Work machine, fuel cell system, and method for controlling fuel cell system

Abstract

According to the present invention, upon receiving a command signal for starting a work machine, a main control device outputs an activation command to a first fuel cell module among a plurality of fuel cell modules. Upon detecting the activation of the first fuel cell module, the main control device outputs an activation command to a second fuel cell module, which is different from the first fuel cell module, among the plurality of fuel cell modules.

Description

Work machine, fuel cell system and method for controlling a fuel cell system

[0001] This disclosure relates to a work machine, a fuel cell system, and a method for controlling a fuel cell system. This application claims priority to Japanese Patent Application No. 2023-203174, filed November 30, 2023, the contents of which are incorporated herein by reference.

[0002] In the technical field related to work machines, an extra-large truck equipped with a fuel cell system including multiple fuel cell modules, as disclosed in Patent Document 1, is known. A fuel cell generates electrical energy through a chemical reaction between hydrogen and oxygen. The hydrogen fuel is supplied from a tank filled with hydrogen gas. Oxygen is supplied from the atmosphere. Therefore, the fuel cell is equipped with auxiliary devices such as a fuel pump and an air compressor to operate the fuel cell.

[0003] U.S. Patent Application No. 2022 / 0173459

[0004] The auxiliary devices required to operate a fuel cell are driven by electricity. Therefore, a fuel cell system needs to be equipped with a power storage device to store power during startup. When a fuel cell system is equipped with multiple fuel cells, the more fuel cells there are, the more power required for startup, so a large-capacity power storage device is required. However, there is a demand for smaller power storage devices to be installed in fuel cell systems.

[0005] An example of an objective of the present disclosure is to provide a work machine, a fuel cell system, and a method for controlling a fuel cell system that can reduce the amount of power that needs to be stored for startup in a work machine equipped with multiple fuel cells.

[0006] According to one aspect of the present disclosure, a work machine is provided with a work implement, and includes a fuel cell system supported on a body of the work machine and including a plurality of fuel cell modules connected to a bus, and a main control device. When the main control device receives a command signal to start the work machine, it outputs a startup command to a first fuel cell module of the plurality of fuel cell modules. When the main control device detects the startup of the first fuel cell module, it outputs a startup command to a second fuel cell module of the plurality of fuel cell modules that is different from the first fuel cell module.

[0007] According to the above aspect, as one example, the work machine can reduce the amount of electric power that needs to be stored for startup.

[0008] Fig. 1 is a schematic diagram showing the configuration of a work machine according to a first embodiment. Fig. 2 is a schematic diagram showing the configuration of a cab of a work machine according to a first embodiment. Fig. 3 is a schematic block diagram showing the configuration of a fuel cell system and a drive system of a work machine according to a first embodiment. Fig. 4 is a flowchart showing control at the start-up of a work machine according to a first embodiment. Fig. 5 is a schematic block diagram showing the configuration of a computer according to a first embodiment.

[0009] First Embodiment Configuration of Work Machine 1 Figure 1 is a schematic diagram showing the configuration of a work machine 1 according to the first embodiment. The work machine 1 according to the first embodiment is, for example, a hydraulic excavator. The work machine 1 includes a traveling body 110, a revolving body 120, a work implement 130, a cab 140, and a main control device 145. The work machine 1, which is a hydraulic excavator, excavates earth and sand and levels the ground at a work site or the like. The traveling body 110 and the revolving body 120 form a vehicle body.

[0010] The running body 110 supports the work machine 1 so that it can travel. The running body 110 has a pair of left and right tracks. The work machine 1 moves forward, turns, or moves backward by rotation of the pair of tracks. The rotating body 120 is supported on the running body 110 so that it can turn around a turning center. The rotating body 120 supports the work implement 130, the operator's cab 140, the machine room 150, and the fuel cell system 20.

[0011] The cab 140 is where an operator of the work machine 1 gets in and operates and pilots the work machine 1. The cab 140 is located, for example, on the left side of the front end of the rotating body 120. A main control device 145 is mounted in the cab 140 of the work machine 1.

[0012] The fuel cell system 20, which will be described later, is disposed in the machinery room 150. The machinery room 150 is disposed, for example, behind the operator's cab 140. The machinery room 150 forms a space in which the fuel cell system 20 is disposed.

