A measurement apparatus for switching losses based on an heat-flux sensor

The measurement of the power dissipated by a semiconductor device is essential to evaluate the performance and reliability of the device itself and those of the whole power electronics system. When measuring the efficiency of an electronic system, measurement errors can be introduced by the probes or by instruments due to high frequency components in the waveforms. Efficiency measurement can therefore be difficult when the device is highly efficient and the power losses are extremely low and the use of bulky and expensive set-up´s is often required. The paper present a simple method based on a heat-flux measurement sensor that allows the estimation by calorimetry of the power dissipated by a semiconductor device. The system uses a Peltier heat pump and a control/readout circuit to keep the switching device at room temperature and minimise the heat exchanged with the ambient, improving the accuracy of the measurement.