A Direct AC-AC Multiple Load Inverter for Vessels of Different Materials

Induction heating (IH) systems are emerging as an alluring solution to the domestic heating appliances market. Heating multiple loads and loads of different materials is often required. It is challenging to heat ferromagnetic as well non-ferromagnetic materials simultaneously due to their different heating requirements. Classical IH solutions consist of two power conversion stages which reduces the overall efficiency of the system. In order to overcome this, a direct ac-ac multiple load inverter for different materials is proposed in this paper. Dual frequency approach is used to meet different heating requirements of the ferromagnetic and non-ferromagnetic material loads. Asymmetric duty cycle control (ADC) is used to obtain independent control of each load. The performance of the proposed direct ac-ac multiple load inverter is verified by simulations in MATLAB/Simulink environment.