US-20260128337-A1 - FUEL CELL SYSTEM

Abstract

A fuel cell system includes three FC stacks connected in parallel, a single battery to which all the FC stacks, and a controller, but no DC-DC converter. The controller is configured to simultaneously measure the FC currents of the three FC stacks. The controller controls power generation of the three FC stacks based on differences between the simultaneously measured FC currents.

Inventors

• Daisaku Asanuma

Assignees

• AISAN KOGYO KABUSHIKI KAISHA

Dates

Publication Date

20260507

Application Date

20251008

Priority Date

20241107

Claims (5)

1. 1 . A fuel cell system comprising: a plurality of fuel cells connected in parallel; a single battery to which all the plurality of fuel cells are connected, wherein the fuel system does not include a DC-DC converter, wherein the fuel cell system further comprises a controller for controlling power generation of each of the plurality of fuel cells, and the controller is configured to simultaneously measure currents of the plurality of fuel cells, and control the power generation of each of the fuel cells based on differences in current measurement values between the fuel cells simultaneously measured.
2. 2 . The fuel cell system according to claim 1 , wherein the controller learns the current measurement values simultaneously measured, preferentially causes the fuel cell having a high current measurement value among the learned current measurement values to generate power, and changes a number of the fuel cells caused to generate power according to a required output power of the fuel cell system.
3. 3 . The fuel cell system according to claim 2 , wherein output powers of the plurality of fuel cells are set to be equal to each other, a maximum required output power of the fuel cell system is set to be satisfied by power generation of N fuel cells among the plurality of fuel cells, and a total number of the plurality of fuel cells is set to N+1 or more, and the controller uses the N fuel cells for power generation, which corresponds to N higher current measurement values in descending order among the learned current measurement values.
4. 4 . The fuel cell system according to claim 1 further comprising an alarm device for notifying deterioration of the fuel cells, wherein when at least one of the current measurement values of the fuel cells is lower than a first current determination value, the controller activates the alarm device to provide a warning notification that the fuel cells may have deteriorated, when at least one of the current measurement values of the fuel cells is lower than a second current determination value that is lower than the first current determination value, the controller activates the alarm device to provide an abnormality notification that the fuel cells are abnormal due to deterioration.
5. 5 . The fuel cell system according to claim 4 , wherein the controller is configured to measure voltage of the battery, and change the first current determination value and the second current determination value according to a measurement value of the voltage.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is based upon and claims the benefit of priority to Japanese Patent Application No. 2024-194995 filed on Nov. 7, 2024, the entire contents of which are incorporated herein by reference. BACKGROUND Technical Field The disclosure relates to a fuel cell system including a fuel cell and a battery charged with electric power generated by the fuel cell. Related Art Conventionally, for example, a power generation apparatus disclosed in Japanese unexamined patent application publication No. 2005-294190 (JP 2005-294190A) has been known. This apparatus includes a plurality of fuel cells connected in parallel, a single secondary battery (a battery) to which all the fuel cells are connected, a load device, and a controller, and is configured as a DC-DC converter-less apparatus. The controller controls activation and stop of the fuel cells and the battery based on the load and the activation time of the load device and the fuel cells. SUMMARY Technical Problems The power generation apparatus disclosed in JP 2005-294190A configured as the DC-DC converter-less apparatus can thus have a simplified structure; however, the fuel cells may deteriorate to different degrees from each other. Here, if the fuel cells are activated without accounting for the differences in deterioration degree, the durability of a fuel cell with a larger deterioration degree than other fuel cells rapidly decreases, resulting in a decline in the durability of the entire power generation apparatus. The disclosure has been made to address the above problems and has a purpose to provide a fuel cell system including a plurality of fuel cells and a battery, and no DC-DC converter, and configured to suppress deterioration of the fuel cells and hence suppress a decline in the durability of the fuel cell system. Means of Solving the Problems To achieve the above-mentioned purpose, one aspect of the disclosure provides a fuel cell system including: a plurality of fuel cells connected in parallel; a single battery to which all the plurality of fuel cells are connected, wherein the fuel system does not include a DC-DC converter, wherein the fuel cell system further comprises a controller for controlling power generation of each of the plurality of fuel cells, and the controller is configured to simultaneously measure currents of the plurality of fuel cells, and control the power generation of each of the fuel cells based on differences in current measurement values between the fuel cells simultaneously measured. According to the above-described configuration, the controller simultaneously measures the currents of the plurality of fuel cells and controls power generation of each of the fuel cells based on differences between the simultaneously measured current values of the fuel cells. Thus, the fuel cell system configured as above can use the fuel cell or fuel cells, which have higher current measurement values and have deteriorated less, for power generation, while avoiding the use of the fuel cell or fuel cells, which have lower current measurement values and may have deteriorated, for power generation. It is therefore possible to suppress the deterioration of each of the fuel cells and further suppress the durability decline of the entire fuel cell system. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of a fuel cell system in a first embodiment; FIG. 2 is a schematic diagram showing a first FC stack and its related configurations in the first embodiment; FIG. 3 is a graph showing one example of (A) a relationship between FC current and FC voltage and (B) a relationship between battery current and battery voltage, when no electric power is consumed by a motor in the first embodiment; FIG. 4 is a graph showing one example of (A) a relationship between FC current and FC voltage of each of FC stacks that differ in deterioration degree and (B) a relationship between battery current and battery voltage, when no power is consumed by a motor in the first embodiment; FIG. 5 is a flowchart showing one example of contents of a power generation control for three FC stacks in the first embodiment; FIG. 6 is a determination value map defining warning determination value and abnormality determination value of FC current with respect to battery voltage in the first embodiment; and FIG. 7 is a flowchart showing one example of contents of a power generation control for three FC stacks in a second embodiment. DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS First Embodiment A first embodiment of a fuel cell system of the disclosure, applied to a fuel cell system to be mounted in an electric vehicle, will be described below in detail, referring to the accompanying drawings. The configuration of a fuel cell system in the first embodiment will be described below. FIG. 1 is a schematic configuration diagram showing the fuel cell system in the first embodiment. This fuel cell system 1 is confi