Power management device and computer program

Abstract

To allow a user to select various utilization methods of power after suppressing an occurrence of a voltage deviation state.SOLUTION: A power management device includes a data acquisition part for acquiring data including generated power of distributed power supplies and power used by a load, a weather information acquisition part for acquiring weather forecast information, a prediction part for predicting generated power at least after a next day, inverse load flow power, the power used by the load, and an occurrence of a voltage deviation state, a voltage deviation forecast creation part for acquiring information of power use application on an occurrence schedule date when a voltage deviation state occurs by retrieval, and creating voltage deviation forecast including introduction information including the acquired the information of the use application and information of the load to be used for the use application, and occurrence information of the predicted voltage deviation state, and an output part for outputting the created voltage deviation forecast to other devices.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power management apparatus and a computer program. [Background technology]

[0002] Conventionally, there is known a power distribution system that combines power generated by a distributed power source such as a solar power generation device with a commercial power source, stores the power in a storage battery, and supplies the power from the commercial power source, the distributed power source, and the storage battery to devices (see, for example, Patent Document 1). Such a power distribution system is installed in a demand-side facility such as a detached house, and can sell the power generated by the distributed power source by reverse flowing it to the power grid. However, if a voltage deviation occurs in which the voltage of the power grid exceeds the upper limit voltage, the reverse flow stops. If the reverse flow stops, the power generated by the distributed power source cannot be sold, and the owner of the distributed power source may suffer economic losses.

[0003] The power management system of a power distribution system described in Patent Document 1 determines the risk of a voltage deviation state occurring according to the voltage of the power grid in order to suppress the occurrence of a voltage deviation state. If the determined risk of a voltage deviation state occurring in a few hours is low, the user is notified of the risk. On the other hand, if the risk of a voltage deviation state occurring in a few hours is high, charging of a storage battery, which is a distributed power source, is automatically performed, and the power supplied from the distributed power source to the power grid is suppressed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6481942 Summary of the Invention [Problem to be solved by the invention]

[0005] In the technology described in Patent Document 1, a user is notified and a storage battery is charged according to the risk of a voltage deviation state occurring in a few hours. However, for example, when the distributed power source is a photovoltaic power generation, the peak of the power generation amount occurs around noon. In this case, even if the user is notified of the risk of a voltage deviation state occurring a few hours before noon, the user may not be able to effectively use the power stored in the storage battery. In particular, if the user works during the day and is not at home, the time to consider how to effectively use the power when at home before work is very short, and the user may not be able to effectively use the power. In addition, Patent Document 1 lists charging a storage battery as a method of using power, but there are various other methods of using power, such as charging an electric vehicle and supplying power to home appliances.

[0006] The present invention has been made to solve at least part of the above-mentioned problems, and aims to enable users to select various ways of utilizing power while suppressing the occurrence of voltage deviation states. [Means for solving the problem]

[0007] The present invention has been made to solve at least part of the above-mentioned problems, and can be realized in the following forms.

[0008] (1) According to one aspect of the present invention, there is provided a power management device for use in a power distribution system that supplies at least one of power supplied from a power grid and power generated by a distributed power source to a load that consumes power, and stops a reverse flow of power generated by the distributed power source to the power grid when a voltage deviation state occurs in which the voltage of the power grid becomes equal to or higher than a preset upper limit voltage. The power management device includes a data acquisition unit that acquires data including a voltage change in the power grid, the power generated by the distributed power source, reverse flow power that flows reversely from the distributed power source to the power grid, and power used by the load, a weather information acquisition unit that acquires weather forecast information for at least the next day onwards, a data storage unit that stores the data acquired by the data acquisition unit and the weather forecast information acquired by the weather information acquisition unit, and calculates the power generated by the distributed power source and the reverse flow power for at least the next day onwards using the data stored in the data storage unit and the weather forecast information. the voltage deviation condition generating unit is configured to search for and obtain information on the intended use of the power on the scheduled date on which the voltage deviation condition is to occur when the prediction unit predicts that the voltage deviation condition will occur on the next day or later, and to generate a voltage deviation forecast including introduction information including the obtained information on the intended use and information on the load used for the intended use, and information on the predicted occurrence of the voltage deviation condition; and an output unit is configured to output the voltage deviation forecast generated by the voltage deviation forecast generating unit to another device.

