×

Electric vehicle traction motor control

  • US 4,172,233 A
  • Filed: 03/07/1978
  • Issued: 10/23/1979
  • Est. Priority Date: 03/09/1977
  • Status: Expired due to Term
First Claim
Patent Images

1. An electric vehicle traction motor control circuit comprising a main thyristor in series with the motor armature between a pair of supply rails, a second thyristor arranged on firing to divert current from the main thyristor into a commutating capacitor, a third thyristor connected in series with an inductor across the commutating capacitor and arranged on firing to reverse the voltage on the commutating capacitor, driver operable control means for determining upper and lower motor current limits, means sensitive to the magnitude of a voltage stored on the commutating capacitor for downwardly adjusting said motor current limits independently of said driver operable control means if said stored voltage is too low to ensure commutation, first firing control means for firing the main thyristor when the actual motor current is less than said lower limit, second firing control means for firing the second thyristor when the actual motor current exceeds the upper limit and third firing control means for the third thyristor.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×