Abstract
The bidirectional inverter connected to the grid is a crucial component of DC distribution systems, however its operation can have an impact on the systems' overall efficiency. The usual load profile of such systems in residential buildings is quite dynamic, with multiple periods of light load, especially when compared to high-demand sectors. This study examines and contrasts the impact of SiC and Si power MOSFETs on the best configuration of a 5 kW bidirectional H6 inverter specifically designed for residential use applications. Analytical modeling based on PSIM simulation results is employed to predict losses in a transformer-less synchronous H6 topology. Results of a 5 kW system indicate that silicon carbide (SiC) has an efficiency of up to 98.3%, surpassing the 93.6% efficiency attained with silicon (Si). Furthermore, this study explores potential of further improving efficiency by increasing the operating frequency to 50 kHz. The increase in frequency also leads to a reduction in the size of passive components. The experimental findings of a 1 kW system corroborate the efficacy of the proposed bidirectional synchronous H6 inverter topology, by demonstrating roughly the same trend in terms of the level of improvement over the baseline performance. It has been established that the use of SiC MOSFETs is superior to the use of Si MOSFETs, and that the appropriate operating frequency for bidirectional synchronous and comparable applications is 20 kHz rather than 50 kHz.