[0009] According to this configuration, the occurrence of a voltage deviation state is predicted. The voltage deviation forecast that is created includes the recommendation information acquired by the search and information on the occurrence of a voltage deviation state. That is, the power that is scheduled to be suppressed from the power generated by the distributed power source due to the occurrence of a voltage deviation state can be used for the purpose of using the power that is output in advance based on the prediction (for example, use of home appliances such as cooking or laundry). That is, the user can use the power that was scheduled to be suppressed from the next day onwards in various ways by referring to the recommendation information. Therefore, the power that was supposed to be suppressed can be used effectively.

[0010] (2) In the power management device of the above aspect, the data acquisition unit acquires data including the charging power when a storage battery capable of storing further power is charged, the discharging power discharged from the storage battery, and the amount of stored power in the storage battery, and the prediction unit may predict the trend in the amount of stored power in the storage battery for at least the next day. According to this configuration, data on a storage battery capable of charging and discharging power is acquired. When a storage battery is present, the battery charge can be utilized, increasing the degree of freedom in terms of time to prepare for power curtailment compared to when a storage battery is not present. For example, if the power stored in the storage battery is consumed the night before, etc., to free up the battery's free capacity, power curtailment can be avoided by charging the storage battery when power curtailment occurs.

[0011] (3) The power management device of the above aspect may further include an introduction information storage unit that stores the introduction information acquired by the voltage deviation forecast creation unit, and the voltage deviation forecast creation unit may refer to the introduction information stored in the introduction information storage unit, and when the newly acquired introduction information has the same content as the previously acquired introduction information and a predetermined period of time has not elapsed since the previously acquired introduction information was acquired, acquire different introduction information, and refer to the introduction information stored in the introduction information storage unit, and create the voltage deviation forecast including the newly acquired introduction information when the newly acquired introduction information has different content from the previously acquired introduction information or when the predetermined period of time has elapsed since the previously acquired introduction information was created. According to this configuration, if the predetermined period has not elapsed, the same introduction information is not output to other devices. On the other hand, even if the acquired introduction information has the same content as the past, if the predetermined period has elapsed or the content of the acquired introduction information is different from the past, it is output to other devices as novel introduction information. As a result, the same introduction information does not have to be proposed to the user until the predetermined period has elapsed, which not only promotes the effective use of surplus power, but also provides the user with an opportunity to experience something new through the use of surplus power.

[0012] (4) In the power management device of the above aspect, the information on the intended use included in the introduction information may be information related to any one of cooking, laundry, use of an electric vehicle, and DIY (Do it yourself). According to this configuration, power usage such as cooking, laundry, electric vehicle use, and DIY consumes relatively large amounts of power but requires time to prepare. Therefore, by using this technology to prepare in advance, it becomes possible to effectively use power for the above-mentioned purposes.

[0013] (5) In the power management device of the above aspect, the voltage deviation forecast creation unit may obtain additional information by searching, which is at least one of sale information on products used when using the load and information on new products of the electrical equipment that is the load, and may further create the voltage deviation forecast that includes the additional information. According to this configuration, a voltage deviation forecast is created that includes additional information such as sale information, information on new models of equipment used as a load, etc., in addition to the power usage purpose. Therefore, by obtaining the voltage deviation forecast via another device, if the power usage purpose is cooking, for example, the user can prepare ingredients for cooking or replace old cooking equipment that they already own with new products at a lower cost.

