Locomotive excitation and regenerative braking control arrangement

Claim 2

A power control system for the traction motors of an electric locomotive operable to provide power and regenerative braking modes of operation for said motors comprising, a right-of-way source of direct voltage, a plurality of direct current traction motors operable when energized to provide motive power for said locomotive, each traction motor having a field winding, a plurality of series connected drive motors, a generator having a direct voltage output, means mechanically connecting said drive motors and said generator, switching means having a first position for operating said traction motors in a power mode and a second position for operating said traction motors in a regenerative braking mode, said switching means in said first position electrically connecting said series connected drive motors in series with said traction motors across said source of voltage, said switching means in said first position further electrically connecting said traction motors across said generator whereby said traction motors can be supplied current from said generator and from said source of direct voltage through said drive motors, said switching means in said second position electrically connecting the field windings of said traction motors across said generator whereby said generator supplies current to the field windings of said traction motors during said braking mode of operation, said switching means in said second position further electrically connecting one of said plurality of drive motors across said traction motors whereby said traction motors when operating as generators in said braking mode can supply current to said one drive motor, said one drive motor during said braking mode mechanically driving the other drive motors and said generator whereby said other drive motors operate as generators to return power to said source of direct voltage and whereby said generator supplies field current to the field windings of said traction motors, and means for balancing armature current between respective traction motors when they are operating in said braking mode.

Claim 3

A power control system for the traction motors of an electric locomotive operable to provide power and regenerative braking modes of operation for said motors comprising, a right-of-way source of direct voltage, a plurality of direct current traction motors operable when energized to provide motive power for said locomotive, each traction motor having an armature and a field winding, a plurality of series connected drive motors, an alternating current generator, rectifier means connected to said generator having a direct voltage output, means mechanically connecting said drive motors and said generator, switching means having a first position for operating said traction motors in a power mode and a second position for operating said traction motors in a regenerative braking mode, said switching means in said first position electrically connecting said series connected drive motors in series with said traction motors across said source of voltage, said switching means in said first position further electrically connecting said trAction motors across said rectifier means whereby said traction motors can be supplied direct current from said rectifier means and from said source of direct voltage through said drive motors, said switching means in said second position electrically connecting the field windings of said traction motors across said rectifier means whereby said rectifier means supplies current to the field windings of said traction motors during said braking mode of operation, said switching means in said second position further electrically connecting one of said plurality of drive motors across the armatures of said traction motors whereby said traction motors when operating as generators in said braking mode can supply current to said one drive motor, said one drive motor during said braking mode mechanically driving the other drive motors and said generator whereby said other drive motors operate as generators to return power to said source of direct voltage and whereby said generator and rectifier means supplies field current to the field windings of said traction motors, and a plurality of resistors connected respectively in the armature circuits of said traction motors during said braking mode to balance armature current among said traction motors.

Claim 4

A power control system for the traction motors of an electric locomotive operable to provide power and regenerative braking modes of operation for said motors comprising, a right-of-way source of direct voltage, a plurality of direct current traction motors operable when energized to provide motive power for said locomotive, each traction motor having an armature and a field winding, a plurality of series connected drive motors, an alternating current generator, rectifier means connected to said generator having a direct voltage output, means mechanically connecting said drive motors and said generator, switching means having a first position for operating said traction motors in a power mode and a second position for operating said traction motors in a regenerative braking mode, said switching means in said first position electrically connecting said series connected drive motors in series with said traction motors across said source of voltage, said switching means in said first position further electrically connecting said trAction motors across said rectifier means whereby said traction motors can be supplied direct current from said rectifier means and from said source of direct voltage through said drive motors, said switching means in said second position electrically connecting the field windings of said traction motors across said rectifier means whereby said rectifier means supplies current to the field windings of said traction motors during said braking mode of operation, said switching means in said second position further electrically connecting one of said plurality of drive motors across the armatures of said traction motors whereby said traction motors when operating as generators in said braking mode can supply current to said one drive motor, said one drive motor during said braking mode mechanically driving the other drive motors and said generator whereby said other drive motors operate as generators to return power to said source of direct voltage and whereby said generator and rectifier means supplies field current to the field windings of said traction motors, and a plurality of resistors connected respectively in the armature circuits of said traction motors during said braking mode to balance armature current among said traction motors.

Claim 5

A power control system for the traction motors of an electric locomotive operable to provide power and regenerative braking modes of operation for said motors comprising, a right-of-way source of direct voltage, a plurality of direct current traction motors operable when energized to provide motive power for said locomotive, each traction motor having an armature and a field winding, a plurality of series connected drive motors, an alternating current generator, rectifier means connected to said generator having a direct voltage output, means mechanically connecting said drive motors and said generator, and switching means having a first position for operating said traction motors in a power mode and a second position for operating said traction motors in a regenerative braking mode, said switching means in said first position electrically connecting said series connected drive motors in series with said traction motors across said source of voltage with the armature and field of each traction motor connected in series, said switching means in said first position further electrically connecting said traction motors across said rectifier means whereby said traction motors can be supplied current from said rectifier means and from said source of direct voltage through said drive motors, said switching means in said second position electrically connecting the field windings of said traction motors across said rectifier means whereby said rectifier means supplies current to the field windings of said traction motors during said braking mode of operation, said switching means in said second position further electrically connecting one of said plurality of drive motors across said traction motors whereby said traction motors when operating as generators in said braking mode can supply current to said one drive motor, said one drive motor during said braking mode mechanically driving the other drive motors and said generator whereby said other drive motors operate as generators to return power to said source of direct voltage and whereby said generator supplies field current to the field windings of said traction motors, said armature and field of each traction motor be maintained in a series connection during said braking mode whereby current developed in an armature during regeneration passes through a series connected field winding, the sense of said last named current being opposite to that supplied to said field windings by said rectifier means.

Claim 6

A power control system for the traction motors of an electric locomotive operable to provide power and regenerative braking modes of operation for said motors comprising, a right-of-way source of direct voltage, a plurality of direct current traction motors operable when energized to provide motive power for said locomotive, each traction motor having an armature and a field winding, a plurality of series connected drive motors, an alternating current generator, rectifier means connected to said generator having a direct voltage output, means mechanically connecting said drive motors and said generator, and switching means having a first position for operating said traction motors in a power mode and a second position for operating said traction motors in a regenerative braking mode, said switching means in said first position electrically connecting said series connected drive motors in series with said traction motors across said source of voltage with the armature and field of each traction motor connected in series, said switching means in said first position further electrically connecting said traction motors across said rectifier means whereby said traction motors can be supplied current from said rectifier means and from said source of direct voltage through said drive motors, said switching means in said second position electrically connecting the field windings of said traction motors across said rectifier means whereby said rectifier means supplies current to the field windings of said traction motors during said braking mode of operation, said switching means in said second position further electrically connecting one of said plurality of drive motors across said traction motors whereby said traction motors when operating as generators in said braking mode can supply current to said one drive motor, said one drive motor during said braking mode mechanically driving the other drive motors and said generator whereby said other drive motors operate as generators to return power to said source of direct voltage and whereby said generator supplies field current to the field windings of said traction motors, said armature and field of each traction motor be maintained in a series connection during said braking mode whereby current developed in an armature during regeneration passes through a series connected field winding, the sense of said last named current being opposite to that supplied to said field windings by said rectifier means.