Control device, fuel cell system, and control method

Abstract

A control device (18) of a fuel cell system (12) including a first fuel cell unit (141) and a second fuel cell unit (142) can execute performance acquisition preparation control for causing the second fuel cell unit to generate power in an idle state until a required output (RP) reaches a predetermined output (Pth), thereby causing a part of the required output to be output, and causing the remainder to be output by the first fuel cell unit, and acquires performance information of the first fuel cell unit when the required output reaches the predetermined output during execution of the performance acquisition preparation control.

Description

Control Device, Fuel Cell System, and Control Method

[0006] ,

[0001] The present disclosure relates to a control device, a fuel cell system, and a control method.

[0002] In recent years, in order for more people to access affordable, reliable, sustainable, and advanced energy, research and development on fuel cells that contribute to energy efficiency have been conducted. For example, Japanese Patent Application Laid-Open No. 2020-031525 discloses a technology related to a fuel cell system. The object of that technology is to ensure the frequency of obtaining accurate output performance of a fuel cell according to Japanese Patent Application Laid-Open No. 2020-031525.

[0003] Recently, better technologies have been desired regarding ensuring the frequency of obtaining accurate output performance of a fuel cell.

[0004] A first aspect of the present disclosure is a control device for a fuel cell system including a first fuel cell unit and a second fuel cell unit, the control device including: a required output acquisition unit that acquires a required output for the entire fuel cell system; an output control unit that controls outputs of the first fuel cell unit and the second fuel cell unit so that the required output is satisfied; and a performance acquisition unit that acquires performance information indicating performance of the first fuel cell unit. Until the required output reaches a predetermined output, the output control unit can execute performance acquisition preparation control in which, by causing the second fuel cell unit to generate power in an idle state to output a part of the required output, the remaining part of the required output excluding the part is output to the first fuel cell unit. When the required output reaches the predetermined output during execution of the performance acquisition preparation control, the performance acquisition unit acquires the performance information.

[0005] A second aspect of the present disclosure is a fuel cell system including the control device according to the first aspect, the first fuel cell unit, and the second fuel cell unit.

[0006] A third aspect of the present disclosure is a control method for a fuel cell system including a first fuel cell unit and a second fuel cell unit, comprising: a request output acquisition step of acquiring request output information indicating a request output which is an output required for the fuel cell system; a performance acquisition preparation control step of performing performance acquisition preparation control in which the second fuel cell unit is made to generate electricity in an idle state until the request output reaches a predetermined output, thereby outputting a portion of the request output, while the remaining portion of the request output is output to the first fuel cell unit; and a performance acquisition step of which is performed when the request output reaches the predetermined output during the execution of the performance acquisition preparation control, and which acquires performance information indicating the performance of the first fuel cell unit.

[0007] Figure 1 is a block diagram of a vehicle according to one embodiment. Figure 2 is a flowchart of a control method according to one embodiment. Figure 3A is a graph illustrating the time progression of the output of the first fuel cell unit when the control method of Figure 2 is executed. Figure 3B is a graph illustrating the time progression of the output of the second fuel cell unit when the control method of Figure 2 is executed. Figure 3C is a graph illustrating the time progression of the requested output when the control method of Figure 2 is executed.

[0008] The performance (output performance) of a fuel cell is more clearly reflected in its output as the output of the fuel cell increases. Therefore, it is preferable to acquire (evaluate) the performance of a fuel cell when its output is relatively high. In this regard, Japanese Patent Publication No. 2020-031525 proposes executing a first power generation control when it is determined that predetermined conditions have been met, and acquiring the output performance of the first fuel cell during the execution of the first power generation control. According to Japanese Patent Publication No. 2020-031525, the first power generation control referred to here is a control that increases the output of the first fuel cell and decreases the output of the second fuel cell compared to when it is determined that the predetermined conditions have not been met.

[0009] However, if the increase in output of the fuel cell subject to performance acquisition begins after certain conditions are met, there is a risk that performance acquisition may be performed before the fuel cell's output has increased sufficiently. Furthermore, there is a risk that the certain conditions may not be met while the fuel cell's output is being increased. For example, due to these circumstances, the frequency of acquiring accurate fuel cell output performance has not always been adequately ensured in the past.

