民用低压直流供电系统电压等级和接地方式研究  

Research on Scheme of Civil Low Voltage DC Power Supply System

作　　者：童亦斌[1] 赵宇明 郝斌 王旭婷 刘毅[1] TONG Yibin;ZHAO Yuming;HAO Bin;WANG Xuting;LIU Yi(National Active Distribution Network Technology Research Center,Beijing Jiaotong University,Beijing 100044,China;Shenzhen Power Supply Bureau Co.,Ltd.,Shenzhen 518001,China;Shenzhen Building Science Research Institute Co.,Ltd.,Shenzhen 518049,China)

机构地区：[1]北京交通大学国家能源主动配电网技术研发中心,北京100044 [2]深圳供电局有限公司,广东深圳518001 [3]深圳市建筑科学研究院股份有限公司,广东深圳518049

出　　处：《供用电》2021年第3期52-60,共9页Distribution & Utilization

基　　金：中国南方电网有限责任公司科技项目“基于直流的综合能源系统关键技术研究与应用”(090000KK52180116)。

摘　　要：电动汽车充电、分布式发电和储能在民用领域具有广阔的推广应用前景,而低压直流系统可以提供更加高效灵活的接入条件,近些年受到广泛关注。由于低压直流供电技术在民用领域的应用经验还比较缺乏,针对电压等级、接地方式和主接线形式等,还未形成比较统一的意见。围绕安全性和经济性这2个核心要素,在总结直流建筑示范项目工程实践经验的基础上,提出触电危险分级标准,用于对供电系统的电击防护性能进行对比,并利用供电负荷距和单位负荷距线缆成本开展经济性评价;在此基础上,以民用建筑为例,梳理了系统方案之间相互影响的关系,介绍了计算方法和选择步骤,给出了电压等级、接地方式和主接线形式的设计建议;最后,针对IT接地系统特点,分析了触电危险隐患及其产生的条件,提出通过工作接地电阻的合理设计,借助剩余电流保护和绝缘监测2种措施的配合,提高IT接地系统电击防护性能,并给出了设计方法。Electric vehicle charging,distributed power generation and energy storage have broad application prospects in the civilian field,and the low-voltage DC systems can provide more efficient and flexible integration conditions,which have received widespread attention in recent years.Because the application experience of low-voltage DC power supply technology in the civilian field is still relatively lacking,unified opinion has not yet been formed on the system schemes such as voltage level,grounding mode,and main connection scheme.Based on the summary of the engineering practice of the DC building demonstration project,the paper proposes an electric shock hazard classification standard for comparing the electric shock protection performance of power supply systems,then using the power supply load distance and the unit load distance cable cost to evaluate the economy.On this basis,taking civil buildings as an example,the relationship between the system schemes is sorted out,the calculation methods and selection steps are introduced,design recommendations for the voltage levels,grounding mode and main connection scheme are given.Finally,according to the characteristics of the IT grounding system,the potential dangers and generating conditions of electric shock are analyzed,a method to improve the protection performance by cooperation of residual current protection and insulation monitoring is introduced,and the design step of the grounding resistance is proposed.

关 键 词：民用 低压直流 电压等级 接地方式 电击防护 IT接地系统 

分 类 号：TM71[电气工程—电力系统及自动化]