Fixed frequency mode phasor-shifting power control ZCS high-frequency inverter for induction heating using SI devices

This paper presents a new circuit configuration of resonant type high-frequency inverter using SI devices having inherent fast response of the output power regulation and variable voltage under constant frequency mode. The proposed high-frequency resonant inverter circuit is composed of a half-bridge topology of two series-resonant sub-circuits with common DC input power source, which can operate at a zero-current soft-switching (ZCS) mode over the wide load range in the power regulation process. The trially-produced new resonant prototype inverter using bipolar-mode static induction transistor (B-SIT) is originally tested with a high-frequency induction-heating load with parallel tuned tank circuit to demonstrate experimentally the proposed instantaneous current-phasor controlled inverter principle and the steady-state inverter performances