توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱In service insulating liquid, retain, recondition, reclaim or replace Reactance Using Potier Approximation
نویسنده(ها): ،
اطلاعات انتشار: بیست و یکمین کنفرانس بین المللی برق، سال
تعداد صفحات: ۹
In service insulating liquid are subjected to thermal and electrical stress, consequently decompose produce oxidation by products. The oxidation by products is affecting electrical and physical properties of the liquid, reducing their cooling efficiency and ability to act as insulating liquid. Heavily oxidised oil has low cooling property, leading to transformer overheating damaging solid insulation system and transformer failure.
Clearly such oil is not fit for the purpose and remedial action is required. While there are several options available to the equipment owner, to rectify the situation, but making correct decision is technically and economically important since it may affect life of the system. Among these options are; reclaiming the oil, replacing the oil, recondition the oil or retain the oil. In order to be able to make such decision a nd make sure
correct decision is made, the oil must be tested and certain limits for test results are required. Additionally risk analysis, cost analysis and benefit of each option should be considered to be able to select the best available option.<\div>

۲Maintenance decisions enabled through oil testing
نویسنده(ها): ،
اطلاعات انتشار: بیستمین کنفرانس بین المللی برق، سال
تعداد صفحات: ۶
One of the most important tools in a condition based maintenance strategy is to have a convenient, reliable and cost efficient method to identify deteriorating condition of a transformer. This method shall preferably be applicable whilst the transformer is on–line. Such a method will reduce the need for invasive maintenance substantially. For transformers, their tap changers, bushing, diverter and oil breakers this tool is the analysis of an oil sample, usually performed in a well equipped off site laboratory. Pump wear, abrasion, overheating, paper and oil ageing, discharge and arcing can all be diagnosed from such a test. An oil sample is taken in periodic intervals, depending on the asset condition and sent to aboratory for analysis. Results from the oil analysis are used to diagnose and assess the condition of the unit.

۳Revised IEC Standard for Maintenance of in Service Insulating Oil
نویسنده(ها): ،
اطلاعات انتشار: نوزدهمین کنفرانس بین المللی برق، سال
تعداد صفحات: ۱۱
For reliable operation of oil–filled electrical equipment, monitoring and maintenance of insulating liquid is essential. Mineral insulating oil is the most widely used insulating liquid for cooling and insulation in oil–filled electrical equipment. The characteristics of the oil, supplied as unused, may change during service life. Therefor, the oil quality should be monitored regularly during its service life. In many countries power companies and electrical power authorities have established codes of practice for this purpose. In general these cover monitoring guidelines and corrective
actions depending on the oil status. If a certain amount of oil deterioration is exceeded then the possibility and risk of premature failure should be considered. While the quantification of the risk can be very difficult, a first step involves the identification of potential effects of increased deterioration. IEC60422 is guide for supervision and maintenance of mineral insulating oils. This standard is now revised to take account of changes in oil and equipment technology and has due rega rds, for the best practices currently in use, worldwide. Changes are also made to use current methodology and comply with requirements and regulations affecting safety and environmental aspects.<\div>

۴Revised IEC specification for supply of unused oil
نویسنده(ها): ،
اطلاعات انتشار: هجدهمین کنفرانس بین المللی برق، سال
تعداد صفحات: ۸
International standard IEC60296 is used in electrical industry for purchasing and supply of unused mineral insulating liquid. The previous issue was revised and published in 1982 and since then quality of the oil and expectation for performance ofthe oil in service has improved tremendously. It is one of the most widely used standard for supply of oil in the electrical industry. Although it is well established, the limits and
expectations are very low, therefore many low quality oils may pass the requirements of this standard. Both users and producers realized this shortcoming, therefor during IEC TC10 general meeting in 1998, it was decided to revise this standard. The standard was revised and circulated as CD and later on as CDV taking the national committees recommendation into consideration. This document was finally sent to IEC central
office as CDVF for publication. The revised standard prevents low quality oils from entering the market by having different limits for oxidation stability, depending on their antioxidant concentration. The limit for viscosity is also changed to improve cooling efficiency and to fulfil today's
cooling requirements of the oil. A viscosity of higher than 12 cSt at 40 °C is not considered to be acceptable. In respect of other parameters there is a new section for specific requirements for specific applications. In this case the important property of oxidation stability has extremely high requirements. In addition to high oxidation stability, the oxidized oil should have low DDF to ensure suitability of the oil in service to act as insulation liquid. Environmental, health and safety parameters have been introduced to have safer products for the user and to fulfil today's legislative requirements. The paper looks at the implication of the new standard for the users, the producers and the technology involved.<\div>

۵Development of techniq ue for decontamination of soil fromspilled oil in substations
نویسنده(ها): ،
اطلاعات انتشار: چهارمین همایش کیفیت و بهره وری در صنعت برق، سال
تعداد صفحات: ۱۰
The presence of organic hydrocarbon contaminants in soil continues to be a cause of concern. The contamination is usually due to oil spillage or leakage from transformers. Although every effort is made to minimise spillage, during handling of insulating oil, but accidents can happen resulting in land and water contamination. The clean up of
insulating oil spill or oil contaminated with PCBs is costly to electricity industry and labour intensive. In the other hand there is requirement and legislation to clean contaminated sites from spilled hydrocarbons specially those with high water table. Several decontamination techniques available fulfil this commitment. Chemical treatment offers some advantages over the existing methods. This paper reviews different available techniques for soil clean up. It is also reporting a newly developed chemical technique for decontamination of soil from hydrocarbon and PCBs. It is fast, environmental friendly, economy and can be used on site.<\div>
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