Analysis and Design of Flexible-Surface Induction-Heating Cooktop With GaN-HEMT-Based Multiple Inverter System

The flexible induction cooktop, which can provide an unlimited cooking area, utilizes a cost-effective method in which one inverter shares multiple working coils. However, this method has resulted in consumer needs such as reducing both the initial pot detection time and the noise caused by the relay operation. This article presents a hardware implementation and control method for a flexible induction cooktop with multiple GaN-HEMT-based inverter systems. As one way to meet consumer needs, this implementation method does not require a relay and offers the advantage of real-time pot detection and noise minimization. However, the inverter design should include the magnetic coupling effect while maintaining high performance and high power density. This article proposes an inverter design method considering the limited space and an implementation method that minimizes the effect of magnetic coupling without an additional power stage. The feasibility of the proposed implementation method is evaluated based on the results of a heating test with a 3.3 kW prototype.