Power generation planning method, power generation planning device, and power generation system

Abstract

A power generation planning method according to the present disclosure is for a fuel cell device including a plurality of fuel cell units, the power generation planning method comprising: a step for receiving a planned power generation output value of the fuel cell device; a first determination step for determining the number of fuel cell units that are to generate power and the number of fuel cell units that are not to generate power, among the plurality of fuel cell units, in order to satisfy the planned power generation output value; and a second determination step for determining the number of fuel cell units that are to generate power in order to satisfy a value obtained by adding the total standby power of the fuel cell units that are not to generate power to the planned power generation output value.

Description

Power generation planning method, power generation planning device, and power generation system

[0001] The present disclosure relates to a power generation planning method, a power generation planning device, and a power generation system.

[0002] Patent Document 1 discloses a grid-connected operation control method for a fuel cell power generation system in which the output of a fuel cell is converted to AC by an inverter, part of the power is consumed by auxiliary equipment within the power generation system, and the remainder is output from the transmission end to another power system, and the method is characterized in that the amount of power consumed by the auxiliary equipment is added as a pre-calculated value to the output plan value given to the control unit for controlling the inverter, and the power detection value detected between the output end of the inverter and the feeder point to the auxiliary equipment is fed back to the control unit, thereby performing constant power control to keep the inverter output constant.

[0003] Patent No. 3588855

[0004] An object of the present disclosure is to provide, as an example, a power generation planning method, a power generation planning device, and a power generation system that can determine a power generation plan for a fuel cell device including a plurality of fuel cell units more appropriately than in the past.

[0005] In order to solve the above problem, one aspect of the present disclosure is a power generation planning method for a fuel cell device including a plurality of fuel cell units, comprising: a step of receiving a power generation output plan value of the fuel cell device; a first determination step of determining the number of fuel cell units that will generate power and the number of fuel cell units that will not generate power among the plurality of fuel cell units in order to satisfy the power generation output plan value; and a second determination step of determining the number of fuel cell units that will generate power in order to satisfy a value obtained by adding the power generation output plan value to the total standby power of the fuel cell units that will not generate power.

[0006] Furthermore, one aspect of the present disclosure is a power generation planning method for a fuel cell device including a plurality of fuel cell units, comprising the steps of receiving a power generation output plan value for the fuel cell device, a first determination step of determining the output of each fuel cell unit of the fuel cell device so as to satisfy the power generation output plan value, and a second determination step of determining the output of each fuel cell unit of the fuel cell device so as to satisfy the power generation output plan value plus the total standby power of fuel cell units whose output has been determined to be 0.

[0007] Furthermore, one aspect of the present disclosure is a power generation planning device for a fuel cell device including a plurality of fuel cell units, comprising a communicator that receives a power generation output plan value of the fuel cell device, and a controller, wherein the controller makes a first decision to determine the number of fuel cell units that will generate power and the number of fuel cell units that will not generate power among the plurality of fuel cell units in order to satisfy the power generation output plan value received via the communicator, and also makes a second decision to determine the number of fuel cell units that will generate power in order to satisfy the power generation output plan value plus the total standby power of the fuel cell units that are not generating power.

[0008] Furthermore, one aspect of the present disclosure is a power generation planning device for a fuel cell device including a plurality of fuel cell units, comprising a communicator that receives a power generation output plan value of the fuel cell device, and a controller, wherein the controller makes a first decision to determine the output of each fuel cell unit of the fuel cell device so as to satisfy the power generation output plan value received via the communicator, and makes a second decision to determine the output of each fuel cell unit of the fuel cell device so as to satisfy the power generation output plan value plus the total standby power of fuel cell units that have been determined to have an output of 0.

[0009] A power generation system according to one aspect of the present disclosure includes a fuel cell device including a plurality of fuel cell units and the power generation planning device described above.

[0010] The power generation planning method, power generation planning device, and power generation system according to one aspect of the present disclosure provide an effect of being able to determine a power generation plan for a fuel cell device including a plurality of fuel cell units more appropriately than ever before.

[0011] FIG. 1 is a diagram illustrating that the net output of a fuel cell device differs between an AC output type fuel cell device and a DC output type fuel cell device even when the number of fuel cell units generating power and on standby within the fuel cell device is the same. FIG. 2 is a diagram illustrating that the net output of a fuel cell device differs between an AC output type fuel cell device and a DC output type fuel cell device even when the number of fuel cell units generating power and on standby within the fuel cell device is the same. FIG. 3 is a diagram illustrating an example of a power generation system including a power generation planning device of a first embodiment. FIG. 4 is a flowchart illustrating an example of the operation (power generation planning method) of the power generation planning device of the first embodiment. FIG. 5 is a flowchart illustrating an example of the operation (power generation planning method) of the power generation planning device of an example of the first embodiment. FIG. 6 is a flowchart illustrating an example of the operation (power generation planning method) of the power generation planning device of a second embodiment. FIG. 7 is a flowchart illustrating an example of the operation (power generation planning method) of the power generation planning device of an example of the second embodiment. FIG. 8 is a diagram illustrating an example of a power generation system including a power generation planning device of a third embodiment.

