A System for Thermal Model Verification of a Power Switch

In order to verify a numerical thermal model for IGBTs (insulated-gate bipolar transistor), a measurement and control system was constructed and it is presented in this paper. It is based on a commercially available frequency converter which is modified and controlled by a dSPACE system. The galvanic isolation is achieved using optic cables in the control and measurement of the converter. The temperature of the IGBT chip in the converter is measured with a K-type thermocouple. The thermal model is run on-line in the dSPACE, and it uses the switching commands and the measured output current as inputs. The load of the converter is a simple LR-circuit. It is shown that the introduced method can be used to verify a thermal model