The Measurement Of Harmonics In Power System Based On FPGA

Since the power system was born, harmonics in power system had been in existence. With the extensive use of electronic installations, harmonic problems become increasingly serious, power system harmonic has already become the public hazard of power system. Harmonic measurement is one important branch of harmonic research and the foundation to solve other harmonic problems ,so there is important theoretical and practical significance in research of harmonic measurement .This thesis mainly probes into the digital harmonic measuring system with high accuracy , high real-time character in measuring theory and realized approach .The thesis explaines the relevant concepts of power system harmonic and the principle of harmonic producing, the thesis analyses the character of harmonic. In measurement theory, the thesis adopts FFT theory to calculate harmonic content, studys the process of Radix-2 FFT for harmonic measurement, expatiates the phenomenon and analyses the theory of frequency spectrum leakage.In order to solve the problem of frequency spectrum leakage , the thesis proposes the technology of phase locking synchronous sampling control circuit, the technology can track the change of power system frequency to reduce leakage. In the harmonic measurement, FFT has a very large operation amount with high speed and precision . The thesis probes into FPGA to realize the FFT digital signal processing.