[0013] The work implement 130 is operably supported on the body of the work machine 1. The work implement 130 includes a boom 131, an arm 132, and an attachment 133 which is a working tool. The attachment 133 is an example of a working tool. In the example shown in FIG. 1 , the attachment 133 is a bucket. The base end of the boom 131 is rotatably attached to the front end of the rotating unit 120. The base end of the arm 132 is rotatably attached to the tip of the boom 131. The attachment 133 is rotatably attached to the tip of the arm 132.

[0014] The work machine 1 is equipped with a plurality of actuators for driving the work implement 130. The plurality of actuators includes, for example, a boom cylinder 131C, an arm cylinder 132C, and an attachment cylinder 133C.

[0015] The boom cylinder 131C is a hydraulic cylinder for driving the boom 131. The base end of the boom cylinder 131C is attached to the revolving unit 120. The tip end of the boom cylinder 131C is attached to the boom 131. The arm cylinder 132C is a hydraulic cylinder for driving the arm 132. The base end of the arm cylinder 132C is attached to the boom 131. The tip end of the arm cylinder 132C is attached to the arm 132. The attachment cylinder 133C is a hydraulic cylinder for driving the attachment 133. The base end of the attachment cylinder 133C is attached to the arm 132. The tip end of the attachment cylinder 133C is attached to the attachment 133.

[0016] <Configuration of the Operator's Cabin> FIG. 2 is a schematic diagram showing the configuration of the operator's cab 140 of the work machine 1 according to the first embodiment.

[0017] 2, the driver's cab 140 is provided with a driver's seat 141, a left operation lever 142LO, a right operation lever 142RO, a left foot pedal 142LF, a right foot pedal 142RF, a left travel lever 142LT, a right travel lever 142RT, and a start operation switch 143. The left operation lever 142LO and the right operation lever 142RO are disposed on the left and right sides of the driver's seat 141 in the driver's cab 140. The left foot pedal 142LF and the right foot pedal 142RF are disposed on the floor in front of the driver's seat 141 in the driver's cab 140.

[0018] The left operating lever 142LO, located on the left side facing the front of the cab, is an operating device for performing the rotating operation of the revolving body 120 and the excavation / dumping operation of the arm 132. The right operating lever 142RO, located on the right side facing the front of the cab, is an operating device for performing the excavation / dumping operation of the attachment 133 and the raising / lowering operation of the boom 131.

[0019] Furthermore, the left travel lever 142LT and the right travel lever 142RT are operating devices for controlling the operation of the running body 110, i.e., for controlling the travel of the work machine 1. The left travel lever 142LT, located on the left side as you face the front of the cab, corresponds to the rotational drive of the left crawler of the running body 110. The right travel lever 142RT, located on the right side as you face the front of the cab, corresponds to the rotational drive of the right crawler of the running body 110. The left foot pedal 142LF and the right foot pedal 142RF are linked to the left travel lever 142LT and the right travel lever 142RT, respectively, and travel can also be controlled by the left foot pedal 142LF and the right foot pedal 142RF.

[0020] 3 is a schematic block diagram showing the configuration of the fuel cell system 20 and drive system 30 of the work machine 1 according to the first embodiment. The work machine 1 is equipped with the fuel cell system 20 and the drive system 30. The fuel cell system 20 generates electric power for driving the work machine 1. The fuel cell system 20 generates electric power for driving the drive system 30. The electric power generated by the fuel cell system 20 is output to the drive system 30 via a bus line B. The drive system 30 drives the work implement 130 and the traveling body 110 using the electric power generated by the fuel cell system 20.

[0021] The fuel cell system 20 includes a plurality of fuel cell modules 21 and a power storage device module 22 connected in parallel to a bus B.

[0022] Each fuel cell module 21 includes a fuel cell 211, a power converter 212, auxiliary equipment 213, and a fuel cell control device 214. The fuel cell 211 generates power by causing an electrochemical reaction between hydrogen and oxygen. The power converter 212 is, for example, a DC-DC converter, and is configured to control the power generated by the fuel cell 211. The power converter 212 converts the power generated by the fuel cell 211 and supplies it to the bus B. The auxiliary equipment 213 is a device for operating the fuel cell 211. The fuel cell module 21 includes, as the auxiliary equipment 213, a hydrogen pump for supplying hydrogen gas to the fuel cell 211, an air compressor for generating compressed air to be supplied to the fuel cell 211, and a water pump for supplying cooling water to cool the fuel cell 211. The fuel cell control device 214 controls the fuel cell module 21 in accordance with commands from the main control device 145. The fuel cell control device 214 monitors the status of the fuel cell 211 and outputs data indicating the status of the fuel cell 211 to the main control device 145. The fuel cell control device 214 is an example of a monitoring device.

