1　问题的提出现代化的港口要求岸边配电设备有很高的安全可靠性,同时操作维护方便,外形美观。港口有时要多台门机同时作业,尤其是两台门机同时在同一舱口作业,以充分利用码头的有限场地,适应船舱的空载作业、满载作业及地面车辆的通行。根据港口供电技术规范的要求,码头前 1 The issue of the proposed modern port requirements shore power distribution equipment has a high safety and reliability, and easy operation and maintenance, beautiful appearance. Ports sometimes require simultaneous operation of multiple door machines. In particular, two door machines operate simultaneously in the same hatch to fully utilize the limited space of the wharf, to accommodate the no-load operation of the cabins, full load operation and the passage of ground vehicles. According to the port power supply technical specifications, front of the terminal