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Jian Li - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of trimethylolpropane fatty acid triester as a high performance electrical Insulating Oil
Industrial Crops and Products, 2019Co-Authors: Kaizheng Wang, Jian Li, Feipeng Wang, Qi Zhao, Zhengyong Huang, Kelin HuAbstract:Abstract The trimethylolpropane esters (TME) based high performance electrical Insulating Oil was synthesized by esterification of the mixture of C6, C8 and C10 acids blend with trimethylolpropane (TMP). The conversion yields of TME is maximized at catalyst (SnCl2) dosage of 0.8 wt.% and the TMP:acid molar ratio of 3.2:1 at 140 °C. The electrical performance is significantly improved by a purpose-oriented purification process which is structured by washing with ultrapure water and absorption with molecular sieve. The obtained Insulating Oil shows much reduced viscosity (23.3 mm2 s−1) and much enhanced AC breakdown voltage (72.6 kV) comparing with the commercial natural ester Insulating Oil FR3® (34 mm2s−1 and 63 kV). The high performance of the Insulating Oil is also manifested by quite low pour point (−45 °C) and high flash point (248 °C) which are superior to those values of mineral Insulating Oil (−30 °C and 170 °C). The remarkable oxidation stability of the Insulating Oil is metered by the oxidation induction time (OIT) 2275 min at 130 °C which should be attributed to the elimination of C C double bonds and β-H atoms.
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Synthesis of Trimethylolpropane Esters as Potential Insulating Oil Base Stocks
2019 IEEE 20th International Conference on Dielectric Liquids (ICDL), 2019Co-Authors: Feipeng Wang, Jian Li, Kaizheng Wang, Qi Zhao, Kelin HuAbstract:The trimethylolpropane esters (TME) based high performance electrical Insulating Oil was synthesized by esterification of the mixture of C6, C8 and C10 acids blend with trimethylolpropane (TMP). The electrical performance is significantly improved by a purpose-oriented purification process which is structured by washing with ultrapure water and absorption with molecular sieve. The obtained Insulating Oil shows much reduced viscosity (25.6 mm2/s) and much enhanced AC breakdown voltage (72.6 kV) comparing with the commercial natural ester Insulating Oil FR3® (38.9 mm2/s and 65 kV). The high performance of the Insulating Oil is also manifested by quite low pour point (-45oC) and relative high flash point (240oC). The remarkable oxidation stability of the Insulating Oil is metered by the oxidation induction temperature (OIT) 203oC which should be attributed to the elimination of C=C double bonds and β-H atoms.
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Synthesis of Trimethylolpropane Esters as Potential Insulating Oil Base Stocks
2019 IEEE 20th International Conference on Dielectric Liquids (ICDL), 2019Co-Authors: Feipeng Wang, Jian Li, Kaizheng Wang, Qi Zhao, Kelin HuAbstract:The trimethylolpropane esters (TME) based high performance electrical Insulating Oil was synthesized by esterification of the mixture of C 6 , C 8 and C 10 acids blend with trimethylolpropane (TMP). The electrical performance is significantly improved by a purpose-oriented purification process which is structured by washing with ultrapure water and absorption with molecular sieve. The obtained Insulating Oil shows much reduced viscosity (25.6 mm2/s) and much enhanced AC breakdown voltage (72.6 kV) comparing with the commercial natural ester Insulating FR3® (38.9 mm2/s and 65 kV). The high performance of the Insulating Oil is also manifested by quite low pour point (-45°C) and relative high flash point (240°C). The remarkable oxidation stability of the Insulating Oil is metered by the oxidation induction temperature (OIT) 203°C which should be attributed to the elimination of C=C double bonds and $\beta$-H atoms.
