Influence of temperature and thermal aging on breakdown voltage of oil-paper insulation

2016 ◽  
Author(s):  
Hehuan Ran ◽  
Jian Li ◽  
Jing Zhang ◽  
Xudong Li ◽  
Junsheng Chen
Keyword(s):  
Breakdown Voltage ◽  
Thermal Aging ◽  
Influence Of Temperature ◽  
Paper Insulation

scholarly journals Comparative Study on the Thermal-Aging Characteristics of Cellulose Insulation Polymer Immersed in New Three-Element Mixed Oil and Mineral Oil

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1292 ◽  
Author(s):  
Dawei Feng ◽  
Jian Hao ◽  
Ruijin Liao ◽  
Xin Chen ◽  
Lin Cheng ◽  
...  
Keyword(s):  
Comparative Study ◽  
Breakdown Voltage ◽  
Thermal Aging ◽  
Cellulose Degradation ◽  
Mineral Oil ◽  
Aging Rate ◽  
Cellulose Paper ◽  
Paper Insulation ◽  
Cellulose Insulation ◽  
Insulation Oil

Cellulose paper, whose main component is cellulose polymer, has been widely used in oil-immersed power transformer that gradually deteriorates during transformer operation. Thermal aging is the main degradation form for cellulose paper immersed in insulation oil (oil–paper insulation) in a transformer. One of the most challenging issues in oil–paper insulation is inhibiting the aging of cellulose paper and extending its life. In this work, a comparative study was conducted on the thermal-aging characteristics of cellulose paper immersed in a novel three-element mixed insulation oil and mineral oil at 130 °C for 150 days. The key parameters of cellulose paper were analysed, including the degree of polymerization (DP), thermal-aging rate, surface colour, and AC breakdown voltage. The furfural content and acidity of the oil, as well as the AC breakdown voltage of the insulation oil were also analysed. The results show that the cellulose paper immersed in novel three-element mixed insulation oil had much higher DP values than that immersed in mineral oil after the same thermal-aging time. The mixed insulation oil could significantly inhibit the thermal aging of cellulose paper and prolong its life. The thermal-aging rate of the cellulose insulation polymer immersed in mixed insulation oil is significantly lower than that immersed in mineral oil, whether in the process of oil–paper insulation continuous aging or in the process of aging after oil replacement with unused insulation oil. The furfural generated by cellulose degradation in the novel three-element mixed insulation oil was also less than that in the mineral oil. The mixed insulation oil had a higher acidity value during the thermal-aging process, which was mainly due to the natural esters in the components of the mixed insulation oil. However, the AC breakdown voltage of the mixed insulation oil was always higher than that of the mineral oil. This study offers a new perspective in inhibiting the thermal aging of cellulose polymer in insulation oil.

Effects of thermal aging on moisture equilibrium in oil-paper insulation

2018 ◽  
Vol 25 (6) ◽  
pp. 2340-2348 ◽  
Author(s):  
Dongyang Wang ◽  
Lijun Zhou ◽  
Xianlang Li ◽  
Yi Cui ◽  
Huize Li ◽  
...  
Keyword(s):  
Thermal Aging ◽  
Paper Insulation

Influence of metal transformer materials on oil-paper insulation after thermal aging

2019 ◽  
Vol 26 (2) ◽  
pp. 554-560 ◽  
Author(s):  
Deng Wang ◽  
Zhiping Zhu ◽  
Li Zhang ◽  
Yihua Qian ◽  
Wei Su ◽  
...  
Keyword(s):  
Thermal Aging ◽  
Paper Insulation

scholarly journals Effect of TiO2 and ZnO Nanoparticles on the Performance of Dielectric Nanofluids Based on Vegetable Esters During Their Aging

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 692
Author(s):  
Inmaculada Fernández ◽  
Rafael Valiente ◽  
Félix Ortiz ◽  
Carlos J. Renedo ◽  
Alfredo Ortiz
Keyword(s):  
Breakdown Voltage ◽  
Vegetable Oil ◽  
Thermal Aging ◽  
Heat Dissipation ◽  
Dissipation Factor ◽  
Dielectric Behavior ◽  
Degree Of Polymerization ◽  
Point Of View ◽  
Transformer Oils ◽  
Natural Ester

Over the last few decades the insulating performance of transformer oils has been broadly studied under the point of view of nanotechnology, which tries to improve the insulating and heat dissipation performance of transformer oils by suspending nanoparticles. Many authors have analyzed the thermal and dielectric behavior of vegetable oil based-nanofluids, however, very few works have studied the evolution of these liquids during thermal aging and their stability. In this paper has been evaluated the performance of aged vegetable oil based-nanofluids, which have been subjected to accelerated thermal aging at 150 °C. Nanoparticles of TiO2 and ZnO have been dispersed in a commercial natural ester. Breakdown voltage, resistivity, dissipation factor and acidity of nanofluid samples have been measured according to standard methods, as well as stability. Moreover, it has been analyzed the degradation of Kraft paper through the degree of polymerization (DP). The results have showed that although nanoparticles improve breakdown voltage, they increase the ageing of insulation liquids and dielectric paper.

scholarly journals Hybrid Composites Based on Polypropylene with Basalt/Hazelnut Shell Fillers: The Influence of Temperature, Thermal Aging, and Water Absorption on Mechanical Properties

Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 18 ◽  
Author(s):  
Anna Kufel ◽  
Stanisław Kuciel
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Water Absorption ◽  
Thermal Aging ◽  
Hybrid Composites ◽  
Coefficient Of Thermal Expansion ◽  
Tensile Modulus ◽  
Charpy Impact ◽  
Creep Tests ◽  
Influence Of Temperature

The aim of the research was to study the effects of adding natural fillers to a polypropylene (PP) matrix on mechanical and physical properties of hybrid composites. The 10%, 15%, and 20% by weight basalt fibers (BF) and ground hazelnut shells (HS) were added to the PP matrix. Composites were produced by making use of an injection molding method. Tensile strength, tensile modulus, strain at break, Charpy impact strength, and the coefficient of thermal expansion were determined. The influence of temperature, thermal aging, and water absorption on mechanical properties was also investigated. In addition, short-time creep tests were carried out. To characterize the morphology and the filler distribution within the matrix, a scanning electron microscope (SEM) was used. The results showed that the addition of the two types of filler enhanced mechanical properties. Furthermore, improvements in thermal stability were monitored. After water absorption, the changes in the tensile properties of the tested composites were moderate. However, thermal aging caused a decrease in tensile strength and tensile modulus.

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