Analysis and design of modified half-bridge series resonant inverter with DC-link neutral point clamped cell

In this paper, a modified half-bridge (MHB) resonant inverter topology with DC-link neutral point clamped (NPC) cell is proposed. The proposed topology can maximize inverter output power factor and minimize switching frequency variations. In addition, most of switches are clamped to half of the dc input voltage at turn-off, resulting in increasing overall efficiencies of the system for a wide range of loads. The efficiency of the proposed inverter is improved up to 7% at light load conditions compared with the conventional half-bridge one. Informative expressions for the performance comparison between the proposed inverter and the counterpart are presented. Besides, losses of primary components in inverter are analytically broken down in detail. For the validity, a 120-W prototype is implemented and experiment results are presented.