Fuel cell system with connector welding prevention

• US 9,502,725 B2
• Filed: 06/09/2009
• Issued: 11/22/2016
• Est. Priority Date: 06/09/2009
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Okamoto, Shohei, Matsushima, Katsuhiro, Kanie, Naoki
• Primary Examiner(s): Cavallari, Daniel
• Application Number:
  US13/376,979
• Publication Number:
  US 20120086278A1
• Time in Patent Office: 2,723 Days
• Field of Search: 307/130, 307/10.1
• US Class Current: 1/1
• CPC Class Codes: H01M 2250/20 Fuel cells in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 8/04559 of fuel cell stacks
• CPC Class Codes: H01M 8/0488 of fuel cell stacks
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

Weld of a relay provided on an electric power supply path can be suppressed. When a fuel cell system starts, a controller sets an output voltage of a Bat converter at an open circuit voltage of a battery and sets an output voltage of a FC converter at an open circuit voltage of a fuel cell. When the output voltage of the FC converter is lower than the output voltage of the Bat converter, the controller controls to boost the output voltage of the FC converter to the output voltage of the Bat converter. On the other hand, when the output voltage of the FC converter is the output voltage of the Bat converter or more, the controller controls to boost the output voltage of the Bat converter to the output voltage of the FC converter. When the output voltage difference between the FC converter and the Bat converter is a predetermined value or less capable of turning the FC relays ON without causing welding of the FC relays, the controller turns the FC relays ON.

Claims

1. A fuel cell system, comprising:

a fuel cell that receives fuel gas and oxidation gas and generates electric power through electrochemical reaction of the fuel gas and the oxidation gas;

a storage section capable of charging with the electric power generated at the fuel cell;

an electric power consumption device that consumes electric power from the fuel cell and the storage section;

a first voltage converter disposed between the fuel cell and the electric power consumption device;

a second voltage converter disposed between the storage section and the electric power consumption device;

a connector that connects or disconnects a path, the path supplying electric power from the first voltage converter to the electric power consumption device and coupling the first voltage converter and the second voltage converter; and

a controller that is programmed to control connection or disconnection of the path supplying electric power by the connector,

wherein when the system starts, the controller is further programmed to compare an output voltage difference between the first voltage converter and the second voltage converter with a predetermined value that is set as a value at which welding of the connector occurs, and

wherein the controller is further programmed to maintain the output voltage difference equal to or less than the predetermined value, and to subsequently connect the path,

wherein the controller is further programmed to control the output voltage difference to be a predetermined value or less by boosting an output voltage of the first voltage converter.

2. The fuel cell system according to claim 1, wherein the output voltage difference is controlled to be a predetermined value or less by, when an open circuit voltage of the fuel cell is lower than an open circuit voltage of the storage section, boosting an output voltage of the first voltage converter to the open circuit voltage of the storage section.

3. The fuel cell system according to claim 1, wherein the controller is programmed to control the output voltage difference to be a predetermined value or less by, when an output voltage of the first voltage converter is lower than a minimum voltage that can be boosted by the second converter, boosting the output voltage of the first converter to the minimum voltage and boosting an output voltage of the second voltage converter to the minimum voltage.

4. The fuel cell system according to claim 1, wherein the controller is programmed to control to consume electric power of the storage section so as to make the output voltage difference a predetermined value or less.