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

Abstract

A power control method according to the present disclosure involves, when supplying power to a power load of a power consumer from a distributed power supply system provided with a distributed power generation device and a power storage device, determining supply power of the distributed power generation device by using a first coefficient so that the supply power of the distributed power generation device will be smaller than demand power of the power consumer.

Description

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

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

[0002] Various proposals have been made for power control in distributed power systems. For example, Patent Document 1 describes controlling the output of a fuel cell so that it matches the difference between the power demand and the output of a photovoltaic power generation system, and absorbing any excess or shortage of power supply relative to power demand caused by a delay in the output fluctuation of the fuel cell by charging and discharging a storage battery.

[0003] Japanese Patent Application Laid-Open No. 2004-208426

[0004] As an example, an object of the present disclosure is to provide a power control method, a power control device, and a distributed power system that can reduce the possibility of power from a distributed power system flowing back into a power grid more than conventional methods.

[0005] In order to solve the above problem, a power control method according to one aspect of the present disclosure determines the supply power of a distributed power generation device using a first coefficient so that the supply power of the distributed power generation device is smaller than the power demand of the power consumer when power is supplied to a power load of a power consumer from a distributed power generation system including a distributed power generation device and a power storage device.

[0006] A power control device according to one embodiment of the present disclosure includes a memory device that stores the power demand of a power consumer, and a controller that, when supplying power to a power load of a power consumer from a distributed power generation system that includes a distributed power generation device and a power storage device, determines the supply power of the distributed power generation device using a first coefficient so that the supply power of the distributed power generation device is smaller than the power demand of the power consumer.

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

[0008] The power control method, power control device, and distributed power system according to one aspect of the present disclosure have the effect of reducing the possibility of power from the distributed power system flowing back into the power grid more than ever before.

[0009] FIG. 1 is a diagram illustrating an example of a distributed power supply system according to the first embodiment. FIG. 2 is a diagram illustrating an example of a power control device according to the first embodiment. FIG. 3 is a flowchart illustrating an example of the operation (power control method) of the power control device according to the first embodiment. FIG. 4A is a diagram illustrating an example of a distributed power generation device provided in a distributed power supply system according to a first example of the first embodiment. FIG. 4B is a flowchart illustrating an example of the operation of the power control device (power control method) in the first example of the first embodiment. FIG. 5A is a diagram illustrating an example of a distributed power generation device provided in a distributed power supply system according to a second example of the first embodiment. FIG. 5B is a flowchart illustrating an example of the operation of the power control device (power control method) in the second example of the first embodiment. FIG. 6A is a diagram illustrating an example of a distributed power generation device provided in a distributed power supply system according to a third example of the first embodiment. FIG. 6B is a flowchart illustrating an example of the operation of the power control device (power control method) in the third example of the first embodiment. FIG. 7A is a diagram illustrating an example of a distributed power generation device provided in a distributed power supply system according to a fourth example of the first embodiment. FIG. 7B is a flowchart illustrating an example of the operation of the power control device (power control method) in the fourth example of the first embodiment. FIG. 8A is a diagram illustrating an example of a distributed power generation device provided in a distributed power generation system according to a fifth example of the first embodiment. FIG. 8B is a flowchart illustrating an example of the operation of a power control device (power control method) in the fifth example of the first embodiment. FIG. 9A is a diagram illustrating an example of a distributed power generation device provided in a distributed power generation system according to a sixth example of the first embodiment. FIG. 9B is a flowchart illustrating an example of the operation of a power control device (power control method) in the sixth example of the first embodiment. FIG. 10A is a diagram illustrating an example of a distributed power generation device provided in a distributed power generation system according to a seventh example of the first embodiment. FIG. 10B is a flowchart illustrating an example of the operation of a power control device (power control method) in the seventh example of the first embodiment. FIG. 11A is a diagram illustrating an example of a distributed power generation device provided in a distributed power generation system according to an eighth example of the first embodiment. FIG. 11B is a flowchart illustrating an example of the operation of a power control device (power control method) in the eighth example of the first embodiment.FIG. 12A is a diagram illustrating an example of a distributed power generation device provided in a distributed power generation system according to an eleventh example of the first embodiment. FIG. 12B is a flowchart illustrating an example of the operation of a power control device (power control method) in the eleventh example of the first embodiment. FIG. 13A is a diagram illustrating an example of a distributed power generation device provided in a distributed power generation system according to a twelfth example of the first embodiment. FIG. 13B is a flowchart illustrating an example of the operation of a power control device (power control method) in the twelfth example of the first embodiment. FIG. 14A is a diagram illustrating an example of a distributed power generation device provided in a distributed power generation system according to a thirteenth example of the first embodiment. FIG. 14B is a flowchart illustrating an example of the operation of a power control device (power control method) in the thirteenth example of the first embodiment. FIG. 15A is a diagram illustrating an example of a distributed power generation device provided in a distributed power generation system according to a fourteenth example of the first embodiment. FIG. 15B is a flowchart illustrating an example of the operation of a power control device (power control method) in the fourteenth example of the first embodiment. FIG. 16A is a diagram illustrating an example of a distributed power generation device provided in a distributed power generation system according to a fifteenth example of the first embodiment. Fig. 16B is a flowchart showing an example of the operation of the power control device (power control method) in a 15th example of the first embodiment. Fig. 17A is a diagram showing an example of a distributed power generation device provided in a distributed power generation system in a 16th example of the first embodiment. Fig. 17B is a flowchart showing an example of the operation of the power control device (power control method) in the 16th example of the first embodiment. Fig. 18 is a diagram showing an example of a distributed power generation system in a second embodiment. Fig. 19A is a flowchart showing an example of the operation for determining the power generated by the fuel cell device by the power control device in the second embodiment. Fig. 19B is a flowchart showing an example of the operation for determining the power generated by the fuel cell device by the power control device in the second embodiment.

[0010] Paragraph

[0037] of Patent Document 1 discloses that when excess power generation occurs due to a load reduction or an increase in power generation, a control command is issued to reduce the fuel cell output to the required fuel cell output current calculated from the solar cell output current and the load current, and since there is a time delay until the actual output reduction, power control is performed to charge the storage device.

[0011] However, the invention described in Patent Document 1 does not fully consider the prevention of reverse power flow from the fuel cell to the power grid. For example, when the power storage device is fully charged or nearly so, a time delay in the change in the output of the fuel cell may cause a reverse power flow from the fuel cell to the power grid.

[0012] Therefore, the power control method of the first aspect of the present disclosure determines the supply power of the distributed power generation device using a first coefficient so that the supply power of the distributed power generation device is smaller than the demand power of the power consumer when supplying power to the power load of a power consumer from a distributed power generation system including a distributed power generation device and a power storage device.

[0013] According to the above, the power control method of this aspect can reduce the possibility of power from the distributed power supply system flowing back into the power grid more than ever before.

[0014] Specifically, the power control method of this aspect increases the possibility of purchasing power from the power grid, but allows this and determines the supply power of the distributed power generation devices using a first coefficient so that the supply power of the distributed power generation devices is smaller than the power demand of the power consumers. As a result, the power control method of this aspect can appropriately suppress reverse power flow of power from the distributed power generation system to the power grid, compared to when the supply power of the distributed power generation devices is not determined using the first coefficient.

[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 distributed power generation device includes a solar power generation device and a fuel cell device, and the planned value of the power generation power of the fuel cell device is determined so as to satisfy the difference between the predicted value of the power demand of the power consumer or the actual power demand value multiplied by a first coefficient α and reduced, and the predicted value of the power or the actual power generation power of the solar power generation device.

[0016] The generated power of the fuel cell device calculated from the difference between the predicted value or actual demand power of the power consumer multiplied by the first coefficient α and the reduced value and the predicted value or actual generated power of the solar power generation device (hereinafter referred to as the generated power of this embodiment) is smaller than the generated power of the fuel cell device calculated from the difference between the predicted value or actual demand power of the power consumer and the predicted value or actual generated power of the solar power generation device (hereinafter referred to as the generated power of the comparative example).

[0017] Here, the "power generated in the comparative example" corresponds to power that is unlikely to induce a reverse power flow from the distributed power generation device to the power grid. In other words, the "power generated in this embodiment" is power that is further reduced by using the first coefficient α from the power that is unlikely to induce a reverse power flow from the distributed power generation device to the power grid.

[0018] Therefore, in the power control method of this embodiment, the planned value of the generated power of the fuel cell device is determined so as to satisfy the difference between the predicted value or actual power demand of the power consumer and the value obtained by multiplying or reducing the predicted value or actual power demand of the solar power generation device by the first coefficient α, thereby making it possible to appropriately suppress the generated power of the fuel cell device from flowing back into the power grid, compared to when the planned value of the generated power of the fuel cell device is determined without reducing the predicted value or actual power demand of the power consumer.

[0019] A third aspect of the power control method of the present disclosure is a power control method according to the first or second aspect, in which the distributed power generation device includes a solar power generation device and a fuel cell device, and the power generation power of the fuel cell device may be determined by adding a planned value of the power generation power of the fuel cell device to a correction value of the planned value based on the actual power demand of the power consumer, the actual power generation power of the solar power generation device, and the planned value of the power generation power of the fuel cell device, and multiplying the result by a first coefficient β and reducing the sum.

[0020] In a case where the distributed power generation device includes a solar power generation device and a fuel cell device, the sum of the planned value of the power generation power of the fuel cell device and the correction value of the planned value corresponds to the power generation power of the fuel cell device that is unlikely to induce reverse power flow from the distributed power generation device to the power grid. In other words, the value obtained by multiplying the combined power of the planned value and the correction value of the planned value by the first coefficient β and reducing it is the power that is further reduced by using the first coefficient β from the power generation power that is unlikely to induce reverse power flow from the distributed power generation device to the power grid.

[0021] Therefore, in the power control method of this embodiment, the power generated by the fuel cell device is determined by adding a correction value for the planned value of the power generated by the fuel cell device to the planned value and multiplying the result by the first coefficient β, thereby appropriately suppressing the power generated by the fuel cell device from flowing back into the power grid, compared to when the power generated by the fuel cell device is determined without multiplying by the first coefficient β.

[0022] A fourth aspect of the power control method of the present disclosure is a power control method according to the first or second aspect, in which the distributed power generation device includes a fuel cell device, and the power generation power of the fuel cell device may be determined by adding a planned value of the power generation power of the fuel cell device to a correction value of the planned value based on the actual power demand of the power consumer and the planned value of the power generation power of the fuel cell device, and multiplying the result by a first coefficient β and reducing the result.

[0023] When the distributed power generation device includes a fuel cell device, the sum of the planned value of the power generation power of the fuel cell device and the correction value of the planned value corresponds to the power generation power of the fuel cell device that is unlikely to induce reverse power flow from the distributed power generation device to the power grid. In other words, the value obtained by multiplying the combined power of the planned value and the correction value of the planned value by the first coefficient β and reducing it is the power that is further reduced by using the first coefficient β from the power generation power that is unlikely to induce reverse power flow from the distributed power generation device to the power grid.

[0024] Therefore, in the power control method of this embodiment, the power generated by the fuel cell device is determined by adding a correction value for the planned value of the power generated by the fuel cell device to the planned value, multiplying the result by the first coefficient β, and reducing the result, thereby appropriately suppressing the power generated by the fuel cell device from flowing back into the power grid, compared to when the power generated by the fuel cell device is determined without multiplying by the first coefficient β.

[0025] A fifth aspect of the power control method of the present disclosure may be such that, in the power control method of the first or second aspect, the distributed power generation device includes a solar power generation device and a fuel cell device, and the upper power generation limit value of the solar power generation device may be determined to be a value less than the difference between the sum of the actual power demand of the power consumer and the chargeable power less than the maximum charging power of the storage device and the actual power generation power of the fuel cell device, multiplied by a first coefficient γ and then reduced.

[0026] In a case where the distributed power generation device includes a solar power generation device and a fuel cell device, a value equal to or less than the difference between the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the power storage device and the actual power generated by the fuel cell device corresponds to the power generated by the solar power generation device that is unlikely to induce a reverse power flow from the distributed power generation device to the power grid. In other words, the value obtained by multiplying the value equal to or less than the difference by the first coefficient γ is the power further reduced by the first coefficient β from the power generated by the distributed power generation device that is unlikely to induce a reverse power flow to the power grid.

[0027] Therefore, in the power control method of this embodiment, by determining the upper power generation limit value of the solar power generation device as a value obtained by multiplying a value equal to or less than the difference between the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the storage device and the actual power generation limit value of the fuel cell device by the first coefficient γ and then reducing the result, it is possible to appropriately suppress the power generated by the solar power generation device from flowing back into the power grid, compared to when the upper power generation limit value of the solar power generation device is determined without reducing the value equal to or less than the difference.

