A Resonant Topology Scheme for Induction Heating to Reduce Power Capacity Requirements

To address the prominent issues of high reactive power and excessive power supply capacity demand in induction heating power supplies caused by strongly inductive loads, this paper proposes a topological compensation method. By introducing an auxiliary resonant network, the method achieves localized autonomous cancellation of the inherent inductive reactive power of the induction coil, thereby reducing the system's demand for apparent power at the source. To validate the proposed scheme, a 3 kW / 85 kHz prototype was developed. Experimental results show that compared to traditional schemes, the system maintains a high input power factor, the required power supply capacity is effectively reduced by over 40%, while low stress on main power devices and high efficiency are preserved. This study provides an effective circuit topology solution for developing next-generation induction heating power supplies with high power density and low cost.