System and method for controlling power for fuel cell

Patent metadata

Field	Value
Publication number	US-2023170506-A1
Application number	US-202217890247-A
Country	US
Kind code	A1
Filing date	Aug 17, 2022
Priority date	Nov 26, 2021
Publication date	Jun 1, 2023
Grant date	—

Abstract

A system and method for controlling power for a fuel cell are disclosed. The system includes: a fuel cell; a load device electrically connected to the fuel cell; a stack controller configured to set a stack limit current on the basis of a current output current of the fuel cell, the stack limit current configured to limit an output current of the fuel cell on the basis of an output voltage of the fuel cell; and a load controller configured to set a consumption limit current on the basis of the set stack limit current, the consumption limit current configured to limit a consumption current of the load device, the load controller being configured to control the consumption current of the load device to a value equal to or lower than the set consumption limit current.

First claim

What is claimed is:

1 . A system for controlling power for a fuel cell, the system comprising:
a fuel cell; a load device electrically connected to the fuel cell; a stack controller configured to set a stack limit current on the basis of a current output current of the fuel cell, the stack limit current configured to limit an output current of the fuel cell on the basis of an output voltage of the fuel cell; and a load controller configured to set a consumption limit current on the basis of the set stack limit current, the consumption limit current configured to limit a consumption current of the load device, the load controller being configured to control the consumption current of the load device to a value equal to or lower than the set consumption limit current.

2 . The system of claim 1 , wherein the stack controller sets the stack limit current, which is based on the output voltage of the fuel cell, on the basis of the current output current of the fuel cell only when the output voltage of the fuel cell is equal to or lower than a preset reference voltage.

3 . The system of claim 2 , wherein the stack controller divides a voltage range of the fuel cell, which is equal to or lower than the preset reference voltage, into a plurality of sections and sets the stack limit current for each section on the basis of the current output current of the fuel cell at the time of transition between the divided sections.

4 . The system of claim 3 , wherein the stack controller sets a current, which is preset on the basis of the output voltage of the fuel cell, to the stack limit current in a section in which the voltage is lowest among the plurality of divided sections.

5 . The system of claim 1 , further comprising:
a battery electrically connected between the fuel cell and the load device; and a battery controller configured to limit a discharge current of the battery to a value equal to or lower than a discharge limit current.

6 . The system of claim 5 , wherein the load controller sets the consumption limit current by adding the discharge limit current to the set stack limit current.

7 . The system of claim 5 , wherein the battery controller determines whether the battery can assist power on the basis of a state of charge (SOC) of the battery, the discharge limit current, or a maximum discharge time, and the load controller controls the consumption current of the load device to a value equal to or lower than the set consumption limit current only when the battery cannot assist power.

8 . The system of claim 5 , wherein the discharge limit current is determined on the basis of a temperature or a state of charge of the battery.

9 . The system of claim 1 , further comprising:
auxiliary machinery electrically connected between the fuel cell and the load device; and a balance of plant (BOP) controller configured to predict a predicted consumption current predicted to be consumed by the auxiliary machinery, wherein the load controller sets the consumption limit current by subtracting the predicted consumption current from the set stack limit current.

10 . The system of claim 9 , wherein the auxiliary machinery comprises a motor device, and the BOP controller predicts the predicted consumption current on the basis of a difference between a current revolution per minute (RPM) and a command RPM of the motor device.

11 . A method of controlling power for a fuel cell, the method comprising:
setting a stack limit current on the basis of a current output current of the fuel cell, the stack limit current configured to limit an output current of the fuel cell on the basis of an output voltage of the fuel cell; setting a consumption limit current on the basis of the set stack limit current, the consumption limit current configured to limit a consumption current of a load device; and controlling the consumption current of the load device to a value equal to or lower than the set consumption limit current.

12 . The method of claim 11 , further comprising:
comparing the output voltage of the fuel cell with a preset reference voltage before the setting of the stack limit current, wherein in the setting of the stack limit current, the stack limit current, which is based on the output voltage of the fuel cell, is set on the basis of the current output current of the fuel cell only when the output voltage of the fuel cell is equal to or lower than a preset reference voltage.

13 . The method of claim 12 , wherein in the setting of the stack limit current, a voltage range of the fuel cell, which is equal to or lower than the preset reference voltage, is divided into a plurality of sections, and the stack limit current is set for each section on the basis of the current output current of the fuel cell at the time of transition between the divided sections.

14 . The method of claim 13 , wherein in the setting of the stack limit current, a current, which is preset on the basis of the output voltage of the fuel cell, is set to the stack limit current in a section in which a voltage is lowest among the plurality of divided sections.

15 . The method of claim 11 , further comprising:
determining a discharge limit current used to limit a discharge current of a battery electrically connected between the fuel cell and the load device before the setting of the consumption limit current, wherein in the setting of the consumption limit current, the consumption limit current is set by adding the determined discharge limit current to the set stack limit current.

16 . The method of claim 15 , wherein in the determining of the discharge limit current, the discharge limit current is determined on the basis of a temperature or a state of charge of the battery.

17 . The method of claim 15 , further comprising:
determining whether the battery can assist power on the basis of a state of charge (SOC) of the battery, a discharge limit current, or a maximum discharge time before the controlling of the consumption current of the load device, wherein in the controlling of the consumption current of the load device, the consumption current of the load device is controlled to a value equal to or lower than the set consumption limit current only when the battery cannot assist power.

18 . The method of claim 11 , further comprising:
predicting a predicted consumption current predicted to be consumed by auxiliary machinery electrically connected between the fuel cell and the load device, wherein in the setting of the consumption limit current, the consumption limit current is set by subtracting the predicted consumption current from the set stack limit current.

19 . The method of claim 18 , wherein the auxiliary machinery comprises a motor device, and in the predicting of the predicted consumption current, the predicted consumption current is predicted on the basis of a difference between current RPM and command RPM of the motor device.

Assignees

• Hyundai Motor Co Ltd
• Kia Corp

Inventors

• Jeong Seong Cheol
• Park Hyo Jin
• Kim Dae Jong
• Yeom Sang Chul

Classifications

• H02J7/977 Primary

  of the battery · CPC title

• H02J7/933

  the cycle being controlled or terminated in response to electric parameters · CPC title

• H02J7/82

  Control of state of charge [SOC] · CPC title

• Y02E60/50

  Fuel cells · CPC title

• H02J2101/30

  Fuel cells · CPC title