IEEE Transformers Committee Report

Scott Reed, MVAFall 2019 Specifications & Standards, Specifications & Standards

Insulating Fluids Subcommittee

C57.104, IEEE Guide for The Interpretation of Gases Generated in Oil-Immersed Transformers (DGA) has undergone a significant revision that completely changes how DGA results should be interpreted for mineral-oil filled transformers.  The last time the guide was revised was 2008. It has gone through numerous draft versions and multiple ballots, and hundreds of comments have been reviewed. The final draft went out for ballot in March 2019, and the comments were reviewed and voted on at the last IEEE Transformer Committee working group meeting on March 26, 2019. The next step is to submit the revised guide to IEEE for review and approval. If accepted, the guide is expected to be published later this year.

C57.166. The new Working Group for IEEE Guide C57.166, Guide for Acceptance and Maintenance of Insulating Liquids in Transformers and Related Equipment, continues to make progress. This new guide will incorporate and establish fluid quality thresholds for all fluid types. Currently, users have to reference a separate guide for a specific fluid type to research the minimum acceptable values. This guide will simplify accessing data for end-users. Much development work remains to be done regarding this new guide.     

C57.146. Because of the high interest in C57.146, IEEE Guide for Interpretation of Gasses Generated in Silicone-Immersed Transformers (primarily for industrial plant applications), it was decided to keep the guide active and to renew the par scheduled to expire December 31, 2021. A working group will be organized to start the review. However, since the information from C57.111, IEEE Guide for Acceptance of Silicone Insulating Fluid and Its Maintenance in Transformers and C57.121, IEEE Guide for Acceptance and Maintenance of Less-Flammable Hydrocarbon Fluid in Transformers will be included as part of the new C57.166 guide, it was decided to let these pars expire.

Power Transformer Subcommittee

C57.93, IEEE Guide for the Installation and Maintenance of Liquid Immersed Power Transformers was republished. This guide covers the installation and maintenance of transformers that are 501 kVA and larger, with a secondary voltage of 1,000 Volts or higher. The guide includes pad-mount and network transformers, but does not include specialty transformers such as furnace or rectifier transformers.   

Transformer Condition Assessment Task. This task force met to continue to determine the title, scope, and purpose of this new guide so it can be a useful tool for performing a transformer condition assessment. The scope of the guide is to present existing condition assessment methodologies that quantify the current condition of liquid-immersed transformers, reactors, and their components. After the title, scope, and purpose are finalized, it will be submitted for approval to develop a new guide. If approved, work can begin to develop this new guide.

C57.148. In other areas of the Power Transformer Subcommittee, it was recommended that C57.148, IEEE Guide for Control Cabinets for Power be sent out for ballot. Work continued to develop checklists for design reviews related to transportation, impact recorders, and shipping with natural ester within PC57.150/D10, Guide for the Transportation of Transformers and Reactors Rated 10,000 kVA or larger.

Bushing Subcommittee

A new Bushing Overload Conditions Task Force was created, but is just getting started. In other areas, work continues on C57.19.00, IEEE Guide for The Standard General Requirements and Test Procedures for Power Apparatus Bushings. The goal is to have this revised guide published by 2020.

Dielectric Tests Subcommittee

C57.127, IEEE Guide for the Detection of Acoustic Emissions from Partial Discharges in Oil-Immersed Power Transformers was approved and published. C57.160, IEEE Guide for the Electrical Measurement of PD in HV Bushing and Instrument Transformers went out for ballot, and the group is resolving comments. 

Instrument Transformer Subcommittee

A new Instrument Transformer Accuracy Task Force was formed. The first step will be to develop a title, scope, and purpose for this new group. 

Performance Characteristics Subcommittee

The C57.123 working group for IEEE Guide for Transformer Loss Measurement recommended the guide go out for ballot. The subcommittee approved unanimously. In the IEEE Guide for FRA for Liquid Filled Transformers, work continues toward reviewing grounding practices and fine tuning the analysis section of the test curves to help end-users.

Scott Reed is President of MVA Diagnostics, which specializes in the diagnostic analysis of oil in substation transformers throughout the United States. He received a BS in electrical engineering from North Carolina State University with a concentration in power and joined Baltimore Gas & Electric performing relay system protection design work. Scott serviced transformers, including vacuum filling, oil processing, repairing, electrical testing, and oil testing for 25 years before founding MVA Diagnostics. He has written and published various papers for the industry and is very active with the IEEE Transformer Committee, where he serves as Secretary of the IEEE Insulating Fluids Subcommittee; Vice Chairman of IEEE Std. C57.166, Acceptance and Maintenance of Insulating Liquids in Transformers; and Secretary of IEEE Std. C57.93, Installation and Maintenance of Liquid Immersed Power Transformers.