Design Of Spacer Bar Based On Electromagnetic Damping And Spring Composite And Its Anti-Dancing Research

High-voltage overhead transmission lines in high winds,icing and other special meteorological conditions,will produce a low-frequency,large amplitude dance phenomenon.The phenomenon can cause fatigue breakage of the line and damage to the fixtures,etc.,which has a serious impact on the safety of power supply.For the problem that the spacer bar can limit the relative motion of splitting wires,but cannot effectively track the kinetic energy change of transmission lines to provide dance suppression damping force,this paper combines two mechanisms,electromagnetic damping arm and spring,and designs a damping damping system in two directions,vertical and horizontal,inside the spacer bar.The process of generating damping force by electromagnetic damping arm is simulated and analyzed by using finite element analysis method,and the suppression effect of electromagnetic damping spacer bar and common spacer bar on transmission line dance is studied in comparison.The specific research includes the following aspects:(1)A new electromagnetically damped spacer bar is designed by organically combining the spring limiting effect and the eddy current effect of electromagnetism,and the function of damping and vibration reduction is realized in the spacer bar arm.This damping structure designs permanent magnets as the magnetic source and uses the relative motion between the permanent magnets and the damping barrel to generate damping force,which has the advantages of long life and simple working principle.Based on the steady-state assumption and the basic principle of electromagnetism,the mathematical model of electromagnetic damping arm and spacer bar is established in an analytical way,and the vibration absorption and damping effects of the new electromagnetic damping spacer bar are analyzed,and the influence law of damping ratio,inherent frequency ratio and mass ratio on the damping performance is given.(2)The finite element model of the electromagnetic damping arm is established,and for different magnetic circuit design schemes,suitable structural parameters such as magnet magnet charging method,air gap,damping cylinder thickness and permanent magnet material are selected,and their magnetic field distribution under steady state conditions are compared and analyzed.The energy dissipation process of the electromagnetic damping arm under the system instability condition is analyzed,and the kinetic characteristics of the electromagnetic damping arm are obtained.The results indicate that the electromagnetic damping arm has good damping efficiency and energy dissipation capacity.(3)The ordinary spacer bar-wire system model and the electromagnetic damped spacer bar-wire system model were established respectively,and the wind load was applied to the two system models for simulation and analysis,and the displacement time curves of the spacer bar centers of the two systems were obtained.The influence of external wind load,system incoming flow density,wire damping ratio,high voltage overhead line stall distance and split wire spacer stiffness on line dance amplitude is analyzed.The results show that the installation of electromagnetic damping spacer bar of the line in the vertical direction of the amplitude is significantly reduced,the rate of vibration reduction of about 35%.The new electromagnetic damping spacer bar has a more obvious inhibiting effect on the dance.