25kW/L 99.2% Efficiency Wide Output Three-phase PFC based on Modular Inductive Switching Network

Abstract:
The modular inductive switching network (MISN) converter, with its modular design and single DC bus, offers a promising solution for high efficiency and power density AC-DC conversion. However, in applications involving battery charging that require a wide range of DC bus voltages, the MISN module experiences significant increases in loss and volume. This study develops a mathematical model to analyze the impact of DC bus voltage on the MISN module, with particular attention to loss and volume. It is founded that the operating voltage and buffer energy of the MISN module grow as the DC bus voltage range expands, resulting in higher switching loss and larger capacitance volume. To address these issues, a new MISN-PFC converter with 3level LF-bridge is proposed, which has lower voltage stress of the MISN module. Experimental results from a 10 kW prototype operating over a DC bus voltage range of 550V to 900V demonstrate a full-load efficiency of 99% and a power density of 25kW/L, outperforming conventional designs with 2level LF-bridge.