Fuel Cell System with Grid Independent Operation and DC Microgrid Capability

• US 20120146587A1
• Filed: 11/14/2011
• Published: 06/14/2012
• Est. Priority Date: 11/15/2010
• Status: Active Grant

• Current Assignee: Bloom Energy Corporation
• Original Assignee: Bloom Energy Corporation
• Inventors: Srinivasan, Ramesh, Gurunathan, Ranganathan, Ballantine, Arne, McElroy, James, Swaminathan, Rajaram
• Granted Patent: US 9,106,098 B2
• Time in Patent Office: Days
• US Class Current: 320/138
• CPC Class Codes: B60L 53/54 Fuel cells
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H01M 2250/20 Fuel cells in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 8/04619 of fuel cell stacks
• CPC Class Codes: H01M 8/04925 Power, energy, capacity or load
• CPC Class Codes: H01M 8/04947 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H02J 1/108 using diodes blocking reverse current flow H02J1/12 takes precedence
• CPC Class Codes: H02J 1/14 Balancing the load in a network
• CPC Class Codes: H02J 2300/30 The power source being a fuel cell
• CPC Class Codes: H02J 3/322 the battery being on-board an electric or hybrid vehicle, e.g. vehicle to grid arrangements [V2G], power aggregation, use of the battery for network load balancing, coordinated or cooperative battery charging
• CPC Class Codes: H02J 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• CPC Class Codes: H02J 3/381 Dispersed generators
• 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
• CPC Class Codes: H02J 9/00 Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
• CPC Class Codes: H02J 9/061 for DC powered loads
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier
• 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 10/92 : Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y02T 90/167 : Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: Y02T 90/40 : Application of hydrogen technology to transportation, e.g. using fuel cells
• CPC Class Codes: Y04S 10/126 : the energy generation units being or involving electric vehicles [EV] or hybrid vehicles [HEV], i.e. power aggregation of EV or HEV, vehicle to grid arrangements [V2G]
• CPC Class Codes: Y04S 30/12 : Remote or cooperative charging

Abstract

A fuel cell system includes grid independent operation with DC microgrid capability. This fuel cell system has a capability of operation with and without the grid, and with DC micro-grid capability.

Claims

1. A fuel cell system, comprising:

a power module comprising at least one fuel cell segment;

an input output module comprising at least one first inverter; and

an uninterruptible power module comprising at least one second inverter;

wherein;

the at least one fuel cell segment is electrically connected in parallel to the at least one first inverter and the at least one second inverter;

the at least one first inverter is electrically connected to a load through an electrical grid; and

the at least one second inverter is electrically connected to the load without using the electrical grid.

2. The system of claim 1, further comprising a control logic unit.

3. The system of claim 2, wherein the electrical grid and the at least one second inverter are connected to the load through the control logic unit and the control logic unit selects whether to provide power to the load though the electrical grid or through the at least one second inverter.

4. The system of claim 1, wherein the power module comprises a first housing, the input output module comprises a second housing which is separate from the first housing, and the uninterruptible power module comprises a third housing which is separate from the first and the second housings.

5. The system of claim 4, wherein the third housing is located adjacent to the load and the first and the second housings are located further from the load than the third housing.

6. A fuel cell system, comprising:

a power module comprising at least one fuel cell segment;

an input output module comprising at least one first inverter; and

an uninterruptible power module comprising at least one second inverter;

wherein the power module comprises a first housing, the input output module comprises a second housing which is separate from the first housing, and the uninterruptible power module comprises a third housing which is separate from the first and the second housings.

7. The system of claim 6, wherein the third housing is located adjacent to the load and the first and the second housings are located further from the load than the third housing.

8. A method of providing electrical power to a load comprising:

a controller determining a state of a direct current (DC) power unit connected to a DC bus;

the controller selecting a source to power a load based on the state of the power unit, wherein the source is selected from an alternating current (AC) grid and the power unit;

the controller connecting the load to the AC grid when the state of power unit is that it is unavailable to provide power to the load; and

the controller connecting the power unit to the load through a remotely located DC to AC inverter when the state of the power unit is that it is available to provide power to the load.

9. A method of charging electric vehicles comprising:

a controller detecting a connection of an electric vehicle (EV) battery to a DC bus and a state of a direct current (DC) power unit connected to the DC bus;

the controller selecting a source to charge the EV battery based on the state of the power unit, wherein the source is selected from an alternating current (AC) grid and the power unit;

the controller connecting the AC grid to the DC bus through an AC to DC converter to provide power to the EV battery when the state of power unit is that it is unavailable to provide power to the EV battery; and

the controller connecting the power unit to the DC bus when the state of the power unit is that it is available to provide power to the EV battery.

10. A fuel cell system, comprising:

a power module comprising at least one fuel cell segment;

an input output module comprising at least one inverter; and

an electric vehicle charging module (ECM) comprising at least one DC/DC converter;

wherein;

the at least one fuel cell segment is electrically connected in parallel to the at least one inverter and the at least one DC/DC converter;

the at least one inverter is electrically connected to a load or to an electrical grid; and

the at least one DC/DC converter is adapted to be electrically connected to an electrical vehicle battery without using the electrical grid.

11. A fuel cell system, comprising:

a power module comprising at least one fuel cell segment;

a bank of replacement batteries for an electric vehicle; and

an electric vehicle charging module (ECM) comprising at least one DC/DC converter;

wherein the ECM and the bank of replacement batteries are connected in parallel to a DC bus output of the power module.

12. A method of providing electrical power to a load comprising:

receiving DC power from an electric vehicle battery at an electric vehicle charging module (ECM);

providing the received power to the at least one inverter;

converting the received DC power to AC power; and

providing the AC power to a load.

13. The method of claim 12, further comprising:

providing DC power from at least one fuel cell power module to the ECM; and

providing the DC power from the ECM to the electric vehicle battery prior to the step of receiving DC power.

14. The method of claim 12, wherein the electric vehicle battery is charged at a location other than the ECM prior to the step of receiving DC power.