Power control method, power control device, and power supply system

Abstract

A power control method according to the present disclosure comprises: a step in which, when power is supplied to a power load of a power consumer from a distributed power supply system provided with a fuel cell device and a power storage device, the power generated by the fuel cell device is controlled to a planned value for the power generated by the fuel cell device; and a step in which, while the aforementioned control is being executed, a first correction for reducing the planned value is executed when the charging rate of the power storage device after a prescribed time estimated on the basis of the planned value is greater than an upper limit value that is less than 100%, or a second correction for increasing the planned value is executed when the charging rate of the power storage device after the prescribed time estimated on the basis of the planned value is less than a lower limit value that is higher than 0%.

Description

Power control method, power control device, and power supply system

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

[0002] Various proposals have been made for power control of power supply systems. For example, Patent Document 1 describes determining the output of a fuel cell according to the amount of electricity stored in a storage battery. Specifically, it discloses control that reduces the output of the fuel cell when the amount of electricity stored in the storage battery is high, and increases the output of the fuel cell when the amount of electricity stored in the storage battery is low.

[0003] International Publication No. 2015 / 162940

[0004] An object of the present disclosure is to provide, as an example, a power control method, a power control device, and a power supply system that can reduce the possibility of a power storage device becoming fully charged or completely discharged compared to conventional methods.

[0005] In order to solve the above problem, a power control method according to one aspect of the present disclosure includes the steps of: when supplying power to a power load of a power consumer from a distributed power generation system including a fuel cell device and a power storage device, controlling the power generated by the fuel cell device to a planned value of the power generated by the fuel cell device; and, when the control is being performed, performing a first correction to decrease the planned value when the charging rate of the power storage device after a predetermined time estimated based on the planned value is greater than an upper limit value that is less than 100%, or performing a second correction to increase the planned value when the charging rate of the power storage device after a predetermined time estimated based on the planned value is less than a lower limit value that is greater than 0%.

[0006] One aspect of the present disclosure is a power control device for a distributed power system having a fuel cell device and a power storage device, comprising: a memory that stores a planned value of the power generation power of the fuel cell device; and a controller that controls the power generation power of the fuel cell device to the planned value of the power generation power of the fuel cell device when power is supplied from the distributed power system to a power load of a power consumer, and when the controller is performing the control, if the charging rate of the power storage device after a predetermined time estimated based on the planned value is greater than an upper limit value that is less than 100%, it performs a first correction that decreases the planned value, or if the charging rate of the power storage device after a predetermined time estimated based on the planned value is less than a lower limit value that is greater than 0%, it performs a second correction that increases the planned value.

[0007] A power supply system according to one aspect of the present disclosure includes a fuel cell device, a power storage device, and the above-described power control device.

[0008] The power control method, power control device, and power supply system according to one embodiment of the present disclosure have the effect of reducing the possibility that the power storage device will be fully charged or fully discharged compared to conventional cases.

[0009] FIG. 1 is a diagram illustrating an example of a power supply system according to a first embodiment. FIG. 2 is a diagram illustrating an example of a distributed power supply system provided in the power supply system according to the first embodiment. FIG. 3 is a diagram illustrating an example of a power control device according to the first embodiment. FIG. 4A is a flowchart illustrating an example of the operation (power control method) of the power control device according to the first embodiment. FIG. 4B is a flowchart illustrating an example of the operation (power control method) of the power control device according to the first embodiment. FIG. 5 is a diagram illustrating an example of the operation (power control method) of the power control device according to the first embodiment. FIG. 6 is a diagram illustrating an example of the operation of the power control device (power control method) in a first example of the first embodiment. FIG. 7 is a diagram illustrating an example of the operation of the power control device (power control method) in a second example of the first embodiment. FIG. 8 is a diagram illustrating an example of the operation of the power control device (power control method) in a third example of the first embodiment. FIG. 9 is a diagram illustrating an example of a distributed power supply system provided in a power supply system according to a fourth example of the first embodiment. FIG. 10 is a diagram illustrating an example of a power supply system according to a second embodiment. FIG. 11A is a flowchart illustrating an example of the operation (power control method) of the power control device according to the second embodiment. FIG. 11B is a flowchart showing an example of the operation (power control method) of the power control device of the second embodiment.

[0010] In Patent Document 1, a real-time measured value of the amount of electricity stored in the storage battery is used when determining the output of the fuel cell. Therefore, the invention described in Patent Document 1 does not describe a method for determining the output of the fuel cell that takes into account a future estimated value of the amount of electricity stored in the storage battery. As a result, the storage battery may be in a fully charged or completely discharged state. When the storage battery is in a fully charged state, reverse power flow from the distributed power source to the power grid is likely to occur. Conversely, when the storage battery is in a fully discharged state, power purchases from the power grid are likely to occur.

[0011] Therefore, the power control method of the first aspect of the present disclosure includes the steps of controlling the power generation power of the fuel cell device to a planned value of the power generation power of the fuel cell device when supplying power to a power load of a power consumer from a distributed power generation system including a fuel cell device and a power storage device, and performing a first correction to decrease the planned value when the charging rate of the power storage device after a predetermined time estimated based on the planned value of the power generation power of the fuel cell device is greater than an upper limit value less than 100% while performing the control, or performing a second correction to increase the planned value when the charging rate of the power storage device after a predetermined time estimated based on the planned value of the power generation power of the fuel cell device is less than a lower limit value greater than 0%.

[0012] According to the above, the power control method of this aspect can reduce the possibility that the power storage device will be in a fully charged state or a completely discharged state compared to conventional methods.

[0013] Specifically, when the power control method of this aspect is executing the control, if the charge rate of the power storage device after a predetermined time, which is estimated based on a planned value of the power generation power of the fuel cell device, is greater than an upper limit value which is smaller than 100%, a first correction is made to decrease the planned value, thereby appropriately reducing the possibility that the power storage device will be fully charged compared to when the first correction is not made. When the power storage device is fully charged, reverse power flow from the distributed power system to the power grid is likely to occur, but the power control method of this aspect can suppress such reverse power flow by the first correction.

[0014] Furthermore, when the power control method of this aspect is executing the control, if the charge rate of the power storage device after a predetermined time, estimated based on the planned value of the power generated by the fuel cell device, is lower than a lower limit value greater than 0%, a second correction is made to increase the planned value, thereby appropriately reducing the possibility of the power storage device becoming fully discharged compared to when the second correction is not made.When the power storage device becomes fully discharged, it becomes more likely to purchase power from the power grid, but the power control method of this aspect can suppress such power purchases by using the second correction.

[0015] A second aspect of the power control method of the present disclosure may be such that, in the power control method of the first aspect, the first predetermined period during which the first correction or the second correction is maintained is shorter than the second predetermined period during which the planned value of the power generation power of the fuel cell device is maintained.

[0016] The power control method of the third aspect of the present disclosure may be such that, in the power control method of the first or second aspect, the first or second correction described above does not need to be performed during the third predetermined period before the planned value of the power generation power of the fuel cell device is switched or during the fourth predetermined period after the planned value is switched.

