The Research Of Distributed Power Quality On-line Monitoring System

With the development of the electric power industry, the power electronics broad application and the use of nonlinear devices, these factors make the power quality problems as the focus of both power suppliers and users. Power quality monitoring technology is the quantitative measure and appraisal method of power quality, how to real-time and accurate monitoring of electrical parameters is the core content of research. Grid structure changing, the traditional monitoring system has not meet demand and the distributed power quality on-line monitoring system are in urgent need of research and development.First of all, this paper introduces the measurement principle of the power quality indexes, discusses harmonic currents detecting methods, and chooses the FFT algorithm from the embedded development and large-scale use; next, it analyzes the using FFT algorithm of frequency spectrum leakage and fence effect, proposes interpolated FFT algorithm based on the ten terms cosine window, and deduces the algorithm and Matlab Simulink to verify the accuracy of the algorithm.According to the needs of distributed power quality on-line monitoring system, this paper gives the design proposal of the power quality monitoring device based on digital signal processor TMS320F28335, designs the circuit in detail including hardware and software, and accomplishes research and development of products. Compared with yokogawa power tester WT3000 measurement, it can be expected.