Three level single phase half bridge NPCVSI induction heating with combined phase shift PWM and PFM digital power control

Abstract

This paper proposed a combined phase shift PWM and PFM controller of a high frequency three level single-phase half bridge neutral point clamp voltage source inverter (NPCVSI) induction heating application. In heating operation, output power and switching frequency of the inverter are controlled by digital controller to achieve maximum output power and maintain zero voltage switching (ZVS) condition. The microcontroller based digital controller, PI controller, is implemented in a 16-bit microcontroller.