Phase-Locked Loop-Based Asymmetric Voltage Cancellation for the Power Control in Dual Half-Bridge Series Resonant Inverter Sharing Common Capacitor for Induction Heating Applications

This work aims at suggesting a frequency tracking system for a dual half-bridge series resonant inverter applied to induction heating (IH) system. The modulation technique incorporated is asymmetric voltage cancellation method. In this new tuning method, the control range is enhanced to the whole range of inverter operation. Also, the inverter discussed here is capable of driving two (dual) loads simultaneously compared to the conventional inverter feeding single load. Small-signal modeling of the dual-load IH system is discussed in this article to facilitate stability and controllability of the IH load. Also, the power control margin is determined with the necessary pole-zero plots. The simulation study of the proposed system is incorporated in the MATLAB/Simulink and also experimentally validated for the dual-coil induction cooking system.