Investigation on the short-circuit behavior of an aged IGBT module through a 6 kA/1.1 kV non-destructive testing equipment

This paper describes the design and development of a 6 kA/1.1 kV non-destructive testing system, which aims for short circuit testing of high-power IGBT modules. An ultra-low stray inductance of 37 nH is achieved in the implementation of the tester. An 100 MHz FPGA supervising unit enables 10 ns level control accuracy of the short-circuit duration, protection triggering, and acquisition of the electrical waveforms. Moreover, a protection circuit avoids explosions in case of failure, making the post-failure analysis possible. A case study has been carried out on an aged 1.7 kV IGBT power module. The case study shows the current and voltage waveforms during short-circuit, as well as the current mismatch among six inner sections, which demonstrate the capability and the effectiveness of the proposed setup in the short-circuit aspect reliability studies of MW-scale power modules.