[0014] (6) In the power management device of the above aspect, the prediction unit predicts the trend in the amount of stored electricity in the storage battery and the trend in the occurrence of the voltage deviation state for each of the seven days from the next day onwards, and the voltage deviation forecast creation unit creates the voltage deviation forecast corresponding to each of the predicted days when the occurrence of the voltage deviation state is predicted for at least one of the seven days from the predicted next day onwards, and the output unit may output the created voltage deviation forecasts for one or more days to another device all at once. According to this configuration, the voltage deviation forecast and power usage for the next seven days are output to another device. Many users have a life rhythm that consists of a seven-day week. Therefore, by outputting the voltage deviation forecast including the power usage for the next seven days to another device in advance, the user who owns the other device can make a schedule for the week in line with his or her life rhythm. As a result, the user can make more effective use of the power that was scheduled to be suppressed on the scheduled generation date.

[0015] The present invention can be realized in various forms, for example, in the form of a power distribution system, a power management device, a power management system, a power management method and a system including these devices, a computer program for executing these devices, a server device for distributing this computer program, a non-transitory storage medium on which a computer program is stored, etc. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic block diagram of a power distribution system including a power management device according to an embodiment of the present invention; [Diagram 2] 13 is a flowchart for generating a voltage deviation forecast. [Diagram 3] FIG. 13 is an explanatory diagram of a prediction of a power generation amount. [Figure 4] 11 is a flowchart for predicting a power generation amount. [Diagram 5] 13 is a flowchart of voltage deviation prediction. [Figure 6] FIG. 13 is an explanatory diagram of remaining demand. [Figure 7] 10 is a flowchart for predicting an upper limit of reverse flow power in a state in which no voltage deviation state occurs. [Figure 8] FIG. 11 is an explanatory diagram of a correlation function between reverse flow power and voltage in a state in which no voltage deviation state occurs. [Figure 9] 10 is a flowchart for predicting an upper limit of reverse flow power in a state in which a voltage deviation state occurs. [Figure 10]FIG. 11 is an explanatory diagram showing a correlation between reverse flow power and voltage data in a state in which a voltage deviation state occurs. [Figure 11] 4 is a flowchart of generating a voltage deviation forecast in the first embodiment. [Figure 12] FIG. 11 is an explanatory diagram of an example of a voltage deviation forecast. [Figure 13] FIG. 11 is a schematic block diagram of a power distribution system including a power management device according to a second embodiment. [Figure 14] 13 is a flowchart for predicting the capacity of a storage battery. [Figure 15] FIG. 11 is an explanatory diagram of remaining demand in the second embodiment. [Figure 16] 11 is a flowchart for calculating a start time and an end time of power storage. [Figure 17] FIG. 4 is an explanatory diagram of the time when the reverse flow power is maximum. [Figure 18] 10 is a diagram illustrating an example of a predicted change over time in the amount of stored electricity in a power storage device. FIG. [Figure 19] FIG. 13 is an explanatory diagram of an example of a voltage deviation forecast in the case where a power storage device is present. [Figure 20] 13 is a flowchart of generating a voltage deviation forecast in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] First Embodiment 1 is a schematic block diagram of a power distribution system 300 including a power management device 100 according to an embodiment of the present invention. The power distribution system 300 of this embodiment supplies at least one of power supplied from a power grid and power generated by a solar cell 20 as a distributed power source to an electric device 50 (load) that consumes power. The power distribution system 300 can realize a reverse power flow operation that causes the power generated by the solar cell 20 to flow reversely to the power grid. The power distribution system 300 stops the reverse power flow operation when a voltage deviation state occurs in which the voltage of the power grid becomes equal to or higher than a preset upper limit voltage.

[0018] As shown in FIG. 1, the power distribution system 300 includes a distribution board 10, a solar cell 20 that generates solar power, a power conversion device 30, a power storage device (storage battery) 40 that can store power, an electrical device 50 that functions as a load that consumes power, an information terminal (other device) 60 such as a smartphone carried by a user, and a power management device 100 that controls the power consumption of the electrical device 50.

