Pulse converter for induction-heating applications

A novel pulse-current converter topology for induction heating is introduced. The possibility and expediency of the pulse current for induction heating have been demonstrated. The converter comprises the input filter, input reactor, bridge rectifier, two power switches, two coils mutually coupled with the input reactor and the heating inductor (load), where the output power is controlled by a switching frequency. The steady-state analysis of the converter operation, its computer simulation and the experimental verifications on the converter model have been performed. The simulation on the computer and the experimental results are shown to be in good agreement with the theoretical results. The following two goals have been achieved: (a) the analysis of the heating process with the pulse current has been performed; and (b) the appropriate scheme of the pulse-current supply has been developed. The proposed scheme fulfills the requirements of modern power supplies: sine form of the input current, unity power factor, soft commutation and a wide range of output power. The proposed configuration can be used for heating, annealing, melting and hardening in the power range of 250–300 kW.