01735967

Monograph

http://www.trb.org/Main/Blurbs/180403.aspx

Improving the reliability of railway electric systems and preventing electrical outages due to insulator flashover and insulation failure is difficult because of aging infrastructure and the lack of continuous monitoring of the state of the systems. This report documents low-level leakage current detection methods using two approaches. The first approach involves injecting a high frequency signal into a segment of the power line nonintrusively and determining the high frequency impedance of the selected line segment. Segmentation of the line is achieved by applying a virtual blocker at each end of the chosen segment. The high frequency impedance of that segment is thus linked to the condition of the cable and the level of the leakage current in the segment. The second approach measures the radio frequency (RF) emissions from the power network and relates the condition of the network to the frequency content of those emissions. This guidebook provides specifications for the sensors for the two approaches as well as outlines their capabilities and appropriate operating conditions. The sensors developed can be classified into two categories: (1) nonintrusive injection-based and (2) RF emission-based sensors. The frequency, voltage, and current limitations are specified for the injection-based sensors. The data processing and linkage to failures along with the frequency of operation are provided for the RF emission-based sensors.

Project D-17

English

63p

2020

TCRP Research Report

9780309481649

Digital/other

Appendices; Bibliography; Figures; Photos; References; Tables

Direct current; Electric insulating materials; Electric trains; Fault monitoring; Insulators (Electricity); Leakage; Radio frequency; Sensors

Energy; Public Transportation; Safety and Human Factors

TRIS, TRB, ATRI

Mar 26 2020 4:09PM