FUEL CELL SYSTEM

• US 20130057292A1
• Filed: 03/22/2011
• Published: 03/07/2013
• Est. Priority Date: 04/02/2010
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Hasegawa, Takahiko, Kitamura, Nobuyuki
• Granted Patent: US 8,952,702 B2
• Time in Patent Office: Days
• US Class Current: 324/430
• CPC Class Codes: G01R 31/389 Measuring internal impedance, internal conductance or related variables
• CPC Class Codes: H01M 2008/1095 Fuel cells with polymeric electrolytes
• 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 8/04589 of fuel cell stacks
• CPC Class Codes: H01M 8/04649 of fuel cell stacks
• CPC Class Codes: H01M 8/04828 Humidity; Water content
• 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

A fuel cell system includes a fuel cell, a multiphase voltage conversion device with N-phases (N being an integer equal to or larger than two) that is connected to the fuel cell, a control signal generation portion that generates control signals to control each phase of the multiphase voltage conversion device by superimposing a control waveform for measuring impedance on a voltage indicating an output target voltage of the multiphase voltage conversion device and sequentially outputs the control signals corresponding to N phases with a predetermined phase difference to the multiphase voltage conversion device, and an impedance calculation portion that measures a current and a voltage of the fuel cell on cycles corresponding to N predetermined sampling frequencies having a phase difference equal to the predetermined phase difference and calculates an impedance of the fuel cell based on the measured current and the measured voltage.

Claims

1. A fuel cell system comprising:

a fuel cell;

a multiphase voltage conversion device with N-phases (N being an integer equal to or larger than two) that is connected to the fuel cell;

a control signal generation portion that generates control signals to control each phase of the multiphase voltage conversion device by superimposing a control waveform for measuring impedance on a voltage indicating an output target voltage of the multiphase voltage conversion device, and sequentially outputs the control signals corresponding to N phases with a predetermined phase difference to the multiphase voltage conversion device; and

an impedance calculation portion that measures a current of the fuel cell and a voltage of the fuel cell on cycles corresponding to N predetermined sampling frequencies having a phase difference equal to the predetermined phase difference, and calculates an impedance of the fuel cell based on the measured current and the measured voltage.

2. The fuel cell system according to claim 1, wherein the predetermined phase difference is 360°

/N.

3. The fuel cell system according to claim 1, further comprising an accumulator, and a voltage conversion device that is connected to the accumulator.

5. The fuel cell system according to claim 1, wherein the predetermined phase difference is stored in advance in a storage area inside a control unit of the fuel cell system.

4. A method of measuring an impedance of a fuel cell system that includes a fuel cell and a multiphase voltage conversion device with N-phases (N being an integer equal to or larger than two) that is connected to the fuel cell, the method comprising:

generating control signals to control each phase of the multiphase voltage conversion device by superimposing a control waveform for measuring impedance on a voltage indicating an output target voltage of the multiphase voltage conversion device;

sequentially outputting signals corresponding to N phases with a predetermined phase difference to the multiphase voltage conversion device; and

measuring a current of the fuel cell and a voltage of the fuel cell on cycles corresponding to N predetermined sampling frequencies having a phase difference equal to the predetermined phase difference, and calculating an impedance of the fuel cell based on the measured current and the measured voltage.