Temperature Estimation Techniques of a Pot through Real-time Impedance Measurement of an Induction Heating System

Abstract

Recently, induction heating (IH) technologies are widely applied in home cooking appliances due to characteristics such as fast heating, energy-saving, and high efficiency. In the IH systems, load impedance variations depend on switching frequency, pot material, operating temperature, and alignment between the pot and the induction coil. The pot's temperature estimation using the impedance measurement of the resonant network can be used to improve the efficiency of the IH system and to make the IH cooking safe without additional temperature sensors. In this paper, a time-split method is proposed to measure a real-time impedance and to estimate the pot's temperature by using the regression model of the impedance. The proposed temperature estimation technique is verified using a 2-kW series resonant inverter prototype.