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Analysis of Dielectric Properties and Breakdown Characteristics of Vegetable Insulating Oil with Modified by ZnO Nanoparticles
2018 IEEE International Conference on High Voltage Engineering and Application (ICHVE), 2018Co-Authors: Gang Chen, Jian Li, Qiang Wang, Zhengyong Huang, Hua Yin, Lin Liu, Jianxin Sun, Jianfeng HeAbstract:In view of the higher requirements of electrical, physical and chemical properties of vegetable Insulating Oil in large power transformers, the method of improving insulation characteristics of vegetable Insulating Oil by using nanoparticles has become a research hotspot at home and abroad. In this paper, the preparation, surface modification of ZnO nanoparticles and the preparation process of the vegetable Insulating Oil based ZnO nanofluids (NF) were studied. The effects of different ZnO nanoparticles concentration on dielectric properties and breakdown characteristics of vegetable Insulating Oil were analyzed. The results shown that the power frequency breakdown voltage of ZnO NF similar to linear increased with the increasing of nanoparticles concentration, the maximum increase was 30.17%. The positive and negative polarity breakdown voltage of lightning impulse shown a trend of first rise and then decrease, and the positive and negative breakdown voltage increased by 24.62% and 5.46%, respectively. Both the positive and negative lightning impulse breakdown time of ZnO NF increasing with the nanoparticles concentration, the max value were 18.94%, 35.76%, respectively. However, ZnO nanoparticles would increase the dielectric loss of vegetable Insulating Oil and reduce its volume resistivity.
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Study on the Analysis and Diagnosis of Dissolved Gases in Camellia Insulating Oil
2018 IEEE International Conference on High Voltage Engineering and Application (ICHVE), 2018Co-Authors: Hanxiang Wang, Jian Li, Feipeng Wang, Chenmeng Xiang, Zhengyong Huang, Sijing HeAbstract:Recently, as a kind of transformer Oil with lots of outstanding characteristics such as high ignition point, reproducible, and natural degradation, vegetable Insulating Oil has becomes more and more popular in the Oil-filled transformers. Thermal ageing as well as thermal and electrical faults, which can lead to the decomposition of Insulating Oil and Insulating paper, will occur in operating transformers, then dissolved gases are formed and reach equilibrium in Oil through diffusion process. In this paper, camellia Oil as sample Oil, thermal ageing as well as thermal and electrical faults simulation experiments of transformers were conducted, main characteristic gases decomposed by camellia Insulating Oil were obtained, and the changing rules of gas content with the changing of thermal ageing time, thermal fault temperature and discharge energy were also analyzed. Which indicated that if we increase the thermal ageing time, thermal faults temperature and discharge energy, the decomposition processes of camellia Insulating Oil could also be accelerated. And also the decomposition processes of camellia Insulating Oil and insulation paper under thermal and electrical stress were analyzed. Simulation results explained the gas production rules of thermal ageing and thermal faults as well as electrical faults of camellia Insulating Oil at microcosmic level. The result of above study provides theoretic support for condition assessment and operating maintenance of vegetable Insulating Oil-filled transformers, and also has great theoretical reference value and practical guiding significance for ensuring safe operation of vegetable Insulating Oil-filled transformers.
Feipeng Wang - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of trimethylolpropane fatty acid triester as a high performance electrical Insulating Oil
Industrial Crops and Products, 2019Co-Authors: Kaizheng Wang, Jian Li, Feipeng Wang, Qi Zhao, Zhengyong Huang, Kelin HuAbstract:Abstract The trimethylolpropane esters (TME) based high performance electrical Insulating Oil was synthesized by esterification of the mixture of C6, C8 and C10 acids blend with trimethylolpropane (TMP). The conversion yields of TME is maximized at catalyst (SnCl2) dosage of 0.8 wt.% and the TMP:acid molar ratio of 3.2:1 at 140 °C. The electrical performance is significantly improved by a purpose-oriented purification process which is structured by washing with ultrapure water and absorption with molecular sieve. The obtained Insulating Oil shows much reduced viscosity (23.3 mm2 s−1) and much enhanced AC breakdown voltage (72.6 kV) comparing with the commercial natural ester Insulating Oil FR3® (34 mm2s−1 and 63 kV). The high performance of the Insulating Oil is also manifested by quite low pour point (−45 °C) and high flash point (248 °C) which are superior to those values of mineral Insulating Oil (−30 °C and 170 °C). The remarkable oxidation stability of the Insulating Oil is metered by the oxidation induction time (OIT) 2275 min at 130 °C which should be attributed to the elimination of C C double bonds and β-H atoms.
