同杆(塔)架设多回路送电线路耐雷水平的分析

Analysis of Lightning－protection Level of Mounting Multiple Power Supply Circuits on a Single Pole

同杆（塔）架设多回路送电线路，三．相导线一般为垂直排列，这就给线路防雷带来了不利因素：一方面增加了杆（塔）的高度；另一方面减小了导线与避雷线间的耦合系数，因此，耐雷水平较低。在采取架设耦合地线[1]，或采用不平衡绝缘方式[1]等措施来增大导地线间的耦合系数；或架设塔顶防雷引下线，[2]来增大杆（塔）的等效截面、减小杆（塔）的等值电感，从而提高同杆（塔）架设多回路送电线路的耐雷水平。

When mounting multiple power supply circuits on a single pole(tower),the threephase wires are usually vertically arranged,thus bringing unfavourable factors to the Iightning -protection. On .one hand,it increases the height of the pole (tower),on the other hand, it decreases the coupled factors between the wire and lightning - protection wire, which results in lower lightning - resistance. In this paper, the writer puts forward a method to trlount coupled ground wire or take measures of unbalanced insulation method to increase the coupled factors of the ground wire,to m0unt lightning-protection wire on top of the pole (tower)to increase the equavalent section, to decrease the equavalent inductance of the pole (tower ). In this way,the Iigthtning- protection is improfved on the single pole (tower)mounted with multiple po wer supply circuits.