A common factor for many applications is the demand for high levels of reliability set against maintenance requirements and/or expensive downtime costs. The complexity of converter systems calls for extensive R&D efforts with the aim of improving component designs and increasing our ability to identify and predict faults. The reliability and ruggedness of power electronic systems can be improved by a better understanding of failure mechanisms and their impact under stressful conditions; by enhancing design, packaging and cooling, and by improving condition monitoring, including fault detection and prediction.
Power semiconductors, currently mostly IGBTs (Insulated Gate Bipolar Transistors), are at the same time the most important and most vulnerable components of a power converter. Rapid technology development means that both failure modes and lifetimes will change as new generations of components are launched. In order to consolidate research into the reliability of power electronics, focusing mainly on power semiconductors, SINTEF Energy Research has joined forces with the Chemnitz University of Technology. Completed and ongoing research projects addressing the reliability of power electronics systems have put us in an excellent position to offer services to industrial companies which we welcome as partners in our ongoing skills-building projects currently looking into power semiconductor reliability.
- We carry out analysis and verification studies using numerical simulations of thermal stress and the efficiency of different converter topologies. Tailored models and tools have been developed to facilitate combined electrical and thermal simulations, permitting accurate predictions of device temperatures in critical hotspots.
- We develop accelerated lifetime test methods for converter components that will be representative of real applications. We also contribute towards the standardisation of such tests.
- We contribute towards the development of robust components, focusing on obtaining stable and predictable behaviour during and after faults, thus reducing converter downtime.
- Based on our experience from existing models, we develop lifetime models for state-of-the-art power semiconductors such IGBTs and SiC devices.
- We are developing a methodology for the online estimation of the remaining lifetime of a given semiconductor device.
- We have installed tailored laboratory equipment called the "Power Cycling Tester" that we use to investigate the failure modes of various power semiconductor technologies and packaging types (modules, press-pack, etc.), including high voltage devices up to 2000A. We also carry out research into the consequences on device lifetime contingent on various stress levels resulting from converter applications.
- One completed R&D project addressing power electronics used in reliable and energy efficient renewable energy systems. (Ref. Offshore Power Electronics - OPE , 2009-2014)
- A new R&D project addressing the reliability and ruggedness of high- power high-voltage power electronics. (Ref. European Consortium on Reliable Power Electronics - ReliPE)
This is a part of our expertise on Power Electronics