[0017] When the first correction or the second correction is performed in a predetermined period before and after the timing when the planned value of the power generation of the fuel cell device is switched, the period during which the output of the fuel cell device changes based on the planned value of the power generation of the fuel cell device and the period during which the output of the fuel cell device changes based on the first correction or the second correction may overlap.

[0018] In other words, it takes a certain amount of time for the output of the fuel cell device to reach the desired target value, and if the first or second correction is performed immediately before the planned value of the power generation of the fuel cell device is changed, there is a possibility that an output change of the fuel cell device will be instructed based on the planned value of the power generation of the fuel cell device while the output of the fuel cell device is changing based on the first or second correction, which may make it difficult to control the output of the fuel cell device according to the planned power generation of the fuel cell device.

[0019] Furthermore, if the first or second correction is performed immediately after the planned value for the power generation of the fuel cell device is changed, there is a possibility that an output change of the fuel cell device will be instructed based on the first or second correction while the output of the fuel cell device is changing based on the planned value for the power generation of the fuel cell device, which may make it difficult to control the output of the fuel cell device in accordance with the correction of the power generation of the fuel cell device.

[0020] However, the power control method of this embodiment prohibits the execution of the first correction or the second correction during the third predetermined period before the planned value of the power generation power of the fuel cell device is switched or during the fourth predetermined period after the planned value is switched, making it easier to appropriately control the output of the fuel cell device compared to when the execution of the first correction and the second correction is not prohibited.

[0021] A fourth aspect of the power control method of the present disclosure is such that, in the power control method of the third aspect, the third specified period or the fourth specified period may be longer than the time required for the output of the fuel cell device to reach the switched planned value after the planned value of the power generation power of the fuel cell device is switched.

[0022] According to the above, the power control method of this embodiment sets the third specified period or the fourth specified period to be equal to or longer than the time required for the output of the fuel cell device to reach the switched planned value after switching the planned value of the power generation power of the fuel cell device, thereby appropriately reducing the possibility of overlap between the period in which the output of the fuel cell device changes based on the planned value of the power generation power of the fuel cell device and the period in which the output of the fuel cell device changes based on the first correction or the second correction, compared to when the third specified period and the fourth specified period are shorter than the required time.

[0023] A fifth aspect of the power control method of the present disclosure may be such that, in the power control method of the first aspect, the first correction or the second correction is not executed for a fifth predetermined period after starting execution of the first correction or the second correction.

[0024] It takes a certain amount of time for the output of the fuel cell device to reach the desired target value, and if the first or second correction is performed again immediately after the first or second correction, there is a possibility that the output of the fuel cell device will be instructed to change based on the latter correction while the output of the fuel cell device is still changing based on the former correction, which may make it difficult to control the output of the fuel cell device in accordance with the correction of the power generation power of the fuel cell device.

[0025] However, in the power control method of this embodiment, by prohibiting the re-execution of the first or second correction for a fifth predetermined period after starting the execution of the first or second correction, it becomes easier to appropriately control the output of the fuel cell device compared to when the re-execution of the first and second corrections is not prohibited.

[0026] A sixth aspect of the power control method of the present disclosure is the power control method of the first aspect, wherein the distributed power supply system further includes a solar power generation device, and when the above control is being performed, the charging rate of the power storage device after a predetermined time may be estimated from the difference between the actual value of the power demand of the power consumer in the immediately preceding sixth predetermined period and the sum of the actual value of the solar power generation device and the planned value of the power generation power of the fuel cell device.

[0027] According to the above, the power control method of this embodiment can appropriately estimate the charge rate of the power storage device after a predetermined time based on the difference between the most recent actual value of the power demand of the power consumer and the sum of the most recent actual value of the solar power generation device and the planned value of the power generation power of the fuel cell device, since this difference corresponds to the charging power or discharging power of the power storage device.

[0028] A seventh aspect of the present disclosure is a power control device for a distributed power system including a fuel cell device and a power storage device, comprising: a memory that stores a planned value of the power generation of the fuel cell device; and a controller that controls the power generation of the fuel cell device to the planned value of the power generation of the fuel cell device when power is supplied from the distributed power system to a power load of a power consumer, and when the controller is performing the above control, if the charging rate of the power storage device after a predetermined time estimated based on the planned value is greater than an upper limit value that is less than 100%, it performs a first correction that decreases the planned value, or if the charging rate of the power storage device after a predetermined time estimated based on the planned value is less than a lower limit value that is greater than 0%, it performs a second correction that increases the planned value.

[0029] With this configuration, the power control device of this aspect can reduce the possibility that the power storage device will be fully charged or fully discharged compared to conventional methods. Note that the details of the effects achieved by the power control device of this aspect are similar to the effects achieved by the power control method of the first aspect, and therefore will not be described here.

[0030] A power supply system according to an eighth aspect of the present disclosure includes a fuel cell device, a power storage device, and the power control device according to the seventh aspect.

[0031] With this configuration, the power supply system of this aspect can reduce the possibility that the power storage device will be fully charged or fully discharged compared to conventional methods. Note that the details of the effects achieved by the power supply system of this aspect are similar to the effects achieved by the power control method of the first aspect, and therefore will not be described here.

[0032] 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.

[0033] 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.

[0034] Furthermore, in the operation of the apparatus, the order of steps may be changed or known steps may be added as necessary.

[0035] (First embodiment) [Device configuration] Fig. 1 is a diagram illustrating an example of a power supply system according to a first embodiment. Fig. 2 is a diagram illustrating an example of a distributed power supply system provided in the power supply system according to the first embodiment. Fig. 3 is a diagram illustrating an example of a power control device according to the first embodiment.

[0036] As shown in Fig. 1, the power supply system 10 of this embodiment includes a power control device 20 and a distributed power supply system 30. Here, as shown in Fig. 2, the distributed power supply system 30 includes a fuel cell device 31 and a power storage device 32. This power supply system 10 may be, for example, a system that supplies large amounts of power to an electric power grid. In this case, the fuel cell device 31 and the power storage device 32 each include a fuel cell unit group consisting of a plurality of fuel cell units including a fuel cell stack, and a storage battery unit group consisting of a plurality of storage battery units, respectively. The detailed configuration of this power supply system 10 will be described in a second embodiment.

[0037] The fuel cell device 31 generates electricity using hydrogen supplied from a hydrogen supply source (not shown) under the control of the power control device 20. The power generated by the fuel cell device 31 is supplied to a power load 40, a power grid, or a power storage device 32. A well-known device can be used as the fuel cell device 31. An example of the hydrogen supply source is a hydrogen storage tank, but is not limited to this.

[0038] The power storage device 32 is a device that stores the power generated by the fuel cell device 31 or the power received from the power grid under the control of the power control device 20. The power stored in the power storage device 32 may be discharged to the power load 40 of the power consumer or to the power grid under the control of the power control device 20. Examples of power consumers that receive the power supply service generated by the power supply system 10 include, but are not limited to, factories, stores, and general households.

