成都轨道交通18号线综合接地方案的优化

Optimization Scheme of Comprehensive Grounding for Chengdu Metro Line 18

成都轨道交通18号线采用AC 25 kV架空接触网供电,其接地系统设计不推荐参照既有铁路线的接地方案。在综合考虑接地电阻、等电位连接、钢轨电位等多个要素后,提出应用于交流牵引供电制式的城市轨道交通综合接地系统。该综合接地系统将上/下行钢轨作为主接地载体,以沿线架设的上/下行牵引网回流线为辅助接地载体,形成等电位综合接地平台。针对该线接地系统原设计方案在工程实施过程中出现的问题,从过分相区的接地优化、正线的接地优化两方面提出了具体的接地优化措施,可为后续交流牵引供电下的市域轨道交通线综合接地网的设计提供参考。

Chengdu metro Line 18 adopts AC 25 kV overhead catenary for power supply,but the grounding scheme of existing railway line is not recommended for Line 18.After comprehensive consideration of various factors such as the grounding resistance,equipotential bonding,rail potential and so on,an integrated grounding system for urban rail transit with AC traction power supply system is proposed.This grounding system takes the up/down rails as the main grounding carrier,and the up/down traction network return line erected along the rail transit line as the auxiliary grounding carrier to form an equipotential integrated grounding platform.In view of problems in the implementation of the original grounding system design for Line 18,specific grounding optimization measures are proposed from two aspects:the grounding optimization of excess phase zone and the grounding optimization of the main track,which can provide a reference for the design of the follow-up integrated grounding network of city railway with AC traction power supply.