All-utensil domestic induction heating system

Abstract

This paper proposes and implements an all-utensil domestic induction heating system, which can effectively heat utensils made by ferromagnetic conductive (FC), non-ferromagnetic conductive (NFC) and non-ferromagnetic non-conductive (NFNC) materials. The proposed system consists of a controller, a full-bridge inverter and a new sandwiched-coil structure with the primary coil located at the lower part, ferrite bars in the middle part and resonant coil in the upper part of the heater, respectively. Besides, a fixed capacitor is connected with the primary coil and a switched-capacitor array is connected with the resonant coil to ensure that the magnetic resonant coupling (MRC) can be achieved when adopting different utensils. The proposed system not only releases the current stress of the inverter but also significantly strengthens the magnetic coupling effect to boost the heating performance under a resonant frequency of 30 kHz. In the meantime, the burst firing control (BFC) is utilized to flexibly regulate the output power while retaining the maximum transfer efficiency. For exemplification, a 500 W prototype has been built for heating FC (iron), NFC (aluminum) and NFNC (ceramic) utensils with the average temperatures of 83.8, 73.1 and 76.5 °C, output powers of 484.4, 411.4 and 426.16 W, and transfer efficiencies of 96.9, 82.3 and 85.2% respectively. Both finite element analysis and experimentation are given to verify the validity of the proposed system.