A Bidirectional Electric Energy Metering Algorithm Based on the Fundamental Component Extraction and Alternating Current Sampling

Abstract

T380 rapid development and application of distributed generations have introduced the need for bidirectional electrical energy metering. Moreover, the nonlinear or time varying parametric loads used in power grid have brought about the necessity of metering the fundamental energy, high harmonic energy, active energy and reactive energy respectively. Therefore, based on the analysis of the characteristics of main existing electric power metering algorithms and combined with the four-quadrant power measurement principle, three bidirectional power metering algorithms are presented and discussed in this paper. The first algorithm is based on Fast Fourier Transformation, the second algorithm is based on Fast Fourier Transformation fundamental component extraction, and the third algorithm is based on alternating current sampling. By integrating the merits of these three algorithms, a bidirectional power-metering algorithm based on fundamental component extraction and alternating current sampling is proposed. Finally, results of theoretical analysis and ARM platform tests demonstrate that the proposed new algorithm has smaller computational cost compared with the first FFT-based algorithm. In addition, the results of Matlab simulation indicate that this new algorithm can respectively meter the fundamental energy, high harmonic energy, active energy and reactive energy while accuracy is guaranteed. This new algorithm can also determine power state and current direction, and thus realizing the metering of bidirectional electrical energy.