中性线故障导致电气火灾事故研究

发布时间：2018-12-13 04:21

【摘要】：随着我国经济的发展和人民生活水平的不断改善，工业用电和家庭用电量逐年增加，各类电气设备、电器产品在生活和生产中被广泛的应用，在给人们生活和社会生产带来极大方便的同时也留下了安全隐患。在我国的火灾中，电气火灾一直是引发火灾并造成重大伤亡的主要原因。而在电气火灾中，电气线路是最主要的起火源，所占比例高达60%以上。现在的低压配电系统中大多采用三相五线制，中性线在这种配电方式中的作用非常重要，但也常常被人们所忽视，由中性线过载引起的火灾也时有发生，所以对中性线导致火灾事故发生的研究势在必行。通过文献分析和实际调查得知，中性线引发火灾事故主要通过两种途径，一种是中性线长期过载导致中性线绝缘层老化，最后使得绝缘层燃烧引发火灾；第二种是，中性线过故障使中性线开路，导致三相电严重不平衡，烧毁电气设备引发火灾。中性线过载是导致电气火灾的的主要原因，通过研究发现中性线过载的原因是三相不平衡和电路中大量的谐波电流。对当代电气设备故障的红外检测的方法进行了归纳概括。对影响电气红外检测的因素进行了分析。电气设备红外诊断方法主要有温度判断法、相对温差法、同类比较法、档案分析法这四种。经过分析，最适合商场中性线红外检测的方法是相对温差法，该方法比较实用而且误差小。采用红外线测温仪和钳形电流表对商场的中性线进行了检测，，主要测定了三相线和中性线的温度与电流大小。对测得数据进行了分析，算出电路的三相不平衡度和中性线的相对温差，对所测中性线导致火灾的风险大小进行了评估。对商场进行调查，找出了导致中性线过载的原因。根据大型综合商场的特点，从安全技术、教育和管理三方面提出防治中性线导致电气火灾的建议措施。
[Abstract]:With the development of economy and the improvement of people's living standard, industrial and household electricity consumption is increasing year by year. All kinds of electrical equipment and electrical products are widely used in daily life and production. While bringing great convenience to people's life and social production, it also leaves a hidden danger of safety. Electrical fire is the main cause of fire and heavy casualties in China. In electric fire, electrical line is the main source of fire, accounting for more than 60%. Nowadays, most of the low-voltage distribution systems use three-phase five-wire system. The role of neutral line in this mode of distribution is very important, but it is often ignored by people, and fires caused by overload of neutral line also occur from time to time. So it is imperative to study the fire accident caused by neutral line. Through literature analysis and actual investigation, it is found that fire accidents caused by neutral wire are mainly through two ways, one is that the long term overload of neutral line leads to the aging of insulation layer of neutral wire, and finally, the burning of insulation layer causes fire. The second is that the fault of the neutral line causes the neutral line to open the circuit, which leads to the serious imbalance of the three-phase electricity and the fire caused by the burnout of the electrical equipment. Neutral line overload is the main cause of electrical fire. It is found that the cause of neutral line overload is three-phase imbalance and a large number of harmonic currents in the circuit. The infrared detection method of modern electrical equipment fault is summarized. The factors influencing the electrical infrared detection are analyzed. There are four methods for infrared diagnosis of electrical equipment: temperature judgment method, relative temperature difference method, similar comparison method and file analysis method. Through analysis, the method of relative temperature difference is the most suitable method for infrared detection of neutral line in shopping mall. This method is practical and has small error. Infrared thermometer and clamp ammeter are used to detect the neutral line of the shopping mall, and the temperature and current of the three-phase line and neutral line are mainly measured. The measured data are analyzed and the three-phase unbalance degree and the relative temperature difference of neutral line are calculated. The risk of fire caused by the measured neutral line is evaluated. Investigation of the shopping mall to find out the cause of the neutral line overload. According to the characteristics of large comprehensive shopping mall, the paper puts forward some measures to prevent and cure electric fire caused by neutral line from three aspects of safety technology, education and management.
【学位授予单位】：中国地质大学（北京）
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：X932

【参考文献】