Research & Technical Content

1: Research Result Summaries

1.1: SF6 Leak detection

1.2: SF6 Alternatives

1.3: Guidebook Development

2: Reference Information

3: Videos

Research Result Summaries

1 - Research Result Summaries

1.1 - SF6 Leak detection

SF6 leak detection is important due to the increasing pressure to reduce SF6 emissions. EPRI has completed extensive testing with cameras at ground level (see EPRI report 3002024618 chapters 6 and 7). From that research there were many learnings. One of those learnings is highlighted below. It demonstrates the large role the background plays in SF6 leak detection using infrared-based technologies. A sky background significantly increases the sensitivity of the detection. With that sky background removed, it can be seen in the image below that the exact same leak is made indetectable.

Looking forward, the current research is building on that past research to address the important question on how to detect SF6 leaks at high elevations without the need for an outage or ladders or scaffolding. To achieve this, research is exploring how effectively SF6 leak detection can be performed from a UAV. In August this year tests will be conducted in the energized EPRI research substation using controlled SF6 leaks. An example of a controlled leak is shown below.

This controlled leak will be placed in the substation in the location shown below. The research will be examining the ability of the UAV-mounted camera to detect leaks at various distances – and whether there is strong influence from the wind produced by the UAV rotors and whether the UAV platform is stable enough to perform the necessary frame subtractions.

1.2 - SF6 Alternatives

To answer the wide range of questions related to new alternatives to SF6 (vacuum and Fluoronitrile solutions) research is underway in two EPRI laboratories. The first laboratory in Charlotte, NC is researching the following aspects related to Fluoronitrile SF6 Alternatives:

Handling
Analysis
Recycling
Disposal A close-up view of the Charlotte, NC laboratory is shown below.

The second laboratory is in Lenox, MA and is being modified to allow for the deployment and evaluation of new SF6-free breaker technologies. The research will allow for a deeper understanding of the breaker performance before deployment in a substation serving customer load. Utilities are accelerating the progress the supplemental funding to support the deployment of breakers.

1.3 - Guidebook Development

GIS Map of the on-line GIS Monitors under evaluation

Hover over these links to locate a monitor or view more information on research:

The current guidebook version is the EPRI product ID 3002024618. It covers the important topics of condition monitoring and SF6 leak detection. In 2023 it is being expanded to include the new research this year on expanding the EPRI RF Monitoring Suite to include GIS and GIL monitoring. Monitoring is focused on three areas:

AE (Acoustic Emission) monitoring for partial discharge detection
SF6 Density monitoring for early detection of leaks
Tank temperature monitoring for early detection of internal overheating An example of an AE (Acoustic Emission) monitor on the GIS in the EPRI laboratory is shown below. In 2023 the sensitivity and internal signal processing of this approach continues to be improved.

In parallel research is underway on using EPRI RF Monitors to detect PD in GIS and GIL via high frequency currents in the ground straps. Below is an image of some recent tests that have demonstrated early success with the approach – as seen in the response from the monitor seen below when excited by a standards-based PD generator. In the months ahead the detection will be optimized and then proven with field trials.

2 - Reference Information

Key information from reference documents and guides (e.g.) or succinct descriptions of concepts (e.g. what is risk and how do I visualize it)

3 - Videos

Updates on tasks or tests