The invention provides a bidirectional DC-DC topological structure, and a bidirectional DC-
DC converter based on the structure. The converter comprises a
coupling inductor L, a
transformer T and switching tubes Q1, Q2 and Q3, and diodes D1, D2, D3 and D4, wherein the two windings Lc1 and Lc2 of the
inductor L have the same turn ratio, the
inductance value is Lc, and the two windings of the
transformer also have the same turn ratio. The bidirectional DC-
DC converter can be applied to a PCU to be used as a BCDR and also can be applied to the fields of all batteries and capacitors and the like which need charging and charging, wherein the converter has four working states: a discharging working state, a state switched from the discharging state to the charging state, a charging working state, and a state switched from the charging state to the discharging state; the
numerical models in the forward and reverse directions of the bidirectional topology are both second-order
minimum phase systems, so that the bidirectional converter can be subjected to parallel control easily; and the bidirectional converter shares the same
coupling inductor in the charging and discharging process, and the second-order
minimum phase systems and the shared same
coupling inductor act together, so that the bidirectional converter has energy bidirectional high-frequency switching ability.