Research Of Active Power Filters Based On DSP

The harmonic pollution and its harm are introduced, and a general description about the development of harmonic elimination in power system and application foreground of Active Power Filter is given in this paper at first. The development of Active Power Filter's digital control technique is recalled. The advantage of digital control system based on DSP is also introduced. The principal and structure of Active Power Filter are expatiated. Basing on deeply analyzing theory of instantaneous reactive power, detecting method for high frequency harmonic current is presented and the diagram of actualization for digital control system is put forward.In this paper, a full digital Active Power Filter based on DSP is designed. Computing of instruction current and controlling of system are realized in one DSP. Hardware system using TMS320C32 type is completed, and the design of hardware interface and flowchart of software are given in this paper.In this paper, simulation models of Active Power Filter system in SIMULINK environment of MATLAB software are built for deeper theory analysis. A designed circuit system is simulated using the models. The simulation results prove that Active Power Filter can not only eliminate harmonic current effectively, but also have well dynamic compensation characteristics.Designing of digital low pass filter and the effect of its cut off frequency on precision of instruction current are discussed in this paper. From simulation we can see that the lower of the digital low pass filter's cut off frequency, the smaller of the instruction current's aberration.Experience from foreign country show that Active Power Filter has good application foreground. So its research and application is very important in the future.