Gate-assisted reverse and forward recovery of high-power GTO's in series resonant dc-link inverters

The series resonant de-link inverter is an attractive circuit topology for interfacing a de current with a three-phase ac system. It uses gate turn-of f thyristors (GTO's) as semiconductor switches, The conventional solution r equires an additional series diode to perform the turn-off process and to e nable forward recovery of the GTO, This paper uses a single GTO along with a special gate drive to provide reverse and forward recovery, A new device testing circuit was designed to create the same electrical and thermal stre sses as in a series resonant de-link inverter. Experimental results rising 2000-A GTO's at 26-kHz switching frequency demonstrate that the total devic e losses are reduced, while the hold-off time is slightly increased. The ne w single-device solution makes resonant switching attractive for very high- power applications.