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首页> 外文会议>Proceedings of the ASME/IEEE joint rail conference 2009 >ARC FLASH HAZARD ANALYSIS IN TRACTION POWER SUBSTATIONS
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ARC FLASH HAZARD ANALYSIS IN TRACTION POWER SUBSTATIONS

机译：牵引动力变电站电弧闪危险分析

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Arc flash hazards can result from accidents or equipment deterioration such as dropping tools, accidental contact with electrical equipment, build up of conductive dust, corrosion, condensation, over-voltage stress, or insulation failure. An arc is produced when electric current passes through ionized air after an initial flash over or short circuit, resulting in a flash that could produce significant heat, with temperature in excess of 35,000°F. The extremely high temperature of an electric arc can cause major burns within ten feet and fatal burns within five feet of an arc flash.rnRecently enacted guidelines and regulations by OSHA and NFPA 70E regarding arc flash hazards have compelled many rail transit agencies to require that an arc flash hazard analysis be performed. The purpose of this analysis is to determine the potential risk of arc faults at every switchgear and electrical panel board to which a worker may be exposed. To comply with OSHA and NFPA, appropriate work practices and personal protective equipment (PPE) must be utilized to reduce the risks associated with arc flashes.rnSeveral methods for calculating the arc-flash hazard have been developed. This paper will examine and discuss the following three methods: a) the Ralph H. Lee's theoretical model, b) the NFPA 70E equations and tables, and c) the IEEE Std 1584 methods.rnNone of the above methods addresses arcing faults in DC switchgear. To date, there is no written standard for DC arc flash hazard analysis. DC arcing faults and calculation methods are discussed. Sample arc flash hazard analysis from a recent rail transit project is included.
机译：意外事故或设备损坏（例如工具掉落，与电气设备的意外接触，导电灰尘的堆积，腐蚀，冷凝，过电压应力或绝缘故障）可能导致电弧危险。初始闪络或短路后，电流流过离子化空气时会产生电弧，从而导致闪络，该闪络可能会产生大量热量，温度超过35,000°F。电弧的极高温度会在电弧闪光的十英尺内造成严重的灼伤，在五英尺的范围内造成致命的灼伤。rnOSHA和NFPA 70E最近颁布的有关电弧闪光危害的准则和规定已迫使许多铁路运输机构要求进行弧闪危险分析。该分析的目的是确定可能会使工人接触到的每个开关柜和配电板的电弧故障的潜在风险。为了遵守OSHA和NFPA，必须采用适当的工作规范和个人防护设备（PPE）来减少与电弧有关的风险。rn已经开发了几种计算电弧危险的方法。本文将研究和讨论以下三种方法：a）Ralph H. Lee的理论模型，b）NFPA 70E方程和表格，以及c）IEEE Std 1584方法。rn以上方法均不能解决直流开关设备中的电弧故障。迄今为止，还没有关于直流电弧闪光危险分析的书面标准。讨论了直流电弧故障和计算方法。包括来自最近的一个轨道交通项目的示例弧闪危害分析。

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