A comparison between single-stage and dual-stage high-gain GaN dc/dc converters for Li-Ion battery modules

For building Li-ion battery energy systems (Li-ESS), series and parallel arrangements of Li-ion modules are used to increase voltage levels and energy capacity, respectively. Use of Li-ESS in stationary applications usually requires to boost the battery terminal voltages to the needed voltage levels at the inverter stage, which is typically 400 V and 800 V in single-phase and three-phase applications, respectively. For grid-tied applications, often galvanic isolation is required. This paper compares two single and dual-stage isolated bidirectional converters used for boosting a 48 V battery module to 400 V at a maximum power of 20 kW. Both topologies are implemented using GaN-HEMT semiconductors for the converters’ power stage. Special attention will be paid regarding the switches and driver selection as well as the parallel operation of the power switches. Simulation results are used for the validation of the proposed design.