A multi-level bi-directional buck-boost converter using GaN devices for electric vehicle applications

A modular multi-level bi-directional diode-clamped DC-DC converter based on enhancement Gallium Nitride (eGaN) High Electron Mobility Transistor (HEMT) is proposed as a plugin charger for electric vehicles (EVs). The eGaN HEMT can switch efficiently even in hard switching, but their problem is that they cannot tolerate voltage stresses higher than 650V. The proposed multilevel topology reduces the voltage stress across the switches which enables utilizing eGaN HEMT technology in the powertrain of the EVs. Simulations were carried out in PSpice environment using the eGaN equivalent circuit provided by the manufacturer. The simulation results prove that the performance of the proposed converter complies with the theoretical analysis.