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Synthesis of Trimethylolpropane Esters as Potential Insulating Oil Base Stocks
2019 IEEE 20th International Conference on Dielectric Liquids (ICDL), 2019Co-Authors: Feipeng Wang, Jian Li, Kaizheng Wang, Qi Zhao, Kelin HuAbstract:The trimethylolpropane esters (TME) based high performance electrical Insulating Oil was synthesized by esterification of the mixture of C6, C8 and C10 acids blend with trimethylolpropane (TMP). The electrical performance is significantly improved by a purpose-oriented purification process which is structured by washing with ultrapure water and absorption with molecular sieve. The obtained Insulating Oil shows much reduced viscosity (25.6 mm2/s) and much enhanced AC breakdown voltage (72.6 kV) comparing with the commercial natural ester Insulating Oil FR3® (38.9 mm2/s and 65 kV). The high performance of the Insulating Oil is also manifested by quite low pour point (-45oC) and relative high flash point (240oC). The remarkable oxidation stability of the Insulating Oil is metered by the oxidation induction temperature (OIT) 203oC which should be attributed to the elimination of C=C double bonds and β-H atoms.
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Synthesis of Trimethylolpropane Esters as Potential Insulating Oil Base Stocks
2019 IEEE 20th International Conference on Dielectric Liquids (ICDL), 2019Co-Authors: Feipeng Wang, Jian Li, Kaizheng Wang, Qi Zhao, Kelin HuAbstract:The trimethylolpropane esters (TME) based high performance electrical Insulating Oil was synthesized by esterification of the mixture of C 6 , C 8 and C 10 acids blend with trimethylolpropane (TMP). The electrical performance is significantly improved by a purpose-oriented purification process which is structured by washing with ultrapure water and absorption with molecular sieve. The obtained Insulating Oil shows much reduced viscosity (25.6 mm2/s) and much enhanced AC breakdown voltage (72.6 kV) comparing with the commercial natural ester Insulating FR3® (38.9 mm2/s and 65 kV). The high performance of the Insulating Oil is also manifested by quite low pour point (-45°C) and relative high flash point (240°C). The remarkable oxidation stability of the Insulating Oil is metered by the oxidation induction temperature (OIT) 203°C which should be attributed to the elimination of C=C double bonds and $\beta$-H atoms.
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Dissolved Gas Analysis in Camellia Insulating Oil during Thermal Ageing Test
2019 2nd International Conference on Electrical Materials and Power Equipment (ICEMPE), 2019Co-Authors: Lingyun Gu, Feipeng Wang, Kaizheng Wang, Chenmeng Xiang, Qiuhuang Han, Changkai Shi, Yan Wu, Xuefeng BaiAbstract:Vegetable Insulating Oil, one of the environmental friendly dielectric liquids, has been widely utilized with Oil-filled transformers during the past two decades. As like mineral-Oil filled transformers, thermal ageing is also critical for evaluating the performance of vegetable-Oil filled transformers. The detection of the dissolved gases and clarification of the gas production regularity are necessary for understanding the thermal aging mechanism of vegetable Insulating Oils. In this work, experiments were conducted to simulate the thermal ageing process of camellia Insulating Oil, and to find out the composition variation regularities of characteristic dissolved gases by various thermal ageing temperature and duration. The results shown that CO and CO2, but also H2 and C2H6 were the main characteristic gases produced during the thermal ageing of camellia Insulating Oil, meanwhile the percentage composition of C2H6 tended to increase with the increased thermal ageing duration, while H2 showed an opposite tendency. The acid value variation of the Oils recorded during the test tended to be increased with extended thermal aging durations.