[0028] A sixth aspect of the power control method of the present disclosure may be such that, in the power control method of the first or second aspect, the distributed power generation device includes a solar power generation device, and the upper power generation limit value of the solar power generation device may be determined to be a value obtained by multiplying a value equal to or less than the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the storage device by a first coefficient γ and then reducing the result.

[0029] When the distributed power generation device includes a photovoltaic power generation device, a value equal to or less than the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the power storage device corresponds to the power generated by the photovoltaic power generation device that is unlikely to induce a reverse power flow from the distributed power generation device to the power grid. In other words, the value obtained by multiplying the value equal to or less than the sum by the first coefficient γ is the power further reduced by using the first coefficient γ from the power generated by the distributed power generation device that is unlikely to induce a reverse power flow to the power grid.

[0030] Therefore, in the power control method of this embodiment, by determining the upper power generation limit value of the solar power generation device as a value equal to or less than the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the storage device, multiplying the value by the first coefficient γ and reducing the result, the method can appropriately suppress the reverse flow of power generated by the solar power generation device to the power grid, compared to when the upper power generation limit value of the solar power generation device is determined without reducing the value equal to or less than the sum.

[0031] A seventh aspect of the power control method of the present disclosure may be such that, in the power control method of the first or second aspect, the distributed power generation device includes a solar power generation device and a fuel cell device, and the charge power or discharge power of the power storage device may be determined to be a value obtained by multiplying the difference between the actual power demand of the power consumer and the sum of the actual power generated by the solar power generation device and the actual power generated by the fuel cell device by a second coefficient δ and then reducing the result.

[0032] When the distributed power generation system includes a solar power generation system and a fuel cell system, the difference between the actual power demand of the power consumer and the sum of the actual power generated by the solar power generation system and the actual power generated by the fuel cell system corresponds to the charging power or discharging power of the power storage system that is unlikely to induce a reverse power flow from the distributed power generation system to the power grid. In other words, the value obtained by multiplying this difference by the second coefficient δ and reducing it is the power that is further reduced by using the second coefficient δ from the power that is unlikely to induce a reverse power flow from the distributed power generation system to the power grid.

[0033] Therefore, in the power control method of this embodiment, the difference between the actual power demand of the power consumer and the sum of the actual power generated by the solar power generation device and the actual power generated by the fuel cell device is multiplied by the second coefficient δ and then reduced to determine the charging power or discharging power of the power storage device.This makes it possible to appropriately suppress the supply power of the distributed power generation device from flowing back into the power grid, compared to when the charging power or discharging power of the power storage device is determined without reducing the difference.

[0034] A power control method of an eighth aspect of the present disclosure may be such that, in the power control method of the first or second aspect, the distributed power generation device includes a solar power generation device, and the charge power or discharge power of the power storage device is determined to be a value obtained by multiplying a difference between the actual power demand of the power consumer and the actual power generated by the solar power generation device by a second coefficient δ and then reducing the result.

[0035] When the distributed power generation device includes a solar power generation device, the difference between the actual power demand of the power consumer and the actual power generated by the solar power generation device corresponds to the charging power or discharging power of the power storage device that is unlikely to induce a reverse power flow from the distributed power generation device to the power grid. In other words, the value obtained by multiplying the difference by the second coefficient δ and reducing it is the power that is further reduced by using the second coefficient δ from the power that is unlikely to induce a reverse power flow from the distributed power generation device to the power grid.

[0036] Therefore, in the power control method of this embodiment, by multiplying the difference between the actual power demand of the power consumer and the actual power generation of the solar power generation device by the second coefficient δ and reducing the result to determine the charging power or discharging power of the power storage device, it is possible to appropriately suppress the supply power of the distributed power generation device from flowing back into the power grid, compared to when the charging power or discharging power of the power storage device is determined without reducing the difference.

[0037] A power control method of a ninth aspect of the present disclosure may be such that, in the power control method of the first or second aspect, the distributed power generation device includes a fuel cell device, and the charge power or discharge power of the power storage device is determined to be a value obtained by multiplying the difference between the actual power demand of the power consumer and the actual power generated by the fuel cell device by a second coefficient δ and then reducing the result.

[0038] When the distributed power generation system includes a fuel cell device, the difference between the actual power demand of the power consumer and the actual power generated by the fuel cell device corresponds to the charging power or discharging power of the power storage device that is unlikely to induce a reverse power flow from the distributed power generation system to the power grid. In other words, the value obtained by multiplying this difference by the second coefficient δ and reducing it is the power that is further reduced by using the second coefficient δ from the power that is unlikely to induce a reverse power flow from the distributed power generation system to the power grid.

[0039] Therefore, the power control method of this embodiment determines the charging power or discharging power of the power storage device by multiplying the difference between the actual power demand of the power consumer and the actual power generation power of the fuel cell device by the second coefficient δ and reducing the resulting value, thereby making it possible to appropriately suppress the supply power of the distributed power generation device from flowing back into the power grid, compared to when the charging power or discharging power of the power storage device is determined without reducing the difference.

[0040] A power control method according to a tenth aspect of the present disclosure is the power control method according to any one of the first to sixth aspects, wherein the first coefficient may vary depending on the season.

[0041] Generally, the power generated by a solar power generation device and the power demanded by a power consumer change depending on the season. Therefore, the power control method of this aspect can reduce the amount of power flowing back from the distributed power generation device to the power grid by setting the first coefficient to a desired value depending on the season, compared to when the first coefficient is constant for each season.

[0042] A power control method according to an eleventh aspect of the present disclosure is the power control method according to any one of the seventh to ninth aspects, wherein the second coefficient may vary depending on the season.

[0043] Generally, the power generated by a solar power generation device and the power demanded by a power consumer change depending on the season. Therefore, the power control method of this aspect can reduce the amount of power flowing back from the distributed power generation device to the power grid by setting the second coefficient to a desired value depending on the season, compared to when the second coefficient is constant for each season.

[0044] A power control method of a twelfth aspect of the present disclosure is the power control method of the first or second aspect, wherein the distributed power generation device includes a solar power generation device and a fuel cell device, and executes a first control in which the power generation power of the fuel cell device is determined as the power generation power of the fuel cell device by multiplying the sum of the planned value of the power generation power of the fuel cell device and the actual power demand of the power consumer, the actual power generated by the solar power generation device, and a correction value of the planned value based on the planned value of the power generation power of the fuel cell device, by a first coefficient β, or a second control in which the charge power or discharge power of the power storage device is determined as the value obtained by multiplying the difference between the actual power demand of the power consumer and the sum of the actual power generated by the solar power generation device and the actual power generated by the fuel cell device, by a second coefficient δ, and reducing the sum, wherein the first coefficient β may be smaller than the second coefficient δ.

[0045] As described above, the power control method of this aspect executes a first control in which the power generated by the fuel cell device is determined by adding a correction value for the planned value of the power generated by the fuel cell device to the value obtained by multiplying the result by a first coefficient β and reducing the result, thereby making it possible to appropriately suppress the power generated by the fuel cell device from flowing back into the power grid, compared to when control is executed in which the power generated by the fuel cell device is determined without multiplying by the first coefficient β.

[0046] Furthermore, as described above, the power control method of this aspect executes a second control in which the difference between the actual power demand of the power consumer and the sum of the actual power generated by the solar power generation device and the actual power generated by the fuel cell device is multiplied by the second coefficient δ and reduced to determine the charging power or discharging power of the power storage device. This makes it possible to appropriately suppress the supply power of the distributed power generation device from flowing back into the power grid, compared to when control is executed in which the charging power or discharging power of the power storage device is determined without reducing the difference.

[0047] If the first and second coefficients are assumed to be equal in magnitude, the effect of the first control in suppressing reverse power flow from the distributed power generation system to the power grid is likely to be greater than the effect of the second control. This is because, generally, the majority of the power demand of power consumers is met by power supplied from distributed power generation systems, with the remainder being met by charging or discharging power from a power storage device. As a result, the power generated by the fuel cell system tends to be greater than the charging or discharging power of the power storage device.

[0048] Therefore, as in the power control method of this embodiment, by making the first coefficient β in the first control smaller than the second coefficient δ in the second control, it is possible to appropriately suppress the supply power of the distributed power generation device from flowing back into the power grid, compared to when the magnitudes of the two are equal or the magnitude relationship between the two is reversed.

[0049] A power control method of a thirteenth aspect of the present disclosure is the power control method of the first or second aspect, wherein the distributed power generation device includes a fuel cell device, and performs a first control in which the power generation power of the fuel cell device is determined to be a value obtained by adding a planned value of the power generation power of the fuel cell device to a correction value of the planned value based on the actual power demand of the power consumer and the planned value of the power generation power of the fuel cell device, multiplying the result by a first coefficient β, and reducing the result; or a second control in which the charge power or discharge power of the power storage device is determined to be a value obtained by multiplying the difference between the actual power demand of the power consumer and the actual power generation power of the fuel cell device by a second coefficient δ, and reducing the result; and the first coefficient β may be smaller than the second coefficient δ.

[0050] As described above, the power control method of this aspect executes a first control in which the power generated by the fuel cell device is determined by adding a correction value for the planned value of the power generated by the fuel cell device to the value obtained by multiplying the result by a first coefficient β and reducing the result, thereby making it possible to appropriately suppress the power generated by the fuel cell device from flowing back into the power grid, compared to when control is executed in which the power generated by the fuel cell device is determined without multiplying by the first coefficient β.

[0051] Furthermore, as described above, the power control method of this aspect executes a second control in which the difference between the actual power demand of the power consumer and the actual power generation of the fuel cell device is multiplied by the second coefficient δ and reduced to determine the charging power or discharging power of the power storage device. This makes it possible to appropriately suppress the supply power of the distributed power generation device from flowing back into the power grid, compared to when control is executed to determine the charging power or discharging power of the power storage device without reducing the difference.

[0052] If the first and second coefficients are assumed to be equal in magnitude, the effect of the first control in suppressing reverse power flow from the distributed power generation system to the power grid is likely to be greater than the effect of the second control. This is because, generally, the majority of the power demand of power consumers is met by power supplied from distributed power generation systems, with the remainder being met by charging or discharging power from a power storage device. As a result, the power generated by the fuel cell system tends to be greater than the charging or discharging power of the power storage device.

[0053] Therefore, as in the power control method of this embodiment, by making the first coefficient β in the first control smaller than the second coefficient δ in the second control, it is possible to appropriately suppress the supply power of the distributed power generation device from flowing back into the power grid, compared to when the magnitudes of the two are equal or the magnitude relationship between the two is reversed.

[0054] A power control method of a fourteenth aspect of the present disclosure is the power control method of the first or second aspect, wherein the distributed power generation device includes a solar power generation device and a fuel cell device, and executes a first control in which a value equal to or less than the difference between the sum of the actual power demand of the power consumer and chargeable power equal to or less than the maximum charging power of the power storage device and the actual power generation power of the fuel cell device is multiplied by a first coefficient γ and reduced, and the result is determined as the power generation upper limit value of the solar power generation device; or a second control in which a value equal to or less than the difference between the actual power demand of the power consumer and the sum of the actual power generation power of the solar power generation device and the actual power generation power of the fuel cell device is multiplied by a second coefficient δ and reduced, and the first coefficient γ may be smaller than the second coefficient δ.

[0055] As described above, the power control method of this aspect executes a first control in which a value equal to or less than the difference between the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the power storage device, and the actual power generation power of the fuel cell device, is multiplied by a first coefficient γ and reduced, to determine the power generation upper limit value of the solar power generation device. This makes it possible to appropriately suppress the power generated by the solar power generation device from flowing back into the power grid, compared to when control is executed in which the power generation upper limit value of the solar power generation device is determined without reducing the value equal to or less than the difference.

[0056] Furthermore, as described above, the power control method of this aspect executes a second control in which the difference between the actual power demand of the power consumer and the sum of the actual power generated by the solar power generation device and the actual power generated by the fuel cell device is multiplied by the second coefficient δ and reduced to determine the charging power or discharging power of the power storage device. This makes it possible to appropriately suppress the supply power of the distributed power generation device from flowing back into the power grid, compared to when control is executed in which the charging power or discharging power of the power storage device is determined without reducing the difference.

[0057] Here, assuming that the first coefficient and the second coefficient are equal in magnitude, the effect of suppressing reverse power flow from the distributed power generation device to the power grid in the first control is likely to be greater than the effect of the second control in the second control. This is because, in general, most of the power demand of power consumers is met by power supplied from distributed power generation devices, and the remainder is met by charging or discharging power from a power storage device. As a result, the power generated by a photovoltaic power generation device tends to be greater than the charging or discharging power of the power storage device.

