NTL Record

Title Inductive Interference in Rapid Transit Signaling Systems Volume I: Theory and Background
Record ID 49764
Personal Name
Creator
Holmstrom, F. Ross
Source 43p. in various pagings
Corporate Creator John A. Volpe National Transportation Systems Center (U.S.)
Corporate
Contributor
United States. Urban Mass Transportation Administration
Publisher United States. Urban Mass Transportation Administration
Publication Date 19860501
Language English
Abstract This report describes the mechanism of inductive interference to audio frequency (AF) signaling systems used in rail transit operations, caused by rail transit vehicles with chopper propulsion control. Choppers are switching circuits composed of high-power semiconductor devices, inductors, and capacitors. Chopper-controlled propulsion systems on subway cars can cause inductive interference with AF signaling systems, when time-varying magnetic flux lines emanating from chopper systems on vehicles pass through the rail-axle loops under the cars. When a vehicle passes over points at which track circuit receivers are connected to the rails, inductively generated interfering signals can cause track circuits to malfunction. Observation of such interference led directly to the establishment of the Rail Transit EMI Technical Working Group, under the sponsorship of the Urban Mass Transportation Administration. This report also examines chopper interference generation as well as methods for observing and recording interference signals; develops a physical model for calculating levels of inductive interference; gives selected results of field observations; and discusses methods for alleviating the problem, such as improved track signal detection, frequency-domain coding, and new chopper components that generate less stray flux.
Rosap ID dot:11188
Rosap URL https://rosap.ntl.bts.gov/view/dot/11188
TRT Terms Electromagnetic interference; Inductive interference; Propulsion; Rail transit; Rapid transit; Solid state devices; Test procedures; Vehicle power plants; Audio frequency; Automatic train control; Chopper circuits; Fluxes
General Subjects Inductive EMI; Rail system EMI; EMI measurements; Compatibility; Propulsion systems; Magnetic flux
Classification NTL - PUBLIC TRANSPORTATION - PUBLIC TRANSPORTATION;
NTL - PUBLIC TRANSPORTATION - Rail Transit;
NTL - PUBLIC TRANSPORTATION - Transit Energy and Environment;
NTL - PUBLIC TRANSPORTATION - Transit Safety and Security
Geographical
Coverage
United States
Report Number UMTA-MA-06-0153-85-7; DOT-TSC-UMTA-86-2
Resource type Tech Report
URL https://ntlrepository.blob.core.windows.net/lib/49000/49700/49764/DOT-TSC-UMTA-86-2.pdf
Format PDF
Database NTL Digital Repository