[0019] The distribution board 10 is supplied with AC power via a power system (not shown). The distribution board 10 is also supplied with AC power obtained by converting DC power generated by the solar cell 20 into AC power by the power converter 30. The distribution board 10 includes a measurement unit 11 that measures the power and voltage supplied from the power system. The measurement unit 11 measures the power generated by the solar cell and the power and voltage of the reverse flow power supplied from the power converter 30 to the distribution board 10. The measurement unit 11 periodically generates measurement data. The measurement unit 11 transmits the generated measurement data to the power management device 100. In FIG. 1, the supply of power is indicated by a dashed line.

[0020] The power conversion device 30 includes a power conversion unit 31 that converts DC power output by the solar cell 20 into AC power, and a power conversion control unit 32 that controls various operations of the power conversion unit 31. The power conversion unit 31 supplies AC power converted from DC power to the power grid via the distribution board 10. The power conversion unit 31 adjusts the frequency and output voltage of the AC power to be output so that the power can be interconnected with the power grid. The converted AC power is also supplied to the electric device 50 from the distribution board 10 via a branch circuit (not shown). Surplus power not consumed by the electric device 50 flows backward through the power grid and is sold.

[0021] The power conversion control unit 32 controls the operation of the power conversion unit 31 to increase or decrease the generated power output by the power conversion unit 31. The power conversion control unit 32 acquires measurement data of the generated power of the solar cell. The power conversion control unit 32 transmits each acquired measurement data to the power management device 100 via the distribution board 10. The power conversion control unit 32 also functions as a communication interface for communicating between the distribution board 10 and the power management device 100. The solar cell 20 and the power conversion device 30 in this embodiment function as a solar power generation device.

[0022] The power management device 100 of this embodiment is a so-called HEMS (Home Energy Management System) that optimally controls home appliances and electrical equipment. The power management device 100 monitors and controls the operating states of the power conversion device 30, the electrical appliances 50, and the information terminal 60 by transmitting and receiving control signals. As shown in Fig. 1, the power management device 100 functions as a data acquisition unit 110, a measurement data storage unit (data storage unit) 120, a weather information storage unit (data storage unit) 130, a reference information storage unit 140, a prediction unit 150, an appliance control unit (output unit) 160 that controls the electrical appliances 50, a voltage deviation forecast creation unit 170, and a recommendation information storage unit 180.

[0023] The data acquiring unit 110 acquires, from the distribution board 10, the measurement data measured by the measuring unit 11 of the distribution board 10 and the measurement data acquired by the power conversion unit 31 of the power conversion device 30. The data acquired by the data acquiring unit 110 includes past data on the system voltage, the power used by the electric device 50, the power generated by the solar cell, and the reverse flow power. The data acquired by the data acquiring unit 110 of this embodiment includes measurement data for at least the most recent seven days. The measurement data acquired by the data acquiring unit 110 is stored in the measurement data storage unit 120.

[0024] The weather information storage unit 130 stores past weather information and weather forecasts (weather forecast information) for at least the next seven days. The weather information in this embodiment is a combination of weather and temperature associated with each day of the week. The weather information storage unit 130 in this embodiment stores past weather information and weather forecasts in advance, but in other embodiments, it may acquire weather information by connecting to the Internet, and may also function as a weather information acquisition unit. The reference information storage unit 140 stores an upper limit voltage of the power grid at which reverse power flow operation is stopped.

[0025] The prediction unit 150 predicts the occurrence of a voltage deviation state for the next seven days using past measurement data stored in the measurement data storage unit 120 and forecast weather information stored in the weather information storage unit 130. As shown in FIG. 1, the prediction unit 150 functions as a demand prediction unit 151 that predicts the power consumption of the electric device 50, a power generation prediction unit 152 that predicts the power generation of the solar cell 20, and a voltage deviation prediction unit 154 that predicts the occurrence of a voltage deviation state. The voltage deviation forecast creation unit 170 creates a voltage deviation forecast based on the above prediction results and data. The voltage deviation forecast is explained below. The prediction method in each prediction unit will be described later.

