Inverse-Based Power Control in Domestic Induction-Heating Applications

The wide variability of the load is the main problem of domestic induction-heating technology. The considered power control strategy should guarantee stability and regulation with a suitable response time and no overshoot independently of any perturbation or load variation. In addition to this, it has to ensure the operation under safety conditions. This paper is focused on the power control applied to one heating unit by means of continuous modulations. An inverse-based power controller is proposed for dealing with load uncertainties. The proposed power control combines different variable frequency pulsewidth modulation strategies (constant duty cycle, constant on-time, and constant off-time modulations) for reaching the target power level while minimizing the switching frequency. Finally, simulation and experimental results compared with other techniques in a prototype of an induction-heating system are presented in order to validate the proposed control strategy.