Research On Wind Deflection Characteristics Of Transmission Lines And Wind Deflection Prevention Performance Of Insulators

With the development of China’s economy,industrial and domestic use of electricity is increasing,China’s uneven regional distribution of electrical energy resources is a more serious problem,as the main carrier of electrical energy transmission lines,its scale is also rapidly expanding.Therefore,cross-regional long-distance transmission is indispensable,and the safe and smooth operation of transmission lines is of paramount importance.However,due to the highly flexible structure of the transmission tower lines themselves,they are subject to dynamic influences,especially wind loads.Transmission lines in the wind load under the role of out-of-plane swing,resulting in line and tower gap reduction,less than the electrical allowable minimum air gap caused by the wind bias fault occurs from time to time,which will lead to a sudden trip of the transmission line,and wind bias fault generated by the tripping blackout automatic closing probability is low,therefore,the transmission line caused by the wind bias fault,to the smooth power supply of the grid brings great challenges,will also cause greater economic and national interest.This paper takes the wind deflection fault tripping of 110 k V Baoyu Line 2 in Urumqi of Xinjiang Power Grid as the engineering background.For the wind-deflection fault-prone Xinjiang region,the wind-deflection fault case analysis is carried out,the analysis of wind-deflection influencing factors of transmission lines and the mechanism research,and the composite wind-deflection insulator is used for wind-deflection management of the tower-line system,and the analysis of the effect of the composite wind-deflection insulator against wind-deflection and its influencing factors.To achieve the prevention and control of wind deflection of transmission lines in windy areas such as Xinjiang,which are prone to wind deflection faults,and then put forward corresponding suggestions for reducing wind deflection faults.The conclusions are as follows:(1)The tower line system was modelled by Abaqus,the numerical wind speed was simulated by Matlab,wind loads were generated,and static and dynamic simulations were compared and analysed.It is concluded that the wind deflection empirical calculation is less accurate when the effect of pulsating wind is ignored,but the maximum angle of wind deflection is about 1.3 times of the empirical calculation method under the effect of pulsating wind speed,and the wind deflection dynamic amplification factor is derived.The effect of stall spacing and insulator string length on wind deflection is small,but when the stall spacing is large,the effect of stall spacing on wind deflection angle is not negligible.When the wind speed is small,the effect of insulator string length on the wind deflection angle is not negligible.Finally,the wind angle of attack has a greater influence on the wind deflection of the insulator string,and the wind deflection correction coefficient of the wind angle of attack is taken as 1-1.6 linear interpolation between the wind angle of attack of 0° and 60°.(2)The wind deflection fault characteristics are analysed and a composite wind deflection insulator is proposed for wind deflection control.The composite wind deflection insulator consists of a diagonally braced strut insulator bar with a composite anti-phase damper at the end.The composite anti-phase damper consists of SMA coil springs and MRF magneto-rheological fluid dampers.The composite anti-wind deflection insulator is diagonally braced at the bottom end of the insulator to the cross-strut.Wind deflection simulations of the tower line system with the composite insulators were carried out by Abaqus to analyse their anti-wind deflection effect.The results show that the composite wind deflection insulator has a good effect can reach 95%on wind deflection and can play a good role in suppressing wind deflection.(3)An analysis of the factors affecting the effect of composite wind deflection insulator structure and material-related parameters on the effect of wind deflection was carried out.It is concluded that the yield strength of the magnetorheological fluid magnetic field is positively related to the effect of wind deflection,but as the yield strength increases,the effect of wind deflection increases less and less;the shape memory alloy mainly plays the role of deformation recovery,and its equivalent stiffness has less influence on wind deflection;the effective length of the piston is positively related to the effect of wind deflection,but when its length exceeds 50 mm,its length has less influence on wind deflection and can be ignored;the piston The gap width is negatively related to the wind deflection resistance effect and has a greater influence,and its wind deflection resistance effect decreases more and more.The analysis of the parameters provides a reference for the design of wind deflection resistant insulator structure.