[0039] The power storage device 32 can transmit, at an appropriate timing, a state of charge (SOC) indicating the remaining amount of power (amount of charge) stored in the power storage device 32 to the power control device 20. The power storage device 32 can be, for example, a secondary battery, but is not limited to this.

[0040] As shown in FIG. 3 , the power control device 20 includes a storage unit 21 and a controller 22 .

[0041] The memory 21 stores the planned value FC of the power generation FC of the fuel cell device 31. ｍａｉｎFor example, the power control device 20 receives the planned value FC transmitted from a terminal or a server via a communication network. ｍａｉｎ The power generation plan for the power generation system may be received.

[0042] It should be noted that users of the terminal or server include direct or indirect users of the power control device 20. A direct user of the power control device 20 is, for example, an administrator of the power control device 20. An indirect user of the power control device 20 can be, for example, the owner of the power supply system 10. Such an owner may be a power consumer who receives the service of supplying power generated by the power supply system 10, or may be a power generation company that supplies power to power consumers using the power supply system 10.

[0043] When the distributed power supply system 30 supplies power to the power load 40 of the power consumer, the controller 22 sets the planned value FC of the power generation power FC of the fuel cell device 31 ｍａｉｎ During the execution of this control, the controller 22 controls the power generation FC of the fuel cell device 31 to a planned value FC ｍａｉｎ The state of charge SOC of the power storage device 32 after a predetermined time is estimated based on ｌａｔｏｒ Upper limit SOC is less than 100% ｕｐｐｅｒ When it is larger than the planned value FC ｍａｉｎ The first correction, or the planned value FC ｍａｉｎ The state of charge SOC of the power storage device 32 after a predetermined time is estimated based on ｌａｔｏｒ Lower limit SOC is greater than 0% ｌｏｗｅｒ When it is smaller than the planned value FC ｍａｉｎ A second correction is performed that increases

[0044] "Upper limit SOC ｕｐｐｅｒ " and "Lower limit SOC ｌｏｗｅｒ " can be set to an appropriate value based on the configuration of the power supply system 10, etc. ｕｐｐｅｒ ", for example, about 90%. "Lower limit SOC ｌｏｗｅｒ For example, about 10% can be mentioned.

[0045] The "predetermined time" can be set to an appropriate period based on the configuration of the power supply system 10. The "predetermined time" can be, for example, about 60 minutes.

[0046] Specific examples of the "first correction" and "second correction" will be described in the second embodiment.

[0047] The controller 22 may be any device having a control function, and includes an arithmetic processing unit (not shown) and a storage unit (not shown) 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 22. An example of the arithmetic processing unit is a microprocessor. An example of the storage unit is a memory.

[0048] [Operation] Figures 4A and 4B are flowcharts showing an example of the operation (power control method) of the power control device of the first embodiment. Figure 5 is a diagram for explaining an example of the operation (power control method) of the power control device of the first embodiment.

[0049] The following operations may be performed, for example, by the arithmetic processing unit of the controller 22 reading out a control program from the storage unit of the controller 22. However, it is not essential that the following operations be performed by the controller 22. An operator may perform some of the operations. In the following example, a case where the operations are controlled by the controller 22 will be described.

[0050] The operation of the power control device 20 in FIG. 4A will now be described.

[0051] First, the planned value FC of the power generation power FC of the fuel cell device 31 is transmitted via the communication network. ｍａｉｎ is received.

[0052] When the distributed power supply system 30 supplies power to the power load 40 of the power consumer, as shown in FIG. 4A, in step S1, the planned value FC of the power generation power FC of the fuel cell device 31 is calculated. ｍａｉｎ An operation for controlling the generated power FC of the fuel cell device 31 is performed.

[0053] Next, while the control of step S1 is being executed, in step S2A, the planned value FC of the power generation power FC of the fuel cell device 31 is calculated. ｍａｉｎ The state of charge SOC of the power storage device 32 after a predetermined time is estimated based on ｌａｔｏｒ However, the upper limit SOC is smaller than 100%. ｕｐｐｅｒ It is determined whether it is greater than

[0054] Here, the "predetermined time" may be, for example, about 60 minutes, but is not limited to this. ｕｐｐｅｒ " may be, for example, about 90%, but is not limited to this.

[0055] SOC of the power storage device 32 ｌａｔｏｒ Upper limit SOC is less than 100% ｕｐｐｅｒ If it is greater than the planned value FC of the power generation power FC of the fuel cell device 31 (if "Yes" in step S2A), then in step S3A, ｍａｉｎ Specifically, the correction value FC of the power generation power FC of the fuel cell device 31 is reduced. ｓｕｂ is calculated, and the planned value FC of the power generation power FC of the fuel cell device 31 is ｍａｉｎ That is, the planned value FC ｍａｉｎ Correction value FC ｓｕｂ The generated power FC of the fuel cell device 31 is obtained by adding these (FC = FC ｍａｉｎ +FC ｓｕｂ ). The above correction is an example of the "first correction" of the present disclosure.

[0056] For example, as shown in FIG. 5, the planned value FC of the power generation power FC of the fuel cell device 31 ｍａｉｎ At 300 kW, at time [0:20], the charging rate SOC of the storage device 32 ｌａｔｏｒ is the upper limit SOC ｕｐｐｅｒ When it is larger than (SOC ｌａｔｏｒ >SOC ｕｐｐｅｒ ), the correction value FC of the power generation FC of the fuel cell device 31 ｓｕｂ is calculated as -20 kW, the generated power FC of the fuel cell device 31 is corrected to 280 kW (FC = 300 kW - 20 kW). ｌａｔｏｒ But SOC ｕｐｐｅｒIt is calculated as the following value:

[0057] In addition, the planned value FC of the power generation FC of the fuel cell device 31 ｍａｉｎ At 300 kW, at time [0:25], the charging rate SOC of the storage device 32 ｌａｔｏｒ is the upper limit SOC ｕｐｐｅｒ When it is larger than (SOC ｌａｔｏｒ >SOC ｕｐｐｅｒ ), the correction value FC of the power generation FC of the fuel cell device 31 ｓｕｂ is calculated as -15 kW, the generated power FC of the fuel cell device 31 is corrected to 285 kW (FC = 300 kW - 15 kW). ｌａｔｏｒ But SOC ｕｐｐｅｒ It is calculated as the following value:

[0058] In addition, the planned value FC of the power generation FC of the fuel cell device 31 ｍａｉｎ When the power consumption is 350 kW, at time [1:00], the charging rate SOC of the storage device 32 is ｌａｔｏｒ is the upper limit SOC ｕｐｐｅｒ When it is larger than (SOC ｌａｔｏｒ >SOC ｕｐｐｅｒ ), the correction value FC of the power generation FC of the fuel cell device 31 ｓｕｂ is calculated as -5 kW, the generated power FC of the fuel cell device 31 is corrected to 345 kW (FC = 350 kW - 5 kW). ｌａｔｏｒ But SOC ｕｐｐｅｒ It is calculated as the following value:

[0059] SOC of the power storage device 32 ｌａｔｏｒ Upper limit SOC is less than 100% ｕｐｐｅｒ If the power generation capacity FC of the fuel cell device 31 is not larger than the planned value FC ｍａｉｎ will remain in its current state.