[0012] As mentioned above, Patent Document 1 considers a control method for covering the power consumption of the auxiliary equipment of a single fuel cell power generation device, but does not consider a control method that takes into account standby fuel cell power generation devices in a power generation system that includes multiple fuel cell power generation devices.

[0013] Generally, there are two types of power generation output methods for a single fuel cell unit: an AC output method in which an internal inverter is built into the fuel cell unit, and a DC output method in which an external inverter outside the fuel cell unit is used.

[0014] In such a fuel cell unit, in order to properly operate the auxiliary equipment within the fuel cell unit, a desired amount of power is required both during power generation and standby (non-power generation state). Here, the auxiliary equipment refers to peripheral equipment in the fuel cell unit, and includes, for example, electrical equipment such as control devices and sensors, and actuators such as valves and pumps.

[0015] Therefore, in an AC output fuel cell unit, the power consumed by the auxiliary equipment within the fuel cell unit is covered by the power it generates itself while it is generating electricity, and control is carried out taking into account the power consumed by these auxiliary equipment. This is because, in a configuration in which the power consumed by the auxiliary equipment is covered by power supplied from an external power source, separate equipment such as wiring to supply power from the external power source to the auxiliary equipment is required, which leads to poor installation and increased costs.

[0016] In contrast, in a DC output fuel cell unit, the power consumed by the auxiliaries within the fuel cell unit is supplied from the power supplied from an external power source during power generation, and control is performed without taking into account the power consumed by the auxiliaries. This is for the following reason: In a configuration in which the power consumed by the auxiliaries is supplied from the output of the fuel cell unit, as in the above-mentioned AC output fuel cell unit, a separate internal inverter for the auxiliaries is required to convert the DC output of the fuel cell unit into AC output. Furthermore, in a configuration in which the AC output converted via an external inverter is supplied to the auxiliaries, DC output adjustment is required to obtain AC output that takes into account the power consumed by the auxiliaries, making power control more complex than in a configuration in which power supplied from an external power source is supplied to the auxiliaries.

[0017] The power output of a fuel cell system including multiple fuel cell units is realized by combining fuel cell units that are generating power and fuel cell units that are on standby. In this case, operating each fuel cell unit at its rated output or on standby (pausing) is preferable from the perspective of optimizing the lifespan of each fuel cell unit in the fuel cell system, compared to operating all fuel cell units while adjusting their output.

[0018] Furthermore, even if the number of fuel cell units generating electricity and on standby within a fuel cell system is the same, the net output of the fuel cell system differs between an AC output fuel cell system and a DC output fuel cell system. For example, as shown in Figures 1 and 2, the net output T of a fuel cell system will differ when there are two fuel cell units generating electricity and one on standby within an AC output fuel cell system (Figure 1) and when there is a similar fuel cell unit within a DC output fuel cell system (Figure 2).

[0019] Therefore, a first aspect of the present disclosure is a power generation planning method for a fuel cell device including a plurality of fuel cell units, comprising: a step of receiving a power generation output plan value of the fuel cell device; a first determination step of determining the number of fuel cell units that will generate power and the number of fuel cell units that will not generate power among the plurality of fuel cell units in order to satisfy the power generation output plan value of the fuel cell device; and a second determination step of determining the number of fuel cell units that will generate power in order to satisfy a value obtained by adding the total standby power of the fuel cell units that are not generating power to the power generation output plan value of the fuel cell device.

[0020] According to the above, the power generation planning method of this aspect can determine a power generation plan for a fuel cell device including a plurality of fuel cell units more appropriately than ever before.

[0021] Specifically, the power generation planning method of this embodiment executes a second determination step to determine the number of fuel cell units that will generate power in order to satisfy the value obtained by adding the total standby power of the fuel cell units that are not generating power to the power generation output plan value of the fuel cell device, thereby reducing the possibility of not being able to properly plan the power generation of a fuel cell device that includes multiple fuel cell units compared to when the second determination step is not executed.

[0022] A second aspect of the power generation planning method of the present disclosure is a power generation planning method in which, in the first aspect, when the output of multiple fuel cell units is set to AC output, a second determination step is executed to determine the number of fuel cell units that will generate power in order to satisfy the value obtained by adding the total standby power of the fuel cell units that are not generating power to the power generation output plan value of the fuel cell device, and when the output of multiple fuel cell units is set to DC output, the second determination step does not have to be executed.

[0023] As described above, even if the number of fuel cell units generating electricity and on standby within a fuel cell system is the same, there is a possibility that the power generation of the fuel cell system cannot be properly planned because the net output of the fuel cell system differs between an AC output type fuel cell system and a DC output type fuel cell system. However, the power generation planning method of this aspect reduces the possibility of this happening compared to when the decision on whether to execute the second decision step is not made, by determining whether to execute the second decision step, which determines the number of fuel cell units generating electricity in order to satisfy the value obtained by adding the total standby power of the fuel cell units not generating electricity to the planned power generation output value of the fuel cell system, depending on the output type of the fuel cell units.

[0024] A third aspect of the power generation planning method of the present disclosure is a power generation planning method for a fuel cell device including a plurality of fuel cell units, and includes a step of receiving a planned power generation output value of the fuel cell device, a first determination step of determining the output of each fuel cell unit of the fuel cell device so as to satisfy the planned power generation output value of the fuel cell device, and a second determination step of determining the output of each fuel cell unit of the fuel cell device so as to satisfy the value obtained by adding the planned power generation output value of the fuel cell device to the total standby power of fuel cell units that have been determined to have an output of 0.

