Power storage control device

Abstract

To provide a power storage control device capable of causing a storage battery to have an ability to increase a power receiving point power of a facility while causing the storage battery to have a sufficient power supply ability to a power load of the facility at the time of a power failure.SOLUTION: A power storage control device 20 that controls an operation of a storage battery 7 provided in a facility 2 capable of receiving a power supply from a power system 1 includes: a power failure prediction part 23 that predicts a possibility of an occurrence of a system power failure in which a power supply from the power system 1 is stopped and the predicted occurrence date and time of the system power failure at a place where the facility 2 is installed; a necessary remaining amount of power storage derivation part 24 that predicts a temporal change of the predicted load power by the power load 5 provided in the facility 2 in a predetermined period after the predicted occurrence date and time, and derives a necessary remaining amount of the power storage to be stored in the storage battery 7 at the time of the predicted generation date and time based on the temporal change of the predicted load power; and an information output part 25 that outputs an instruction to a control part 6 that controls the operation of the storage battery 7 so that the remaining amount of the power storage of the storage battery 7 becomes the necessary remaining amount of the power storage.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electricity storage control device. [Background technology]

[0002] Patent Document 1 (JP 2021-132506 A) describes a charge control method for a home equipped with a storage battery, in which the storage battery is fully charged before a typhoon-related rainstorm reaches the home in preparation for the risk of a power outage. This allows the residents of the home to continue living a nearly normal life even if a power outage actually occurs. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-132506 Summary of the Invention [Problem to be solved by the invention]

[0004] When a storage battery is installed in a facility such as a residence or business that can receive power from the power grid, the battery can be used not only to consume the power of the storage battery for the power load of the facility as in Patent Document 1, but also to operate the storage battery in accordance with a request from the business operator. For example, when a facility receives a request from a general electricity transmission and distribution business operator, an electricity retailer, an aggregator, or the like to adjust the power at the facility's power receiving point, the storage battery can be operated to charge or discharge to adjust the power at the power receiving point in accordance with the request.

[0005] However, as described in Patent Document 1, if the remaining amount of stored electricity in the storage battery is fully charged before a power outage occurs, the storage battery cannot be charged any further. Therefore, even if a request is made to increase the power at the power receiving point of a facility between the time when the storage battery is fully charged and the time when a power outage actually occurs, the power at the power receiving point cannot be increased by charging the storage battery in response to the request.

[0006] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a storage control device that can provide a storage battery with sufficient power supply capacity to the facility's power load during a power outage, while also providing the storage battery with the ability to increase the facility's power receiving point power. [Means for solving the problem]

[0007] A characteristic configuration of a power storage control device according to the present invention for achieving the above object is a power storage control device that controls the operation of a storage battery provided in a facility that can receive power supply from a power grid, A power outage prediction unit that predicts the possibility of a grid power outage occurring in a location where the facility is installed, in which power supply from the power grid is stopped, and the predicted date and time of the grid power outage; a required remaining power storage amount deriving unit that predicts a time transition of a predicted load power due to an electric power load installed in the facility for a predetermined period after the predicted occurrence date and time, and derives a required remaining power storage amount that should be stored in the storage battery at the time of the predicted occurrence date and time based on the time transition of the predicted load power; The power supply system further includes an information output unit that outputs instructions to a control unit that controls the operation of the storage battery so that the remaining amount of stored power of the storage battery reaches the required remaining amount of stored power. Here, the required remaining power storage amount deriving unit may predict the time transition of the predicted load power based on a time transition of a past load power of the power load.

[0008] According to the above characteristic configuration, the required remaining power storage deriving unit predicts the temporal change in predicted load power due to the power load installed in the facility for a predetermined period after the predicted occurrence date and time, and derives the required remaining power storage amount that the storage battery should have at the time of the predicted occurrence date and time based on the temporal change in the predicted load power.The information output unit then outputs instructions to a control unit that controls the operation of the storage battery so that the remaining power storage amount of the storage battery becomes the required remaining power storage amount.As a result, the storage battery stores the amount of power that is expected to be necessary for the predetermined period after the grid power outage occurs. In addition, since the remaining amount of electricity stored in the storage battery is not simply controlled to be fully charged, if the required remaining amount of electricity is less than the full charge state, the storage battery still has the capacity to be charged even after the required remaining amount of electricity is charged and charging is stopped. Therefore, if the facility receives a request from a general electricity transmission and distribution company, an electricity retailer, an aggregator, etc. to increase the facility's receiving point power, it can charge the storage battery in response to the request. Therefore, it is possible to provide a power storage control device that allows the storage battery to have sufficient power supply capacity to the power load of the facility during a power outage, while also allowing the storage battery to have the capacity to increase the power at the power receiving point of the facility.

