Bandpass Filtering Scheme for Improving Phasor Measurement Accuracy

The increasing penetration of the renewable energy sources have dramatically changed the dynamic characteristics of the distribution network. The distribution-level phasor measurement unit (D-PMU) has drawn worldwide attention. In order to reduce the errors caused by interharmonics in synchronous phasor measurement, this paper proposes a filtering scheme suitable for hardware devices. Firstly, the filter bank parameters are determined based on the fundamental and harmonic characteristics. Then, a scheme of extracting the fundamental wave using zero phase filtering is proposed. Finally, a scheme for extracting harmonics by combining primary filtering and least squares fitting is proposed. The simulation results and hardware test results show that the accuracy of phasor calculation is greatly improved and the robustness of the phasor measurement algorithm is significantly enhanced.