[0026] The voltage deviation forecast creating unit 170 creates a voltage deviation forecast for the next seven days using the prediction result of the occurrence of a voltage deviation state. The voltage deviation forecast includes information on the purpose of use of electricity acquired by the voltage deviation forecast creating unit 170 through a search, and introduction information including the acquired information on the purpose of use and information on the electric appliances 50 used for the purpose of use. The voltage deviation forecast also includes occurrence information on the predicted occurrence of a voltage deviation state. The voltage deviation forecast creating unit 170 extracts appliances that consume a large amount of electricity (for example, a hot plate, an oven, an induction heating (IH), a dryer, a battery electric vehicle (BEV), an electric drill used for DIY (Do it yourself), etc.). The voltage deviation forecast creating unit 170 acquires information on the purpose of use of electricity using these appliances by searching the Internet.

[0027] The appliance control unit 160 transmits the voltage deviation forecast created by the voltage deviation forecast creating unit 170 to the information terminal 60. The introduction information included in the voltage deviation forecast created by the voltage deviation forecast creating unit 170 is stored in the introduction information storage unit 180.

[0028] The voltage deviation forecast creating unit 170 refers to previously acquired introduction information stored in the introduction information storage unit 180 and searches the Internet to determine whether or not to create information on the newly acquired use purpose. Specifically, if the newly acquired introduction information has the same content as the previously acquired introduction information and if a predetermined period has not passed since the previously acquired introduction information was acquired, the voltage deviation forecast creating unit 170 acquires different introduction information. On the other hand, if the newly acquired introduction information has different content from the previously acquired introduction information or if a predetermined period has passed since the previously acquired introduction information was acquired, the voltage deviation forecast creating unit 170 creates a voltage deviation forecast including the newly acquired introduction information. For example, if the predetermined period is 14 days and a voltage deviation state occurs for two consecutive days, the voltage deviation forecast creating unit 170 does not create a voltage deviation forecast including the use purpose of the same dish using a hot plate, which is the electric appliance 50, for two consecutive days. Alternatively, a voltage deviation forecast is created that provides information on a different dish even if the same hot plate is used.

[0029] In addition, the voltage deviation forecast creation unit 170 creates a voltage deviation forecast that includes additional information including at least one of sale information for products used when using the electrical appliance 50 used to utilize the selected power (e.g., ingredients used when using the cooking utensil) and information on new products for the electrical appliance 50 used to utilize the power.

[0030] The device control unit 160 of this embodiment transmits the power deviation forecast for the next seven days to the information terminal 60 all at once. It transmits once per day. With this configuration, the user can know in advance when and to what extent a voltage deviation will occur, and can plan / prepare for power consumption with ample time. This allows the user to select a power consumption method that requires time for preparation, and allows for effective use of power in a variety of ways. In addition, the power deviation forecast can inform the user of various power consumption methods, which can provide an opportunity for the user to experience something they have never experienced before through effective use of power.

[0031] 2 is a flowchart for creating a voltage deviation forecast. In the flow for creating a voltage deviation forecast, first, the data acquiring unit 110 acquires measurement data of the distribution board 10 and measurement data of the power conversion device 30 (step S21). The measurement data acquired by the data acquiring unit 110 includes the system voltage, the amount of power used by the electric device 50, and the reverse flow power.

[0032] The demand forecasting unit 151 forecasts the demand of the electric device 50 for the next seven days using the measurement data acquired by the data acquiring unit 110 (step S22). The demand forecasting unit 151 forecasts the demand using the amount of purchased power, the amount of power generated by the solar cell 20, and the reverse flow power on the same day of the week one week ago.

