The Development of an Oil-Immersed Surge Arrester for Distribution Transformers

McMillen, C.J.; Comber, M.G.; Hopkinson, R. H.; Schoendube, C. W.

doi:10.1109/tpas.1985.318994

Cited by 6 publications

(1 citation statement)

References 9 publications

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“…The gaps between main insulator and internal surface of porcelain are nowadays filled with oil and resin. Usually a high voltage bushing is made as a condenser type containing several layers of aluminum foil wounded around conductor and immersed in the oil inside the porcelain housing, so called oil immersed paper or OIP [14]. The benefits of the traditional type of bushing are low cost and heat dissipating, while the drawbacks are high maintenance cost, transportation, fire and explosion.…”

Section: B High Voltage Bushingmentioning

confidence: 99%

Porcelain Insulator Maintenance Management for Smart Power Transformer

Phadungthin¹,

Haema²

2015

IJOEE

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Power transformer is one of expensive equipment in electrical power system. Porcelain insulators that are bushing and arrester are one of significant components of the transformer. Failures of the insulators are unacceptable due to catastrophic consequences to the transformer. Hence, this paper aims to present maintenance management of the transformer porcelain insulators by using electrical test results and visual inspection records with scoring and weighting techniques to evaluate their condition. Besides, statistical failures of main components are utilized for weighting number of bushing and arrester in order to calculate the percentage of entire porcelain insulators of power transformers. Loading transformers and tietransformers are selected for the insulator condition assessment. Finally, condition based maintenance strategies of the porcelain insulators for smart power transformers are managed properly by following their obtained condition.  Index Terms-smart power transformer, porcelain insulators, condition based maintenance, diagnostic techniques

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Section: B High Voltage Bushingmentioning

confidence: 99%

Porcelain Insulator Maintenance Management for Smart Power Transformer

Phadungthin¹,

Haema²

2015

IJOEE

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Critical issues in distribution system surge protection

Ros

1988

IEEE Trans. on Ind. Applicat.

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Insulation system protection with zinc oxide surge arresters

Bialek¹

1999

IEEE Electr. Insul. Mag.

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Key Words: Zinc oxide, surge arresters, arrester selection ver since the first lines were strung, electrical storms and other natural phenomenon have caused voltage surges to occur in the connected system. Surges due to lightning and line switching cause instantaneous and incipient failures. As the systems have grown more complex, available fault current levels have risen, requiring sophisticated surge protection schemes.Spark gaps were the earliest form of overvoltage protection. Due to problems with power frequency follow-through current, current-limiting spark gaps with a series impedance were ultimately developed. The silicon carbide (Sic) arresters with magnetically blown spark gaps were the epitome of this form of overvoltage protection. [1,84]. Surge capacitors and inductors were also utilized in certain applications to limit the overvoltages produced in the system.Insulation coordination standards and guides for the application of surge protective devices developed, which provided a basis for the selection of surge protective devices. [21,27,[93][94][95]. These standards required a minimum protective margin for front-of-wave, standard impulse and switching surge levels, which, based on experience, should provide adequate protection for the life of the equipment, typically 30 or 40 years.As the transmission voltage levels increased, the equipment insulation levels decreased. For equipment such as transformers, the ratio of the basic impulse insulation level, BIL, to system voltage decreases with increasing system voltage [92]. While there are many explanations for this decreasing ratio, the need to reduce equipment size and costs along with the awarding of contracts on the basis of lowest cost have been very important. Ultimately, the need for better protective margins drove the surge arrester manufacturers to develop improved forms of surge protection. In 1968, Dr. M. Matsuoka and his colleagues at Matsushita Electric Co. discovered zinc oxide (ZnO) varistors [83].This paper deals first briefly with the Sic versus ZnO arrester arguments that have led to the wide acceptance of ZnO as the arrester of choice in most applications. ZnO fundamentals and performance issues are discussed. This paper is intended to be a brief tutorial on ZnO surge arresters, and Tom Bialek Pacific Gas and Electric Companythe reader is encouraged to consult the reference section and the literature for more detailed informatison [82]. Silicon Carbide limitationsSic arresters have several fundamental limitations: the Sic valve elements, the gaps, and the power follow-through current. The element's nonlinearity coefficient is typically of the range 2 to 6 and also has a negative temperature coefficient [l, 2,20, 841. During arrester operation the valve element impedance decreases, which allows a higher value of power frequency current to flow, which must be cleared by the gaps necessary to isolate the arrester from nominal system voltages. Multiple series current-limiiting gaps are utilized to improve the gap reliability versus , % si...

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The Development of an Oil-Immersed Surge Arrester for Distribution Transformers

Cited by 6 publications

References 9 publications

Porcelain Insulator Maintenance Management for Smart Power Transformer

Porcelain Insulator Maintenance Management for Smart Power Transformer

Critical issues in distribution system surge protection

Insulation system protection with zinc oxide surge arresters

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