Design of an advanced modular automated evaluation system for experimental high power Si and SiC SGTOs

An advanced evaluation system for experimental high power silicon (Si) and silicon carbide (SiC) Super Gate Turn Off Thyristors (SGTOs) with custom data acquisition and characterization electronics was designed and built in a cooperative agreement between engineers at Texas Tech University´s (TTU) Center for Pulsed Power and Power Electronics (P³E) laboratory and research scientists at the U.S. Army Research Lab (ARL). The system consists of a 4.4 kJ Pulse Forming Network (PFN) energized by a 10 kW rapid capacitor charger developed at TTU, a data acquisition system which records chosen waveforms for each test cycle and a curve tracing module which the test devices are mechanically switched into to record current and voltage characteristics at arbitrary intervals between high power cycles. Testing is completely automated, with all test parameters including charge level, repetition rate, volume, etc. set within a custom windows based GUI. The evaluation system has successfully recorded changing I-V characteristics before actual physical failure in several devices. Extremely high volume testing has also been carried out with one device having been cycled over 30,000 times at moderate (2.5 kA) conduction levels. This paper expands on work presented at the 2012 Power Modulator Conference and presents newly acquired data and modifications.