The analysis and compensation of dead-time effects on Active Power Filter in α-β coordinate

A novel topological structure of Active Power Filter (APF) in alpha-beta coordinate is presented based on transformation of three phase static A-B-C coordinate to two phase static alpha-beta coordinate. The topological structure adopts two groups of single-phase inverter as main devices of APF, and can realize transformation of current source from two phases to three phases by using a special transformer connection. Dealing with the issues of dead-time effects of inverter in APF as subject investigated and comparing the APF of new topological structure with traditional three-phase three-line APF in A-B-C coordinate. Firstly, the impacts caused by dead-time on system compensation were calculated. Then, the error was compensated to optimum value by controlling two kinds of APF in condition of dead-time. Investigation shows that the novel topological structure of APF is less affected by un-modeled parts and helps to alleviating maladjustment from coordinate transformation of nonlinear power electronic system in controlling arithmetic.