The heart of every switched mode converter consists of several switching
semiconductor elements. Due to their non-ideal behaviour there are ON state and
switching losses heating up the silicon chip. That heat must effectively be
transferred to the environment in order to prevent overheating or even
destruction of the element. For a cost-effective design, the semiconductors
should be operated close to their thermal limits. Unfortunately the chip
temperature cannot be measured directly. Therefore a detailed understanding of
how losses arise, including their quantitative estimation, is required.
Furthermore, the heat paths to the environment must be understood in detail.
This paper describes the main issues of loss generation and its transfer to the
environment and how it can be estimated by the help of datasheets and/or
experiments.Comment: 17 pages, contribution to the 2014 CAS - CERN Accelerator School:
Power Converters, Baden, Switzerland, 7-14 May 201
