Overview & Events

Research Value

• Provide technical information for developing more effective specifications and improving the long-term performance of composite components.
• Reduce construction costs and improve performance through correct handling and applying of composite components.

Member Benefits

• Extending polymer insulator life can reduce the occurrence of sustained outages, which helps maintain a reliable electricity supply to the public.
• Improve technical knowledge and productivity by providing better information and tools.

At A Glance

Polymer insulators offer a lightweight and improved contamination performance alternative to porcelain and glass insulators. Although many of the early design challenges have been addressed by manufacturers, utilities still need to understand how to select, apply, and inspect these components to achieve the expected design life.

Understanding their long-term performance and developing short-term tests can help utilities gain knowledge to confidently specify and apply polymer insulators. This can help minimize the mechanical and electrical stress on the insulators in their designs while selecting components capable of meeting the long-term performance requirements.

This project addresses the specification, application, inspection and in-service performance of polymer insulators through long-term and short-term research tasks, such as:

• Testing in full-scale and small-scale aging chambers to help identify aging and degradation mechanisms.
• Software tools for determining electrical stress levels.
• Development of short-term tests to assess insulator performance, particularly for new designs or manufacturers on the market.
• Workshops where utilities can stay up to date on insulator developments and test methods.

Key Activities for 2023

• Multi-Stress Aging Tests: For more than two decades, EPRI’s multi-stress aging chamber has provided utilities with timely information about the performance of polymer insulators in one-tenth the time it would have taken from in-service experience alone. As such, the chamber continues to be an asset to utility members and the selection of components are adjusted based on the needs of the industry.
• Small-Scale Degradation Tests: EPRI’s small scale degradation tests have been proven repeatable, reproducible, and relevant to assessing an insulators corona resistance. As new materials are developed, these tests are performed to provide members with performance guidance.
• E-Field Modeling Software: As Electric fields are a critical factor in the service life of polymer insulators, this software helps to calculate the electric field on new or existing insulator designs so that utilities can determine the need for corona rings.
• Polymer Insulator Population Assessment (PIPA): This population assessment software determines the potential condition and failure risk of in-service populations of insulators. Members can use this tool to quickly understand which population of insulators is prone to degradation. In 2023, further adaptation to an online version is planned.
• Insulator Reference Book: This book is a comprehensive reference guide that provides state-of-the-art information on insulator selection, inspection, and maintenance. In 2023, EPRI intends to expand on the chapter on mechanical application on insulators.
• ADSS Application: A software tool to help users understand the electric field influence of high-voltage transmission lines on all-dielectric self-supporting (ADSS) installations. In 2023, further adaptation from a desktop version to an online version in planned.
• Handling Tests: These tests are being developed as a supplement to performance tests. They are intended to identify polymer insulators that, in addition to meeting in-service performance needs, resist handling damage. In 2023, EPRI anticipates development of test criteria of handling resistance tests.
• Non-destructive Weathershed Bonding Assessment: This task is evaluating a combination of ultrasound technology and non-destructive stress application to reveal poor weathershed bonding in polymer insulators. In 2023, EPRI intends to design a bonding stress tool based on previous trials.

Engagement Opportunities