Transformer Engineering
MPR Associates delivers exceptional value to our customers on a wide variety of large
transformer projects. Since 1964, MPR’s engineers and scientists have promoted a lasting
culture of technical rigor, individual initiative and ownership, process discipline, and business
integrity. These traits, along with our comprehensive knowledge and experience of power
systems and transformer engineering and procurement, enable MPR to bring a total systems
approach to our customers.
MPR experience includes large and medium power transformer applications for high voltage
substations and switchyards, transmission system interconnection, generator step-up, unit
auxiliary, and station service transformers for fossil and nuclear power generating stations,
industrial facilities, wind farms, and other renewable generation assets.
MPR has successfully completed a wide variety of projects involving transformers with nominal
system voltages from 480 V up to 500 kV. MPR’s experience includes core form and shell form
type units, two-winding and three-winding transformers with de-energized tap changers
(DETCs) and on-load tap changers (OLTCs), dry-type air cooled and oil immersed transformers,
and large and medium power, switchgear and pad-mount transformers.
Our extensive experience and total systems approach includes the full spectrum of
transformer engineering services:
Transformer Sizing and Power System Analysis.
The depth and breadth of MPR’s expertise with power systems analysis enables us to ensure that
functional performance criteria for power transformers are well understood. MPR uses a variety
of specialized software tools, including ETAP®, EMTP-RV, PSCAD®/EMTDC™, and
MATLAB/Simulink®, to simulate and analyze the performance of
transformers under steady-state and transient conditions. The types
of analyses we perform include transformer capacity sizing and
impedance selection evaluations, and reactive capability, load flow,
short circuit, transient loading evaluations, and parallel transformer
evaluations. Our ability to perform comprehensive power system
analysis gives MPR the ability to predict for our customers how
their transformer will perform in the field and provide them
assurance that their design and licensing requirements will be met. Using finite element
modeling techniques, we perform thermal / magnetic evaluations of large power transformers
and isolated phase bus duct (IPBD) installations.
Transformer Procurement and Test Specifications.
When purchasing a power transformer it is essential that the functional and performance
requirements for the unit be clearly and accurately presented to the prospective manufacturers.
MPR has developed comprehensive and detailed technical procurement specifications for a wide
variety of transformers. MPR specifications define the applicable design, manufacturing, quality
assurance, testing, shipment, delivery, and documentation requirements necessary to ensure that
For More Information Contact: Robert M. Carritte; MPR Associates, Inc . 320 King Street . Alexandria, VA 22314 . PH: 703.519.0200
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the transformer is conservatively designed and highly reliable, and interfaces properly with
retained structures, systems, and components.
Bidders’ Proposal Evaluation.
Selection of a supplier should be based on a comprehensive evaluation of their capability to
deliver. MPR helps clients select the best supplier based on the bidders’ ability to comply with
the technical and quality requirements of the procurement documents and their past performance
record. MPR performs quantitative evaluation of transformer losses and operating cost for the
total expected life cycle of the transformer.
Detailed Design Reviews.
MPR performs detailed design reviews prior to release for manufacturer to assure
that the design will provide sufficient capacity and capability under normal and
off-normal conditions, and interface properly with the physical and functional
constraints of the field. MPR’s design reviews cover all aspects of the
transformer design including the customer’s specification requirements, vendor’s
engineering calculations and analyses, dielectric, thermal, and mechanical design
margins, materials of construction, third party supplied equipment, quality
assurance, inspection, and test.
Factory Quality Audit, Inspection, and Witnessing of Tests.
MPR offers a global reach when it comes to transformer vendors and factory audit, inspection
and test services. MPR performs factory audits to assess and pre-qualify manufacturers, evaluate
the adequacy and effectiveness of vendor’s environmental, health and
safety, and quality assurance programs, including compliance with
ISO, 10CFR Part 50, Appendix B and 10CFR Part 21. MPR
conducts in-process inspections and vendor oversight at transformer
manufacturing facilities around the world.
Services include
in-process fabrication inspections, witnessing factory acceptance
testing (FAT), evaluation test data, and quality audits of vendor’s
processes and procedures, review of factory acceptance test reports and commissioning,
operations, and maintenance manuals.
Installation and Commissioning Support.
MPR supports the installation and commissioning of new and
replacement transformers. Our services include development of
detailed installation specifications, alarm reviews, protective relaying
setting calculations, tap changer set point determination, design
changes, test plans for new and retained equipment, site inspections and
general commissioning support.
Condition Assessments, Maintenance and Monitoring Programs.
Aging of transformers is brought about by a combination of electrical, thermal, and mechanical
stresses, sometimes exacerbated by design deficiencies or contamination. MPR brings state of
the art knowledge to transformer condition and risk assessments, trending analysis of historical
operating data, interpretation of transformer oil analysis, including physical and dielectric
For More Information Contact: Robert M. Carritte; MPR Associates, Inc . 320 King Street . Alexandria, VA 22314 . PH: 703.519.0200
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properties and oil dissolved gas analysis (DGA). MPR develops comprehensive, cost effective
maintenance and monitoring that fully satisfies unit reliability needs and the minimum
expectations of equipment insurers.
Failure Analysis, Forensic Engineering, and Root Cause Investigation.
MPR has broad experience in diagnosing transformer problems,
identifying the root cause and contributing causes. Our first
principles of engineering approach to problem solving enables MPR
to integrate forensic evidence, testing results, and analytical studies
to properly diagnose transformer design, manufacturing, and
operation problems and develop the appropriate set of corrective
actions properly balancing the need for return to service and long
term reliability.
"We've worked with MPR for 15 years, they are widely recognized as the best in their field. They
are world-class problem solvers." - Plant Manager
For More Information Contact: Robert M. Carritte; MPR Associates, Inc . 320 King Street . Alexandria, VA 22314 . PH: 703.519.0200
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