[0023] The power storage device module 22 includes a power storage device 221 and a power converter 222. The power storage device 221 is configured to be able to store or discharge surplus power from the bus B. The power converter 222 is, for example, a DC-DC converter, and controls the input and output of power to and from the power storage device 221. The power converter 222 outputs power from the power storage device 221 in accordance with commands from the main control device 145. The power storage device 221 is, for example, a capacitor.

[0024] The drive system 30 includes a hydraulic drive module 31 and a slewing module 32 .

[0025] The hydraulic drive module 31 includes an inverter 311, an electric motor 312, a hydraulic pump 313, and a hydraulic actuator 314. The inverter 311 converts DC current from a bus B into three-phase AC current and supplies the AC current to the electric motor 312. The electric motor 312 is rotated by the supplied three-phase AC current and drives the hydraulic pump 313. The hydraulic pump 313 discharges hydraulic oil to be supplied to the hydraulic actuator 314. The hydraulic oil discharged from the hydraulic pump 313 is supplied to the hydraulic actuator 314 via a control valve (not shown). The hydraulic actuator 314 is driven by the supplied hydraulic oil. The hydraulic actuator 314 includes a boom cylinder 131C, an arm cylinder 132C, an attachment cylinder 133C, and a traveling motor 134. The rotational force generated by the traveling motor 134 is transmitted to the traveling body 110.

[0026] The swing module 32 includes an inverter 321 and an electric swing motor 322. The inverter 321 converts DC current from the bus B into three-phase AC current and supplies it to the electric swing motor 322. The electric swing motor 322 rotates by the supplied three-phase AC current, causing the swing unit 120 to rotate relative to the traveling unit 110.

[0027] <<Control at Start-Up of Work Machine 1>> Figure 4 is a flowchart showing control at start-up of the work machine 1 according to the first embodiment. When the operator operates the start operation switch 143, the start operation switch 143 outputs a command signal to start the work machine 1 to the main control device 145. The start operation switch 143 is, for example, a switch that outputs a command signal to start the work machine 1 when pressed by the operator. When a command signal to start the work machine 1 is input from the start operation switch 143 to the main control device 145 by operation of the operator, the main control device 145 starts up the fuel cell system 20 in the following procedure. First, the main control device 145 outputs a command signal to the power converter 222 of the power storage device module 22 so as to supply a predetermined amount of power to the bus B (step S1). The predetermined power may be power that is sufficient to drive the auxiliary device 213 of at least one of the plurality of fuel cell modules 21.

[0028] Next, the main control device 145 selects at least one fuel cell module 21 to be activated first from the plurality of fuel cell modules 21 (step S2). Hereinafter, the selected fuel cell module 21 will be referred to as the first fuel cell module. The first fuel cell module may be predetermined, selected randomly by the main control device 145, or selected in a scheduled order so that the total operating time is the same. Note that if the power converter 222 of the power storage device module 22 supplies to the bus line B enough power to drive the auxiliaries 213 of the plurality of fuel cell modules 21, then the plurality of fuel cell modules 21 may be selected as the first fuel cell module.

[0029] The main control device 145 outputs a startup command to the fuel cell control device 214 of the first fuel cell module selected in step S2 (step S3). Upon receiving the startup command, the fuel cell control device 214 of the first fuel cell module drives the auxiliary device 213 with power from bus line B. That is, at this time, the auxiliary device 213 of the first fuel cell module is driven by power supplied from the power storage device 221. When hydrogen and oxygen are supplied to the fuel cell 211 of the first fuel cell module by driving the auxiliary device 213, the fuel cell 211 reacts the hydrogen and oxygen to generate electricity.

[0030] The main controller 145 detects the start-up of the fuel cell 211 of the first fuel cell module (step S4). Specifically, the fuel cell controller 214 of the first fuel cell module monitors the status of the fuel cell 211 and outputs data indicating the status of the fuel cell 211. The status of the fuel cell 211 includes states such as stopped and start-up complete. The data indicating the start-up complete state is an example of a notification indicating that the fuel cell 211 is operating. The main controller 145 receives the data output from the fuel cell controller 214 of the first fuel cell module and detects the status of the fuel cell 211. The main controller 145 detects the start-up of the fuel cell 211 of the first fuel cell module based on the data from the fuel cell controller 214 of the first fuel cell module.

