A Digital Calibration Approach for Reducing Phase Shift of Electronic Power Meter Measurement

As the dedicated equipment in electricity measurement, high-accuracy metering is an essential feature of the electronic power meter. In actual measurement, various factors will affect the metering accuracy of energy metering system. Among them, the phase shift introduced by the current transformer is an important cause for the measurement error, especially in the case of a light load. The existence of this phenomenon will directly affect the fairness and justice of all the commercial transactions in the energy market. With regard to this matter, an effective digital calibration algorithm based on piecewise Lagrange interpolation for reducing phase shift of static meters is presented in this paper. Moreover, an analytical expression for the absolute error of the proposed algorithm is derived. The proposed method is advantageous, since it is simple, efficient, and is of high accuracy. The experimental tests have been performed to verify the effectiveness and feasibility of our calibration method.