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Biodegradation performance of environmentally-friendly Insulating Oil
IOP Conference Series: Earth and Environmental Science, 2018Co-Authors: Jun Yang, Yan He, Cheng Chen, Feipeng Wang, Liya WuAbstract:In this paper, biodegradation performance of rapeseed Insulating Oil (RDB) and FR3 Insulating Oil (FR3) was studied by means of ready biodegradation method which was performed with Organization for Economic Co-operation and Development (OECD) 301B. For comparison, the biodegradation behaviour of 25# mineral Insulating Oil was also characterized with the same method. The testing results shown that the biodegradation degree of rapeseed Insulating Oil, FR3 Insulating Oil and 25# mineral Insulating Oil was 95.8%, 98.9% and 38.4% respectively. Following the "new chemical risk assessment guidelines" (HJ/T 154 - 2004), which illustrates the methods used to identify and assess the process safety hazards inherent. The guidelines can draw that the two vegetable Insulating Oils, i.e. rapeseed Insulating Oil and FR3 Insulating Oil are easily biodegradable. Therefore, the both can be classified as environmentally-friendly Insulating Oil. As expected, 25# mineral Insulating Oil is hardly biodegradable. The main reason is that 25# mineral Insulating Oil consists of isoalkanes, cyclanes and a few arenes, which has few unsaturated bonds. Biodegradation of rapeseed Insulating Oil and FR3 Insulating Oil also remain some difference. Biodegradation mechanism of vegetable Insulating Oil was revealed from the perspective of hydrolysis kinetics.
Tsuyoshi Amimoto - One of the best experts on this subject based on the ideXlab platform.
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Mechanism of Increase of Electrostatic Charging Tendency in Insulating Oil for Oil-immersed Transformer
Ieej Transactions on Power and Energy, 2020Co-Authors: Sigemitsu Okabe, Masanori Kotoh, Motoo Tsuchie, Tsuyoshi AmimotoAbstract:Both of the mechanism and the causing compound to increase the electrostatic charging tendency (ECT) of Insulating Oil was investigated by accelerated deterioration tests with the addition of various compounds. Although the ECT of the Insulating Oil was almost constant when only sulfoxide compounds were added, remarkable increase was observed when either of hydrochloric acid or moisture, which was considered to be generated by the aging of Insulating Oil, was further added to the Oil containing sulfoxide compounds. It is presumed that sulfonium ion, which is generated by the reaction between sulfoxide compound and hydrogen ion, is the compound to directly contribute the increase in ECT. Hydrogen ion can be supplied from the organic acids, which is generated by the oxidation of hydrocarbon in aging Insulating Oil. It is considered that the increase in ECT of Insulating Oil is caused by the generation of sulfoxide by the oxidation of sulfide, which is contained in new Oil (origin compound), and the generation of sulfonium ion from the reaction between sulfoxide and hydrogen ion, which is generated due to aging.
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Method to evaluate the degradation condition of transformer Insulating Oil - establishment of the evaluation method and application to field transformer Oil
IEEE Transactions on Dielectrics and Electrical Insulation, 2015Co-Authors: Junichi Wada, Shigemitsu Okabe, Genyo Ueta, Tsuyoshi AmimotoAbstract:To operate power transformers long-term, as well as ensuring their Insulating reliability, it is important to study age-related decline in various Insulating Oil characteristics and the method used to evaluate the same adequately. Previous studies showed that age-related decline in Insulating Oil characteristics was caused by trace components in Oil produced during oxidation degradation. To maintain and manage aged Insulating Oil rationally, a specific diagnostic method must be studied, based on measurement of the trace components in Oil that cause degradation in these Insulating Oil characteristics. The present study evaluated the sensitivity to detect various components based on the amount of trace components produced in Oil during oxidation degradation for field-aged Insulating Oil for 34 transformers in various degradation conditions. A study was also conducted to evaluate the degradation condition based on the ratio of trace components produced in Oil. Consequently, the detection sensitivity levels were in the order of carbonyl value, saponification value, peroxide value, and total acid value. As the ratio of the saponification value - the so-called final product - increased, the degradation of Insulating Oil developed further. With the above study results, methods of evaluating the dissociation property in the preceding study and the breakdown voltage with the degree of water saturation taken into consideration were combined to establish a comprehensive method of evaluating aged Oil. This was then applied to field-aged Insulating Oil as an example, whereupon the need to replace Insulating Oil could be evaluated.
