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

Abstract

According to the present invention, a main control device determines a control order for starting or stopping a plurality of fuel cell modules. At a control time point for starting or stopping the plurality of fuel cell modules, the main control device starts or stops the plurality of fuel cell modules in an order different from the control order at the previous control time point.

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. 2023-203155, 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 powered by electricity. Therefore, a fuel cell system needs to be equipped with a power storage device that stores power at startup. However, fuel cells can deteriorate over time. When a fuel cell system is equipped with multiple fuel cell modules, the degree of deterioration of the multiple fuel cells can vary depending on the operating time of each fuel cell module. For this reason, there is a demand for uniform deterioration of the multiple fuel cells.

[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 suppresses variations in the degree of deterioration of multiple fuel cell modules in a work machine equipped with multiple fuel cell modules.

[0006] According to one aspect of the present disclosure, a work machine is provided with a work implement, the work machine includes a fuel cell system supported on a body of the work machine and including a plurality of fuel cell modules, and a main control device, wherein at a control point in time for starting or stopping the plurality of fuel cell modules, the main control device starts or stops the plurality of fuel cell modules in an order different from the control order at the previous control point in time.

[0007] According to the above aspect, as one example, the work machine can suppress variations in the degree of deterioration of a plurality of fuel cell modules.

[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 the 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 the first embodiment. Fig. 4 is a flowchart showing control at the time of start-up of a work machine according to a first embodiment. Fig. 5 is a flowchart showing control at the time of start-up of a work machine according to a second embodiment. Fig. 6 is a schematic block diagram showing the configuration of a computer according to the 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 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 unit 145 reads out control order data indicating the previous control order of the fuel cell module 21 from the internal storage (step S2). In the initial state, the internal storage stores control order data in which an initial control order is recorded. The main control unit 145 rotates the control order indicated by the read control order data to update the control order data (step S3). For example, in a work machine 1 having four fuel cell modules A-D, if the control order indicated by the control order data read out in step S2 (the control order at the first control point in time) is A, B, C, D, the main control unit 145 changes the next control order (the control order at the second control point in time) to B, C, D, A, and updates the control order data.

[0029] The main control device 145 determines the fuel cell module 21 to be started up from among the plurality of fuel cell modules 21 in accordance with the updated control order data (step S4). The main control device 145 outputs a start-up command to the fuel cell control device 214 of the fuel cell module 21 determined in step S4 (step S5). Upon receiving the start-up command, the fuel cell control device 214 of the fuel cell module 21 to be started up drives the auxiliary device 213 with power from bus B. When hydrogen and oxygen are supplied to the fuel cell 211 of the fuel cell module 21 to be started up by driving the auxiliary device 213, the fuel cell 211 reacts the hydrogen and oxygen to generate water and electricity.

[0030] The main controller 145 detects the startup of the fuel cell module 21 to be started (step S6). Specifically, the fuel cell controller 214 of the fuel cell module 21 to be started monitors the state of the fuel cell 211 and outputs data indicating the state of the fuel cell 211. The state of the fuel cell 211 includes states such as stopped and startup complete. The data indicating the startup 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 fuel cell module 21 to be started and detects the state of the fuel cell 211. The main controller 145 detects the startup of the fuel cell 211 based on the data from the fuel cell controller 214 of the fuel cell module 21 to be started.

[0031] When the activation of the fuel cell 211 of the fuel cell module 21 to be activated is detected, the main controller 145 outputs a command signal to the fuel cell controller 214 of the fuel cell module 21 to be activated to supply a predetermined power to the bus B (step S7). Based on the command signal from the main controller 145, the fuel cell controller 214 of the fuel cell module 21 to be activated causes the power converter 212 to supply the power generated by the fuel cell 211 to the bus B (step S8).

[0032] Based on the control order data updated in step S3, the main control unit 145 determines whether there is a fuel cell module 21 that should be started next (step S9). If there is a fuel cell module 21 that should be started next (step S9: YES), the main control unit 145 returns to step S5 and determines the next fuel cell module 21 to be started as the one to be started. If there is no fuel cell module 21 that should be started next (step S9: NO), that is, if all fuel cell modules 21 have been started, the main control unit 145 ends the start-up process.

