不同油流速度下油纸绝缘的局部放电特性研究
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摘要
目前随着变压器容量的增大,大部分变压器采用增加流速的方式来加快散热,但是流速的增大对油纸绝缘局部放电也会造成一定影响。为此,本文搭建了油纸绝缘系统的局部放电实验平台,研究流速对油纸绝缘局部放电特性的影响机制。研究结果表明,通过对油流静止下的放电图谱和实验现象分析,将油纸绝缘局部放电的过程划分为5个阶段:起始、缓慢发展、过渡、快速发展和预击穿阶段,并发现从过渡阶段到快速发展阶段存在一个转折电压,标志局部放电发展到绝缘纸板内部。在此基础上开展了不同流速下的局部放电试验,发现油纸绝缘局部放电参数随油流速度呈先减小后增大的趋势,在放电初期,不同流速间对于放电的影响较小,随着放电发展阶段的增加,流速间放电的差异逐渐明显。通过分析发现,电场强度和流速之间存在弱耦合关系,油纸绝缘局部放电水平的提升是电场强度和流速共同作用的结果,其结果导致放电后期的放电参数较前期更易受流速的影响。
At present with the increase of transformer capacity, most transformers speed up heat dissipation by increasing the oil flow rate, but which will also have a certain impact on partial discharge of oil-paper insulation. To study the influence mechanism of flow rate on partial discharge characteristics of oil-paper insulation, a partial discharge experimental platform is set up. The results show that the process of partial discharge of oil-paper insulation can be divided into five stages: initial phase, slow development, transition, rapid development, and pre-breakdown stage through the analysis of discharge patterns and experimental phenomena of static oil flow. From the stagnation stage to the rapid development stage, there is a turning voltage, which indicates that the partial discharge develops into the interior of the insulation board. On this basis, partial discharge tests at different flow rates are carried out, and it is found that the partial discharge parameters of oil-paper insulation first decrease and then go up with the increasing oil flow rate. In the early stage of discharge, the influence of different flow rates on the discharge is slight. With the progress of the discharge development stage, the difference between the flow rates is gradually obvious. By analyzing, there is a weak coupling between the electric field intensity and flow rate, which is the reason of the increase of the partial discharge level. Besides, the discharge parameters at the later stage are more affected by the flow rate than the previous period.
At present with the increase of transformer capacity, most transformers speed up heat dissipation by increasing the oil flow rate, but which will also have a certain impact on partial discharge of oil-paper insulation. To study the influence mechanism of flow rate on partial discharge characteristics of oil-paper insulation, a partial discharge experimental platform is set up. The results show that the process of partial discharge of oil-paper insulation can be divided into five stages: initial phase, slow development, transition, rapid development, and pre-breakdown stage through the analysis of discharge patterns and experimental phenomena of static oil flow. From the stagnation stage to the rapid development stage, there is a turning voltage, which indicates that the partial discharge develops into the interior of the insulation board. On this basis, partial discharge tests at different flow rates are carried out, and it is found that the partial discharge parameters of oil-paper insulation first decrease and then go up with the increasing oil flow rate. In the early stage of discharge, the influence of different flow rates on the discharge is slight. With the progress of the discharge development stage, the difference between the flow rates is gradually obvious. By analyzing, there is a weak coupling between the electric field intensity and flow rate, which is the reason of the increase of the partial discharge level. Besides, the discharge parameters at the later stage are more affected by the flow rate than the previous period.
引文
[1] 池明赫(Chi Minghe).运行条件对复合电场下油纸绝缘击穿特性的影响(Effect of operating conditions on dielectric breakdown characteristics of oil-paper under composite electric field)[D].哈尔滨:哈尔滨理工大学(Harbin:Harbin University of Science and Technology),2015.
[2] Wechsler K,Riccitiello M.Electric breakdown of a parallel solid and liquid dielectric system[J].Transactions of the American Institute of Electrical Engineers,1961,80(3):365-368.
[3] 周远翔,李光范,黄猛(Zhou Yuanxiang,Li Guangfan,Huang Meng).交直流复合电场中直流电压分量对油纸绝缘沿面放电过程的影响(The influence of DC voltage component on the surface discharge process of oil-paper insulation in AC DC composite electric field)[J].高电压技术(High Voltage Engineering),2015,41(9):3082-3090.
[4] Dai J,Wang Z D,Jarman P.Creepage discharge on insulation barriers in aged power transformers[J].IEEE Transactions on Dielectrics & Electrical Insulation,2010,17(4):1327-1335.
