Development of a Coaxial Dual-Coil Induction Heating System With a Composite Bridge-Type Inverter and a Flexible Switching Mechanism

This study proposes a design of the composite bridge-type inverter with a flexible switching mechanism for a coaxial dual-coil induction heating system. Contemporary induction heating technologies predominantly adopt either a single-coil or multi-coil architecture. The former often suffers from limited heating coverage and lacks uniformity, while the latter is favored in applications necessitating broad heating ranges, requiring multiple inverters for effective coil switching control. Consequently, challenges persist in achieving rapid and consistent heating. In this regard, this study proposes a composite bridge-type inverter circuit comprising 5 power components. Through different power transistor switching mechanisms, the system enables independent or simultaneous operation of inner and outer coils, facilitating uniform and swift heating. Furthermore, the proposed inverter can adapt its coil architecture to various operating modes, optimizing heating consistency and performance. Notably, the system achieves an impressive efficiency rate of 96.2%. To validate the viability of our induction heating system concept, a laboratory prototype was constructed and tested. Results from the experiments affirm the system’s flexible switching capabilities, catering to adjustable heating zone requirements in the coaxial dual-coil setup proposed in this study.