Electric power generation system controlled to reduce perception of operational changes

• US 7,999,405 B2
• Filed: 08/11/2009
• Issued: 08/16/2011
• Est. Priority Date: 11/16/2006
• Status: Active Grant

• Current Assignee: Cummins Power Generation IP, Inc.
• Original Assignee: Cummins Power Generation IP, Inc.
• Inventors: Peterson, Mitchell E.
• Primary Examiner(s): Patel; T C
• Assistant Examiner(s): Mohandesi; Iraj A
• Application Number:
  US12/462,891
• Publication Number:
  US 20090302616A1
• Time in Patent Office: 735 Days
• Field of Search: 290/54, 290/40.C
• US Class Current: 290/40.00C
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2210/20 AC to AC converters
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: F02D 29/06 peculiar to engines driving electric generators
• CPC Class Codes: F02D 31/001 Electric control of rotation speed
• CPC Class Codes: F02D 41/083 taking into account engine load variation, e.g. air-conditionning
• 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 10/72 Electric energy management in electromobility

Abstract

An electric power system includes an engine, a generator driven by the engine, an electrical energy storage device, power control circuitry coupling the generator and storage device together, and a processor coupled to the circuitry. The generator provides variable AC power and the storage device provides variable DC power to the circuitry. The processor executes operating logic to provide control signals to the circuitry to operate the generator at a first speed to provide a first level of AC electricity, increase the DC power provided from the storage device to increase the AC electricity to a second level, increase operating speed of the generator from the first speed to a second speed greater than the first speed, decrease the DC power from the storage device as the operating speed of the generator increases, and limit acceleration of the operating speed to reduce perception of a speed change.

Claims

1. A system, comprising:

an engine;

a variable speed generator mechanically coupled to the engine, the engine being structured to drive the generator to provide variable AC power;

an electrical energy storage device to selectively supply variable DC power;

power control circuitry electrically coupled to the generator and the electrical energy storage device to provide regulated AC electricity; and

a processor operatively coupled to the power control circuitry, the processor executing operating logic to provide control signals to the power control circuitry to;

operate the generator at a first rotational speed to provide the AC electricity at a first level, increase the DC power provided from the electrical energy storage device to increase the AC electricity to a second level in response to an electrical load change, increase operating speed of the generator from the first rotational speed to a second rotational speed greater than the first rotational speed in response to the load change, decrease the DC power from the electrical energy storage device as the operating speed of the generator increases, limit a rate of change of the operating speed of the generator to a first speed change rate, the first speed change rate being less than a second speed change rate of the generator.

2. The system of claim 1, further comprising a vehicle with the engine, the generator, the storage device, the power control circuitry, and the processor installed in the vehicle to provide an electric power generation system, and means for controlling the operating speed of the generator by changing speed of the engine.

3. The system of claim 1, further comprising multiple air conditioners installed in the vehicle, the electric power generation system being electrically coupled to the one or more air conditioners to provide the regulated AC electricity thereto, the operating logic being responsive to a power transient caused by activating the multiple air conditioners to provide at least one further control signal to the power control circuitry to accelerate the generator at the second speed change rate.

4. The system of claim 1, wherein the power control circuitry includes a variable voltage DC bus electrically coupled to the generator and the storage device.

5. The system of claim 3, wherein the power control circuitry includes:

a rectifier electrically connected between the generator and the DC bus;

an inverter electrically connected to the DC bus to convert variable voltage power on the DC bus to an AC form; and

a DC-to-DC converter electrically connected between the storage device and the DC bus.

6. The system of claim 1, wherein the power control circuitry includes means for selectively enabling and disabling charging of the storage device with the generator.