• Utility Engineering Topics
  • Utility Operations Topics

Utility Engineering Topics

Topic # Topic Title Definition
1 Transformer Design General description of transformer design process from Request for Quote to final release for manufacturing. Some of the key subjects include design optimization, magnetic circuits, electrical coils, and mechanical/structural designs. Also included are calculations of several key performance characteristics such as short-circuit forces, temperature rises, and losses.
2 How to Conduct a Design Review with a Manufacturer (a) What parameters are important
(b) What processes/practice should be reviewed during a plant trip
(c) What reference documents can we recommend/supply
3 Electrical Design Process More detailed description of how transformer designs are optimized for each customer and how the final design is verified to meet the specifications and guaranteed performances before it is released to the Mechanical design process and procurement.
4 Mechanical Design Process More detailed description of mechanical designs to meet the specifications. Major tools used for mechanical design are explained in detail with many examples. Designing for easy assembly and minimum maintenance as well as shipping restrictions are also presented
5 Transformer Specifications Minimum information required to describe the transformer you need is explained. Also included are the latest industry standards and recommended optional items for long-term reliability.
6 Transformer Loading / Thermal Design Issues Principles of thermal design and the process of insulation aging in power transformers; and how each of these principles affects the life of the transformer. This will assist the engineer in decisions about loading and asset management decisions in the operation of substation transformers.
7 Transformer Magnetic Circuit The magnetic circuit design is vital to ensuring proper operation of a modern power transformer. The presentation will review the material and design options and their impacts on transformer operation.
8 Short Circuit Forces Power transformers must be designed to survive the affects of through faults during the operation of the utility grid. This presentation will cover the theory of design to ensure the ability of the transformer to survive these faults as required by current industry standards.
9 Transformer Monitoring Starting from the industry statistics on transformer failures, a good categorization of physical quantities to monitor is made. Based on probability and consequence of failures, what to monitor and how often to monitor can be technically and economically determined. Some very good listing of commercially available monitoring system is presented also.
10 Fundamentals of Insulation Design Design principles use for the dielectric insulation system of the windings and core and coil assemblies for power transformers. This will give the engineer training in the specification of dielectric levels when specifying power transformers.
11 Impedance Design The specification of the correct impedance affects short circuit withstand, voltage regulation, load sharing and other system characteristics. Impedance is critical and the presentation will provide an understanding of the selection and specification of impedance to ensure the transformer will be suitable for operation in the utility system.
12 Sound Level Control Basic theory of sound generation, transmission, and measurements are covered in detail. Industry standards on maximum sound pressure levels and sound power levels are described. Techniques typically used on new transformers are included with expected reduction. Active and passive noise reduction for new and existing transformers are included with general discussion on "near field" vs. "far field" sound levels.
13 Water in Transformer Issues – Insulation Degradation General discussion on why the water in transformer is bad, how the water gets in, methods to determine how wet the transformer is, and what the owner can do to minimize the total water inside.
14 Tap Changers – DETC & LTC Design, Operation & Applications: Load tap changers operating principles are presented to provide the utility engineer with the advantages and limitations of the various types of load tap changer mechanisms available in the market. The engineer will be able to evaluate the operation principles and prepare specifications to ensure satisfactory operation on the utility system.
15 Winding Design Transformer winding design affects thermal performance and short circuit withstand of the substation power transformer. This presentation will provide the utility engineer useful information in the preparation of transformer specifications.
16 Factory Testing A review of the testing of substation power transformers as required by current IEEE standards and optional tests which the utility engineer should consider. The utility engineer needs a thorough understanding of transformer testing to ensure proper specification and testing both in the factory and field acceptance process.
17 Nominal Voltage & Over Excitation Continuous over excitation of power transformers affects transformer sound level and impedance, which can result in operating constraints for the utility system. The system engineer will gain an appreciation of the results of operating the transformer above its nominal voltage rating.
18 Magnetic Cores
Stray Losses
Leakage Flux Control
Total flux generated inside the transformer is distributed throughout the transformer, mainly through the magnetic core. Any flux that does not flow through the main core is called leakage flux and it causes additional losses within the windings, leads, and other metallic components. Modern techniques to analyze and manage these leakage fluxes are explained with examples.
33 Standards Updates IEEE and ANSI


Utility Operations Topics

Topic # Topic Title Definition
19 Dissolved Gas Analysis Dissolved gas analysis is a valuable tool used to determine the condition of the internal core and coil assembly by the production of various hydro carbon products during operation. This course reviews some common analytical and sampling techniques along with how to interpret information for decisions regarding maintenance and resolution of the cause of the combustible gas production.
20 Field Acceptance & Testing A review of recommended field acceptance testing prior to initial energization of a power transformer and periodic maintenance testing. The review includes test methods, acceptance limits, and diagnostic routines when suspect results are obtained. Review covers Insulation Power Factor (Doble), TTR, DC Resistance, Winding Excitation, Insulation Resistance (Megger), Dew Point, and SFRA testing.
21 LTC Maintenance Procedures A review of the proper method of inspection, testing and maintenance of load tap changers to ensure proper operation on the utility system.
22 Condition Assessments During the service life of a substation transformer, it is necessary to access the effects of transformer operation and determine when replacement or maintenance is required.
23 Oil Preservation Systems Three most common systems for power transformer oil preservation are described: Sealed type, Nitrogen blanketed, and Conservator. Advantages and disadvantages of these systems are discussed based on costs, maintenance required, and performances.
24 Corrosive Sulfur in Oil Corrosive sulfur had been known to exist in mineral oils for many decades. Recently, many transformer failures are claimed to have been caused by corrosive sulfur. Recent technical papers and presentations on this subject are summarized. Industry guides and standards are listed with some historical background information. A manufacturer’s position on this subject is also included.
25 Life Extension A review of the maintenance practices and specific life extension efforts that can address thermal, mechanical and component issues that can help extend the service life of the transformer in lieu of replacement.
26 Natural Ester Fluids How to dry your transformers out by simply retrofilling with natural ester fluid. How does it work? Presentation describes how natural ester fluid dries cellulose insulation and slows the aging process extending the life of the asset.
27 Field Processing (Vacuum Oil Filling/Dry Out) A review of the recommended practices for oil processing of power transformers, including discussion on moisture determination, field dry out of transformers, oil reclamation and vacuum filling.
28 Transformer Re-gasketing Oil leaks are one of the biggest maintenance issues for owners of Power Transformers. This session reviews the most common sources of oil leaks and methods to correct and repair. Discussions cover type of material, application information, and preparation.
29 Field LTC Retrofits A review of the consideration and process for converting reactance-bridging load tap changers to vacuum switching tap changes to decrease maintenance intervals, relieve issues with obsolete parts, and improve availability of equipment.
30 LTC Rebuilds & LTC Contact Lease Kits LTC maintenance often involves inspection followed by periods of time when equipment is out of service while waiting upon necessary replacement parts. This class reviews an innovative approach to LTC maintenance where model specific components can be pre-kitted and made available prior to inspection to assure immediate availability of parts to reduce downtime. In shop rebuild and redesign practices are also discussed when critical tolerances, timing, and material compatibility must be maintained.
31 Transformer Components A review of the benefits of the selection and operation of components necessary to enhance the transformer operation and reduce the maintenance requirements during the life of the transformer.
32 Asset Management A review of recommended transformer commissioning practices, including receiving inspections, rigging and lifting, field assembly, oil processing, and commissioning tests.
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