| With the rapid development of aluminum industry, aluminum industry using high-capacity rectification system will bring a large number of high-order harmonic to power system,causing waveform distortion of the power system, power quality decreased, severe system damage, threaten the safe operation of the equipment,furthermore, It will accelerate the aging of power cable in aluminum factory and reduce life of power cable,.It appears more and more failure events, therefore, the problems caused by harmonics need to be resolved.Active filters as an effective harmonic suppression and reactive power compensation of power electronic equipment, attracted widespread attention. First introduced the theory,concept, hazards of harmonic and reactive power, and analyzed the structure and principle of active filter and passive filter, outlined their advantages and disadvantages.In harmonic current detection technology, analysis and derive the instantaneous reactive power theory,compare the different points of p ?q detection method and p qi ?i detection method.By analyzing the results we know p qi ?i detection method has good accuracy and reliability. It analysis the triangular carrier control method and hysteresis control method detailedly in the current tracking control.It uses MATLAB / Simulink build circuit simulation model of a aluminum plant with harmonic source,makes the simulation analysis for 6-pulse and 12-pulse rectifier circuit, and uses FFT Analysis tool in Powergui doing some Fourier system simulation analysis for a number of important variables reaching its frequency spectrum.Setting up the Shunt Active Power Filter simulation model based on active power filter instantaneous reactive power theory and analyzing and calculating parameters.Finally we design an active filter meeting the requirements of system.Analysis shows that this designed active filter has ideal filtering effect, which achieve the effect of suppressing harmonics and improve system power factor. |
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