[5] Dai J,Wang Z D,Jarman P.Moisture and aging effect on the creepage discharge characteristics at the oil/transformer-board interface under divergent field[A].2008 Annual Report Conference on Electrical Insulation and Dielectric Phenomena[C].2008.662-665.
[6] 王伟(Wang Wei).老化与水分对油纸绝缘沿面爬电的影响(Effects of aging and moisture on the surface climbing of oil-paper insulation)[D].北京:华北电力大学(Beijing:North China Electric Power University),2012.
[7] 王辉,李成榕,贺惠民(Wang Hui,Li Chengrong,He Huimin).温度对油纸绝缘沿面放电发展过程的影响(Influence of temperature on the development process of surface discharge of oil-paper insulation[J].高电压技术(High Voltage Engineering),2010,36(4):884-890.
[8] 陈小龙(Chen Xiaolong).复合电场下换流变压器典型绝缘结构油流带电试验研究(Study on the oil-current charged test of typical insulation structure of converter transformer under composite electric field)[D].哈尔滨:哈尔滨理工大学(Harbin:Harbin University of Science and Technology),2013.
[9] Li S,Gao B,Wu G.Influences of oil flow speed and temperature on partial discharge properties in transformer oil[A].2016 Australasian Universities Power Engineering Conference (AUPEC) [C].2016.1-4.
[10] 刘知远(Liu Zhiyuan).流动状态下绝缘油中气泡放电特性及影响因素研究(Study on bubble discharge characteristics and influencing factors of insulating oil under flowing condition)[D].重庆:重庆大学(Chongqing:Chongqing University),2016.
[11] Gavis J,Koszman I.Development of charge in low conductivity liquids flowing past surfaces:A theory of the phenomenon in tubes[J].Journal of Colloid Science,1961,16(4):375-391.
[12] Morin A J,Zahn M,Melcher J R.Fluid electrification measurements of transformer pressboard/oil insulation in a Couette charger[J].IEEE Transactions on Electrical Insulation,1991,26(5):870-901.
[13] 陈庆国,高源,池明赫(Chen Qingguo,Gao Yuan,Chi Minghe).直流电场下典型油纸绝缘结构油流带电特性(Study on oil flow characteristics of typical oil-paper insulation structures under DC electric field)[J].高电压技术(High Voltage Engineering),2014,40(4):995-1001.
[14] 陈庆国,林林,高源(Chen Qingguo,Lin Lin,Gao Yuan).换流变压器中典型平板油纸绝缘结构的油流带电特性(Characteristics of oil flow in a typical flat oil-paper insulation structure in converter transformer)[J].电机与控制学报(Electric Machines & Control),2015,19(2):14-19.
[15] 张明君(Zhang Mingjun).流速对绝缘油中金属微粒放电的影响机制(Effect of flow rate on discharge of metal particles in insulating oil)[D].重庆:重庆大学(Chongqing:Chongqing University),2016.
[16] 李军浩,司文荣,姚秀(Li Junhao,Si Wenrong,Yao Xiu).油/纸绝缘沿面局部放电特性研究(Partial discharge characteristics of oil/paper insulation surface)[J].西安交通大学学报(Journal of Xi’an Jiaotong University),2009,43(6):108-112.
[17] 薛阳(Xue Yang).油纸绝缘沿面放电的发展过程及其严重程度的表征(Characterization of development and severity of creeping discharge of oil-paper insulation)[D].北京:华北电力大学(Beijing:North China Electric Power University),2011.
[18] 金福宝,周远翔,黄建文(Jin Fubao,Zhou Yuanxiang,Huang Jianwen).温度对交直流复合电场下油纸绝缘沿面放电特性的影响(Effects of temperature on the surface discharge characteristics of oil-paper insulation under AC-DC hybrid electric field)[J].高电压技术(High Voltage Engineering),2017,43(3):931-939.
[19] 谢军(Xie Jun).变压器油纸绝缘局部放电劣化规律及诊断方法(Partial discharge deterioration law and diagnostic method of transformer oil-paper insulation)[D].北京:华北电力大学(Beijing:North China Electric Power University),2016.
[20] 李清泉,李斯盟,司雯(Li Qingquan,Li Simeng,Si Wen).基于局部放电的电力变压器油纸绝缘状态评估关键问题分析(Analysis of key problems in oil-paper insulation state assessment of power transformers based on partial discharge)[J].高电压技术(High Voltage Engineering),2017,43(8):2558-2565.