[0060] The operation of the power control device 20 in FIG. 4B will now be described.

[0061] First, the planned value FC of the power generation power FC of the fuel cell device 31 is transmitted via the communication network. ｍａｉｎ is received.

[0062] When the distributed power supply system 30 supplies power to the power load 40 of the power consumer, as shown in FIG. 4B, in step S1, the planned value FC of the power generation power FC of the fuel cell device 31 is set to ｍａｉｎ An operation for controlling the generated power FC of the fuel cell device 31 is performed.

[0063] Next, while the control of step S1 is being executed, in step S2B, the planned value FC of the power generation power FC of the fuel cell device 31 is calculated. ｍａｉｎ The state of charge SOC of the power storage device 32 after a predetermined time is estimated based on ｌａｔｏｒ is a lower limit SOC greater than 0% ｌｏｗｅｒ It is determined whether it is smaller than

[0064] Here, the "predetermined time" may be, for example, about 60 minutes, but is not limited to this. ｌｏｗｅｒ " may be, for example, about 10%, but is not limited to this.

[0065] SOC of the power storage device 32 ｌａｔｏｒ Lower limit SOC is greater than 0% ｌｏｗｅｒ If the power generation amount FC of the fuel cell device 31 is smaller than the planned value FC (YES in step S2B), the planned value FC ｍａｉｎ Specifically, the correction value FC of the power generation power FC of the fuel cell device 31 is increased. ｓｕｂ is calculated, and the planned value FC of the power generation power FC of the fuel cell device 31 is ｍａｉｎ That is, the planned value FC ｍａｉｎ Correction value FC ｓｕｂ The generated power FC of the fuel cell device 31 is obtained by adding these (FC = FC ｍａｉｎ +FC ｓｕｂ ). The above correction is an example of the "second correction" of the present disclosure.

[0066] For example, as shown in FIG. 5, the planned value FC of the power generation power FC of the fuel cell device 31 ｍａｉｎ At 300 kW, at time [0:45], the charging rate SOC of the storage device 32 ｌａｔｏｒ is the lower limit SOC ｌｏｗｅｒ When it is smaller than (SOC ｌａｔｏｒ <SOC ｌｏｗｅｒ), the correction value FC of the power generation FC of the fuel cell device 31 ｓｕｂ is calculated as +10 kW, the generated power FC of the fuel cell device 31 is corrected to 310 kW (FC=300 kW+10 kW). ｌａｔｏｒ But SOC ｌｏｗｅｒ It is calculated as a value that is equal to or greater than this.

[0067] In addition, the planned value FC of the power generation FC of the fuel cell device 31 ｍａｉｎ At 300 kW, at time [0:55], the charging rate SOC of the storage device 32 ｌａｔｏｒ is the lower limit SOC ｌｏｗｅｒ When it is smaller than (SOC ｌａｔｏｒ <SOC ｌｏｗｅｒ ), the correction value FC of the power generation FC of the fuel cell device 31 ｓｕｂ is calculated as +5 kW, the generated power FC of the fuel cell device 31 is corrected to 305 kW (FC = 300 kW + 5 kW). ｌａｔｏｒ But SOC ｌｏｗｅｒ It is calculated as a value that is equal to or greater than this.

[0068] SOC of the power storage device 32 ｌａｔｏｒ Lower limit SOC is greater than 0% ｌｏｗｅｒ If the power generation capacity FC of the fuel cell device 31 is not smaller than the planned value FC ｍａｉｎ will remain in its current state.

[0069] In addition, the "various times" and "planned value FC ｍａｉｎ " and "Correction value FC ｓｕｂ " are merely examples and are not limited to the present example. ｌａｔｏｒ " and "Correction value FC ｓｕｂ A specific example of a method for calculating " will be described in the second embodiment.

[0070] According to the present embodiment described above, the possibility that the power storage device 32 will be fully charged or fully discharged can be reduced compared to the prior art.

[0071] Specifically, the planned value FC of the power generation power FC of the fuel cell device 31 ｍａｉｎWhen the power generation FC of the fuel cell device 31 is controlled, the planned value FC of the power generation FC of the fuel cell device 31 is set to ｍａｉｎ The state of charge SOC of the power storage device after a predetermined time is estimated based on ｌａｔｏｒ However, the upper limit SOC is smaller than 100%. ｕｐｐｅｒ When it is larger than this, the planned value FC ｍａｉｎ By making a correction to decrease the current, it is possible to appropriately reduce the possibility that the power storage device 32 will be fully charged, compared to when such a correction is not made. When the power storage device 32 is fully charged, reverse power flow from the distributed power system 30 to the power grid is likely to occur, but according to this embodiment, the above correction can suppress the occurrence of such reverse power flow.

[0072] In addition, the planned value FC of the power generation FC of the fuel cell device 31 ｍａｉｎ When the power generation FC of the fuel cell device 31 is controlled, the planned value FC of the power generation FC of the fuel cell device 31 is set to ｍａｉｎ The state of charge SOC of the power storage device 32 after a predetermined time is estimated based on ｌａｔｏｒ Lower limit SOC is greater than 0% ｌｏｗｅｒ When it is smaller than this, the planned value FC ｍａｉｎ By making a correction to increase the current, it is possible to appropriately reduce the possibility that the power storage device 32 will enter a fully discharged state, compared to when such a correction is not made. When the power storage device 32 enters a fully discharged state, power purchases from the power grid are likely to occur, but according to this embodiment, the above correction can suppress such power purchases.

[0073] First Example The power control method of this example is the same as that of the first embodiment, except for the control details of the controller 22, which will be described below.

[0074] FIG. 6 is a diagram for explaining an example of the operation of the power control device (power control method) in the first example of the first embodiment.

[0075] As shown in FIG. 6, the planned value FC ｍａｉｎ or the planned value FC in step S3B of FIG. ｍａｉｎ The correction is maintained for a predetermined period T ｓｕｂis the planned value FC of the power generation FC of the fuel cell device 31 ｍａｉｎ is maintained for a predetermined period T ｍａｉｎ is shorter than.

[0076] Here, "predetermined period T ｓｕｂ " is an example of the "first predetermined period" in the present disclosure. ｍａｉｎ " is an example of the "second predetermined period" of the present disclosure, and is fixed to an appropriate length so as to suppress a decrease in the lifespan of the fuel cell device 31. ｍａｉｎ " may be, for example, about 60 minutes, but is not limited to this.

[0077] For example, in FIG. 6, the planned value FC of the generated power FC of the fuel cell device 31 is ｍａｉｎ is maintained at 300 kW for a predetermined period T ｍａｉｎ , the 60 minutes between time [0:00] and time [1:00] are shown.

[0078] 6 also shows the planned value FC of the power generation FC of the fuel cell device 31. ｍａｉｎ is maintained at 350 kW for a predetermined period T ｍａｉｎ , 60 minutes from time [1:00] to time [2:00] are shown.

