Modular DC cogenerator systems

• US 5,969,435 A
• Filed: 03/19/1997
• Issued: 10/19/1999
• Est. Priority Date: 01/08/1991
• Status: Expired due to Fees

• Current Assignee: Nextek Power Systems, Inc.
• Original Assignee: Nextek Power Systems, Inc.
• Inventors: Wilhelm, William George
• Primary Examiner(s): PALADINI, ALBERT WILLIAM
• Application Number:
  US08/820,553
• Time in Patent Office: 944 Days
• Field of Search: 307/43, 307/64, 307/66, 307/65, 307/80, 307/85, 307/86, 307/87
• US Class Current: 307/64
• CPC Class Codes: H02J 1/06 Two-wire systems
• CPC Class Codes: H02J 1/10 Parallel operation of dc sources
• CPC Class Codes: H02J 9/061 for DC powered loads
• CPC Class Codes: Y02B 10/70 Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies
• CPC Class Codes: Y02B 90/10 Applications of fuel cells in buildings
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 20/14 Combined heat and power generation [CHP]

Abstract

A DC power system receives AC electrical power and DC electrical power from separate first and second sources simultaneously. The DC power system delivers DC electrical power to an output for use by a load requiring DC power. The DC power system includes a converter to convert AC electrical power to DC electrical power and a power sharing control device to control and distribute the DC electrical power to an output. The first source of DC electrical power includes a storage battery, which provides standby DC electrical power to the DC power system. It also includes a power sharing device, which maintains the storage battery fully charged for use at peak loads, when the DC output electrical power is insufficient to meet the DC load. The second source of DC electrical power is a cogenerator such as a fuel cell, a thermo photovoltaic generator or an internal combustion engine and an alternator for generating and delivering DC electrical power to the power sharing device, while producing and delivering waste heat for use of an external load requiring this heat.

Claims

1. A power sharing modular DC cogeneration system comprising:

DC power system means capable of receiving AC electrical power and DC electrical power from first and second sources simultaneously and delivering DC electrical power to an output for use by a load requiring DC power;

said DC power system means comprising both means for converting said AC electrical power to DC electrical power and power sharing means for controlling and distributing said DC electrical power to said output;

the first source of DC electrical power comprising storage battery means for providing standby DC electrical power to said DC power system means, said power sharing means maintaining said storage battery fully charged for use at peak loads when the DC output electrical power is insufficient to meet the DC load; and

the second source of DC electrical power being cogeneration means for generating and delivering DC electrical power to said power sharing means while producing and delivering waste heat for use of an external load requiring said heat.

2. The power sharing modular DC cogeneration system of claim 1 in which said cogeneration means comprises a combustion engine and an alternator.

3. The power sharing modular DC cogeneration system of claim 1 in which said cogeneration means comprises a fuel cell.

4. The power sharing modular DC cogeneration system of claim 1 in which said cogeneration means comprises a thermo photovoltaic generator.

5. An emergency power system comprising:

DC electrical control means for receiving, singly and together, a source of AC electrical power and least one low voltage DC power source;

said DC electrical control means capable of receiving DC electrical power from first and second sources simultaneously and delivering DC electrical power to an output for use by a load requiring DC power;

said DC power system means converting said AC electrical power to DC electrical power and controlling and distributing said DC electrical power to said output;

said first source of DC electrical power comprising storage battery means for providing standby DC electrical power to said DC power system means, said DC power system maintaining said storage battery fully charged for use at peak loads when the DC output electrical power is insufficient to meet the DC load; and

said second source of DC electrical power being cogeneration means for generating and delivering DC electrical power to said DC power system when there is an AC power outage, said cogeneration means producing and delivering waste heat for use of an external load requiring said heat.

6. The emergency power system of claim 5 in which said cogeneration means remains inoperative on a standby basis and includes means for automatically being started when any AC power outage lasts past a predetermined time or if the charge in said battery means should drop below a predetermined level.

7. The emergency power system of claim 6 in which said cogeneration means comprises an internal combustion engine.

8. A power sharing modular low voltage DC cogeneration system comprising:

a DC subsystem device responsive to receiving, singly and together, a source of AC power and at least one low voltage DC power source;

said DC subsystem device comprising multiple functions for converting said AC electrical power into low voltage DC electrical power and combining and sharing said power with one or more external low voltage DC power sources in service to a compatible low voltage DC load.

9. An emergency power system comprising:

DC power system means capable of receiving AC electrical power and converting said AC electrical power to supply power to charge, and keep charged, a low voltage storage battery;

said DC power system means also capable of receiving DC power from a DC generator means;

said DC power system means supplying DC power to an inverter which supplies connected AC loads during an AC power outage; and

,

said DC generator means being sized to supply only average AC loads with a small margin to keep said storage battery charged, wherein peak AC loads are supplied by said storage battery.

10. The power sharing modular DC cogeneration system of claim 9 in which said cogeneration means comprises a combustion engine and an alternator.

11. The power sharing modular DC cogeneration system of claim 9 in which said cogeneration means comprises a fuel cell.

12. The power sharing modular DC cogeneration system of claim 9 in which said cogeneration means comprises a thermo photovoltaic generator.

13. The emergency power system of claim 9 in which said generation means remains inoperative on a standby basis and includes means for automatically being started when any AC power outage lasts past a predetermined time or if the charge in said battery means should drop below a predetermined level.

14. The emergency power system of claim 9 in which said generation means comprises an internal combustion engine.