The IEEE Transformers Committee has been very active this past year, with back-to-back record attendance for the fall and spring meetings. In March, 659 people from around the world met in Texas to help develop transformer standards and guides as the U.S. power industry continues to remain a key interest globally.
INSULATING FLUIDS SUBCOMMITTEE
This subcommittee has been very active and is scheduled to publish multiple guide revisions and a new guide this year. Following is a partial list of the activities.
C57.166
C57.166 is the new guide for the Acceptance and Maintenance of Insulating Liquids. It is a consolidation of all fluid-quality testing and will also include synthetic esters. This guide is out for publication and will replace the following guides: C57.106, IEEE Guide for Acceptance and Maintenance of Mineral Insulating Oil in Electrical Equipment; C57.147, IEEE Guide for Acceptance and Maintenance of Natural Insulating Liquid in Transformers; C57.111, IEEE Guide for Acceptance of Silicone Insulting Fluid and its Maintenance in Transformers; and C57.121, IEEE Guide for Acceptance and Maintenance of Less-Flammable Hydrocarbon Fluid in Transformers.
It’s important to note that with this revision, the ASTM D-877 dielectric test for in-service transformers is no longer approved for analyzing the fluid. The ASTM D-1816 methodology is the only approved dielectric test.
C57.146
The working group for C57.146, IEEE Guide for Interpretation of Gasses Generated in Silicone-Immersed Transformers, has completed the guide revision after analyzing approximately 165,000 dissolved gas samples. It has established new threshold limits similar to C57.104 (for mineral oil DGA) for the 90th and 95th percentile values of each dissolved gas. The revision is awaiting publication.
C57.637
The working group for C57.637, IEEE Guide for the Reclamation and Reconditioning of Insulating Liquids, has finalized the revision and is expanding beyond mineral oil to include natural esters, synthetic esters, silicone, and less flammable hydrocarbons. This guide references the C57.166 guide; after C57.166 is published, the approval process for C57.637 will resume so it can be published this year.
BUSHINGS SUBCOMMITTEE
The working group for C57.19.01, IEEE Standard for Performance Characteristics and Dimensions for Power Transformer and Reactor Bushings, voted to go to ballot for the guide revision.
The working group for C57.19.04, IEEE Standard for Performance Characteristics and Dimensions for High Current Power Transformer Bushings with Rated Continuous Current in Excess of 5000 A in Bus Enclosures, has also completed its first ballot and received 100% approval.
A presentation made during the Bushing Subcommittee raised the concern about C1 power factor variances that occur during transformer installations compared to the factory nameplate data. A motion was made and accepted to form a task force to explore the concept of determining what is considered acceptable for bushing testing on new installations.
DRY-TYPE TRANSFORMERS SUBCOMMITTEE
The Dry-Type Transformers Subcommittee has also been very active. Six of the 14 standards are under revision and are expected to be published this year. Following is a list of those under review.
- IEEE C57.12.01, Standard for General Requirements for Dry-Type Distribution and Power Transformers, has gone to ballot and is undergoing comment resolution to address negatives to the ballot.
- IEEE C57.94, IEEE Recommended Practice for Installation, Application, Operation, and Maintenance of Dry-Type Distribution and Power Transformers, has been approved and is awaiting publication.
- IEEE C57.12.59, IEEE Guide for Dry-Type Through-Fault Current Duration, is preparing to go to ballot by the working group for approval and commenting. It is expected to be approved for publication later this year.
- IEEE C57.12.91, IEEE Standard Test Code for Dry-Type Distribution and Power Transformers, is awaiting IEEE approval before it can be published.
- IEEE C57.96, IEEE Guide for Loading Dry-Type Distribution and Power Transformers, has gone to ballot and comment resolution. The working group is preparing for the recirculation of the guide revision.
- IEEE C57.16, IEEE Standard for Requirements, Terminology, and Test Code for Dry-Type Air-Core Series-Connected Reactors, has been approved and is awaiting publication.
OTHER INTERESTING IEEE COMMITTEE UPDATES FOR NETA MEMBERS
C57.152
Within the Standards Subcommittee, C57.152, IEEE Guide for Diagnostic Field Testing of Fluid-Filled Power Transformers, Regulators, and Reactors, has been approved for publication. The purpose of this guide is to provide users with a document on what electrical testing should be performed throughout the life of a transformer. It is expected to be published by this fall.
C57.93
Within the Power Transformers Subcommittee, a revision to C57.93, IEEE Guide for Installation and Maintenance of Liquid-Immersed Power Transformers and Reactors, is underway. An addendum to C57.93 was added this past year. The addendum is a cold start-up procedure for natural-ester liquid-filled power transformers for freezing temperature conditions. Since natural esters have such a high pour point, the fluid solidifies under extreme freezing conditions.
Scott Reed is President of MVA and is very active with the IEEE Transformers Committee, where he serves as Vice Chairman. He holds three U.S. Patents, has written and published various papers, and regularly speaks at NETA’s PowerTest conferences. Reed earned a BS in electrical engineering from North Carolina State University.