Field boost arrangement for separately excited D-C traction motors of a vehicle propulsion system
AssigneeGeneral Electric Company
InventorsNorman Kingston Dickerson, Barry Jay Turley
Life of this patent
Estimating the term…
Abstract
An electrical propulsion control system for self-propelled traction vehicles having an electric generator supplying energy to separately excited traction motors, each motor field being normally excited with a substantially constant field excitation providing magnetic saturation such that motor load variations produce minimal changes in back emf, and means for equally boosting the excitation of each motor field responsive to the largest one of the individual motor armature currents exceeding a predetermined magnitude which is greater than the maximum attainable armature current during dynamic retarding operation.
Claims11
In a propulsion system for traction vehicles using separately excited traction motor means comprising an armature and field winding means and wherein an electrical source provides to said armature an armature current whose magnitude can vary, means for supplying excitation to said field winding means comprising:
- a. first field means to supply a substantially constant predetermined field excitation under normal operating conditions, said field excitation being of adequate magnitude such that the traction motor means is magnetically saturated so that variation of traction motor load produces only a small variation in back electromotive force;
- b. boost field means for supplying additional boost field excitation to increase the torque of said traction motor means;
- c. detecting means for sensing the magnitude of motor armature current;
- and
- d. control means for activating said boost field excitation means solely responsive to said sensed magnitude of armature current exceeding a reference level corresponding to a predetermined high magnitude of armature current.
In a propulsion system for traction vehicles utilizing a plurality of separately excited traction motors each comprising an armature and field winding means and wherein an electrical source provides to the armature of each of said motors an armature current whose magnitude can vary, means for supplying excitation to said field winding means comprising:
- a. first field means to supply to the field winding means of each of said traction motors a substantially constant and equal field excitation;
- b. detecting means for detecting the magnitude of the greatest one of the armature currents of said traction motors;
- and
- c. boost field means responsive to said detecting means for supplying to the field winding means of all of said traction motors equal and additional increments of field excitation to increase the torque of said traction motors, the magnitude of said increments being determined by the magnitude of said greatest one of said armature currents.
Dependencies are inferred from the claim text.