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Techniques to inhibit transformer Insulating Oil degradation - Effectiveness evaluation of the removal of degradation products using adsorbents
IEEE Transactions on Dielectrics and Electrical Insulation, 2013Co-Authors: Junichi Wada, Shigemitsu Okabe, Genyo Ueta, Tsuyoshi AmimotoAbstract:For long-term operation of power transformers, as well as ensuring their Insulating reliability, an adequate study must be conducted on the age-related decline in various Insulating Oil characteristics and the method to inhibit the decline. In the present paper, to inhibit the degradation of Insulating Oil, a study was conducted on a method of removing the degradation products generated in Insulating Oil due to aging and the effect of removing these products. Consequently, for simulated degraded Oil subjected to heat stress of 10 years old, degraded through the accelerated degradation of new Oil, the performance of Insulating Oil subject to such accelerated degradation was improved through adsorption treatment and short-term improvement was able to be observed. Following reheating after the adsorbent treatment, a long-term improvement effect to prevent the decline in Insulating Oil characteristics due to degradation was able to also be observed. On the other hand, for the Insulating Oil aged about 30 years in the field, the effect was less than that for simulated degraded Oil equivalent to about 10 years old. The effect of the adsorbent was able to vary depending on the amount used and the degree of Insulating Oil degradation. Accordingly, volume resistivity, representing the degree of Insulating Oil degradation, was varied to study the effect of the adsorbent with respect to its amount. As a result, it emerged that, as the amount of adsorbent was increased, the inhibitory effect on degradation increased but the effect was less significant for Insulating Oil with volume resistivity significantly decreased. Based on these results, it was clarified that, for aged Oil with a low degree of degradation, an inhibitory effect on the short- and long-term decline in Insulating Oil characteristics was able to be obtained through adsorbent treatment.
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Influence of trace components contained in transformer Insulating Oil on various characteristics over time
IEEE Transactions on Dielectrics and Electrical Insulation, 2013Co-Authors: Junichi Wada, Shigemitsu Okabe, Genyo Ueta, Tsuyoshi AmimotoAbstract:To operate power transformers long-term, as well as ensuring their Insulating reliability, adequate consideration must also be paid to the age-related decline in various Insulating Oil characteristics. Previous studies could roughly clarify the key components causing the Insulating Oil characteristics to decline by adding the components contained in field transformer Insulating Oil to Oil with few impurities. On the other hand, this degradation causing components are trace components not present in the new Oil. To clarify the Insulating Oil degradation mechanism over time, the components determined as the sources of the degradation causing components (source components) must be investigated. Accordingly, in this paper, a study is conducted on the influence of the trace components present in new Oil on the degradation of the characteristics over time. In addition, since the breakdown characteristics of Insulating Oil are influenced by the water content in Oil, the influence of the combined effect of various components and water etc. is also studied. Consequently, it emerged that sulfide (octyl sulfide), or sulfur compounds detected in new Oil increased the copper content in Oil, showing a tendency toward an increasing dissipation factor and declining volume resistivity characteristics. Conversely, no influence of additives was observed on the increase in water content and the relationship between breakdown voltage and water content remained almost unchanged, regardless of the presence or absence of additives. Following the study of the change based on interaction with water content, no influence of the presence or absence of the additives was observed on the characteristics (acidity, interfacial tension, and breakdown voltage). Based on the above, it was clarified that, among the trace components existing in Oil used in the present experiment, octyl sulfide had impact on the Insulating Oil characteristics over time.
