【作者】 孙健；

【导师】 李嘉祥； 王述红；

【作者基本信息】 东北大学 ， 岩土工程， 2021， 硕士

【摘要】 输电塔-线体系作为电力输送的载体,不可避免的要穿越气候恶劣的地区,严寒环境作为对输电塔-线体系威胁最大的环境之一,极易造成输电塔-线体系覆冰。覆冰不仅会增加输电线路的荷载,而且极易引发输电线路事故,例如:覆冰脱冰、导线断线、金具损伤、杆件破坏。为了更好的防治输电线路覆冰灾害,保证输电线路的安全运行,本文选取典型的输电线路覆冰事故——覆冰脱落和覆冰断线作为研究对象,对输电线路在这两种典型事故中的动力响应进行研究。本文首先对输电线路覆冰脱落引起的连续倒塌进行了研究,之后对覆冰断线引起的塔-线体系动力响应进行了分析,最后提出了一种减小线路纵向不平衡张力的保护装置,并利用有限元软件ANSYS进行效果模拟并进行装置优化。主要内容和结论如下:以实际工程中的500 kV输电线路为研究对象,使用有限元软件ANSYS建立了两塔三线的输电塔-线体系数值模型,在建模过程中应用一致模态法考虑了输电塔的初始缺陷,对输电线路由覆冰脱落引起的连续倒塌在ANSYS/LS-DYNA中进行了动力分析,并针对档距、绝缘子长度和导线初始张力等参数对塔-线体系的稳定性的影响进行研究。结果表明:脱冰高度越高,导线脱冰对体系的威胁越大;档距越大,绝缘子越短,线路的动力响应越大;输电塔设计中需要考虑到覆冰脱落的冲击作用。建立了设置有加强塔的九塔十线输电线路模型,研究了在覆冰断线条件下加强塔对连续倒塌的抵抗效果和输电线路在断线作用下的动力响应。结果表明:加强塔能够有效阻止输电塔的连续倒塌;在断线分析研究中需要考虑动力冲击作用,在允许范围内,缩小档距,增加绝缘子长度和导线初始张力都能够降低覆冰断线带来的冲击作用。根据上述分析结果,提出了一种减小输电线路纵向不平衡张力的保护装置,可以有效保护输电线路在覆冰脱落和断线下不发生连续倒塌事故。首先分析了该装置的工作机理,之后通过数值方法研究了该装置在覆冰断线工况下的有效性,并进行了参数分析研究了其影响参数。结果表明:该装置在覆冰断线工况下能够有效减小线路中的纵向不平衡张力,同时该装置也能在覆冰脱落中保护线路。更多还原

【Abstract】 As the carrier of power transmission,the tower-line system inevitably passes through the region with bad climate,cold environment,as one of the most threatening environments to the tower-line system,is easy to cause ice covering of the transmission tower-line system.Icing will not only increase the load of transmission lines,but also easily lead to transmission line accidents,such as ice-shedding,conductor ruptuer,metal damage,bar damage.In order to better prevent and control the transmission line icing disaster and ensure the safe operation of the transmission line.In this paper,a typical transmission line icing accident--ice shedding and ice breaking are selected as the research objects to study the dynamic response of transmission lines in these two typical accidents.Firstly,the Progressive collapse of transmission lines caused by ice-shedding is studied,and then the dynamic response of the tower-line system caused by conductor rupture is analyzed.Taking 500 kV transmission line in actual engineering as the research object,the numerical model of two towers and three lines transmission tower-line system is established by using the finite element software ANSYS.In the modeling process,the initial defects of transmission towers were considered by using the uniform mode method,and the continuous collapse caused by ice-shedding of transmission lines was analyzed in ANSYS/LS-DYNA,and the influence of the parameters such as span,insulator length and initial conductor tension on the stability of the tower-line system was studied.The results show that the higher the deicing height,the greater the threat of wire deicing to the system;The larger the span,the shorter the insulator and the greater the dynamic response of the line.The impact of ice-shedding should be considered in the design of transmission towers.A nine-tower and ten-line transmission line model with strengthening tower is established to study the resistance effect of strengthening tower against continuous collapse and the dynamic response of transmission lines under the action of conductor rupture.The results show that the strengthening tower can effectively prevent the continuous collapse of transmission towers.The dynamic impact should be considered in the analysis of the conductor rupture,within the allowable range,reducing the span,increasing the length of the insulator and increasing the initial tension of the wire can reduce the damage impact caused by conductor rupture.According to the above analysis results,a protective device is proposed to reduce the longitudinal unbalance tension of transmission lines,which can effectively protect transmission lines from continuous collapse accidents when the ice falls off and the lines break.Firstly,the working mechanism of the device is analyzed,and then the effectiveness of the device under the condition of conductor rupture is studied by numerical method,and the influence parameters are studied by parameter analysis.The results show that the device can effectively reduce the longitudinal unbalanced tension in the line under the conductor rupture,and the device can also protect the line in the case of ice-shedding.更多还原