500kV同塔双回输电线路耐雷性能研究

发布时间：2018-05-14 17:52

本文选题：同塔双回 + 耐雷性能　；参考：《长沙理工大学》2014年硕士论文

【摘要】：电力生产是国民经济发展的关键,随着电网建设规模与传输容量的增大,而可用架空输电线路走廊日趋紧张,超高压主干网架将朝同塔双、多回并架方向发展。日本,美国等国超高压电网中多采用同塔双回输电,我国三峡电站及江浙等地也建设了多条500kV超高压同塔双回输电线路。由于500kV同塔双回线路杆塔增高,引雷面积增大而使雷电跳闸率升高,且存在雷电引起绝缘子双回同时闪络跳闸的情况,严重影响电力系统的稳定运行,因此对500kV同塔双回线路进行耐雷性能分析具有一定的工程实践意义。论文以500kV同塔双回输电线路为研究对象,基于ATP-EMTP对500kV同塔双回输电线路反击耐雷性能进行仿真计算时,考虑更接近现场实际的多波阻抗杆塔模型,利用在频域中用有理函数近似处理A(ω)和Zc的J.Marti线路模型,同时用非线性电感模型替代单值电感进行先导闪络模型的仿真研究,考虑了前驱电流的同时避开了参数的预计算,利用统计法,考虑工频电压的影响,计算500kV同塔双回输电线路反击耐雷水平。研究了电气几何模型、分析计算了500kV同塔双回输电线路绕击跳闸率及各类因素对跳闸率的影响,提出了符合现场实践的防雷改造措施。研究结果表明,杆塔高度、冲击接地电阻、工频电压、导线排列方式、避雷线根数、闪络模型等影响因子对线路的反击耐雷性能影响十分明显。随着冲击接地电阻的减低,杆塔高度的降低,输电线路单回和双回跳闸率都显剧降低；工频电压对500kV线路反击耐雷水平有很大的影响,应予以考虑。500kV同塔双回线路导线排列方式对其耐雷水平有影响,导线排列应尽量采用逆相序排列方式,以降低线路跳闸率；3根地线可使总反击跳闸率降至2根地线的89%,双回跳闸率和单回跳闸率均有所降低；用非线性电感建立绝缘闪络模型,提高了500kV同塔双回输电线路耐雷水平仿真计算精度。随着击距系数、风摆角、地面倾角、避雷线保护角的增大,500kV同塔双回输电线路跳闸率明显增加,工频电压对500kV同塔双回输电线路耐雷性能影响明显,在分析500kV线路绕击耐雷性能时,也应充分考虑工频电压的影响。针对典型杆塔计算分析：在雷电过电压作用下,风速达到26.8米/秒时,就可能导致线路跳闸,此计算值可供工程参考。
[Abstract]:Power production is the key to the development of national economy. With the increase of power grid construction scale and transmission capacity, the available overhead transmission line corridor is becoming increasingly tight, and the UHV backbone network frame will develop in the direction of the same tower and double tower and multi-circuit parallel frame. In Japan, the United States and other countries, the same tower and double circuit transmission lines are often used in the UHV power grid. Many 500kV UHV double-circuit transmission lines have also been built in China's three Gorges Power Station and Jiangsu and Zhejiang provinces. The lightning tripping rate is increased due to the increase of the tower of the double circuit line of the same tower of 500kV and the increase of the lightning induced area, and there exists the situation that the insulator flashover tripping simultaneously caused by the lightning, which seriously affects the stable operation of the power system. Therefore, it is of engineering significance to analyze the lightning resistance performance of 500kV dual circuit with tower. In this paper, 500kV double-circuit transmission line with same tower is taken as the research object. When simulating the anti-lightning performance of 500kV double-circuit transmission line based on ATP-EMTP, the model of multi-wave impedance bar and tower which is closer to the actual field is considered. The J.Marti circuit model of A (蠅) and ZC is approximated by rational function in the frequency domain, and the simulation of the pilot flashover model is carried out by using the nonlinear inductance model instead of the single value inductor. The precursor current is taken into account and the pre-calculation of the parameters is avoided. By using statistical method and considering the influence of power frequency voltage, the lightning resistance level of 500kV double-circuit transmission line with the same tower is calculated. This paper studies the electrical geometry model, analyzes and calculates the tripping rate of 500kV double-circuit transmission line and the influence of various factors on the tripping rate, and puts forward the measures of lightning protection in line with the field practice. The results show that the influence factors, such as tower height, impulse grounding resistance, power frequency voltage, conductor arrangement, lightning arrester root number and flashover model, have a significant effect on the anti-lightning performance of the line. With the decrease of impulse grounding resistance and tower height, both single-circuit and double-circuit tripping rates of transmission lines are significantly reduced, and the power frequency voltage has a great influence on the lightning resistance level of 500kV lines. Consideration should be given to the influence of the conductor arrangement mode on the lightning resistance level of .500kV double-circuit transmission line with the same tower, and the reverse phase sequence arrangement should be adopted as far as possible in the conductor arrangement. In order to reduce the line tripping rate and 3 ground wires, the total return tripping rate can be reduced to 89 of 2 ground wires, the double tripping rate and the single tripping rate will be decreased, and the insulation flashover model can be established by nonlinear inductance. The simulation accuracy of lightning resistance level of 500kV double circuit transmission line with same tower is improved. With the increase of strike distance coefficient, wind swing angle, ground inclination angle and lightning protection angle, the tripping rate of 500kV double-circuit transmission line with the same tower increases obviously, and the power frequency voltage has an obvious effect on the lightning resistance performance of 500kV double-circuit transmission line with the same tower. The influence of power frequency voltage should also be taken into account when analyzing the lightning resistance performance of 500kV lines. According to the calculation and analysis of typical pole and tower: when the wind speed reaches 26.8 m / s under the action of lightning overvoltage, it may lead to line tripping, which can be used as a reference for engineering.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM863

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