The Research Of Active Power Filter In Grid-Connected PV System Based On One-Cycle Control

In the 21st century, human society is facing a shortage of fossil fuels serious environmental pollution and ecological situation. Photovoltaic power generation has become focused in energy research. According to the actual power supply situation, photovoltaic power generation will become a new trend of photovoltaic power generation. In grid-connected PV system, the design of grid AC side filter is very important. Filters are divided into PPF and APF. Traditional filters use LC filter. Compared to LC filter, active power filter has many advantages; perhaps in the near future APF will replace the LC filter. The basic idea of active filter is injecting the harmonic currents to the AC power in order to reduce the harmonics wave in power.This paper focuses on the research of Active Power Filter in grid-connected PV system based on one-cycle control. The main contents are as follows:First, this paper analyzes the background and structure of grid-connected PV system and APF, and focused on the APF principles, and the significance of the introduction of APF.Second, this paper introduces the control method of APF. By contrast the one-cycle control method was selected, and elaborated on the principle. Based on the analysis and calculations of mathematical models, this paper designed the single-phase and three-phase circuit to achieve APF based on one-cycle control , used MATLAB/Simulink simulation software for circuit simulation, and achieved a good filtering effect.Third, in grid-connected PV system, the network control strategies and filter directly affect the quality of current. The selection of the appropriate network control strategy is also very important; this paper analyzes the network control strategy and selects PI control. The APF based on one-cycle control is added into the grid-connected PV systems, and its simulation results show that the APF based on one-cycle control can effectively compensate for harmonics wave generated by photovoltaic power generation system connected to grid.