不同接地型式低压直流供电系统的电击防护性能理论分析

节能环保的新型低压直流供电系统在民用建筑等常规领域具有巨大的应用潜能与优势，但目前尚未有完善的规范指导其在实际中的应用以保证电气安全。电击防护性能是低压供电系统电气安全的重要衡量指标，但直流电的电击效应与交流电有着本质的差异。结合国际标准IEC60479-1，并参考已有交流系统的分析方法，基于理想直流源模型，对低压直流供电系统TT、IT、TN接地型式的电击防护性能进行了详细的理论分析；对比了直流750、400、300、220 V与交流220 V电压等级下，不同接地型式的电击防护性能，论证了负极接地的TT、TN直流供电系统的电击防护性能相较传统交流系统具有明显优势，并给出了相应的能满足安全条件的电压等级，为低压直流供电系统在民用建筑领域的推广及相关规范的制订提供了参考依据。

Theoretical analysis on the protection properties against electric shock of low voltage DC distribution system with different grounding types

The low voltage direct current(LVDC)distribution system has great potential and advantage to be applied to conventional areas, such as residential house, due to its characteristics of energy conservation and being eco-friendly, but there is no existing standard specifications to guide its application in practice to ensure the electrical safety of this system. The protection against electric shock is a key indicator of electric safety, but the effect of electric shocks on AC and DC are different. Refer to the international standard IEC60479-1 and analytical method in AC system, the protection against electric shock between DC 750, 400, 300, 220 V and AC 220 V systems are compared and analyzed based on ideal DC source model. It demonstrates that the negative grounded TT & TN DC distribution system has significant advantages over the traditional AC system, and the safety voltages are given, which could be a reference to develop the normative guidance for the application of LVDC in practical application.