Lyapunov Function Based Control Strategy for Hybrid Active Power Filter

Abstract

To improve the harmonic current compensation performance of the active power filter (APF), reduce its cost, a kind of hybrid active power filter (HAPF) composes of a passive filter and an active power filter in series is studied, which permits a lower DC bus voltage and reduces the rating of active power filter greatly. On the basis of establishing mathematical model which includes the passive filter and an active power filter, a Lyapunov function was constructed, and then an appropriate control law was selected to make its leading function is negative definite, so that the steady tracking for harmonic current was realized. From the robustness and tracking performance perspective, the turning range and the optimization goal of the control gain was given by derivation. An auto-disturbance-rejection proportional integral (ADR-PI) control is adopted in outer DC bus voltage control loop which can enhance the ability to resist load disturbance efficiently. At last, the simulation analysis and experiment verify the feasibility and the superiority of the control strategy.