Nothing Special   »   [go: up one dir, main page]
Scribd Logo
Upload

Welcome to Scribd!

  • 27 views

    Distributed Strain Sensing Prevents Failure in Overhead Lines and Towers

    Uploaded by

    Hugh cab
    The document discusses how distributed strain sensing can be used to monitor overhead power lines and prevent failures. It describes a field study where a distributed strain sensor system was used to continuously measure strain along a 500kV overhead power line in China over 32 km. The system detected some local strain events likely due to weather that could impact the line connections to towers. Continuous long-term monitoring of strain distribution was recommended to fully understand impacts and prevent damage.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd

    Distributed Strain Sensing Prevents Failure in Overhead Lines and Towers

    Uploaded by

    Hugh cab
    27 views3 pages
    The document discusses how distributed strain sensing can be used to monitor overhead power lines and prevent failures. It describes a field study where a distributed strain sensor system was used to continuously measure strain along a 500kV overhead power line in China over 32 km. The system detected some local strain events likely due to weather that could impact the line connections to towers. Continuous long-term monitoring of strain distribution was recommended to fully understand impacts and prevent damage.

    Original Description:

    Original Title

    500kv-opgw-china

    Copyright

    © © All Rights Reserved

    Available Formats

    PDF, TXT or read online from Scribd

    Did you find this document useful?

    Is this content inappropriate?

    The document discusses how distributed strain sensing can be used to monitor overhead power lines and prevent failures. It describes a field study where a distributed strain sensor system was used to continuously measure strain along a 500kV overhead power line in China over 32 km. The system detected some local strain events likely due to weather that could impact the line connections to towers. Continuous long-term monitoring of strain distribution was recommended to fully understand impacts and prevent damage.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    27 views3 pages

    Distributed Strain Sensing Prevents Failure in Overhead Lines and Towers

    Uploaded by

    Hugh cab
    The document discusses how distributed strain sensing can be used to monitor overhead power lines and prevent failures. It describes a field study where a distributed strain sensor system was used to continuously measure strain along a 500kV overhead power line in China over 32 km. The system detected some local strain events likely due to weather that could impact the line connections to towers. Continuous long-term monitoring of strain distribution was recommended to fully understand impacts and prevent damage.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    of 3

    Distributed Strain Sensing prevents failure in overhead lines and

    towers
    Optical ground wire (OPGW) lines are mounted on high-voltage towers. They consist of optical fibers for data
    communication and conductive wires for connecting high-voltage towers to the ground.

    Nature puts a strain on overhead lines and towers


    Being out in the open makes the lines vulnerable. Common cable failures include icing, lightning strike, tower collapse,
    and wind load.

    Theoretical models show large strain variations of the OPGW cable before icing, lightning strike or tower collapse
    occur. We wanted to validate these models.

    To understand the strain impact, we made a test set-up and measured the strain along a 500kV OPGW line
    continuously, using our distributed strain sensor system with a single-mode fiber as a sensor. The field study took
    place in Guangdong, China, with the set-up depicted in figure 1.

    Figure 1 – Overhead line test set-up

    Get precise information about changes in the strain


    We placed the distributed strain sensing controller, the NKT Photonics LIOS DSM, in a substation of the 500kV OPGW
    overhead line.

    We connected one of the controller’s optical channels to an optical single-mode fiber in the OPGW which allowed us
    to measure the strain over a length of 32 km.

    The measurement time was about 15 minutes with a minimal strain resolution (repeatability) of about 2µe. 1µe
    corresponds to a strain or compression of 0.0001% so the employed controller can detect strain changes as low as
    0.0002%.

    NKT Photonics A/S – Blokken 84, 3460 Birkerød, Denmark – Phone: +45 4348 3900 – fax: +45 4348 3901 – www.nktphotonics.com
    Figure 2 shows the differential strain between two consecutive measurements over the whole length of the OPGW
    (excluding 250 m of feed cable).

    Figure 2 – Measured strain changes in the OPGW

    Prevent damage of overhead lines and towers with strain monitoring


    Analyzing the strain profile over the 32 km shows that the overall situation is very stable. The strain change between
    the two measurements is below ±50µe.

    A few local events were detected by the DSM system, which indicates an impact on the OPGW. Those events occurred
    within 15 minutes of measuring time and are most likely due to the weather (wind), e.g. at the connection of the
    OPGW and the towers.

    Figure 3 shows the strain events in more detail.

    Figure 3 – Single strain event on the OPGW

    To analyze strain measurements, we need to know the strain change over time. Therefore, we have planned a
    measurement campaign that spans over a longer period.

    This field study shows clearly that strain measurements on overhead OPGW lines can help us understand the spatially
    distributed strain load and identify local events.

    NKT Photonics A/S – Blokken 84, 3460 Birkerød, Denmark – Phone: +45 4348 3900 – fax: +45 4348 3901 – www.nktphotonics.com
    In conclusion, strain monitoring may become a valuable feature for preventing damage of overhead lines and the
    high-voltage towers. To fully understand the strain distribution on OPGW lines requires continuous monitoring.

    NKT Photonics is the market leader in distributed optical strain and temperature sensing with more than 20 years’
    experience and thousands of systems in the field worldwide. Passive optical fibers are used as distributed sensors
    because they are immune to vibration, electromagnetic noise, dust, cryogenic temperatures, and moisture and can be
    utilized in hazardous environments. Everything made in Germany under ISO 9001 and 14001-certification.
    https://www.nktphotonics.com/lios/en/product-category/pre-vent/

    References: Stefan BREUER, NKT Photonics GmbH, Schanzenstraße 39, Building D10, 51519 Cologne, Germany, and
    Justin Junjie YU, NKT Photonics, 29/F Gopher Center, No. 757 Mengzi Road, Shanghai 200023, P.R. China

    NKT Photonics A/S – Blokken 84, 3460 Birkerød, Denmark – Phone: +45 4348 3900 – fax: +45 4348 3901 – www.nktphotonics.com

    You might also like