Research on Parallel and Average Current Control Strategy of Active Power Filter

The widespread use of lots of nonlinear loads have brought us great harmonics and reactive current pollution on grid system and reduced the quality of power supply. Installing active power filter in power side is commonly used to remove harmonics and reactive current of supply, making it provide fundamental component. As the nonlinear load increases, single active power filter cannot meet the large capacity of current compensation, therefore it needs some different or the same small-capacity high-frequency active power filter operating in parallel in order to reach a higher compensation effect. Firstly, it compares and analyzes several common parallel control strategies, and then proposes a new parallel scheme based on average and limiting current. The proposed scheme cannot only realize capacity expansion effectively, but also achieve hot-swap comfortably. Finally, it indicates accurate and reliable by simulation and verification of load's two situations in MATLAB.