A Weighted Efficiency Enhancement Method for Coupled Inductor Filter-Based H-Bridge Inverters

This article presents a weighted efficiency enhancement (WEE) method for H-bridge inverters based on coupled inductor filter (CIF). The proposed WEE method includes coupled inductor optimization design and switching frequency optimization (SFO) strategy. First, all the energy losses of the H-bridge inverter are elaborated in detail, and the energy loss analysis model of the inverter is constructed based on the dominant energy losses. By installing a CIF on the ac side of the inverter and reasonably selecting the switching frequency, zero-voltage switching (ZVS) is realized for all switches. In addition, an IEEI-type coupled inductor structure and the efficiency-oriented coupled inductor optimization design principle are presented. Then, an SFO strategy is proposed to minimize the total loss of the inverter under full range of loads. Compared with the inverter without the WEE method, the inverter with the WEE method significantly improves the weighted efficiency. Finally, a laboratory prototype is built to verify the validity of the proposed WEE method.