N14A-T025 TITLE: Improving the Life Expectancy of High Voltage Components Using Nanocomposite Surface Solutions

TECHNOLOGY AREAS: Materials/Processes

ACQUISITION PROGRAM: Fixed Submarine Broadcast System

OBJECTIVE: Develop surface coatings to improve the high voltage, wet-limit performance and longevity of dielectric and conducting materials used in VLF/LF (Very Low and Low Frequency) antenna components for the Fixed Submarine Broadcast System (FSBS).

DESCRIPTION: Transmission power ranges for VLF/LF (Very Low and Low Frequency) antennas used in the FSBS radiate from hundreds of kilowatts to megawatts. The high voltage operation at these sites and their exposure to the elements (e.g., rain) can quickly age and cause failure in the materials used in the VLF antenna components. The three major components that are affected by external environmental conditions are the insulating materials of the feed-through bushings, the dielectric supports for the tuning coils and the structural members of the insulators. Failure modes for the materials vary, but generally result in burning or fire due to high voltage arcing and surface tracking. Improved surface coatings will prevent the premature failure of these materials preventing downtime and costly replacement of damaged parts. The long term goal is to have the components perform in all weather conditions as well as they perform in dry weather.

The Navy is interested in proposals for new surface coating treatments that actively prevent surface damage to materials used in the VLF system for all weather conditions and during high voltage operation. The surface coatings should take into account the following requirements: 1) Compatible with existing VLF device materials, 2) Ease of application, 3) Sufficiently water repellant, 4) Highly-insulating and non-conductive so as to prevent arcing, 5) Relative small feature sizes to avoid "hot spotting," 6) Uniform coating quality, and 7) Long lasting requiring infrequent applications. Solutions of particular interest are superhydrophobic surfaces and other nanocomposite surfaces that can actively control water droplets. Development of such innovative surface treatments should demonstrate coatings that scale up to component size, resulting in significant reduction in failures and overall cost effectiveness.

PHASE I: Explore and define protective surface coating technologies that prevent the ingress of water into the internal layers of the materials. Demonstrate feasibility of the coating treatment for improved environmental conditioning. Demonstrate feasibility of the approach through limited testing on small sample pieces. Analyze the expected costs (non-recurring and recurring) and performance on a full size component and provide a plan for proof of performance.

PHASE II: Fully develop the concept demonstrated during Phase I through a process specification and demonstration of industrial reproducibility. Deliver to the government surface coating treatments. Demonstrate the scale up to component size and test coatings. Present an approach for manufacturing the surface coating.

PHASE III: The final protective coating technologies shall be developed with performance specifications satisfying targeted acquisition program requirements coordinated with technical point of contact. Perform verification and validation of the developed process. Demonstrate system reliability, maintainability, and environmental ruggedness in the overall system design.

PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: All weather surface solutions/treatments compatible with high voltage/high electric field equipment has immediate application in the commercial power industry.

REFERENCES:
1. VLF Radio Engineering; by Arthur D. Watt; Pergamon Press, 1967.

2. VLF/LF High-Voltage Design and Testing, SSC San Diego TECHNICAL REPORT 1904; by Hansen, Peder & A. D. Watt, September 2003.

3. "Superomniphobic Surfaces for Effective Chemical Shielding" S.Pan et al. J. Am. Chem. Soc., 2013, 135 (2), pp 578�581. DOI: 10.1021/ja310517s.