Transfer Matrix Method Of Bundle Conductor Vibration Mode

The accurate calculation of the vibration mode of the bundle conductor is of great significance to the analysis and suppression of the breeze vibration and galloping.Using transfer matrix method,the vibration characteristics of subspan could be expressed by a field transfer matrix,and the spacer characteristics could be expressed by a point transfer matrix.Establish from the beginning to the end of the whole span vibration expression,combined with the boundary conditions,the system c an be solved.Set up field transfer matrix and point transfer matrix combining the theory of string vibration and the constraint relation between spacer and wires.The mathematic expression is solved by MATLAB software to get the order frequency value,and the frequency information is brought into the formula system to draw the corresponding vibration mode diagram.The transfer matrix method is used to solve the vibration mode of the bundle conductor.The results of modal analysis are shown: Bundle conductor vibration frequency is generally in the 0.1Hz-0.2Hz,At the fifth step,the split vibration modes begin to appear,and there is a frequency-intensive region.There are four types of typical vibrations in the case of double-bundle conductors,which are summarized as in-plane vibration,out-of-plane vibration,split vibration and torsional vibration.For a four-bundle conductor,there are six typical vibrations,including in-plane vibration,out-of-plane vibration,and four types of splitting vibration.The in-plane vibration and out-of-plane vibration belong to the full-span vibration,showing similar vibration characteristics to single-strand wire.Split vibration is a special form of vibration of bundle conductor,there is relative motion between its sub-conductor.There is relative movement between the sub-wire,the installation of the bar at the prone to fatigue damage.In addition,the spacer bar restricts the relative movement of the sub-conductors,which has a certain degree of suppression of the wire vibrations.The vibration mode of bundle conductor was analyzed by ANSYS software.The main steps are finite element modeling,form finding and modal solving.The results of ANSYS analysis are compared with those of transfer matrix method.The relative error of each order frequency is about 10%,and the mode shape coincides with each other.It is verified that the transfer matrix method is reliable to calculate the vibration mode of the bundle conductor,and the transfer matrix method can be used to modulate the bundle conductor in a fast and effective way.