Backstepping Control of High-Frequency Link Matrix Rectifier for Battery Chargers

High-frequency link matrix rectifier (HFLMR) is getting much interest in electric vehicle charger applications due to its high efficiency and compact volume. However, the inputs and outputs of HFLMR are highly coupled resulting in reduced system dynamic performance and robustness. This article proposes a dual closed-loop backstepping control (DCL-BSC) strategy to solve these problems, which consists of a dc output current outer-loop controller and a grid current inner-loop controller. First, the nonlinear mathematical model of HFLMR is established, and the six-segment space vector pulse width modulation scheme is used as the modulation method. Then, the DCL-BSC scheme is designed in detail based on the Lyapunov stability theory. And a compensation method based on the phase-shift angle is developed to realize the unity power factor. Compared with the conventional dual closed-loop PI control method, the proposed method has a better steady-state and dynamic performance, and robustness against system disturbances. Simulation and experimental results are used to verify the effectiveness of the proposed control scheme.