The Research Of Harmonic Detection And Analysis System In Guixi Smelting Factory

Based on the research of the harmonic problem of the power system, the main academic and techniques research of harmonic have been introduced. Combining with the project of Guixi Smelter and the college of Electric and Information Engineering of Hunan University, an instrument for multi-channel harmonic detection and analysis has been researched.The paper was divided into four chapters.In chapter one, the harmonic fundamental concepts and harmonic harm to rotating electrical machine, relay protection and communication systems were discussed; and then the present condition of harmonic problem and standard of harmonic in power system were described.In chapter two, the Flourier Series and Flourier Transform as well as fundamental theories of harmonic analysis were introduced; the characteristic of harmonic in the power system was summarized; and then the main purpose, content and methods of harmonic detection were described; at last a brief introduction of harmonic administration was given.Combining with the practical project, the development of an instrument for multi-channel harmonic detection and analysis were described in the third chapter, including the system structure, hardware and software of the device. Then the technology of multi-channel data gathering was discussed, and some key techniques have been presented including high precision,high speed sampling of the voltage and current, Fast Flourier Transform(FFT), data compression and storage techniques, planar graphic fitting,three dimensional graphic projection, multithreading and the computer graphics techniques .In chapter four, the project techniques of harmonic filter and reactive power compensation for Guixi Smelter were firstly discussed; based on the harmonic condition of Guixi Smelter, the key techniques of a new hybrid active power filter with high capacity for harmonic filter and reactive power compensation were proposed; then the designs of main configuration, output filter, harmonic detection and analysis subsystem, and the controller based on DSP have been discussed. Application results of the hybrid active power filter have confirmed the feasibility of the integrated compensation system.