To solve the problems of large current stress,difficult soft switching of all switches and slow dynamic response of dual active bridge(DAB) converters,a multi-objective unified optimal control strategy based on triple-phase-shift(TPS) control is proposed. The forward power flow global mode of TPS control is analyzed,and three high-efficiency modes are selected to establish the analytical models of current stress and soft switching. Combined with these models,the optimal phase-shift ratio combination and minimum current stress in different modes are derived using the cost function optimization equation,which makes the switches operate within the zero-voltage-switching power constraint range. At the same time,the virtual power component is introduced in the process of efficiency optimization. A small-signal model is constructed,and the influence of small disturbance of different state variables on output voltage is clarified. Experimental results show that the proposed control strategy can not only reduce the current stress of the DAB converter and make all switches realize zero-voltage-switching,but also improve the dynamic performance of output voltage in the full power range.
关键词
双有源桥变换器/三重移相控制/电流应力/软开关/虚拟直接功率控制
Key words
Dual active bridge(DAB) converter/triple-phase-shift(TPS) control/current stress/soft switching/virtual direct power control
维普
万方数据