Research On The Shunt Active Power Filter Based On DSP

With the development of power electronics, large-scale use of inverters and other nonlinear loads, the problems of harmonics pollutions are becoming increasingly serious in power grid. Using active filter(Active Power filter-APF)technology to suppress harmonics has become a trend. APF can be used to suppress the harmonic of grid and compensate reactive power of grid. APF device has an excellent performance of dynamic compensation.Most of traditional harmonic current detection methods can only detect the total harmonic current, this paperdeveloped a new harmonic current detection methods that can detects random harmonic current based on the instantaneous reactive power theory. This method can be used both for three-phase three-wire system, and three-phase four-wire system.This paper analyzed the principles of space vector pulse width modulation (SVPWM) in detail and gives a digital realizing method. This paper has established an active power filter system combining the above harmonic current detection method and SVPWM control strategy. After that, the paper carried out digital simulation of the whole system. Simulation result shows that the system can detect the harmonic current and compensate it accurately and rapidly.Based on the current detection and compensation strategy, design of the whole software and hardware of APF system is finished. The test circuit of the main part of the hardware is built and the experiment is completed.Based on control system software process, harmonic current detection,SVPWM and other major interruption procedures are developed and realized in the digital signal processor(DSP TMS320F2812)with the experimental waveforms and analysis.