The invention discloses a general transient
DC bias suppression method for a dual-active-bridge converter under bidirectional
power flow. The method comprises the following steps: when the dual-active-bridge
DC converter operates stably, asynchronous carriers are generated; a certain modulation and control strategy is adopted, closed-loop operation is carried out in each switching period, and a primary side inner shift
phase ratio D1, a
secondary side inner shift
phase ratio D2 and an outer shift
phase ratio Df are generated; different working
modes are selected according to the positive and negative relation of the external shift comparison between the current switching period and the previous switching period, and an asynchronously updated modulation wave is generated; and according to the selected working mode, determining a lead and
lag relationship of the modulation wave, comparing the modulation wave with the carrier wave, and generating a driving
signal of a power switch of the dual-active bridge converter. According to the method, the problem that an existing transient
direct current bias suppression method is only suitable for a specific
power flow direction or a specific modulation strategy can be solved, transient
direct current bias suppression under power bidirectional flow is achieved, and
safe operation of the dual active bridge converter is guaranteed.