[0079] FIG. 6 shows the planned value FC ｍａｉｎ Correction of (FC ｍａｉｎ -20kW) is maintained for a predetermined period T ｓｕｂ , the five minutes between time [0:20] and time [0:25] are shown.

[0080] Also, the planned value FC in step S3A of FIG. ｍａｉｎ Correction of (FC ｍａｉｎ -15kW) is maintained for a predetermined period T ｓｕｂ , the 20 minutes between time [0:25] and time [0:45] are shown.

[0081] In other words, the planned value FC ｍａｉｎ Correction of (FC ｍａｉｎ -20kW) is performed, and then a predetermined period T ｍａｉｎ During the 60-minute period, the planned value FC ｍａｉｎ Further correction of (FC ｍａｉｎ-15kW) is performed, the former correction (FC ｍａｉｎ -20kW) is reset.

[0082] 6 shows the planned value FC of step S3B of FIG. ｍａｉｎ Correction of (FC ｍａｉｎ +10 kW) is maintained for a predetermined period T ｓｕｂ , the 10 minutes between time [0:45] and time [0:55] are shown.

[0083] Also, the planned value FC in step S3B of FIG. ｍａｉｎ Correction of (FC ｍａｉｎ +5kW) is maintained for a predetermined period T ｓｕｂ , the five minutes between time [0:55] and time [1:00] are shown.

[0084] In other words, the planned value FC ｍａｉｎ Correction of (FC ｍａｉｎ +10 kW) is performed for a predetermined period T ｍａｉｎ During the 60-minute period, the planned value FC ｍａｉｎ Further correction of (FC ｍａｉｎ +5kW) is performed, the former correction (FC ｍａｉｎ +10kW) is reset.

[0085] Furthermore, FIG. 6 shows the planned value FC ｍａｉｎ Correction of (FC ｍａｉｎ -5kW) is maintained for a predetermined period T ｓｕｂ , the 60 minutes between time [1:00] and time [2:00] are shown.

[0086] That is, the planned value FC of the power generation FC of the fuel cell device 31 ｍａｉｎ The timing at which the correction (FC ｍａｉｎ -5kW) is performed at the same time, ｍａｉｎ -5 kW) is carried out.

[0087] Main correction (FC ｍａｉｎ -5kW) is performed, the planned value FC ｍａｉｎ Unless further correction of ｍａｉｎ (60 minutes), this correction (FCｍａｉｎ -5kW) is continued. ｍａｉｎ -5 kW) is the planned value FC of the power generation FC of the fuel cell device 31 ｍａｉｎ is reset when the switchover occurs.

[0088] In addition, the "various times," "various periods," and "planned values ​​FC ｍａｉｎ " and "Correction value FC ｓｕｂ " are merely examples and are not limited to these examples.

[0089] According to this embodiment, the planned value FC of the generated power FC of the fuel cell device 31 is ｍａｉｎ is maintained for a predetermined period T ｍａｉｎ is fixed to a relatively long predetermined period (for example, 60 minutes), which is advantageous for extending the life of the fuel cell device 31. In other words, the more the number of times the output of the fuel cell device 31 changes, the more likely the fuel cell is to deteriorate. Therefore, in this embodiment, the predetermined period T ｍａｉｎ By fixing the length of the junction to an appropriate length, the number of times the output of the fuel cell device 31 changes can be appropriately limited.

[0090] The planned value FC in step S3A of FIG. ｍａｉｎ or the planned value FC in step S3B of FIG. ｍａｉｎ The correction is maintained for a predetermined period T ｓｕｂ is the planned value FC of the power generation FC of the fuel cell device 31 ｍａｉｎ is maintained for a predetermined period T ｍａｉｎ Although it is shorter than the correction value FC of the power generation power FC of the fuel cell device 31, ｓｕｂ is the planned value FC of the power generation FC of the fuel cell device 31 ｍａｉｎ Since this is small compared to the change in the temperature, the effect on the life of the fuel cell device 31 is small.

[0091] As a result, according to this embodiment, the planned value FC of the generated power FC of the fuel cell device 31 is ｍａｉｎ is maintained for a predetermined period T ｍａｉｎ The life of the fuel cell device 31 can be extended compared to when the time is short and changes frequently.

[0092] The power control method, power control device 20, and power supply system 10 of this embodiment may be the same as those of the first embodiment except for the above-mentioned features.

[0093] Second Example The power control method of this example is the same as that of the first embodiment, except for the control details of the controller 22, which will be described below.

[0094] FIG. 7 is a diagram for explaining an example of the operation of the power control device (power control method) in the second example of the first embodiment.

[0095] As shown in FIG. 7, the planned value FC of the power generation FC of the fuel cell device 31 ｍａｉｎ In a predetermined period TA before the change of the planned value FC in step S3A of FIG. 4A or step S3B of FIG. 4B, ｍａｉｎ The "predetermined period TA" is an example of the "third predetermined period" of the present disclosure.

[0096] In addition, the planned value FC of the power generation FC of the fuel cell device 31 ｍａｉｎ In a predetermined period TB after the change of the planned value FC in step S3A of FIG. 4A or step S3B of FIG. 4B ｍａｉｎ The "predetermined period TB" is an example of the "fourth predetermined period" of the present disclosure.

[0097] In the example shown in FIG. 7, the time [0:55] is included in the "predetermined period TA", so the charging rate SOC of the power storage device 32 ｌａｔｏｒ is the lower limit SOC ｌｏｗｅｒ Even if the planned value FC in step S3B of FIG. ｍａｉｎ correction is not performed.

[0098] The planned value FC of the power generation FC of the fuel cell device 31 ｍａｉｎ At the timing when the switch occurs, as described above, the planned value FC ｍａｉｎ For example, as shown in FIG. 7, at time [1:00], the planned value FC ｍａｉｎ is switched from 300kW to 350kW, and correction (FC ｍａｉｎ -5 kW) is carried out.

[0099] Here, the "predetermined period TA" or the "predetermined period TB" is the planned value FC of the power generation of the fuel cell device 31. ｍａｉｎ After switching, the output of the fuel cell device 31 becomes the switched planned value FC ｍａｉｎ The "predetermined period TA" and the "predetermined period TB" may be, for example, equal to or longer than the time required for the output of the fuel cell device 31 to reach a desired target value upon startup of a standby fuel cell unit in the fuel cell device 31.

[0100] In addition, the "various times," "various periods," and "planned values ​​FC ｍａｉｎ " and "Correction value FC ｓｕｂ " are merely examples and are not limited to these examples.

[0101] Planned value FC of the power generated by the fuel cell device 31 ｍａｉｎ In a predetermined period before and after the timing when the planned value FC ｍａｉｎ When the correction is performed, the planned value FC of the power generation power FC of the fuel cell device 31 ｍａｉｎ There may be cases where the period during which the output of the fuel cell device 31 changes based on the above and the period during which the output of the fuel cell device 31 changes based on the above correction overlap.

