A test and analysis program performed on four complete propulsion systems for an urban electric vehicle (EV) is described and results given. A dc series motor and a permanent magnet (PM) motor were tested, each powered by an EV battery pack and controlled by (1) a series/parallel voltage-switching (V-switch) system; and (2) a system using a pulse width modulation, 400 Hz transistorized chopper. Dynamometer tests were first performed, followed by eV performance predictions and data correlating road tests. During dynamometer tests using chopper control; current, voltage, and power were measured on both the battery and motor sides of the chopper, using three types of instrumentation. Conventional dc instruments provided adequate accuracy for eV power and energy measurements, when used on the battery side of the controller. When using the chopper controller, the addition of a small choke inductor improved system efficiency in the lower duty cycle range (some 8% increase at 50% duty cycle) with both types of motors. Overall system efficiency rankings during road tests were: (1) series motor with V-switch; (2) PM motor with V-switch; (3) series motor with chopper; and (4) PM motor with chopper. Chopper control of the eV was smoother and required less driver skill than V-switch control.

  • Corporate Authors:

    Three E Vehicles

    P. O. Box 19409
    San Diego, CA  United States 

    National Aeronautics and Space Administration

    600 Independence Avenue, SW
    Washington, DC  United States  20546
  • Authors:
    • Shipps, P R
  • Publication Date: 1980-5

Media Info

  • Pagination: 88 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00318295
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: NASA-CR-159776 Final Rpt., DOE/NASA/0130-80/1
  • Contract Numbers: DEN3-130, EC-77-A-31-1044
  • Files: TRIS
  • Created Date: Sep 16 1981 12:00AM