A soft switching class D current source inverter for induction heating with non-ferromagnetic load

A class D current source resonant inverter (CSRI) with interleaved buck converter for induction heating power supplies for non-ferromagnetic load is proposed in this paper. The switching devices of CSRI are connected through the common ground and only a single dc power supply is needed for the gate driver circuitry. The maximum output power transferred to the load for the hardware prototype is 1.26 kW. The resonant inverter operates at a fixed frequency of 108 kHz while the interleaved buck converter operates at 40 kHz for soft-switching operation. The output power is controlled by adjusting the pulse width of the interleaved buck converter. The hardware prototype is capable for melting a 30-gram aluminum workpiece at 700 degree Celsius within 25 minutes.