[0010] Based on the preliminary explanation above, one embodiment will be described below. In the following description, the term "program" (computer program, computer software) is also referred to as a "computer program product." A computer program product is not limited to programs stored on a storage medium (recording medium), but also includes programs transmitted, distributed, and downloaded via networks such as the Internet.

[0011] (One Embodiment) Figure 1 is a block diagram of a vehicle 10 according to one embodiment.

[0012] The fuel cell system 12 is installed in a vehicle 10, such as a fuel cell vehicle. The fuel cell system 12 comprises a plurality of fuel cell units 14, a plurality of converter units 16, and a control device 18. The fuel cell system 12 further includes a gas supply circuit that supplies various gases such as anode gas and cathode gas used for power generation to the plurality of fuel cell units 14, a refrigerant circuit that supplies refrigerant to the plurality of fuel cell units 14, etc., but a more detailed explanation of these will be omitted.

[0013] Each of the multiple fuel cell units 14 has a fuel cell. A fuel cell is a device that generates electricity using the various gases described above. The fuel cell unit 14 may have multiple fuel cells. For example, the fuel cell unit 14 may be a fuel cell stack.

[0014] The multiple fuel cell units 14 include a first fuel cell unit 141, which is one fuel cell unit 14, and a second fuel cell unit 142, which is another fuel cell unit 14. Any fuel cell unit 14 that is the subject of performance acquisition (performance evaluation) in this embodiment is identified as the first fuel cell unit 141. All of the multiple fuel cell units 14 other than the first fuel cell unit 141 are identified as the second fuel cell unit 142. Therefore, if the total number of fuel cell units 14 is three or more, two or more second fuel cell units 142 may be identified.

[0015] The performance (output performance) of the fuel cell unit 14 indicates the degree of degradation of the fuel cell unit 14. The performance of the fuel cell unit 14 is evaluated, for example, based on the characteristics (IV characteristics) between the output voltage and output current of the fuel cell unit 14.

[0016] Each of the multiple converter units 16 has a DC-DC converter. Multiple converter units 16 are arranged corresponding to each of the multiple fuel cell units 14. For example, the multiple converter units 16 include a first converter unit 161 corresponding to a first fuel cell unit 141 and a second converter unit 162 corresponding to a second fuel cell unit 142. The converter unit 16 adjusts the output (power, DC current) of the corresponding fuel cell unit 14. The output of the fuel cell unit 14 adjusted by the converter unit 16 is supplied to an electric machine, such as a rotating electric machine, provided in the vehicle 10, via an inverter (not shown), but is not limited to this. The output of the fuel cell unit 14 adjusted by the converter unit 16 may be supplied to a storage battery, for example.

[0017] The control device 18 is an electronic device responsible for controlling the output of the multiple fuel cell units 14 and acquiring the performance of the first fuel cell unit 141. For example, a computer such as an ECU (Electronic Control Unit) is included in the control device 18. As shown in Figure 1, the control device 18 comprises a storage unit 20 and a calculation unit 22.

[0018] The storage unit 20 includes one or more memories. The storage unit 20 includes non-volatile memory such as ROM (Read Only Memory), flash memory, or magnetic disk. Non-volatile memory is a storage medium that stores programs, tables, maps, etc., on a non-temporary basis. At least a portion of the storage unit 20 may be implemented by a storage medium such as USB (Universal Serial Bus) memory, memory card, or optical disk. The storage unit 20 may also include volatile memory such as RAM (Random Access Memory).

[0019] The arithmetic unit 22 includes a processing circuit capable of performing arithmetic processing. This processing circuit may have one or more processors. For example, the processing circuit may have a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc. The processing circuit may have an IC (Integrated Circuit) or discrete devices.

[0020] The arithmetic unit 22 includes a request output acquisition unit 24, an output control unit 26, a condition determination unit 28, a request output determination unit 30, and a performance acquisition unit 32. The request output acquisition unit 24, the output control unit 26, the condition determination unit 28, the request output determination unit 30, and the performance acquisition unit 32 are realized by the processing circuit described above. For example, the request output acquisition unit 24, the output control unit 26, the condition determination unit 28, the request output determination unit 30, and the performance acquisition unit 32 are realized by a program stored in the storage unit 20 being executed by the processor of the arithmetic unit 22. At least one of the above-mentioned IC and discrete device may realize at least a part of the request output acquisition unit 24, the output control unit 26, the condition determination unit 28, the request output determination unit 30, and the performance acquisition unit 32.

