Modeling of Series Resonant Dual Active Bridge with Grid-Connected Inverter for Vehicle-to-Everything Applications

The Vehicle-to-Everything (V2X) application requires a DC-DC converter coupled with an inverter to supply energy demands. Series Resonant Dual Active Bridge (SRDAB) DC-DC converters are gaining popularity owing to their efficiency, miniature size, and high power density. SRDAB is designed to provide a stiff DC source and improve the dynamic performance of three-phase two-level Grid-Connected Inverters (GCI) at the output of SRDAB. These converters are generally time-varying and non-linear because of their switching operation. This paper derives a linear, time-invariant (LTI) model by using generalized state-space averaging. The dynamics are studied by modeling the combined system. The derivation of open-loop models is done analytically, whereas the transfer functions are solved numerically using MATLAB. The bode plots of the derived model and the time-domain simulation using PLECS is compared with each other. A MATLAB/Simulink simulation is done for the combined system with 48 V DC input voltage and 230 V, three-phase AC output voltage to see the effects of disturbances of GCI on the DC link capacitor voltage of SRDAB.