| Abstract |
This paper presents the state-of-the-art power electronic developments in a new phase-shift controlled sequential switching-mode voltage-clamped resonant inverter circuit with reactor-storage energy regeneration feedback loops and a constant frequency phase-shifted voltage regulation scheme. The sequential switching voltage-clamped resonant inverter with phase-shift control operates stably and efficiently on the basis of introducing the reverse-blocking thyristors (GATTs), asymetrical thyristors (A-SCR) in series with diode, GTO thyristors, and Static Induction (SI) thyristors for high-frequency switching control. This newly developed sequential resonant inverter with state-variable clamping function can generate stably a large amount of high-frequency AC power in the ultrasonic-frequency ranges from 10kHz up to about 100kHz depending upon the new power semiconductor devices employed, with an improvement in performances and high-power density. The control system implementation of this inverter is demonstrated for induction-heating and-melting applications in industrial and medical systems. The circuit analysis in steady-state is developed and the performance evaluations associated with the phase-shift control voltage regulation characteristics at a fixed frequency and frequency regulation control characteristics are illustrated in terms of the normalized and parameters. The 100kHz-50kW power conversion breadboard and control system hardware, which are put into the practice, are experimentally introduced using high-frequency GATTs which is trially produced for high-performance induction-heating and melting power supply as well as high-intensity ultrasonic generator. |