[0021] The request output acquisition unit 24 sequentially acquires the request output RP for the entire fuel cell system 12. More specifically, the request output acquisition unit 24 sequentially acquires request output information, which is information indicating the request output RP. The request output acquisition unit 24 acquires the request output information based on signals output from various sensors provided in the vehicle 10, for example. These various sensors include, but are not limited to, a position sensor provided in the vehicle 10 that detects the amount of operation (depression amount) of the accelerator pedal.

[0022] The output control unit 26 controls the output of multiple fuel cell units 14, including the first fuel cell unit 141 and the second fuel cell unit 142, so that the requested output RP is satisfied. The output control unit 26 can adjust the output of the multiple fuel cell units 14 by controlling multiple converter units 16 based on the requested output information acquired by the requested output acquisition unit 24.

[0023] The output control unit 26 includes an equal distribution control unit 261. The equal distribution control unit 261 performs equal distribution control. In equal distribution control, the output distribution of the multiple fuel cell units 14 is set equally based on the requested output RP indicated by the requested output information. In this case, the output control unit 26 adjusts the output of the multiple fuel cell units 14 by controlling, for example, the multiple converter units 16. The output distribution is the proportion of the output of the fuel cell system 12 that each of the multiple fuel cell units 14 occupies.

[0024] The output control unit 26 further comprises a performance acquisition preparation control unit 262 and an output maintenance control unit 263. A more detailed explanation of the performance acquisition preparation control unit 262 and the output maintenance control unit 263 will be given later.

[0025] The condition determination unit 28 determines whether or not a predetermined condition has been met. The condition determination unit 28 may determine that a predetermined condition has been met if a predetermined time has elapsed since the last time performance information was acquired by the performance acquisition unit 32. Alternatively, the condition determination unit 28 may determine that a predetermined condition has been met if the number of times the fuel cell system 12 has been started since the last time performance information was acquired by the performance acquisition unit 32 has reached a predetermined number of times. A more detailed explanation of the performance acquisition unit 32 and performance information will be given later. The predetermined time and predetermined number of times may be determined appropriately based on the results of experiments, simulations, etc., conducted in advance, or may be specified appropriately by the user of the fuel cell system 12 (vehicle 10).

[0026] The request output determination unit 30 performs a request output determination. In the request output determination, the request output RP indicated by the request output information and the predetermined output Pth are sequentially compared to determine whether the request output RP has reached the predetermined output Pth. If the condition determination unit 28 determines that the predetermined conditions have been met, the request output determination unit 30 performs a request output determination.

[0027] The predetermined output Pth is a threshold value relating to the required output RP for the entire fuel cell system 12. For example, the predetermined output Pth is predetermined to be greater than or equal to the sum of the rated output of the first fuel cell unit 141 and the output generated by the second fuel cell unit 142 in an idle state. It is preferable, but not limited to, that the predetermined output Pth is equal to this sum. The output of the second fuel cell unit 142 in an idle state is less than the rated output of the second fuel cell unit 142 and greater than zero. The magnitude of the output of the second fuel cell unit 142 in an idle state may be a lower limit value greater than zero within a range adjustable by the second converter unit 162.

[0028] The performance acquisition preparation control unit 262 (output control unit 26) described above performs performance acquisition preparation control until the requested output determination unit 30 determines that the requested output RP has reached a predetermined output Pth. Performance acquisition preparation control is a control that causes the second fuel cell unit 142 to generate power in an idle state to output a portion (a certain amount) of the requested output RP, while outputting the remaining portion of the requested output RP, excluding that portion, to the first fuel cell unit 141. In other words, performance acquisition preparation control is a control that maintains the output distribution of each of the multiple fuel cell units 14 at a level greater than zero, while setting the output distribution of the first fuel cell unit 141 to be greater than the output distribution of the other fuel cell units 14. If the requested output RP increases during the period in which performance acquisition preparation control is being performed, the performance acquisition preparation control unit 262 takes action by increasing the output distribution of the first fuel cell unit 141. Performance acquisition preparation control unit 262 realizes performance acquisition preparation control by controlling multiple converter units 16.

