The Development Of High Power Isolated Bidirectional DC/DC Converter

With the rapid development of new source technology and energy storage technology,IBDC(Isolated Bidirectional DC/DC)converter has great technical advantages in high-voltage and high-power applications because of its high-frequency isolation and bi-directional flow control.Current domestic and foreign research mainly stay in the theoretical simulation and low-power test prototype of the research stage,for high-power applications in a number of practical problems,especially the most basic safety and stability are less studied.In addition,the dual phase-shifting control strategy can realize the flexible control of the bidirectional energy transfer of the IBDC converter.The implementation of dual phase-shifting control system for IBDC converters is also one of the key technologies developed by IBDC.In this paper,the circuit topology,mathematical modeling and control theory of IBDC converters are studied,and the security and stability of IBDC converters are studied in detail.And a high-power IBDC converter is developed which is safe,stable and flexible.Firstly,the circuit topology and working principle of IBDC are analyzed,the mathematical model of IBDC converter is established,and the control strategy and its superiority are described in detail.Secondly,the problem of IBDC safe and stable operation is studied deeply in practical engineering.According to the IGBT turn-off voltage spike,the causes of IBDC converter 's commutation mode are analyzed,and the design method of stacking busbars and the method of series inductance reactance are adopted.In order to solve the dead band effect caused by the dead band in the middle and high frequency operating conditions,a compensation strategy of bilateral pulse width dead zone for IBDC converters is proposed,which is solved by reasonable compensation of bilateral pulse width.Finally,based on the DSP + FPGA architecture controller,IBDC hardware system and software system are designed,IBDC experimental platform is set up,and the debugging experiment is carried out.The experimental results show that the proposed IBDC converter can run safely and stably,and verify the control characteristics of the IBDC converter under the dual phase-shifted control strategy.