Novel thin heating coil structure with reduced copper loss for high frequency induction cookers

Litz wire has been widely utilized for heating coils of high frequency induction cookers. However, these coils often suffer from large winding height due to low space factor of Litz wire. Certainly, rectangular wire may reduce the winding height of the coil owing to its high space factor. However, the rectangular wire tends to suffer from large copper loss caused by the skin effect and the proximity effect. In the conventional coil structure of the rectangular wire, these effects cause concentrated AC current distribution, which leads to excessive copper loss. This paper addresses this issue by proposing a novel heating coil structure of the rectangular wire that can homogenize the AC current distribution. This paper also presents the simulation results that successfully verified the effectiveness of the proposed structure.