[0029] The performance acquisition unit 32 executes a performance acquisition process. The performance acquisition process is a process for acquiring performance information indicating the performance of the first fuel cell unit 141. The performance acquisition unit 32 acquires performance information by evaluating the IV characteristics of the first fuel cell unit 141 based on detection signals from voltage sensors, current sensors, etc., appropriately arranged in the fuel cell system 12 (first converter unit 161). The performance acquisition unit 32 executes the performance acquisition process when the requested output determination unit 30 determines that the requested output RP has reached a predetermined output Pth. It is preferable, but not limited to, that the performance acquisition unit 32 executes the performance acquisition process immediately after the requested output determination unit 30 determines that the requested output RP has reached a predetermined output Pth.

[0030] From the time the requested output determination unit 30 determines that the requested output RP has reached a predetermined output Pth until the performance information is acquired by the performance acquisition unit 32, the output maintenance control unit 263 (output control unit 26) described above performs output maintenance control. Output maintenance control is a control to maintain the output of the first fuel cell unit 141 at the time the requested output determination unit 30 determines that the requested output RP has reached a predetermined output Pth. If the requested output RP increases during the period in which output maintenance control is being performed, the output maintenance control unit 263 takes action by increasing the output distribution of the second fuel cell unit 142. The output maintenance control unit 263 achieves output maintenance control by controlling a plurality of converter units 16.

[0031] Furthermore, if performance information is acquired by the performance acquisition unit 32, the equal distribution control by the equal distribution control unit 261 described above is executed (restarted). For example, at the time the performance information is acquired by the performance acquisition unit 32, the output distribution of the first fuel cell unit 141 may be greater than the output distribution of the second fuel cell unit 142. In this case, the equal distribution control unit 261 gradually lowers the output distribution of the first fuel cell unit 141 while gradually increasing the output distribution of the second fuel cell unit 142 so that the requested output RP is satisfied.

[0032] Figure 2 is a flowchart of a control method according to one embodiment. Figure 3A is a graph illustrating the time progression of the output of the first fuel cell unit 141 when the control method of Figure 2 is executed. Figure 3B is a graph illustrating the time progression of the output of the second fuel cell unit 142 when the control method of Figure 2 is executed. Figure 3C is a graph illustrating the time progression of the requested output RP when the control method of Figure 2 is executed.

[0033] The control device 18, which is a computer, can execute the control method shown in Figure 2. As shown in Figure 2, the control method includes a condition determination step S1, a request output acquisition step S2, a request output determination step S3, a performance acquisition preparation control step S4, a performance acquisition step S5, and an equal distribution control step S6.

[0034] In the condition determination step S1, the condition determination unit 28 determines whether or not a predetermined condition has been met. If the predetermined condition has not been met, the equal distribution control step S6 is executed after the request output acquisition step S2 (described later) (S1: NO), and this control method ends. On the other hand, if the predetermined condition has been met, the request output determination step S3 is executed after the request output acquisition step S2 (S1: YES).

[0035] In the request output acquisition step S2, the request output acquisition unit 24 acquires request output information. In the request output determination step S3, the request output determination unit 30 performs a request output determination based on the request output information.

[0036] If the request output determination determines that the request output RP has reached a predetermined output Pth (RP ≥ Pth), the performance acquisition step S5 is executed. On the other hand, if the request output determination determines that the request output RP has not reached the predetermined output Pth (RP < Pth), the performance acquisition preparation control step S4 is executed, followed by the request output acquisition step S2 and the request output determination step S3 being executed again. Therefore, the request output acquisition step S2 to the performance acquisition preparation control step S4 are repeatedly executed until the request output RP reaches the predetermined output Pth.

[0037] In the performance acquisition preparation control step S4, the output control unit 26 (performance acquisition preparation control unit 262) performs performance acquisition preparation control. As a result, a certain amount of the requested output RP is output by the idle second fuel cell unit 142. In addition, the remaining portion of the requested output RP that is not output by the second fuel cell unit 142 is output by the first fuel cell unit 141. In this case, until the requested output RP reaches a predetermined output Pth, the output of the first fuel cell unit 141 increases in accordance with the increase in the requested output RP, but the output of the second fuel cell unit 142 is suppressed to be approximately constant (see also time points t0 to t1 in Figures 3A to 3C).