[0058] Therefore, as in the power control method of this embodiment, by making the first coefficient γ in the first control smaller than the second coefficient δ in the second control, it is possible to appropriately suppress the supply power of the distributed power generation device from flowing back into the power grid, compared to when the magnitudes of the two are equal or the magnitude relationship between the two is reversed.

[0059] A power control method of a fifteenth aspect of the present disclosure is the power control method of the first or second aspect, wherein the distributed power generation device includes a solar power generation device, and executes a first control in which a value equal to or less than the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the power storage device is multiplied by a first coefficient γ and reduced to determine the upper power generation limit value of the solar power generation device; or a second control in which a value equal to or less than the difference between the actual power demand of the power consumer and the actual power generation power of the solar power generation device is multiplied by a second coefficient δ and reduced to determine the charging power or discharging power of the power storage device, wherein the first coefficient γ may be smaller than the second coefficient δ.

[0060] As described above, the power control method of this aspect executes a first control in which a value equal to or less than the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the power storage device is multiplied by a first coefficient γ and reduced to determine the upper power generation limit value of the solar power generation device. This makes it possible to appropriately suppress the reverse flow of power generated by the solar power generation device to the power grid, compared to when control is executed in which a value equal to or less than the sum is determined to be the upper power generation limit value of the solar power generation device without reducing it.

[0061] Furthermore, as described above, the power control method of this aspect executes a second control in which the difference between the actual power demand of the power consumer and the actual power generation of the solar power generation device is multiplied by the second coefficient δ and reduced to determine the charging power or discharging power of the power storage device. This makes it possible to appropriately suppress the supply power of the distributed power generation device from flowing back into the power grid, compared to when control is executed in which the charging power or discharging power of the power storage device is determined without reducing the difference.

[0062] Here, assuming that the first coefficient and the second coefficient are equal in magnitude, the effect of suppressing reverse power flow from the distributed power generation device to the power grid in the first control is likely to be greater than the effect of the second control in the second control. This is because, in general, most of the power demand of power consumers is met by power supplied from distributed power generation devices, and the remainder is met by charging or discharging power from a power storage device. As a result, the power generated by a photovoltaic power generation device tends to be greater than the charging or discharging power of the power storage device.

[0063] Therefore, as in the power control method of this embodiment, by making the first coefficient γ in the first control smaller than the second coefficient δ in the second control, it is possible to appropriately suppress the supply power of the distributed power generation device from flowing back into the power grid, compared to when the magnitudes of the two are equal or the magnitude relationship between the two is reversed.

[0064] A sixteenth aspect of the power control method of the present disclosure is a power control method of the first aspect, wherein when the distributed power generation device includes a fuel cell device and one of the fuel cell device and the power storage device abnormally stops, the first coefficient or the second coefficient used to determine the supply power of the other of the fuel cell device and the power storage device may be changed to a value different from that before the abnormal stop.

[0065] When the distributed power generation system includes a fuel cell device, if one of the fuel cell device and the power storage device abnormally stops, the power supplied by the distributed power generation system may flow back into the power grid. Therefore, when one of the fuel cell device and the power storage device abnormally stops, the power control method of this aspect changes the first coefficient or the second coefficient used to determine the power supplied by the other of the fuel cell device and the power storage device to a desired value different from that before the abnormal stop, thereby making it possible to appropriately suppress the power supplied by the distributed power generation system from flowing back into the power grid, compared to when these coefficients are the same before and after the abnormal stop.

[0066] A power control method of a seventeenth aspect of the present disclosure is the power control method of the first aspect, wherein when the distributed power generation device includes a solar power generation device and one of the solar power generation device and the power storage device abnormally stops, the first coefficient or the second coefficient used to determine the power supply of the other of the solar power generation device and the power storage device may be changed to a value different from that before the abnormal stop.

[0067] When the distributed power generation device includes a solar power generation device, if one of the solar power generation device and the power storage device abnormally stops, the power supplied by the distributed power generation device may flow back to the power grid. Therefore, when one of the solar power generation device and the power storage device abnormally stops, the power control method of this aspect changes the first coefficient or the second coefficient used to determine the power supplied by the other of the solar power generation device and the power storage device to a desired value different from that before the abnormal stop, thereby making it possible to appropriately suppress the power supplied by the distributed power generation device from flowing back to the power grid, compared to when these coefficients are the same before and after the abnormal stop.

[0068] An eighteenth aspect of the power control device of the present disclosure includes a memory device that stores the power demand of a power consumer, and a controller that determines the supply power of the distributed power generation device using a first coefficient so that the supply power of the distributed power generation device is smaller than the power demand of the power consumer when power is supplied to the power load of the power consumer from a distributed power generation system that includes a distributed power generation device and a storage device.

[0069] With this configuration, the power control device of this aspect can reduce the possibility of power from the distributed power system flowing back into the power grid more than ever before. Note that the details of the effects achieved by the power control device of this aspect are the same as those achieved by the power control method of the first aspect, and therefore will not be described here.

[0070] A distributed power supply system according to a nineteenth aspect of the present disclosure includes a distributed power generation device, a power storage device, and the power control device according to the eighteenth aspect.

[0071] With this configuration, the distributed power supply system of this aspect can reduce the possibility of the power of the distributed power supply system flowing back into the power grid more than ever before. Note that the detailed effects of the distributed power supply system of this aspect are similar to those of the power control method of the first aspect, and therefore will not be described here.

[0072] <Further Aspects of the Present Disclosure> As long as at least one of the first coefficient α, the first coefficient β, the first coefficient γ, and the second coefficient δ is less than 1, the effect of suppressing reverse power flow from a distributed power generation apparatus to the power grid can be achieved even if the other coefficients are 1. From this perspective, the following aspects of the present disclosure can be further devised.

[0073] A twentieth aspect of the power control method of the present disclosure, when supplying power to a power load of a power consumer from a distributed power system including a solar power generation device, a fuel cell device, and a power storage device, determines the power generation power of the fuel cell device as a value obtained by adding the planned value of the power generation power of the fuel cell device to the actual power demand of the power consumer, the actual power generation power of the solar power generation device, and a correction value of the planned value based on the planned value of the power generation power of the fuel cell device, multiplying the result by the first coefficient β and reducing the result.

[0074] As described above, the power control device of this aspect can reduce the possibility of power from the distributed power system flowing back into the power grid more than ever before. Note that the details of the effects of the power control method of this aspect are similar to those of the power control method of the third aspect, and therefore will not be described here.

[0075] A power control method of a 21st aspect of the present disclosure, 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, determines the power generation power of the fuel cell device as a value obtained by adding a planned value of the power generation power of the fuel cell device to a correction value of the planned value based on the actual power demand of the power consumer and the planned value of the power generation power of the fuel cell device, multiplying the result by the first coefficient β and reducing the result.

[0076] As described above, the power control device of this aspect can reduce the possibility of power from the distributed power system flowing back into the power grid more than ever before. Note that the details of the effects of the power control method of this aspect are similar to those of the power control method of the fourth aspect, and therefore will not be described here.

[0077] A power control method of a 22nd aspect of the present disclosure, when supplying power to a power load of a power consumer from a distributed power system including a solar power generation device, a fuel cell device, and a power storage device, determines a power generation upper limit value of the solar power generation device to be a value less than the difference between the sum of the actual power demand of the power consumer and the chargeable power less than the maximum charging power of the power storage device and the actual power generation power of the fuel cell device, multiplied by the first coefficient γ and reduced.

[0078] As described above, the power control device of this aspect can reduce the possibility of power from the distributed power system flowing back into the power grid more than ever before. Note that the details of the effects of the power control method of this aspect are similar to those of the power control method of the fifth aspect, and therefore will not be described here.

[0079] A power control method of a 23rd aspect of the present disclosure, when supplying power to a power load of a power consumer from a distributed power system including a solar power generation device and a power storage device, determines a power generation upper limit value of the solar power generation device to be a value obtained by multiplying a value less than the sum of the actual power demand of the power consumer and the chargeable power less than the maximum charging power of the power storage device by the first coefficient γ and then reducing the result.

[0080] As described above, the power control device of this aspect can reduce the possibility of power from the distributed power system flowing back into the power grid more than ever before. Note that the details of the effects of the power control method of this aspect are similar to those of the power control method of the sixth aspect, and therefore will not be described here.

[0081] A power control method of a 24th aspect of the present disclosure, when supplying power to a power load of a power consumer from a distributed power system including a solar power generation device, a fuel cell device, and a power storage device, determines the charge power or discharge power of the power storage device as a value obtained by multiplying the difference between the actual power demand of the power consumer and the sum of the actual power generated by the solar power generation device and the actual power generated by the fuel cell device by a second coefficient δ and then reducing the result.

[0082] As described above, the power control device of this aspect can reduce the possibility of power from the distributed power system flowing back into the power grid more than ever before. Note that the details of the effects of the power control method of this aspect are similar to those of the power control method of the seventh aspect, and therefore will not be described here.

[0083] A power control method of a 25th aspect of the present disclosure, when supplying power to a power load of a power consumer from a distributed power system including a solar power generation device, determines the charging power or discharging power of the power storage device as a value obtained by multiplying the difference between the actual power demand of the power consumer and the actual power generated by the solar power generation device by a second coefficient δ and then reducing the result.

[0084] As described above, the power control device of this aspect can reduce the possibility of power from the distributed power system flowing back into the power grid more than ever before. Note that the details of the effects of the power control method of this aspect are similar to those of the power control method of the eighth aspect, and therefore will not be described here.

[0085] A power control method of a 26th aspect of the present disclosure, 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, determines the charging power or discharging power of the power storage device as a value obtained by multiplying the difference between the actual power demand of the power consumer and the actual power generated by the fuel cell device by a second coefficient δ and then reducing the result.

[0086] As described above, the power control device of this aspect can reduce the possibility of power from the distributed power system flowing back into the power grid more than ever before. Note that the details of the effects of the power control method of this aspect are similar to those of the power control method of the ninth aspect, and therefore will not be described here.

[0087] 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.

[0088] 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.

[0089] Furthermore, in the operation of the apparatus, the order of steps may be changed or known steps may be added as necessary.

[0090] First Embodiment [Device Configuration] Fig. 1 is a diagram illustrating an example of a distributed power supply system according to a first embodiment. Fig. 2 is a diagram illustrating an example of a power control device according to the first embodiment.

[0091] 1, a distributed power supply system 10 of this embodiment includes a power control device 20, a distributed power generation device 31, and a power storage device 32. The specific configuration of the distributed power generation device 31 will be described in an example.

[0092] The power storage device 32 is a device that stores power generated by the distributed power generation device 31 or 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. 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. Examples of the power storage device 32 include, but are not limited to, well-known secondary batteries. The power storage device 32 includes a group of storage battery units consisting of a plurality of storage battery units, and the detailed configuration of the power storage device 32 will be described in the second embodiment.

[0093] As shown in FIG. 2 , the power control device 20 includes a storage unit 21 and a controller 22 .

[0094] The storage device 21 is a memory for storing the power demand of the power consumer.

[0095] Here, the "power consumer" is the owner of the power load 40 that receives the power supply service generated by the distributed power system 10. Examples of the "power consumer" include, but are not limited to, factories, stores, and general households.

[0096] When power is supplied from the distributed power system 10 to the power load 40 of the power consumer, the controller 22 determines the supply power of the distributed power generation device 31 using the first coefficient so that the supply power of the distributed power generation device 31 is smaller than the power demand of the power consumer. A specific example of the "first coefficient" will be described in the examples.

[0097] 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.

[0098] [Operation] FIG. 3 is a flowchart showing an example of the operation (power control method) of the power control device of the first embodiment.

[0099] The following operations may be performed, for example, by the arithmetic processing unit of the controller 22 of the power control device 20 reading out a control program from the storage unit of the controller 22. However, it is not necessarily required 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.

[0100] First, in step S1, power is supplied from the distributed power system 10 to the power load 40 of the power consumer.

[0101] Next, in step S2, the supply power of the distributed power generation device 31 is determined using a first coefficient so that the supply power is smaller than the power demand of the power consumer.

[0102] According to the present embodiment described above, the possibility of the power of the distributed power system 10 flowing back into the power grid can be reduced more than ever before.

[0103] Specifically, in this embodiment, although there is a high possibility that power will be purchased from the power grid, this is tolerated and the supply power of the distributed power generation device 31 is determined using the first coefficient so that the supply power of the distributed power generation device 31 is smaller than the power demand of the power consumer. As a result, in this embodiment, it is possible to appropriately suppress the supply power of the distributed power generation device 31 from flowing back to the power grid, compared to when the supply power of the distributed power generation device 31 is not determined using the first coefficient.