[0031] When the main controller 145 detects activation of the fuel cell 211 of the first fuel cell module, it outputs a command signal to the fuel cell controller 214 of the first fuel cell module to supply a predetermined power to the bus line B (step S5). The predetermined power may be a power that is capable of driving the auxiliary device 213 of at least one fuel cell module 21 out of the plurality of fuel cell modules 21. Based on the command signal from the main controller 145, the fuel cell controller 214 of the first fuel cell module causes the power converter 212 to supply the power generated by the fuel cell 211 to the bus line B.

[0032] Next, the main control device 145 selects at least one fuel cell module 21 to be activated next from among the multiple fuel cell modules 21 that are not activated (step S6). Hereinafter, the fuel cell module 21 selected after the first fuel cell module is referred to as the second fuel cell module. The second fuel cell module is a fuel cell module 21 that is different from the first fuel cell module. The second fuel cell module may be predetermined, may be selected randomly by the main control device 145, or may be selected in a scheduled order so that the total operating time is the same. The main control device 145 selects a second fuel cell module that can drive the auxiliary devices 213 with the power output by the first fuel module that is already operating. If the fuel cell 211 of the first fuel cell module supplies enough power to the bus B to drive the auxiliary devices 213 of the multiple fuel cell modules 21, multiple fuel cell modules 21 may be selected as the second fuel module.

[0033] The main control device 145 outputs a startup command to the fuel cell control device 214 of the second fuel cell module selected in step S6 (step S7). Upon receiving the startup command, the fuel cell control device 214 of the second fuel cell module drives the auxiliary device 213 with power from bus line B. Although the remaining power stored in the power storage device 221 may be depleted, the auxiliary device 213 of the second fuel cell module can be driven by power supplied from the first fuel cell module. When hydrogen and oxygen are supplied to the fuel cell 211 of the second fuel cell module by driving the auxiliary device 213, the fuel cell 211 reacts the hydrogen and oxygen to generate power.

[0034] The main controller 145 detects the start-up of the fuel cell 211 of the second fuel cell module (step S8). Specifically, the fuel cell controller 214 of the second fuel cell module monitors the status of the fuel cell 211 and outputs data indicating the status of the fuel cell 211. The status of the fuel cell 211 includes states such as stopped and start-up complete. The data indicating the start-up complete state is an example of a notification indicating that the fuel cell 211 is operating. The main controller 145 receives the data output from the fuel cell controller 214 of the second fuel cell module and determines the status of the fuel cell 211. The main controller 145 detects the start-up of the fuel cell 211 of the second fuel cell module based on the data from the fuel cell controller 214 of the second fuel cell module.

[0035] When the main control device 145 detects activation of the fuel cell 211 of the second fuel cell module, it outputs a command signal to the fuel cell control device 214 of the second fuel cell module to supply a predetermined amount of power to the bus line B (step S9). Based on the command signal from the main control device 145, the fuel cell control device 214 of the second fuel cell module causes the power converter 212 to supply the power generated by the fuel cell 211 to the bus line B.

[0036] Thereafter, while there is a fuel cell module 21 that is not activated, the main control device 145 drives the auxiliary device 213 of the fuel cell module 21 that is not activated using the power output by the fuel module that is already operating.

[0037] When startup of all fuel cell modules 21 is complete, the main control device 145 permits operation of the work machine 1 in accordance with the operator's operation of the operating device. The main control device 145 accepts the operator's operation of the operating device, and outputs control commands to the inverter 311 of the hydraulic drive module 31 and the inverter 321 of the swing module 32 in accordance with the amount of operation.

