Application of a new power-based control method for induction cooking systems

In resonance inverters used in induction heating systems, maximum power transfer occurs when the switching frequency is equal to the resonant frequency. The impedance of the induction cookers constantly changing according to the type and position of the pots and the power transfer problem accordingly constitute a serious problem. In this study, the Frequency Tracking Maximum Power Transfer (MPTFT) algorithm was developed in order to transmit maximum power in induction heating systems, and switching at a frequency very close to the resonant frequency was ensured under varying impedance conditions. Due to its full compatibility with control algorithms, full bridge series resonance inverter topology was preferred in the thesis. In order to control the output power, a DC/DC Buck converter circuit has been preferred at the inverter input, and a Proportional-Integral (PI) controller has been used to control the duty cycle of the switching element and thus the DC-Bus voltage control has been performed. Simulation analysis of the designed system; Matlab/Simulink and ANSYS/Maxwell 3D FEM were modeled environment and simulated. In the experimental application, FPGA control card was used due to its fast operation capability and a 1 kW system was designed and the simulation results and the application results for two different pots were compared. As a result of the comparisons, it was observed that the experimental application results were compatible with the Matlab/Simulink and ANSYS/Maxwell 3D simulation results. Keywords: Induction heating and cooking, Maximum power transfer method, Maximum power transfer (MPTFT) algorithm with frequency tracking, FPGA, ANSYS/Maxwell 3D