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| 电压等级和树枝长度对树线单相接触故障引燃松树枝特性的影响 |
| Effect of voltage level and branch length on the ignition of pine branch caused by single-phase tree-line contact fault |
| 投稿时间：2025-08-01 修订日期：2025-09-08 |
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| DOI： |
| 基金项目:国家电网有限公司科技项目(5419-202243074A-1-1-ZN) |
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| 中文关键词: 森林火灾 树线接触 单相故障 故障强度 引燃时间 |
| 英文关键词:wildfire tree-line contact single phase fault fault intensity ignition delay time |
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| 中文摘要: |
| 在大风或树木生长作用下,树枝可能与架空配电导线发生树线单相接触故障,带来森林火灾隐患。导线电压等级和树枝长度是树线接触故障引燃的重要影响因素。本工作基于模拟实验,研究上述因素对树线接触故障引燃松树枝特性的影响。研究表明,电压等级小于6 kV时无法引燃树枝,在这些未引燃工况中,树线接触点周围的树枝温度低于350 ℃。在引燃工况中,树线接触引燃树枝会发生水分蒸发、木材炭化和火焰燃烧等过程,水分蒸发初期和后期分别由电弧高温和电流焦耳热控制,木材炭化由电弧高温引发,火焰燃烧则是电弧和电流共同诱发。树线接触故障电流在闪络击穿前呈现“增大-减小-增大”三阶段变化,分别受控于树枝温度升高、水分蒸发和炭化过程。故障电流强度与电压等级正相关,与树枝长度负相关。研究结果有助于加深对树线接触故障诱发树枝着火特性的认识,并为防范此类火灾提供理论指导。 |
| 英文摘要: |
| Tree branches may come into contact with overhead distribution conductors due to strong winds or tree growth, which would result in single-phase tree-line contact faults, posing a risk of initiating wildfires. The voltage level and the branch length significantly influence the likelihood of ignition from such a fault, which is studied experimentally in this work. It is found that the voltages below 6 kV were incapable of igniting the pine branches. In the non-ignition cases, the temperature of the branch near the contact point is lower than 350 °C. In the ignition cases, the ignition by a tree-line contact fault undergoes three processes of moisture evaporation, wood charring and flame combustion. The moisture evaporation is dominated by arc heating and Joule heating at the initial and later stages, respectively; the wood charring is caused by arc heating; and the flame combustion is triggered by both arc heating and Joule heating. The fault current exhibits an pattern before flashover, sequentially governed by three distinct mechanisms: temperature rise, moisture evaporation, and branch charring. The fault current intensity was found to show a positive correlation with the voltage level and a negative correlation with the branch length. These findings can enhance our understanding of the mechanism of ignition induced by tree-line contact faults and provide theoretical guidance for wildfire prevention. |
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