Technical Reports

Laboratory and Field Testing of NYCTA Power Frequency Track Circuits

  • 01
  • Feb
  • 1986
AUTHOR: M. D. West, F. R. Holmstrom
OFFICE: RPD
REPORT NUMBER: UMTA-M A-06-0153-85-12
SUBJECT: Signal and Train Control
KEYWORDS: AC Propulsion Control Systems; Electromagnetic Interference; Power Frequency Signaling System
ABSTRACT: This report addresses the possible electromagnetic interference between the electronic AC propulsion control systems and the signaling and train control systems. The potential exists for AC-drive propulsion systems to cause EMI that can adversely affect the operation of NYCTA's power-frequency track circuits. Harmonic components of the variable-frequency propulsion currents generated by the inverters conceivably could leak onto the third rail and then be magnetically coupled to the track circuits. General operating characteristics of the track circuits, test methods, and results are presented in this report. A good qualitative picture of overall NYCTA track circuit susceptibility to EMI was obtained. Each of the thirteen track circuits tested in the lab gave precise and repeatable results. Results obtained from the field tests of three track circuits were more variable, due to variability of conditions; however, results from the field were very similar to those obtained in the lab. The data from these measurements have been provided to the equipment manufacturers involved in the AC propulsion program and to the NYCTA.

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