[0038] In the performance acquisition step S5, the performance acquisition unit 32 acquires performance information of the first fuel cell unit 141. Preferably, the performance acquisition unit 32 acquires the performance information when the requested output RP reaches a predetermined output Pth (time t1 in Figures 3A to 3C), but it may also acquire the performance information after time t1. For example, the performance information may be acquired at time t2, which is after time t1 shown in Figures 3A to 3C.

[0039] If the performance acquisition step S5 is started after time t1, it is preferable that the output maintenance control step S5A is executed from time t1 until time t2 when the performance acquisition step S5 is completed. In the output maintenance control step S5A, the output control unit 26 (output maintenance control unit 263) executes output maintenance control. In this case, until performance information is acquired, the output of the second fuel cell unit 142 increases in accordance with the increase in the requested output RP, but the output of the first fuel cell unit 141 is maintained at approximately a constant level (see also time t1 to time t2 in Figures 3A to 3C).

[0040] The equal distribution control step S6 is performed after the completion of the performance acquisition step S5. As described above, the equal distribution control step S6 is also performed if the predetermined conditions are not met. In the equal distribution control step S6, the output control unit 26 (equal distribution control unit 261) performs equal distribution control. As a result, for example, as shown in Figures 3A to 3C, the output of the first fuel cell unit 141 decreases from time t2 onwards. On the other hand, the output of the second fuel cell unit 142 increases from time t2 onwards in Figures 3A to 3C. Although not illustrated in Figures 3A to 3C, the equal distribution control equalizes the output distribution of the first fuel cell unit 141 and the output distribution of the second fuel cell unit 142.

[0041] The control device 18, fuel cell system 12, and control method described above will produce the effects and benefits described below, for example.

[0042] According to the present embodiment, the control device 18 (performance acquisition unit 32) acquires the performance information of the first fuel cell unit 141 after the required output RP reaches the predetermined output Pth. The control device 18 (output control unit 26) executes performance acquisition preparation control until the required output RP reaches the predetermined output Pth. Thereby, the control device 18 can sufficiently increase the output of the first fuel cell unit 141 before acquiring the performance information. Therefore, the control device 18 (performance acquisition unit 32) can acquire the performance information well.

[0043] When the required output RP reaches the predetermined output Pth, the control device 18 can acquire the performance information of the first fuel cell unit 141. In that case, the control device 18 contributes to promptly advancing, for example, the process of performance evaluation of the first fuel cell unit 141 based on the performance information.

[0044] The control device 18 may execute output maintenance control from when the required output RP reaches the predetermined output Pth until the performance information is acquired. Thereby, the control device 18 can suppress the output of the first fuel cell unit 141 from decreasing before the performance information is acquired. That is, the control device 18 can maintain a situation where good performance information can be acquired until the performance information is acquired.

[0045] The predetermined output Pth is preferably not less than the sum of the rated output of the first fuel cell unit 141 and the output due to power generation in the idle state of the second fuel cell unit 142. Thereby, the output of the first fuel cell unit 141 at the stage when the required output RP reaches the predetermined output Pth during the performance acquisition preparation control reaches the rated output or more. Therefore, the control device 18 can acquire the performance information of the first fuel cell unit 141 in a state where the output of the first fuel cell unit 141 is at least the rated output or more.

[0046] The predetermined output Pth may be equal to the above-mentioned sum value. The frequency at which the required output RP reaches the above-mentioned sum value should be higher than the frequency at which the required output RP reaches the excess value of the sum value. By setting the predetermined output Pth equal to the above-mentioned sum value, the acquisition frequency of good performance information can be sufficiently ensured.

[0047] After acquiring the performance information, the control device 18 may execute equal distribution control. As a result, the output load of the first fuel cell unit 141 after the performance information is acquired is alleviated.

