P37.101: Transformer Life Management

Transformer of the future: As utilities respond to rapid load growth, there is the parallel challenge of how to leverage new and emerging transformer technologies. EPRI’s expertise and third-party independence provide a valuable path for rapid learning. The collaborative nature of EPRI research provides this learning at a much lower cost than any one utility evaluating the technologies on their own. The learnings help reduce the risks for the industry associated with selection and deployment of these new technologies. Examples include resilient transformer concepts, flexible transformers (voltage, impedance, etc.), transformers with novel fluids, solid-state transformers, and transformers pre-hardened for stresses such as Geomagnetically Induced Currents and ballistic impact.

EPRI Power Transformer Guidebook (Copper Book) 2027 update: In 2027, research will allow for expansion of the guidebook on the ever-increasingly important task of procedure development for factory visits and inspections once a transformer arrives on-site. This valuable guidebook is updated every year to keep members up to date with the latest research, technology developments, and transformer standards. Written for utility engineers and field staff, it covers topics all the way from specification to end-of-life assessment.

Life Extension of existing transformers: Keeping a transformer dry over its life can significantly extend its life. EPRI R&D has developed a technique to keep a transformer dry, but without the need for constant cartridge replacements. This allows for life extension at lower O&M costs.

Technical webinars on the Transformer Guidebook: Each year, multiple technical webinars are hosted based on chapters from the Transformer Guidebook. The webinar materials are published afterward to allow convenient, ongoing access. Topics are selected to accelerate learning on the most important subjects, identified with input from the project members.

Evaluating online monitoring technologies to guide specifications: In 2027, EPRI will execute newly developed test plans on a wide range of on-line monitors (DGA, bushing, Partial Discharge). The new test protocols are designed to be faster but still highly insightful. The results provide valuable assistance in transformer monitor specification, interpretation, and adoption. The unique EPRI approach allows for rapid answers on high-impact decisions that are then applied fleet-wide in a utility.

Guiding the application of novel fluids for transformers: The 2027, research helps the industry in selecting fluids, understanding performance over time, and solving practical problems such as leak sealing and fluid mixing (intentional or unintentional). Over time, the chemical and physical properties of novel fluids can shift significantly from their original values. In many cases, these properties may exceed the limit values that were originally established for mineral-based insulating oils. Despite these changes, novel fluids such as ester fluids are often kept in service, and users may not fully understand how degraded fluid properties can negatively affect transformer performance and long-term health. Accelerated aging studies can provide valuable insight into how changes in key chemical and physical properties—such as acid number, fire point, and viscosity—impact system operation and condition. This research helps define appropriate operating limits for ester fluids and supports informed decisions on maintenance actions, fluid replacement, and potential adjustments to transformer loading.

Expanding the insights from oil analysis: There are untapped insights in the oil samples already being collected and analyzed. 2027 EPRI, research helps reveal these insights and aids the industry in reducing the risk of transformer failures and in enhancing estimations of remaining life. Data collected from a unique online marker detection system deployed by EPRI aims to provide insights into new marker dynamics in a working transformer. Further exploration into new marker dynamics will be performed, providing the industry with enhanced value from oil samples and greater insights into transformer conditions.