CHARACTERISTICS OF GTOS AND HIGH-VOLTAGE MCTS IN HIGH-POWER SOFT-SWITCHING CONVERTERS

Presently, high-power soft-switching resonant pole converters, such as the auxiliary resonant commutated pole (ARCP) converter, that have in ternal de link voltages above 1.5 kV, can only use gate turn off thyri stors (GTO's) as main switching devices. For these applications, consi derable effort has been spent to design, evaluate, and enhance the dyn amic performance of high-voltage MOS-controlled thyristors (HVMCT's). It is expected that in the near future HVMCT's, which require little g ate power because of their high gate impedance, will gradually replace high-voltage GTO's. The purpose of this paper is to present and summa rize key HVMCT characterization results gathered to date as they relat e to their dynamic performance during zero-voltage switching. HVMCT de vices capable of turning off 300 A and withstanding 3000 V are present ed. The paper concludes with a comparison of the soft-switching perfor mance of HVMCT's and GTO's in an ARCP converter phase leg.