Dealing with uncertainty in power loss estimates in thermal design of power electronic circuits

Abstract

Thermal analysis is critical in the conceptual design phase of miniaturized power electronic circuits. Concurrent thermal and packaging design along with electrical design can ensure shortened time-to-market. However, uncertainties in estimates of component loss distribution in the early design phase hamper analysis of whether a proposed design will meet thermal specifications. In this paper, a methodology based on design of experiments (DOE) is proposed to deal with such uncertainties. By combining this methodology with a thermal analysis tool, uncertainties in individual component loss estimates can be translated to predicted temperatures with a minimum number of computational runs. The designer can also use the sensitivity coefficients generated as a result of such analysis to judge the effect of efficiency improvement in individual components on the overall temperature field. An example of the thermal design of a power electronics circuit is provided, where this method has been used to study various design trade-offs and to significantly reduce the design cycle.