现行规范规定覆冰输电线路杆塔结构的设计需要考虑一定程度的风荷载的作用。为了研究覆冰输电塔一线风致振动的动力相互作用,以某特高压输变电工程的1000kV同塔双回输电线路为原型,进行了模拟覆冰条件下五塔四线气弹模型的大型风洞试验。试验中严格模拟了输电线路覆冰后的动力特性和气动外形,用等代塔模拟边界条件,研究了塔线耦联体系在均匀流场和紊流场的风致响应。试验测得了覆冰塔线体系的加速度和位移风振响应。相比不覆冰情况,覆冰塔线耦联体系的阻尼比明显增大。将光纤布拉格光栅(fiberBragggrating,FBG)运用于风洞试验,对八分裂导线在风作用下的动应变进行了测试,探究了覆冰导线自身动力特性的变化规律及其在风荷载作用下对特高压输电塔结构的影响。研究结果表明:在覆冰工况下,需要合理考虑脉动风对覆冰塔线耦联体系的动力作用。
The current design code requests that wind actions should be considered in the design of icing transmission tower. Taking 1 000 kV double circuit transmission lines of an ultra high voltage (UHV) transmission project as the prototype, a large wind tunnel test on icing aeroelastic model was carried out to find out the dynamic interaction of 'wind-induced vibration for icing transmission tower-line coupling system. The aerodynamic characteristics of the transmission tower-line system were simulated and the boundary conditions were simulated by the equivalent towers. The vibration response of acceleration and displacement were observed in the test. Compared with its counterpart without icing, it was found that the damping ratio in the icing system increased a lot. The dynamic strains of the eight-bundled conductors were measured by using fiber Bragg grating (FBG). The dynamic property variation of the icing conductor and its impact on the transmission tower under the wind load were investigated. The results show that the reasonable dynamic interaction under turbulence flow in the icing tower-line coupling system should be taken into account.