Research Status & Deliverables

Performance of polymer bushings under extreme environmental conditions

• The three ABB RIS bushings installed in the 138 kV Research Substation have been energized for over 5 years and subjected various harsh environmental and loading conditions following a well-defined test plan. There is still no evidence of deterioration of the bushings based on the off-line testing or the bushing monitoring system.

• The next offline testing of hydrophobicity, power factor and dielectric frequency is scheduled for 2Q 2024.

• Given the long-term nature of the testing in the 138kV Research Substation, a number of efforts aimed to generate near term insight and information are contemplated. These include data collection efforts, to leverage the collective experience of all project funders, as well as more targeted experimental efforts to understand specific aspects of polymer bushing performance, such as sensitivity to overload.

• A new aging chamber for accelerated bushing testing has been constructed. This chamber will give the ability to test 34.5 kV and 69 kV bushing in various voltage, current and ambient/ humidity conditions.

Guidelines on specification and maintenance of polymer bushings

• This document presently contains the best information available to the industry at this time. The 2023 revision of this document included some material on the load capability of polymer bushings for the first time. Contemplated research for 2024 may add some experimental insights to this important topic.