[0025] According to the above, the power generation planning method of this aspect can determine a power generation plan for a fuel cell device including a plurality of fuel cell units more appropriately than ever before.

[0026] Specifically, the power generation planning method of this embodiment executes a second determination step to determine the output of each fuel cell unit of the fuel cell device so as to satisfy the value obtained by adding the total standby power of fuel cell units whose output has been determined to be 0 to the power generation output plan value of the fuel cell device, thereby reducing the possibility that the power generation plan of a fuel cell device including multiple fuel cell units will not be properly planned compared to when this second determination step is not executed.

[0027] A fourth aspect of the power generation planning method of the present disclosure is a power generation planning method in which, in the third aspect, when the outputs of multiple fuel cell units are set to AC output, a second determination output step is executed to determine the output of each fuel cell unit of the fuel cell device so as to satisfy the value obtained by adding the total standby power of fuel cell units whose output has been determined to be 0 to the power generation output plan value of the fuel cell device, and when the outputs of multiple fuel cell units are set to DC output, the second determination step does not have to be executed.

[0028] As described above, even if the number of fuel cell units generating electricity and in standby within a fuel cell device is the same, there is a possibility that the power generation of the fuel cell device cannot be properly planned because the net output of the fuel cell device differs between an AC output type fuel cell device and a DC output type fuel cell device.However, the power generation planning method of this embodiment determines whether or not to execute a second decision step that determines the output of each fuel cell unit in the fuel cell device so as to satisfy the value obtained by adding the total standby power of fuel cell units that have been determined to have an output of 0 to the planned power generation output value of the fuel cell device, depending on the output type of the multiple fuel cell units, thereby reducing the above possibility compared to when the determination of whether or not to execute such second decision step is not made.

[0029] A fifth aspect of the present disclosure is a power generation planning device for a fuel cell device including a plurality of fuel cell units, comprising a communicator that receives a power generation output plan value of the fuel cell device, and a controller, wherein the controller makes a first decision to determine the number of fuel cell units that will generate power and the number of fuel cell units that will not generate power among the plurality of fuel cell units in order to satisfy the power generation output plan value of the fuel cell device received via the communicator, and also makes a second decision to determine the number of fuel cell units that will generate power in order to satisfy the value obtained by adding the total standby power of the fuel cell units that are not generating power to the power generation output plan value of the fuel cell device.

[0030] With this configuration, the power generation planning device of this aspect can determine a power generation plan for a fuel cell device including multiple fuel cell units more appropriately than in the past. Note that the details of the effects achieved by the power generation planning device of this aspect are the same as those achieved by the power generation planning method of the first aspect, and therefore will not be described here.

[0031] A sixth aspect of the present disclosure is a power generation planning device for a fuel cell device including a plurality of fuel cell units, comprising a communicator that receives a power generation output plan value of the fuel cell device, and a controller, wherein the controller makes a first decision to determine the output of each fuel cell unit of the fuel cell device so as to satisfy the power generation output plan value received via the communicator, and makes a second decision to determine the output of each fuel cell unit of the fuel cell device so as to satisfy the power generation output plan value plus the total standby power of fuel cell units that have been determined to have an output of 0.

[0032] With this configuration, the power generation planning device of this aspect can determine a power generation plan for a fuel cell device including multiple fuel cell units more appropriately than in the past. Note that the details of the effects achieved by the power generation planning device of this aspect are similar to the effects achieved by the power generation planning method of the third aspect, and therefore will not be described here.

[0033] A power generation system according to a seventh aspect of the present disclosure includes a fuel cell device including a plurality of fuel cell units, and the power generation planning device according to the fifth or sixth aspect.

[0034] With this configuration, the power generation system of this aspect can determine the power generation plan for the fuel cell device including multiple fuel cell units more appropriately than in the past. Note that the detailed effects of the power generation system of this aspect are similar to those of the power generation planning method of the first or third aspect, and therefore will not be described here.

[0035] Specific examples of the above-described aspects of the present disclosure will be described below with reference to the accompanying drawings. Each of the specific examples described below is an example of the above-described aspects of the present disclosure. Therefore, unless otherwise stated in the claims, the shapes, numerical values, components, arrangement positions and connection forms of the components shown below do not limit the scope of the claims.

[0036] Furthermore, among the components described below, components that are not described in the independent claims that represent the highest concept of the present disclosure are described as optional components. Furthermore, in the drawings, components with the same reference numerals may not be described in detail. The drawings are schematic illustrations of each component for ease of understanding, and the shapes, dimensional ratios, and the like may not be accurately depicted.

[0037] Furthermore, in the operation of the apparatus, the order of steps may be changed or known steps may be added as necessary.

[0038] First Embodiment [Device Configuration] FIG. 3 is a diagram showing an example of a power generation system including a power generation planning device according to a first embodiment.

[0039] As shown in FIG. 3, the power generation system 10 includes a fuel cell device 40, a control device 30, and a power generation planning device 20 for the fuel cell device 40.

