Testing of a 470 ampere RMS 2000 volt regenerative gate turn-on thyristor

The Army's requirements for new concepts in land mobile power converter systems includes electrical power conversion equipment suitable for propulsion and precision power. However, cost effective power conversion by electrical means is dependent upon the availability of reliably performing thyristor switching devices. Some of the thyristor performance criteria are switching speed, blocking voltage and hard pulse current sustaining capability at high repetition rates. These qualities seemed to be combined in the "Regenerative Gate Turn-On Thyristor," thus warranting a full evaluation concerning the performance characteristics of the device. This paper discusses general thyristor design problems and subsequent improvements in the state-of-the-art device performance by applying the principle of the "Regenerative Gate Trigger" to thyristor design (1,2). Extensive testing of a 470 ARMS, experimental regenerative-gate triggered thyristor shows that this device is potentially suited for a 1 Megawatt high speed energy transfer at elevated temperatures and is capable of blocking up to 2000 volts. The experimentally obtained and calculated data demonstrate that the device has maintained an unusually hard current, pulse switching capability despite its high frequency characteristics and interdigitation, formerly reserved only for the diffused alloy constructions. The device is of such rugged design that its actual switching capabilities and limits could not be established at the time because of basic limitations in available thyristor test equipment. The current interest in high speed thyristor switches, and the need to obtain performance data from these devices, has resulted in a government funded development program and in independent industrial design of a new generation of test equipment. Two thyristor testers are described in order to demonstrate that modern test equipment is available leading to a new generation of thyristor specifications in the immediate future.