W.I.R.E. Services, a division of Manitoba Hydro International Ltd. (MHI), recently completed an aerial LiDAR survey and engineering upgrade project for a large transmission line utility in Panama. The project included a LiDAR survey from which W.I.R.E. Services created 3-D dynamic models of the utility’s transmission lines and went on to analyze the lines for upgrade opportunities. W.I.R.E. Services specializes in using LiDAR data for transmission line applications and routinely integrates highly accurate LiDAR survey data for utilities. By using state-of-the-art transmission line modeling software like Power Line Systems’ PLS-CADD, PLS-POLE and PLS-TOWER, models can be created and analyzed for any operating scenario required by the utility.
The project evaluated the current condition of 10-230kV transmission lines located throughout Panama using LiDAR technology as well as high-resolution imagery and video. Ground-based weather stations were set up along the transmission line route during the survey, and electrical loading was monitored as well. Using IEEE Standard 738-06, the exact conductor temperature at the time of survey was calculated and used in PLS-CADD to create an accurate “as-built” model of the existing transmission lines. With the as-built model complete with structural tower models, W.I.R.E. Services could simulate extreme operating conditions to ensure adequate clearance was maintained and structures weren’t overloaded.
The project delivered 868 kilometers of LiDAR survey data, PLS-CADD models, thermal rating analysis, vegetation studies, PLS-TOWER models with complete structural analysis and a comprehensive upgrade solution package. The transmission lines were designed for a 220MW rating, and the target upgrade rating was 350MW. W.I.R.E. Services’ analysis determined that all the transmission lines in their existing condition couldn’t operate at 220MW. To upgrade the lines, modifications were engineered to fix the existing problems and increase the capacity to 350MW. A core component of the upgrade solution package was to identify and analyze tower structure inadequacies. The as-built model showed the conductors were already at the maximum allowable tension, so suggested upgrades included adding midspan structures, replacing existing structures and adding extensions to existing towers. As a result, the utility required other modifications, such as shield-wire and conductor shifts, as well as conductor removal.
One of the advantages of using LiDAR data for the survey was the high level of detail in the point cloud. Structure types were identified from the original plan and profile data. The LiDAR data revealed that the tower types identified on paper weren’t the same as in the field. The pictures at left show one example of the discrepancies found.
The analysis and upgrades that W.I.R.E. Services provided will enable the utility to transmit more power and provide increased reliability to its customers. Manitoba Hydro has been an industry leader in developing methods to integrate better survey data with software to accurately produce transmission line models so utilities can operate safely and efficiently. The upgrade solutions and analysis that W.I.R.E. Services provided the Panamanian utility have been gleaned from the Manitoba Hydro Transmission Line Department’s engineering experience. W.I.R.E. Services is able to provide solutions to achieve desired new ratings while minimizing costs and transmission line outage times. The final upgrade solution package in Panama was a comprehensive list of line and tower modifications required to achieve the new rating and recommended safe work procedures.
For more information, visit W.I.R.E. Services at www.wireservices.ca.