铁路信号电缆网络故障在线检测系统设计

实现铁路信号电缆网络在线管理与故障自动诊断，可提高信号电缆的工作可靠性，减少电缆故障的人工排查工作量，提高铁路运营的自动化程度。设计基于同一硬件平台的多种故障检测方法相结合的铁路车站信号电缆网络故障在线检测系统，实现对车站信号电缆网络的实时在线监测和故障自动定位。该系统以DSP＋CPLD模块为核心电路，利用DDS芯片发生任意信号波形，运用新型高速A／D芯片进行采样，通过485总线实现各功能模块之间的通讯。可组成分布式检测网络，利用SSTDR检测技术实现信号电缆的实时在线监测，在线预测电缆低阻故障，再利用TFDR检测技术进行离线故障精确定位和类型判断。

Design of Railway Signal Cable Network Fault On-line Detection System

Railway signal cable network on-line management and automatic fault diagnosis can improve the reliability of signal cable, reduce the cable fault of the manual workload of the investigation, and improve the operation of the railway automation. Described the design of a detection system whose hardware platform can achieve a variety of fault detection methods of cables. The system uses DSP and CPLD circuit as a core module and DDS chip to generate arbitrary waveforms. A new high-speed A/D chip was used for sampling. Distributed detection network can be formed by RS - 485 bus. SSTDR detection technology was used to achieve on-line testing and to predict the occurrences of low resistance short-circuit faults. TFDR detetion technology is used to detect the fault type and precise location.