[0033] The power generation prediction unit 152 predicts the amount of power generation for the next seven days using the measurement data stored in the measurement data storage unit 120 and the forecast of past weather information stored in the weather information storage unit 130 (step S23). The power generation prediction unit 152 predicts the amount of power generation for the predicted day using the amount of power generation for a past day with the same weather as the predicted weather. If the amount of power generation for a past day used for prediction is suppressed due to the occurrence of a voltage deviation state, the power generation amount prediction flow of FIG. 2 is used to predict the amount of power generation if a voltage deviation state does not occur.

[0034] The voltage deviation prediction unit 154 predicts the occurrence of a voltage deviation state by using the prediction of the amount of power generated by the solar cell 20 and the predicted amount of power demand of the electric device 50 (step S24).

[0035] The voltage deviation forecast creating unit 170 acquires information on the purpose of power use on the scheduled date when a voltage deviation state is to occur by searching the Internet (step S25). The voltage deviation forecast creating unit 170 creates a voltage deviation forecast including the introduced information including the acquired purpose of power use and the occurrence information of the voltage deviation state (step S26), and the voltage deviation forecast creation flow ends. In the process of step S26, as described above, if the newly acquired introduced information including the purpose of power use is the same as the introduced information created in the past, the voltage deviation forecast creating unit 170 judges whether or not a predetermined period has passed and thus determines whether or not a voltage deviation forecast including the newly acquired introduced information should be created. The prediction procedures in the demand prediction unit 151, the power generation prediction unit 152, and the voltage deviation prediction unit 154 will now be described.

[0036] The demand forecasting unit 151 predicts the amount of power demand that will occur as demand for the electric device 50 in the seven days following the day after the day of the electric device 50, using the measurement data stored in the measurement data storage unit 120. Specifically, the demand forecasting unit 151 predicts the amount of power demand for the electric device 50 by solving the following equation (1) using the amount of power purchased from the electric power grid, the amount of power generated by the solar cell 20, and the amount of reverse flow power to the electric power grid on the same day of the week one week ago. Demand power = (purchased power + generated power) - (reverse flow power)…(1)

[0037] The power generation prediction unit 152 predicts the amount of power generation for each predicted day for the next seven days from the next day using the amount of power generation for past days with weather conditions that are the same as the weather predicted for the next seven days from the next day, based on past weather information stored in the weather information storage unit 130. The prediction is carried out in the following steps: (1) Check the weather forecast for the day you want to predict. (2) Read the trends in power generation on days with the same weather conditions over the past week. In this case, if there was a case where power generation was suppressed on a day with the same weather in the past, the amount of power generation that would have been generated if the suppression had not been performed is predicted. The method for predicting the amount of power generation that would have been generated if the suppression had not been performed will be explained later using Figures 3 and 4. (3) The historical power generation trends read in (2) are averaged (for days when suppression occurred, the power generation trends are predicted if suppression had not occurred). (4) The power generation trend averaged in (3) is used as the power generation trend for the forecast day.

[0038] FIG. 3 is an explanatory diagram of a prediction of the amount of power generation. FIG. 3 shows the time transition of the power generated by the solar cell 20. In FIG. 3, the transition of the power generation on a past day when a voltage deviation state occurred is shown by a solid curve C1, and the transition of the power generation on a past day when a voltage deviation state did not occur is shown by a dashed curve C2. In addition, the transition of the power generation in the case where a voltage deviation state did not occur on the past day represented by the curve C1 when the voltage deviation state occurred is shown by a dashed curve C3. Therefore, the suppressed power generation amount P1 on the past day when a voltage deviation state occurred is represented by the area of ​​the hatched region in FIG. 2 obtained by subtracting the curve C2 from the curve C3. The transition of the power generation on a day when a voltage deviation state did not occur may be the average of the power generation transition for the past week.