[0009] Another characteristic configuration of the storage control device of the present invention is that the information output unit outputs instructions to the control unit so that the remaining amount of storage in the storage battery is maintained at the required remaining amount of storage until the grid power outage occurs, or, if the grid power outage does not occur, until the predicted end date and time of the grid power outage predicted by the power outage prediction unit.

[0010] According to the above characteristic configuration, it is expected that the remaining storage capacity of the facility's storage battery will maintain the required remaining storage capacity until a grid power outage occurs, or, if a grid power outage does not occur, until the predicted end date and time of the grid power outage predicted by the power outage prediction unit.

[0011] Another characteristic configuration of the power storage control device according to the present invention is that the facility is provided with a power generation device including at least one of a fuel cell device and a solar cell, The required remaining battery capacity derivation unit predicts the temporal change in the predicted load power due to the power load during the specified period after the predicted occurrence date and time, predicts the temporal change in the predicted generated power by the power generation device, and derives the required remaining battery capacity that should be stored in the storage battery at the time of the predicted occurrence date and time based on the temporal change in the predicted load power and the temporal change in the predicted generated power. Here, the power generation device is configured to be able to know the load power of the power load, and the required remaining storage capacity derivation unit may predict the time trend of the predicted load power based on the past time trend of the load power at the power load obtained from the power generation device.

[0012] According to the above characteristic configuration, the required remaining battery capacity derivation unit can derive the required remaining battery capacity that the storage battery should have stored at the time of the predicted occurrence date and time based on the temporal change in the predicted load power due to the power load installed in the facility and the temporal change in the predicted power generation power of the power generation device installed in the facility over a specified period after the predicted occurrence date and time.

[0013] Another characteristic configuration of the storage control device of the present invention is that the required remaining storage capacity derivation unit predicts the time trend of the predicted power generation of the solar cell based on the time trend of the predicted amount of solar radiation at the location where the facility is installed.

[0014] According to the above characteristic configuration, the required remaining power storage amount deriving unit can accurately predict the time transition of the predicted power generation of the solar cell based on the time transition of the predicted amount of solar radiation at the location where the facility is installed. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram illustrating a configuration of a power supply system according to a first embodiment. [Figure 2] 10A and 10B are diagrams illustrating an example of temporal changes in load power, generated power, discharged power, and remaining power storage capacity. [Figure 3] FIG. 10 is a diagram illustrating a configuration of a power supply system according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] A power storage control device 20 according to an embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a diagram showing the configuration of a power supply system in which a power storage control device 20 is installed. As shown in the figure, a facility 2 such as a residence or a business office can receive a supply of power from a power grid 1. Specifically, a power line 3 installed in the facility 2 is connected to the power grid 1. Various power loads 5, such as lighting devices and air conditioners, are connected to the power line 3.

[0017] The power line 3 is connected to the power system 1 via a switch 4. Furthermore, the power measurement unit 9 can measure the power at the receiving point of the facility 2. The power at the receiving point measured by the power measurement unit 9 is transmitted to the control unit 6.

[0018] A fuel cell device 8 acting as a power generation device is also connected to the power line 3. The fuel cell device 8 can operate with a constant generated power (for example, a rated generated power) or can operate with generated power that follows the load power of the power load 5. When the fuel cell device 8 operates with generated power that follows the load power of the power load 5, for example, the fuel cell device 8 measures the power supplied from the upstream side (i.e., the power grid 1 side) using a power measurement unit 10, and adjusts the generated power that is supplied from the fuel cell device 8 to the power line 3 so that the measured power is maintained at a predetermined value that is not a negative value.

