Novel Hybrid Single Phase Active Power Filter

Currently, the research on active power filter is more on three-phase three-wireand three-phase four-wire active power filter, while less on the single-phase activepower filter. But the application amount of single-phase power electronic equipmentis very large, which causes serious harmonic pollution to the power grid. In addition,the harmonic current detection and control, DC side voltage control of single-phaseactive power filter both have their own specific problems. The selected harmonic canbe filtered by the passive filter, and the power factor can be improved by the reactivepower compensator. When combing the advantages of the two former, it will not onlyreduce the capacity of single-phase active power filter, but also simplify itself toimprove the cost-effective ratio. Therefore, the research of novel hybrid single-phaseactive power filter is of great practical significance. This paper discusses a new kindscheme of harmonic current detection and control, and then conducts an experimentset-up of novel hybrid single-phase active power filter for experiment study.Firstly, the domestic and international research status as well as the developmenttrends of the hybrid active power filter was reviewed for this paper. On this basis, thewindowed Fast Fourier Transform of harmonic current detection scheme, thecombination between PI control and repetitive control of harmonic compensationscheme was put forward. After it, the overall scheme and functions of the system wasdetermined, also the research ideas were developed.Secondly, the overall structure of novel hybrid single-phase active power filterwas ascertained. According to the particularity of single-phase systems and theanalysis of common harmonic current detection methods, the harmonic currentdetection method of windowed Fast Fourier Transform, the integrated control methodof PI control and repetitive control were put forward. Through MATLAB simulation,windowed Fast Fourier Transform method and three-phase instantaneous reactivepower theory, which is widely used at present, were both applied in single-phaseactive power filter. The results showed that the detection method of this paper wasmore accurate in detection, more convenient in application. Afterwards, anobservation and control synthesis simulation was carried out for the design of novelhybrid single-phase active power filter. The results showed that the use of integrated control method improved the harmonic compensation effect.Then, the hardware design and software design of novel hybrid single-phaseactive power filter were finished. Besides, it was focused on single-phase activepower filter while taking passive filter and reactive power compensator as asupplement. In the hardware part, STM32F103ZET6chip was selected as the core,and a control circuit and a drive circuit were created based on it. In the software part,the procedures of new observation and control method were realized about windowedFast Fourier Transform as well as PI control method and repetitive control method.Also, the uC/OS-II real time operating system was transplanted to realize multi taskoperations.Finally, an experiment device of novel hybrid single-phase active power filterwas built up. Later, the experiments of harmonic current measurement and controlwere conducted, mainly about the windowed Fast Fourier Transform, PI control andrepetitive control method. And the feasibility of the control scheme used in this paperwas preliminarily verified.