A Probe into Design of Shore Power Supplying for Ports & Docks

Abstract Features of marine power supplying system are presented briefly. Based on anaylysis of current power consumption situation of shore power TN system guarantee marine power IT system，that it is TT system in nature is pointed out. The power-frequeny temporary over - voltage generated in four cases is chief culprit resulting in some fault with unknown cause. In design of shore power system importance shall be paid to protection aginst power-frequency temporaay over-voltage, IT system shall be used for power supplying, shipboard cables shall be designed as per 0 ?郾 6 / 1 kV, and step - down transformer, 380 / 220 V, shall be installed for single- phase equipments, in port lighting，safety protection，controlling etc., power supplying.   

Key words　Shore power supplying system Marine power supplying system Earthing type of low - voltage distribution system IT system TN system Power-frequency temporaay over - voltage

摘　要　介绍了船舶供电系统的特点，通过对岸电 TN 系统保障船电 IT 系统用电现状分析，指出其实质是 TT 系统，四种情形产生的暂时工频过电压是一些不明原因事故的罪魁祸首，港口码头岸电设计应重视暂时工频过电压的防护，并采用 IT 系统供电，船用电缆应按 0 ?郾 6 / 1 kV 设计，设置 380 / 220 V 降压变压器为港区照明、安防、控制等单相设备供电。

关键词 岸电 船电 低压配电系统的接地形式 IT 系统 TN 系统 工频暂时过电压