Nonlinear unified control for single-phase active power filter
单相有源电力滤波器非线性统一控制策略

Existing active power filter controllers are composed of the current inner loop and the voltage outer loop. We present a unified control method based on exact feedback linearization for the single-phase active power filter. By solving a partial differential equation, we obtain the output function containing the information of the compensation current and DC side voltage variables. The nonlinear state feedback control law is derived, thus transforming the nonlinear system into a diffeomorphism second-order linear system. By properly selecting feedback coefficients, we design the controller which forces the output function to asymptotically track the reference output, thus realizing the unified control of the compensation current and the DC side voltage. The efficacy of the proposed control method is verified by simulation and experiment.