300C ferrite material for high temperature magnetics

The next generation of power electronics is likely to use high temperature capable silicon carbide semiconductors. To fully utilize the capabilities of these devices, high temperature magnetics and other passive components will be required. A 300C ferrite material has been developed to operate at over 300 degree C combined ambient and rise. Presently available ferrite materials have Curie temperatures of 250°C or lower and are optimized for use at temperatures of 100°C or less. This paper will discuss ferrite power materials developed by magnetics for use at frequencies above 200 kHz and temperatures of 300°C. An evaluation of this material has been performed using a 1.5 kW, 270 Vdc to 28 Vdc converter. Both test data and analysis are presented to show the material capability and techniques for fully utilizing the high temperature capabilities of the ferrite material. The test data and analysis includes a discussion of various winding and high temperature insulation techniques consistent with high voltage and power electronics high frequency magnetics issues. This program is being conducted under an Air Force Research Lab (AFRL) contract.