Progress report on natural esters for distribution and power transformers

Hopkinson, Phil; Dix, Luke; McShane, C.P.; Moore, H. R.; Moore, S.; Murphy, Jerry R.; Prevost, Tom; Beaster, B.

doi:10.1109/pes.2009.5275850

Cited by 19 publications

(11 citation statements)

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“…For years, various research works were carried out on different aspects such as on the safety / environmental, ageing and electrical performances of the vegetable oil [2][3][4][5][6][7][8][9][10][11][12]. Vegetable oil such as natural ester was also successfully applied in-service where it was used from small to medium transformers up to a voltage level of 66 kV [11]. Among the attractive factors of vegetable oil is the non-toxicity and highly biodegradable which ensure low risk to the environment if there is a spillage.…”

Section: Introductionmentioning

confidence: 99%

Suitability of Palm Based Oil as Dielectric Insulating Fluid in Transformers

Azis¹,

Jasni²,

Kadir³

et al. 2014

Journal of Electrical Engineering and Technology

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-Mineral oil has been widely used as dielectric insulating fluid in transformers due to its excellent performance in-service. However, there are few issues with mineral oil such as it has poor biodegradability and could contaminate the environment if a spillage occurs. With the increasing tight regulation on safety and environment, alternative fluids for mineral oil are currently being investigated and among the suitable candidate is the vegetable oil. There are different types of vegetable oils and one of them is the palm based oil. At the moment, extensive research works are carried out to examine its feasibility to be applied in transformers. This paper will review the previous research works that were carried out to examine the suitability of palm based oil as dielectric insulating fluid in transformers. The physical and chemical properties of palm based oil are studied based on viscosity, acidity, oxidation stability and flash point. Next, the electrical characteristics of palm based oil are examined based on AC breakdown voltage, relative permittivity, dissipation factor and partial discharge.

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Section: Introductionmentioning

confidence: 99%

Suitability of Palm Based Oil as Dielectric Insulating Fluid in Transformers

Azis¹,

Jasni²,

Kadir³

et al. 2014

Journal of Electrical Engineering and Technology

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“…Statistical analysis using the Microsoft Office Excel 2003 and OriginPro v.8.6 software packages has shown that the data is normally distributed allowing calculation of the standard deviation of the breakdown voltage and this has been used to estimate the 1, 10, 50 and 90% breakdown probability for each liquid. This data is relevant to the design of power and pulse power equipment, [5][6][7][8][9][10][11], as it affects safety-margin design requirements for liquid-insulated, high-voltage equipment. Values of the effective mobility of the charge carriers in the liquids were obtained from pre-breakdown I-V characteristics, measured in a point-plane electrode topology, following the procedure reported in [12].…”

Section: Introductionmentioning

confidence: 99%

Dielectric properties of natural ester, synthetic ester midel 7131 and mineral oil diala D

Timoshkin

Wilson

et al. 2014

IEEE Trans. Dielect. Electr. Insul.

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The insulating liquids used in industrial applications are typically mineral oils. In recent years however, significant attention has been paid to alternative insulating fluids, including synthetic and natural ester liquids. In order to expand their practical applications, it is important to have detailed information on their dielectric properties. In this present paper, the dielectric properties of synthetic ester, Midel 7131; mineral oil, Shell Diala D; and vegetable (rapeseed) oil have been investigated. It has been shown that Midel 7131 has a higher ac breakdown voltage (27.6 kV) as compared with Diala D oil (26.4 kV) and rapeseed oil (24.6 kV). However, the breakdown voltage of the Diala D oil has the smallest standard deviation (7%) amongst the tested liquids (13% for Midel 7131 and 11% for rapeseed oil). Statistical analysis of the breakdown voltages has been conducted and it has been shown that the ac breakdown voltages can be described by a normal distribution. dc I-V characteristics have been measured and the space charge saturation regime has been observed for all three liquids starting from ∼9 kV for positive energisation and ∼10 kV for negative energisation in the point-plane topology. Apparent mobilities of the charge carriers in the tested liquids have been obtained using I 1/2 -V curves; these mobilities can be used for calculation of the space charge influenced distribution of the electric field in liquid insulators stressed with dc voltage. Such analysis can be important for design and exploitation of HVDC power systems.

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“…For many years, various research works were carried out on different aspects such as safety/environmental, ageing and electrical performance of vegetable oil. Transformer filled with vegetable oil were already tested successfully at different voltage level [1]. Among the attractive factors of vegetable oil is the non-toxicity and highly biodegradable, which ensure low risk to the environment if there is a spillage.…”

Section: Introductionmentioning

confidence: 99%