Reaserch And Design On Power Harmonic Analysising System Based On LabWindows/CVI

This paper introduces the design scheme of power harmonic analyzing system based on LabWindows/CVI. It achieves the analysis of harmonic combining LabWindows/CVI with hardware in Industrial Personal Computer. It has the advantage of high accuracy and anti-jamming performance which meets the test of power system.At first, it presents situation and analyzing measurement about power harmonic, discusses the significance of harmonic detection of the existing, then finds the corresponding measurement method after the corporision to design the whole system.Secondly, it discusses the problems in the harmonic measurement and signal processing when signal sampling, analysis and display then puts forward the corresponding solutions. improving the FFT.Thirdly. detailedly depict the hardware and software design of power quality analyzing system. Adopt virtual instrument system basing on PCL-818HG and PCLD-8115to accomplish hardware setting up. In software, it bases on LabWindows/CVI platform to accomplish driving and detecting of power harmonic indicators includes acquiring signal, analyzing signal, saving signal. Measure the frequency by Zero Cross Detection. Measure the amplitude and phase of fundamental and harmonious harmonic by Fourier Transform with window.Finally, analyze the error of the measuring data and propose improving measure. Depict the shortage in this design, and make a prospect for the trend of power harmonic analyzing.