2013 m海拔高度植被火条件下导线-板间隙击穿特性

Breakdown Characteristics of Conductor-plane Gap Under Vegetation Fire at the Altitude of 2013 m

架空输电线路受山火影响可能发生跳闸停运,严重影响电网的安全稳定运行。目前关于模拟山火降低空气间隙绝缘强度的研究中未考虑海拔高度的影响,高海拔地区山火条件下的输电线路绝缘强度评估缺乏依据。文中利用模拟山火试验平台,研究了23 m和2013 m海拔地区杉木垛火焰的燃烧特性和空气间隙击穿特性的差异。研究结果表明:火焰温度与高度呈线性变化,高海拔地区火焰中心温度比低海拔地区约低18.3%;低海拔地区放电电弧通道直径更粗、温度更高,高海拔地区预放电所需的电压更低;两个典型海拔地区的火焰主体部位击穿电压梯度基本一致,平均为60.5k V/m;火焰主体部位不需进行海拔修正,火焰非主体部位进行海拔修正时需要同时考虑空气密度、带电粒子和颗粒物的影响,空气密度降低为主要因素,海拔越高,颗粒物的影响程度越大。研究成果可为高海拔地区输电线路山火防控提供参考。

Overhead transmission lines may trip and shut down under the influence of forest fire,which seriously threatens the safe and stable operation of power grid.At present,the influence of altitude is not taken into account in the study on the reduction of air gap insulation strength by simulating forest fire,and there is no basis for the evaluation of insulation strength of transmission lines under forest fire conditions in high altitude areas.The differences of burning characteristics and air gap breakdown characteristics of Chinese fir crib flame at altitudes of 23 m and 2013 m were studied by using a simulated forest fire test platform in this paper.The results show that the flame temperature changes linearly with height,and the flame center temperature at high altitude is 18.3%lower than that at low altitude.The discharge arc channel is thicker and the temperature is higher at low altitude,and the voltage required for pre-discharge at high altitude is lower.The breakdown voltage gradient of the main part of the flame at two typical altitudes has a negligible difference,with an average of 60.5 k V/m.The main part of the flame does not need altitude correction.The influences of air density,charged particles and particulate matter should be considered when correcting the altitude of the non-main part of the flame.The decrease of air density is the main factor,and the higher the altitude,the greater the influence of particulate matter.The research results can provide references for forest fire prevention and control of transmission lines in high altitude areas.