Use of traction inverter for supplying power for non-traction applications

• US 6,023,137 A
• Filed: 08/14/1998
• Issued: 02/08/2000
• Est. Priority Date: 10/01/1997
• Status: Expired due to Term

• Current Assignee: GE Global Sourcing LLC (Westinghouse Air Brake Technologies Corporation)
• Original Assignee: General Electric Company
• Inventors: Griebel, Ronald Francis, Kumar, Ajith Kuttannair
• Primary Examiner(s): IP, SHIK LUEN PAUL
• Application Number:
  US09/134,117
• Time in Patent Office: 543 Days
• Field of Search: 318/138, 318/139, 318/254, 318/712, 318/719, 318/723, 318/701, 318/721, 322/20, 322/28, 322/36, 123/198 D, 123/352, 123/357, 123/478, 123/481, 123/198 F, 123/41.13, 363/21, 364/424.01
• US Class Current: 318/400.27
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2220/14 Synchronous machines
• CPC Class Codes: B60L 3/003 relating to inverters
• CPC Class Codes: B60L 3/0092 with use of redundant elements for safety purposes
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: F01M 2001/123 using two or more pumps
• CPC Class Codes: F01M 5/025 by prelubricating, e.g. using an accumulator
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors

Abstract

A method and apparatus for cranking of an internal combustion engine in an AC electric traction motor propelled vehicle using inverters normally coupled to supply power to each of a plurality of AC motors. The inverters have DC input terminals connected between a relatively positive DC bus and a relatively negative DC bus and the DC buses are connected to DC output terminals of a rectifier. The rectifier has AC input terminals connected to stator terminals of a synchronous generator. The generator includes a field winding and a rotor connected in driving relationship to a crank shaft of the engine. The vehicle further includes switching apparatus for selectively connecting a battery to the positive and negative DC buses and for disconnecting at least one of the inverters from the AC motor and connecting the at least one of the inverters to supply power to the generator such that the at least one of the inverters is operable to energize the generator whereby the generator operates in a motoring mode to rotate the engine crank shaft to start the engine. Another of the inverters is separately connectable to a pre-lube pump motor for effecting lubrication of the engine prior to starting the engine. After lubricating and starting of the engine, the switch reconnects the inverters to supply AC electric power to respective traction motors of the vehicle.

Claims

1. In a locomotive having a plurality of alternating current (AC) electric traction motors each coupled in driving relationship to a respective one of a plurality of driven wheels of the locomotive, each of the traction motors having excitation windings coupled in circuit with a corresponding one of a plurality of power inverters, the inverters each having a plurality of controllable electric valves for supplying controlled frequency electric power to the corresponding motor by inversion of direct current (DC) power supplied to input terminals of the inverter, the DC power being obtained from rectification of AC power generated at stator winding terminals of an alternator having a rotor connected to be rotatably driven by an internal combustion engine, the locomotive including a battery for supplying power for cranking the engine and for energizing a pre-lube pump motor for lubricating the engine prior to cranking, the improvement comprising:

first switching means for coupling the input terminals of at least one of said plurality of inverters in electric circuit arrangement for receiving DC electric power from the battery;

second switching means selectively conditionable for coupling the output terminals of at least one of said plurality of inverters to respective ones of the stator winding terminals of the alternator and to excitation windings of the corresponding AC electric traction motor, said second switching means being operable to selectively switch said power inverters into circuit arrangement with the alternator stator windings for supplying power to drive the alternator in a motoring mode for cranking the engine;

third switching means selectively conditionable for coupling the output terminals of another of said plurality of inverters to respective ones of the input terminals of the pre-lube pump motor;

control means for first energizing the electric valves of said another of said inverters for energizing said pump motor and lubricating said engine, for subsequently de-energizing said another inverters and thereafter energizing the electric valves of said at least one of said plurality of inverters to supply variable frequency excitation to the alternator stator windings for effecting rotation of the rotor thereof and concurrent rotation of the drive shaft of the engine for cranking of the engine when said second means is conditioned for selectively coupling the inverters to the stator winding terminals of the alternator; and

each of said first, second and third switching means being operative to connect output terminals of said at least one and another of said inverters to corresponding input terminals of respective ones of said traction motors.

2. The improvement of claim 1 wherein the electric valves of the inverter comprise gate turn-off switching devices.

3. The improvement of claim 1 wherein said first, second and third switching means comprises an electrically operated multigang switch.

4. The improvement of claim 1 wherein the alternator includes a field winding and said first switching means is operable for coupling said alternator field winding in series electrical circuit with said at least one power inverter and the battery.

5. The improvement of claim 4 and including means coupled in circuit with said alternator field winding for adjusting current in said alternator field winding.

6. The improvement of claim 4 wherein said second switching means is operable in a first cranking mode for coupling a first one of said inverters into power supplying arrangement with said stator windings of said alternator and operable in a second cranking mode for coupling a second one of said inverters into power supply arrangement with said stator windings of said alternator.

7. A method for cranking and operating an internal combustion engine in a locomotive having a plurality of alternating current (AC) electric traction motors each coupled in driving relationship to a respective one of a plurality of driven wheels of the locomotive, each of the traction motors having excitation windings coupled in circuit with a corresponding one of a plurality of power inverters, each AC motor being powered from the corresponding inverter, the inverters each having DC input terminals connected between relatively positive and negative DC buses, the DC buses being connected to DC output terminals of a rectifier, the rectifier having AC input terminals connected to stator terminals of a synchronous generator, the generator including a field winding and a rotor connected in driving relationship to a crank shaft of the engine, the vehicle further including a battery selectively connectable to the positive and negative DC buses and a pre-lube pump motor for pumping lubricant into the engine prior to cranking, the method comprising the steps of:

disconnecting one of the inverters from the corresponding one of the AC motors and selectively connecting the one of the inverters to supply power to the pre-lube pump motor;

disconnecting another of the inverters from the corresponding one of the AC motors and selectively connecting the another of the inverters to supply power to the generator by connecting the field winding of the generator into a series circuit with the battery and the DC input terminals of the another of the inverters; and

operating the one and another of the inverters in sequence to initially lubricate the engine and thereafter to energize the generator whereby the generator operates in a motoring mode to rotate the engine crank shaft to start the engine.

8. The method of claim 7 wherein the step of connecting the field winding includes the steps of connecting a positive voltage terminal of the battery to the positive DC bus, connecting one terminal of the generator field winding to a negative voltage terminal of the battery and connecting another terminal of the field winding to the negative voltage bus with the battery negative voltage terminal disconnected from the negative voltage bus.