[0040] Here, the fuel cell device 40 includes a plurality of fuel cell units, and the control device 30 controls the operation of the fuel cell device 40. Therefore, the power generation system 10 can be configured as a system that supplies large amounts of power to an electric power grid, for example. In this case, the power generation system 10 may include a fuel cell unit group including a plurality of fuel cell units, and the fuel cell device 40 may include a plurality of fuel cell devices formed by dividing the fuel cell unit group. The control device 30 may include a plurality of control devices, and each of the plurality of control devices may be provided corresponding to each of the plurality of fuel cell devices. A detailed configuration of the power generation system 10 as described above will be described in the third embodiment.

[0041] In the example shown in FIG. 3 , the power generation planning device 20 includes a communication device 21 and a controller 23 .

[0042] The communicator 21 is a receiver that receives the power generation output plan value of the fuel cell device 40. For example, the communicator 21 may receive the power generation output plan value transmitted from a terminal or a server via a communication network for each unit period.

[0043] The "unit period" may be, for example, about 30 minutes, but is not limited to this. The "unit period" can be set to an appropriate period based on the configuration of the power generation system 10, etc.

[0044] The users of the terminals or servers include direct or indirect users of the power generation planning device 20. A direct user of the power generation planning device 20 is, for example, an administrator of the power generation planning device 20. An indirect user of the power generation planning device 20 is, for example, the owner of the power generation system 10. Such an owner may be a consumer who receives the service of supplying power generated by the power generation system 10, or may be a power generation business operator who supplies power to consumers using the power generation system 10.

[0045] The controller 23 makes a first decision to determine the number of fuel cell units that will generate power and the number of fuel cell units that will not generate power among the multiple fuel cell units in order to satisfy the power generation output plan value of the fuel cell device 40 received via the communication device 21, and also makes a second decision to determine the number of fuel cell units that will generate power in order to satisfy the value obtained by adding the total standby power of the fuel cell units that are not generating power to the power generation output plan value of the fuel cell device 40.

[0046] The controller 23 may be any device having a control function, and includes an arithmetic processing unit (not shown) and a storage unit that stores a control program. The arithmetic processing unit reads and executes the control program stored in the storage unit, thereby performing predetermined control in the controller 23. An example of the arithmetic processing unit is a microprocessor. An example of the storage unit is a memory.

[0047] [Operation] Fig. 4 is a flowchart showing an example of the operation (power generation planning method) of the power generation planning device of the first embodiment. The following operation may be performed, for example, by the arithmetic processing unit of the controller 23 reading out a control program from the storage unit of the controller 23. However, it is not necessarily required that the following operation be performed by the controller 23. An operator may perform some of the operations. In the following example, a case where the operation is controlled by the controller 23 will be described.

[0048] First, when the operation of the power generation planning device 20 starts, in step S1, the power generation output plan value of the fuel cell device 40 including a plurality of fuel cell units is received via the communicator 21. For example, the power generation output plan value transmitted from a terminal or a server via a communication network may be received for each unit period.

[0049] Next, in step S2, the number of fuel cell units that will generate power and the number of fuel cell units that will not generate power are determined in order to satisfy the power generation output plan value of step S1. This provisionally (temporarily) determines the number of fuel cell units. Step S2 corresponds to the "first determination step" of this disclosure.

[0050] For example, if the power generation output plan value of step S1 is an integer multiple of the rated output of the fuel cell unit, the "number of fuel cell units generating power N1" in step S2 is calculated using the following formula (1), and the "number of fuel cell units not generating power N2" in step S2 is calculated using the following formula (2): N1 = power generation output plan value of step S1 / rated output of fuel cell unit (1) N2 = total number of fuel cell units - N1 (2)

[0051] If the planned power generation output value in step S1 is not an integer multiple of the rated output of the fuel cell unit, the "number N1 of fuel cell units generating power" and the "number N2 of fuel cell units not generating power" in step S2 may be calculated as follows.

[0052] First, when the output of a fuel cell unit can vary from 0 to the rated output, the sum (NA+1) of the number NA, which corresponds to the "quotient" when the power generation output plan value in step S1 is divided by the rated output of the fuel cell unit, and the number of fuel cell units (here, 1) operating at a desired output less than the rated output corresponds to the "number N1 of fuel cell units generating power" in step S2. Also, the "total number of fuel cell units - (NA+1)" corresponds to the "number N2 of fuel cell units not generating power" in step S2.

[0053] Next, if there is a lower limit value for the output of the fuel cell unit, the "number N1 of fuel cell units generating power" in step S2 is determined based on the relationship between the difference between the power generation output plan value in step S1 and an appropriate integer multiple of the rated output of the fuel cell unit and the lower limit value.

[0054] For example, if the rated output of the fuel cell unit is 5 kW and the lower limit is 2 kW, and the planned power generation output value in step S1 is 31 kW, it is not possible to realize a combination of six fuel cell units operating at the rated output (5 kW) and one fuel cell unit operating at 1 kW (31 kW = 5 kW x 6 + 1 kW x 1). Therefore, the "number of fuel cell units generating power N1" in step S2 must be realized by, for example, a combination of five fuel cell units operating at the rated output (5 kW) and two fuel cell units operating at 3 kW (31 kW = 5 kW x 5 + 3 kW x 2), or a combination of five fuel cell units operating at the rated output (5 kW), one fuel cell unit operating at 4 kW, and one fuel cell unit operating at 2 kW (31 kW = 5 kW x 5 + 4 kW x 1 + 2 kW x 1). In this case, however, the outputs of the two fuel cell units operated at less than the rated output may be any outputs other than those mentioned above, as long as they are 2 kW or more.