[0033] 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.

[0034] Thereafter, when the operator operates the start operation switch 143 to end operation of the work machine 1, the main control device 145 performs processing to stop each fuel cell module 21. The fuel cell control device 214 of each fuel cell module 21 causes the fuel cell 211 to continue generating power until the remaining fuel in the fuel cell 211 is used up. The power converter 222 of the power storage device module 22 stores the power supplied from each fuel cell module 21 in the power storage device 221. At this time, the main control device 145 may shut down the multiple fuel cell modules 21 one by one in sequence, as with startup. When shutting down the multiple fuel cell modules 21 one by one in sequence, the main control device 145 shuts down the fuel cell modules 21 in the same order as the control order. This makes it possible to reduce variations in the operating times of the multiple fuel cell modules 21.

[0035] <<Actions and Effects>> In this way, the main control device 145 according to the first embodiment functions as follows. The main control device 145 determines the control order of the multiple fuel cells 211. At the start-up time of the multiple fuel cells 211, the main control device 145 starts up the multiple fuel cells 211 in the determined control order. The main control device 145 determines the control order so that the control order at the first start-up time is different from the control order at the second start-up time. If the fuel cells 211 were started up in the same control order every time, a difference would arise in the cumulative load between the fuel cell 211 that starts up first and the fuel cell 211 that starts up last, resulting in relatively rapid deterioration of the fuel cell 211 that starts up first. In contrast, according to the first embodiment, by varying the control order, the progression of deterioration of the fuel cells can be leveled out.

[0036] The main control device 145 according to the first embodiment changes the control order every time the fuel cell module 21 is started up, but this is not limited to this. For example, the main control device 145 according to other embodiments may change the control order every time a certain number of starts are performed.

[0037] Second Embodiment The main control device 145 according to the first embodiment rotates the control order so that the control order is different each time. However, because the load on the work machine 1 varies with each use, even if the control order is rotated, there is a possibility that the degree of deterioration of each fuel cell module 21 will not be uniform. The main control device 145 according to the second embodiment calculates the degree of deterioration of the fuel cell modules 21 and determines the control order of the fuel cell modules 21 according to the degree of deterioration.

[0038] <<Control at Start-Up of Work Machine 1>> Figure 5 is a flowchart showing control at start-up of a work machine 1 according to the second embodiment. The main control device 145 according to the second embodiment executes steps S21 and S22 shown below, instead of steps S2 and S3 of the first embodiment. When the voltage of the bus bar B reaches or exceeds a predetermined voltage value through control of the power converter 222 of the power storage device module 22, the main control device 145 acquires data indicating the degree of deterioration of each fuel cell 211 from the fuel cell control device 214 of each fuel cell module 21 (step S21). The fuel cell control device 214 has the function of calculating the degree of deterioration of the corresponding fuel cell 211 from the time series of current and voltage values ​​output by that fuel cell 211, as well as other operating information.

[0039] The main control device 145 determines the control order of the multiple fuel cell modules 21 based on the data indicating the degree of deterioration acquired from each fuel cell module 21 (step S22). The main control device 145 determines the control order so that the fuel cell 211 with the highest degree of deterioration among the multiple fuel cells 211 is started last. For example, in a work machine 1 having four fuel cell modules A-D, if the degree of deterioration of fuel cell A is 1.0%, the degree of deterioration of fuel cell B is 0.5%, the degree of deterioration of fuel cell C is 1.5%, and the degree of deterioration of fuel cell D is 0.2%, the main control device 145 determines the next control order (start-up order) to be D, B, A, C. The main control device 145 may also determine the control order (start-up order) in ascending order of the degree of deterioration.

