Control Strategies and Design Guideline for Single Phase MISN PFC Converter

Abstract

The increasing demanding for high efficiency and high power density power supply motivates the application of multilevel converter in server power supply and on-board charger, particularly flying capacitor (FC) and cascaded H-bridge (CHB). Nevertheless, considering the good modularity, single-port structure, and compact size, the existing schemes fall short of meeting the requirements. In this article, a single output-bus multilevel power factor correction (PFC) converter with modular inductive switching network (MISN) is proposed, which constructs with multilevel MISN and line frequency bridge (LF-bridge). The MISN PFC converter resolves the multi-port issue of CHB while maintaining a superior modular structure, which is conducive to redundancy protection. The control strategy for MISN PFC converter is analyzed and designed to guarantee the voltage stability of MISN. Additionally, to eliminate inductor current distortion when the LF-bridge switches, a transient compensation control is proposed and integrated into the control system. Furthermore, the design guideline on the output voltage, the operating voltage, capacity, cell number and switching frequency of MISN for achieving high efficiency and high power density is provided. A single phase 3kW prototype is built up to verify the analysis, achieving a 99.2% peak efficiency and 700 W/in³ power density.