Research Of Parallel Active Power Filter Based On DSP

Firstly, this paper introduces the generation and hazards of harmonic, describes thecurrent situation of the harmonic governance at home and abroad, analyzes the topologyof the active power filter, and makes a comparison among the working principle andcharacteristics of series, parallel and the hybrid of series and parallel active power filter.It focuses on the working principle of the parallel active power filter, the detectionmethod of harmonic current, the control method of compensation current, the form ofthe main circuit and the control of DC(direct-current) voltage, then analyzes andcompares the two kinds of harmonic current detection method ip iq and ip iq indetail based on the instantaneous reactive power theory, and ultimately determines thei_p i_q algorithm as the harmonic detection method to detect the harmonic current. Thismethod has a simple implementation of the hardware circuit, a good real-timeperformance and the feature of fast current response, it can achieve the purpose of rapid,accurate harmonic detection. It selects the appropriate low-pass filter based on thedetailed analysis of the aspect of the filter which impacts on detection aspect largely,and builds the simulation model of the harmonic detection by the Matlab/Simulinksimulation tool to verify the real-time performance and effectiveness of the detectionmethod. It Also analyzes the advantages and disadvantages of the traditional controlmethod and proposes one kind of hysteresis loop control method based on RBF neuralnetwork to control the output of PWM, so as to make the actual compensation currentfollow the command signal changes of the compensation current to optimize the currenttracking performance of active power filter. The paper does a simulation study for thecompensation three-phase symmetrical load of the parallel active power filter, the resultshow good current tracking performance of the hysteresis control method based on RBFneural network. Finally, the detailed design parameters of the main circuit and the signalacquisition circuit of the active power filter are presented.