Local area grid for distributed power

• US 20020036430A1
• Filed: 09/28/2001
• Published: 03/28/2002
• Est. Priority Date: 09/28/2000
• Status: Abandoned Application

• Current Assignee: Youtility Incorporated
• Original Assignee: Youtility Incorporated
• Inventors: Wen, Jian, Welches, Richard S., Griessel, Richard E.
• Application Number:
  US09/966,241
• Publication Number:
  US 20020036430A1
• Time in Patent Office: Days
• US Class Current: 307/18
• CPC Class Codes: F02G 1/043 the engine being operated by expansion and contraction of a mass of working gas which is heated and cooled in one of a plurality of constantly communicating expansible chambers, e.g. Stirling cycle type engines
• CPC Class Codes: F02G 2254/11 Catalytic burners
• CPC Class Codes: H02J 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers

Abstract

The invention in the simplest form is a system for managing distributed power sources connected to a power grid. The present invention manages power flow to/from the power grid whether for a stand-alone power sourece or for local area utility grid or microgrid. When two or more power sources are interconnected by the local grid, each source has a power conditioning unit and a circuit breaker manager for controlling and regulating the electric flow to/from the grid. The individual power sources are able to independently draw power from the grid when required without extensive master control schemes. In a preferred embodiment the power sources are reformer equipped fuel cells and the heat from the fuel cell is used as a heat source for efficiency.

Claims

1. A distributed power system for a utility grid, comprising:

a distributed power source;

a temperature measuring device;

a power conditioning unit, wherein said power conditioning unit manages a power flow of said distributed power source;

a circuit breaker manager controllably connecting to said power grid, and wherein said circuit breaker manager is connected to said power conditioning unit.

2. A distributed power system for a utility grid according to claim 1, further comprising a heat exchanger for recovering heat from said distributed power source.

3. A distributed power system for a utility grid according to claim 1, wherein said circuit breaker manager controllably connects individual load branches.

4. A distributed power system for a utility grid according to claim 1, wherein said utility grid is a local area grid comprising a plurality of distributed power sources.

5. A segmentable distributed power system, comprising:

two or more power sources connected in parallel;

a power conditioning unit having an output impedance and connecting to each of said power sources on a first side and connecting to a shared load on a second side, wherein said power conditioning system controls said output impedance.

6. A circuit breaker manager for controlling distributed power between a power source and an external power grid, comprising:

a circuit breaker controller;

a plurality of solid state branch circuit breakers controlled by said circuit breaker controller;

a contactor for connecting to said external power grid;

a voltage sensor for measuring said external power grid; and

a means for communicating.

7. A local area grid device for distributed power according to claim 6, wherein said communicating means connects to the Internet.

8. A system for managing a local area grid according to claim 7, further comprising an interface means for connecting said power conditioning unit to a graphical user interface for status, billing, maintenance, and adjustment of system parameters.

9. A method for controlling a local area grid, wherein said grid contains two or more distributed power sources, comprising the steps of:

measuring a grid voltage by each power condition unit;

comparing said grid voltage of each power conditioning unit to a predetermined value;

increasing current output of said power conditioning unit to said local area grid if said grid voltage is less than said predetermined value; and

decreasing current output of said power conditioning unit to said local area grid if said grid voltage is greater than said predetermined value.

10. A distributed power system for a ripple sensitive distributed power source, comprising:

A DC-DC converter serially connecting to said ripple sensitive power source on a first side;

A ripple tolerant power source connecting to said DC-DC converter on a second side;

A phase shifted H-bridge connecting to said second side of said DC-DC converter on a first side;

A DC-AC converter connecting to a second side of said H-bridge; and

A means for forcing ripple sourced from said ripple tolerant power source.