Airborne Lidar Technology In Power Line Asset Management
Key words: Airborne lidar, Power transmission line, Route Planning , Line Construction, Optimization route,Catenary analysis, Identification of tower construction sites, Vegetation Enchoachment management, Change detection, As built survey
Airborne lidar technology is widely accepted among power utility companies as an efficient tool for acquiring geo-referenced spatial data for various applications essential to power line asset management.
New route design can take the fundamental advantages of the lidar workflow which is all-digital format of its data collection, processing, analysis, delivery, and storage steps. By integrating high accuracy point cloud data and imageries with powerline GIS software workflow, it optimizes the route selection, tower construction site, cross section, data transfer, it realizes a seamless work flow from survey , designing, construction to transfer the asset to operation management. This maximizes the efficiency of the entire workflow, effectively avoiding duplication, saving investment. Furthermore, digital data acquired during an initial lidar survey can be archived and used to form the foundation of a permanently searchable and editable database, allowing subsequent time-based studies such as change detection.
As built powerline can use airborne LiDAR to modeling of existing routes and infrastructure, achieve a three-dimensional reconstruction of powerline corridor, recovery powerline corridor geospatial data, surface attachments (trees, buildings, etc.), the line sag, the position and the tower model, supplemented by powerline facilities and equipment parameters to achieve full digital line corridor asset management and visualization . It is often used in eengineering analysis/calculations for maintenance and upgrade, e.g. tower positions, sag analysis, thermal up-rate, load modeling, clearance and critical distances.
1. New Route Planning and Line Construction
Airborne LiDAR technology can provide users with a resolution better than 0.1 meters orthophotos, digital elevation model , cross section and contour. Surface features can be visualized, vertical and horizontal spatial information can be obtained in office computer from the chart, the designer in the office has all the feature which can viewed across computer for project design, including crops along the corridor private land boundary, houses etc.
Line Optimization and Line Construction
The site selection involves quite a lot factors, it is one of the most difficult process of transmission design. Airborne LiDAR system provides high-precision, high-resolution orthophoto (DOM), a digital elevation model (DEM) and laser point cloud data, LiDAR point cloud was loaded into professional software platform to optimize route selection and tower site selection. Through the unique spatial data processing engine, LiDAR data was compressed, stored, classified, indexed. It make the data can be fast read or searched. In the mean time, combined with two-dimensional map, a cross section view of a variety of three-dimensional map perspective, the real 3D corridor are compacted into designer’s office, which allows designers to "look around", "take into consideration of high or low stakes", consider the terrain, social factors , and ecological environment to optimize the design.
In contrast, the traditional method can not predict the cost precisely because the cost are related with the number of towers, tower type,construction site . The route and site selection are directly impact the cost of the project.
Lidar DSM colored with height
Lidar data was loaded into a powerline processing software for site selection
Tower site selection on DEM
All Digital Information Exchange
Airborne lidar technology is a powerful tool to maximize the efficiency of power line design and asset management. It represents a clear advance over traditional surveying methods for power line applications because it provides several key advantages like unprecedented data collection efficiency, an all-digital workflow and excellent data quality and accuracy. It creates a digital platform among powerline designing institutes, constructions contractor and operation companies. It realized a seamless handover the digital data on demand among the three parties. Therefore, airborne lidar data is highly suitable for reliable engineering design and analysis of the physical parameters of power lines, and for the management of powerline construction and maintenance.
The North American Electricity Reliability Corporation (NERC) issued a white paper of compliance to international standards which means powerline needs to be surveyed once per year. It has been a mandatory requirement for all North American utilities since 2014. Airborne LiDAR quickly generates accurate 3D spatial information in powerline corridor together with images for feature extraction and modeling. It can be used for :Vegetation enchoachment detection, Sag detection, thermal rating ,etc. After detection , the risk points are output with position, tower position, conductor wire information and geospatial information between risk points and powerline. This This task is providing the overhead wire maintenance team with information that could be easily read and understood on-site, and estimating the time and effort spent on the identification and analysis of potentially dangerous sites.