“Transformer D2 - Design to Demise”
Hilton Milwaukee City Center
Milwaukee, Wisconsin
June 9 -11, 2008
Course Content:
TRANSFORMER PROCUREMENT
Transformer Specification Writing and Factory Qualification
James Graham – Alliant Energy
One of the keys to getting a quality transformer, which meets your expectations at a
reasonable cost, is to write a good specification. In this presentation Mr. Graham will
provide guidelines and examples that will help the user identify issues that need to be
addressed when writing a power transformer technical specification. Prior to placing an
order for a power transformer it is important to know if the manufacturer has the proper
equipment, design and manufacturing processes in place to provide a transformer which
meets your quality expectations. In many cases it is necessary to inspect a factory prior
to placing them on the bid list. Mr. Graham will cover the key elements that should be
included in a transformer factory qualification inspection.
TRANSFORMER DESIGN AND MANUFACTURE
Transformer Materials
Thomas A. Prevost – Weidmann Diagnostic Solutions
Power transformers are expected to last at least thirty years under normal operation. In
this presentation Mr. Prevost will review the various materials used in oil filled power
transformers. Material properties and their effect on transformer design, operation, and
longevity will be discussed. Major material subjects covered will be: Core Steel,
Conductor, Solid Insulation, and Insulating Fluids. New materials such as natural ester
fluids will also be discussed.
Transformer Design
H. Jin Sim – Waukesha Electric Systems
Power transformers are designed according to the specification provided by the purchaser
and must include the manufacturer’s design practice, and manufacturing capabilities.
Typically each power transformer has its own unique design. In this presentation Mr.
Sim will review the transformer design process including examples from his experience
as a transformer designer.
Transformer Manufacture
H. Jin Sim – Waukesha Electric Systems
The quality of a power transformer is dependent not only on the design and materials but
also on the manufacturing process. In this presentation Mr. Sim will review the various
processes involved in manufacturing a power transformer. He includes many photos
from a factory and identifies those critical processes that need to be closely controlled in
order for the manufacturer to provide a quality product.
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Transformer Factory Inspection
Ron Barker – Power Transformer Consulting
Many transformer purchasers visit the manufacturer to inspect their unit in process. In
this presentation Mr. Barker will review the critical manufacturing processes in regard to
what should be inspected to assure that the manufacturer is meeting the purchaser’s
expectations. Critical areas such as winding clamping, dielectric clearances, electrical
connections, and proper mechanical support will be discussed, with examples and photos
included for illustration.
Transformer Factory Testing
Shirish (Sam) Mehta – Waukesha Electric Systems
Power transformers undergo extensive testing prior to being shipped from the factory.
These tests are intended to verify the design and manufacture of the transformer to assure
that it meets the specification. Test results also can be used as baseline criteria for future
condition assessment. Mr. Mehta explains the various tests that are performed,
concentrating on the critical characteristics of each test.
TRANSFORMER SHIPPING AND RECEIVING
Transformer Acceptance Testing
Rick Youngblood – American Electrical Testing Company
Transformer acceptance testing is performed to determine the condition of the
transformer as it arrived on site. This includes the repeat of some of the factory tests as
well as a detailed review of the seismic shipping record. Acceptance testing also
establishes a baseline of electrical and mechanical characteristics that can be used for
comparisons throughout the life of the transformer. In this presentation Mr. Youngblood
will review specific test procedures that should be included in an acceptance test
program.
TRANSFORMER OPERATION AND MAINTENANCE
Transformer Failures
William Bartley – Hartford Steam Boiler Inspection and Insurance Co.
Unfortunately transformers do fail. It is by studying these failures that we hopefully can
gain a better understanding of the weak areas of a transformer to enhance the design,
operation and maintenance of other transformers. In this presentation Mr. Bartley will
share his experience with transformer failure analysis. He will present several case
studies that point out design and manufacturing deficiencies.
Transformer Normal vs. Abnormal Operation
David Woodcock – Weidmann Diagnostic Solutions
Transformers are designed to last at least thirty years under normal operating conditions.
In this presentation Mr. Woodcock will review what is considered “normal” and what is
considered “abnormal”. He will review several abnormal conditions such as overloading,
short circuits, and their impact on transformer life.
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Auxiliary Component Maintenance and Diagnostic Testing
John Stead – AltaLink Management
Transformer Operation and Loading
Phil Prout - National Grid USA
Transformers are designed and tested to standards, however, when they leave the factory
and placed in service, the transformers are loaded and operated based on the users
loading guidelines and maintenance practices. This paper will highlight how to load and
operate transformers by reviewing factory thermal data and asset health to determine the
loading factor. We will discuss how to load legacy transformers and how to be certain
your new transformers are meeting the requirements. We will review a few units on our
Highly Utilized Transformers (HUT list) and demonstrate what items are reviewed prior
to overloads. Several case studies will be provided and an interactive presentation of
how oil levels change with temperature.
Transformer Life Cycle Analysis
John Stead – AltaLink Management
In order to maximize the life of a transformer a purchaser must be involved in every
aspect of the process: write a proper specification, select an appropriate factory, follow
the process from design to manufacturing verification. After the purchaser has accepted
shipment of the unit it becomes the responsibility of his operation, maintenance and
monitoring protocols. In this presentation Mr. Stead shares his experiences with
transformer life enhancement from protection to maintenance and monitoring. Several
case histories are presented which illustrate his points.
Field Processing of Power Transformers
Derek Baranowski – Baron USA
Whether due to atmospheric contamination or the byproducts of aging, the water content
of transformers will increase with age. At some point it may be desirable to remove this
moisture as well as any particles from the transformer oil. Mr. Baranowski will discuss
the pros and cons of different methods of field processing transformers.
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TRANSFORMER END-OF-LIFE
Transformer Condition Assessment
Craig Stiegemeier – TRES at ABB, Inc.
Whether because of service age or abnormal operation, it is often necessary to assess the
current condition of a power transformer. The information obtained by such an
assessment can be used to decide whether to change the operation of the equipment
(reduce load), perform maintenance or field upgrades, remanufacture, or replace the
equipment. In this presentation we will review condition assessment methodology,
including the various tests that are typically included in condition assessments and what
can be learned from these tests.
Transformer Remanufacturing and Renewal
Bruce Forsyth – Southwest Electric Company
In many cases a transformer can be remanufactured so that it will have a life expectancy
similar to a new unit. However, this is not always the case. In this presentation Mr.
Forsyth will review the remanufacture and renewal process. He will cover those critical
areas that must be reviewed in order to determine if your transformer can be
remanufactured so that it will be as good as new.
Transformer Repair or Replace
James Graham – Alliant Energy
As a transformer reaches the end of its life, either due to field failure or condition
assessment, the transformer owner is faced with a decision of whether to repair or replace
this equipment. In this presentation Mr. Graham reviews the various options available to
the transformer owner when a transformer has reached its end-of-life. He will share
some of his personal experiences including case histories of times when he was faced
with this decision. He will review the steps that should be taken to decide which direction
to take - repair or replace.
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