[0040] The main control device 145 may also shut down the multiple fuel cell modules 21 one by one in sequence. Even when shutting down the multiple fuel cell modules 21 one by one in sequence, the main control device 145 determines the control order for shutting down the fuel cell modules 21 based on the degree of deterioration of the fuel cells 211. The main control device 145 determines the start-up order so that the fuel cell 211 with the highest degree of deterioration among the multiple fuel cells 211 is shut down first. For example, in a work machine 1 having four fuel cell modules A-D, if the degree of deterioration of fuel cell A is 1.0%, the degree of deterioration of fuel cell B is 0.5%, the degree of deterioration of fuel cell C is 1.5%, and the degree of deterioration of fuel cell D is 0.2%, the main control device 145 determines the next control order (shutdown order) to be C, A, B, D. The main control device 145 may also determine the control order (shutdown order) in descending order of the degree of deterioration.

[0041] In this way, the main control device 145 according to the second embodiment identifies the degree of degradation of each of the multiple fuel cells 211 and determines the control order so that the fuel cell 211 with the highest degree of degradation is the last to be started or the first to be stopped. This shortens the operating time of the fuel cell 211 with the highest degree of degradation, thereby preventing further deterioration.

[0042] 6 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] Furthermore, the main control device 145 according to other embodiments may randomly determine the control order of the multiple fuel cell modules 21. Furthermore, the main control device 145 according to other embodiments may determine the control order so as to rotate the fuel cell module 21 to be started up first and the fuel cell module 21 to be started up last. For example, in a work machine 1 having four fuel cell modules A-D, if the previous control order was A, B, C, D, the next control order may be determined to be D, B, C, A. Furthermore, the main control device 145 according to other embodiments may randomly determine the control order when the multiple fuel cell modules 21 have been started or stopped a predetermined number of times. For example, in a work machine 1 having four fuel cell modules A-D, if the fuel cell modules have been started up a predetermined number of times in the control order A, B, C, D, the next control order may be determined to be B, C, D, A. In either case, the control order (start-up order or stop order) at two consecutive different control points (start-up points or stop points) will be different from each other.

[0050] 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.

[0051] The main control device 145 according to another embodiment may start up the plurality of fuel cell modules 21 according to a control order at the time of startup, and may stop the plurality of fuel cell modules simultaneously at the time of shutdown. Furthermore, the main control device 145 according to another embodiment may start up the plurality of fuel cell modules 21 simultaneously at the time of startup, and may stop the plurality of fuel cell modules according to a control order at the time of shutdown.

[0052] According to the present disclosure, as one example, a work machine can suppress variations in the degree of deterioration of a plurality of fuel cell modules.

[0053] 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 supported on a body of the work machine and equipped with a plurality of fuel cell modules; and a main control device, wherein, at a control point in time for starting or stopping the plurality of fuel cell modules, the main control device starts or stops the plurality of fuel cell modules in an order different from the control order at the previous control point in time.

2. A work machine as described in claim 1, wherein the main control device starts or stops the multiple fuel cell modules in an order different from the control order at the time of the previous control based on the state of each of the multiple fuel cell modules.

3. The work machine as described in claim 1, wherein the main control device identifies the degree of deterioration of each of the plurality of fuel cell modules, and starts or stops the plurality of fuel cell modules in an order different from the control order at the time of the previous control, so that the fuel cell module with the highest degree of deterioration is started last or stopped first.

4. A work machine equipped with a working implement, comprising: a fuel cell system supported on a body of the work machine and equipped with a plurality of fuel cell modules; and a main control device, wherein when the work machine is started up or operation is terminated, the main control device starts up or stops a fuel cell module among the plurality of fuel cell modules, different from the fuel cell module that was started up or stopped first, at the next start up or stop.

5. 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 a main control device, wherein at a control point in time for starting or stopping the plurality of fuel cell modules, the main control device starts or stops the plurality of fuel cell modules in an order different from the control order at the previous control point in time.

6. A method for controlling a fuel cell system having a plurality of fuel cell modules that generate power for driving a work machine having a work implement, the method comprising, at a control point in time at which the plurality of fuel cell modules are started or stopped, starting or stopping the plurality of fuel cell modules in an order different from the control order at the previous control point in time.

Images