Design, Simulation and Implementation of a 60kW Variable Voltage DC Power Supply for a Current-Fed Parallel Resonant Inverter used in Induction Heating Applications

Abstract

This research deals with the design, simulation and Implementation of a 60kW variable voltage, current source, DC power supply suitable for induction heating purposes composed of three-phase fully controlled full-wave rectifier (3-Ph FCFWR) with a smoothing reactor. It is suitable to supply a current-fed parallel inverter (CFPI) frequency converter (built on Transistors), feeding a high quality factor resonating induction heating load. Such a source must verify two main objectives for achieving safety start up, those are: (a) achieving an aperiodic dynamic behavior during starting, since it may result in overvoltage across different elements of the converter, (b) assuring continuous current mode operation to achieve safety start up. A high inductance smoothing reactor is usually connected with the input of the inverter to perform these objectives. In this research the theoretical derivation is modified to reach the suitable formula to determine the value of the self-inductance of the smoothing reactor for the required power supply. Also, the smoothing reactor is designed and implemented. The designed power supply is simulated using (MAT LAB) package. The practical measurements of load voltage and current waveforms at the starting angle of the implemented power supply satisfying the above two main objectives and are in a good agreement with the simulated waveforms at that angle.