[0019] Furthermore, since the fuel cell device 8 knows the generated power that it supplies to the power line 3 and the power measured by the power measurement unit 10, it can derive the load power of the power load 5. That is, "load power of the power load 5 = power measured by the power measurement unit 10 + generated power that the fuel cell device 8 supplies to the power line 3." In other words, the fuel cell device 8 as a power generation device is configured to be able to know the load power of the power load 5.

[0020] A storage battery 7 is provided in the facility 2, and the storage battery 7 is connected to the power line 3 via a power conversion circuit unit 11. The control unit 6 controls the operation of the power conversion circuit unit 11, thereby controlling the operation of the storage battery 7, i.e., the charging operation from the power line 3 to the storage battery 7 and the discharging operation from the storage battery 7 to the power line 3. For example, the control unit 6 can control the power conversion circuit unit 11 to charge the storage battery 7 from the power line 3 during nighttime hours (charging permitted time slots) when the unit price of electricity is low, and not to cause the power conversion circuit unit 11 to charge the storage battery 7 from the power line 3 during other time slots (charging not permitted time slots).

[0021] The power conversion circuit unit 11 can obtain information about the remaining amount of power stored in the storage battery 7 (for example, SOC (State of Charge)) and transmits this information to the control unit 6. Then, the control unit 6 can cause the power conversion circuit unit 11 to perform a charging operation from the power line 3 to the storage battery 7 and a discharging operation from the storage battery 7 to the power line 3 so that the remaining amount of power stored in the storage battery 7 reaches a predetermined value.

[0022] When power is being supplied from the power grid 1 to the facility 2, power is supplied to the power load 5 from at least one of the power grid 1, the storage battery 7, and the fuel cell device 8. On the other hand, when a power outage occurs and the power supply from the power grid 1 to the facility 2 stops, the switch 4 in the facility 2 opens, electrically disconnecting the power line 3 from the power grid 1. Then, power is supplied to the power load 5 from at least one of the storage battery 7 and the fuel cell device 8.

[0023] The fuel cell device 8 and the control unit 6 of the facility 2 can communicate with the power storage control device 20 via an information communication line 12. In addition, the power storage control device 20 can communicate with an information providing server 13 via the information communication line 12.

[0024] The information providing server 13 can provide, for example, weather information, disaster information, power outage information, and supply and demand information in the power grid 1. Although one information providing server 13 is depicted in the figure, there may be cases where separate servers exist that provide these pieces of information.

[0025] The power storage control device 20 is provided to control the operation of the storage battery 7 provided in the facility 2. In this embodiment, the power storage control device 20 includes an information acquisition unit 21, an information storage unit 22, a power outage prediction unit 23, a required remaining power storage amount derivation unit 24, and an information output unit 25. The power storage control device 20 is realized using, for example, a server.

[0026] The information acquisition unit 21 acquires information from the fuel cell device 8 and the control unit 6 in the facility 2. For example, the information acquisition unit 21 acquires information from the fuel cell device 8 that shows the temporal change in past load power of the power load 5. The information acquisition unit 21 also acquires information about the remaining amount of stored power in the storage battery 7 from the control unit 6. Furthermore, the information acquisition unit 21 acquires weather information, disaster information, power outage information, supply and demand information in the power grid 1, and the like from the information providing server 13.

[0027] The information acquired by the information acquisition unit 21 is stored in the information storage unit 22. The information storage unit 22 also stores information about the rated power generation of the fuel cell device 8, information about the storage capacity of the storage battery 7, and the like.

[0028] As described above, in the event of a grid power outage in which the power supply from the power grid 1 to the facility 2 is stopped, power is supplied to the power load 5 from at least one of the storage battery 7 and the fuel cell device 8. Therefore, if a grid power outage can be predicted in advance, it is preferable to increase the remaining amount of stored power in the storage battery 7 between the time the grid power outage is predicted and the time the grid power outage actually occurs. For example, the remaining amount of stored power in the storage battery 7 can be kept fully charged (i.e., a state in which it cannot be charged any further). However, a state in which the remaining amount of stored power in the storage battery 7 is kept fully charged means that the storage battery 7 does not have the adjustment capacity to respond to a request to increase the power at the receiving point of the facility 2.

