Fuel cell system

• US 8,432,168 B2
• Filed: 10/23/2008
• Issued: 04/30/2013
• Est. Priority Date: 11/08/2007
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kawase, Ayako
• Primary Examiner(s): Fantu, Yalkew
• Application Number:
  US12/741,794
• Publication Number:
  US 20100264930A1
• Time in Patent Office: 1,650 Days
• Field of Search: 324/430
• US Class Current: 324/430
• CPC Class Codes: H01M 16/006 of fuel cells with rechargeable batteries
• CPC Class Codes: H01M 2008/1095 Fuel cells with polymeric electrolytes
• CPC Class Codes: H01M 8/04246 Short circuiting means for defective fuel cells detection of defective fuel cells H01M8/04664, methods for shunting fuel cells H01M8/04955
• CPC Class Codes: H01M 8/04365 of other components of a fuel cell or fuel cell stacks
• CPC Class Codes: H01M 8/04552 of the individual fuel cell
• CPC Class Codes: H01M 8/04559 of fuel cell stacks
• CPC Class Codes: H01M 8/04589 of fuel cell stacks
• CPC Class Codes: H01M 8/04611 of the individual fuel cell
• CPC Class Codes: H01M 8/04619 of fuel cell stacks
• CPC Class Codes: H01M 8/04626 of auxiliary devices, e.g. batteries, capacitors
• CPC Class Codes: H01M 8/04641 of the individual fuel cell
• CPC Class Codes: H01M 8/04649 of fuel cell stacks
• CPC Class Codes: H01M 8/04671 of the individual fuel cell
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

There is provided an impedance measuring system which can accurately measure the impedance of a fuel cell. A motor rotation number detection unit successively detects the rotation number of a motor controlled by an inverter and outputs the detection result to a superposition signal generation unit. The superposition signal generation unit sets the frequency of an impedance measuring signal to a non-resonant frequency so that the control signal of the motor will not resonate with the impedance measuring signal. Thus, by setting the frequency of the impedance measuring signal to the non-resonant frequency, the resonance with the motor is suppressed, which can improve impedance measurement accuracy.

Claims

1. An impedance measuring system which measures the impedance of a fuel cell, including:

an electronic device connected to the fuel cell and controlled by a frequency;

a detection device that detects the frequency of a control signal to control the electronic device;

a decision device that determines the measurement frequency of the impedance based on the detected frequency; and

a measurement device that measures the impedance at the determined measurement frequency,

wherein the decision means determines, as the measurement frequency of the impedance, a frequency which does not resonate with the detected frequency.

2. The impedance measuring system according to claim 1, wherein the electronic device is a motor connected to the fuel cell.

3. An impedance measuring system which measures the impedance of a fuel cell, including:

an electronic device connected to the fuel cell and controlled by a frequency;

a control device configured to detect the frequency of a control signal to control the electronic device;

configured to determine the measurement frequency of the impedance based on the detected frequency; and

configured to measure the impedance at the determined measurement frequency,

wherein the control device determines, as the measurement frequency of the impedance, a frequency which does not resonate with the detected frequency.

4. The impedance measuring system according to claim 3, wherein the electronic device is a motor connected to the fuel cell.