Calorimetry for Power Electronics

Calorimetry allows direct, accurate measurements of losses in power electronics systems. A small-scale version of a double chamber, closed type calorimeter for measuring losses up to 20 W is described in this paper. The design comprises an inner chamber with heat exchangers integrated into the top and bottom of the chamber, surrounded by insulation. This is enclosed by a temperature controlled air gap, within a further insulated enclosure. Calibration tests show that losses can be measured to a precision of +/- 0.4 W and ways of improving the accuracy further are discussed