[0038] <<Actions and Effects>> As described above, the main control device 145 according to the first embodiment functions as follows. When the main control device 145 receives a command signal to start the fuel cell system 20 while all of the multiple fuel cells 211 are stopped during startup of the work machine 1, it outputs a command signal to drive the auxiliary device 213 of a first fuel cell module among the multiple fuel cell modules 21. When the first fuel cell module is operating, the main control device 145 outputs a command signal to drive the auxiliary device 213 of a second fuel cell module among the multiple fuel cell modules 21. Therefore, it is sufficient for the power storage device 221 to store the power to be supplied to the auxiliary device 213 until startup of at least the first fuel cell module among the multiple fuel cell modules 21 is complete. Therefore, the power storage device 221 does not need to have a capacity sufficient to drive the auxiliary devices 213 of all fuel cell modules 21 during startup. In other words, the fuel cell system 20 according to the first embodiment allows the power storage device 221 to be made smaller. Furthermore, when the power storage device 221 is a capacitor, its capacity relative to its size is smaller than that of a battery, and therefore, by performing the control according to the first embodiment, it is possible to reduce the size of the power storage device 221 provided in the work machine 1. Therefore, the fuel cell system 20 according to the first embodiment can reduce the amount of power that needs to be stored before startup.

[0039] 5 is a schematic block diagram showing the configuration of a computer according to the first embodiment. The computer 90 includes a processor 91, a main memory 92, a storage 93, and an interface 94. The main control device 145 and the fuel cell control device 214 described above are implemented in the computer 90. The operations of the above-described processing units are stored in the storage 93 in the form of a program. The processor 91 reads the program from the storage 93, loads it into the main memory 92, and executes the above-described processing in accordance with the program. The processor 91 also allocates storage areas in the main memory 92 corresponding to the above-described storage units in accordance with the program. Examples of the processor 91 include a CPU (Central Processing Unit), a GPU (Graphic Processing Unit), and a microprocessor.

[0040] The program may be for implementing some of the functions to be performed by the computer 90. For example, the program may be implemented in combination with other programs already stored in storage or in combination with other programs implemented in other devices. In another embodiment, the computer 90 may include a custom large-scale integrated circuit (LSI) such as a programmable logic device (PLD) in addition to or instead of the above configuration. Examples of PLDs include programmable array logic (PAL), generic array logic (GAL), complex programmable logic device (CPLD), and field programmable gate array (FPGA). In this case, some or all of the functions implemented by the processor 91 may be implemented by the integrated circuit. Such an integrated circuit is also an example of a processor. In another embodiment, the computer 90 may be virtualized on one or more computers.

[0041] Examples of storage 93 include a magnetic disk, a magneto-optical disk, an optical disk, and a semiconductor memory. Storage 93 may be an internal medium directly connected to the bus of computer 90, or an external medium connected to computer 90 via interface 94 or a communication line. Furthermore, when this program is distributed to computer 90 via a communication line, computer 90 that receives the program may load the program into main memory 92 and execute the above-described processing. In at least one embodiment, storage 93 is a non-transitory tangible storage medium.

[0042] The program may also be a program for realizing part of the above-described functions. Furthermore, the program may be a so-called differential file (differential program) that realizes the above-described functions in combination with another program already stored in storage 93.

[0043] Other Embodiments Although one embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to that described above, and various design modifications and the like are possible. For example, the main control device 145 according to the embodiment described above may be configured by a single computer, or the configuration of the main control device 145 may be divided into multiple computers that function as the main control device 145 by working together. In this case, some of the computers that make up the main control device 145 may be installed inside the work machine 1, and other computers may be provided external to the work machine 1. The main control device 145 according to the embodiment described above may also have the functionality of the fuel cell control device 214. In this case, each fuel cell module 21 does not need to be equipped with the fuel cell control device 214, and the power converters 212 and auxiliaries 213 of each fuel cell module 21 may operate based on command signals from the main control device 145. The main control device 145 may also function as a monitoring device, having the function of monitoring the status of the fuel cells 211.

[0044] Furthermore, although the work machine 1 according to the embodiment described above is a hydraulic excavator, this is not limiting. For example, the work machine 1 according to other embodiments may be another work machine such as a wheel loader or a dump truck.

[0045] Furthermore, in the above-described embodiment, a capacitor is given as an example of the power storage device 221, but this is not limiting. For example, the power storage device 221 of the work machine 1 according to other embodiments may be a battery.

[0046] In the above-described embodiment, the work machine 1 is described as having two fuel cell modules as shown in Fig. 3, but this is not limiting. The work machine 1 according to other embodiments may be equipped with three or more fuel cell modules.

