Soft-stop optimal trajectory control for improved operation of the series resonant multi-inverter

Induction heating technology is leading technical advances in home appliances due to the benefits inherent to the contactless energy transfer including high efficiency, fast heating, safety, cleanness and accurate control, among others. Recent advances are aimed at developing more versatile cooking surfaces for a superior user performance. In order to achieve such designs, new multiple-output power converters must be developed. The series resonant multi-inverter has been proposed as an efficient, versatile and cost-effective alternative to supply multi-inductor systems. However, several design challenges must be faced, including the required high blocking voltage of power devices, which may compromise the converter performance. This paper proposes an optimized modulation strategy to reduce this voltage, enabling an optimized converter design with improved reliability and performance. The proposed modulation is analytically studied and tested using an induction heating converter prototype, proving the feasibility of this proposal.