Terminal sliding mode control for dual active bridge dc-dc converter with structure of voltage and current double closed loop

Abstract

Traditional PI controller for dual active bridge dc-dc converter has slower response speed and worse steady accuracy. Terminal sliding mode (TSM) control method with structure of voltage and current double closed loop is proposed. The unified differential equation model of the converter for the case of switching ON/OFF was established based on kirchhoff's law and a TSM controller and LSM controller was designed for the outer capacitor voltage subsystem and output current for H bridge on the secondary side of the transformer respectively to guarantee the transient performance and expected DC voltage output in the finite time. Meanwhile, the unified stability condition of DAB converter for the case of switching ON/OFF was deduced by the existence condition of sliding mode control. Simulation validate the accuracy of the design.