750kv输电线路绝缘子串电压分布的研究
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重庆大学 硕士学位论文 750kV输电线路绝缘子串电压分布研究 姓名：田金虎 申请学位级别：硕士 专业：电气工程 指导教师：刘渝根
2010-05
中文摘要
摘要
绝缘子是架空输电线路的关键部件之一，其性能的优劣直接影响到整条线路的安全 运行。由于绝缘子串与导线、铁塔及金具之间杂散电容的存在，使得沿绝缘子串的电压 分布不均匀。随着 750kV 电网建设在西北五省的全面展开，750kV 电网将成为我国西北 地区的主网架。750kV 输电线路采用的绝缘子串属于超长串、绝缘子型号及规格多样， 绝缘子串电压分布不均匀更加突出，均压措施实施复杂、困难。因 此 ， 确 定 绝 缘 子 串 电位分布，对检测低、零值绝缘子，确保输电线路的安全、稳定运行具有重要的 意义。750kV 交流超高压输电线路运行至今，还没有绝缘子串分布电压的标准，这不利 于对绝缘子串中劣化绝缘子的判别，影响线路的安全运行。
① 仿真计算时，分裂导线对绝缘子串电位分布计算影响明显，它能够使绝缘子串 电位分布更加均匀化；当分裂导线长度取为绝缘子串长的 8 倍以上时，与实际导线的效 果类似；考虑同一杆塔上的其他相导线的影响时绝缘子串电位分布更加不均匀。铁塔对 绝缘子串电位分布影响明显，忽略铁塔影响时绝缘子串电位分布会更加不均匀，特别是 对靠近接地端的绝缘子承受电压影响显著。避雷线、绝缘子伞形结构、绝缘子串的悬挂 方式、导线排列方式、绝缘子材质等因素对不同位置的绝缘子串电位分布的计算均有影 响。
③ Increasing the number of insulator could reduce the withstand voltage of single insulator. But that only make obvious effect for the insulators which near by the tower and not effect for the side of conductor. The potential distribution of insulator strings is more and more uneven when increase the number of insulator.
② 对 瓷 / 玻 璃 绝 缘 子 均 压 环 上 抗 位 置 在 2~3 片 绝 缘 子 处 ， 环 径 取 为 900mm~1000mm，环管径取为 100mm~120mm 绝缘子串电位、电场分布更为均匀；对 复合绝缘子均压环抬高距 h 取 150mm~300mm、环径 R 取 1100~1300mm、管径 Φ 取 140mm~180mm 时绝缘子各部分表面电场较ห้องสมุดไป่ตู้。
根据 750kV 输电线路线路实际情况，考虑铁塔、分裂导线、均压环、避雷线等因 素的影响，建立了 750kV 输电线路绝缘子串三维电场有限元计算模型，研究确定 750kV 绝缘子串电压分布规律。分析讨论了分裂导线、铁塔、避雷线、均压环、绝缘子型号、 绝缘子材质、悬挂方式、导线排列方式等因素对线路不同位置绝缘子串电位分布仿真计 算的影响，优化了均压环结构，进而确定了不同塔型、不同绝缘子片数、不同绝缘子型 号、不同材质绝缘子的 750kV 输电线路绝缘子串电位分布。主要得到了以下结论：
II
英文摘要
tower, the potential distribution of insulator string will be more uneven, especially take significant for the ground side of the insulator withstand voltage. Other factors such as shield line, the type of insulators, insulator suspension mode, the arrangement of conductors, material of insulators and so on, have influence on the potential distribution of insulator strings.
② The best parameter of grading ring to control the electric field distribution of insulators for porcelain or glass insulators is that the position of ring is located between the second and third insulator，and the diameter of grading ring is taken as 900mm~1000mm, and the caliber of grading ring taken to be 100mm~120mm. And the best for the composite insulators is that the value range of h is 150mm~300mm, 1100mm~1300mm for R and Φ is taken as 140mm~180mm.
