Self-protection systems for domestic induction heating based on ferromagnetic materials with low Curie temperature

In cooking processes, regardless of the technology used (glass-ceramic, induction or gas), it is necessary to have a protection system that can prevent the cooktop from burning in case of forgetting or abandoning the cookware during the process. In this paper it is presented a design of a self-protection system against over-temperatures, for domestic induction heating applications, based on electrical measurements. It is proposed the fabrication of cooking vessels using materials with electro-magnetic properties that change with a predefined temperature and whose changes can be detected with the current induction cooktops on the market. The use of this method does not require any additional sensor, as opposed to other systems that use different types of sensors to detect the temperature, which would reduce the complexity and costs of the induction cooktop. The different materials and designs proposed for use in cooking vessels have been experimentally tested and it has been defined an impedance threshold value, to be implemented in the control system, for which the system can consider that the safety temperature has been exceeded.