Control method for fuel cell system, and fuel cell system

Patent metadata

Field	Value
Publication number	US-2022340047-A1
Application number	US-201917765980-A
Country	US
Kind code	A1
Filing date	Oct 4, 2019
Priority date	Oct 4, 2019
Publication date	Oct 27, 2022
Grant date	—

Abstract

A control method includes acquiring the operation stop request of the fuel cell system, acquiring a next vehicle operation start timing, and calculating a first energy cost and a second energy cost at a predetermined timing after acquiring the operation stop request and the next vehicle operation start timing. The first energy cost is an energy cost required from the predetermined timing to completion of warming up of the fuel cell when a warm-up control is executed using the heater in accordance with the next vehicle operation start timing after the stop control is executed. The second energy cost is an energy cost required when an operation of the fuel cell is continued so as to maintain a temperature of the fuel cell at a warm-up temperature from the predetermined timing to the next vehicle operation start timing. The control method includes continuing the operation of the fuel cell such that the temperature of the fuel cell is maintained at the warm-up temperature while the first energy cost is larger than the second energy cost after the operation stop request is acquired.

First claim

1 . A control method for a fuel cell system for a vehicle, the fuel cell system including a fuel cell, and a heater configured to warm up the fuel cell, and capable of executing a stop control when an operation stop request of the fuel cell system is received, the control method comprising:
acquiring the operation stop request of the fuel cell system; acquiring a next vehicle operation start timing; calculating a first energy cost and a second energy cost at a predetermined timing after acquiring the operation stop request and the next vehicle operation start timing,
the first energy cost being an energy cost required from the predetermined timing to completion of warming up of the fuel cell when a warm-up control is executed using the heater in accordance with the next vehicle operation start timing after the stop control is executed, and
the second energy cost being an energy cost required when an operation of the fuel cell is continued so as to maintain a temperature of the fuel cell at a warm-up temperature from the predetermined timing to the next vehicle operation start timing; and
continuing the operation of the fuel cell such that the temperature of the fuel cell is maintained at the warm-up temperature while the first energy cost is larger than the second energy cost after the operation stop request is acquired.

2 . The control method for a fuel cell system according to claim 1 , further comprising:
starting the stop control when the first energy cost is equal to or less than the second energy cost after the operation stop request is acquired.

3 . The control method for a fuel cell system according to claim 1 , wherein
a pre-start stack temperature is calculated based on a stop time from the predetermined timing to starting of the warm-up control and a stack temperature at the predetermined timing, and the first energy cost is calculated based on the calculated pre-start stack temperature.

4 . The control method for a fuel cell system according to claim 1 , wherein
a stack electricity quantity in an electricity generation duration is calculated based on a duration from the predetermined timing to the next vehicle operation start timing and an electricity generation output of the fuel cell, and the second energy cost is calculated based on the stack electricity quantity and electricity conversion efficiency of the fuel cell system.

5 . The control method for a fuel cell system according to claim 1 , wherein
the fuel cell system further includes a battery as a vehicle power supply, and a charging connector configured to be connected to a charging unit of an external charger, the battery is configured to be charged by at least one of the fuel cell and the external charger, and the control method for a fuel cell system further comprises: calculating a third energy cost required when the battery is charged to a target charge quantity by the external charger when the fuel cell system is connected to the external charger; and continuing the operation of the fuel cell such that the temperature of the fuel cell is maintained at the warm-up temperature while a sum of the first energy cost and the third energy cost is larger than the second energy cost, and starting the stop control when the sum of the first energy cost and the third energy cost is equal to or less than the second energy cost after the operation stop request is acquired.

6 . The control method for a fuel cell system according to claim 5 , wherein
a stack electricity quantity in an electricity generation duration is calculated based on a duration from the predetermined timing to the next vehicle operation start timing and an electricity generation output of the fuel cell, and the third energy cost is calculated based on the target charge electricity quantity of the battery and the stack electricity quantity.

7 . The control method for a fuel cell system according to claim 1 , wherein
the fuel cell system further includes a battery as a vehicle power supply, and a charging connector configured to be connected to a charging unit of an external charger, the battery is configured to be charged by at least one of the fuel cell and the external charger, and the control method for a fuel cell system further comprises: setting a plurality of different electricity generation durations at a stop request acquisition timing when the fuel cell system is connected to the external charger; calculating a sum of a fourth energy cost, a fifth energy cost, and a sixth energy cost as a total energy cost for each of the electricity generation durations,
the fourth energy cost being an energy cost required from the stop request acquisition timing to completion of warming up of the fuel cell when the stop control is executed after the set electricity generation duration is elapsed and a warm-up control is executed using the heater in accordance with the next vehicle operation start timing,
the fifth energy cost being an energy cost required when a fuel cell generates electricity only in the set electricity generation duration from the stop request acquisition timing, and
the sixth energy cost being an energy cost required when the battery is charged to a target charge quantity by the external charger; and
continuing the operation of the fuel cell such that the temperature of the fuel cell is maintained at the warm-up temperature from the stop request acquisition timing to when the electricity generation duration at which the total energy cost is lowest is elapsed, and starting the stop control after the electricity generation duration is elapsed.

8 . A fuel cell system for a vehicle, the fuel cell system being capable of executing a stop control when an operation stop request of the fuel cell system is received, the fuel cell system comprising:
a fuel cell; a heater configured to warm up the fuel cell; and a controller configured to determine whether the stop control is to be executed, wherein the controller is configured to:
acquire the operation stop request of the fuel cell system;
acquire a next vehicle operation start timing;
calculate a first energy cost and a second energy cost at a predetermined timing after acquiring the operation stop request and the next vehicle operation start timing,
the first energy cost being an energy cost required from the predetermined timing to completion of warming up of the fuel cell when a warm-up control is executed using the heater in accordance with the next vehicle operation start timing after the stop control is executed, and
the second energy cost being an energy cost required when an operation of the fuel cell is continued so as to maintain a temperature of the fuel cell at a warm-up temperature from the predetermined timing to the next vehicle operation start timing; and

continue the operation of the fuel cell such that the temperature of the fuel cell is maintained at the warm-up temperature while the first energy cost is larger than the second energy cost after the operation stop request is acquired.

Assignees

• Nissan Motor
• Renault Sas

Inventors

• Fukushima Eisuke
• Takeda Hiroshi
• Chikugo Hayato

Classifications

• H01M2250/20

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

• H01M8/0432

  Temperature; Ambient temperature · CPC title

• H01M8/04701

  Temperature · CPC title

• H01M8/04303

  applied during shut-down · CPC title

• B60L58/34 Primary

  by heating · CPC title