FPGA-Based Automatic Frequency-Controlled Resonant Inverter for Induction Heating System

Abstract

This paper presents a frequency tracking control for the half-bridge high-frequency series resonant inverter-fed induction heating system. The aim of this research work is to obtain dynamic zero current switching in the switches of the inverter even under variation in the load. Closed loop frequency tracking control system is developed to track the resonant frequency during step change in load. The change in load is identified by sensing the phase angle between voltage and current. The error in the phase angle is used to track the frequency. Simulation of an open loop and closed loop IH systems has been performed. A simulation study is performed to verify the effect of controller. Simulation results of half-bridge series resonant inverter system with the proposed controller are presented to prove the performance of the developed control system. The results are validated with the prototype of system controlled by FPGA controller.