[0047] Furthermore, in the above-described embodiment, the start operation switch 143 that starts the work machine 1 is a switch that outputs a start signal when pressed by the operator, but this is not limited to this. The start operation switch 143 may, for example, be a key switch that has a key cylinder into which a key can be inserted and is operated by inserting the key into the key cylinder and turning the key from the OFF position to the KEY ON position and then to the START position. The start operation switch 143 may, for example, be a portable operation device carried by the operator, and the operator may operate the portable operation device to establish wireless communication between the portable operation device and the main control device 145, and start of the work machine 1 may be initiated on the condition that communication is established. The portable operation device may, for example, be a remote control key with an embedded electronic chip, or a portable computer device such as a smartphone or personal digital assistant. The start operation switch 143 may, for example, be located in a remote location so that the work machine 1 can be started by remote control.

[0048] According to the present disclosure, as one example, a work machine can reduce the amount of power that needs to be stored for startup.

[0049] 1...Work machine 110...Traveling body 120...Slewing body 130...Work machine 131...Boom 131C...Boom cylinder 132...Arm 132C...Arm cylinder 133...Attachment 133C...Attachment cylinder 134...Travel motor 140...Driver's cab 141...Driver's seat 142LF...Left foot pedal 142LO...Left operation lever 142LT...Left travel lever 142RF...Right foot pedal 142RO...Right operation lever 142RT...Right travel lever 145...Main control device 20...Fuel cell system 21...Fuel cell module 211...Fuel cell 212...Power converter 213...Auxiliary device 214...Fuel cell control device 22...Power storage device module 221...Power storage device 222...Power converter 30...Drive system 31...Hydraulic drive module 311...Inverter 312... Electric motor 313... Hydraulic pump 314... Hydraulic actuator 32... Swing module 321... Inverter 322... Electric swing motor B... Bus bar

Claims

1. A work machine equipped with a working implement, comprising: a fuel cell system equipped with a plurality of fuel cell modules supported on a body of the work machine and connected to a bus; and a main control device, wherein the main control device outputs a startup command to a first fuel cell module of the plurality of fuel cell modules when it receives a command signal to start the work machine, and outputs a startup command to a second fuel cell module, different from the first fuel cell module, of the plurality of fuel cell modules when it detects the startup of the first fuel cell module.

2. A work machine as described in claim 1, further comprising auxiliary devices provided corresponding to each of the plurality of fuel cell modules for operating the corresponding fuel cells, wherein the main control device, when receiving the command signal to start the work machine, outputs a command signal to drive the auxiliary device corresponding to the first fuel cell module, and when detecting the start-up of the first fuel cell module, outputs a command signal to drive the auxiliary device corresponding to the second fuel cell module.

3. A work machine as claimed in claim 1, further comprising: a power storage device connected to the busbar; and a power converter provided between the power storage device and the busbar, wherein when the main control device receives the command signal to start the work machine, the main control device outputs a command signal to the power converter to supply electric power from the power storage device to the busbar.

4. A work machine as described in claim 1, further comprising a monitoring device which outputs data indicating the status of the first fuel cell module, wherein the main control device detects the start-up of the first fuel cell module based on the data output from the monitoring device, and outputs the start-up command to the second fuel cell module when the main control device detects the start-up of the first fuel cell module.

5. The work machine according to claim 3, wherein the power storage device is a capacitor.

6. The work machine according to claim 3, wherein the power storage device is a battery.

7. The work machine according to claim 1, wherein the main control device permits operation of the work machine when start-up of all of the plurality of fuel cell modules has been completed.

8. A fuel cell system that generates electricity to drive a work machine equipped with a working implement, comprising: a plurality of fuel cell modules supported on a body of the work machine and connected to a bus; and a main control device, wherein the main control device outputs a startup command to a first fuel cell module among the plurality of fuel cell modules when it receives a command signal to start the work machine, and outputs a startup command to a second fuel cell module, different from the first fuel cell module, among the plurality of fuel cell modules when it detects the startup of the first fuel cell module.

9. A method for controlling a fuel cell system which is supported on a vehicle body, has a plurality of fuel cell modules connected to a bus, and generates power for driving a work machine having a working implement, the method comprising the steps of: when a command signal to start the work machine is received, outputting a startup command to a first fuel cell module among the plurality of fuel cell modules; and when startup of the first fuel cell module is detected, outputting a startup command to a second fuel cell module, different from the first fuel cell module, among the plurality of fuel cell modules.

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