易诱发输电线路跳闸的山火时空分布规律及发生频率分析

Temporal-spatial distribution regularity and the liability of the wildfire incidence frequency in inducing the power transmission line electrical trips

基于中国南方电网某公司下属各局所辖区域内自2000年以来山火诱发高压输电线路跳闸事故的统计数据,从季节和月份等时间因素及地势地貌和林分类型等空间因素进行分布规律分析,确定山火诱发同步跳闸频率;为进一步探讨易爆发山火地区存在的问题和安全隐患,利用全国森林火险气象警报图与谷歌地球软件相结合的方法,对南方五省份(广西、广东、云南、贵州和海南)输电线路因山火跳闸的重灾区进行初步识别和划分。结果表明:时间上,可致跳闸的山火爆发具有季节性,一般集中于每年2—4月和每日11:00—18:00,发生频率依次为71.2%和91.2%,而在输电线路因山火跳闸率最高的2月份,云南西北部和广东北部的局部区域森林火险气象等级达到5级;空间上,可致跳闸的山火发生在阳坡的频率为94.1%,其中在缓坡和直线坡发生频率依次为50.0%和55.6%;维持山火可燃物多为桉树等油性速生林,发生频率为58.5%。此外,在地域分布上,云南、广西及南方五省份交界处由于森林覆盖稠密且高压输电线路分布密集,山火诱发跳闸事故较为严重。

The article intends to bring about its study on the temporal-spatial distribution regularity and the liability of the wildfire incidence frequency in inducing the power transmission line electrical trips.For the research purpose,we have first of all managed to have collected the recent statistics of such accidents offered by the administrative department of South China Power Grid.And,then,we have done careful analysis over the distribution regularity of such accidents via the temporal factors（e.g.the seasons and months,etc.） and the spatial factors（e.g.the terrain topography and the wood types,etc.）.The results of the above mentioned statistics and analyses help us to figure out the frequencies of the aforementioned transmission line electrical trips.In order to make out the areas where such wildfires are more likely to come about,we have chosen a method of the Google Earth software combined with the national forest fire weather alert map.As a result,we have found that there are five south China provinces（i.e.Guangxi,Guangdong,Yunnan,Guizhou and Hainan）,which are more likely to be hit by such wildfires.And then we have managed to identify and delimit some other areas which are hardly-hit by such wildfires.Furthermore,we have also made an exploration of the time and seasonal factors in regard to the outbreaks of such wildfires.The results we have found are such that such accidents are most likely to take place from February to April and on a day-time between 11：00 to 18：00 at a respective frequency between 71.2% to 91.2%.And,more specifically speaking,most wildfires inducing the power transmission line trips take place in February.And,in terms of space,northwestern Yunnan and Northern Guangzhou run first with the forest fire with the weather grade being fifth.Furthermore,in terms of the local geographical particularities,94.1% of such wildfires break out in the sunny slope areas,especially in the gentle slope and liner slope areas,which account for 50% and55.6% of the incidence rate of such fires respectively.What is more,we have also found that the areas oil-abundant and thick with fast-growing tree species（like eucalyptus,etc.） are also more likely to be hit by such wildfires.Such areas may account for a frequency rate of 58.5%.All in all,it can be certain that the outbreaks of such wildfires are mostly concentrated in Yunnan and Guangxi as well as the surrounding areas of the aforementioned five south China provinces,particularly in the forest-densely areas with forest plants and transmission line networks.