Research On The Shunt Active Power Filter

With the development of power electronics technology, a sharply increasing number of power electronics devices have been widely used nowadays. Although these power electronics devices make our life convenient, they inject much harmonic current to the power grid for their nonlinear characteristics. Another aspect, the development of information technology have made more and more equipments, which based on computer and microprocessor control technology, put in use. These equipments have a comparatively high requirement to power quality, which stop to work or evenly brake the wholly system once the power quality problem appears, the economic losses bringing about from this is difficult to estimate. Therefore, harmonic current compensation is regarded highly.Active Power Filter (APF) is one of the effective means for harmonic current compensation and power quality improving. The thesis takes the small capacities APF equipment designing as main job, whose purpose is that to build a platform and hardware support for APF's research.Firstly, the thesis covers the characteristics and classifies of APF,analyzes shunt-APF's structure and operating principle, introduces the topologies of it's main circuit and builds mathematic model.Secondly, the method of harmonic current detection and compensating current control were discussed; The overall system has been modeled using MATLAB/Simulink, and simulation results have shown that the structure is reasonable.Finally, the parameters in main circuit of 3KW shunt-APF is designed, control system's hardware is also realized based on M16C MCU and TMS320VC5402 DSP. In the control system the method of compensating current control is instantaneously comparing, and the method of harmonic current detecting is based on instantaneous reactive power theory. After debugging first step's result was gotten, and it shows the designed structure is reasonable, the theories which were adopted are correct.