Scalable open- and balance-type calorimeter for measuring power electronics and motors

Accurate measurement of losses of high-efficiency power electronics devices and electrical motors is difficult by using input and output powers. In the calorimetric method, these losses are measured directly. However, the calorimeters have to be designed for a certain power loss range, and therefore, the same system cannot be applied to different power devices. In this paper, a functional and scalable power loss measurement concept is suggested for the measurement of losses between 10 W and 30 kW with a reasonable measurement accuracy. Such a power loss range can be applied, for example, to devices with 97% efficiencies with input powers between 333 W and 1 MW. The concept is introduced, verified, and demonstrated by laboratory measurements.