The Electric Power Research Institute (EPRI) initiated a concerted effort into the application of unmanned aerial systems (UASs) for transmission research in 2012. The effort has accelerated and grown as UASs have increased in their capability and the Federal Aviation Administration (FAA) regulations have relaxed.
The first challenge was defining the role EPRI should play to meet the mission of supporting utilities to provide safe, reliable, cost-effective and environmentally responsible electricity for the public benefit. The team developed a comprehensive research plan to provide EPRI members with the technical basis and business case to effectively and safely take advantage of this ever-changing technology.
Presently, 23 utilities are fully engaged in the EPRI transmission research project. The most active members in the research project are leaders in the field, implementing regular UAS missions and pushing the envelope by doing trials of new technologies such as beyond-line-of-sight inspections.
EPRI is developing use cases that define potential applications for UASs to aid in all aspects of the transmission asset life cycle, with transmission line inspection being a first priority. Other applications such as complementing transformer inspections, aiding in conductor stringing and performing micro-ohm meter measurements on conductor splices will aid utilities with applying UASs in the field, and aid technology developers and service providers to adjust their offerings to meet the industry’s needs.
Evaluation and Demonstration
To date, EPRI has executed two fly-offs to evaluate the capability of different technologies and service providers in a well-defined scientific manner. In 2014, an evaluation of six different technologies was implemented in Canada on de-energized structures at HydroOne. In 2015, six different service providers were evaluated in New York in an EPRI-funded, -designed and -led test at the New York Power Authority on 345-kV structures. This evaluation was attended by all of the funding utilities with more than 40 EPRI advisors present.
In both tests, vendors and providers were given well-defined requirements and had to submit results in a consistent format. The flights and inspection procedures were observed, and the submitted inspection results were measured to evaluate effectiveness. The evaluations provided immediate results that can aid industry in the selection of technology as well as practices of excellence in inspection and reporting.
The results of these evaluations have been provided to members in both video and report formats. A publicly available summary has been posted by EPRI on YouTube as “UAS Field Test Summary.”
Operations in an Electrical Environment
It is important to confirm that UASs perform in an effective and safe manner without impacting the reliability of transmission system. Testing is required to confirm UASs can exist in complex electrical environments; including those in which magnetic fields, corona and arching activity exist. EPRI is developing and executing a test protocol that can be used to confirm that any technology to be used on transmission assets can withstand this electrical environment. A possible use of this test protocol would be to ensure technology and service providers are able to safely and effectively operate in a complex electrical environment.
Testing also is being performed to determine the impact of UASs on the flashover strength of the air gaps and insulator strings to ensure reliable and safe operation of the transmission system.
Finally, the team is documenting safe work practices for operators and the public.
One of the major deliverables that will be provided as a result of this work is a functional specification utilities can use to acquire UASs or engage service providers. Functional specifications will address topics ranging from how to operate in windy conditions, how to operate in high electric and magnetic fields, and how results should be collected and presented.
Business Case and Awareness
In September 2015, EPRI published the “Update on FAA Regulations on Unmanned Aircraft Systems: An EPRI White Paper” to document the state of FAA regulations in the United States. This document aids EPRI members in navigating the current state of UAS regulations. EPRI is also developing a framework to help utilities build business cases to confirm the need for the use of UASs.
As UASs are increasingly embraced by transmission utilities, the research needs will change. Together with its membership, EPRI will adjust and adapt the research portfolio to meet these new challenges and close the gap between utility and regulatory requirements and evolving technologies.
Andrew Phillips is director of transmission for the Electric Power Research Institute.