Power loss measurement based on transient temperature rise

A calorimetric method for the determination of losses by means of transient temperature rise is applied to a basic switching cell. The method generally offers a very short measuring time in combination with high accuracy. However, an appropriate characterization of the set-up is crucial which usually implies a large effort. Hence, a simplified thermal model is introduced which minimizes this effort while still obtaining a high accuracy. In addition an elaborate but easy to use calibration and determination procedure is proposed. The result is a power loss measurement method based on calorimetry with a degree of accuracy which could be hardly reached by an electrical measurement. In comparison to common calorimetric methods the measurement time can be dramatically reduced. The method is used to verify predicted losses of a PFC boost converter.