Temperature-Controlled Power Semiconductor Characterization Using Thermoelectric Coolers

Accurate characterization of power semiconductors over wide operating ranges is a necessity to accomplish better electrical and thermal designs of power converters. Especially, switching losses of power devices are rarely given sufficiently detailed in their datasheets, since they also depend strongly on the driving circuitry and design of the power converter itself. A means to extract the switching losses are double pulse measurements where the desired operating points can be freely chosen. This paper introduces a temperature conditioning unit that allows the adjustment of the junction temperature between −40 °C and 200 °C using thermoelectric coolers (TECs). The unit is for an automated double pulse test bench with dc-link voltages of up to 1 kV and switching currents of up to 1 kA. Up to 1 kW of electrical power is required to power the TECs. The design of the power converter is shown as well as the control scheme. An algorithm, which automatically extracts the switching losses of the measured double pulse waveforms is presented. An exemplary characterization of an Infineon EconoDual power module is conducted and the results are presented.