation was performed from the distribution state of the standard signal.The application of the proposed method can achieve good control of deviation in electricity meter error detection within 3.0%.
three-phase dynamic harmonic analysiselectricity meter errorlowest and fastest drop windowdiscrete Fourier transformprobability density functionoptimal histogram curve fitting method