Test bench for the characterisation of experimental low voltage IGCTs

The paper presents the test bench developed to characterise experimental ABB low voltage IGCTs (3.3 kV) and diodes. Analytical and computer aided tools have been used for designing the test bench components and verifying its operation (hardware choice and control system evaluation). The test bench consists of a power converter applying the opposition method to drive IGCTs at nominal conditions in continuous switching operation (DC-link voltage 1.5 kV, turn-off switching current 2 kA). This method avoids the use of a multi-megawatt power supply to attain the required high power levels (1.5 kV / 40 kW power supply). The aim is to characterise the semiconductors in real operation (switching frequency, cooling system...) as opposed to the classical methods used by power semiconductor manufacturers to characterise their components by purely oscillographic methods (single and double pulse tests, on-state tests). The test bench is instrumented to make the required electrical and thermal measurements necessary for the characterisation of semiconductors and passive components of the test bench. Test results are presented to show the complete characterisation procedure for the semiconductors.