[0048] By the equal distribution control, the output of the first fuel cell unit 141 gradually decreases, and the output of the second fuel cell unit 142 gradually increases. The control device 18 can equalize the output loads of the plurality of fuel cell units 14 while satisfying the required output RP by causing the output decrease of the first fuel cell unit 141 and the output increase of the second fuel cell unit 142 to occur in parallel.

[0049] When a predetermined condition is satisfied, the control device 18 may execute performance acquisition preparation control. The control device 18 (condition determination unit 28) may determine that the predetermined condition is satisfied when (1) a predetermined time has elapsed since the performance information was last acquired, or (2) the number of startups of the fuel cell system 12 has reached a predetermined number since the performance information was last acquired. Since the performance acquisition preparation control is not executed until the predetermined condition is satisfied, an increase in the frequency of concentration of the output load on the first fuel cell unit 141 is suppressed.

[0050] Regarding the above-described embodiments and modified examples, the following additional notes are further disclosed.

[0051] (Note 1) The control device (18) according to the present disclosure is a control device for a fuel cell system (12) including a first fuel cell unit (141) and a second fuel cell unit (142), and comprises: a request output acquisition unit (24) that acquires a request output (RP) to the entire fuel cell system; an output control unit (26) that controls the output of the first fuel cell unit and the second fuel cell unit so that the request output is satisfied; and a performance acquisition unit (32) that acquires performance information indicating the performance of the first fuel cell unit, wherein until the request output reaches a predetermined output (Pth), the output control unit can perform performance acquisition preparation control, which causes the second fuel cell unit to generate power in an idle state to output a part of the request output, while the remaining part of the request output is output to the first fuel cell unit, and when the request output reaches the predetermined output during the execution of the performance acquisition preparation control, the performance acquisition unit acquires the performance information. As a result, the control device can acquire performance information well.

[0052] (Note 2) The control device described in Note 1 may be a control device in which the output control unit performs output maintenance control to maintain the output of the first fuel cell unit at the time the requested output reaches the predetermined output, until at least the performance information is acquired. This allows the control device to maintain a condition in which good performance information can be acquired until the performance information is acquired.

[0053] (Note 3) The control device described in Note 1 or 2 may be a control device in which the predetermined output is equal to or greater than the sum of the rated output of the first fuel cell unit and the output of the second fuel cell unit generated in the idle state. This allows the control device to acquire performance information of the first fuel cell unit when the output of the first fuel cell unit is at least equal to or greater than the rated output.

[0054] (Note 4) The control device described in Note 3 may also be a control device in which the predetermined output is equal to the sum of the values. This ensures that a sufficient frequency of acquiring good performance information can be secured.

[0055] (Note 5) The control device described in any one of Notes 1 to 4 may be a control device in which, when the performance information is acquired, the output control unit performs equal distribution control to set the output distribution between the first fuel cell unit and the second fuel cell unit to be equal. This reduces the output load on the first fuel cell unit after the performance information has been acquired.

[0056] (Note 6) The control device described in Note 5 may be a control device in which the equal distribution control includes a process of gradually lowering the output of the first fuel cell unit while gradually increasing the output of the second fuel cell unit so that the requested output is satisfied. In this way, the control device can equalize the output load of the multiple fuel cell units while satisfying the requested output.

[0057] (Note 7) The control device described in any one of Notes 1 to 6 may be a control device in which the output control unit executes the performance acquisition preparation control when a predetermined condition is met. This suppresses an increase in the frequency of the output load being concentrated in the first fuel cell unit.

[0058] (Note 8) The control device described in Note 7 may further include a condition determination unit (28) that determines whether or not the predetermined conditions have been met, wherein the condition determination unit determines that the predetermined conditions have been met when a predetermined time has elapsed since the last acquisition of the performance information, or when the number of times the fuel cell system has been started since the last acquisition of the performance information has reached a predetermined number of times.

[0059] (Note 9) The fuel cell system (12) relating to this disclosure comprises a control device described in any one of Notes 1 to 8, the first fuel cell unit, and the second fuel cell unit.

