Research On Dual-active Phase-shifted Full-bridge DC-DC Converters

With the severe energy situation in the world and the requirement of people's living environment,the corresponding measures of energy conservation and emission reduction have been paid more and more attention.In the field of new energy generation and electric vehicle,bidirectional DC-DC converter is widely used in charge discharge and energy storage equipment,so it is of great significance to its research.The dual active bridge converter has many advantages,such as high power density,simple control mode,easy to realize soft switch and so on.This makes it receive a great deal of attention in industry and academia.In this paper,the control strategy of the converter is optimized and analyzed in order to solve the problem of high inductance current and high proportion of reflux power in the traditional phase shift control strategy.The problem of large current stress and high power reflux ratio in the traditional phase shifted control strategy is analyzed.On this basis,an optimal control strategy based on dual phase shift and dual dual phase shift is proposed,which takes the inductor current stress and reflux power as the optimization target,the transmission power is the equality constraint condition,and the soft switching of all switches is used as the inequality constraint condition.The MATLAB optimization toolbox is used to solve the optimization problem,which improves the accuracy of the optimization results.The simulation model of the dual active phase shift full bridge converter is established,and the theoretical correctness of the optimal control strategy is verified by the simulation.A dual active phase shifted full bridge converter test platform is built,and the relevant performance of the converter is tested under laboratory conditions.T he experimental results are observed and analyzed to verify the superiority of the proposed optimal control strategy in reducing the current stress and reflux power ratio of the transformer.