Thermal modeling of high temperature power conversion capacitors

As an enabling technology, the state-of-the-art for wound film capacitors is continuously being driven towards higher temperature, higher energy density, and longer life to support the development of tomorrow´s advanced systems. Progress in high temperature capacitors, defined in this work as a capacitor operating at temperatures at or above 100°C, is particularly important as system developers seek to reduce weight and size by removing cooling equipment for electronic components. This temperature regime is extremely strenuous for polymer wound film capacitors since all but the most expensive and specialized dielectric materials are greatly weakened electrically and mechanically. Capacitors designed to operate under high frequency (30 kHz) and high RMS current values undergo even more strenuous conditions and require special consideration in their design. In addition to ambient temperature, the heat generated by high frequency operation can decrease the lifetime of the unit and is of concern to both the designer of the component and the system it is used in. This work investigates the thermal behavior of high temperature, high frequency capacitors with the intent of assisting both component and system designers.