Research On The Safety Impacts Of Overhead Transmission Line Surrounding Objects To Line Based On Laser Scanning Data

Power is transmitted through the transmission line. So the safe operation of the overhead transmission line is directly related to whether the user can normally accept power. With the rapid development of economic, the demand for electricity is more increasingly. Overhead transmission lines are getting longer and longer. And transmission lines are crossing more and more complexly terrains. So the distance between transmission lines and its surrounding objects are increasingly difficult to determine. There is a strict limit distance between the transmission line and its surrounding objects, in accordance with standard DL/T 741-2010.When the distance between the transmission line and its surrounding objects is smaller than the standard, and transmission line may be failure. More seriously, power interruption maybe happen. Based on this reason, author analyzes the security issues of the distance between overhead transmission lines and its surrounding objects, including building triangular mesh of the overhead transmission lines surrounding objects, the author uses the method of successive approximate to calculate the minimum distance between overhead transmission lines and its surrounding objects. Then, author discuss the transmission lines galloping in order to calculate the minimum distance between lines and its surrounding objects when the lines galloping; Third, author study the growth of trees to calculate the minimum distance between the trees and the lines when the trees growing; last, author using corresponding electric power industry standard judge the safe distance between overhead transmission line and its surrounding objects.This paper proposes a method to calculate the minimum distance between the transmission line and its surrounding objects. This method is based on the laser scanning data about transmission line and its surrounding objects. The laser scanning data contain the three-dimensional coordinates of the ground, trees, buildings, etc. This method can be isolated a single transmission line points within a single span and fitted curves. For the points near the transmission lines, for example, establishing triangular mesh with trees points, calculating the minimum distance between the transmission line and its surrounding objects through the successive approximation method. Experiments show that the minimum distance using this method to calculate comparison with the measured minimum distance, the difference is small, so can be used in practical engineering.Because transmission line galloping will cause the minimum distance between the transmission line and its surrounding objects changes, maybe cause the transmission line security risk. So we study the transmission line galloping. The paper also proposed the transmission line galloping models about equal height adjacent towers of transmission line and unequal height adjacent towers of transmission line. And taking unequal height adjacent towers of transmission line as example simulated the transmission line galloping. Experiments show that the result is consistent with theoretical result.The distance between the transmission line and its surrounding objects such as trees will change with the growth of the trees, and when the distance between transmission lines and trees is less than the standard, the tree flash maybe cause, severely, power outages maybe happen. So we study tree growth, established the gray prediction model of tree growth. Experiments show that the forecasted height of tree growth using this method comparison with the measured, the difference is small, so can be used in practical engineering.This paper presents a method of computing overhead transmission line sag. The overhead transmission line sag can be calculated based on the transmission line point cloud data using the method proposed. The minimum distance between overhead transmission line and the ground, transmission line surrounding objects after taking into account transmission line sag is considered. The minimum distance between overhead transmission line and its surrounding objects according to power industry standard can be determined. Then the distance security implications of the overhead transmission line surrounding object to line is solved completely. So this study has practical value.