Modelling and Simulation of Quasi-Resonant Inverter for Induction Heating under Variable Load

Single-switch quasi-resonant DC inverters are preferred in low-power induction-heating applications for their cheapness. However, they pose difficulties enforcing soft-switching and show limited controllability. A good design of these converters must proceed parallel with the characterization load operating conditions. The control switching frequency has a critical relationship to non-linear behavior due electro-thermal coupling geometrical anisotropies. Finite element methods enable analysis this kind multiphysics coupled systems, but simulation transient dynamics is computationally expensive. goal article propose time-domain strategy analyze induction heating systems single-ended inverter using pulse modulation variable load. estimated through stationary integrated into simulations as equivalent impedance parametrized by look-up tables. model considers variations temperature dynamics, presence work-piece anisotropies, current harmonic waveforms. power regulation based on switch turn-on time tested case study varying it shown that able maintain converter safe operation region, handling up 22% resistance.