The Research On The Three-channel Buck/boost Bidirectional Converter Of Interleaving With Coupled Inductors

It’s a difficult work to design a large power energy storage inductor in bidirectional Buck/Boost converter.In order to overcome this difficulty, this paper studied the interleaving magnetic integration theory of bidirectional Buck/Boost converter. Giving the equivalent steady-state and transient inductors, by taking inverse coupling we can achieve larger steady-state and transient inductors than uncoupled inductors, it will improve Buck converter’s steady-state and transient performances. In which all the phase inductors in3-phase Buck/Boost bidirectional Buck/Boost converter were interleaving magnetic integrated to one coupled inductor. The steady state current ripple and transient current response speed in Buck mode of the interleaving magnetic integrated bidirectional Buck/Boost converter were studied deeply, and the design criterion of the bidirectional Buck/Boost converter was given. With this design criterion, the coupled coefficient of the coupled inductor should be selected with the design formulas and design region proposed in this paper according to the duty cycle and the steady state phase current ripple and the transient total output current response speed when design the bidirectional Buck/Boost converter. In the mean time, designing a no-air coupled inductor structure which adapt to bidirectional Buck/Boost converter "UIII" shaped and variable coupling degree and verify the coupling degree of the coupled inductor to the converter.Finally, The theory was verified with simulation and experimental results.