[0039] -Prediction of power generation (2) Predict the power generation amount if the power generation amount on the day when the voltage deviation occurred is not suppressed- 4 is a flowchart for predicting the amount of power generation when the power generation was not suppressed on a past day when a voltage deviation state occurred. First, the power generation prediction unit 152 acquires the amount of power generation in the past (curve C1) when the weather was the same as that of the predicted day and a voltage deviation state occurred (step S1). The power generation prediction unit 152 uses the amount of power generation in the past to identify times t1 and t2 (FIG. 3) when power generation was suppressed (step S2). The power generation prediction unit 152 identifies times t1 and t2 when the voltage becomes constant from the voltage transition of the solar cell 20.

[0040] The power generation prediction unit 152 obtains the amount of power generation (curve C2) on a day when the weather is the same as that of the past day on which the voltage deviation state occurred and when the voltage deviation state does not occur (step S3). The power generation prediction unit 152 calculates a coefficient so that the power at times t1 and t2 on the curve C2 representing the amount of power generation when the voltage deviation state does not occur is the same as the power on the curve C1 representing the amount of power generation when the voltage deviation state occurs (step S4). In this embodiment, the power generation prediction unit 152 calculates a coefficient so that the sum of the square of the power difference between the curve C1 and the curve C2 at the time t1 and the square of the power difference between the curve C1 and the curve C2 at the time t2 is minimized. The power generation prediction unit 152 predicts a curve obtained by multiplying the calculated coefficient by the curve C2 representing the amount of power generation when the voltage deviation state does not occur as the amount of power generation when the voltage deviation state represented by the curve C3 does not occur (step S5), and the prediction flow of the amount of power generation ends.

[0041] - Voltage deviation prediction - Next, the prediction method of the voltage deviation prediction unit will be described with reference to FIG. The voltage deviation prediction unit 154 shown in FIG. 1 predicts the remaining demand, which is the amount of power obtained by subtracting the predicted amount of power generated by the solar cell 20 from the predicted amount of power demand of the electric device 50 at the time of prediction (step S12). FIG. 6 is an explanatory diagram of the remaining demand. FIG. 6 shows the time transition (curve C4) of the predicted value of the reverse flow power in a state in which the predicted amount of power generated by the solar cell 20 exceeds the amount of power demand of the electric device 50 and power is being sold. The reverse flow power is power supplied from the solar cell 20 to the power grid, and therefore the positive and negative of the remaining demand are reversed. That is, FIG. 6 shows the time transition of the reverse flow power in which the positive and negative of the remaining demand are reversed. As shown in FIG. 6, the curve C4 is highest near noon, which is included in the time t4 to t5, since power is generated by sunlight during the day.

[0042] After the process of step S12 in Fig. 5 is performed, the voltage deviation prediction unit 154 next predicts the upper limit Pmax of the reverse flow power (Fig. 6) (step S13). From past data on the reverse flow power, the upper limit Pmax of the reverse flow power is predicted by different processes for a state in which no voltage deviation state occurs and the reverse flow power is not suppressed, and a state in which a voltage deviation state occurs and the reverse flow power is suppressed.

[0043] 7 is a flowchart for predicting the upper limit Pmax of the reverse flow power when no voltage deviation state occurs. First, the voltage deviation prediction unit 154 acquires measurement data of the reverse flow power and voltage when no voltage deviation state occurs in the past (step S131A). The voltage deviation prediction unit 154 extracts a correlation function Fa between the reverse flow power and the voltage from the acquired measurement data (step S132A).

[0044] Fig. 8 is an explanatory diagram of the correlation function Fa between the reverse flow power and voltage when no voltage deviation state occurs. Fig. 8 shows the correlation function Fa when the horizontal axis represents the reverse flow power and the vertical axis represents the voltage. DT1 to DT5 shown in Fig. 8 are plots of past data. The voltage deviation prediction unit 154 of this embodiment extracts the correlation function Fa by applying the least squares method to the multiple plots DT1 to DT5.

[0045] The upper limit Pmax of the reverse flow power is calculated using the extracted correlation function Fa and the upper limit voltage at which power is suppressed that is stored in the reference information storage unit 140 (step S133A in FIG. 7). As shown in FIG. 8, on the correlation function Fa, the power value corresponding to the upper limit voltage is calculated as the upper limit Pmax of the reverse flow power, and the prediction flow for the upper limit Pmax of the reverse flow power ends.

