Objective:
Overhead transmission (OHT) systems present unique asset management challenges due to their significant capital costs, large and geographically dispersed footprint, public-facing profile, and vital function of moving bulk power within and among utilities. This project intends to address these challenges by increasing transmission system business intelligence capacity, developing decision support tools and methods for overhead transmission systems and individual components, and applying new insights and inferences extracted from analysis of asset data, e.g., inspection, condition assessment and maintenance history. The project aims to:
- Receive utility data; organize and curate received data; design, develop and update data models.
- Develop and populate databases using developed data models and the extracted information from utility-supplied datasets.
- Analyze database content; assess and understand factors and variables influencing asset performance.
- Develop metrics to quantify existing performance.
- Develop methodologies to assess performance and risk.
These elements are meant to be integrated into a comprehensive decision support framework. Research results provide utilities with new knowledge and information vital for effective asset maintenance and management, inlcuding:
Research Value:
- Analysis-based risk-informed decision making supported by sound technical basis.
- Improved capital planning, inspection, and maintenance prioritization.
- More efficient use of maintenance resources to manage operational risk.
- Early identification of component type issues, reducing unplanned outages.
- Reduced unplanned expenses and increased benefits and value of planned work.
- More effective use of existing infrastructure and data.
- Improved data quality and value from using consistent data formats suitable and useful for overhead transmission asset analytics.
Public benefits from this R&D may include improved quality of service from a reduction in unplanned outages and costs, better utilization of capital, and improved customer satisfaction and service availability.
Planned 2025 Research
Analytics for Fleet Management of Transmission Line Wood Poles and Metal Structures plans to investigate and develop population performance metrics based on condition assessment data for transmission line structures. The analytics are developed using results from utility-supplied inspection, replacement and demographic data, subject matter expert experience, and other inputs such as operating environment. The analytics may lead to the development of statistical models of structure performance. The models could be applied to plan capital and maintenance investments, prioritize inspections, and develop risk mitigation strategies (e.g., wildfires, extreme weather events, etc.).
Planned efforts in 2025 include:
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Wood Poles:
- Continue collection and processing of industry-wide wood pole inspection, replacement, and demographic data.
- Continue development of analytic techniques to better understand the useful life of wood poles and the effect of variables such as service age, species, original treatment type, environment, inspection providers, pole dimensions, etc.
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Metal Structures:
- Continue collection and processing of industry-wide steel structure inspection, replacement and demographic data.
- Continue development of analytic techniques to better understand the performance of steel structures and the effect of variables such as service age, land cover type, soil chemistry, environment, etc.
Analytics for Fleet Management of Transmission Line Conductors and Shield Wires proposes the investigation and development of condition assessment analytics for transmission line conductors and shield wires. The analytics are developed using laboratory testing of utility supplied field-aged samples or live line assessment results, replacement and demographic data, subject matter expert experience, and other inputs, such as operating environment. The analytics could lead to the development of statistical models of conductor and shield wire performance. With sufficient data, the models can be applied to investigate population survival rates and plan capital and maintenance investments. EPRI can work with members through a one-on-one supplemental project to help collect field-aged samples and perform tests to initiate the collection of the data necessary for analytical model development. Efforts in 2025 intend to:
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Continue collection of industry-wide field-aged conductor and shield wire samples and data, from laboratory condition assessments, replacement records, and demographic records.
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Continue development of analytic techniques to better model the degradation of conductors and shield wires and the effects of variables such as environment.
Analytics for Fleet Management of Other Transmission Line Components aspires to investigate the development of population performance metrics for other transmission line components such as insulators and arresters. Key research questions and readily available data (inspection, failures, replacement, maintenance, test results, subject matter expert experience, operating environment and other relevant EPRI research) will be identified with guidance from participating members to enable the development of suitable analytics. The development may lead to new knowledge for use in planning maintenance and capital investments, inspections, and replacement decisions.
Overhead Transmission Line Risk Assessment for Fleet Management intends to investigate and develop risk assessment analytics for OHT systems, considering both individual components (such as conductors, structures, insulators, and arresters) and lines as an integrated system of components. A practical and holistic approach to transmission line risk assessment will be investigated using industry-wide data such as condition assessment results, maintenance records, asset demographic information, degradation research and subject matter expert experience. Efforts in 2025 intend to:
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Continue developing and testing data models to collect inspection and maintenance records and associate them with the underlying component and circuit.
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Populate the data models with utility supplied data to assess applicability; make changes based on experience.
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Continue developing new circuit and component level metrics to better understand circuit and component performance.
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Research other available data sources such as geospatial information and evaluate their usefulness.
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Develop and deliver a prototype software framework that utilizes results of the above-mentioned tasks to help utilities gain a systemic view of transmission line risk.
