Each day more stringent regulations demand from users the ability to demonstrate high reliability for all critical components. Reliable transportation of power transformers requires design adequacy to withstand hard to predict mechanical forces. Railroad transportation poses special challenges to currently available diagnostics methods. We will review the experiences of Prolec GE in this regard. By understanding these issues, the transformer purchaser and supplier can mitigate problems before they occur.

Authors: Enrique Betancourt, Prolec GE- Sept. 30, 2008

When a transformer failure happens, invariably one or more of the following types of losses occur: 1) Property Damage - Fire /Explosion, 2) Equipment Breakdown, 3) Business Interruption, 4) Personal Injury, 5) Product Liability, 6) Environmental Damage - any one of which can lead to large dollar claims and ensuing litigation. Thus the CAUSE, ORIGIN and REASON for the Transformer failure needs to be understood by Manufacturers, Maintenance and Asset Managers, Claims and Risk Managers, Lawyers and the rest of the Litigation Community of Plaintiffs, Defendants, Judges and Juries in order to Opine on the RESPONSIBILITY for the loss. Prevention of transformer failures can be a lot easier if the cause and reasons from other failures are understood. In this presentation Prof. Brosz will show cases and examples of a wide variety of transformer failures including: ARC FURNACE, RECTIFIER, DRY and OIL TYPE, 735 KV and less , SHELL TYPE and CORE TYPE, CONTROL, POLE TOP, and SUBMERSIBLE. Some of these losses will involve personal injury. Forensic investigation standards, procedures and methodologies including preservation of evidence issues will be addressed.

Author: Professor Helmut G. Brosz, Brosz & Associates - Sept. 30, 2008

This paper discusses the differences in temperature measurement among three infrared (IR) cameras with different spatial resolutions. The targets used were actual field problems. This was not a laboratory experiment, but a real-world test of these cameras. Images were taken under the same conditions at the same distance with all the IR cameras. The results show there can be dramatic differences in temperature readings illustrating the importance of adequate resolution when making temperature measurements with IR cameras.

Author: Eric Davis, FLIR - Sept. 30, 2008

On-Line Dissolved Gas Analysis has been used successfully for many years in main tanks of power transformers using established industry guidelines for diagnostics. The capability to measure both the main tank and Load Tap Changer with one DGA unit is now available to provide complete monitoring of the transformer. In this presentation Mr. Cox will review the technology utilized to provide this unique solution for DGA in load tap changers, particularly for continuous monitoring.

Author: Randy Cox, Kelman - Sept. 30, 2008

Does transformer oil ever reach a point where it does not make sense to reclaim? Dr. Jakob will address this question and propose a diagnostic method to determine the reclaimability of the oil through the use of carbonyl detection and analysis.

Author: Dr. Fredi Jakob, Weidmann Diagnostic Solutions - Sept. 30, 2008

Transmission systems are being more heavily loaded and are being operated in ways not originally envisioned. In addition, transmission systems must be flexible enough to react to more diverse generation and load patterns. In this keynote presentation Mr. Mader will review Entergy’s activities in applying Flexible AC Transmission Systems on its transmission grid. The use of FACTS allows Entergy to have more transmission system control which will improve asset utilization, allowing more power over existing transmission lines, as well as improved system flexibility and performance.

Author: KEYNOTE SPEAKER – Douglas J. Mader, Entergy - Sept. 30, 2008

As the cost and lead-time for new substation equipment continues to increase the alternative approach of upgrading your existing substation assets becomes more attractive. Mr. Feghali will review some of the equipment retrofitting and refurbishment projects in which his company has been involved.

Author: Pierre Feghali, North American Substation Services - Sept. 30, 2008

The issue of corrosive sulphur in insulating fluids has become an important performance topic, over the past few years, in the electrical transmission industry. There have been reports of numerous failures of large transformers linked to corrosive sulphur believed present in naphthenic mineral oils used as the insulating fluid. Much work has been done to create new methods of detecting corrosive sulphur in transformer oils. This paper focuses on the technology for production of severely refined, sulphur free blending materials for the formulation of a new generation of transformer fluids. It covers the formulation, evaluation and performance characteristics of paraffinnic transformer fluids manufactured from corrosive sulphur free, iso-paraffinnic base oils. It will be shown that these fluids can pass latest corrosive sulphur test methodology without the use of passivator additives. In addition, it will cover increased oxidative stability, heat transfer and biodegradability characteristics when compared to common naphthenic mineral oils.

Author: Steve Krawiec, Petro-Canada - Sept. 30, 2008

Because mineral oil has been used as the primary dielectric fluid in oil-filled equipment for the past century, there is a significant amount of diagnostic data and interpretation methodology in existence. Natural Ester based dielectric fluids are being used in greater numbers for new and retro-filled transformers. In this presentation Mr. McShane will review the differences between Mineral Oil and Natural Ester Fluid in regards to diagnostics based on oil sampling. He will review a recent IEEE guide, C57.147 “Guide for Acceptance and Maintenance of Natural Ester Fluids in Transformers” which was published in July, 2008.