[0102] That is, a certain time is required for the output of the fuel cell device 31 to reach the desired target value, and the planned value FC of the generated power FC of the fuel cell device 31 ｍａｉｎ When the correction is performed immediately before the change of the power generation capacity FC of the fuel cell device 31, the planned value FC ｍａｉｎ This may make it difficult to control the output of the fuel cell device 31 according to the planned power generation power FC of the fuel cell device 31.

[0103] In addition, the planned value FC of the power generation FC of the fuel cell device 31 ｍａｉｎ Immediately after the timing at which the planned value FC in step S3A of FIG. 4A or step S3B of FIG. 4B is switched, ｍａｉｎWhen the correction is performed, the planned value FC of the power generation power FC of the fuel cell device 31 ｍａｉｎ While the output of the fuel cell device is changing based on the correction, there is a possibility that an output change of the fuel cell device 31 will be instructed based on the correction. In this case, there is a possibility that the output of the fuel cell device 31 will not be controlled in accordance with the correction of the generated power FC of the fuel cell device 31.

[0104] However, according to this embodiment, the planned value FC of the generated power FC of the fuel cell device 31 ｍａｉｎ A predetermined period TA before the change or the planned value FC ｍａｉｎ In a predetermined period TB after the change, the planned value FC ｍａｉｎ By prohibiting the execution of the correction, it becomes easier to appropriately control the output of the fuel cell device 31 compared to when the execution of the correction is not prohibited.

[0105] According to this embodiment, the predetermined period TA or the predetermined period TB is set to the planned value FC of the power generation power FC of the fuel cell device 31. ｍａｉｎ After switching, the output of the fuel cell device 31 becomes the switched planned value FC ｍａｉｎ By setting the predetermined period TA and the predetermined period TB to be longer than the time required for the fuel cell device 31 to reach the planned value FC ｍａｉｎ The period in which the output of the fuel cell device 31 changes based on the planned value FC in step S3A of FIG. 4A or step S3B of FIG. ｍａｉｎ Therefore, it is possible to appropriately reduce the possibility that the period during which the output of the fuel cell device 31 changes based on the correction of the above-mentioned difference will overlap with the period during which the output of the fuel cell device 31 changes based on the correction of the above-mentioned difference.

[0106] Other than the above-mentioned features, the power control method, power control device 20, and power supply system 10 of this embodiment may be similar to those of the first embodiment or the first example of the first embodiment.

[0107] Third Embodiment The power control method of this embodiment is the same as that of the first embodiment, except for the control details of the controller 22, which will be described below.

[0108] FIG. 8 is a diagram for explaining an example of the operation of the power control device (power control method) in the third example of the first embodiment.

[0109] As shown in FIG. 8, the planned value FC ｍａｉｎ After the execution of the correction is started, the predetermined period TC is ｍａｉｎ The "predetermined period TC" is an example of the "fifth predetermined period" of the present disclosure.

[0110] In the example shown in FIG. 8, the time [0:25] is included in the "predetermined period TC", so the charging rate SOC of the power storage device 32 ｌａｔｏｒ is the upper limit SOC ｕｐｐｅｒ Even if the planned value FC in step S3A of FIG. ｍａｉｎ correction is not performed.

[0111] Here, the "predetermined period TC" may be, for example, a period of time or more until the output of the fuel cell device 31 reaches a desired target value due to activation of a standby fuel cell unit in the fuel cell device 31.

[0112] It should be noted that the "various times," "various periods," and "planned values ​​FC ｍａｉｎ " and "Correction value FC ｓｕｂ " are merely examples and are not limited to these examples.

[0113] A certain time is required for the output of the fuel cell device 31 to reach the desired target value. ｍａｉｎ If the correction is performed again immediately after the correction in (2), there is a possibility that a change in the output of the fuel cell device 31 will be instructed based on the latter correction while the output of the fuel cell device 31 is changing based on the former correction. This may make it difficult to control the output of the fuel cell device 31 in accordance with the correction of the power generation power FC of the fuel cell device 31.

[0114] However, according to this embodiment, the planned value FC in step S3A of FIG. 4A or step S3B of FIG. 4B ｍａｉｎAfter the execution of the correction is started, the correction is prohibited from being executed again for a predetermined period TC, and the planned value FC ｍａｉｎ In this case, it becomes easier to appropriately control the output of the fuel cell device 31 compared to when the re-execution of the correction is not prohibited.

[0115] Other than the above-mentioned features, the power control method, power control device 20, and power supply system 10 of this embodiment may be the same as those of the first embodiment and any of the first and second examples of the first embodiment.

[0116] Fourth Embodiment A power control method of this embodiment is similar to that of the first embodiment, except for the configuration of a distributed power system 130 and the control content of the controller 22, which will be described below.

[0117] FIG. 9 is a diagram illustrating an example of a distributed power supply system provided in a power supply system according to a fourth example of the first embodiment.

[0118] 9, the distributed power supply system 130 includes a fuel cell device 31, a power storage device 32, and a solar power generation device 33. Here, the configurations of the fuel cell device 31 and the power storage device 32 are the same as those in the first embodiment, and therefore a description thereof will be omitted.

[0119] The solar power generation device 33 is an electric power device that uses sunlight to convert light energy into electric power under the control of the power control device 20. The electric power generated by the solar power generation device 33 is supplied to the electric power load 40, the electric power grid, or the electric storage device 32. A well-known device can be used as the solar power generation device 33.

[0120] The power supply system 10 may be, for example, a system that supplies a large amount of power to a power grid. In this case, the fuel cell device 31, the solar power generation device 33, and the power storage device 32 each include a fuel cell unit group consisting of a plurality of fuel cell units including a fuel cell stack, a solar cell group consisting of a plurality of solar cells including a solar panel, and a storage battery unit group consisting of a plurality of storage battery units, respectively. The detailed configuration of such a power supply system 10 will be described in a second embodiment.

[0121] In this embodiment, the planned value FC of the generated power FC of the fuel cell device 31 ｍａｉｎ When the power generation power FC of the fuel cell device 31 is controlled, the actual value of the power demand of the power consumer in the immediately preceding predetermined period TD, the actual value of the power generation power FC of the solar power generation device 33, and the planned value FC of the power generation power FC of the fuel cell device 31 are calculated. ｍａｉｎ The charging rate SOC of the power storage device 32 after a predetermined time from the difference between the sum of ｌａｔｏｒ The "predetermined period TD" is an example of a "sixth predetermined period" in the present disclosure. The "predetermined period TD" can be, for example, about 15 minutes, but is not limited to this.

[0122] Here, the power demand of the power consumers and the power generated by the solar power generation device 33 are measured at an appropriate sampling period by the controller 22, and the sampling data is stored as actual values ​​in the power database. Therefore, the controller 22 can acquire the actual values ​​of the power demand of the power consumers and the actual values ​​of the power generated by the solar power generation device 33 during the predetermined period TD from the power database.