[0104] First Example The power control method of this example is the same as that of the first embodiment, except for the configuration of the distributed power generation device 31 and the control content of the controller 22, which will be described below.

[0105] FIG. 4A is a diagram showing an example of a distributed power generation device provided in a distributed power generation system of a first example of the first embodiment.

[0106] In the example shown in FIG. 4A, the distributed power generation system 31 includes a solar power generation system 31A and a fuel cell system 31B.

[0107] The solar power generation device 31A generates power by converting light energy from sunlight into electric power under the control of the power control device 20. The electric power generated by the solar power generation device 31A is supplied to the power load 40, the power grid, or the power storage device 32. A well-known device can be used as the solar power generation device 31A.

[0108] The fuel cell device 31B 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 31B is supplied to a power load 40, a power system, or a power storage device 32. A well-known device can be used as the fuel cell device 31B. An example of the hydrogen supply source is a hydrogen storage tank, but is not limited to this.

[0109] The distributed power generation system 31 may be, for example, a system that supplies large amounts of power to a power grid. In this case, the solar power generation system 31A and the fuel cell system 31B each include a solar cell group consisting of a plurality of solar cells including a solar cell panel, and a fuel cell unit group consisting of a plurality of fuel cell units including a fuel cell stack. The detailed configuration of such a distributed power generation system 31 will be described in a second embodiment.

[0110] FIG. 4B is a flowchart showing an example of the operation of the power control device (power control method) in the first example of the first embodiment.

[0111] The following operations may be performed, for example, by the arithmetic processing unit of the controller 22 (see FIG. 2 ) of the power control device 20 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.

[0112] First, in step S1, power is supplied from the distributed power system 10 to the power load 40 of the power consumer.

[0113] Next, in step S2A, a planned value for the power generation of the fuel cell device 31B is determined so as to satisfy the difference between the predicted value or actual power generation of the photovoltaic power generation device 31A and a value obtained by multiplying the predicted value or actual power demand of the power consumer by the first coefficient α and then reducing the result. The actual power demand of the power consumer is, in other words, the actual value of the power demand of the power consumer. The actual power generation of the photovoltaic power generation device 31A is, in other words, the actual value of the power generation of the photovoltaic power generation device 31A.

[0114] Here, for example, if the power load 40 of the power consumer is a power consumption facility in a factory, the "predicted value of the power demand of the power consumer" can be determined appropriately from actual factory operation data indicating past operating days or non-operating days of the factory stored in the memory 21 and actual data of the power consumption of the power load 40 corresponding to the operating days or non-operating days of the factory. The "actual power demand of the power consumer" is the actual value of the power consumed by the power load 40, and may be the latest actual value data of the power consumption of the power load 40 stored in the memory 21, or may be a moving average value of the most recent actual value data of the power consumption of the power load 40 sampled at an appropriate sampling period and stored in the memory 21.

[0115] The "predicted value of the power of the solar power generation device 31A" can be determined as appropriate from past weather data and the like stored in the memory 21. The "actual power generated by the solar power generation device 31A" may be the latest performance value data of the power generated by the solar power generation device 31A stored in the memory 21, or may be a moving average value of the most recent performance data of the power generated by the solar power generation device 31A sampled at an appropriate sampling period and stored in the memory 21.

[0116] The information indicating the "planned value of the power generation power of the fuel cell device 31B" determined in step S2A may be transmitted to a controller of the fuel cell device 31B via a communication network. An example of such a controller is the control device 50B described in the second embodiment, but is not limited to this.

[0117] The "first coefficient α" is a coefficient for underestimating the predicted value or actual power demand of the power consumer compared to actual data when determining the planned value of the power generation power of the fuel cell device 31B, and may be an appropriate numerical value less than "1" that can be specified by a user or the like. The users include direct and indirect users of the power control device 20. An example of a direct user of the power control device 20 is the administrator of the power control device 20. An example of an indirect user of the power control device 20 is the owner of the distributed power system 10. Such an owner may be the power consumer or a power generation business that supplies power to the power consumer using the distributed power system 10.

[0118] The generated power of the fuel cell device 31B (hereinafter referred to as the generated power in the present disclosure) calculated from the difference between the predicted value or actual demand power of the power consumer multiplied by the first coefficient α and reduced, and the predicted value or actual generated power of the solar power generation device 31A is smaller than the generated power of the fuel cell device 31B (hereinafter referred to as the generated power in the comparative example) calculated from the difference between the predicted value or actual demand power of the power consumer and the predicted value or actual generated power of the solar power generation device 31A.

[0119] Here, the "power generated in the comparative example" corresponds to power that is unlikely to induce a reverse power flow from the distributed power generation device 31 to the power grid. In other words, the "power generated in the present disclosure" is power that is further reduced by using the first coefficient α from the power that is unlikely to induce a reverse power flow from the distributed power generation device 31 to the power grid.

[0120] Therefore, in this embodiment, the planned value of the generated power of the fuel cell device 31B is determined so as to satisfy the difference between the value obtained by multiplying the predicted value or actual demand power of the power consumer by the first coefficient α and reducing it, and the predicted value or actual generated power of the solar power generation device 31A.This makes it possible to appropriately suppress the generated power of the fuel cell device 31B from flowing back into the power grid, compared to when the planned value of the generated power of the fuel cell device 31B is determined without reducing the predicted value or actual demand power of the power consumer.

[0121] The power control method, power control device 20, and distributed power system 10 of this embodiment may be the same as those of the first embodiment except for the above-mentioned features.

[0122] Second Example The power control method of this example is the same as that of the first embodiment, except for the configuration of the distributed power generation device 31 and the control content of the controller 22, which will be described below.

[0123] FIG. 5A is a diagram showing an example of a distributed power generation device provided in a distributed power generation system according to a second example of the first embodiment.

[0124] In the example shown in Figure 5A, the distributed power generation system 31 includes a solar power generation system 31A and a fuel cell system 31B, but the configurations of the solar power generation system 31A and the fuel cell system 31B are the same as those in the first embodiment, so explanations will be omitted.

[0125] FIG. 5B is a flowchart showing an example of the operation of the power control device (power control method) in the second example of the first embodiment.

[0126] The following operations may be performed, for example, by the arithmetic processing unit of the controller 22 (see FIG. 2 ) of the power control device 20 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.

[0127] First, in step S1, power is supplied from the distributed power system 10 to the power load 40 of the power consumer.

[0128] Next, in step S2B, the planned value of the power generation of the fuel cell device 31B is added to the actual power demand of the power consumer, the actual power generation of the solar power generation device 31A, and a correction value of the planned value based on the planned value of the power generation of the fuel cell device 31B, and then multiplied by the first coefficient β and reduced, and the resulting value is determined as the power generation of the fuel cell device 31B.

[0129] Here, the "first coefficient β" is a coefficient for underestimating the "planned value of the power generated by the fuel cell device 31B plus a correction value for the planned value based on the actual power demand of the power consumer, the actual power generated by the photovoltaic power generation device 31A, and the planned value of the power generated by the fuel cell device 31B" compared to the actual data when determining the power generated by the fuel cell device 31B, and may be an appropriate numerical value less than "1" that can be designated by a user, etc. The "user" is the same as above, and detailed description thereof will be omitted. Information indicating the "power generated by the fuel cell device 31B" determined in step S2B may be transmitted to the controller of the fuel cell device 31B via a communication network, as above.

[0130] As the "correction value of the planned values ​​based on the actual power demand of the power consumer, the actual power generated by the photovoltaic power generation device 31A, and the planned values ​​of the power generated by the fuel cell device 31B," for example, the difference between the actual power demand of the power consumer and the sum of the actual power generated by the photovoltaic power generation device 31A and the planned values ​​of the power generated by the fuel cell device 31B, or the correction value FC described in the second embodiment, ｓｕｂ These can include, but are not limited to:

[0131] The "actual power demand of the power consumer" and the "actual power generated by the solar power generation device 31A" in step S2B are the same as those described above, and therefore detailed explanations thereof will be omitted.

[0132] In a case where the distributed power generation device 31 includes a solar power generation device 31A and a fuel cell device 31B, the value obtained by adding the planned value of the power generation power of the fuel cell device 31B to the corrected value of the planned value corresponds to the power generation power of the fuel cell device 31B that is unlikely to induce reverse power flow into the power grid from the distributed power generation device 31. In other words, the value obtained by multiplying the combined power of the planned value and the corrected value of the planned value by the first coefficient β and reducing it is the power that is further reduced by using the first coefficient β from the power that is unlikely to induce reverse power flow into the power grid from the distributed power generation device 31.

[0133] Therefore, in this embodiment, the generated power of the fuel cell device 31B is determined by adding the planned value of the generated power of the fuel cell device 31B to a correction value of the planned value, multiplying the result by the first coefficient β, and reducing the result.This makes it possible to appropriately prevent the generated power of the fuel cell device 31B from flowing back into the power system, compared to when the generated power of the fuel cell device 31B is determined without multiplying by the first coefficient β.

[0134] Other than the above-mentioned features, the power control method, power control device 20, and distributed power system 10 of this embodiment may be the same as those of the first embodiment or the first example of the first embodiment.

[0135] Third Example The power control method of this example is the same as that of the first embodiment, except for the configuration of the distributed power generation device 31 and the control content of the controller 22, which will be described below.

[0136] FIG. 6A is a diagram showing an example of a distributed power generation device provided in a distributed power generation system according to a third example of the first embodiment.

[0137] In the example shown in FIG. 6A, the distributed power generation system 31 includes a fuel cell system 31B, but the configuration of the fuel cell system 31B is the same as that of the first embodiment, so a description thereof will be omitted.

[0138] FIG. 6B is a flowchart showing an example of the operation of the power control device (power control method) in the third example of the first embodiment.

[0139] The following operations may be performed, for example, by the arithmetic processing unit of the controller 22 (see FIG. 2 ) of the power control device 20 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] First, in step S1, power is supplied from the distributed power system 10 to the power load 40 of the power consumer.

[0141] Next, in step S2C, the planned value of the power generation of the fuel cell device 31B is added to a correction value of the planned value based on the actual power demand of the power consumer and the planned value of the power generation of the fuel cell device 31B, and the result is multiplied by the first coefficient β and reduced, and the resulting value is determined as the power generation of the fuel cell device 31B.

[0142] Here, the "first coefficient β" is a coefficient for underestimating the "planned value of the power generation of the fuel cell device 31B plus a correction value for the planned value based on the actual power demand of the power consumer and the planned value of the power generation of the fuel cell device 31B" compared to the actual data when determining the power generation of the fuel cell device 31B, and may be an appropriate numerical value less than "1" that can be designated by a user, etc. The "user" is the same as above, and detailed description thereof will be omitted. Information indicating the "power generation of the fuel cell device 31B" determined in step S2C may be transmitted to the controller of the fuel cell device 31B via a communication network, as above.

[0143] As the "correction value of the planned value based on the actual demand power of the power consumer and the planned value of the generated power of the fuel cell device 31B", for example, the difference between the actual demand power of the power consumer and the planned value of the generated power of the fuel cell device 31B, or the correction value FC described in the second embodiment, ｓｕｂ These can include, but are not limited to:

[0144] The "actual power demand of the power consumer" in step S2C is the same as above, and therefore a detailed explanation will be omitted.

[0145] In the case where the distributed power generation device 31 includes a fuel cell device 31B, the value obtained by adding the planned value of the power generation power of the fuel cell device 31B to the corrected value of the planned value corresponds to the power generation power of the fuel cell device 31B that is unlikely to induce reverse power flow into the power grid from the distributed power generation device 31. In other words, the value obtained by multiplying the combined power of the planned value and the corrected value of the planned value by the first coefficient β and reducing it is the power that is further reduced by using the first coefficient β from the power generation power that is unlikely to induce reverse power flow into the power grid from the distributed power generation device 31.

[0146] Therefore, in this embodiment, the power generated by the fuel cell device 31B is determined by adding a correction value for the planned value of the power generated by the fuel cell device 31B to the planned value, multiplying the result by the first coefficient β, and reducing the result.This makes it possible to appropriately prevent the power generated by the fuel cell device 31B from flowing back into the power grid, compared to when the power generated by the fuel cell device 31B is determined without multiplying by the first coefficient β.

[0147] Other than the above-mentioned features, the power control method, power control device 20, and distributed power 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.

[0148] Fourth Embodiment A power control method of this embodiment is the same as that of the first embodiment, except for the configuration of a distributed power generation device 31 and the control content of a controller 22, which will be described below.

[0149] FIG. 7A is a diagram showing an example of a distributed power generation device provided in a distributed power generation system according to a fourth example of the first embodiment.

