Locomotive wheel slip control and method

• US 6,634,303 B1
• Filed: 06/11/2002
• Issued: 10/21/2003
• Est. Priority Date: 06/11/2002
• Status: Expired due to Term

• Current Assignee: Progress Rail Locomotive Inc. (Caterpillar Incorporated)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Kral, John Franklin, Madsen, John Ernst
• Primary Examiner(s): Morano, S. Joseph
• Assistant Examiner(s): McCarry, Jr., Robert J.
• Application Number:
  US10/167,032
• Time in Patent Office: 497 Days
• Field of Search: 291/2, 291/22, 291/23, 105/34.1, 105/73, 180/197
• US Class Current: 105/73
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 3/102 of individual wheels

Abstract

A wheel slip control for DC series wound traction motor vehicles such as railway locomotives in which each traction motor drives an axle and connected wheel set. The control utilizes motor field shunting, also known as field weakening, for providing wheel slip control. Each traction motor has its field shunted by a small percentage, such as 10%, during normal motoring operation. In the event that slipping of a wheel set is sensed by the control system, the motor powering the slipping wheel set is controlled by opening the shunting circuit, causing the motor'"'"'s armature current and power to be dramatically reduced, thus stopping the wheel slip and allowing the shunting of the fields to be reapplied. This permits the continuous application of a higher aggregate amount of power over previous wheel slip correction methods and apparatus.

Claims

1. Apparatus for wheel slip control of a vehicle having a DC power source electrically connected to a plurality of DC traction motors, each having a field winding and an armature connected in series, the armature being mechanically connected for directly driving at least one drive wheel of the vehicle, the apparatus comprising:

a shunting resistor connectable in a shunting circuit in parallel with the field winding of each of the traction motors;

a switch in each shunting circuit and openable to prevent shunt current flow through the resistor of the respective circuit; and

a wheel slip control operative to detect excessive speed of any traction motor armature and associated wheel, indicating a wheel slip, and to open the switch, disconnecting the shunting resistor and decreasing current through the associated armature, thereby reducing the armature speed to stop the wheel slip.

2. Apparatus as in claim 1 wherein said vehicle is a diesel railway locomotive in which each traction motor drives an axle mounted on and driving a pair of wheels.

3. Apparatus as in claim 1 wherein the switch is an electrical contactor.

4. Apparatus as in claim 1 wherein the switch is one of a gated transistor and a thyristor.

5. Apparatus as in claim 1 wherein the DC power source is an engine-driven generator.

6. A method for controlling wheel slip in a vehicle having an engine driving a generator electrically connected to a plurality of DC traction motors, each having a field winding and an armature connected in series, the armature being mechanically connected for directly driving at least one drive wheel of the vehicle, the method comprising:

providing at least one shunting resistor connectable in a shunting circuit in parallel with the field winding of each of the traction motors;

providing a switch in each shunting circuit and openable to prevent shunt current flow through the resistor of the respective circuit; and

providing a wheel slip control operative to detect excessive speed of any traction motor armature and associated wheel, indicating a wheel slip, and to open the switch, disconnecting the shunting resistor and decreasing current through the associated armature, thereby reducing the armature speed to stop the wheel slip.

7. A method as in claim 6 including varying the amount of shunting of the field current to vary the control of wheel slip.