Power converters and systems

Profile

In power electronics, we are active on various levels in the system hierarchy:

On component level, we are looking into power semiconductors of different materials as GaN, SiC and Si. By the standard understanding of their static and dynamic behaviour, our research focus is on understanding and prediction of failure mechanisms and failures. Therefore, we use electrical and optical methods to compare their characteristics before and after the ageing. The ageing itself is done for different scenarios as power cycling, short circuits, thermal cycling and in the field. Based on the findings, general lifetime prediction for the semiconductors especially for SiC and GaN devices will be developed.

On device level (power modules), we are investigating and optimising the die attachment and the bonding with respect to parasitics and the interaction with the gate driver.

On system level, we are looking into different topologies that are suitable for relevant applications and apply the modern semiconductors. Here also cooling concepts and the interaction with the passive power semiconductor are investigated and improved.

For the future also the new opportunities deriving from internet of things for power electronic systems will be investigated. The starting point will be most likely failure prediction based on actual load profiles and sensing of relevant values.

Services

Test & measurement

• Characterisation of power semiconductors and modules
• Power cycling test
• Temperature cycling test
• Highly accelerated lifetime test (HALT)
• Efficiency measurements (electrical, later also calorimetric)
• Characterisation of passive components

• Failure analysis
• Reverse engineering
• Technology clarification and experts report

Labs and Equipment

• Machine lab for testing drives in interaction with the machine and to test motor designs
• Reliability lab incl. shaker, climate chambers, power cycling microscopy and X-ray
• Power semiconductor lab incl curve tracer and double pulse tester
• Capacitor and inductor lab incl. high power LCR meter, tester to characterise passive to components
• Power stack lab incl. back to back water- and air-cooled tester up to 1 MW