[0029] Therefore, if a request to increase the power at the receiving point of facility 2 is received from, for example, a general electricity transmission and distribution utility, an electricity retailer, or an aggregator after the storage battery 7 is fully charged and before a power outage actually occurs, the storage battery 7 cannot be charged with power to increase the power at the receiving point. Thus, in order to ensure that the storage battery 7 has sufficient power supply capacity to the power load 5 of facility 2 during a power outage and also has the capacity to increase the power at the receiving point of facility 2, it is not desirable to simply fully charge the remaining amount of stored power in the storage battery 7.

[0030] Therefore, the power outage prediction unit 23 of the power storage control device 20 predicts the possibility of a grid power outage occurring where the power supply from the power grid 1 is stopped at the location where the facility 2 is installed, and the predicted date and time of the grid power outage, and the required remaining power storage derivation unit 24 predicts the temporal change in predicted load power of the power load 5 installed in the facility 2 for a predetermined period after the predicted occurrence date and time (for example, the predicted duration of the power outage, etc.), and derives the required remaining power storage that should be stored in the storage battery 7 at the time of the predicted occurrence date and time based on the temporal change in the predicted load power. For example, the required remaining power storage derivation unit 24 predicts the temporal change in the predicted load power based on information that indicates the temporal change in past load power of the power load 5, obtained from the fuel cell device 8 as a power generation device. In this embodiment, the facility 2 is provided with a fuel cell device 8 as a power generation device, and therefore the required remaining power storage deriving unit 24 predicts the temporal transition of the predicted load power of the power load 5 for a predetermined period after the prediction occurrence date and time, predicts the temporal transition of the predicted power generation by the fuel cell device 8, and derives the required remaining power storage that should be stored in the storage battery 7 as of the prediction occurrence date and time based on the temporal transition of the predicted load power and the temporal transition of the predicted power generation. Then, the information output unit 25 outputs an instruction to the control unit 6 that controls the operation of the storage battery 7 so that the remaining power storage of the storage battery 7 becomes the required remaining power storage amount.

[0031] 2 is a diagram showing an example of temporal changes in load power, generated power, discharged power, and remaining amount of stored power. In the example shown, before time t1, there are time periods in which the load power of the power load 5 is covered by both the power generated by the fuel cell device 8 and the power discharged by the storage battery 7, and time periods in which the load power is covered only by the power generated by the fuel cell device 8. In addition, there are time periods in which the remaining amount of stored power of the storage battery 7 gradually decreases as the storage battery 7 discharges, and time periods in which the remaining amount of stored power of the storage battery 7 gradually increases as the storage battery 7 charges.

[0032] Then, at time t1, the power outage prediction unit 23 of the power storage control device 20 predicts, based on information acquired from the information providing server 13, that there is a high possibility of a grid power outage in which power supply from the power grid 1 will be stopped at the location where the facility 2 is installed, and predicts the predicted date and time of the grid power outage. In the example shown in Fig. 2, the predicted date and time of the grid power outage is time t3. Therefore, the required remaining storage amount prediction unit derives the required remaining storage amount that should be stored in the storage battery 7 at the predicted occurrence date and time.

[0033] Specifically, the required remaining power storage prediction unit predicts the temporal change in the predicted power generation power of the fuel cell device 8 installed in the facility 2 for a predetermined period (between time t3 and time t4) after the predicted occurrence date and time (time t3), and derives the required remaining power storage amount that should be stored in the storage battery 7 at the time of the predicted occurrence date and time based on the temporal change in the predicted load power and the temporal change in the predicted generated power. Here, the predetermined period is the duration of the power outage predicted by the power outage prediction unit 23, a period that is determined separately from such a predicted period (for example, a uniform period of "4 hours"), etc.

