According to the characteristics of live working on 500 kV compact transmission lines in high altitude (less than 2 800 m) area of Yunnan Power Grid,a series of experiments have been carried out at outdoor proving ground of Kunming UHV Test & Research Base.On the basis of the calculation and analysis of switching overvoltage occurred in UHV transmission lines,the hazard rate of approach distance and complex gap of live working under the specific work position of various operation modes at high altitude area was acquired according to test results.This article proposes a novel method for determining the minimum approach distance of living work,which is based on the analysis of the variation tendency of hazard rate.This method clearly shows the relationship between hazard rate and distance,so that the optimization of verification mode for the distance of live working can be performed.The results show that it is safe and feasible to carry out live working on photogenic and lower phase conductor of 500 kV compact tangent towers in Yunnan Power Grid.Research results are able to provide reference to maintenance and live working on compact 500 kV transmission line in high altitude area.%针对云南电网高海拔(2800 m及以下)紧凑型500 kV线路带电作业特点,在昆明特高压基地户外试验场进行了一系列试验研究.结合操作过电压计算,对不同工作方式下具体作业位置的带电作业安全距离与组合间隙进行了危险率计算.依据危险率变化趋势,综合确定了最小安全距离的新方法.该方法清晰地表现了危险率与间隙距离的关系,便于优化带电作业间隙的校核方式.计算结果表明,云南电网高海拔紧凑型500 kV线路直线塔边相和下相带电作业是安全可行的.研究结果可为电网开展运行维护工作提供技术支持,为高海拔紧凑型线路带电作业提供技术参考.
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