[0150] In the example shown in Figure 7A, the distributed power generation system 31 includes a solar power generation system 31A and a fuel cell system 31B, but the configurations of the solar power generation system 31A and the fuel cell system 31B are the same as those in the first embodiment, so explanations will be omitted.

[0151] FIG. 7B is a flowchart showing an example of the operation of the power control device (power control method) in the fourth example of the first embodiment.

[0152] The following operations may be performed, for example, by the arithmetic processing unit of the controller 22 (see FIG. 2 ) of the power control device 20 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.

[0153] First, in step S1, power is supplied from the distributed power system 10 to the power load 40 of the power consumer.

[0154] Next, in step S2D, the value obtained by multiplying the value less than the difference between the sum of the actual power demand of the power consumer and the chargeable power less than the maximum charging power of the storage device 32 and the actual power generation power of the fuel cell device 31B by the first coefficient γ and then reducing the result is determined as the power generation upper limit value of the solar power generation device 31A.

[0155] Here, the "first coefficient γ" is a coefficient for underestimating the "value equal to or less than the difference between the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the power storage device 32 and the actual power generation power of the fuel cell device 31B" compared to the actual data when determining the power generation upper limit of the photovoltaic power generation device 31A, and may be an appropriate numerical value less than "1" that can be designated by a user or the like. The "user" is the same as above, and detailed description thereof will be omitted. Information indicating the "power generation upper limit of the photovoltaic power generation device 31A" determined in step S2D may be transmitted to a controller of the photovoltaic power generation device 31A via a communication network. An example of such a controller may be, but is not limited to, the control device 50A described in the second embodiment.

[0156] The "maximum charging power of the power storage device 32" is the charging capacity (kW) of the power storage device 32 that is determined depending on the specifications and usage conditions of the power storage device 32. The "maximum charging power of the power storage device 32" may be transmitted from the power storage device 32 to the power control device 20 at an appropriate timing.

[0157] The "chargeable power of the power storage device 32" may be, for example, the maximum charging power, or a value less than the maximum charging power that can be designated by a user or the like.

[0158] The "actual power demand of the power consumer" in step S2D is the same as that described above, and therefore will not be described in detail. The "actual power generated by the fuel cell device 31B" may be the latest actual value data of the power generated by the fuel cell device 31B stored in the memory 21, or may be a moving average value of the most recent actual data of the power generated by the fuel cell device 31B sampled at an appropriate sampling period and stored in the memory 21.

[0159] In the case where the distributed power generation device 31 includes a solar power generation device 31A and a fuel cell device 31B, a value equal to or less than the difference between the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the power storage device 32 and the actual power generated by the fuel cell device 31B corresponds to the power generated by the solar power generation device that is unlikely to induce a reverse power flow from the distributed power generation device 31 to the power grid. In other words, the value obtained by multiplying the value equal to or less than the difference by the first coefficient γ is the power further reduced by using the first coefficient β from the power generated by the distributed power generation device 31 that is unlikely to induce a reverse power flow to the power grid.

[0160] Therefore, in this embodiment, by determining the upper power generation limit value of the solar power generation device 31A as a value obtained by multiplying a value equal to or less than the difference between the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the storage device 32 and the actual power generation limit value of the fuel cell device 31B by the first coefficient γ and then reducing the result, it is possible to appropriately suppress the power generated by the solar power generation device 31A from flowing back into the power grid, compared to when the upper power generation limit value of the solar power generation device 31A is determined without reducing the value equal to or less than the difference.

[0161] Other than the above-mentioned features, the power control method, power control device 20, and distributed power 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.

[0162] Fifth Example The power control method of this example is the same as that of the first embodiment, except for the configuration of the distributed power generation device 31 and the control content of the controller 22, which will be described below.

[0163] FIG. 8A is a diagram showing an example of a distributed power generation device provided in a distributed power generation system according to a fifth example of the first embodiment.

[0164] In the example shown in FIG. 8A, the distributed power generation system 31 includes a solar power generation system 31A, but the configuration of the solar power generation system 31A is the same as that of the first embodiment, and therefore description thereof will be omitted.

[0165] FIG. 8B is a flowchart showing an example of the operation of the power control device (power control method) in the fifth example of the first embodiment.

[0166] The following operations may be performed, for example, by the arithmetic processing unit of the controller 22 (see FIG. 2 ) of the power control device 20 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.

[0167] First, in step S1, power is supplied from the distributed power system 10 to the power load 40 of the power consumer.

[0168] Next, in step S2E, the value obtained by multiplying a value equal to or less than the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the storage device 32 by the first coefficient γ and then reducing the result is determined as the power generation upper limit value of the solar power generation device 31A.

[0169] Here, the "first coefficient γ" is a coefficient for underestimating the "value equal to or less than the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the power storage device 32" compared to the actual data when determining the power generation upper limit of the photovoltaic power generation device 31A, and may be an appropriate numerical value less than "1" that can be designated by a user or the like. The "user" is the same as above, and detailed description thereof will be omitted. Information indicating the "power generation upper limit of the photovoltaic power generation device 31A" determined in step S2E may be transmitted to the controller of the photovoltaic power generation device 31A via a communication network, as described above.

[0170] The "actual power demand of the power consumer" and the "maximum charging power of the power storage device 32" in step S2E are the same as those described above, and therefore detailed description thereof will be omitted.

[0171] When the distributed power generation device 31 includes the photovoltaic power generation device 31A, a value equal to or less than the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the power storage device 32 corresponds to the power generated by the photovoltaic power generation device 31A that is unlikely to induce a reverse power flow to the power grid from the distributed power generation device 31. In other words, the value obtained by multiplying the value equal to or less than the sum by the first coefficient γ is the power further reduced by using the first coefficient γ from the power generated by the distributed power generation device 31 that is unlikely to induce a reverse power flow to the power grid.

[0172] Therefore, in this embodiment, by determining the power generation upper limit value of the solar power generation device 31A as a value equal to or less than the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the storage device 32, multiplied by the first coefficient γ and reduced, the power generation upper limit value of the solar power generation device 31A can be appropriately prevented from flowing back into the power grid, compared to when the power generation upper limit value of the solar power generation device 31A is determined without reducing the value equal to or less than the sum.

[0173] Other than the above-mentioned features, the power control method, power control device 20, and distributed power 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.

[0174] Sixth Example The power control method of this example is the same as that of the first embodiment, except for the configuration of the distributed power generation device 31 and the control content of the controller 22, which will be described below.

[0175] FIG. 9A is a diagram showing an example of a distributed power generation device provided in a distributed power generation system according to a sixth example of the first embodiment.

[0176] In the example shown in Figure 9A, the distributed power generation system 31 includes a solar power generation system 31A and a fuel cell system 31B, but the configurations of the solar power generation system 31A and the fuel cell system 31B are the same as those in the first embodiment, so explanations will be omitted.

[0177] FIG. 9B is a flowchart showing an example of the operation of the power control device (power control method) in the sixth example of the first embodiment.

[0178] The following operations may be performed, for example, by the arithmetic processing unit of the controller 22 (see FIG. 2 ) of the power control device 20 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.

[0179] First, in step S1, power is supplied from the distributed power system 10 to the power load 40 of the power consumer.

[0180] Next, in step S2F, the difference between the actual power demand of the power consumer and the sum of the actual power generated by the solar power generation device 31A and the actual power generated by the fuel cell device 31B is multiplied by the second coefficient δ and then reduced, and the resulting value is determined as the charging power or discharging power of the storage device 32.

[0181] Here, the "second coefficient δ" is a coefficient for underestimating the "difference between the actual power demand of the power consumer and the sum of the actual power generated by the photovoltaic power generation system 31A and the actual power generated by the fuel cell system 31B" compared to the actual data when determining the charging power or discharging power of the power storage device 32, and may be an appropriate numerical value less than "1" that can be designated by a user or the like. The "user" is the same as above, and detailed description thereof will be omitted. Information indicating the "charging power or discharging power of the power storage device 32" determined in step S2F may be transmitted to a controller of the power storage device 32 via a communication network. An example of such a controller may be, but is not limited to, the control device 50C described in the second embodiment.

[0182] The "actual power demand of the power consumer," "actual power generated by the solar power generation device 31A," and "actual power generated by the fuel cell device 31B" in step S2F are the same as those described above, and detailed explanations thereof will be omitted.

[0183] In the case where the distributed power generation system 31 includes a solar power generation system 31A and a fuel cell system 31B, the difference between the actual power demand of the power consumer and the sum of the actual power generated by the solar power generation system 31A and the actual power generated by the fuel cell system 31B corresponds to the charging power or discharging power of the power storage system 32 that is unlikely to induce a reverse power flow from the distributed power generation system 31 to the power grid. In other words, the value obtained by multiplying this difference by the second coefficient δ and reducing it is the power that is further reduced by using the second coefficient δ from the power that is unlikely to induce a reverse power flow from the distributed power generation system 31 to the power grid.

[0184] Therefore, in this embodiment, the difference between the actual power demand of the power consumer and the sum of the actual power generated by the solar power generation device 31A and the actual power generated by the fuel cell device 31B is multiplied by the second coefficient δ and reduced to determine the charging power or discharging power of the storage device 32. This makes it possible to appropriately prevent the supply power of the distributed power generation device 31 from flowing back into the power grid, compared to when the charging power or discharging power of the storage device 32 is determined without reducing the difference.

[0185] Other than the above-mentioned features, the power control method, power control device 20, and distributed power system 10 of this embodiment may be the same as those of the first embodiment and any of the first to fifth examples of the first embodiment.

[0186] Seventh Example The power control method of this example is the same as that of the first embodiment, except for the configuration of the distributed power generation device 31 and the control content of the controller 22, which will be described below.

[0187] FIG. 10A is a diagram showing an example of a distributed power generation device provided in a distributed power generation system according to a seventh example of the first embodiment.

[0188] In the example shown in FIG. 10A, the distributed power generation system 31 includes a solar power generation system 31A, but the configuration of the solar power generation system 31A is the same as that of the first embodiment, and therefore description thereof will be omitted.

[0189] FIG. 10B is a flowchart showing an example of the operation of the power control device (power control method) in the seventh example of the first embodiment.

[0190] The following operations may be performed, for example, by the arithmetic processing unit of the controller 22 (see FIG. 2 ) of the power control device 20 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.

[0191] First, in step S1, power is supplied from the distributed power system 10 to the power load 40 of the power consumer.

[0192] Next, in step S2G, the difference between the actual power demand of the power consumer and the actual power generated by the solar power generation device 31A is multiplied by the second coefficient δ and the result is reduced, and the resulting value is determined as the charging power or discharging power of the storage device 32.

[0193] Here, the "second coefficient δ" is a coefficient for underestimating the "difference between the actual power demand of the power consumer and the actual power generated by the photovoltaic power generation device 31A" compared to the actual data when determining the charging power or discharging power of the power storage device 32, and may be an appropriate numerical value less than "1" that can be designated by a user or the like. The "user" is the same as above, and therefore a detailed description thereof will be omitted. Information indicating the "charging power or discharging power of the power storage device 32" determined in step S2G may be transmitted to the controller of the power storage device 32 via a communication network, as described above.

[0194] The "actual power demand of the power consumer" and the "actual power generated by the solar power generation device 31A" in step S2G are the same as those described above, and therefore detailed explanations thereof will be omitted.

[0195] When the distributed power generation device 31 includes a solar power generation device 31A, the difference between the actual power demand of the power consumer and the actual power generated by the solar power generation device 31A corresponds to the charging power or discharging power of the power storage device 32 that is unlikely to induce a reverse power flow from the distributed power generation device 31 to the power grid. In other words, the value obtained by multiplying the difference by the second coefficient δ and reducing it is the power that is further reduced by using the second coefficient δ from the power that is unlikely to induce a reverse power flow from the distributed power generation device 31 to the power grid.

[0196] Therefore, in this embodiment, by determining the charging power or discharging power of the storage device 32 as the value obtained by multiplying the difference between the actual power demand of the power consumer and the actual power generated by the solar power generation device 31A by the second coefficient δ and reducing the result, it is possible to appropriately suppress the supply power of the distributed power generation device 31 from flowing back into the power grid, compared to when the charging power or discharging power of the storage device 32 is determined without reducing the difference.

[0197] Other than the above-mentioned features, the power control method, power control device 20, and distributed power system 10 of this embodiment may be the same as those of the first embodiment and any of the first to sixth examples of the first embodiment.

[0198] Eighth Example The power control method of this example is the same as that of the first embodiment, except for the configuration of the distributed power generation device 31 and the control content of the controller 22, which will be described below.

[0199] FIG. 11A is a diagram showing an example of a distributed power generation device provided in a distributed power generation system according to an eighth example of the first embodiment.