[21] 涂愈明(Tu Yuming).超高压变压器油流静电带电的计算模型及实验研究(Calculation model and experimental study of electrostatic charging of ultra-high voltage transformer oil flow)[D].北京:清华大学(Beijing:Tsinghua University),1998.
[22] 陈庆国,董振鹏,林林(Chen Qingguo,Dong Zhenpeng,Lin Lin).温度对交直流叠加电场下油纸绝缘油流带电的影响(Influence of temperature on the charging of oil-paper insulated oil flow under AC and DC superimposed electric field) [J].电机与控制学报(Electric Machines & Control),2018,22(5):35-41.
[23] 周远翔,周仲柳,沙彦超,等(Zhou Yuanxiang,Zhou Zhongliu,Sha Yanchao,et al.).交直流复合电压下油纸绝缘典型缺陷局部放电发展阶段评估(Assessment of stages of partial discharge process of typical oil-paper insulation defect under combined AC-DC voltage)[J].电工电能新技术(Advanced Technology of Electrical Engineering and Energy),2018,37(6):50-57.
[24] 李康,郭润睿,Hassan Javed,等 (Li Kang,Guo Runrui,Hassan Javed,et al.).空气局部放电衍生物气体生成规律的研究(Study of air by-products formation characteristics under corona discharge)[J].电工电能新技术(Advanced Technology of Electrical Engineering and Energy),2017,36(8):1-7.
[25] 周远翔,黄欣,黄猛,等(Zhou Yuanxiang,Huang Xin,Huang Meng,et al.).温度对油纸绝缘空间电荷消散特性的影响(Influences of temperature on space charge dissipation in oil-paper insulation)[J].电工电能新技术(Advanced Technology of Electrical Engineering and Energy),2018,37(7):1-8.
[2] Wechsler K,Riccitiello M.Electric breakdown of a parallel solid and liquid dielectric system[J].Transactions of the American Institute of Electrical Engineers,1961,80(3):365-368.
[3] 周远翔,李光范,黄猛(Zhou Yuanxiang,Li Guangfan,Huang Meng).交直流复合电场中直流电压分量对油纸绝缘沿面放电过程的影响(The influence of DC voltage component on the surface discharge process of oil-paper insulation in AC DC composite electric field)[J].高电压技术(High Voltage Engineering),2015,41(9):3082-3090.
[4] Dai J,Wang Z D,Jarman P.Creepage discharge on insulation barriers in aged power transformers[J].IEEE Transactions on Dielectrics & Electrical Insulation,2010,17(4):1327-1335.
[5] Dai J,Wang Z D,Jarman P.Moisture and aging effect on the creepage discharge characteristics at the oil/transformer-board interface under divergent field[A].2008 Annual Report Conference on Electrical Insulation and Dielectric Phenomena[C].2008.662-665.
[6] 王伟(Wang Wei).老化与水分对油纸绝缘沿面爬电的影响(Effects of aging and moisture on the surface climbing of oil-paper insulation)[D].北京:华北电力大学(Beijing:North China Electric Power University),2012.
[7] 王辉,李成榕,贺惠民(Wang Hui,Li Chengrong,He Huimin).温度对油纸绝缘沿面放电发展过程的影响(Influence of temperature on the development process of surface discharge of oil-paper insulation[J].高电压技术(High Voltage Engineering),2010,36(4):884-890.
[8] 陈小龙(Chen Xiaolong).复合电场下换流变压器典型绝缘结构油流带电试验研究(Study on the oil-current charged test of typical insulation structure of converter transformer under composite electric field)[D].哈尔滨:哈尔滨理工大学(Harbin:Harbin University of Science and Technology),2013.
[9] Li S,Gao B,Wu G.Influences of oil flow speed and temperature on partial discharge properties in transformer oil[A].2016 Australasian Universities Power Engineering Conference (AUPEC) [C].2016.1-4.
[10] 刘知远(Liu Zhiyuan).流动状态下绝缘油中气泡放电特性及影响因素研究(Study on bubble discharge characteristics and influencing factors of insulating oil under flowing condition)[D].重庆:重庆大学(Chongqing:Chongqing University),2016.
[11] Gavis J,Koszman I.Development of charge in low conductivity liquids flowing past surfaces:A theory of the phenomenon in tubes[J].Journal of Colloid Science,1961,16(4):375-391.
