System for improving startability of fuel cell vehicle and control method thereof

Patent metadata

Field	Value
Publication number	US-2023406157-A1
Application number	US-202217980882-A
Country	US
Kind code	A1
Filing date	Nov 4, 2022
Priority date	Jun 15, 2022
Publication date	Dec 21, 2023
Grant date	—

Abstract

A startability improving system of a fuel cell vehicle is disclosed. The startability improving system includes a high-voltage battery and a fuel cell connected to a main bus stage of the vehicle, to provide driving energy, and a controller configured to determine whether there is a possibility that operating voltages of the high-voltage battery and the fuel cell overlap each other when the high-voltage battery and the fuel cell are connected to the main bus stage, in response to determination that there is a possibility that the operating voltages of the high-voltage battery and the fuel cell overlap each other, the controller configured to vary the operating voltage of the high-voltage battery or the fuel cell, and then to connect the high-voltage battery and the fuel cell to the main bus stage.

First claim

What is claimed is:

1 . A startability improving system of a fuel cell vehicle comprising:
a high-voltage battery and a fuel cell connected to a main bus stage of the fuel cell vehicle, to provide driving energy; and a controller configured to determine whether there is a possibility that operating voltages of the high-voltage battery and the fuel cell overlap each other when the high-voltage battery and the fuel cell are connected to the main bus stage, in response to determination that there is a possibility that the operating voltages of the high-voltage battery and the fuel cell overlap each other, the controller configured to vary the operating voltage of the high-voltage battery or the fuel cell, and then to connect the high-voltage battery and the fuel cell to the main bus stage.

2 . The startability improving system according to claim 1 , wherein:
the controller compares an output voltage of the high-voltage battery upon start of the vehicle with an expected voltage of the fuel cell derived based on a previously-prepared first data map, thereby determining whether there is a possibility that the operating voltages of the high-voltage battery and the fuel cell overlap each other, the first data map includes a temperature of the fuel cell as an input thereof and the expected voltage as an output thereof.

3 . The startability improving system according to claim 1 , wherein:
the controller compares a charge amount of the high-voltage battery upon start of the vehicle with a required charge amount of the high-voltage battery derived based on a prepared second data map, thereby determining whether there is a possibility that the operating voltages of the high-voltage battery and the fuel cell overlap each other, the second data map includes a temperature of the high-voltage battery as an input thereof and the required charge amount as an output thereof.

4 . The startability improving system according to claim 1 , wherein in response to determination that there is a possibility that the operating voltages of the high-voltage battery and the fuel cell overlap each other, the controller controls a temperature of the high-voltage battery or the fuel cell to vary the operating voltage of the high-voltage battery or the fuel cell.

5 . The startability improving system according to claim 4 , wherein the controller determines whether temperature control for the high-voltage battery is possible, based on a charge amount of the high-voltage battery, and in response to determination that the temperature control for the high-voltage battery is possible, the controller performs temperature increase control for the high-voltage battery to raise the operating voltage of the high-voltage battery.

6 . The startability improving system according to claim 5 , further comprising:
a heater for the high-voltage battery configured to increase a temperature of the high-voltage battery using cooling water, wherein the controller drives the heater for the high-voltage battery through the high-voltage battery, to perform the temperature increase control for the high-voltage battery.

7 . The startability improving system according to claim 5 , wherein the controller determines whether the temperature control for the high-voltage battery is possible based on an available electric power amount according to the charge amount of the high-voltage battery and a heat capacity required for temperature increase of the high-voltage battery.

8 . The startability improving system according to claim 7 , wherein the controller derives the heat capacity required for temperature increase of the high-voltage battery, based on the following Expression:
Heat Capacity Required for Temperature Increase of High-Voltage Battery=(Target Heat Capacity of High-Voltage Battery−Current Heat Capacity of High-Voltage Battery)/Temperature Increase Efficiency of High-Voltage Battery.  [Expression]

9 . The startability improving system according to claim 7 , wherein the controller periodically derives the heat capacity required for temperature increase of the high-voltage battery during the temperature increase control for the high-voltage battery, and compares the periodically-derived heat capacity required for temperature increase of the high-voltage battery with the available electric power amount according to the charge amount of the high-voltage battery, thereby determining whether the temperature control for the high-voltage battery is possible.

10 . The startability improving system according to claim 4 , wherein the controller determines whether temperature control for the high-voltage battery is possible, based on a charge amount of the high-voltage battery, and in response to determination that the temperature control for the high-voltage battery is possible, the controller performs temperature increase control for the fuel cell upon to lower the operating voltage of the fuel cell.

11 . The startability improving system according to claim 10 , further comprising:
a fuel cell main relay, provided between the main bus stage of the vehicle and the fuel cell, configured to connect or disconnect the fuel cell and the main bus stage; and a cathode oxygen depletion (COD) heater, provided between the fuel cell main relay and the fuel cell, configured to remove residual oxygen and hydrogen in an interior of the fuel cell, wherein the controller drives the COD heater through the fuel cell in a state of disconnecting the fuel cell and the main bus stage by controlling the fuel cell main relay, thereby performing the temperature increase control for the fuel cell.

12 . The startability improving system according to claim 11 , wherein the controller controls the fuel cell main relay to connect the fuel cell to the main bus stage when the operating voltage of the fuel cell is lowered below a predetermined reference value through the temperature increase control for the fuel cell.

13 . A control method of a startability improving system of a fuel cell vehicle comprising a high-voltage battery, a fuel cell and a controller, the method comprising:
determining, by the controller, whether there is a possibility that operating voltages of the high-voltage battery and the fuel cell overlap when the high-voltage battery and the fuel cell are connected to a main bus stage of the fuel cell vehicle; in response to determination that there is a possibility that the operating voltages of the high-voltage battery and the fuel cell overlap, varying, by the controller, the operating voltage of the high-voltage battery or the fuel cell; and connecting, by the controller, the high-voltage battery and the fuel cell to the main bus stage.

14 . The method according to claim 13 , wherein:
the determining comprising: comparing, by the controller, an output voltage of the fuel cell upon start of the vehicle with an expected voltage of the fuel cell derived based on a previously-prepared first data map; and comparing, by the controller, a charge amount of the high-voltage battery upon start of the vehicle with a required charge amount of the high-voltage battery derived based on a previously-prepared second data map to determine the possibility, wherein the first data map includes a temperature of the fuel cell as an input thereof and the expected voltage of the fuel cell as an output thereof, and the second data map includes a temperature of the high-voltage battery as an input thereof and the required charge amount of the high-voltage battery as an output thereof.

15 . The method according to claim 13 , wherein the varying comprising:
controlling, by th

Assignees

• Hyundai Motor Co Ltd
• Kia Corp

Inventors

• Jung Jae Kwon
• Jeong Seong Cheol

Classifications

• B60L58/31 Primary

  for starting of fuel cells · CPC title

• B60L58/40 Primary

  for controlling a combination of batteries and fuel cells · CPC title

• B60L58/27

  by heating · CPC title

• H01M8/04302

  applied during start-up · CPC title

• H01M8/0488 Primary

  of fuel cell stacks · CPC title