Research Status & Deliverables

Task: Guidelines for Thermo-Mechanical Design of Extruded Dielectric Cable Systems
Task Description: This multi-year task builds on and continues EPRI’s prior research in laboratory verification of thermo-mechanical behavior of extruded dielectric cables in ducts, pipes, and manholes. The report will include development of a validated source of practical engineering knowledge to assist cable engineers in designing extruded dielectric cable systems with respect to their thermo-mechanical effects. The report covers cable mechanical parameter measurements, finite element analysis modeling, engineering software tools, full-scale laboratory validation, applications at utility sites, and subject matter training.
Update:

• The team is preparing connectors for the third cable mechanical parameter testing.

Task: Advanced Sensors and Inspection Techniques for Extruded Dielectric Transmission Cable Systems
Task Description: This multi-year task is a continuation of the study on advanced sensors and monitoring techniques for inspection of cable system condition and operational status. The task covers developments of test rigs and performs tests to evaluate the effectiveness of available technologies and to demonstrate emerging technologies. Field trials on host utility cable circuits may be included to demonstrate technologies and collect measurement data from the fields.
Update:

• The project team is preparing to install various sensors on the 138-kV test rig in the EPRI Lenox Laboratory.

Task: Aging Characteristics of Extruded Dielectric Cable Systems and Components
Task Description: Many extruded dielectric cable circuits are approaching 30-40 years in service. There is a need to develop an approach to study their management and life expectancy. This task is a series of laboratory experiments to better understand extruded dielectric cable system aging and failure mechanisms. This task is now expanded into three different tests:

• Mechanical bending aging tests (30,000 to 60,000 cycles)
• Full-scale thermo-mechanical aging tests (65, 80, 90 and 105 ºC)
• Outdoor accelerated aging tests (138-kV and load currents)
  The aging tests are to include both land and submarine cables, and accessories of different designs at different transmission voltage levels

The aging tests are to include both land and submarine cables, and accessories of different designs at different transmission voltage levels.
Update:

• Various mechanical bending aging tests have been completed. Full-scale thermo-mechanical tests are in progress. Outdoor aging tests are also in progress.

Task: Asset Vintage Guide for Extruded Dielectric Cables, Terminations, and Joints
Task Description: How an asset degrades and fails is often dependent on how the asset was designed and manufactured. This task develops and updates vintage information for component materials, design, manufacturing, and other known issues of extruded dielectric cable systems.
Update:

• Additional information will be added to the document.

Task: Quality Guidelines for Grouting Procedures for Large Casings Used for Transmission Cable Systems
Task Description: This report is an update of a prior EPRI research to document and evaluate utility experiences with grouting, describe steps required to properly design and install high-quality grouts, evaluate grout mixtures and installation procedures, describe quality control procedures, provide a summary of lessons learned, and provide a typical specification that utilities can use as a guide.
Update:

• The report is under review.

Task: Underground Transmission Vault Corrosion: Inspection Assessment and Remediation
Task Description: This task addresses common corrosion issues within underground extruded dielectric cable joint vaults. The report discusses corrosion mechanisms within the vaults and provides inspection and assessment results on components within the vaults. It also provides remediation recommendations based on results of field inspections and laboratory testing. Update:

• The task is under review.

Task: Technology Review of Extruded Dielectric EHV Cable Systems, 220 to 500 kV
Task Description: This task is to build on prior EPRI studies on the same topic and provide a state-of-art technology review to assist utility cable users in making engineering decisions for reliable and cost-effective in-service operations. The report captures evolving technologies, success and failure experience, and lessons learned to enforce the needs for continuous vigilance during design, manufacturing and installation processes of both cables and accessories.
Update:

• The task is under review.

Planned Deliverables for 2024

2023 Deliverables

Key Deliverables