通过对比各类DC/DC变换器的拓扑特点，选取电源和变压器利用率高，功率密度高的隔离型双向桥直流直流变换器（BDC）；为提高电压增益和能量传输效率，改进为谐振型BDC；为实现双向工作特性一致和软开关功能，进一步改进为CLLC谐振型BDC；为实现频率偏移下恒定的电压增益和传输效率，最终设计出频率跟踪的CLLC谐振型BDC。仿真结果表明，所设计的频率跟踪的CLLC谐振型BDC在大频率范围偏移下，无论是正向传输，还是反向传输，都能保持很高的电压增益和能量传输效率，而且双向传输特性基本一致。

By comparing the topological characteristics of various DC/DC converters, an isolated bidirectio nal bridge DC/DC converter （BDC） with high power supply and transformer utilization and high power d ensity is selected; in order to improve the voltage gain and energy transmission efficiency, the resonant t ype is improved. BDC; in order to achieve consistent bidirectional operating characteristics and soft switc hing function, it is further improved to CLLC resonant BDC; in order to achieve constant voltage gain a nd transmission efficiency under frequency offset, a frequency tracking CLLC resonant BDC is finally de signed. The simulation results show that the frequency-tracking CLLC resonant BDC designed in this pap er can maintain high voltage gain and energy transmission efficiency under a large frequency range offset, no matter it is forward transmission or reverse transmission, and the bidirectional transmission characteris tics are basically Consistent.