覆冰导线气动及舞动特性研究

发布时间：2018-05-11 20:24

本文选题：覆冰舞动 + 气动特性　；参考：《华中科技大学》2013年博士论文

【摘要】：输电线路的舞动是低频高幅的自激振动，产生的巨大的能量对输电线路的安全运行造成极大的隐患和危害，随着输电塔高度的增加及输电线路档距的增大，架空输电线高柔的特点更突出，舞动引起的断线及倒塔等严重电力事故频发，对舞动及其控制的研究对输电线路的安全运行具有重要的意义。本文从气动力风洞试验、数值模拟两个方面对覆冰导线的舞动进行了研究，主要内容如下：覆冰引起的气动不稳是输电线路舞动的直接诱因，对覆冰导线气动特性的研究是解决舞动问题的基本，本文首先针对输电线路的经典覆冰类型和风场特性设计了覆冰导线气动特性测力风洞试验，分别进行了均匀流和紊流风场下的测力试验，得到了新月形、扇形、冠形在不同覆冰厚度下的气动特性，并研究了平均风速大小，，紊流效应及二维流场效应等因素对覆冰导线气动特性的影响。其次针对目前覆冰导线气动力特性数据匮乏的特点，采用FLUENT软件进行了新月形、扇形、冠形三种覆冰截面在五种覆冰厚度下的气动特性仿真，基于风洞试验结果验证了数据的可靠性。然后对气动力结果进行了曲线拟合，得出了各覆冰截面在不同覆冰厚度及初始凝冰角下的竖向升力系数公式，丰富了风洞试验的结果，建立了详细的覆冰导线气动力特性数据库。然后本文建立了输电线的单自由度振子数学模型，基于准定常理论采用多尺度方法推导了舞动振幅的解析解，并采用Runge-Kutta方法编制了求解舞动时程的数值仿真程序，与解析结果进行了对比。本文系统的研究了覆冰截面、覆冰厚度、初始凝冰角以及升力曲线阶数等参数对舞动振幅的影响。针对舞动过程中振幅大等特点，提出了一种利用舞动现象进行能量获取的思路，并对不同覆冰形状的截面的能量获取率进行了分析。基于单自由度和两自由度振子系统，给出了舞动稳定性的判别公式。最后采用有限元程序ANSYS/LS-DYNA，建立非线性粘性阻尼器单元来模拟覆冰导线的气动特性，同时在输电塔上施加脉动风时程，进行了输电线舞动以及输电塔随机振动的显式有限元计算。采用本文方法对500kV海门到汕头榕江大跨越工程进行了风振计算，提出了施加防屈曲耗能支撑的控制方案，并对控制方案进行了优化。对压重防舞技术和相间间隔棒防舞技术进行了探讨，给出了防舞方案的优化设计思路，并对Port Credit线路进行了防舞设计。
[Abstract]:The galloping of transmission line is the self-excited vibration of low frequency and high amplitude. The huge energy generated by it causes great hidden trouble and harm to the safe operation of transmission line. With the increase of the height of transmission tower and the increase of transmission line distance, The characteristics of overhead transmission lines are more prominent. The frequent occurrence of serious power accidents such as broken lines and inverted towers caused by galloping is of great significance to the study of galloping and its control for the safe operation of transmission lines. In this paper, the galloping of ice-covered conductors is studied from aerodynamic wind tunnel test and numerical simulation. The main contents are as follows: The aerodynamic instability caused by icing is the direct inducement of transmission line galloping, and the study of aerodynamic characteristics of ice-coated conductors is the basic to solve the galloping problem. In this paper, wind tunnel tests on aerodynamic characteristics of ice-coated conductors are first designed for the classical icing type and wind field characteristics of transmission lines. The force measurement tests under uniform flow and turbulent wind field are carried out respectively, and the crescent and fan shapes are obtained. The aerodynamic characteristics of the coronal shape under different icing thickness were studied. The effects of the mean wind speed, turbulence effect and two-dimensional flow field on the aerodynamic characteristics of ice-coated conductors were studied. Secondly, aiming at the lack of aerodynamic characteristic data of icing conductor at present, the aerodynamic characteristics of crescent section, sector section and coronal section under five kinds of ice thickness are simulated by FLUENT software. The reliability of the data is verified based on the wind tunnel test results. Then the curve fitting of aerodynamic results is carried out, and the formulas of vertical lift coefficient of each icing section under different ice thickness and initial freezing angle are obtained, which enriches the results of wind tunnel test. A detailed database of aerodynamic characteristics of ice-coated conductors is established. Then the mathematical model of single degree of freedom oscillator of transmission line is established, and the analytical solution of galloping amplitude is derived by using multi-scale method based on quasi-steady theory, and the numerical simulation program for solving the galloping time history is compiled by using Runge-Kutta method. The results are compared with the analytical results. In this paper, the effects of icing cross section, ice thickness, initial freezing angle and the order of lift curve on the galloping amplitude are systematically studied. According to the characteristics of large amplitude in the process of galloping, this paper puts forward a method of energy acquisition by using the phenomenon of galloping, and analyzes the energy acquisition rate of the sections with different icing shapes. Based on the system of single degree of freedom and two degree of freedom, the formula of judging the stability of galloping is given. Finally, a nonlinear viscous damper element is established to simulate the aerodynamic characteristics of ice-coated conductors by using the finite element program ANSYS / LS-DYNA.At the same time, the pulsating wind time history is applied to the transmission tower, and the explicit finite element calculation of the transmission line dance and the random vibration of the transmission tower is carried out. In this paper, the wind-induced vibration of 500kV Haimen to Shantou Rong River Crossing Project is calculated, and the control scheme of applying anti-buckling energy dissipation support is put forward, and the control scheme is optimized. This paper discusses the technique of anti-dance of pressure weight and interphase spacer, and gives the optimized design idea of the scheme of anti-dance, and designs the anti-dance of Port Credit circuit.
【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TM752;TU311.3

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