CN-122029649-A - Fuel cell system

CN122029649ACN 122029649 ACN122029649 ACN 122029649ACN-122029649-A

Abstract

A fuel cell system includes a fuel cell and a battery connected to the fuel cell and charged with electric power generated by the fuel cell, wherein the fuel cell system is a system in which a current of the fuel cell depends on a voltage of the battery, and when a state of charge (SOC) of the battery becomes equal to or lower than a SOC lower limit value, control is performed to start electric power generation of the fuel cell, and the SOC lower limit value is changed according to the current of the fuel cell or according to a degradation state of the battery.

Inventors

Shallowly marshes

Assignees

爱三工业株式会社

Dates

Publication Date: 20260512
Application Date: 20240827
Priority Date: 20231101

Claims (3)

1. A fuel cell system having a fuel cell, and a storage battery connected to the fuel cell and charged with electric power generated by the fuel cell, the fuel cell system being characterized in that, The fuel cell system is a system in which the current of the fuel cell depends on the voltage of the battery, When the state of charge (SOC) of the battery is equal to or lower than a lower limit value of the SOC, control is performed to start power generation of the fuel cell, The SOC lower limit value is changed according to the current of the fuel cell or according to the degradation state of the battery.
2. The fuel cell system according to claim 1, wherein, When the current of the fuel cell is equal to or higher than a first predetermined current value for a predetermined time or when degradation of the battery is detected, the SOC lower limit value is increased.
3. The fuel cell system according to claim 1 or 2, wherein, When the maximum value of the current of the fuel cell is equal to or less than a second predetermined current value when the SOC is equal to or less than a predetermined SOC value, the SOC lower limit value is lowered.

Description

Fuel cell system Technical Field The present disclosure relates to a fuel cell system having a fuel cell that receives supply of fuel gas and oxidant gas to generate power. Background Patent document 1 discloses a fuel cell system including a fuel cell that receives a supply of a fuel gas from a fuel gas system and receives a supply of an oxidizing gas from an oxidizing gas system to generate electric power. Prior art literature Patent literature Patent document 1 Japanese patent laid-open No. 2022-185247 Disclosure of Invention Problems to be solved by the invention In a fuel cell system having no device (e.g., DCDC converter) that converts the voltage of the fuel cell (i.e., the voltage of the electric power generated by the fuel cell), the current of the fuel cell (i.e., the current of the electric power generated by the fuel cell) and the voltage depend on the voltage of the battery. Therefore, when the battery is degraded and the voltage of the battery is reduced, the voltage of the fuel cell is also reduced, and the current of the fuel cell may become excessive. Then, there is a possibility that a problem such as degradation due to excessive current application to the fuel cell may occur. Here, patent document 1 does not disclose or suggest any problem in a fuel cell system having no device for converting the voltage of a fuel cell. Accordingly, the present disclosure has been made to solve the above-described problems, and an object of the present disclosure is to provide a fuel cell system capable of suppressing occurrence of a defective condition of a fuel cell accompanying degradation of a battery while forming a simple system configuration without an apparatus for converting a voltage of the fuel cell. Solution for solving the problem In order to solve the above problems, one aspect of the present disclosure is a fuel cell system including a fuel cell and a battery connected to the fuel cell and charged with electric power generated by the fuel cell, wherein the fuel cell system is a system in which a current of the fuel cell depends on a voltage of the battery, and when a state of charge (SOC) of the battery becomes equal to or lower than a SOC lower limit value, control is performed to start electric power generation of the fuel cell, and the SOC lower limit value is changed according to the current of the fuel cell or according to a degradation state of the battery. According to this aspect, the fuel cell system can be formed into a simple system configuration without a device for converting the voltage of the fuel cell supplied to the battery. In addition, when the current of the fuel cell becomes excessive or when the battery is deteriorated, the lower limit value of the SOC, which is the threshold value at which the power generation of the fuel cell starts, can be changed, and the chance of performing the power generation of the fuel cell can be reduced. Therefore, it is possible to suppress occurrence of a defective condition of the fuel cell, such as degradation due to excessive current application to the fuel cell, accompanied by degradation of the battery, while forming a simple system configuration without a device for converting the voltage of the fuel cell. In the above aspect, it is preferable that the SOC lower limit value is increased when the state in which the current of the fuel cell is equal to or higher than the first predetermined current value continues for a predetermined time or when degradation of the battery is detected. According to this aspect, when the state in which the current of the fuel cell is excessive continues for a predetermined time or when degradation of the battery is confirmed, the lower limit value of the SOC, which is the threshold for starting the power generation of the fuel cell, can be increased, and the chance of performing the power generation of the fuel cell can be reduced. Therefore, the occurrence of the defective condition of the fuel cell associated with the deterioration of the battery can be more reliably suppressed. In the above aspect, it is preferable that the SOC lower limit value is lowered when a maximum value of the current of the fuel cell is equal to or less than a second predetermined current value when the SOC is equal to or less than a predetermined SOC value. According to this aspect, when the possibility that the current of the fuel cell becomes excessive is small, the opportunity to generate power of the fuel cell can be increased, and the SOC of the battery can be sufficiently ensured. Effects of the invention According to the fuel cell system of the present disclosure, it is possible to suppress occurrence of a defective condition of the fuel cell accompanied by degradation of the battery while forming a simple system configuration without an apparatus for converting the voltage of the fuel cell. Drawings Fig. 1 is a structural diagram of a fuel cell system according to the present embodiment. Fig. 2 is a diagram showing