[0060] (Note 10) The control method according to the present disclosure is a control method for a fuel cell system (12) including a first fuel cell unit (141) and a second fuel cell unit (142), comprising: a request output acquisition step (S2) for acquiring request output information indicating a request output (RP) which is an output required for the fuel cell system; a performance acquisition preparation control step (S4) for executing performance acquisition preparation control in which the second fuel cell unit is made to generate power in an idle state until the request output reaches a predetermined output (Pth), thereby outputting a portion of the request output, while the remaining portion of the request output is output to the first fuel cell unit; and a performance acquisition step (S5) for which the request output reaches the predetermined output during the execution of the performance acquisition preparation control, and performance information indicating the performance of the first fuel cell unit is acquired.

[0061] While this disclosure has been described in detail, it is not limited to the individual embodiments described above. These embodiments can be added, replaced, modified, partially deleted, etc., in any way that does not depart from the gist of this disclosure or from the spirit of this disclosure derived from the claims and their equivalents. These embodiments can also be implemented in combination. For example, the order of operations and processes in the embodiments described above are given as examples only and are not limited thereto. The same applies when numerical values ​​or mathematical formulas are used in the description of the embodiments described above.

[0062] 12...Fuel cell system 14...Fuel cell unit 18...Control device 24...Requested output acquisition unit 26...Output control unit 28...Condition determination unit 32...Performance acquisition unit 141...First fuel cell unit 142...Second fuel cell unit Pth...Predetermined output RP...Requested output

Claims

1. A control device (18) for a fuel cell system (12) including a first fuel cell unit (141) and a second fuel cell unit (142), comprising: a request output acquisition unit (24) for acquiring a request output (RP) to the entire fuel cell system; an output control unit (26) for controlling the output of the first fuel cell unit and the second fuel cell unit so that the request output is satisfied; and a performance acquisition unit (32) for acquiring performance information indicating the performance of the first fuel cell unit, wherein, until the request output reaches a predetermined output (Pth), the output control unit can perform performance acquisition preparation control to cause the second fuel cell unit to generate electricity in an idle state to output a portion of the request output, while causing the first fuel cell unit to output the remaining portion of the request output, excluding the portion mentioned above; and when the request output reaches the predetermined output during the execution of the performance acquisition preparation control, the performance acquisition unit acquires the performance information.

2. A control device according to claim 1, wherein the output control unit performs output maintenance control to maintain the output of the first fuel cell unit at the time the requested output reaches the predetermined output, from the time the requested output reaches the predetermined output until the performance information is acquired.

3. A control device according to claim 1 or 2, wherein the predetermined output is equal to or greater than the sum of the rated output of the first fuel cell unit and the output of the second fuel cell unit generated in the idle state.

4. A control device according to claim 3, wherein the predetermined output is equal to the sum of the values.

5. A control device according to claim 1 or 2, wherein, when the performance information is obtained, the output control unit performs equal distribution control to set the output distribution between the first fuel cell unit and the second fuel cell unit to be equal.

6. A control device according to claim 5, wherein the equal distribution control includes a process of gradually increasing the output of the second fuel cell unit while gradually decreasing the output of the first fuel cell unit so that the requested output is satisfied.

7. A control device according to claim 1 or 2, wherein the output control unit executes the performance acquisition preparation control when a predetermined condition is met.

8. A control device according to claim 7, further comprising a condition determination unit (28) for determining whether or not the predetermined conditions have been met, wherein the condition determination unit determines that the predetermined conditions have been met when a predetermined time has elapsed since the last acquisition of the performance information, or when the number of times the fuel cell system has been started since the last acquisition of the performance information has reached a predetermined number of times.

9. A fuel cell system comprising: a control device according to claim 1 or 2; the first fuel cell unit; and the second fuel cell unit.

10. A control method for a fuel cell system (12) including a first fuel cell unit (141) and a second fuel cell unit (142), comprising: a request output acquisition step (S2) for acquiring request output information indicating a request output (RP) which is an output required for the fuel cell system; a performance acquisition preparation control step (S4) for executing performance acquisition preparation control, in which the second fuel cell unit is made to generate electricity in an idle state until the request output reaches a predetermined output (Pth), thereby outputting a portion of the request output, while the remaining portion of the request output is output to the first fuel cell unit; and a performance acquisition step (S5) for which the request output reaches the predetermined output during the execution of the performance acquisition preparation control, and performance information indicating the performance of the first fuel cell unit is acquired.

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