Operation Range Extension Method of DAB Converter Considering ZVS Condition Using Core-Insertable Transformer with Variable Inductance

This study proposes an output operation range extension method for a dual-active-bridge (DAB) converter using a core-insertable transformer with variable inductance considering the zero-voltage switching (ZVS) condition. In a DAB converter, the inductance is a crucial factor that determines the power transfer and is associated with the output range and ZVS condition. If such an inductance can be varied a wide range of loads can be used considering the ZVS condition and the operating characteristics can be improved. The proposed method presents variable inductance based on the condition under which a core is inserted into the transformer. The proposed method was validated through the variation in the leakage inductance based on the core insertion condition, and the simulations and experimental results within the inductance variable range.