AFRL Incorporates Turbogenerator Into Integrated Cooling and Power System Published Dec. 4, 2007 By Propulsions Directorate AFRL/RZ WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- Engineers from AFRL and industry partner Smiths Aerospace successfully demonstrated the use of a turbogenerator in an integrated cooling and power system (ICPS) to provide extra power and cooling. This generator supplies additional power and cooling for aircraft that have no remaining margin for new electronics. Driven by engine bleed air, the turbogenerator simultaneously delivers dedicated high-frequency alternating current (AC) or direct current (DC) electrical power and cooling for electronic hardware such as radar. Its use of engine bleed is actually less than (or comparable to) that of existing secondary systems. The turbogenerator is magnetically levitated, providing improved performance and reliability over traditional bearing technology for both the turbine and the generator. Since magnetic bearings enable the use of a high-speed, permanent-magnet generator, they also facilitate a reduction in turbogenerator size. AFRL testing demonstrated that upon starting, the ICPS operates independently of the main aircraft bus. The system isolates high-energy requirements, along with the associated detrimental impact on electric power quality, from the main aircraft electrical bus. The ICPS extracts bleed air energy to provide electrical power, as well as provide necessary cooling to the dedicated avionic device. The turbogenerator also demonstrated the capacity to reduce thermal loading. Engineers used an AFRL-developed power converter to transfer the excess electric power produced by the ICPS back to the main aircraft bus, with no detriment to power quality. Excess electric power is occasionally produced when the application requires more cooling than power. Previous systems dissipated this excess as heat. The technological capability to convert high-frequency AC or 270-volt DC power and divert it back to an electrical aircraft bus enables the ICPS to unload the main generator and, in some cases, provide the main aircraft power. This technology offers the flexibility to isolate a radar from the main aircraft bus or optimize the energy balance and integrate with the main bus.