特高压复合横担带电作业工况下人体放电附着点计算研究

A Novel Method of Discharge Attachment Point Prediction for Live-Line Worker in UHV Composite Cross Arm

特高压复合横担带电作业方式与常规塔型存在较大不同,组合间隙的放电特性尚不明确,识别放电初始附着点对确保人员与设备安全具有重要意义。笔者根据实际1000 kV特高压复合横担搭建了基于先导放电理论的带电作业计算模型,通过计算作业人员体表尖端部位稳定先导起始所需的最小背景电场,分析了不同工况下进出等电位的作业人员体表放电附着概率分布。结果表明:作业人员体表稳定先导始发背景电场较小的部位更易成为放电初始附着点;沿复合横担路径时,作业人员体表初始放电最易附着于手部,其余突出部位放电附着概率相对于手部均达到69%以上;沿垂直向上路径时,初始放电最易附着于头部,下肢相对于头部的放电附着概率小于60%;沿垂直向下路径时,脚部最易成为放电初始附着点,其余部位相对于脚部的放电附着概率均小于65%。在带电作业过程中需针对作业人员放电附着概率较高的部位调整作业人员的进入等电位路径、作业姿态和空间占位。

The live working method of UHV composite cross arm is quite different from the conventional tower type,and the discharge characteristics of the combined gap are not clear.Identifying the initial dis-charge attachment point is of great significance to ensure the safety of the worker and equipment.Based on the actual 1000 kV UHV composite cross arm,a calculation model of live working based on the leader discharge theory is established.By calculating the minimum background electric field required for the sta-ble leader initiation at the tip of the operators body surface,the discharge attachment probability distribu-tion when the worker access to the equipotential under different working conditions is analyzed.The re-sults show that the position with a lower background electric field required for leader initiation is the more likely to be the initial attachment point of discharge;Along the path of composite cross arm,the body part most prone to initiate a discharge is the hand,and the discharge probability of the other protruding parts is more than 69%relative to the hand;Along the vertical upward path,the probability is highest for the head as an initial discharge attachment point,and the probability of the lower limb relative to the head is less than 60%;Along the vertical downward path,the feet is the most likely to initiate a process of discharge,and the discharge attachment probability of other parts relative to feet is less than 65%.In the process of live working,it is necessary to modify the equipotential entering path,posture and space occupation of operators for the parts with high discharge attachment probability.