Research On The Backflow Power Of Bidirectional Full Bridge DC-DC Soft-switching Converter Using Phase-shift Control

With the development of science and technology and the application of new energy, the bidirectional DC-DC converter has been widely applied in the fields of DC Micro Network system, aero power-supply system, Hybrid Electric Vehicle system, energy saving elevator system and so on. The bidirectional DC-DC Converter has become the hot spot of research scholars. This paper selected the backflow power of bi-directional full bridge DC-DC soft-switching converter using phase-shift control as the object of study. The backflow power exists which leads to reducing the efficiency of the converter, increasing the current stress and reducing the range of soft-switching.Firstly, the phase-shift control strategy for bidirectional full bridge DC-DC Converter is analyzed in detail. The viewpoint that there is a certain conditionality between eliminating backflow power and achieving soft-switching proposed when bi-directional full bridge DC-DC converter using phase-shift control is working.Secondly, after analyzing the topology of the bi-directional full bridge DC-DC soft-switching converter using phase-shift control, this paper proposed a topology improved on the topology of full bridge DC-DC soft-switching converter based on immittance network and made a new experimental plan. We can prove that the problem can be solved by using this plan through theoretical analysis and simulation. The problem is that there is a certain conditionality between eliminating backflow power and achieving soft-switching when bi-directional full bridge DC-DC converter using phase-shift control is working.Finally, according to the hardware and software design of the system, the experimental platform has been designed to verify the theoretical analysis. This paper can get the conclusion that the new plan can solve the problem proposed in the above after analyzing the experimental results.