Research And Design On The Control Of Active Power Filter Based On DSP

With the increasing development of the national economy and the improved people's living standards, the power electronic products is used widely in nowadays, and then it required that the power quality is improved to satisify the users. The power quality requirements of users are mainly the voltage quality and the harmonic problem. All kinds of power electronic devices have used widely in industry so that it indroduces a large number of non-linear load into the power supply system. And then these non-linear loads lead to a lot of high harmonics and reactive power in the power grid, which brings severe disturbance to the power system, loads and the normal use of adjacent electrical equipment.As one of the important means to effective management of harmonic problem in power system and improving power quality, the active power filter has a great characteristic of filtering and compensation. With the development of digital signal processing, the active power filter which based on digital controlling has become a new hotspot in power electronics. In the high-tech future, the active power filter must be as the most important means to improving and controlling the power quality, of which shunt active power filter also will occupy the most mainstream status.In this paper, the reaserch object is three-phase shunt active power filter which is the most basic and practical and most benefical industrical. A series of more systematic and in-depth theoretical study and analysis are discussed, which lay out some basis for its practicality.Firstly, the thesis introduces the system stuctrue of shunt-APF, analyzes the hardware of APF, including the main circuit, AD conversion circuit, data acquisition circuit, etc. then designs the major DSP software flow chart, and estimats parts of the main circuit parameters. Secondly, the harmonic current detection approaches and the current tracking control strategies for APF is analyzed detailedly. And their advantages and disadvantages and application scope are introduced.Finally, in Matlab / Simulik, a three-phase shunt active power filter system simulation model is set up. The parameters of dc-link capacitor and inductors are determined by trial and error, and these datas show the impact of the paramenters on APF getting rid of high harmonics. In the simulation experiment, the correctness of real-time harmonic current detection method and accuracy of current tracking control strategy is verified. At the same time, the simulation results also show that the impact of system parameters seletion on APF's compensation.