Approach to Mitigating Risk of Transformer Failure Improves Asset Management

In 2011, a critical power transformer unexpectedly failed at one of Salt River Project’s (SRP) vital receiving stations, resulting in a large-scale outage. An analysis determined the cause to be related to a bushing failure. Further analysis of historical outage data indicated that a significant proportion of SRP’s critical power transformer failures – particularly at high voltage levels – were due to bushing failures.

Therefore, SRP commissioned Black & Veatch to review the way SRP manages its 230 kilovolt (kV) and 500 kV transformer fleet. The review was to consider the complete asset life cycle, examining how SRP engineers design, install, maintain and manage these critical assets that contribute to overall system performance.

PAS 55

SRP and Black & Veatch decided to undertake the review using Publicly Available Specification 55 (PAS 55). PAS 55 provides an essential, objective definition of what is required to demonstrate competence and establish improvement priorities. PAS 55 also makes clearer connections between strategic organizational plans and the actual day-to-day work and asset realities.

Effective asset management is all about achieving the appropriate balance between cost, risk and performance. Black & Veatch’s focus was to provide results that could be used to manage SRP transformer-related risks now, as well as providing a road map for asset management process improvement in the future.

Black & Veatch’s professionals worked with SRP’s internal team that was reviewing transformer failure from a technical point of view. Together, they developed recommendations that led to the application of best practices as defined by PAS 55.