A power control of three-phase converter with AVFSVC control for high-power induction heating applications

This paper presents a three-phase output power control scheme of an induction heating (IH) system using an automatic variable-frequency symmetrical voltage-cancellation (AVFSVC) control technique. The power control is based on the instantaneous output power, filtered and compared with a reference value. The phase angle a is automatically varied depending on the power requirements where the low-power operation is achievable. The high power inverter is operated under zero voltage switching (ZVS) condition by a phase locked loop (PLL) control for maximum overall system efficiency and low switching loss. Calculation and Simulation results are provided in the paper to validate the proposed control method with the output power ranging from 0.024 to 15.63 kW under 15.03 to 16.67 kHz operation frequency.