① The bundle conductor make obvious effect for potential distribution of insulator strings. It can make the potential distribution of insulator string more uniform. The results show that if the length of conductor is more than 8 times of the length of insulator strings, the effect of conductor is equivalent with the actual wire. The other phase of conductors on the same towers impact the potential distribution of insulator strings more uneven. The tower make obvious effect for potential distribution of insulator strings too. Ignored the impact of
According to the actual situation of the insulators, insulator three-dimensional electric field computation models considering the effects of tower, bundle conductors, grading ring, shielding line and so on were set up based on the finite element method. That used to determine the voltage distribution of insulator strings for 750kV transmission lines. The impact of some factors, such as bundled conductors, tower, shield line, grading ring, the type of insulators, material of insulators, insulator suspension mode, conductor arrangement and so on, on the potential distribution of insulator strings located in different position were analyzed and the structure of grading ring was optimized, and then the curve of potential distribution of the insulator strings for different tower, different number of insulators, different types of insulators and different materials of insulator of 750kV transmission lines was determined. The results showed as follows.
③ 增加绝缘子片数，对靠近杆塔侧的绝缘子承担电压降低效果比导线侧更明显， 而且绝缘子片数越多，其电位分布越不均匀。
④ 同塔双回线杆塔上相绝缘子串电位分布最为均匀，中相绝缘子串电位分布最不 均匀；转角塔绝缘子串电位分布比直线塔更为均匀；对于单回线杆塔，中相串的单片绝 缘子承受最大电压值比边相串高；V 串布置时绝缘子串分布电压比 I 串时更不均匀；随 着绝缘子片数的增加单回线杆塔绝缘子串电位分布不均匀度增大比双回线杆塔更明显。
关键词：750kV 输电线路，绝缘子串，电压分布，三维模型，影响因素
I
重庆大学硕士学位论文
ABSTRACT
The insulators is one of the key components for overhead transmission, and the performance of insulators will directly affect the safe operation of the entire line. The stray capacitance which between the insulators and tower and conductors make the voltage distribution along the insulator string uneven. The 750kV power grid will become the main grid in Northwest China, with the construction of 750kV power grid in anywhere of Northwest of China. The insulator strings is longer and the type of insulator is various, which make the voltage distribution of insulator strings more uneven and Implementing the measures to improving the voltage distribution is difficulty. Therefore, to determine the potential distribution of insulator string is very important to detect the poor insulator and safety and stable operation of transmission line. There is on standard voltage distribution of insulator string for 750kV transmission lines, which is not conductive to detect the poor insulators and affect the safe operation of the transmission lines.
2010-05
中文摘要
摘要
绝缘子是架空输电线路的关键部件之一，其性能的优劣直接影响到整条线路的安全 运行。由于绝缘子串与导线、铁塔及金具之间杂散电容的存在，使得沿绝缘子串的电压 分布不均匀。随着 750kV 电网建设在西北五省的全面展开，750kV 电网将成为我国西北 地区的主网架。750kV 输电线路采用的绝缘子串属于超长串、绝缘子型号及规格多样， 绝缘子串电压分布不均匀更加突出，均压措施实施复杂、困难。因 此 ， 确 定 绝 缘 子 串 电位分布，对检测低、零值绝缘子，确保输电线路的安全、稳定运行具有重要的 意义。750kV 交流超高压输电线路运行至今，还没有绝缘子串分布电压的标准，这不利 于对绝缘子串中劣化绝缘子的判别，影响线路的安全运行。
① 仿真计算时，分裂导线对绝缘子串电位分布计算影响明显，它能够使绝缘子串 电位分布更加均匀化；当分裂导线长度取为绝缘子串长的 8 倍以上时，与实际导线的效 果类似；考虑同一杆塔上的其他相导线的影响时绝缘子串电位分布更加不均匀。铁塔对 绝缘子串电位分布影响明显，忽略铁塔影响时绝缘子串电位分布会更加不均匀，特别是 对靠近接地端的绝缘子承受电压影响显著。避雷线、绝缘子伞形结构、绝缘子串的悬挂 方式、导线排列方式、绝缘子材质等因素对不同位置的绝缘子串电位分布的计算均有影 响。
③ Increasing the number of insulator could reduce the withstand voltage of single insulator. But that only make obvious effect for the insulators which near by the tower and not effect for the side of conductor. The potential distribution of insulator strings is more and more uneven when increase the number of insulator.