[0055] Next, in step S3, the number of fuel cell units that will generate power is determined so as to satisfy the power generation output plan value of step S1 plus the total standby power of the fuel cell units that are not generating power. This ultimately determines the number of fuel cell units. Step S3 corresponds to the "second determination step" of the present disclosure. Information indicating the "number of fuel cell units that will generate power" determined in step S3 is transmitted from the power generation planning device 20 to the control device 30 in a timely manner. Note that if the multiple fuel cell units that generate power include a fuel cell unit that does not have a rated output, information indicating the output of the fuel cell unit that does not have a rated output may also be transmitted from the power generation planning device 20 to the control device 30.

[0056] For example, the "total standby power W1 of fuel cell units not generating power" in step S3 is calculated using the following formula (3), and the "number N3 of fuel cell units generating power" in step S3 is calculated using the following formula (4) if the "power generation output plan value in step S1 + W1" is an integer multiple of the rated output of the fuel cell unit: W1 = N2 × (standby power of fuel cell unit) (3) N3 = (power generation output plan value in step S1 + W1) / rated output of fuel cell unit (4)

[0057] If the "power generation output plan value of step S1 + W1" is not an integer multiple of the rated output of the fuel cell unit, the method for calculating the "number of fuel cell units generating power N3" in step S3 can be easily understood from the method for calculating the "number of fuel cell units generating power N1" in step S2 above, so explanation will be omitted.

[0058] When the operation of the power generation planning device 20 is completed, the fuel cell device 40 starts generating power at an appropriate time.

[0059] According to the present embodiment described above, the power generation plan for the fuel cell device 40 including a plurality of fuel cell units can be determined more appropriately than ever before.

[0060] Specifically, according to this embodiment, by executing step S3, which determines the number of fuel cell units that will generate power in order to satisfy the value obtained by adding the total standby power of the fuel cell units that are not generating power to the planned power generation output value of the fuel cell device 40, the possibility of not being able to properly plan the power generation of the fuel cell device 40, which includes multiple fuel cell units, can be reduced compared to when step S3 is not executed.

[0061] (Example of First Embodiment) Fig. 5 is a flowchart showing an example of the operation of the power generation planning device (power generation planning method) of an example of the first embodiment. The following operation may be performed, for example, by the arithmetic processing unit of the controller 23 reading out a control program from the storage unit of the controller 23. However, it is not necessarily required that the following operation be performed by the controller 23. An operator may perform some of the operations. In the following example, a case where the operation is controlled by the controller 23 will be described.

[0062] Here, steps S1, S2 and S3 in FIG. 5 are similar to steps S1, S2 and S3 in FIG. 4, respectively, and therefore detailed description thereof will be omitted.

[0063] After the operation of step S2, in step S4, it is determined whether the outputs of the plurality of fuel cell units are set to AC output or DC output.

[0064] When the output of the plurality of fuel cell units is set to AC output (when "AC" is selected in step S4), the operation of step S3 is executed. In this case, the number of fuel cell units is finally determined by the operation of step S3.

[0065] On the other hand, when the outputs of the multiple fuel cell units are set to DC output ("DC" in step S4), the operation of step S3 is not executed. In this case, information indicating the "number of fuel cell units generating power" determined in step S2 is transmitted from the power generation planning device 20 to the control device 30 in a timely manner. Note that if the multiple fuel cell units generating power include a fuel cell unit that does not have a rated output, information indicating the output of the fuel cell unit that does not have a rated output may also be transmitted from the power generation planning device 20 to the control device 30.

[0066] When the operation of the power generation planning device 20 is completed, the fuel cell device 40 starts generating power at an appropriate time.

[0067] 1 and 2, even if the number of fuel cell units generating electricity and on standby within the fuel cell system 40 is the same, there is a possibility that the power generation of the fuel cell system 40 cannot be appropriately planned because the net output T of the fuel cell system 40 differs between an AC output type fuel cell system and a DC output type fuel cell system. However, according to this embodiment, by determining whether or not to execute step S3, which determines the number of fuel cell units generating electricity in order to satisfy the sum of the power generation output plan value of step S1 and the standby power of the fuel cell units not generating electricity, depending on the output type of the fuel cell units, this possibility can be reduced compared to when determining whether or not to execute step S3.

[0068] The power generation planning method, the power generation planning device 20, and the power generation system 10 of this embodiment may be the same as those of the first embodiment except for the above-mentioned features.

[0069] This embodiment is an example of a case where two cases can exist in a fuel cell device: one where the output of multiple fuel cell units is set to AC output, and one where the output of multiple fuel cell units is set to DC output.

[0070] On the other hand, in the fuel cell device, if the output of the multiple fuel cell units is set to AC output and the output of the multiple fuel cell units is not set to DC output, after step S2, step S4 is not executed, and step S3 is executed.

[0071] Second Embodiment A power generation planning method according to a second embodiment is similar to the power generation planning method according to the first embodiment, except for the control details of the controller 23, which will be described below.