[0123] According to this embodiment, the immediately preceding actual value of the power demand of the power consumer, the immediately preceding actual value of the solar power generation device 33, and the planned value FC of the power generation power FC of the fuel cell device 31 are calculated. ｍａｉｎ The difference between the sum of the charge rate SOC and the charge rate SOC of the power storage device 32 corresponds to the charge power or discharge power of the power storage device 32. ｌａｔｏｒ can be appropriately estimated.

[0124] Other than the above-mentioned features, the power control method, power control device 20 and power supply system 10 of this embodiment may be the same as those of the first embodiment and any of the first to third examples of the first embodiment.

[0125] Second Embodiment [Device Configuration] Fig. 10 is a diagram showing an example of a power supply system according to a second embodiment. In Fig. 10, for convenience, solid lines and dashed lines respectively indicate paths through which power is transmitted and paths through which signals are transmitted.

[0126] As shown in FIG. 10, the power supply system 10 of this embodiment includes a power control device 20, a fuel cell device 31, a power storage device 32, a solar power generation device 33, and control devices 50A to 50C.

[0127] Here, the internal configuration of the power control device 20 is the same as that of the first embodiment, and therefore a detailed description thereof will be omitted.

[0128] 10, the fuel cell device 31 includes a fuel cell unit group consisting of a plurality of fuel cell units. The fuel cell unit group is divided into a plurality of groups, and the fuel cell units in each group are connected to the power grid via a power conditioner (PCS) and a power meter. The power meter is connected to the power control device 20 via a communication network. The number of fuel cell units in each group is set to an appropriate value depending on the output specifications of the power supply system 10, etc.

[0129] Although not shown, each of these fuel cell units is composed of auxiliary equipment such as a fuel cell stack, pumps, and valves, as well as a control device that controls the operation of these devices. If a control device is not provided within the fuel cell unit, the operation of the above-mentioned devices may be directly controlled by the control device 50A.

[0130] The photovoltaic power generation device 33 includes a solar cell group consisting of a plurality of solar cells including a solar panel. The solar cell group is divided into a plurality of groups each of which is connected to the power grid via a power conditioner (PCS) and a power meter. The power meter is connected to the power control device 20 via a communication network. The number of solar cells in each group is set to an appropriate value depending on the output specifications of the power supply system 10, etc.

[0131] The power storage device 32 includes a storage battery unit group consisting of a plurality of storage battery units. The storage battery unit group is divided into a plurality of groups, and the storage battery units in each group are connected to the power grid by power lines via a power conditioner (PCS) and a power meter. The power meter is connected to the power control device 20 via a communication network. The number of storage battery units in each group is set to an appropriate value depending on the output specifications of the power supply system 10, etc.

[0132] Furthermore, the fuel cell device 31, the power storage device 32, and the solar power generation device 33 are connected in parallel to one another via a power grid, and are also connected to a power load 40 of a power consumer via a power meter. This power meter is connected to the power control device 20 via a communication network.

[0133] However, the above configuration of the power supply system 10 is merely an example and is not limited to this example. For example, the fuel cell unit group may be grouped by a single group of multiple fuel cell units, or by a single fuel cell unit within each group. The solar cell group may be grouped by a single group of multiple solar cells, or by a single solar cell within each group. The storage battery unit group may be grouped by a single group of multiple storage battery units, or by a single storage battery unit within each group.

[0134] The control devices 50A to 50C are provided corresponding to the fuel cell device 31, the power storage device 32, and the solar power generation device 33, respectively, and are connected to the power control device 20 via a communication network.

[0135] For example, the control device 50A controls the output of each of these fuel cell units via the communication network to enable efficient operation of the fuel cell units (for example, optimizing their lifespans). Also, for example, the control device 50C may control a power conditioner (PCS) via the communication network to adjust the output of the photovoltaic power generation device 33 or to disconnect or connect a desired number of solar cells to or in parallel with the power grid.

[0136] However, the above is merely an example and is not limiting. For example, the controller 22 (see FIG. 3) of the power control device 20 may directly control the operation of the devices corresponding to the control devices 50A to 50C, without going through the control devices 50A to 50C. Furthermore, the power control device 20 may be integrated with the control devices 50A to 50C, in other words, equipped with the control functions of the control devices 50A to 50C, and directly control the operation of the devices corresponding to the control devices 50A to 50C.

[0137] The control devices 50A to 50C 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 50A to 50C. An example of the processing unit is a microprocessor. An example of the storage unit is a memory.

[0138] [Operation] FIGS. 11A and 11B are flowcharts showing an example of the operation (power control method) of the power control device of the second embodiment.

[0139] The following operations may be performed, for example, by the arithmetic processing unit of the controller 22 reading out a control program from the storage unit of the controller 22. However, it is not essential that the following operations be performed by the controller 22. An operator may perform some of the operations. In the following example, a case where the operations are controlled by the controller 22 will be described.

[0140] The operation of the power control device 20 in FIG. 11A will now be described.

[0141] First, in step S11, the planned value FC of the power generation power FC of the fuel cell device 31 is obtained from the power database. ｍａｉｎ The charging rate SOC of the power storage device 32, the power demand D and the solar cell-generated power PV during a sampling period (predetermined period TD) are acquired. The sampling period (TD) is set to be shorter than a predetermined time (T) described below. The "sampling period" may be, for example, about 15 minutes, but is not limited to this.

[0142] Then, in step S12, the moving average value D of the power demand D during the sampling period (predetermined period TD) is calculated. ａｖｅ and the moving average value PV of the solar cell power generation power PV ａｖｅ is calculated.

[0143] Next, in step S13, B ｐｒｅ１ is calculated by the following formula (1): ｐｒｅ１ =D ａｖｅ - (PV ａｖｅ +FC ｍａｉｎ ) ... (1)

[0144] In addition, B ｐｒｅ１ When B is greater than 0, it means the discharge power of the power storage device 32. ｐｒｅ１ When it is <0, it means the charging power of the power storage device 32.

[0145] Next, in step S14, the charging rate SOC of the power storage device 32 after a predetermined time (T) has elapsed is calculated. ｌａｔｏｒ is calculated by the following formula (2). Here, the "predetermined time (T)" is the planned value FC of the power generation power FC of the fuel cell device 31 from the viewpoint of suppressing a decrease in the life of the fuel cell device 31. ｍａｉｎ is maintained for a predetermined period T ｍａｉｎ The predetermined time (T) may be about 60 minutes, but is not limited to this. ｌａｔｏｒ = SOC - (B ｐｒｅ１ × T) / Capacity of storage device (2)

[0146] Next, in step S15A, the charging rate SOC ｌａｔｏｒ is the upper limit SOC ｕｐｐｅｒ It is determined whether it is greater than

[0147] Charging rate SOC ｌａｔｏｒ is the upper limit SOC ｕｐｐｅｒ If it is greater than B (if "Yes" in step S15A), then in step S16A, the charging power or discharging power of the power storage device 32 that satisfies the following formula (3A) is calculated. ｐｒｅ２ is calculated. ｕｐｐｅｒ = SOC - (B ｐｒｅ２ ×T) / power storage device capacity...(3A)

[0148] In addition, B ｐｒｅ２ When B is greater than 0, it means the discharge power of the power storage device 32. ｐｒｅ２ When it is <0, it means the charging power of the power storage device 32.