[0034] For example, the required remaining storage amount deriving unit 24 predicts the temporal transition of the predicted load power for a predetermined period based on the temporal transition of the past load power of the power load 5 acquired by the information acquisition unit 21 and stored in the information storage unit 22. Furthermore, when the fuel cell device 8 operates at a constant rated power generation, the predicted power generation of the fuel cell device 8 transitions at the rated power generation. When the fuel cell device 8 performs load-following operation, the predicted power generation of the fuel cell device 8 transitions at a power that follows the load power of the power load 5 (with the rated power generation being the maximum). As a result, the required remaining storage amount deriving unit 24 can derive the temporal transition of the predicted power shortage for a predetermined period (between time t3 and time t4) after the prediction occurrence date and time (time t3) by subtracting the predicted power generation of the fuel cell device 8 from the predicted load power of the power load 5, and as a result, can derive the predicted amount of power shortage for a predetermined period (between time t3 and time t4) after the prediction occurrence date and time (time t3). Then, the predicted power shortage amount becomes the required remaining amount of power that should be stored in the storage battery 7 at the time of the prediction occurrence date and time (time t3) as shown in FIG.

[0035] The information output unit 25 of the power storage control device 20 outputs an instruction to the control unit 6 that controls the operation of the storage battery 7 so that the remaining amount of stored power in the storage battery 7 becomes the required remaining amount of stored power. As a result, charging of the storage battery 7 starts after time t1, and the storage battery 7 reaches the required remaining amount of stored power at time t2.

[0036] Furthermore, the information output unit 25 outputs an instruction to the control unit 6 so that the remaining amount of stored power in the storage battery 7 remains at the required remaining amount of stored power until a grid power outage occurs, or, if a grid power outage does not occur, until the predicted end date and time of the grid power outage predicted by the power outage prediction unit 23. As a result, after the required remaining amount of stored power is stored in the storage battery 7 at time t2, the required remaining amount of stored power is maintained in the storage battery 7.

[0037] Furthermore, if a grid power outage does not occur at time t3, which is the predicted power outage time, the required remaining amount of stored electricity is maintained in the storage battery 7 even after time t3 in the example shown in Fig. 2. Also, if a grid power outage occurs at time t3, the remaining amount of stored electricity in the storage battery 7 gradually decreases as a result of discharging from the storage battery 7 after time t3 in the example shown in Fig. 2.

[0038] As described above, the required remaining power storage deriving unit 24 predicts the temporal transition of the predicted load power due to the power load 5 installed in the facility 2 for a predetermined period after the predicted occurrence date and time, and derives the required remaining power storage amount that the storage battery 7 should have at the time of the predicted occurrence date and time based on the temporal transition of the predicted load power. Then, the information output unit 25 outputs instructions to the control unit 6, which controls the operation of the storage battery 7, so that the remaining power storage amount of the storage battery 7 becomes the required remaining power storage amount. As a result, the storage battery 7 stores the amount of power that is expected to be required for the predetermined period after the grid power outage. Furthermore, since the storage battery 7 is not controlled to simply fully charge the remaining power storage amount, even if the required remaining power storage amount is less than the full charge state, there is still capacity left to charge the storage battery 7 even after the required remaining power storage amount is charged and charging is stopped. Therefore, if the facility 2 receives a request from a general electricity transmission and distribution utility, an electricity retailer, an aggregator, or the like to increase the power receiving point of the facility 2, the storage battery 7 can charge in response to the request. Therefore, it is possible to provide a storage control device 20 that can provide the storage battery 7 with sufficient power supply capacity to the power load 5 of the facility 2 during a power outage, while also providing the storage battery 7 with the ability to increase the power at the receiving point of the facility 2.

[0039] Second Embodiment The second embodiment differs from the above-described embodiment in that a solar cell 14 is provided in the facility 2. The second embodiment will be described below, but a description of the same configuration as the above-described embodiment will be omitted.

[0040] 3 is a diagram showing the configuration of a power supply system in which the power storage control device 20 is provided. As shown in the figure, a storage battery 7 and a solar cell 14 are connected to a power conversion circuit unit 11. A control unit 6 controls the operation of the power conversion circuit unit 11 to charge the storage battery 7 with power generated by the solar cell 14 and to supply the power generated by the solar cell 14 to the power line 3.