Applying Geospatial Data for Overhead Transmission Asset Management plans to survey the publicly available and readily accessible geospatial data sources (e.g., wildfire, vegetation, climate, corrosion) and investigate and document the applicability and usefulness of these resources for augmenting utility supplied data. This will allow for deeper and more informative insights regarding risk factors associated with asset location. Efforts in 2025 intend to continue the investigation and documentation and publish a technical brief on this topic highlighting potential applications of value, best practices, as well as capabilities and limitations of these resources.
Applying Advanced Data Science and Statistics to Improve Overhead Transmission Asset Analytics intends to explore the applications of advanced data science and statistics to the extraction of information from disparate sources to better understand OHT asset condition and performance by:
- Assessing the state of the image analysis science regarding the availability and applicability of image-based data sources that can be utilized to support approaches to supplement existing analytical approaches utilizing more traditional data sources (e.g., spreadsheets containing inspection records, maintenance records, demographic information). This work focuses on available data resources identification, data characterization, computation infrastructure requirements, and industry leading practices.
- Evaluating the applications of advanced data science and statistical techniques to analyze inspection and maintenance records with the goal of developing new metrics to better understand transmission line and component performance.
In 2025, researchers intend to publish a technical brief highlighting use-cases.
Data Specification for Overhead Transmission System Component Performance Analysis intends to provide a catalog of OHT system component characterization data, including demographic and condition assessments, which are useful as inputs to EPRI analytics, and the formats required by those analytics. The work in this task is based on EPRI investigations of utility supplied data. In 2025, EPRI intends to review and update data models and definitions for select assets such as wood poles, metal structures, conductors, and shield wires.
Anticipated Deliverables
Deliverable | Date |
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Circuit Breaker Asset Management Analytics: Data Requirements, Family Groupings and Maintenance Taxonomy (Technical Update) | December 2025 |
Actionable Insights Based on Analysis of Industrywide Circuit Breaker Data & Their Application in Procurement, Maintenance and Replacement Decisions (Technical Brief, Webcast and Results on TRC) | December 2025 |
Computer Assisted Analytics to Categorize Circuit Breaker Maintenance Work Orders (Analytical Tool & Application Guide) | December 2025 |
Circuit Breaker Risk Ranking Framework (Software & Application Guide) | December 2025 |
Using Relay Event Data to Better Understand Breaker Operating Performance and Patterns (Technical Update & Webcast) | December 2025 |
Actionable Insights Based on Analysis of Industrywide Power Transformer Data & Their Application in Procurement, Maintenance and Replacement Decisions (Technical Brief, Webcast and Results on TRC) | December 2025 |
Power Transformer Expert System Software (Software & Application Guide) | December 2025 |
Advanced Analytics for Power Transformer Condition Assessment (Technical Brief & Webcast) | December 2025 |
Actionable Insights Based on Analysis of Industrywide Substation Battery Data & Their Application in Maintenance and Replacement Decisions (Technical Brief, Webcast and Results on TRC) | December 2025 |
Evaluating the Efficacy of Substation Battery Monitoring to Help Utilities Reduce Response Time & Drive Condition Based Maintenance (Technical Brief & Webcast) | December 2025 |
Asset Performance Metrics for Disconnect Switches and Capacitor Banks (Technical Update) | December 2025 |
Protection and Control System Asset Management Metrics (Technical Update) | December 2025 |
Development & Application of Analytical Approaches to Aid Allocation of Resources Across Substation Assets (Technical Update & Utility Information Exchange) | December 2025 |
Developing an Analytical Framework to Capture Expert Knowledge that Can Aid Field Personnel in Maintenance and Troubleshooting (Technical Update & Webcasts) | December 2025 |
Application of Natural Language Processing to Improve Substations Asset Management and Maintenance (Technical Update & Webcasts) | December 2025 |
Past EPRI Work on Topic
Product ID | Title | Description | Published Date |
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3002026884 | Overhead Transmission and Distribution Wood Pole Fleet Management | This report documents the development of methodologies for the analysis of historical inspection, maintenance and demographic data, and application of analysis results to inform transmission wood pole fleet inspections and capital planning and application to line risk assessments. | December 2023 |
3002026887 | Overhead Transmission Steel Structure Fleet Management Analytics – Analysis of Lattice Tower Inspection Data | This report documents the results of EPRI’s investigation of one utility’s lattice structure demographic and condition assessment data to better understand the aging and deterioration rates of their lattice structures, with a focus on determining how best to analyze such data and what insights could be obtained to support asset management decisions regarding maintenance and replacement. | December 2023 |
3002026886 | Overhead Transmission Conductor and Shield Wire End of Life Model Development | This report documents the development of methodologies for the analysis of utility-supplied laboratory testing of field aged samples or live line assessment results and application of analysis results to inform transmission conductor and shield wire inspections and capital planning and application to line risk assessments. | December 2023 |
3002026888 | Overhead Transmission Line Risk Ranking Assessment Framework – Development and Demonstration | This report documents methodologies and a framework for constructing an index that could be used to support maintenance and replacement decisions for individual line components, groups of components, or a complete line. | December 2023 |