Circuit design and experimental test of a high power IGBT non-destructive tester

The study proposes the design and transient analysis of an IGBT non-destructive tester. The tester is designed to test IGBTs at voltage and current ratings less than 3.3 kV 2.4 kA. Due to stray elements, the circuit might oscillate during the different modes of operation and test conditions. These oscillations could cause high stresses to the IGBT switches in the circuit and cause one or more of the switches to fail. A transient analysis is performed taking into account the different operating conditions. Hence the potential for destructive oscillations can be minimized via the proper design of the IGBT gate resistors. An analogue controller, based on voltage collapse detection after turn off failure, is designed and developed. Simulation results of a failure case study using spice simulation software are then presented. Finally, experimental results are presented demonstrating failure detection and protection of the device under test.