Fuel cell system

• US 8,343,673 B2
• Filed: 09/26/2007
• Issued: 01/01/2013
• Est. Priority Date: 10/24/2006
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Yamashita, Kiyomi
• Primary Examiner(s): Ryan, Patrick
• Assistant Examiner(s): Mohaddes, Ladan
• Application Number:
  US11/861,864
• Publication Number:
  US 20080096068A1
• Time in Patent Office: 1,924 Days
• Field of Search: 429/13, 429/428, 429/431, 429/432, 429/433, 429/442, 429/90
• US Class Current: 429/428
• CPC Class Codes: H01M 8/04037 Electrical heating
• CPC Class Codes: H01M 8/04619 of fuel cell stacks
• CPC Class Codes: H01M 8/04679 of fuel cell stacks
• CPC Class Codes: H01M 8/04753 of fuel cell reactants
• CPC Class Codes: H01M 8/04947 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A fuel cell system is provided with a fuel cell, a system power source, an inverter system and a fuel gas supply device for supplying the fuel cell with fuel gas of a regulated quantity, wherein when the system power source falls in a power failure during the power use by the external loads, at least one of the power use by the internal loads (resistances) and the supply quantity of the fuel gas supply device is altered in dependence on the output power from the fuel cell or the power use by the external loads.

Claims

1. A fuel cell system comprising:

a fuel cell to generate electric power through the reaction of fuel gas with oxidizing gas to supply the generated electric power to internal loads and external loads which are arranged respectively inside and outside the fuel cell system, the internal loads including at least one resistance;

a system power source to supply electric power to the internal loads and the external loads;

an inverter system coupled between the fuel cell and the system power source, and having a first function of converting direct current voltage outputted from the fuel cell into predetermined alternating current voltage to output the alternating current voltage to power lines connected to the system power source, a second function of converting alternating current voltage from the power lines into predetermined direct current voltage to output the direct current voltage to the internal loads, and a third function of converting the direct current voltage from the fuel cell into predetermined direct current voltage to output the direct current voltage to the internal loads;

a fuel gas supply device to supply the fuel cell with fuel gas of a regulated quantity;

a power failure breaker relay between the inverter system and the system power source;

a temperature sensor that detects a temperature of the resistance;

a switch that connects the resistance to an electrical output of the fuel cell; and

a controller programmed to increase power use by the internal loads in dependence on a power output state of the fuel cell detected from an output power from the fuel cell or the power use by the external loads when the system power source falls in a power failure during power use by the external loads,

wherein the controller increases the power use by opening the power failure breaker relay and by operating the switch so an amount of power used by the external loads prior to the power failure breaker relay being opened is used by the resistance, the switch being operated for a predetermined time if the temperature of the resistance does not exceed a predetermined temperature.

2. The fuel cell system as set forth in claim 1, wherein the at least one resistance is arranged between the fuel cell and the inverter system in parallel to the inverter system.

3. The fuel cell system as set forth in claim 2,

wherein the at least one resistance includes a plurality of resistances connected in parallel to one another, and

wherein the fuel cell system further includes switches provided in series respectively to the respective resistances that switch active states and passive states of the respective resistances.

4. The fuel cell system as set forth in claim 1, wherein the internal loads comprise an existing heater device provided for heating the fuel cell system.

5. The fuel cell system as set forth in claim 1, wherein

the inverter system includes an output terminal to output the alternating current voltage to the power lines connected to the system power source, and

the output terminal is disconnected from the power lines when the system power source falls in the power failure.

6. The fuel cell system as set forth in claim 1, wherein the controller intermittently opens and closes the switch in dependence on the output power state of the fuel cell detected from the output power from the fuel cell or the power use by the external loads.

7. The fuel cell system as set forth in claim 6,

wherein a ratio of a switch open time to a switch closed time is determined in dependence on the output power state of the fuel cell detected from the output power from the fuel cell or the power use by the external loads.

10. The fuel cell system as set forth in claim 1, wherein the resistance is 300 watts.

8. A fuel cell system comprising:

a fuel cell to generate electric power through the reaction of fuel gas with oxidizing gas to supply the generated electric power to internal loads and external loads which are arranged respectively inside and outside the fuel cell system, the internal loads including at least one resistance;

a system power source to supply electric power to the internal loads and the external loads;

an inverter system coupled between the fuel cell and the system power source, and having a first function of converting direct current voltage outputted from the fuel cell into predetermined alternating current voltage to output the alternating current voltage to power lines connected to the system power source, a second function of converting alternating current voltage from the power lines into predetermined direct current voltage to output the direct current voltage to the internal loads, and a third function of converting the direct current voltage from the fuel cell into predetermined direct current voltage to output the direct current voltage to the internal loads;

a fuel gas supply device to supply the fuel cell with fuel gas of a regulated quantity;

a power failure breaker relay between the inverter system and the system power source;

a temperature sensor that detects a temperature of the resistance; and

a switch that connects the resistance to an electrical output of the fuel cell; and

means for increasing power use by the internal loads in dependence on a power output state of the fuel cell detected from an output power from the fuel cell or the power use by the external loads when the system power source falls in a power failure during power use by the external loads, including opening the power failure breaker relay and operating the switch so an amount of power used by the external loads prior to the power failure breaker relay being opened is used by the resistance,

wherein the means for increasing power operates the switch to increase the power use by the internal loads for a predetermined time if the temperature of the resistance does not exceed a predetermined temperature.

9. The fuel cell system as set forth in claim 8, wherein the means for increasing the power use by the internal loads opens and closes the switch in dependence on the output power state of the fuel cell detected from the output power from the fuel cell or the power use by the external loads.

11. The fuel cell system as set forth in claim 8, wherein the resistance is 300 watts.