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Mechanism of increase of electrostatic charging tendency in Insulating Oil for Oil-immersed transformer
Electrical Engineering in Japan, 2011Co-Authors: Sigemitsu Okabe, Masanori Kotoh, Motoo Tsuchie, Tsuyoshi AmimotoAbstract:The mechanism of the increase in the electrostatic charging tendency (ECT) of Insulating Oil and causative compounds were investigated by accelerated deterioration tests with the addition of various compounds. Although the ECT of the Insulating Oil was almost constant when only sulfoxide compounds were added, a marked increase was observed when either hydrochloric acid or moisture, which was considered to be generated by the aging of Insulating Oil, was also added to Oil containing sulfoxide compounds. It is assumed that the sulfonium ion, which is generated by the reaction between sulfoxide compounds and hydrogen ion, is the compound that directly contributes to the increase in the ECT. Hydrogen ions can be supplied from organic acids generated by the oxidation of hydrocarbons in aging Insulating Oil. It is considered that the increase in the ECT of Insulating Oil is caused by the generation of sulfoxides by the oxidation of sulfide, which are present in fresh Oil (originating compounds), and the generation of sulfonium ions by a reaction between sulfoxide and hydrogen ions, which are formed during aging. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(4): 26–33, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21113
Kelin Hu - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of trimethylolpropane fatty acid triester as a high performance electrical Insulating Oil
Industrial Crops and Products, 2019Co-Authors: Kaizheng Wang, Jian Li, Feipeng Wang, Qi Zhao, Zhengyong Huang, Kelin HuAbstract:Abstract The trimethylolpropane esters (TME) based high performance electrical Insulating Oil was synthesized by esterification of the mixture of C6, C8 and C10 acids blend with trimethylolpropane (TMP). The conversion yields of TME is maximized at catalyst (SnCl2) dosage of 0.8 wt.% and the TMP:acid molar ratio of 3.2:1 at 140 °C. The electrical performance is significantly improved by a purpose-oriented purification process which is structured by washing with ultrapure water and absorption with molecular sieve. The obtained Insulating Oil shows much reduced viscosity (23.3 mm2 s−1) and much enhanced AC breakdown voltage (72.6 kV) comparing with the commercial natural ester Insulating Oil FR3® (34 mm2s−1 and 63 kV). The high performance of the Insulating Oil is also manifested by quite low pour point (−45 °C) and high flash point (248 °C) which are superior to those values of mineral Insulating Oil (−30 °C and 170 °C). The remarkable oxidation stability of the Insulating Oil is metered by the oxidation induction time (OIT) 2275 min at 130 °C which should be attributed to the elimination of C C double bonds and β-H atoms.
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Synthesis of Trimethylolpropane Esters as Potential Insulating Oil Base Stocks
2019 IEEE 20th International Conference on Dielectric Liquids (ICDL), 2019Co-Authors: Feipeng Wang, Jian Li, Kaizheng Wang, Qi Zhao, Kelin HuAbstract:The trimethylolpropane esters (TME) based high performance electrical Insulating Oil was synthesized by esterification of the mixture of C6, C8 and C10 acids blend with trimethylolpropane (TMP). The electrical performance is significantly improved by a purpose-oriented purification process which is structured by washing with ultrapure water and absorption with molecular sieve. The obtained Insulating Oil shows much reduced viscosity (25.6 mm2/s) and much enhanced AC breakdown voltage (72.6 kV) comparing with the commercial natural ester Insulating Oil FR3® (38.9 mm2/s and 65 kV). The high performance of the Insulating Oil is also manifested by quite low pour point (-45oC) and relative high flash point (240oC). The remarkable oxidation stability of the Insulating Oil is metered by the oxidation induction temperature (OIT) 203oC which should be attributed to the elimination of C=C double bonds and β-H atoms.
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Synthesis of Trimethylolpropane Esters as Potential Insulating Oil Base Stocks
2019 IEEE 20th International Conference on Dielectric Liquids (ICDL), 2019Co-Authors: Feipeng Wang, Jian Li, Kaizheng Wang, Qi Zhao, Kelin HuAbstract:The trimethylolpropane esters (TME) based high performance electrical Insulating Oil was synthesized by esterification of the mixture of C 6 , C 8 and C 10 acids blend with trimethylolpropane (TMP). The electrical performance is significantly improved by a purpose-oriented purification process which is structured by washing with ultrapure water and absorption with molecular sieve. The obtained Insulating Oil shows much reduced viscosity (25.6 mm2/s) and much enhanced AC breakdown voltage (72.6 kV) comparing with the commercial natural ester Insulating FR3® (38.9 mm2/s and 65 kV). The high performance of the Insulating Oil is also manifested by quite low pour point (-45°C) and relative high flash point (240°C). The remarkable oxidation stability of the Insulating Oil is metered by the oxidation induction temperature (OIT) 203°C which should be attributed to the elimination of C=C double bonds and $\beta$-H atoms.
Ruijin Liao - One of the best experts on this subject based on the ideXlab platform.
