Analysis and compensation of active power measurement error caused by non-integer period sampling

Abstract

A software compensation method is proposed in this paper to reduce the active power measurement error which is caused by non-integer period sampling in the electrical energy measurement process. In the process of electrical energy measurement, the sampling frequency is fixed, and it is an integer multiple of the standard frequency. When the grid frequency fluctuates, the real-time frequency deviates from the standard frequency, therefore, the sampling rate is not strictly the integer multiple of the grid frequency, which may leads to active power error. In this paper, we firstly calculate the analytic equation of active power error in non-integer period sampling, which includes the theory value and the error value, then the active power value of integral period sampling can be obtained by subtracting the error part. Finally, the MATLAB simulation shows the correction and effective of the compensation method, and it can significantly improve the accuracy of energy measurement.