GaN-Based MHz Single Phase Inverter with a High Efficiency Hybrid TCM Control Method

Triangular current mode (TCM) control for single phase inverters leads to significant improvement in efficiency at high switching frequencies. However, the huge switching frequency variation of the TCM-based inverter leads to excessive turn-off switching loss, as well as excessive core and winding losses of the inductor. For achieving better performances of TCM-based inverter, a hybrid TCM control is proposed for switching frequency limitation and maintaining high efficiency. An optimization algorithm is established for maximizing the efficiency of the hybrid TCM control. Based on an analytical loss model of GaN HEMTs in this optimization algorithm, the optimal control strategy can be determined. The results show the efficiency with optimal hybrid TCM control is higher than pure TCM operation at light loads. Finally, the proposed hybrid TCM control is verified in an interleaved GaN-based MHz single phase inverter.