苏州轨道交通5 号线正线采用基于直流配电与控制的智能照明系统，用直流为LED 灯具供电。阐述采用直流供电的背景原因及应用方案，将高频开关可控整流电源模块作为直流电源，选用IT 接地系统。根据整流电源模块的输出特性，制定一种基于曼彻斯特编码规则的调光协议，通过直流低频载波通信方式进行指令传输，对灯具进行控制。提出一种以小容量整流电源模块为电源的配电系统短路故障保护方式。通过分析直流电对线缆绝 缘空间电荷的影响，表明低压直流配电选用常规交流线缆产品可满足线缆绝缘安全的要求。在地面站阳澄湖南站的屋顶设置一套小容量分布式光伏发电系统，将直流并网至车站直流照明微电网，实现多端口再生能源接入系统应用。苏州地铁5 号线已于2021 年6 月通车运行，目前直流照明系统运行平稳。

The main line of Suzhou Rail Transit Line 5 employs an intelligent lighting system based on direct current (DC) power distribution and control, with DC supplying power to light-emitting diode (LED) lamps. This study describes the background reasons and application scheme for selecting a DC power supply. A high-frequency switch-controllable rectifier power supply module was used as the DC power supply, and an IT grounding system was selected for the system. A dimming protocol based on Manchester coding rules was developed according to the output characteristics of the rectifier power module. Commands were transmitted via DC low-frequency carrier communication to control the lamps. A short-circuit fault protection method for a distribution system with a small-capacity rectifier power module was proposed. By analyzing the influence of DC on the space charge of the cable insulation, it was determined that conventional alternating current (AC) cable products for low-voltage DC distribution can satisfy the requirements of cable insulation safety. A small-capacity distributed photovoltaic power generation system was installed on the roof of the Yangcheng Hunan Station, which was connected to the DC lighting microgrid of the station to realize the application of a multi-port renewable energy access system. Suzhou Line 5 commenced operation in June 2021, and, to date, the DC lighting systems have been operating smoothly.

U231