Energy storage system for peak-shaving of drilling rig power usage

• US 8,446,037 B2
• Filed: 04/09/2010
• Issued: 05/21/2013
• Est. Priority Date: 12/04/2009
• Status: Active Grant

• Current Assignee: Nabors Drillling Technologies USA, Inc.
• Original Assignee: Kevin R. Williams
• Inventors: Williams, Kevin R.
• Primary Examiner(s): KAPLAN, HAL IRA
• Application Number:
  US12/757,234
• Publication Number:
  US 20110148209A1
• Time in Patent Office: 1,138 Days
• Field of Search: None
• US Class Current: 307/23
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 7/34 Parallel operation in networks using both storage and other dc sources, e.g. providing buffering H02J7/14 takes precedence

Abstract

An energy storage means for a drilling rig has a source of power, an AC bus connected to the source of power, a DC bus, a load connected to the DC bus, a rectifier connected to the AC bus and to the DC bus for converting AC power from the source of power to DC power to the load, and an energy storage system connected to the DC bus. The energy storage system can be batteries, capacitors or combinations thereof. A diode is connected between the energy storage means and the DC bus so as to supply power to the load when the DC voltage is less than a DC source voltage. The energy storage system has a nominal voltage slightly lower than a voltage of a AC-to-DC conversion by the rectifier.

Claims

1. An energy storage system comprising:

a source of power;

an AC bus connected to said source of power;

a DC bus having a DC source voltage;

a load connected to said DC bus;

a rectifying means connected to said AC bus and to said DC bus, said rectifying means for converting AC power from said source of power to DC power to said load;

an energy storing means connected to said DC bus, said energy storage means for supplying energy to said load;

an energy supplying means connected between said energy storing means and said DC bus, said energy supplying means for supplying energy to said load when a DC voltage to said load is less than the DC source voltage;

a charging means connected to said AC bus, said charging means for supplying power to said energy storing means; and

a blocking diode connected between said energy storing means and said DC bus, said charging means connected between said blocking diode and said energy storing means.

2. The energy storage system of claim 1, said energy storing means selected from the group of batteries, capacitors, and paralleled-series of batteries and capacitors.

3. The energy storage system of claim 1, said energy storing means having a nominal voltage slightly lower than an voltage of said rectifying means.

4. The energy storage system of claim 1, further comprising:

a charging means connected to said DC bus and to said energy storing means, said charging means for supplying power to said energy storing means.

5. An energy storage system for a drilling rig comprising:

an engine/generator suitable for producing AC power;

a rectifying means electrically interconnected to said engine/generator for convening, the AC power to DC power;

a DC bus electrically connected to said rectifying means, said DC bus having a DC source voltage;

a load connected to said DC bus;

an energy storing means connected to said DC bus, said energy storing means for supplying power to said load when a DC voltage to said load at, said DC bus is less than the DC source voltage;

, and

a diode connected between said energy storing means and said DC bus, said diode suitable for allowing power to pass from said energy storing means to said load when said DC voltage is less than said DC source voltage.

6. The energy storage system of claim 5, said energy storing means selected from the group consisting of batteries, capacitors, and paralleled-series of batteries and capacitors.

7. The energy storage system of claim 5, further comprising:

an AC bus connected to said engine/generator and to said rectifying means.

8. The energy storage system of claim 7, further comprising:

a charging means connected to said AC bus, said charging means for supplying power to said energy storing means.