Gate-assisted reverse and forward recovery of high-power GTOs inseries resonant DC-link inverters

摘要

The series resonant DC-link inverter is an attractive circuitntopology for interfacing a DC current with a three-phase AC system. Itnuses gate turn-off thyristors (GTOs) as semiconductor switches. Thenconventional solution requires an additional series diode to perform thenturn off process and to enable forward recovery of the GTO. This papernuses a single GTO along with a special gate drive to provide reverse andnforward recovery. A new device testing circuit was designed to createnthe same electrical and thermal stresses as in a series resonant DC-linkninverter. Experimental results using 2000 A GTOs at 26 kHz switchingnfrequency demonstrate that the total device losses are reduced, whilenthe hold-off time is slightly increased. The new single-device solutionnmakes resonant switching attractive for very high-power applications