[12] Morin A J,Zahn M,Melcher J R.Fluid electrification measurements of transformer pressboard/oil insulation in a Couette charger[J].IEEE Transactions on Electrical Insulation,1991,26(5):870-901.
[13] 陈庆国,高源,池明赫(Chen Qingguo,Gao Yuan,Chi Minghe).直流电场下典型油纸绝缘结构油流带电特性(Study on oil flow characteristics of typical oil-paper insulation structures under DC electric field)[J].高电压技术(High Voltage Engineering),2014,40(4):995-1001.
[14] 陈庆国,林林,高源(Chen Qingguo,Lin Lin,Gao Yuan).换流变压器中典型平板油纸绝缘结构的油流带电特性(Characteristics of oil flow in a typical flat oil-paper insulation structure in converter transformer)[J].电机与控制学报(Electric Machines & Control),2015,19(2):14-19.
[15] 张明君(Zhang Mingjun).流速对绝缘油中金属微粒放电的影响机制(Effect of flow rate on discharge of metal particles in insulating oil)[D].重庆:重庆大学(Chongqing:Chongqing University),2016.
[16] 李军浩,司文荣,姚秀(Li Junhao,Si Wenrong,Yao Xiu).油/纸绝缘沿面局部放电特性研究(Partial discharge characteristics of oil/paper insulation surface)[J].西安交通大学学报(Journal of Xi’an Jiaotong University),2009,43(6):108-112.
[17] 薛阳(Xue Yang).油纸绝缘沿面放电的发展过程及其严重程度的表征(Characterization of development and severity of creeping discharge of oil-paper insulation)[D].北京:华北电力大学(Beijing:North China Electric Power University),2011.
[18] 金福宝,周远翔,黄建文(Jin Fubao,Zhou Yuanxiang,Huang Jianwen).温度对交直流复合电场下油纸绝缘沿面放电特性的影响(Effects of temperature on the surface discharge characteristics of oil-paper insulation under AC-DC hybrid electric field)[J].高电压技术(High Voltage Engineering),2017,43(3):931-939.
[19] 谢军(Xie Jun).变压器油纸绝缘局部放电劣化规律及诊断方法(Partial discharge deterioration law and diagnostic method of transformer oil-paper insulation)[D].北京:华北电力大学(Beijing:North China Electric Power University),2016.
[20] 李清泉,李斯盟,司雯(Li Qingquan,Li Simeng,Si Wen).基于局部放电的电力变压器油纸绝缘状态评估关键问题分析(Analysis of key problems in oil-paper insulation state assessment of power transformers based on partial discharge)[J].高电压技术(High Voltage Engineering),2017,43(8):2558-2565.
[21] 涂愈明(Tu Yuming).超高压变压器油流静电带电的计算模型及实验研究(Calculation model and experimental study of electrostatic charging of ultra-high voltage transformer oil flow)[D].北京:清华大学(Beijing:Tsinghua University),1998.
[22] 陈庆国,董振鹏,林林(Chen Qingguo,Dong Zhenpeng,Lin Lin).温度对交直流叠加电场下油纸绝缘油流带电的影响(Influence of temperature on the charging of oil-paper insulated oil flow under AC and DC superimposed electric field) [J].电机与控制学报(Electric Machines & Control),2018,22(5):35-41.
[23] 周远翔,周仲柳,沙彦超,等(Zhou Yuanxiang,Zhou Zhongliu,Sha Yanchao,et al.).交直流复合电压下油纸绝缘典型缺陷局部放电发展阶段评估(Assessment of stages of partial discharge process of typical oil-paper insulation defect under combined AC-DC voltage)[J].电工电能新技术(Advanced Technology of Electrical Engineering and Energy),2018,37(6):50-57.
[24] 李康,郭润睿,Hassan Javed,等 (Li Kang,Guo Runrui,Hassan Javed,et al.).空气局部放电衍生物气体生成规律的研究(Study of air by-products formation characteristics under corona discharge)[J].电工电能新技术(Advanced Technology of Electrical Engineering and Energy),2017,36(8):1-7.
[25] 周远翔,黄欣,黄猛,等(Zhou Yuanxiang,Huang Xin,Huang Meng,et al.).温度对油纸绝缘空间电荷消散特性的影响(Influences of temperature on space charge dissipation in oil-paper insulation)[J].电工电能新技术(Advanced Technology of Electrical Engineering and Energy),2018,37(7):1-8.