Dimensioning of power semiconductor devices in their unnatural environment

Power diodes, high power thyristors, gate turn-off thyristors (GTOs) and IGBT modules are the main power switches widely used in the industries today. Therefore it is important that ratings and characteristics are well understood before these devices are designed in the systems. Operating devices within the data-sheets limits assures safe and reliable operation of devices, however some applications such as pulsed power fall outside the natural applications limits for which the devices are originally designed. Therefore dimensioning these devices outside their normal application area becomes somewhat difficult. In this paper we introduce a methodology where by electro-thermal device models are created from the datasheet information which can be used in conjunction with spreadsheet to calculate the maximum junction temperature for reliable operation of power devices under abnormal conditions.