Moving Discretized Control Set — Model Predictive Control for Dual-Active-Bridge with Triple Phase Shift

Triple-phase shift (TPS) is commonly utilized to enhance the efficiency of the dual-active-bridge (DAB) converters. However, the small-signal model of the circuit varies with operating mode, terminal voltage ratio, and power. In order to address this issue, a control inspired by the finite-control set model-predictive control is proposed. The proposed moving discretized control set model-predictive control (MDCS-MPC) can achieve great control flexibility and good transition performance throughout the power and terminal voltage range with global control parameters. It presents fixed switching frequency with low computational burden due to the utilization of only two prediction horizons. The operating principle of the proposed MDCS-MPC is introduced in development of a cost function that provides stiff load voltage regulation. The steady-state error in MDCS-MPC has also been analyzed and compensated. The application of MDCS-MPC in a multiobjective control scenario has been addressed. Experiments on a 300-V/300-V 20-kHz 1-kW DAB converter are carried out to verify the theoretical claims.