Optimal control of DAB converter backflow power based on phase-shifting strategy

摘要

In order to solve the problems such as high backflow power and current stress of bidirectional DC–DC converter under the traditional single phase-shifting control, an optimized dual phase-shifting control method is proposed. Compared with the conventional phase-shifting control, this method can not only reduce the loss of the converter but also increase the flexibility of the control and realize full voltage range transmission. Firstly, the working principle of dual phase-shifting control and the mathematical model of backflow power are analyzed in detail. Then, the different operating range of return power according to the range of transmission power and voltage transformation ratio are derived. So as to achieve the goal of optimal operation of return power in full mode, the optimal solution of local return power and the corresponding combination of phase-shifting angle are found out. Finally, the superiorities of the control strategy are verified by the experimental results.