The Research On Single-phase Parallel Hybrid Active Power Filter

Considering of the shortcomings of the passive filter and individual use of active power filter, this paper analyses the present study stage of hybrid active power filter, and summarizes the new research results on series hybrid active power filter and shunt hybrid active filter in recent years. The topology and filtering principle of the filters are introduced detailed in this paper. Advantages and disadvantages of these hybrid power filters are explained.A novel shunt hybrid active power filter based on the principle of magnetic flux compensation and the shunt technology of harmonic current is proposed and analyzed in this paper. Compared to needed APF capacity of other shunt hybrid active power filters, this novel filter's APF capacity is more reduced. In passive filter aspect,this article has used the double harmonious filter, its merit is that it is opposite in uses two list harmonious filter construction cost to be low. This paper accomplished theoretical analysis to the novel shunt hybrid active power filter, and introduces its principle. Calculation formulas about harmonic current that generated by APF and harmonic voltage of APF are deduced. Used the mathematics tool carried on the simulation analysis for various branch current and withstanding voltage of APF; In the area of reducing APF capacitance, the effect on the novel filter is obvious by comparing with APF capacitance of the conventional shunt hybrid active power filters (APF is in series with LC filter by transformer).To arrive at good filter effect, APF is controlled by the way of voltage comparison of passive filter and shunt reactor in the control strategy. In order to verify effectiveness of the novel shunt hybrid active power filter and to enhance its awareness and understanding on the control method, the paper builds up simulation model by power system module SimPowerSystem Blockset in Matlab/Simulink toolbox. The filtering effectiveness is analysis by the simulation model. The paper designs flow chart and hardware circuit based on digital control system. Simulation results show that the novel filter can effectively filter the vast majority of harmonics.