特高压输电线路舞动特征和激发模式研究

The construction of the UHV transmisison line system is now rapidly developing in China.Galloping may take place frequently on the UHV transmission lines constructed with eight-bundled or six-bundled conductors, because ice with unsymmetric cross-section shape tends to be accreted on these large bundle conductors, and this phenomenon will jeopardize the normal operation of the power supply system.Investigation on the galloping behavior and initiation modes of eight-bundled conductors is focused on in this project.The aerodynamic properties of the eight-bundled conductors covered ice with typical cross-section shapes with different thicknesses and initial angles and in different wind speeds will be measured by the wind tunnel tests, in which wake inference between the subconductors is taken into account.The nonlinear numerical method for the galloping simulation of bundle conductors in stochastic wind field will be developed.Identification methods for the galloping characteristic parameters,such as the frequency, vibration amplitude and phase,and the oscillation mode as well as limit cycle, and coupling behavior between the translational and tornsional movements of the iced conductors during galloping will be investigated.Based on the numerical simulation results of the galloping responses of typical trasnmission line sections with different structural parameters, such as span length,sub-span length,sag and number of spans, in different natural conditions, including the cross-section shape,thikness and initial accretion angle of the covered ice, and wind speed,the gallopoing behavior and initiation modes will be analyzed by means of the developed galloping identification method.The result of this project will provide theoretical foundation for the development of anti-galloping methods. The issue of this project is a key problem in the constrction and operation of the UHV transmission line system in our country.

我国特高压电网建设已进入新时期。特高压输电线路采用八分裂或六分裂导线，其扭转刚度大，更易形成非对称截面形状的覆冰，线路更易发生舞动现象，对特高压电网的安全运行造成严重威胁。本项目拟对特高压八分裂输电线路的舞动特征和激发模式进行系统研究。利用风洞试验研究八分裂导线各子导线在典型覆冰冰型、冰厚、初始凝冰角和不同风速等情况下的空气动力系数，研究上风子导线尾流对下风子导线气动特性的影响；研究覆冰分裂导线舞动非线性数值模拟方法；研究从输电线随机振动响应中识别舞动响应，提取舞动的频率、幅值和相位等特征参数以及导线的振动形态和运动轨迹，分析横向和扭转运动耦合特性的方法；利用获得的舞动特征识别方法，基于不同结构参数线路在不同冰型、冰厚和风速等条件下的舞动数值模拟结果，研究特高压输电线路的舞动特征和激发模式，为特高压舞动防治方法的研究奠定理论基础。本项目研究内容是我国特高压电网建设和安全运行中的关键问题。

我国特高压电网建设已进入新时期。特高压输电线路采用八分裂或六分裂导线，其扭转刚度大，更易形成非对称截面形状的覆冰，线路更易发生舞动现象，对特高压电网的安全运行造成严重威胁。..本项目主要针对特高压输电线路的舞动特征和激发模式进行了系统研究。利用风洞试验测量了新月形、扇形覆冰八分裂导线和八分裂裸导线在不同覆冰厚度、风速和湍流度等条件下各子导线的升力系数、阻力系数和扭矩系数随风攻角的变化规律，为特高压八分裂导线舞动及其防治技术研究提供了必要的数据资料。研究获得了从输电线路随机振动响应中识别舞动响应，提取舞动频率、幅值、相位、振动形态和运动轨迹，以及分析各方向运动耦合特性的方法，该方法可以用于任意分裂导线的舞动研究。采用数值模拟方法和覆冰八分裂导线节段模型驰振风洞试验，研究了特高压八分裂导线的舞动特征和激发模式，重点研究了内共振条件下分裂导线的舞动特征。此外，还对覆冰六分裂导线、四分裂导线和双分裂导线的舞动进行了研究。..本项目研究成果对我国特高压电网建设和安全运行中舞动防治技术的研究奠定了理论基础，具有十分重要的科学意义。