SBIR-STTR Award

Sulfur Hexafluoride (SF6) is a gaseous dielectric used for suppression of high-voltage breakdown by the electric power industry and airborne military radar systems, including the Airborne Warning And Control System (AWACS). SF6 is chemically inert and a very efficient infrared (IR) absorber, which make it a very potent greenhouse gas (GHG) whose impact on global warming is estimated to be 24,000 times greater than CO2. Prior studies have not found a "universal" non-GHG replacement gas, consequently eliminating or reducing the use of SF6 needs to be investigated on a case-by-case basis for each application. This program will develop a step-by-step procedure that evaluates each component of a military radar system, calculating the voltage stress levels, determining the SF6 effectiveness, and investigating whether cost-effective modifications can be made to reduce or eliminate the use of SF6. Although the methodolgy will be general, the specific candidate system to be investigated will be the high power microwave portions of the AWACS radar. Because the AWACS radar system was designed long before the GHG properties of SF6 were recognized, it is likely that progress can be made in reducing or eliminating the use of SF6.

Keywords:
Sf6 Replacement, Voltage Breakdown, Awacs, Greenhouse Gas, Dielectric

The development of capabilities that allow significant removal or reduction of high Global Warming Potential (GWP) Green House Gases (GHG) in the environment is paramount to ensure human health and welfare. The objective of this effort is to develop critical components and technologies that will significantly reduce the need for GHG on the Airborne Warning and Control System (AWACS). In Phase I, Microwave Applications Group (MAG) determined that stress levels in two critical AWACS components – as currently configured – require the use of Sulphur Hexafluoride (SF6) – known to be a GHG. Therefore, the focus of Phase II is to develop replacement configurations of these components such that the use of SF6 is not required. That hardware will then be tested to ensure compliance with AWACS requirements.

Benefit:
Concepts leading to hardware configurations – which are proven in this effort to operate successfully without a GHG – will lead to development of replacement components in military and commercial applications. These applications include radar systems, linear accelerators, and other electrical and radio frequency system requirements.

Keywords:
Global Warming Potential (Gwp), Green House Gases (Ghg), Sulphur Hexafluoride (Sf6), Fc-77, Phase Shifter, Rotary Joint, Switchgear, High Power