Electrostatic precipitators (ESPs) are critical to the clean delivery of electric power as well as controlling particulate emissions from various industrial processes. The transformer/rectifier is a major component of the power supply system to the ESPs. The failure of a transformer/rectifier can limit the performance of the ESP system and in the case of a power plant ultimately limit the permissible output power of the station. As the Environmental Protection Agency enforces compliance with its Clean Air Act, the importance of the performance of the ESP transformer/rectifier has risen. In this presentation Mr. Field will review a diagnostic analysis methodology based on oil analysis that is being developed to assess the condition of the Transformer/Rectifier.

Author: Norman Field, Weidmann Diagnostic Solutions Inc.- Sept. 30, 2008

Frequency Response Analysis measurements are becoming an accepted method for condition assessment of Power Transformers. The method is based on comparisons between 1. Measurements performed on the same transformer over time, 2. Measurements on sister transformers (transformers of same design) and 3. Comparisons of measurements between phases in the same transformer. This means that measurement repeatability is of outmost importance in order to secure the full value of the investment made in time and equipment when performing these tests. In this presentation Mr. Karlstrom discusses the influences external parameters such as cable practices, accuracy and equipment variations may add to the measurements and therefore complicate the interpretation and ultimately the value of the test. Theoretical explanations are backed up by field experience and measurements. Typical sources of errors are discussed and recommendations on how to prevent these errors and achieve highest possible repeatability in SFRA measurements are suggested.

Author: Mats Karlstrom, Pax Diagnostics - Sept. 30, 2008

In a previous paper we reported on the work to evaluate various methods for detecting when electrical contacts have worn to a point at which they should be changed. The design concept is to imbed a dissimilar metal or liquefied trace material implant within the contact at a predetermined depth and to detect it when the implant is exposed or breached by arcing or wear. Various methods for detection have been evaluated and refined for use. This paper presents the results of accelerated in-service beta testing and provides an update of the continued research to validate reliability of the methods selected for use. It also describes the development of a new online multifunctional monitor that will reliably detect contact wear, heating and coking.

Recent improvements in diagnostic testing allow the transformer owner to make critical decisions concerning the condition of the insulation system without having to do an internal inspection. In this presentation Dr. Patel will review the Dielectric Frequency Response (DFR) measuring technique and the interpretation of the measurements. Case studies will be presented where transformers having abnormal DGA were tested using DFR techniques. Analysis of the results, were then used to identify the root cause of the problems allowing for repairs to take place.

Author: Dr. Poorvi Patel, ABB Inc. - Sept. 30, 2008

Although considered old technology there are still a significant number of oil circuit breakers in operation. Because their operation is critical to the power system, maintenance of these components is crucial. Diagnostic evaluation of oil samples gives valuable information to the asset owner so that maintenance can be based on the condition of the equipment. In this presentation Mr. Prevost will review the methodology used for OCB diagnostic analysis and present some case histories that demonstrate the effectiveness of this approach.

Most of the electrical systems in the US are aged, with at least half of the equipment over forty years old. At the same time this equipment is being loaded at increasing levels as the demand on the system continues to rise. In this presentation Mr. Salinas will describe the strategy that Southern California Edison utilizes to maintain the critical equipment on its system with a limited budget.

Water is one of the worst contaminants that are found in transformers. There is always some water in the insulation system. The quantity of water can increase over time due to many factors, including the aging process of the cellulose insulation itself. In this presentation, Mr. Kabrich will review the effect of water on the insulation system. He will address how the water gets into transformers, how to measure the amount of water and finally what to do about it once you know how much is there.

There are many existing methods of evaluating condition, calculating useful life, and predicting the need for maintenance. Some plan maintenance on the basis of: “Tell me today what will fail tomorrow”. A combination of on-line and off-line methods can be utilized to help make this call. In this presentation Mr. Wagner will review the factors to be considered when evaluating IEDs such as the cost of the equipment including installation, maintenance and calibration, ease of data access and interpretation, warranty and customer support.

After twenty years of age, transformer failure probability more than doubles every ten years. For highly loaded or overexcited units, problem events are likely to be more frequent. As probability of failure rises, frequency of testing should also be increased to mitigate added risk and associated cost of operation. The increased cost of testing requires cost justification that can be balanced by the reduced risk of failure. Consequences related to the level of criticality placed on the unit, and the impact that a failure of the unit will have, are discussed. This paper also provides methods of determining changes in failure probability over time, along with criteria for assessing ways to calculate risk and savings associated with risk mitigation.