[0041] In this embodiment, the required remaining power storage deriving unit 24 also takes into account the temporal change in the predicted power generation of the solar cell 14 when deriving the required remaining power storage. Specifically, the information acquisition unit 21 acquires information on the temporal change in the predicted amount of solar radiation at the location where the facility 2 is installed from the information providing server 13. Then, the required remaining power storage deriving unit 24 predicts the temporal change in the predicted power generation of the solar cell 14 based on the temporal change in the predicted amount of solar radiation at the location where the facility 2 is installed. Furthermore, the required remaining power storage deriving unit 24 predicts the temporal change in the predicted load power of the power load 5 and the temporal change in the predicted power generation by the power generation device (fuel cell device 8 and solar cell 14) for a predetermined period after the prediction occurrence date and time, and derives the required remaining power storage that should be stored in the storage battery 7 at the time of the prediction occurrence date and time based on the temporal change in the predicted load power and the temporal change in the predicted power generation power.

[0042] <Another embodiment> In the above embodiment, the configuration of the power storage control device 20 and the power supply system has been described using specific examples, but the configuration can be changed as appropriate.

[0043] In the above embodiment, an example has been described in which a power generation device (fuel cell device 8 and solar cell 14) is provided in the facility 2, but the present invention can also be applied to a case in which no power generation device is provided in the facility 2. Furthermore, when a power generation device is provided in the facility 2, it is sufficient that the power generation device includes at least one of the fuel cell device 8 and the solar cell 14. In other words, it is also acceptable if only the solar cell 14 is provided as the power generation device.

[0044] In the above embodiment, an example has been described in which the power storage control device 20 is realized using a server provided separately from the facility 2. However, the power storage control device 20 may be realized using a computer provided in the facility 2, for example.

[0045] The configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, as long as no contradictions arise. Furthermore, the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited to these and can be modified as appropriate within the scope that does not deviate from the purpose of the present invention. [Industrial Applicability]

[0046] The present invention can be used in a power storage control device that can provide a storage battery with sufficient power supply capacity to the power load of a facility during a power outage, while also providing the storage battery with the capacity to increase the power at the facility's power receiving point. [Explanation of symbols]

[0047] 1: Power system 2: Facilities 5: Power load 6: Control section 7: Storage battery 8:Fuel cell device 14: Solar cell 20: Power storage control device 23: Power outage prediction section 24: Required remaining battery capacity calculation section 25: Information output section

Claims

1. A power storage control device that controls the operation of a storage battery installed in a facility that can receive power from a power grid, A power outage prediction unit that predicts the possibility of a grid power outage occurring in a location where the facility is installed, in which power supply from the power grid is stopped, and the predicted date and time of the grid power outage; a required remaining power storage amount deriving unit that predicts a time transition of a predicted load power due to an electric power load installed in the facility for a predetermined period after the predicted occurrence date and time, and derives a required remaining power storage amount that should be stored in the storage battery at the time of the predicted occurrence date and time based on the time transition of the predicted load power; an information output unit that outputs an instruction to a control unit that controls operation of the storage battery so that the remaining amount of stored power of the storage battery becomes the required remaining amount of stored power.

2. 2. The power storage control device according to claim 1, wherein the information output unit outputs an instruction to the control unit so that the remaining amount of power stored in the storage battery is maintained at the required remaining amount of power until the grid power outage occurs, or, if the grid power outage does not occur, until the predicted end date and time of the grid power outage predicted by the power outage prediction unit.

3. The facility is provided with a power generation device including at least one of a fuel cell device and a solar cell, 2. The power storage control device according to claim 1, wherein the required remaining power storage amount deriving unit predicts the temporal change in the predicted load power due to the power load during the specified period after the predicted occurrence date and time, predicts the temporal change in the predicted power generation by the power generation device, and derives the required remaining power storage amount that the storage battery should have stored at the time of the predicted occurrence date and time based on the temporal change in the predicted load power and the temporal change in the predicted power generation.

4. the power generation device is configured to be able to know the load power of the power load; The power storage control device according to claim 3 , wherein the required remaining power storage amount deriving unit predicts the time transition of the predicted load power based on the time transition of the past load power of the power load acquired from the power generation device.

5. The power storage control device according to claim 3 , wherein the required remaining power storage amount deriving unit predicts the time transition of the predicted power generation of the solar cell based on the time transition of predicted solar radiation at a location where the facility is installed.

6. The power storage control device according to any one of claims 1 to 5, wherein the required remaining power storage amount deriving unit predicts the time transition of the predicted load power based on a time transition of a past load power of the power load.

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