Research On A Novel Shunt Active Power Filter Based On Harmonic Magnetic Flux Compensation

The wide use of power electronic equipments makes harmonic problem deteriorated increasingly in the power system. Harmonic badly influences power quality of the electric network. Compensation device can help to reduce harmonic and improve power quality. Active power filter (APF) which is a new electrical electronic device can suppress harmonic and compensate reactive power. Because APF conquers many disadvantages of the LC filter, it received widely attention.Firstly the thesis introduces the background and the development of APF, then analyses the operational principle and structure of the different APF especially the shunt APF according to the classifications.According to the linear transformer's voltage equations and the study of the port's impedance characteristic, the thesis analyses the magnetic flux compensation theory, and proposes the operational principle and the structure of a new shunt APF based on the magnetic this theory.Two current detection methods of the APF are discussed in the thesis. We make the simulation for the current detection method based on the phase demodulation theory. Active power filter's control strategy and inverter's output control are analyzed in detail. The thesis adopts triangle wave compare control and monopole frequency doubling PWM mode.MATLAB6.5 is employed to make the simulation for the new shunt APF. Finally a suit of experiment set for low voltage is designed. We go on experiment of various work conditions. Simulation and experimental result have proved that this scheme is correct and feasible.