[0200] In the example shown in FIG. 11A, the distributed power generation system 31 includes a fuel cell system 31B, but the configuration of the fuel cell system 31B is the same as that of the first embodiment, so a description thereof will be omitted.

[0201] FIG. 11B is a flowchart showing an example of the operation of the power control device (power control method) in the eighth example of the first embodiment.

[0202] The following operations may be performed, for example, by the arithmetic processing unit of the controller 22 (see FIG. 2 ) of the power control device 20 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.

[0203] First, in step S1, power is supplied from the distributed power system 10 to the power load 40 of the power consumer.

[0204] Next, in step S2H, the difference between the actual power demand of the power consumer and the actual power generated by the fuel cell device 31B is multiplied by the second coefficient δ and then reduced to determine the charging power or discharging power of the storage device 32.

[0205] Here, the "second coefficient δ" is a coefficient for underestimating the "difference between the actual power demand of the power consumer and the actual power generated by the fuel cell device 31B" compared to the actual data when determining the charging power or discharging power of the power storage device 32, and may be an appropriate numerical value less than "1" that can be designated by a user or the like. The "user" is the same as above, and a detailed description thereof will be omitted. Information indicating the "charging power or discharging power of the power storage device 32" determined in step S2H ​​may be transmitted to the controller of the power storage device 32 via a communication network, as described above.

[0206] The "actual power demand of the power consumer" and the "actual power generated by the fuel cell device 31B" in step S2H ​​are the same as those described above, and therefore detailed explanations thereof will be omitted.

[0207] When the distributed power generation system 31 includes a fuel cell system 31B, the difference between the actual power demand of the power consumer and the actual power generated by the fuel cell system 31B corresponds to the charging power or discharging power of the power storage system 32 that is unlikely to induce a reverse power flow from the distributed power generation system 31 to the power grid. In other words, the value obtained by multiplying the difference by the second coefficient δ and reducing it is the power that is further reduced by using the second coefficient δ from the power that is unlikely to induce a reverse power flow from the distributed power generation system 31 to the power grid.

[0208] Therefore, in this embodiment, by determining the charging power or discharging power of the storage device 32 as the value obtained by multiplying the difference between the actual power demand of the power consumer and the actual power generated by the fuel cell device 31B by the second coefficient δ and reducing the result, it is possible to appropriately suppress the backflow of the supply power of the distributed power generation device 31 into the power grid, compared to when the charging power or discharging power of the storage device 32 is determined without reducing the difference.

[0209] Other than the above-mentioned features, the power control method, power control device 20, and distributed power system 10 of this embodiment may be the same as those of the first embodiment and any of the first to seventh examples of the first embodiment.

[0210] Ninth Example The power control method of this example is the same as that of the first embodiment, except that the first coefficient varies depending on the season. The "first coefficient" can be easily understood from the above description, so a detailed explanation will be omitted.

[0211] As an example, the "first coefficient α," "first coefficient β," and "first coefficient γ" may be set to different values ​​depending on the season, as shown in the following Table 1. However, these values ​​are merely examples and are not limited to this example.

[0212]

[0213] Generally, the power generated by the photovoltaic power generation device 31A and the power demand of power consumers change depending on the season. Therefore, in this embodiment, by setting the first coefficient to a desired value depending on the season, the amount of power flowing back from the distributed power generation device 31 to the power grid can be reduced compared to when the first coefficient is constant for each season.

[0214] Other than the above-mentioned features, the power control method, power control device 20, and distributed power system 10 of this embodiment may be the same as those of the first embodiment and any of the first to eighth examples of the first embodiment.

[0215] (Tenth Example) The power control method of this example is the same as any of the sixth to eighth examples of the first embodiment, except that the second coefficient varies depending on the season. The "second coefficient" can be easily understood from the above description, so a detailed explanation will be omitted.

[0216] As an example, the "second coefficient δ" may be set to vary depending on the season, as shown in Table 1. However, these numerical values ​​are merely examples and are not limited to this example.

[0217] Generally, the power generated by the photovoltaic power generation device 31A and the power demand of power consumers change depending on the season. Therefore, in this embodiment, by setting the second coefficient to a desired value depending on the season, the amount of power flowing back from the distributed power generation device 31 to the power grid can be reduced compared to when the second coefficient is constant for each season.

[0218] Other than the above-mentioned features, the power control method, power control device 20, and distributed power system 10 of this embodiment may be the same as those of the first embodiment and any of the first to ninth examples of the first embodiment.

[0219] Eleventh Example The power control method of this example is the same as that of the first embodiment, except for the configuration of the distributed power generation device 31 and the control details of the controller 22, which will be described below.

[0220] FIG. 12A is a diagram showing an example of a distributed power generation device provided in a distributed power generation system according to an eleventh example of the first embodiment.

[0221] In the example shown in FIG. 12A, the distributed power generation system 31 includes a solar power generation system 31A and a fuel cell system 31B, but the configurations of the solar power generation system 31A and the fuel cell system 31B are the same as those in the first embodiment, so description thereof will be omitted.

[0222] FIG. 12B is a flowchart showing an example of the operation of the power control device (power control method) in the eleventh example of the first embodiment.

[0223] The following operations may be performed, for example, by the arithmetic processing unit of the controller 22 (see FIG. 2 ) of the power control device 20 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.

[0224] First, in step S1, power is supplied from the distributed power system 10 to the power load 40 of the power consumer.

[0225] Next, in step S2I, a first control is executed to determine the generated power of the fuel cell device 31B as a value obtained by adding the planned value of the generated power of the fuel cell device 31B to the actual power demand of the power consumer, the actual generated power of the photovoltaic power generation device 31A, and a correction value of the planned value based on the planned value of the generated power of the fuel cell device 31B, multiplying the result by a first coefficient β, and reducing the result. Alternatively, a second control is executed to determine the charging power or discharging power of the power storage device 32 as a value obtained by multiplying by a second coefficient δ the difference between the actual power demand of the power consumer and the sum of the actual generated power of the photovoltaic power generation device 31A and the actual generated power of the fuel cell device 31B. Here, the first coefficient β is smaller than the second coefficient δ.

[0226] The "first control" in step S2I can be easily understood from the description of the second embodiment, and therefore a detailed description thereof will be omitted. The "second control" in step S2I can be easily understood from the description of the sixth embodiment, and therefore a detailed description thereof will be omitted.

[0227] As described above, in this embodiment, a first control is executed to determine the power generation of the fuel cell device 31B as a value obtained by adding a correction value for the planned value to the planned value of the power generation of the fuel cell device 31B, multiplying the result by the first coefficient β, and reducing the result. This makes it possible to appropriately suppress the power generation of the fuel cell device 31B from flowing back into the power grid, compared to when control is executed to determine the power generation of the fuel cell device 31B without multiplying by the first coefficient β.

[0228] Furthermore, as described above, in this embodiment, the second control is executed to determine the charge power or discharge power of the storage device 32 as the value obtained by multiplying the difference between the actual power demand of the power consumer and the sum of the actual power generated by the solar power generation device 31A and the actual power generated by the fuel cell device 31B by the second coefficient δ and reducing the result. This makes it possible to appropriately suppress the supply power of the distributed power generation device 31 from flowing back into the power grid, compared to when control is executed to determine the charge power or discharge power of the storage device 32 without reducing the difference.

[0229] If the first and second coefficients are assumed to be equal in magnitude, the effect of the first control in suppressing reverse power flow from the distributed power generation system 31 to the power grid is likely to be greater than the effect of the second control. This is because, generally, the majority of the power demand of power consumers is met by power supplied from the distributed power generation system 31, and the remainder is met by charging or discharging power from the power storage device 32. As a result, the power generated by the fuel cell device 31B tends to be greater than the charging or discharging power of the power storage device 32.

[0230] Therefore, as in this embodiment, by making the first coefficient β in the first control smaller than the second coefficient δ in the second control, it is possible to appropriately suppress the supply power of the distributed power generation device 31 from flowing back into the power grid, compared to when the magnitudes of the two are equal or the magnitude relationship between the two is reversed.

[0231] Other than the above-mentioned features, the power control method, power control device 20, and distributed power system 10 of this embodiment may be the same as those of the first embodiment and any of the first to tenth examples of the first embodiment.

[0232] Twelfth Example The power control method of this example is the same as that of the first embodiment, except for the configuration of the distributed power generation device 31 and the control details of the controller 22, which will be described below.

[0233] FIG. 13A is a diagram showing an example of a distributed power generation device provided in a distributed power generation system according to a twelfth example of the first embodiment.

[0234] In the example shown in FIG. 13A, the distributed power generation system 31 includes a fuel cell system 31B, but the configuration of the fuel cell system 31B is the same as that of the first embodiment, so a description thereof will be omitted.

[0235] FIG. 13B is a flowchart showing an example of the operation of the power control device (power control method) in the twelfth example of the first embodiment.

[0236] The following operations may be performed, for example, by the arithmetic processing unit of the controller 22 (see FIG. 2 ) of the power control device 20 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.

[0237] First, in step S1, power is supplied from the distributed power system 10 to the power load 40 of the power consumer.

[0238] Next, in step S2J, a first control is executed to determine the generated power of the fuel cell device 31B as a value obtained by adding the planned value of the generated power of the fuel cell device 31B to a correction value of the planned value based on the actual power demand of the power consumer and the planned value of the generated power of the fuel cell device 31B, multiplying the result by a first coefficient β, and reducing the result, or a second control is executed to determine the charging power or discharging power of the power storage device 32 as a value obtained by multiplying by a second coefficient δ the difference between the actual power demand of the power consumer and the actual generated power of the fuel cell device 31B, and reducing the result, where the first coefficient β is smaller than the second coefficient δ.

[0239] The "first control" in step S2J can be easily understood from the description of the third embodiment, and therefore a detailed description thereof will be omitted. The "second control" in step S2J can be easily understood from the description of the eighth embodiment, and therefore a detailed description thereof will be omitted.

[0240] As described above, in this embodiment, a first control is executed to determine the generated power of the fuel cell device 31B as a value obtained by adding a correction value for the planned value of the generated power of the fuel cell device 31B to the value obtained by multiplying the result by the first coefficient β and reducing the result. This makes it possible to appropriately suppress the generated power of the fuel cell device 31B from flowing back into the power grid, compared to when control is executed to determine the generated power of the fuel cell device 31B without multiplying by the first coefficient β.

[0241] Furthermore, in this embodiment, as described above, a second control is executed in which the difference between the actual power demand of the power consumer and the actual power generation of the fuel cell device 31B is multiplied by the second coefficient δ and the reduced value is used to determine the charging power or discharging power of the power storage device 32. This makes it possible to appropriately suppress the supply power of the distributed power generation device 31 from flowing back into the power grid, compared to when control is executed in which the charging power or discharging power of the power storage device is determined without reducing the difference.

[0242] If the first and second coefficients are assumed to be equal in magnitude, the effect of the first control in suppressing reverse power flow from the distributed power generation system 31 to the power grid is likely to be greater than the effect of the second control. This is because, generally, the majority of the power demand of power consumers is met by power supplied from the distributed power generation system 31, and the remainder is met by charging or discharging power from the power storage device 32. As a result, the power generated by the fuel cell device 31B tends to be greater than the charging or discharging power of the power storage device 32.

[0243] Therefore, as in this embodiment, by making the first coefficient β in the first control smaller than the second coefficient δ in the second control, it is possible to appropriately suppress the supply power of the distributed power generation device 31 from flowing back into the power grid, compared to when the magnitudes of the two are equal or the magnitude relationship between the two is reversed.

[0244] Other than the above-mentioned features, the power control method, power control device 20, and distributed power system 10 of this embodiment may be the same as those of the first embodiment and any of the first to eleventh examples of the first embodiment.

[0245] Thirteenth Example The power control method of this example is the same as that of the first embodiment, except for the configuration of the distributed power generation device 31 and the control details of the controller 22, which will be described below.

[0246] FIG. 14A is a diagram showing an example of a distributed power generation device provided in a distributed power generation system according to a thirteenth example of the first embodiment.

[0247] In the example shown in Figure 14A, the distributed power generation system 31 includes a solar power generation system 31A and a fuel cell system 31B, but the configurations of the solar power generation system 31A and the fuel cell system 31B are the same as those in the first embodiment, so explanations will be omitted.

[0248] FIG. 14B is a flowchart showing an example of the operation of the power control device (power control method) in the thirteenth example of the first embodiment.

[0249] The following operations may be performed, for example, by the arithmetic processing unit of the controller 22 (see FIG. 2 ) of the power control device 20 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.

[0250] First, in step S1, power is supplied from the distributed power system 10 to the power load 40 of the power consumer.

