A Full Duty Cycle Range Soft-Switching High Frequency and High-Efficiency Dual-Buck-ZVT Inverter

The dual buck inverter excels as a highly reliable solution for demanding applications such as aeronautical static converters and traction converters. This is due to its features of no risk of high-frequency bridge-leg shoot-through and independent freewheeling diodes. As these applications evolve toward higher frequencies and greater efficiency, existing dual buck inverters face limitations. Restricted by limited progress in soft-switching (SS) techniques, they currently suffer from low-switching frequencies and the need for bulky magnetic components. These limitations do not align with the evolving demands of these applications. This article proposes a novel single inductor dual-buck-zero-voltage transition (ZVT) SS inverter structure, and based on the SPWM high-frequency modulation with this new ZVT structure, a new dynamic lead time control method is proposed, which helps the ZVT circuit to utilize the auxiliary inductor to transfer the energy to the load and reduces the conduction loss of the ZVT circuit, thus ensuring high efficiency of the inverter during high-frequency operation. This article comprehensively analyzes the control strategy, circuit performance, and parametric design of the proposed dual-buck-ZVT SS inverter, including a detailed investigation of SS region and current stress. To validate the effectiveness of this inverter, an experimental prototype operating at 400 kHz and 1000 W was built. This prototype achieved full duty cycle range SS with a peak efficiency of 97.5%.