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The Effects of Insulating Oil Replacement Upon Power Transformer Condition Assessment
Electric Power Components and Systems, 2015Co-Authors: Ruijin LiaoAbstract:Abstract—Insulating Oil replacement is one of the most commonly used measures to solve Oil deterioration in field transformers. However, the effects of Oil replacement upon transformer condition assessment are still unknown. This article presents a simulated Oil replacement in the process of an accelerated thermal aging test. The accelerated thermal aging experiment was conducted at 130°C for 80 days; Insulating Oil was replaced on the 25th day of aging. Several common condition assessment methods, including degree of polymerization of the paper, Oil acidity, dielectric strength of the Oil–paper insulation, moisture estimation, and furfural analysis, were compared before and after Oil replacement. Results showed that Oil replacement is effective in solving the degradation of Insulating Oil but not in restraining the aging of paper. The variation of dielectric strength of insulation paper caused by Oil replacement could be neglected. Moisture estimation of insulation paper was closely related to the aging ...
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Characteristics of acid value in vegetable Insulating Oil during thermal aging
2014 ICHVE International Conference on High Voltage Engineering and Application, 2014Co-Authors: Zhengjiang Wang, Jian Li, Lijun Yang, Ruijin LiaoAbstract:Acid value is an important indicator used to evaluate the quality of Insulating Oil. The paper presents the characteristics of acid value in vegetable Insulating Oil during thermal aging. The individual experiments of hydrolysis and oxidation of vegetable Oil were conducted for furthermore analysis to the origin of acidic products in vegetable Oil. The quality requirement of acid value which is suitable for vegetable Oil was also proposed. The experimental results show that the acidic products in aged vegetable Oil mainly come from the hydrolysis of vegetable Oil. It is suggested that we must pay enough attention when the acidity of vegetable Insulating Oil reaches to 2.4 mg KOH/g, because it means the moisture accumulation in Insulating paper is already reach 2%.
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The compatibility tests between vegetable Insulating Oil and mineral Insulating Oil
2014 ICHVE International Conference on High Voltage Engineering and Application, 2014Co-Authors: Qingdan Huang, Baimei Wang, Jian Li, Lijun Yang, Ruijin LiaoAbstract:Vegetable Insulating Oil shows good performance in electric, high anti-aging ability and environmental protection. Thus it is considered as a promising substitute for mineral Insulating Oil. In order to the wide spread application of vegetable Oil in large power transformers, this paper designed the compatibility tests between vegetable Insulating Oil and mineral Insulating Oil. The changing rules of thermal aging characteristics in Insulating Oil influenced by different proportions were obtained. The changing rules of acid value, moisture content and breakdown voltages of mixed Oil influenced by different proportions were analyzed. Experimental results indicate that the molecular composition of Insulating Oil have a great influence on the physical, chemical and electrical properties of Oil. The more of vegetable Insulating Oil in mixed Insulating Oil, the higher acid value and moisture content of Oil is. Vegetable Insulating Oil and mineral Insulating Oil has good compatibility in thermal aging tests.
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Improvement on the anti-aging properties of power transformers by using mixed Insulating Oil
2010 International Conference on High Voltage Engineering and Application, 2010Co-Authors: Ruijin Liao, Lijun Yang, Shuaiwei LiangAbstract:This paper is aimed at improving the anti-aging properties of power transformers via using mineral Oil/natural ester mixtures (mixed Insulating Oil). Accelerated thermal aging of two kinds of Oil-paper insulation at 110°C were conducted in order to compare the aging characteristics of Kraft paper immersed in mixed Insulating Oil and mineral Oil. The extent of paper degradation after aging was determined using the paper degree of polymerization (DP). The dissipation factor of aged Oils and papers in two kinds of Oil-paper insulation, and the structure of papers immersed in mixed Insulating Oil and mineral Oil were also investigated. Paper immersed in mixed Insulating Oil degrades at a slower rate than in mineral Oil. Compared with mineral Oil/paper insulation, the transesterification of cellulose impregnated with mixed Insulating Oil can restrain the aging of paper. After aging 782 days, the dissipation factor of mixed Insulating Oil is nearly all smaller than mineral Oil from 10-1Hz to 106Hz, and the dissipation factor of paper aged in mixed Insulating Oil is smaller than paper aged in mineral Oil from 10-1Hz to 103Hz.