Contactor failure detecting apparatus for fuel cell system

• US 7,867,662 B2
• Filed: 05/10/2007
• Issued: 01/11/2011
• Est. Priority Date: 05/10/2006
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Ojima, Kuniaki, Sasaki, Minoru
• Primary Examiner(s): CONLEY, OI K
• Application Number:
  US11/801,720
• Publication Number:
  US 20070264547A1
• Time in Patent Office: 1,342 Days
• Field of Search: 429/432, 429/430, 429/428, 429/400
• US Class Current: 429/432
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: H01M 8/04559 of fuel cell stacks
• CPC Class Codes: H01M 8/04589 of fuel cell stacks
• CPC Class Codes: H01M 8/04686 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A contactor electrically connects and disconnects a fuel cell from a load. When a failure-detecting mode for detecting a closing failure of a contactor is initiated, an opening command is transmitted to the contactor, and a DC/DC converter connected to a motor changes the load voltage. Then, the load voltage and a fuel cell voltage are compared with each other. If the contactor is in a normal open state, as a result of the opening command, the fuel cell voltage is constant, whereas the load voltage of the DC/DC converter decreases, thereby producing a voltage difference. A closing failure of the contactor is determined when it is detected that the fuel cell voltage is substantially equal to the load voltage.

Claims

1. A contactor failure detecting apparatus for use in a fuel cell system comprising:

a fuel cell generates power by reaction of a fuel gas and an oxygen-containing gas, the fuel cell producing a fuel cell voltage (Vfc);

a DC/DC converter increases an output voltage of said fuel cell so as to achieve a predetermined voltage;

a load driven by an output voltage of said DC/DC converter, the load having a load voltage (Vld);

a contactor opens and closes in order to electrically connect and disconnect said fuel cell with respect to said load through said DC/DC converter, said contactor having one end thereof connected to an output side of said fuel cell and another end thereof connected to an input side of said DC/DC converter;

an energy storage device connected to said fuel cell through said DC/DC converter; and

a control device programmed to;

transmit a close command to said contactor;

increase, following the close command, a voltage of the energy storage device so that the load voltage Vld is made higher than the fuel cell voltage Vfc (Vld>

Vfc);

transmit, following the increase of voltage, an ‘

open’

command to said contactor;

monitor the Vld and Vfc for a pre-determined time period; and

identify, based on the monitoring, a contactor failure when said Vld and said Vfc are substantially equal at the end of the pre-determined time period.

2. A contactor failure detecting apparatus for use in a fuel cell system according to claim 1, wherein said control device controls a change in said voltage on said input side of said DC/DC converter such that an electrical power of said fuel cell is smaller than a predetermined electrical power limit value.

3. A contactor failure detecting apparatus for use in a fuel cell system according to claim 1, further comprising:

an air compressor for supplying said oxygen-containing gas to said fuel cell, connected to said load side through an electrical input side of said air compressor,

wherein, while detecting a closing failure of said contactor, said control device drives said air compressor for scavenging said fuel cell.