Electric power generation system with multiple alternators driven by a common prime mover

• US 7,956,584 B2
• Filed: 06/01/2007
• Issued: 06/07/2011
• Est. Priority Date: 12/29/2006
• Status: Active Grant

• Current Assignee: Cummins Power Generation IP, Inc. (Cummins Incorporated)
• Original Assignee: Cummins Power Generation IP, Inc. (Cummins Incorporated)
• Inventors: Kunin, Sergey, Peterson, Mitchell E.
• Primary Examiner(s): Gonzalez; Julio Cesar
• Application Number:
  US11/809,768
• Publication Number:
  US 20080157594A1
• Time in Patent Office: 1,467 Days
• Field of Search: 290/40.C, 290/4.A, 290/4.C, 290/4.R, 322/44, 322/59, 310/112, 310/114
• US Class Current: 322/44
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 58/30 for monitoring or controlling fuel cells
• CPC Class Codes: B60L 58/33 by cooling
• CPC Class Codes: H02P 2101/45 for motor vehicles, e.g. car alternators
• CPC Class Codes: H02P 9/04 Control effected upon non-electric prime mover and dependent upon electric output value of the generator
• CPC Class Codes: H02P 9/307 more than one voltage output
• CPC Class Codes: H02P 9/48 Arrangements for obtaining a constant output value at varying speed of the generator, e.g. on vehicle H02P9/04 - H02P9/46 take precedence
• 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
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

An apparatus includes a vehicular electric power generation system comprising a variable speed internal combustion engine, a first variable speed electric power generator driven by the engine, a second variable speed electric power generator driven by the engine, a first inverter to receive electric power from the first generator a provide a first controlled electric output, a second inverter to receive electric power from the second generator and provide a second controlled electric output, and a controller coupled to the engine. The controller is responsive to variation in electrical loading of the first inverter and the second inverter and a degree of electrical load imbalance between the first inverter and second inverter to provide one or more engine control signals. The engine is responsive to the one more engine control signals to change rotational operating speed to adjust for the variation in electrical loading and the degree of electrical load imbalance.

Claims

1. An apparatus, comprising:

an internal combustion engine;

a first variable speed generator driven by the engine;

a second variable speed generator driven by the engine;

a first inverter to convert variable electric power from the first variable speed generator to provide a first controlled AC voltage at a first electrical output node;

a second inverter to convert variable electric power from the second variable speed generator to provide a second controlled AC voltage at a second electrical output node, the first inverter and the second inverter being electrically connected together with a common electrical node to provide a third controlled AC voltage across the first output node and the second output node greater than each of the first controlled AC voltage and the second controlled AC voltage; and

means for controlling the first inverter and the second inverter to provide a first power output waveform at the first electrical output node and a second power output waveform at the second electrical output node, the first power output waveform being approximately 180 degrees out of phase with the second power output waveform and the common node corresponding to a neutral line.

2. The apparatus of claim 1, further comprising means for charging an electrical energy storage device with one or more of the first variable speed generator and the second variable speed general and means for boosting power output through one or more of the first inverter and the second inverter with the electrical energy storage device.

3. The apparatus of claim 1, further including another engine to provide propulsion for the motor coach, a trailer, a camper, or a watercraft.

4. The apparatus of claim 1, wherein the first generator includes a first armature and the second generator includes a second armature, the first armature and the second armature each being fixed to a common shaft driven by the internal combustion engine, and being provided as different three-phase AC outputs of an alternator winding.

5. An apparatus, comprising:

a first variable speed electric generator power;

a second variable speed electric generator power;

a first rectifier connected to the first variable speed generator, a first DC bus connected to the first rectifier, and a first inverter connected to the first DC bus;

a second rectifier connected to the second variable speed generator, a second DC bus connected to the second rectifier, and a second inverter connected to the second DC bus; and

at least one energy storage device electrically coupled to at least one of the first DC bus and the second DC bus,

the apparatus, further comprising means for controlling the first inverter and the second inverter to provide a first power output waveform at the first electrical output node and a second power output waveform at the second electrical output node, the first power output waveform being approximately 180 degrees out of phase with the second power output waveform and the common node corresponding to a neutral line.

6. The apparatus of claim 5, further comprising a vehicle with a first engine for propulsion and a second engine to drive both the first generator and the second generator.

7. The apparatus of claim 6, wherein the vehicle is one of a motor coach, a trailer, a camper, and a watercraft.

8. The apparatus of claim 5, wherein the first generator includes a first armature and the second generator includes a second armature, the first armature and the second armature each being fixed to a common shaft driven by the internal combustion engine.

9. A method, comprising:

with a vehicle, carrying a first variable speed electric power generator, a second variable speed electric power generator, a first inverter coupled to the first generator, and a second inverter coupled to the second generator,

driving the first variable speed electrical generator and the second variable speed electrical generator;

controlling the first inverter and the second inverter to provide a first electric power output with a first controlled AC voltage across one of the first inverter and the second inverter, and a second electric power output with a second controlled AC voltage across both of the first inverter and the second inverter, the second AC voltage being greater than the first AC voltage;

boosting at least one of the first electric power output and the second electric power output from an electrical energy storage device; and

charging the electrical energy storage device with at least one of the first generator and the second generator.

10. A method, comprising:

with a vehicle, carrying a first variable speed electric power generator, a second variable speed electric power generator, a first inverter coupled to the first generator, and a second inverter coupled to the second generator;

driving the first variable speed electrical generator and the second variable speed electrical generator;

controlling the first inverter and the second inverter to provide a first electric power output with a first controlled AC voltage across one of the first inverter and the second inverter, and a second electric power output with a second controlled AC voltage across both of the first inverter and the second inverter, the second AC voltage being greater than the first AC voltage,

wherein the first inverter and the second inverter are coupled together with a common neutral line, the first AC voltage is provided at a first output node of the first inverter, the second inverter provides a third AC voltage at a second output node, the third AC voltage is approximately 180 degrees out of phase with the first AC voltage, and the second AC voltage is provided across the first output node and the second output node.

11. A method, comprising:

with a vehicle, carrying a first variable speed electric power generator, a second variable speed electric power generator, a first inverter coupled to the first generator, and a second inverter coupled to the second generator,

driving the first variable speed electrical generator and the second variable speed electrical generator;

controlling the first inverter and the second inverter to provide a first electric power output with a first controlled AC voltage across one of the first inverter and the second inverter, and a second electric power output with a second controlled AC voltage across both of the first inverter and the second inverter, the second AC voltage being greater than the first AC voltage,

wherein the driving includes providing mechanical power for both the first generator and the second generator with a variable speed internal combustion engine and the controlling includes accounting for a load imbalance between the first inverter and the second inverter and responding to a electrical load changes by adjusting speed of the engine.