[0072] 6 is a flowchart showing an example of the operation of the power generation planning device (power generation planning method) of the second embodiment. The following operations may be performed, for example, by the arithmetic processing unit of the controller 23 reading out a control program from the storage unit of the controller 23. However, it is not essential that the following operations be performed by the controller 23. An operator may perform some of the operations. In the following example, a case where the operations are controlled by the controller 23 will be described.

[0073] First, when the operation of the power generation planning device 20 starts, in step S11, the power generation output plan value of the fuel cell device 40 including a plurality of fuel cell units is received via the communicator 21. For example, the power generation output plan value transmitted from a terminal or a server via a communication network may be received for each unit period.

[0074] Next, in step S12, the output of each fuel cell unit of the fuel cell device 40 is determined so as to satisfy the power generation output plan value of step S11. This allows the output of each fuel cell unit to be provisionally (temporarily) determined. Step S12 corresponds to the "first determination step" of the present disclosure.

[0075] For example, when the power generation output plan value in step S11 is divided by the rated output of the fuel cell unit, if only a "quotient" exists, the output of the number of fuel cell units corresponding to the "quotient" is set to the rated output. The output of the other fuel cell units is set to 0.

[0076] If there is a "quotient" and a "remainder" when the power generation output plan value in step S11 is divided by the rated output of the fuel cell unit, the "output of each fuel cell unit" in step S12 may be calculated as follows.

[0077] First, when the output of a fuel cell unit can vary from 0 to the rated output, the output of the number of fuel cell units corresponding to the "quotient" is set to the rated output, and the output of one fuel cell unit is set to "the power generation output plan value of step S11 - the quotient value x the rated output of the fuel cell unit." The output of any other fuel cell unit is set to 0.

[0078] Next, if there is a lower limit value for the output of the fuel cell unit, the "output of each fuel cell unit" in step S12 is determined based on the magnitude relationship between the difference between the power generation output plan value in step S11 and an appropriate integer multiple of the rated output of the fuel cell unit and the lower limit value.

[0079] For example, if the rated output of a fuel cell unit is 5 kW and the lower limit is 2 kW, and the power generation output plan value in step S11 is 31 kW, a combination of a fuel cell unit operated at the rated output (5 kW) and a fuel cell unit operated at 1 kW (31 kW = 5 kW x 6 + 1 kW x 1) cannot be realized. Therefore, the "output of each fuel cell unit" in step S12 must be realized, for example, by a combination of a fuel cell unit operated at the rated output (5 kW) and a fuel cell unit operated at 3 kW (31 kW = 5 kW x 5 + 3 kW x 2), or by a combination of a fuel cell unit operated at the rated output (5 kW), a fuel cell unit operated at 4 kW, and a fuel cell unit operated at 2 kW (31 kW = 5 kW x 5 + 4 kW x 1 + 2 kW x 1). However, in this case, the outputs of the two fuel cell units operated below the rated output may be any other output as long as they are 2 kW or greater.

[0080] Next, in step S13, the output of each fuel cell unit in the fuel cell system 40 is determined so as to satisfy the power generation output plan value of step S11 plus the total standby power of the fuel cell units whose output has been determined to be 0. This determines the final output of each fuel cell unit. Step S13 corresponds to the "second determination step" of the present disclosure. Information indicating the "output of each fuel cell unit generating power" determined in step S13 is transmitted from the power generation planning device 20 to the control device 30 in a timely manner.

[0081] For example, when the power generation output plan value in step S11 plus the total standby power of fuel cell units whose output has been determined to be 0 is added together and divided by the rated output of the fuel cell units, if only a "quotient" exists, the output of the number of fuel cell units corresponding to the "quotient" is determined to be the rated output. The output of the other fuel cell units is determined to be 0.

[0082] When the sum of the power generation output plan value in step S11 and the total standby power of the fuel cell unit whose output has been set to 0 is divided by the rated output of the fuel cell unit, if there is a "quotient" and a "remainder", the method for calculating the "output of each fuel cell unit" in step S13 can be easily understood from the method for calculating the "output of each fuel cell unit" in step S12 above, so explanation will be omitted.

[0083] When the operation of the power generation planning device 20 is completed, the fuel cell device 40 starts generating power at an appropriate time.

[0084] According to the present embodiment described above, the power generation plan for the fuel cell device 40 including a plurality of fuel cell units can be determined more appropriately than ever before.

[0085] Specifically, according to this embodiment, by executing step S13 in which the output of each fuel cell unit of the fuel cell device 40 is determined so as to satisfy the value obtained by adding the total standby power of the fuel cell units whose output has been determined to be 0 to the planned power generation output value of the fuel cell device 40, the possibility of not being able to properly plan the power generation of the fuel cell device 40, which includes multiple fuel cell units, can be reduced compared to when step S13 is not executed.

[0086] The power generation planning method, power generation planning device 20, and power generation system 10 of this embodiment may be similar to those of the first embodiment or the examples of the first embodiment, except for the above-mentioned features.

[0087] (Example of Second Embodiment) Fig. 7 is a flowchart showing an example of the operation of the power generation planning device (power generation planning method) of an example of the second embodiment. The following operation may be performed, for example, by the arithmetic processing unit of the controller 23 reading out a control program from the storage unit of the controller 23. However, it is not necessarily required that the following operation be performed by the controller 23. An operator may perform some of the operations. In the following example, a case where the operation is controlled by the controller 23 will be described.

