Management of an electric power generation and storage system

• US 7,880,331 B2
• Filed: 06/01/2007
• Issued: 02/01/2011
• Est. Priority Date: 12/29/2006
• Status: Active Grant

• Current Assignee: Cummins Power Generation IP, Inc.
• Original Assignee: Cummins Power Generation IP, Inc.
• Inventors: Bax, Randall, Peterson, Mitchell E.
• Primary Examiner(s): Fureman; Jared J
• Assistant Examiner(s): AMAYA, CARLOS DAVID
• Application Number:
  US11/809,751
• Publication Number:
  US 20080157593A1
• Time in Patent Office: 1,341 Days
• Field of Search: 307/10.1, 307/18, 307/23, 307 44- 47, 320/134, 322/25
• US Class Current: 307/46
• CPC Class Codes: B60L 50/61 by batteries charged by engine-driven generators, e.g. series hybrid electric vehicles
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02P 2201/09 Boost converter, i.e. DC-DC step up converter increasing the voltage between the supply and the inverter driving the motor general aspects of plural converters in cascade H02M
• 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

In one technique of the present invention, DC electric power from a DC bus is inverted to provide AC electricity to one or more electrical loads, and AC power from a variable speed generator is rectified to provide a first variable amount of electric power to the DC bus. This technique also includes determining power applied to the electrical loads, and dynamically controlling the amount of power supplied from the generator and an electrical energy storage device in response to the power applied to the loads.

Claims

1. A method, comprising:

inverting DC electric power from a DC bus to provide AC electricity to one or more electrical loads;

rectifying AC power output from a variable speed generator to provide a variable amount of electric power to the DC bus;

measuring AC electric power provided to the one or more electrical loads;

determining a power control reference that changes with variation of a difference between the AC electric power and capacity of the generator to provide power to the DC bus;

adjusting DC electric power output from an electrical energy storage device to the DC bus in response to change in the power control reference;

decreasing the DC electric power output of the storage device during the adjusting of the DC electric power output;

increasing rotational speed of the generator during the adjusting of the DC electric power output from the storage device; and

during the increasing of the rotational speed, limiting the rate of change of the rotational speed to no more than a predefined level that is less than an available maximum rate of change.

2. The method of claim 1, which includes carrying a system including the generator, the DC bus, the storage device, and the one or more electrical loads with a vehicle.

3. The method of claim 1, which includes:

disabling the DC electric power output from the storage device; and

charging the storage device with electricity from the generator after the disabling of the DC electric power output.

4. The method of claim 1, which includes:

detecting a power transient; and

accelerating the rotational speed of the generator at a higher level than the predefined level in response to the power transient.

5. The method of claim 1, which includes allowing voltage on the DC bus to vary between a minimum nonzero voltage and a maximum nonzero voltage while simultaneously providing the AC electric power output from the generator and the DC electric power output from the storage device to power the one or more loads, a difference between the minimum nonzero voltage being 75% or less of the maximum nonzero voltage.

6. The method of claim 1, which includes controlling rotational speed of the generator as a function of the adjusting DC electric power output.

7. A method, comprising:

inverting DC electric power from a DC bus to provide AC electricity to one or more electrical loads;

rectifying AC power from a variable speed generator to provide a first variable amount of electric power to the DC bus;

detecting voltage and current applied to the one or more electrical loads;

determining a power control reference as a function of the voltage and the current;

in response to the power control reference, regulating DC power from an electrical energy storage device to provide a second variable amount of electric power to the DC bus;

decreasing the DC power from the storage device during the regulating;

increasing rotational speed of the generator during the decreasing of the DC power; and

during the increasing of the rotational speed, limiting the rate of change of the rotational speed to no more than 50 rpm per second.

8. The method of claim 7, which includes carrying a system including the generator, the DC bus, the storage device, and the one or more electrical loads with a vehicle, the one or more electrical loads including an air conditioner for a living space inside the vehicle.

9. The method of claim 7, which includes:

detecting a power transient; and

accelerating the rotational speed of the generator at a higher level than the predefined level in response to the power transient.

10. The method of claim 7, which includes permitting voltage on the DC bus to vary between a minimum nonzero voltage and a maximum nonzero voltage while simultaneously providing the AC power from the generator and the DC power from the storage device to power the one or more loads, a difference between the minimum nonzero voltage being 75% or less of the maximum nonzero voltage.

11. An apparatus, comprising:

a variable speed generator;

an electrical energy storage device;

a DC bus coupled to the variable speed generator and the electrical energy storage device;

means for inverting DC electric power from the DC bus to provide AC electricity to one or more electrical loads;

means for rectifying AC power output from the variable speed generator to provide a variable amount of electric power to the DC bus;

means for measuring AC electric power provided to the one or more electrical loads;

means for determining a power control reference that changes with difference between the AC electric power and capacity of the generator to provide power to the DC bus;

means for adjusting DC electric power output from the electrical energy storage device to the DC bus in response to change in the power control reference;

means for decreasing the DC electric power output of the storage device during the adjusting of the DC electric power output;

means for increasing rotational speed of the generator during the adjusting of the DC electric power output from the storage device; and

means for limiting the rate of change of the rotational speed to no more than a predefined level that is less than an available maximum rate of change during the increasing of the rotational speed.