Voltage balancing control of IPOS modular dual active bridge DC/DC converters based on hierarchical sliding mode control

Abstract

This paper proposes a novel nonlinear control method for the input-parallel output-series modular dual active bridge (DAB) dc/dc converter which regulates the dc-bus voltage and individual module voltages together. At first, a state space form of the DAB converter model is derived. Next, the output voltage controller of the modular DAB converter is designed with the hierarchical sliding-mode control theory. Furthermore, due to the robustness of the sliding-mode control, the control performance is insensitive to the mismatch of leakage inductances of the DAB transformers. The feasibility of the proposed control scheme has been proved by simulation and experimental results.