② 对 瓷 / 玻 璃 绝 缘 子 均 压 环 上 抗 位 置 在 2~3 片 绝 缘 子 处 ， 环 径 取 为 900mm~1000mm，环管径取为 100mm~120mm 绝缘子串电位、电场分布更为均匀；对 复合绝缘子均压环抬高距 h 取 150mm~300mm、环径 R 取 1100~1300mm、管径 Φ 取 140mm~180mm 时绝缘子各部分表面电场较ห้องสมุดไป่ตู้。
根据 750kV 输电线路线路实际情况，考虑铁塔、分裂导线、均压环、避雷线等因 素的影响，建立了 750kV 输电线路绝缘子串三维电场有限元计算模型，研究确定 750kV 绝缘子串电压分布规律。分析讨论了分裂导线、铁塔、避雷线、均压环、绝缘子型号、 绝缘子材质、悬挂方式、导线排列方式等因素对线路不同位置绝缘子串电位分布仿真计 算的影响，优化了均压环结构，进而确定了不同塔型、不同绝缘子片数、不同绝缘子型 号、不同材质绝缘子的 750kV 输电线路绝缘子串电位分布。主要得到了以下结论：
II
英文摘要
tower, the potential distribution of insulator string will be more uneven, especially take significant for the ground side of the insulator withstand voltage. Other factors such as shield line, the type of insulators, insulator suspension mode, the arrangement of conductors, material of insulators and so on, have influence on the potential distribution of insulator strings.
② The best parameter of grading ring to control the electric field distribution of insulators for porcelain or glass insulators is that the position of ring is located between the second and third insulator，and the diameter of grading ring is taken as 900mm~1000mm, and the caliber of grading ring taken to be 100mm~120mm. And the best for the composite insulators is that the value range of h is 150mm~300mm, 1100mm~1300mm for R and Φ is taken as 140mm~180mm.
① The bundle conductor make obvious effect for potential distribution of insulator strings. It can make the potential distribution of insulator string more uniform. The results show that if the length of conductor is more than 8 times of the length of insulator strings, the effect of conductor is equivalent with the actual wire. The other phase of conductors on the same towers impact the potential distribution of insulator strings more uneven. The tower make obvious effect for potential distribution of insulator strings too. Ignored the impact of
According to the actual situation of the insulators, insulator three-dimensional electric field computation models considering the effects of tower, bundle conductors, grading ring, shielding line and so on were set up based on the finite element method. That used to determine the voltage distribution of insulator strings for 750kV transmission lines. The impact of some factors, such as bundled conductors, tower, shield line, grading ring, the type of insulators, material of insulators, insulator suspension mode, conductor arrangement and so on, on the potential distribution of insulator strings located in different position were analyzed and the structure of grading ring was optimized, and then the curve of potential distribution of the insulator strings for different tower, different number of insulators, different types of insulators and different materials of insulator of 750kV transmission lines was determined. The results showed as follows.
③ 增加绝缘子片数，对靠近杆塔侧的绝缘子承担电压降低效果比导线侧更明显， 而且绝缘子片数越多，其电位分布越不均匀。
④ 同塔双回线杆塔上相绝缘子串电位分布最为均匀，中相绝缘子串电位分布最不 均匀；转角塔绝缘子串电位分布比直线塔更为均匀；对于单回线杆塔，中相串的单片绝 缘子承受最大电压值比边相串高；V 串布置时绝缘子串分布电压比 I 串时更不均匀；随 着绝缘子片数的增加单回线杆塔绝缘子串电位分布不均匀度增大比双回线杆塔更明显。
关键词：750kV 输电线路，绝缘子串，电压分布，三维模型，影响因素
I
重庆大学硕士学位论文
ABSTRACT
The insulators is one of the key components for overhead transmission, and the performance of insulators will directly affect the safe operation of the entire line. The stray capacitance which between the insulators and tower and conductors make the voltage distribution along the insulator string uneven. The 750kV power grid will become the main grid in Northwest China, with the construction of 750kV power grid in anywhere of Northwest of China. The insulator strings is longer and the type of insulator is various, which make the voltage distribution of insulator strings more uneven and Implementing the measures to improving the voltage distribution is difficulty. Therefore, to determine the potential distribution of insulator string is very important to detect the poor insulator and safety and stable operation of transmission line. There is on standard voltage distribution of insulator string for 750kV transmission lines, which is not conductive to detect the poor insulators and affect the safe operation of the transmission lines.