海工中压电力系统接地方式的选择与设计

Earthing Method Selection and Design for Offshore Medium Voltage Power System

对电力系统几种常用的接地方式进行分析比较,得出海工中压电力系统最适合中性点经高电阻接地的结论。在介绍分析高电阻接地的主要连接方式和接地故障电流电路模型的基础上,阐述接地设备参数选取的计算方法与原则。并结合实例,演示了单相接地故障电流和接地电阻/变压器参数计算及接地保护装置参数设定的全过程,为大型海洋工程和船舶中压系统接地方案的选择、系统设计和实际应用提供了较为全面的理论依据和有益参考。

By analyzing and comparing several common neutral earthing methods of power system, the conclusion comes out that the neutral earthing through a high resistance is most suitable for offshore medium voltage power system. The calculation formula and sizing principle for the earthing resistor and transformer is then explained, after the brief introduction of the implementation methods and electrical circuit model of earth fault current for high resistance earthing method. Finally one example given to demonstrate the calculation of earth fault current and the principle of determining the parameters of earth fault protective device. The article will present full theoretical basis and helpful guide to solution selection, relevant design and practical application regarding the neutral earthing for offshore medium voltage power system.