Fuel cell system

Patent metadata

Field	Value
Publication number	US-11465505-B2
Application number	US-201616061433-A
Country	US
Kind code	B2
Filing date	Oct 20, 2016
Priority date	Dec 15, 2015
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

A fuel cell system in which a fuel cell is coupled to a motor driving battery and a vehicular auxiliary machine is coupled to the motor driving battery via a first voltage converter, the fuel cell system including a fuel cell auxiliary machine coupled to the first voltage converter; and a second voltage converter that couples the fuel cell auxiliary machine to the fuel cell.

First claim

The invention claimed is:

1. A fuel cell system comprising:
a fuel cell configured to supply an electric power to an electric power supply line connecting a driving motor and a motor driving battery;
a fuel cell auxiliary machine used for driving the fuel cell;
a first voltage converter branched from the electric power supply line and connecting to a low voltage line connected with the fuel cell auxiliary machine wherein the first voltage converter is configured to step down a first voltage of the electric power supply line and supply the stepped down first voltage to the low voltage line;
a second voltage converter configured to connect the fuel cell and a coupling line branched from the electric power supply line wherein the second voltage converter is configured to step up an output voltage of the fuel cell and supply the stepped up output voltage to the coupling line; and
a third voltage converter configured to connect the coupling line and the low voltage line wherein the third voltage converter is configured to step down a second voltage of the coupling line and supply the stepped down second voltage to the low voltage line.

2. The fuel cell system according to claim 1 , further comprising:
an auxiliary machine battery coupled to the first voltage converter, the auxiliary machine battery having a voltage lower than a voltage of the motor driving battery, wherein
the fuel cell auxiliary machine and the second voltage converter are coupled to the auxiliary machine battery.

3. The fuel cell system according to claim 2 , wherein
the fuel cell system continues an electric generation of the fuel cell until the auxiliary machine battery reaches a predetermined amount of charge in a stop control of the fuel cell system.

4. The fuel cell system according to claim 1 , wherein
the fuel cell auxiliary machine is a fuel supply unit configured to supply a fuel to the fuel cell.

5. The fuel cell system according to claim 1 , further comprising:
a changeover switch configured to switch between a cutoff and an electrical conduction of the coupling line;
a discharge circuit configured; and
a control unit configured to control the changeover switch and the discharge circuit, wherein
the second voltage converter is coupled to a fuel cell side of the coupling line with respect to the changeover switch in the coupling line, and
the control unit is configured to
control the changeover switch to cut off the coupling line when a control to cut off the motor driving battery from the electric power supply line is performed, and
control the discharge circuit to step down a voltage of the electric power supply line.

Assignees

• Nissan Motor

Inventors

• Suzuki Kenta
• Kumada Mitsunori

Classifications

• Y02T90/12

  Electric charging stations · CPC title

• B60L50/71

  Arrangement of fuel cells within vehicles specially adapted for electric vehicles · CPC title

• H01M8/04228

  during shut-down · CPC title

• H01M2250/20

  Fuel cells in motive systems, e.g. vehicle, ship, plane · CPC title

• B60L50/75

  using propulsion power supplied by both fuel cells and batteries · CPC title