[0251] Next, in step S2K, a first control is executed to determine the power generation upper limit of the solar power generation system 31A by multiplying a value equal to or smaller than the difference between the sum of the actual power demand of the power consumer and the chargeable power equal to or smaller than the maximum charging power of the power storage system 32 and the actual generated power of the fuel cell system 31B by a first coefficient γ, and then reducing the result. Alternatively, a second control is executed to determine the charge power or discharge power of the power storage system 32 by multiplying a value equal to or smaller than the difference between the actual power demand of the power consumer and the sum of the actual generated power of the solar power generation system 31A and the actual generated power of the fuel cell system 31B by a second coefficient δ, and then reducing the result. Here, the first coefficient γ is smaller than the second coefficient δ.

[0252] The "first control" in step S2K can be easily understood from the description of the fourth embodiment, and therefore a detailed description thereof will be omitted. The "second control" in step S2K can be easily understood from the description of the sixth embodiment, and therefore a detailed description thereof will be omitted.

[0253] As described above, in this embodiment, a first control is executed to determine the upper power generation limit of the solar power generation device 31A as a value obtained by multiplying a value equal to or less than the difference between the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the storage device 32 and the actual power generation limit of the fuel cell device 31B by a first coefficient γ, and then reducing the result. This makes it possible to appropriately suppress the power generated by the solar power generation device 31A from flowing back into the power grid, compared to when control is executed to determine the upper power generation limit of the solar power generation device 31A without reducing the value equal to or less than the difference.

[0254] Furthermore, as described above, in this embodiment, the second control is executed to determine the charge power or discharge power of the storage device 32 as the value obtained by multiplying the difference between the actual power demand of the power consumer and the sum of the actual power generated by the solar power generation device 31A and the actual power generated by the fuel cell device 31B by the second coefficient δ and reducing the result. This makes it possible to appropriately suppress the supply power of the distributed power generation device 31 from flowing back into the power grid, compared to when control is executed to determine the charge power or discharge power of the storage device 32 without reducing the difference.

[0255] If the first coefficient and the second coefficient are assumed to be equal in magnitude, the effect of the first control for suppressing reverse power flow from the distributed power generation device 31 to the power grid is likely to be greater than the effect of the second control. This is because, generally, most of the power demand of power consumers is met by the power supplied from the distributed power generation device 31, and the remainder is met by the charging power or discharging power of the power storage device 32. As a result, the power generated by the photovoltaic power generation device 31A tends to be greater than the charging power or discharging power of the power storage device 32.

[0256] Therefore, as in this embodiment, by making the first coefficient γ in the first control smaller than the second coefficient δ in the second control, it is possible to appropriately suppress the supply power of the distributed power generation device 31 from flowing back into the power grid, compared to when the magnitudes of the two are equal or the magnitude relationship between the two is reversed.

[0257] Other than the above-mentioned features, the power control method, power control device 20, and distributed power system 10 of this embodiment may be the same as those of the first embodiment and any of the first to twelfth examples of the first embodiment.

[0258] Fourteenth Example The power control method of this example is the same as that of the first embodiment, except for the configuration of the distributed power generation device 31 and the control details of the controller 22, which will be described below.

[0259] FIG. 15A is a diagram showing an example of a distributed power generation device provided in a distributed power generation system according to a fourteenth example of the first embodiment.

[0260] In the example shown in FIG. 15A, the distributed power generation system 31 includes a solar power generation system 31A, but the configuration of the solar power generation system 31A is the same as that of the first embodiment, and therefore description thereof will be omitted.

[0261] FIG. 15B is a flowchart showing an example of the operation of the power control device (power control method) in the fourteenth example of the first embodiment.

[0262] The following operations may be performed, for example, by the arithmetic processing unit of the controller 22 (see FIG. 2 ) of the power control device 20 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.

[0263] First, in step S1, power is supplied from the distributed power system 10 to the power load 40 of the power consumer.

[0264] Next, in step S2L, a first control is executed to determine the power generation upper limit of the solar power generation device 31A by multiplying a value equal to or less than the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charge power of the power storage device 32 by a first coefficient γ and reducing the result, or a second control is executed to determine the charge power or discharge power of the power storage device 32 by multiplying a difference between the actual power demand of the power consumer and the actual power generated by the solar power generation device 31A by a second coefficient δ and reducing the result, where the first coefficient γ is smaller than the second coefficient δ.

[0265] The "first control" in step S2L can be easily understood from the description of the fifth embodiment, and therefore a detailed description thereof will be omitted. The "second control" in step S2L can be easily understood from the description of the seventh embodiment, and therefore a detailed description thereof will be omitted.

[0266] As described above, in this embodiment, the first control is executed to determine the upper power generation limit value of the solar power generation device 31A as a value obtained by multiplying a value equal to or less than the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the storage device 32 by the first coefficient γ and reducing the result, thereby making it possible to appropriately suppress the reverse flow of power generated by the solar power generation device 31A to the power grid compared to when control is executed to determine the upper power generation limit value of the solar power generation device 31A as a value equal to or less than the sum without reducing it.

[0267] Furthermore, in this embodiment, as described above, the second control is executed to determine the charge power or discharge power of the storage device 32 by multiplying the difference between the actual power demand of the power consumer and the actual power generated by the solar power generation device 31A by the second coefficient δ and reducing the result, thereby making it possible to appropriately suppress the supply power of the distributed power generation device 31 from flowing back into the power grid, compared to the case where control is executed to determine the charge power or discharge power of the storage device 32 without reducing the difference.

[0268] If the first coefficient and the second coefficient are assumed to be equal in magnitude, the effect of the first control for suppressing reverse power flow from the distributed power generation device 31 to the power grid is likely to be greater than the effect of the second control. This is because, generally, most of the power demand of power consumers is met by the power supplied from the distributed power generation device 31, and the remainder is met by the charging power or discharging power of the power storage device 32. As a result, the power generated by the photovoltaic power generation device 31A tends to be greater than the charging power or discharging power of the power storage device 32.

[0269] Therefore, as in this embodiment, by making the first coefficient γ in the first control smaller than the second coefficient δ in the second control, it is possible to appropriately suppress the supply power of the distributed power generation device 31 from flowing back into the power grid, compared to when the magnitudes of the two are equal or the magnitude relationship between the two is reversed.

[0270] Other than the above-mentioned features, the power control method, power control device 20, and distributed power system 10 of this embodiment may be the same as those of the first embodiment and any of the first to thirteenth examples of the first embodiment.

[0271] Fifteenth Example The power control method of this example is the same as that of the first embodiment, except for the configuration of the distributed power generation device 31 and the control details of the controller 22, which will be described below.

[0272] FIG. 16A is a diagram showing an example of a distributed power generation device provided in a distributed power generation system according to a fifteenth example of the first embodiment.

[0273] In the example shown in FIG. 16A, the distributed power generation system 31 includes a fuel cell system 31B, but the configuration of the fuel cell system 31B is the same as that of the first embodiment, so a description thereof will be omitted.

[0274] FIG. 16B is a flowchart showing an example of the operation of the power control device (power control method) in the fifteenth example of the first embodiment.

[0275] The following operations may be performed, for example, by the arithmetic processing unit of the controller 22 (see FIG. 2 ) of the power control device 20 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.

[0276] If one of the fuel cell device 31B and the power storage device 32 abnormally stops when power is supplied from the distributed power system 10 to the power load 40 of the power consumer ("Yes" in step S3A), in step S4A, the first coefficient or the second coefficient used to determine the power supply to the other of the fuel cell device 31B and the power storage device 32 is changed to a value different from that before the abnormal stop. Specifically, when the power storage device 32 abnormally stops, the first coefficient α, the first coefficient β, or the first coefficient γ may be changed so that these coefficients are smaller than those before the abnormal stop. When the fuel cell device 31B abnormally stops, the first coefficient γ or the second coefficient δ may be changed so that these coefficients are smaller than those before the abnormal stop. Note that the "first coefficient" and "second coefficient" are the same as those described above, and detailed description thereof will be omitted.

[0277] In a case where the distributed power generation apparatus 31 includes a fuel cell apparatus 31B, if one of the fuel cell apparatus 31B and the power storage apparatus 32 abnormally stops, there may be a reverse flow of power supplied by the distributed power generation apparatus 31 to the power grid. For this reason, in this embodiment, when one of the fuel cell apparatus 31B and the power storage apparatus 32 abnormally stops, the first coefficient or the second coefficient used to determine the power supplied by the other of the fuel cell apparatus 31B and the power storage apparatus 32 is changed to a desired value different from that before the abnormal stop, thereby making it possible to appropriately suppress a reverse flow of power supplied by the distributed power generation apparatus 31 to the power grid compared to a case where these coefficients are the same before and after the abnormal stop.

[0278] Other than the above-mentioned features, the power control method, power control device 20, and distributed power system 10 of this embodiment may be the same as those of the first embodiment and any of the first to fourteenth examples of the first embodiment.

[0279] Sixteenth Example The power control method of this example is the same as that of the first embodiment, except for the configuration of the distributed power generation device 31 and the control details of the controller 22, which will be described below.

[0280] FIG. 17A is a diagram showing an example of a distributed power generation device provided in a distributed power generation system according to a sixteenth example of the first embodiment.

[0281] In the example shown in FIG. 17A, the distributed power generation system 31 includes a solar power generation system 31A, but the configuration of the solar power generation system 31A is the same as that of the first embodiment, and therefore description thereof will be omitted.

[0282] FIG. 17B is a flowchart showing an example of the operation of the power control device (power control method) in the sixteenth example of the first embodiment.

[0283] The following operations may be performed, for example, by the arithmetic processing unit of the controller 22 (see FIG. 2 ) of the power control device 20 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.

[0284] When power is supplied from the distributed power system 10 to the power load 40 of the power consumer, if one of the photovoltaic power generation device 31A and the power storage device 32 abnormally stops (if "Yes" in step S3B), in step S4B, the first coefficient or the second coefficient used to determine the power supply of the other of the photovoltaic power generation device 31A and the power storage device 32 is changed to a value different from that before the abnormal stop. Specifically, when the power storage device 32 abnormally stops, the first coefficient α, the first coefficient β, or the first coefficient γ may be changed so that these coefficients are smaller than those before the abnormal stop. When the photovoltaic power generation device 31A abnormally stops, the first coefficient α, the first coefficient β, or the second coefficient δ may be changed so that these coefficients are smaller than those before the abnormal stop. The "first coefficient" and the "second coefficient" are the same as those described above, and therefore detailed description thereof will be omitted.

[0285] In a case where the distributed power generation device 31 includes a photovoltaic power generation device 31A, if one of the photovoltaic power generation device 31A and the power storage device 32 abnormally stops, there may be a reverse flow of power supplied by the distributed power generation device 31 to the power grid. For this reason, in this embodiment, when one of the photovoltaic power generation device 31A and the power storage device 32 abnormally stops, the first coefficient or the second coefficient used to determine the power supplied by the other of the photovoltaic power generation device 31A and the power storage device 32 is changed to a desired value different from that before the abnormal stop, thereby making it possible to appropriately suppress a reverse flow of power supplied by the distributed power generation device 31 to the power grid compared to a case where these coefficients are the same before and after the abnormal stop.

[0286] Other than the above-mentioned features, the power control method, power control device 20, and distributed power system 10 of this embodiment may be the same as those of the first embodiment and any of the first to fifteenth examples of the first embodiment.

[0287] Second Embodiment [Device Configuration] Fig. 18 is a diagram showing an example of a distributed power system according to a second embodiment. In Fig. 18, for convenience, solid lines and dashed lines respectively indicate paths through which power is transmitted and paths through which signals are transmitted.

[0288] As shown in Fig. 18, the distributed power supply system 10 of this embodiment includes a power control device 20, a solar power generation device 31A, a fuel cell device 31B, a power storage device 32, and control devices 50A to 50C. That is, in the example shown in Fig. 18, the distributed power generation device 31 includes a solar power generation device 31A and a fuel cell device 31B.

[0289] 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.

[0290] 18 , the photovoltaic power generation system 31A 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, and the solar cells 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 solar cells in each group is set to an appropriate value depending on the output specifications of the distributed power system 10, etc.

[0291] The fuel cell device 31B 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 distributed power system 10, etc.

[0292] Although not shown, each of these fuel cell units is composed of a fuel cell stack that generates electricity using hydrogen, auxiliary equipment such as pumps and valves, and 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 devices may be directly controlled by the control device 50A.

[0293] The power storage device 32 includes a group of storage battery units each consisting of a plurality of storage battery units. The group of storage battery units is divided into a plurality of groups, and the plurality of storage battery 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 storage battery units in each group is set to an appropriate value depending on the output specifications of the distributed power system 10, etc.