[0149] Next, in step S17A, a correction value FC of the power generation power FC of the fuel cell device 31 that satisfies the following formula (4A) is calculated. ｓｕｂ is calculated (FC ｓｕｂ <0). B ｐｒｅ２ =D ａｖｅ - (PV ａｖｅ +FC ｍａｉｎ +FC ｓｕｂ ) ... (4A)

[0150] Then, in step S18A, the power generation FC of the fuel cell device 31 is calculated by the following equation (5A), and the power generation FC obtained by correcting the planned value of the power generation of the fuel cell device 31 is commanded on the condition that the timing does not fall under the "predetermined period TA" and "predetermined period TB" in the second example of the first embodiment and the "predetermined period TC" in the third example of the first embodiment. FC=FC ｍａｉｎ +FC ｓｕｂ ...(5A)

[0151] On the other hand, charging rate SOC ｌａｔｏｒ is the upper limit SOC ｕｐｐｅｒ If the power generated by the fuel cell device 31 is not greater than FC ("No" in step S15A), the power generated by the fuel cell device 31 is maintained at the current state. ｓｕｂ However, the charging rate SOC ｌａｔｏｒ and upper limit SOC ｕｐｐｅｒ The charging rate SOC is determined so that it is equal to, but is not limited to, the charging rate SOC. ｌａｔｏｒ is the upper limit SOCｕｐｐｅｒ FC to be less than ｓｕｂ may be determined.

[0152] The operation of the power control device 20 in FIG. 11B will now be described.

[0153] Note that steps S11 to S14 in FIG. 11B are the same as steps S11 to S14 in FIG. 11A, and therefore a description thereof will be omitted.

[0154] In step S15B, the charging rate SOC ｌａｔｏｒ is the lower limit SOC ｌｏｗｅｒ It is determined whether it is smaller than

[0155] Charging rate SOC ｌａｔｏｒ is the lower limit SOC ｌｏｗｅｒ If it is smaller than (if "Yes" in step S15B), then in step S16B, the charging power or discharging power of the power storage device 32 that satisfies the following formula (3B) is calculated as B ｐｒｅ２ is calculated. ｌｏｗｅｒ = SOC - (B ｐｒｅ２ ×T) / power storage device capacity...(3B)

[0156] Next, in step S17B, a correction value FC of the power generation power FC of the fuel cell device 31 that satisfies the following formula (4B) is calculated. ｓｕｂ is calculated (FC ｓｕｂ >0). B ｐｒｅ２ =D ａｖｅ - (PV ａｖｅ +FC ｍａｉｎ +FC ｓｕｂ ) ... (4B)

[0157] Then, in step S18B, the power generation FC of the fuel cell device 31 is calculated by the following formula (5B), and the power generation FC obtained by correcting the planned value of the power generation of the fuel cell device 31 is commanded on the condition that the timing does not fall under the "predetermined period TA" and "predetermined period TB" in the second example of the first embodiment and the "predetermined period TC" in the third example of the first embodiment. FC=FC ｍａｉｎ +FC ｓｕｂ ... (5B)

[0158] On the other hand, charging rate SOC ｌａｔｏｒ is the lower limit SOC ｌｏｗｅｒIf the power generated by the fuel cell device 31 is not smaller than FC (if "No" in step S15B), the power generated by the fuel cell device 31 is maintained as it is. ｓｕｂ However, the charging rate SOC ｌａｔｏｒ and upper limit SOC ｌｏｗｅｒ The charging rate SOC is determined so that it is equal to, but is not limited to, the charging rate SOC. ｌａｔｏｒ is the lower limit SOC ｌｏｗｅｒ FC to become bigger ｓｕｂ may be determined.

[0159] The effects and advantages of the power control method, power control device 20, and power supply system 10 of this embodiment can be easily understood from the description of the effects and advantages of the power control device 20 and power supply system 10 of the first embodiment, so further explanation will be omitted.

[0160] Other than the above-mentioned features, the power control method, power control device 20, and power supply system 10 of this embodiment may be the same as those of the first embodiment and any of the first to fourth examples of the first embodiment.

[0161] The first embodiment, the first to fourth examples of the first embodiment, and the second 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.

[0162] One embodiment of the present disclosure can be used in a power control method, a power control device, and a power supply system that can reduce the possibility that a power storage device will be fully charged or fully discharged compared to conventional methods.

[0163] 10: Power supply system 20: Power control device 21: Storage device 22: Controller 30: Distributed power supply system 31: Fuel cell device 32: Power storage device 33: Photovoltaic power generation device 40: Power load 50A: Control device 50B: Control device 50C: Control device 130: Distributed power supply system

Claims

1. A power control method comprising the steps of: when supplying power to a power load of an electric power consumer from a distributed power supply system including a fuel cell device and a power storage device, controlling the power generation power of the fuel cell device to a planned value of the power generation power of the fuel cell device; and, while performing the control, performing a first correction to decrease the planned value when the charging rate of the power storage device after a predetermined time estimated based on the planned value is greater than an upper limit value that is less than 100%, or performing a second correction to increase the planned value when the charging rate of the power storage device after a predetermined time estimated based on the planned value is less than a lower limit value that is greater than 0%.

2. The power control method according to claim 1, wherein a first specified period during which the first correction or the second correction is maintained is shorter than a second specified period during which the planned value is maintained.

3. The power control method according to claim 1, wherein the first correction or the second correction is not executed during a third specified period before the planned value is switched or during a fourth specified period after the planned value is switched.

4. A power control method as described in claim 3, wherein the third specified period or the fourth specified period is longer than the time required for the output of the fuel cell device to reach the planned value after the planned value is switched.

5. The power control method according to claim 1, wherein the first correction or the second correction is not executed for a fifth predetermined period after starting execution of the first correction or the second correction.

6. The power control method of claim 1, wherein the distributed power system further comprises a photovoltaic power generation device, and when the control is being performed, the charging rate of the power storage device after a predetermined time period is estimated from the difference between an actual value of the power demand of the power consumer in the immediately preceding sixth predetermined period and the sum of the actual value of the power generated by the photovoltaic power generation device and the planned value.

7. A power control device for a distributed power supply system equipped with a fuel cell device and a power storage device, comprising: a memory for storing a planned value of the power generation power of the fuel cell device; and a controller for controlling the power generation power of the fuel cell device to the planned value of the power generation power of the fuel cell device when power is supplied from the distributed power supply system to a power load of an electricity consumer, wherein the controller, when executing the control, performs a first correction to decrease the planned value when the charging rate of the power storage device after a predetermined time estimated based on the planned value is greater than an upper limit value that is less than 100%, or a second correction to increase the planned value when the charging rate of the power storage device after a predetermined time estimated based on the planned value is less than a lower limit value that is greater than 0%.

8. A power supply system comprising: a fuel cell device; a power storage device; and the power control device according to claim 7.

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