A Study on Harmonic Detection of Power Metering Errors under Distributed Energy Access in Low-voltage Stations

When distributed energy sources are connected to a low-voltage station area, to grasp the harmonic situation of electric energy measurement errors in the station area and ensure the accuracy of measurement, a harmonic detection method of electric energy metering errors under the access of distributed energy sources in low-voltage station areas is proposed. This method uses wavelet transform technology to process the harmonic signals in the operating current signals of low-voltage stations after the distributed energy is connected, and extracts the fundamental wave and harmonic components in the signals. A linear neural network is used to build a harmonic detection model, and the extracted signals are input to the constructed model to calculate the amplitude and phase of the harmonics to detect the harmonics of electric energy measurement errors. The test results show that when the optimal transformation order is 1.0, the wavelet transform can more accurately extract each harmonic in the current signal; the maximum error in the harmonic detection amplitude of the electric energy measurement error is 0.26A, and the maximum error in the phase is 0.33°; It can accurately detect the integral harmonics and non-intact harmonics of electric energy measurement errors.