[0088] Here, steps S11, S12 and S13 in FIG. 7 are similar to steps S11, S12 and S13 in FIG. 6, respectively, and therefore detailed description thereof will be omitted.

[0089] After the operation of step S12, in step S14, it is determined whether the outputs of the plurality of fuel cell units are set to AC output or DC output.

[0090] When the outputs of the fuel cell units are set to AC output ("AC" in step S14), the operation of step S13 is executed. In this case, the output of each of the fuel cell units is finally determined by the operation of step S13.

[0091] On the other hand, when the outputs of the multiple fuel cell units are set to DC output ("DC" in step S14), the operation of step S13 is not executed. In this case, information indicating the "output of each fuel cell unit generating power" determined in step S12 is transmitted from the power generation planning device 20 to the control device 30 in a timely manner.

[0092] When the operation of the power generation planning device 20 is completed, the fuel cell device 40 starts generating power at an appropriate time.

[0093] 1 and 2, even if the number of fuel cell units generating power and on standby within the fuel cell system 40 is the same, there is a possibility that the power generation of the fuel cell system 40 cannot be appropriately planned because the net output of the fuel cell system 40 differs between an AC output type fuel cell system and a DC output type fuel cell system. However, according to this embodiment, by determining whether or not to execute step S13, which determines the output of each fuel cell unit in the fuel cell system 40 so as to satisfy the sum of the power generation output plan value of step S11 and the total standby power of fuel cell units that have been determined to have an output of 0, depending on the output type of the fuel cell units, this possibility can be reduced compared to when determining whether or not to execute step S13.

[0094] Other than the above-mentioned features, the power generation planning method, power generation planning device 20, and power generation system 10 of this embodiment may be the same as any of the first embodiment, the example of the first embodiment, and the second embodiment.

[0095] This embodiment is an example of a case where two cases can exist in a fuel cell device: one where the output of multiple fuel cell units is set to AC output, and one where the output of multiple fuel cell units is set to DC output.

[0096] On the other hand, in the fuel cell device, if the output of the multiple fuel cell units is set to AC output and the output of the multiple fuel cell units is not set to DC output, after step S2, step S4 is not executed, and step S3 is executed.

[0097] Third Embodiment FIG. 8 is a diagram showing an example of a power generation system including a power generation planning device according to a third embodiment.

[0098] As shown in Fig. 8, the power generation system 10 includes a power generation planning device 20 (see Fig. 3), control devices 30A to 30E, and fuel cell devices 40A to 40E. The internal configuration of the power generation planning device 20 is the same as that of the first embodiment, and therefore a detailed description thereof will be omitted.

[0099] Here, fuel cell devices 40A to 40E correspond to fuel cell device 40 in Figure 3. That is, in the example shown in Figure 8, power generation system 10 includes a fuel cell unit group consisting of a plurality of fuel cell units. The fuel cell unit group is divided according to appropriate rules, and a plurality of fuel cell units are grouped together. Although not shown, each of these fuel cell units is composed of a fuel cell stack, an AC-to-AC converter for converting DC power generated by the fuel cell stack into AC power and outputting it to the power grid, and a controller for controlling the operation of these devices.

[0100] In this example, the fuel cell unit groups are divided into fuel cell units a1-an belonging to fuel cell device 40A, fuel cell units b1-bn belonging to fuel cell device 40B, fuel cell units c1-cn belonging to fuel cell device 40C, fuel cell units d1-dn belonging to fuel cell device 40D, and fuel cell units e1-en belonging to fuel cell device 40E. All fuel cell units belonging to one fuel cell device are also simply referred to as "all fuel cell units of the fuel cell device."

[0101] However, the above configuration of the fuel cell unit group is merely an example and is not limited to this example. For example, the fuel cell unit group may be formed by grouping a plurality of fuel cell units into a single group.

[0102] Control devices 30A to 30E correspond to control device 30 in Fig. 3. That is, in the example shown in Fig. 8, control devices 30A to 30E are provided for fuel cell units a1 to an of fuel cell device 40A, fuel cell units b1 to bn of fuel cell device 40B, fuel cell units c1 to cn of fuel cell device 40C, fuel cell units d1 to dn of fuel cell device 40D, and fuel cell units e1 to en of fuel cell device 40E, respectively, and control the operation of all of the fuel cell units in the fuel cell devices.

[0103] For example, the control device 30A controls the output of each of the fuel cell units a1-an belonging to the fuel cell device 40A via a communication network so that these units can operate efficiently (for example, optimize their lifespans). Note that the fuel cell units may not be provided with control devices, and the operation of the fuel cell units belonging to each fuel cell device may be directly controlled by the control devices 30A-30E.

[0104] The control devices 30A to 30E may be any device that has a control function and includes a processing unit (not shown), a storage unit that stores a control program, and a communication device. The processing unit reads and executes the control program stored in the storage unit, thereby performing predetermined control in the control devices 30A to 30E. An example of the processing unit is a microprocessor. An example of the storage unit is a memory.

[0105] In this example, the power generation planning device 20 instructs each of the control devices 30A to 30E via a communication network with various information, such as a power generation plan including the power generation output plan values ​​of each of the fuel cell devices 40A to 40E, in response to, for example, the user's output requirements.

