High temperature capacitor performance in a high power, high frequency converter

Evolutionary increases in the demand on aircraft electrical power systems have resulted in the need to develop the next generation of compact, power dense, electrical systems. These systems will utilize robust and efficient high voltage power devices that are operable over an extended temperature range (-55°C to 250°C). Recent advances in SiC power devices and high temperature magnetic and insulation materials have stimulated the development of compact, high switch rate power system components that can operate at higher temperatures. These efforts have highlighted the need to develop capacitor technology for high power, high frequency power filter applications, which can cycle over a wide range of temperatures. Stacked ceramic and wound polymer capacitors are evaluated as output filter capacitors in a high power, high frequency DC-DC converter from 25°C to 200°C. Experimental data are compared with SPICE simulations and thermal modeling to provide a basic understanding of how the capacitor architecture, its electrical and thermal properties, and thermal stability affect its performance.