[0294] Furthermore, the solar power generation system 31A, the fuel cell system 31B, and the power storage system 32 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.

[0295] However, the above configuration of the distributed 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 in each group. The solar cell group may be grouped by a single group of multiple solar cells, or by a single solar cell in each group. The power storage unit group may be grouped by a single group of multiple storage battery units, or by a single storage battery unit in each group.

[0296] The control devices 50A to 50C are provided corresponding to the solar power generation device 31A, the fuel cell device 31B and the power storage device 32, respectively, and are connected to the power control device 20 via a communication network.

[0297] The control device 50A may control the output of the solar power generation device 31A by controlling a power conditioner (PCS) via a communication network, or may use the power conditioner (PCS) to disconnect or connect the desired number of solar cells to the power grid.

[0298] The controller 50B may also control the output of each of these fuel cell units via the communications network to enable efficient operation (eg, optimising lifespan) of the fuel cell units.

[0299] The control device 50C may also control the charging power or discharging power of the power storage device 32 by controlling a power conditioner (PCS) via a communication network.

[0300] However, the above is merely an example and is not limiting. For example, the controller 22 (see FIG. 2) of the power control device 20 may directly control the operation of the devices corresponding to the control devices 50A-50C without going through the control devices 50A-50C. Furthermore, the power control device 20 may be integrated with the control devices 50A-50C, in other words, equipped with the control functions of the control devices 50A-50C, and directly control the operation of the devices corresponding to the control devices 50A-50C.

[0301] 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.

[0302] [Operation] FIGS. 19A and 19B are flowcharts showing an example of the operation for determining the power generated by the fuel cell device by the power control device of the second embodiment.

[0303] 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.

[0304] The operation of the power control device 20 in FIG. 19A will now be described.

[0305] First, in step S11, the planned value FC of the generated power FC of the fuel cell device 31B 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 the sampling 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.

[0306] Then, in step S12, the moving average value D of the power demand D during the sampling period is calculated. ａｖｅ and the moving average value PV of the solar cell power generation power PV ａｖｅ is calculated.

[0307] Next, in step S13, B ｐｒｅ１ is calculated by the following formula (1): ｐｒｅ１ =D ａｖｅ - (PV ａｖｅ +FC ｍａｉｎ ) ... (1)

[0308] 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.

[0309] 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) may be about 60 minutes, but is not limited to this. ｌａｔｏｒ = SOC - (B ｐｒｅ１ × T) / Capacity of storage device (2)

[0310] Next, in step S15A, the charging rate SOC ｌａｔｏｒ is the upper limit SOC ｕｐｐｅｒ It is determined whether it is greater than

[0311] Charging rate SOC ｌａｔｏｒ is the upper limit SOC ｕｐｐｅｒ If the answer to step S15A is "Yes", then in step S16A, the charging power or discharging power B 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)

[0312] 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.

[0313] Next, in step S17A, a correction value FC of the power generation power FC of the fuel cell device 31B 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)

[0314] Then, in step S18A, the generated power FC of the fuel cell device 31B is calculated by the following equation (5A), and the generated power FC is issued as a command. FC=FC ｍａｉｎ +FC ｓｕｂ ...(5A)

[0315] On the other hand, charging rate SOC ｌａｔｏｒ is the upper limit SOC ｕｐｐｅｒ If the power generated by the fuel cell device 31B is not greater than FC ("No" in step S15A), the power generated by the fuel cell device 31B is maintained as it is. 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 SOC ｕｐｐｅｒ FC to be less than ｓｕｂ may be determined.

[0316] The operation of the power control device 20 in FIG. 19B will now be described.

[0317] Note that steps S11 to S14 in FIG. 19B are the same as steps S11 to S14 in FIG. 19A, and therefore a description thereof will be omitted.

[0318] In step S15B, the charging rate SOC ｌａｔｏｒ is the lower limit SOC ｌｏｗｅｒ It is determined whether it is smaller than

[0319] Charging rate SOC ｌａｔｏｒ is the lower limit SOC ｌｏｗｅｒ (if "Yes" in step S15B), in step S16B, the charging power or discharging power B of the power storage device 32 that satisfies the following formula (3B) is calculated. ｐｒｅ２is calculated. ｌｏｗｅｒ = SOC - (B ｐｒｅ２ ×T) / power storage device capacity...(3B)

[0320] Next, in step S17B, a correction value FC of the power generation power FC of the fuel cell device 31B 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)

[0321] Then, in step S18B, the generated power FC of the fuel cell device 31B is calculated by the following equation (5B), and the generated power FC is issued as a command. FC=FC ｍａｉｎ +FC ｓｕｂ ... (5B)

[0322] On the other hand, charging rate SOC ｌａｔｏｒ is the lower limit SOC ｌｏｗｅｒ If the power generated by the fuel cell device 31B is not smaller than FC ("No" in step S15B), the power generated by the fuel cell device 31B 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.

[0323] According to the present embodiment described above, an example of the “correction value” in the second example of the first embodiment (correction value FC ｓｕｂ ) is derived as described above. In each of the above equations, PV ａｖｅ Zero (PV ａｖｅ = 0), an example of the "correction value" in the third example of the first embodiment (correction value FC ｓｕｂ ) is derived.

[0324] Other than the above-mentioned features, the power control method, power control device 20, and distributed power system 10 of this embodiment may be the same as those of the first embodiment and any of the first to sixteenth examples of the first embodiment.

[0325] The first embodiment, the first to sixteenth 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.

[0326] One aspect of the present disclosure can be used in a power control method, a power control device, and a distributed power system that can reduce the possibility of power from a distributed power system flowing back into a power grid more than before.

[0327] 10: Distributed power supply system 20: Power control device 21: Memory device 22: Controller 31: Distributed power generation device 31A: Photovoltaic power generation device 31B: Fuel cell device 32: Power storage device 40: Power load 50A: Control device 50B: Control device 50C: Control device α: First coefficient β: First coefficient γ: First coefficient δ: Second coefficient

Claims

1. A power control method, in which when power is supplied to a power load of a power consumer from a distributed power generation system including a distributed power generation device and a power storage device, the power supply of the distributed power generation device is determined using a first coefficient so that the power supply of the distributed power generation device is smaller than the power demand of the power consumer.

2. The power control method of claim 1, wherein the distributed power generation device includes a solar power generation device and a fuel cell device, and the planned value of the generated power of the fuel cell device is determined so as to satisfy the difference between the predicted value or actual generated power of the solar power generation device and a value obtained by multiplying the predicted value or actual demand power of the power consumer by the first coefficient α and reducing the value.

3. The power control method according to claim 1 or 2, wherein the distributed power generation device includes a solar power generation device and a fuel cell device, and the generated power of the fuel cell device is determined to be a value obtained by adding a planned value of the generated power of the fuel cell device to a correction value of the planned value based on the actual power demand of the power consumer, the actual generated power of the solar power generation device, and the planned value of the generated power of the fuel cell device, and multiplying the sum by the first coefficient β and reducing the sum.

4. A power control method as described in claim 1 or 2, wherein the distributed power generation device includes a fuel cell device, and the generated power of the fuel cell device is determined as a value obtained by adding a planned value of the generated power of the fuel cell device to a correction value of the planned value based on the actual power demand of the power consumer and the planned value of the generated power of the fuel cell device, and reducing the sum by multiplying the result by the first coefficient β.

5. The power control method according to claim 1 or 2, wherein the distributed power generation device includes a solar power generation device and a fuel cell device, and the power generation upper limit value of the solar power generation device is determined to be a value obtained by multiplying a value equal to or less than the difference between the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the storage device, and the actual power generation power of the fuel cell device, and reducing the result by the first coefficient γ.

6. The power control method according to claim 1 or 2, wherein the distributed power generation device includes a solar power generation device, and a value obtained by multiplying a value equal to or less than the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the storage device by the first coefficient γ and reducing the result, is determined as the power generation upper limit value of the solar power generation device.

7. The power control method according to claim 1 or 2, wherein the distributed power generation device includes a solar power generation device and a fuel cell device, and the charge power or discharge power of the power storage device is determined to be a value obtained by multiplying a difference between an actual power demand of the power consumer and a sum of an actual power generated by the solar power generation device and an actual power generated by the fuel cell device by a second coefficient δ and then reducing the result.

8. The power control method according to claim 1 or 2, wherein the distributed power generation device includes a solar power generation device, and a value obtained by multiplying a difference between an actual power demand of the power consumer and an actual power generated by the solar power generation device by a second coefficient δ and reducing the result is determined as the charging power or discharging power of the power storage device.

9. A power control method as described in claim 1 or 2, wherein the distributed power generation device includes a fuel cell device, and a value obtained by multiplying a difference between an actual power demand of the power consumer and an actual power generated by the fuel cell device by a second coefficient δ and reducing the result is determined as the charging power or discharging power of the power storage device.

10. A power control method according to any one of claims 1 to 6, wherein the first coefficient varies depending on the season.

11. A power control method according to any one of claims 7 to 9, wherein the second coefficient varies depending on the season.

12. The power control method according to claim 1 or 2, wherein the distributed power generation device includes a solar power generation device and a fuel cell device, and a first control is executed to determine the generated power of the fuel cell device as a value obtained by adding a planned value of the generated power of the fuel cell device to a correction value of the planned value based on the actual power demand of the power consumer, the actual generated power of the solar power generation device, and the planned value of the generated power of the fuel cell device, and reducing the sum by the first coefficient β, or a second control is executed to determine the charging power or discharging power of the power storage device as a value obtained by multiplying the difference between the actual power demand of the power consumer and the sum of the actual generated power of the solar power generation device and the actual generated power of the fuel cell device by the second coefficient δ, and the first coefficient β is smaller than the second coefficient δ.

13. The power control method according to claim 1 or 2, wherein the distributed power generation device includes a fuel cell device, and a first control is executed in which the generated power of the fuel cell device is determined to be a value obtained by multiplying a first coefficient β by adding a planned value of the generated power of the fuel cell device to a correction value of the planned value based on the actual power demand of the power consumer and the planned value of the generated power of the fuel cell device, and reducing the sum; or a second control is executed in which the charging power or discharging power of the power storage device is determined to be a value obtained by multiplying a difference between the actual power demand of the power consumer and the actual generated power of the fuel cell device by the second coefficient δ, and reducing the sum, wherein the first coefficient β is smaller than the second coefficient δ.

14. The power control method according to claim 1 or 2, wherein the distributed power generation device includes a solar power generation device and a fuel cell device, and a first control is executed to determine a power generation upper limit value of the solar power generation device by multiplying a value equal to or less than the difference between the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the power storage device, and the actual power generation of the fuel cell device, and reducing the result by the first coefficient γ, or a second control is executed to determine a charge power or discharge power of the power storage device by multiplying a value equal to or less than the difference between the actual power demand of the power consumer and the sum of the actual power generation of the solar power generation device and the actual power generation of the fuel cell device, and reducing the result by the second coefficient δ, wherein the first coefficient γ is smaller than the second coefficient δ.

15. The power control method according to claim 1 or 2, wherein the distributed power generation device includes a solar power generation device, and a first control is executed in which a value equal to or less than the sum of the actual power demand of the power consumer and the chargeable power equal to or less than the maximum charging power of the power storage device is multiplied by the first coefficient γ and reduced to determine a power generation upper limit value of the solar power generation device, or a second control is executed in which a value equal to or less than the difference between the actual power demand of the power consumer and the actual power generation power of the solar power generation device is multiplied by the second coefficient δ and reduced to determine a charge power or discharge power of the power storage device, and the first coefficient γ is smaller than the second coefficient δ.

16. The power control method according to claim 1, wherein the distributed power generation device includes a fuel cell device, and when one of the fuel cell device and the power storage device abnormally stops, the first coefficient or the second coefficient used in determining the power supply to the other of the fuel cell device and the power storage device is changed to a value different from that before the abnormal stop.

17. The power control method according to claim 1, wherein the distributed power generation device includes a photovoltaic power generation device, and when one of the photovoltaic power generation device and the power storage device abnormally stops, the first coefficient or the second coefficient used in determining the power supply of the other of the photovoltaic power generation device and the power storage device is changed to a value different from that before the abnormal stop.

18. A power control device comprising: a memory device that stores the power demand of a power consumer; and a controller that determines the supply power of a distributed power generation device using a first coefficient so that the supply power of the distributed power generation device is smaller than the power demand of the power consumer when power is supplied to a power load of the power consumer from a distributed power source system that includes a distributed power generation device and a power storage device.

19. A distributed power system comprising: a distributed power generation device; a power storage device; and the power control device according to claim 18.

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