{
  "$type": "site.standard.document",
  "description": "The invention provides an apparatus for estimating fuel-cell hydrogen concentration and a fuel cell system which exploit the correlation between impedance semicircles and hydrogen concentrations to estimate fuel-cell hydrogen concentration. A fuel cell system includes a fuel cell 2, an impedance…",
  "path": "/patents/1004439",
  "publishedAt": "2012-03-14T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "G01N27/02",
    "TOYOTA MOTOR CO LTD [JP]"
  ],
  "textContent": "The invention provides an apparatus for estimating fuel-cell hydrogen concentration and a fuel cell system which exploit the correlation between impedance semicircles and hydrogen concentrations to estimate fuel-cell hydrogen concentration. A fuel cell system includes a fuel cell 2, an impedance measuring instrument 3, and a control device 5. The control device 5 is connected to the impedance measuring instrument 3. The impedance measuring instrument 3 measures the impedance of the fuel cell 2 according to the AC impedance method. The control device 5 stores in advance a reference value corresponding to a reference hydrogen concentration. The control device 5 compares the real part Z' of impedance acquired via the impedance measuring instrument 3 against the reference value. When Z' is equal to or greater than the reference value, the control device 5 estimates the hydrogen concentration of the fuel cell 2 to be equal to or less than the reference hydrogen concentration.",
  "title": "FUEL CELL HYDROGEN CONCENTRATION ESTIMATION DEVICE AND FUEL CELL SYSTEM"
}