Numerical Calculation of Bundle Conductor Surface Electric Field on Transmission Tower Based on Boundary Element Method

摘要

In order to accurately calculate the electromagnetic environment near transmission lines and provide a reference for optimizing the tower and the line, we numerically analyze the electric field on the surface of the bundle conductor near the transmission tower. According to the characteristics of the tower, assuming that tower model consists of a series of cylindrical conductors, a cylindrical conductor is set as a line element, and the bundle conductor surface is set as a plane element. The tower and wire system, as a whole, are calculated with the line-plane mixed boundary element method. According to the characteristics of the conductor surface subdivision unit, improvement measures are proposed on the Gauss integral method.Namely, increasing Gauss points on the long direction of the split unit to reduce the computational memory and improve efficiency, meanwhile, considering the effects of transmission lines on both sides of the calculation model and the earth mirror. The calculation results show that the line-plane boundary element method can calculate bundle conductor surface electric field distribution near the tower more accurately and effectively; Bundle conductor surface electric field near the tower will be significantly increased, and as it is more and more away from the tower, the tower impact decreases rapidly, and the influence of the towers in the middle phase conductor is relatively large. Under normal circumstances, when the aspect ratio is less than 16 times, the Gauss quadrature value of the calculation result is rather accurate. After Gaussian integral is improved, when the aspect ratio of split unit is 64 times, the value of the result is still relatively accurate. So, the accuracy and efficiency are significantly improved; When the distance between the semi-infinite wire and computing point is relatively close, the impact on the calculation result is relatively remarkable.When the distance is relatively far, the impact is relatively small.

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