US-12620609-B2 - Method for controlling fuel cell system, fuel cell system, and fuel cell vehicle
Abstract
By processing circuitry executing a program recorded in a storage unit, a control method for a fuel cell system includes calculating a load output and calculating a maximum output, comparing the load output with the maximum output, and controlling, in a case that the load output exceeds the maximum output, the fuel cell system to decrease a power storage output used by a load, by increasing a power generation output.
Inventors
- Kenichi Shimizu
- Kenta Suzuki
Assignees
- HONDA MOTOR CO., LTD.
Dates
- Publication Date
- 20260505
- Application Date
- 20221121
- Priority Date
- 20211129
Claims (3)
- 1 . A control method for a fuel cell system, the fuel cell system comprising: a fuel cell configured to generate power generation voltage; an electrical power storage device configured to generate power storage voltage; a load including a motor and an inverter including AC terminals connected to the motor and DC terminals connected to the electrical power storage device; a boost converter including input terminals connected to the fuel cell and output terminals connected to each of the electrical power storage device and the DC terminals of the inverter; a memory; and processing circuitry configured to execute a program recorded in the memory, by the processing circuitry executing the program recorded in the memory, the method comprising: calculating a load output that is electric power required to drive the load, and calculating a maximum output that is maximum electric power that is configured to be supplied from the electrical power storage device to the load; comparing the load output with the maximum output; and controlling, in a case that the load output exceeds the maximum output, the fuel cell system to increase a power generation output, which is electric power supplied from the fuel cell to the load via the boost converter, and to decrease a power storage output used by the load, wherein in the controlling, upon detecting that the maximum output has reached the load output, the power generation output that has been increased is held to an increased level.
- 2 . A fuel cell system comprising: a fuel cell configured to generate power generation voltage; an electrical power storage device configured to generate power storage voltage; a load including a motor and an inverter including AC terminals connected to the motor and DC terminals connected to the electrical power storage device; a boost converter including input terminals connected to the fuel cell and output terminals connected to each of the electrical power storage device and the DC terminals of the inverter; a memory; and processing circuitry configured to execute a program recorded in the memory, by the processing circuitry executing the program recorded in the memory, the system: calculates a load output that is electric power required to drive the load, and calculating a maximum output that is maximum electric power that is configured to be supplied from the electrical power storage device to the load; compares the load output with the maximum output; and controls, in a case that the load output exceeds the maximum output, the fuel cell system to increase a power generation output, which is electric power supplied from the fuel cell to the load via the boost converter, and to decrease a power storage output used by the load; and holds the power generation output to an increased level when the maximum output reaches the load output.
- 3 . A fuel cell vehicle in which a fuel cell system is mounted, wherein the fuel cell system comprises: a fuel cell configured to generate power generation voltage; an electrical power storage device configured to generate power storage voltage; a load including a motor and an inverter including AC terminals connected to the motor and DC terminals connected to the electrical power storage device; a boost converter including input terminals connected to the fuel cell and output terminals connected to each of the electrical power storage device and the DC terminals of the inverter; a memory; and processing circuitry configured to execute a program recorded in the memory, by the processing circuitry executing the program recorded in the memory, the system: calculates a load output that is electric power required to drive the load, and calculating a maximum output that is maximum electric power that is configured to be supplied from the electrical power storage device to the load; compares the load output with the maximum output; and controls, in a case that the load output exceeds the maximum output, the fuel cell system to increase a power generation output, which is electric power supplied from the fuel cell to the load via the boost converter, and to decrease a power storage output used by the load; and holds the power generation output to an increased level when the maximum output reaches the load output, and wherein the motor is used as a traveling motor.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2021-192618 filed on Nov. 29, 2021, the contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a method of controlling a fuel cell system including a motor driven by an output of a fuel cell and an output of an electrical power storage device, a fuel cell system, and a fuel cell vehicle. Description of the Related Art JP 2017-051042 A discloses a fuel cell system in which a motor is driven by an output of a fuel cell (electric power generation output) and an output of an electrical power storage device (electrical power storage output), and a fuel cell vehicle equipped with the fuel cell system. This fuel cell system can make maximum use of the combined output of the electric power generation output and the electrical power storage output. This fuel cell system includes a converter for the fuel cell and a converter for the electrical power storage device. The converter for the fuel cell converts a low-voltage electric power generation output into a high-voltage electric power generation output. The converter for the electrical power storage device converts a low-voltage electrical power storage output into a high-voltage electrical power storage output. A controller of the fuel cell system adjusts the elevating or boosting ratio of both converters so that the output voltage (power generation voltage) of the fuel cell does not exceed the output voltage (power storage voltage) of the electrical power storage device. SUMMARY OF THE INVENTION In the fuel cell system, cost reduction is an important problem. For example, by eliminating a converter for the electrical power storage device, the cost of the fuel cell system is reduced. In the fuel cell system of JP 2017-051042 A, if the converter for the electrical power storage device is eliminated, an output terminal of the converter for the fuel cell and the electrical power storage device are directly connected. According to this structure, the output of the electrical power storage device is directly supplied to a motor. Therefore, when the voltage of the electrical power storage device decreases, the electric power that can be supplied to the motor also decreases. For example, it is assumed that a driver steps on an accelerator pedal in a state where the electric power that can be supplied to the motor is reduced. In this case, the electrical power storage device cannot supply sufficient electric power to the motor. Therefore, the fuel cell system cannot accelerate the vehicle as requested by the driver. An object of the present invention is to solve the aforementioned problem. A first aspect of the present invention is a control method for a fuel cell system. The fuel cell system includes a fuel cell configured to generate power generation voltage, an electrical power storage device configured to generate power storage voltage, a load including a motor and an inverter including AC terminals connected to the motor and DC terminals connected to the electrical power storage device, a boost converter including input terminals connected to the fuel cell and output terminals connected to each of the electrical power storage device and the DC terminals of the inverter, a memory, and processing circuitry configured to execute a program recorded in the memory. By the processing circuitry executing the program recorded in the memory, the method includes calculating a load output that is electric power required to drive the load, and calculating a maximum output that is maximum electric power that is configured to be supplied from the electrical power storage device to the load, comparing the load output with the maximum output; and controlling, in a case that the load output exceeds the maximum output, the fuel cell system to decrease a power storage output used by the load, by increasing a power generation output, which is electric power supplied from the fuel cell to the load via the boost converter. A second aspect of the present invention is a fuel cell system including a fuel cell configured to generate power generation voltage, an electrical power storage device configured to generate power storage voltage, a load including a motor and an inverter including AC terminals connected to the motor and DC terminals connected to the electrical power storage device, a boost converter including input terminals connected to the fuel cell and output terminals connected to each of the electrical power storage device and the DC terminals of the inverter, a memory, and processing circuitry configured to execute a program recorded in the memory. By the processing circuitry executing the program recorded in the memory, the system calculates a load output that is electric power required to drive the load, and calculating a maximum output that is maximum ele