Overview & Events

Update EPRI Reference Books (Color Books): Reference books by the world’s leading experts were published by EPRI to assist engineers in the design of overhead lines. These books are:

• EPRI AC Transmission Line Reference Book—200 kV and Above (Red Book)
• EPRI Transmission Line Reference Book: Conductor Motion (Orange Book)
• EPRI Transmission Line Reference Book: 115–400 kV Compact Line Design (Blue Book)

These reference works are for electrical, mechanical, and compact line design analysis, respectively. As new information and research data are available, chapters of these books are updated.

In 2024, EPRI intends to provide updates for the Red Book, EPRI AC Transmission Line Reference Book—200 kV and Above, specifically Chapter 6 on lightning and grounding. EPRI is currently engaged in migration of 48 Red Book companion applications to an online platform. While this is being completed, the Red Book will ship with the stand-alone applications developed for Windows 10.

Transmission Line Workstation (Gen2) The EPRI software tool was developed to facilitate engineers in evaluating different design options effectively. Algorithms in some of the design programs may require updating based on EPRI research. Updating of this software may also be required to improve user features, add new functionalities or to be compatible with other industry software used by the design engineers. On the conductor vibration module, EPRI will endeavor to add to the vibration damper database to further increase the variety of manufacturer’s dampers, and invites members to request specific product lines not currently on the database.

Development of a Guide to Safe Design Tension for ACSS Conductor: Determining a safe conductor tension is a multi-faceted problem that requires understanding of the self-damping performance and fretting fatigue endurance of a conductor. This new initiative, which is a collaborative effort with project 35.015, is focused on helping solve this problem for ACSS conductor, as its self-damping and fatigue properties vary significantly from ACSR conductor.

Evaluation of Optimal Pole Foundation Selection: A wide range of different foundation support options exists for the support of poles. By completing the detailed design and performing a cost analysis, relatively accurate parametric studies of various foundations may be achieved. This will enable engineers to select the optimal type of foundation, based on the specific structure size, loading conditions, and geotechnical conditions. In 2023, this guide included significant re-working of installation costs following input from an experienced line contractor, and was expanded to include multiple pile foundations.

Applications of GIS-Based Line Design Tools: GIS has historically been used by utilities to track and store information related to existing transmission lines on their systems. This new initiative to launch in 2023 focuses on an alternative application of GIS, the use of GIS based tools to enhance the line design process. Initial research will focus on the validation of complete line designs using in-field GIS-based data collection forms.

Optimal Line Tension and Conductor Strength Calculator (Op10): This VBA application was developed to determine the most cost-effective installed conductor tension, based on specific project variables, and to quickly determine the impact of a selected (or existing) conductor tension. Further expansion of the capabilities of Op10 in 2024 will see the inclusion of galloping ellipses as a tension check function, and the ability to evaluate the safe tension relating to bundled conductor.

Quantifying the Real Cost of Pole Material Options: This new initiative, starts in 2024, aims to quantify the life cycle cost of wood, steel, concrete, composite and ductile iron materials when used for transmission line construction. Life cycle costing will include review of procurement, installation, and maintenance costs. The work intends to incorporate analysis of the different materials performance characteristics related to corrosion, durability, environmental-friendliness, vandalism, and resiliency.

Cost Effective Measures for the Resolution of Under-Clearance Spans: Transmission engineers commonly encounter projects where line clearances need to be raised, yet structure replacement is not a feasible option. Sources for these projects may be line up-rates, discoveries of clearance violations, rule changes, or land development induced. EPRI plans to review available methods for raising under-clearance spans without structure replacement. EPRI intends to produce a technical report on this topic based on internal expertise and input from utility members. This work will be done in coordination with EPRI’s project 35.013, Overhead Line Ratings and Increased Power Flow.

Determination of NESC C2-2023 Clearances: Navigating through multiple clauses relating to clearance calculations in the NESC requires time to ingest and understand. This training workshop, presented in two modules, aims to summarize the salient aspects of the code as they relate to clearances, to significantly the reduce amount of time needed to understand NESC requirements. The workshops, presented in collaboration with EPRI U4T, include PDH credits.

Advanced Structure Design Initiative

• Objectives and Scope

  • Develop a compact structure based on specific utility objectives:
  • Compact Low Environmental Impact
  • Optimized for structural and electrical efficiency
  • Maintainable
  • Scalable design (115-345kV)
  • Create collaborative inter-utility environment to determine and evaluate best design concept
  • Perform mechanical and electrical testing and validation where appropriate

• Value

  • Utilize concepts and tools from Advanced Overhead Line Design Supplemental project
  • Assess potential benefits of new technologies, materials and solutions * Incorporate the most valuable technologies

Advanced Overhead Line Design

• Objectives and Scope

  • Develop an approach on how utilities can use advanced technologies, solutions, and tools to extract the maximum value and performance of new lines, focusing on:
  • Increased electrical and mechanical reliability
  • Reduced cost of installation and operation
  • Improved maintainability and safety
  • Reduced environmental impact
  • Increased transfer capacity
  • For each of these focus areas, the approach will aim to advise how different new technologies and state-of-the-art design practices can be brought together to achieve these goals.
    
    

• Value

  • Develop a state-of-the-art approach to overhead line design.
  • Incorporate the most valuable technologies and solutions into overhead lines of tomorrow.
  • Extract the maximum performance from new line designs while ensuring reliability and maintainability.
  • Aid, utilize, and account for key emergent issues in new line designs.

Mitigating Vortex Induced Vibration (VIV) on Steel Pole Davit

• Objectives and Scope

  • Develop a computational model to determine the extent to which resonant frequencies of davit arms intersect with vortex shedding frequencies, and the fatigue stresses that may result.
  • Produce a computational tool to assess the risk of VIV damage
  • Investigate the efficacy of different countermeasures and design methods that may mitigate VIV
  • Verify the adequacy of the computational model in wind tunnel testing (Phase 2)
    
    

• Value

  • Understand when vortex induced vibration may become a risk
  • Effectively mitigate against resonant vibration * Develop and use a predictive tool to assess vortex induced vibration

Design and Installation of Vibrated Steel Caissons – SPN 3002022285

• Objectives and Scope

  • Participate in full-scale testing of Vibrated Caissons
  • Evaluate the impact of overturning and compression loads on steel caissons
  • Gain access to software developed specifically for the analysis of steel caissons for overhead lines
    
    

• Value

  • Enable greater accuracy and optimization for vibratory pile capacity analysis
  • Evaluate the analytical models developed in Phase 1 using full scale testing
  • Assess both compression and overturning capacity of vibrated caissons in full scale tests
  • Develop software based on analytical models, adjusted based on the results of testing * See SPN 3002016622 for Phase 1 deliverables and pricing

Understanding Load Capabilities of Polymer Braced Post Insulators – SPN 3002008679

• Objectives and Scope

  • Develop FEM models to predict strength of various braced post systems
  • Verify models from full scale load testing
  • Develop a software tool to predict the generic capacity of braced post systems
    
    

• Value

  • Predict the strength of generic post and braced post insulators, across a range of suppliers
  • Specify a testing procedure to verify the capacity of braced post insulators
  • Correct modeling of post and braced post insulation systems
  • Integration with PLS Pole/ Tower and PLS CADD