[0106] The above configuration of the power generation system 10 is an example, and is not limited to this example.

[0107] For example, the fuel cell units may not be provided with a control device, and the operation of the fuel cell units belonging to each group may be directly controlled by the control devices 30A to 30E.

[0108] Furthermore, the controller 23 (see FIG. 3) of the power generation planning device 20 makes a first decision to determine the number of fuel cell units that will generate power and the number of fuel cell units that will not generate power among the plurality of fuel cell units in order to satisfy the planned power generation output value of the fuel cell device 40, and also makes a second decision to determine the number of fuel cell units that will generate power in order to satisfy the total value obtained by adding the total standby power of the fuel cell units that are not generating power to the planned power generation output value of the fuel cell device 40, but is not limited to this. Such decisions may also be made by a control device other than the controller 23 (for example, control devices 30A to 30E).

[0109] Furthermore, the power generation planning device 20 may be integrated with the control devices 30A to 30E, in other words, equipped with the control functions of the control devices 30A to 30E, and may directly control the operation of each of all the fuel cell units in the fuel cell device 40.

[0110] The effects achieved by the power generation planning method, power generation planning device 20, and power generation system 10 of this embodiment are similar to those described in any of the first embodiment, the examples of the first embodiment, the second embodiment, and the examples of the second embodiment, so explanations will be omitted.

[0111] Other than the above-mentioned features, the power generation planning method, power generation planning device 20, and power generation system 10 of this embodiment may be similar to any of the first embodiment, the example of the first embodiment, the second embodiment, and the example of the second embodiment.

[0112] The first embodiment, the example of the first embodiment, the second embodiment, the example of the second embodiment, and the third embodiment may be combined with each other as long as they do not exclude each other. From the above description, many improvements and other embodiments of the present disclosure will be apparent to those skilled in the art. Therefore, the above description should be construed as merely illustrative and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present disclosure. Details of the structure and / or function thereof may be substantially changed without departing from the spirit of the present disclosure.

[0113] An aspect of the present disclosure can be used in a power generation planning method, a power generation planning device, and a power generation system that can determine a power generation plan for a fuel cell device including a plurality of fuel cell units more appropriately than before.

[0114] 10: Power generation system 20: Power generation planning device 21: Communication device 23: Controller 30A: Control device 30B: Control device 30C: Control device 30D: Control device 30E: Control device 40: Fuel cell device 40A: Fuel cell device 40B: Fuel cell device 40C: Fuel cell device 40D: Fuel cell device 40E: Fuel cell device a1 to an: Fuel cell unit b1 to bn: Fuel cell unit c1 to cn: Fuel cell unit d1 to dn: Fuel cell unit e1 to en: Fuel cell unit

Claims

1. A power generation planning method for a fuel cell device including a plurality of fuel cell units, comprising: a step of receiving a power generation output plan value of the fuel cell device; a first determination step of determining the number of fuel cell units that will generate power and the number of fuel cell units that will not generate power among the plurality of fuel cell units in order to satisfy the power generation output plan value; and a second determination step of determining the number of fuel cell units that will generate power in order to satisfy a value obtained by adding the power generation output plan value to the total standby power of the fuel cell units that are not generating power.

2. The power generation planning method of claim 1, wherein the second determination step is executed when the output of the plurality of fuel cell units is set to AC output, and the second determination step is not executed when the output of the plurality of fuel cell units is set to DC output.

3. A power generation planning method for a fuel cell device including a plurality of fuel cell units, comprising: a step of receiving a power generation output plan value of the fuel cell device; a first determination step of determining the output of each fuel cell unit of the fuel cell device so as to satisfy the power generation output plan value; and a second determination step of determining the output of each fuel cell unit of the fuel cell device so as to satisfy a value obtained by adding the power generation output plan value to the total standby power of fuel cell units whose output has been determined to be 0.

4. The power generation planning method of claim 3, wherein the second determination output step is executed when the output of the plurality of fuel cell units is set to AC output, and the second determination step is not executed when the output of the plurality of fuel cell units is set to DC output.

5. A power generation planning device for a fuel cell device including a plurality of fuel cell units, comprising: a communication device that receives a power generation output plan value of the fuel cell device; and a controller, wherein the controller makes a first decision to determine the number of fuel cell units that will generate power and the number of fuel cell units that will not generate power among the plurality of fuel cell units in order to satisfy the power generation output plan value received via the communication device, and makes a second decision to determine the number of fuel cell units that will generate power in order to satisfy a value obtained by adding the power generation output plan value to the total standby power of the fuel cell units that are not generating power.

6. A power generation planning device for a fuel cell device including a plurality of fuel cell units, comprising: a communication device that receives a power generation output plan value of the fuel cell device; and a controller, wherein the controller makes a first decision to determine the output of each fuel cell unit of the fuel cell device so as to satisfy the power generation output plan value received via the communication device, and makes a second decision to determine the output of each fuel cell unit of the fuel cell device so as to satisfy the power generation output plan value plus the total standby power of fuel cell units that have been determined to have an output of 0.

7. A power generation system comprising: a fuel cell device including a plurality of fuel cell units; and the power generation planning device according to claim 5 or 6.

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