[0046] FIG. 9 is a flowchart for predicting the upper limit Pmax of reverse power flow in a state where a voltage deviation state has occurred. First, data on reverse power flow and voltage in past voltage deviation states are acquired (step S131B). When a voltage deviation state has occurred, the maximum value of the voltage among the acquired measurement data is acquired (step S132B). From the acquired measurement data, measurement data of voltage values equal to or greater than the value obtained by multiplying the maximum voltage by a predetermined multiplier k (for example, 0.995) are extracted (step S133B). The predetermined multiplier k may be set by the user or may be stored in the reference information storage unit 140.

[0047] FIG. 10 is an explanatory diagram showing the correlation between data on reverse power flow and voltage in a state where a voltage deviation state has occurred. In FIG. 8, nine data DT6 to DT14 are plotted when the reverse power flow is taken on the horizontal axis and the voltage is taken on the vertical axis. In FIG. 8, in addition to data DT6 to DT14, among data DT6 to DT14, the voltage value of data DT11, which is the maximum value of the voltage, and the value obtained by multiplying the maximum voltage value of data DT11 by a multiplier k (for example, 0.995, 0 < k < 1) are shown by a broken line.

[0048] When the process of step S133B in FIG. 9 is performed, the power storage amount prediction unit 153 extracts, as the upper limit Pmax of the reverse power flow, the reverse power flow corresponding to the voltage value of data DT10, which is the minimum value, from among data DT10 to DT14 (FIG. 10) that are equal to or greater than the value obtained by multiplying the extracted maximum voltage by the multiplier k (step S134B), and ends the prediction flow of the upper limit Pmax of the reverse power flow.

[0049] The voltage deviation prediction unit 154 calculates the suppressed power, which is the suppressed power generation power of the solar cell 20, using the predicted upper limit Pmax of the reverse power flow (step S14 in FIG. 5). As shown in FIG. 6, the suppressed power amount P3 is calculated by using the predicted upper limit Pmax of the reverse power flow and the time transition of the reverse power flow (curve C4).

[0050] As described above, in the power management device 100 of the present embodiment, the data acquisition unit 110 acquires the measurement data measured by the measurement unit 11 of the distribution board 10 and the measurement data acquired by the power conversion unit 31 of the power conversion device 30. The weather information storage unit 130 stores past weather information and forecasts of weather information for at least the next seven days. The prediction unit 150 predicts the occurrence of a voltage deviation state for the next seven days using the past measurement data stored in the measurement data storage unit 120 and the forecast of weather information stored in the weather information storage unit 130. The voltage deviation forecast creation unit 170 creates a voltage deviation forecast for the next seven days using the prediction result of the occurrence of the voltage deviation state. The voltage deviation forecast includes information on the use of the power acquired by the search by the voltage deviation forecast creation unit 170, and introduction information including the acquired information on the use and information on the electrical appliance 50 used for the use. The voltage deviation forecast also includes occurrence information on the occurrence of the predicted voltage deviation state. In this embodiment, the occurrence of a voltage deviation state at least on the next day and thereafter is predicted. The voltage deviation forecast to be created includes the recommendation information acquired by the search and the occurrence information of the voltage deviation state. Therefore, the power that is scheduled to be suppressed among the power generated by the solar cell 20 due to the occurrence of the voltage deviation state can be used for the use of the power output in advance by the prediction. In other words, the user can effectively utilize the power that was scheduled to be suppressed on the next day and thereafter by referring to the recommendation information.

[0051] Furthermore, in the present embodiment, when the newly acquired introduction information has the same content as the previously acquired introduction information and when a predetermined period has not elapsed since the previously acquired introduction information was acquired, the voltage deviation forecast creating unit 170 acquires different introduction information. On the other hand, when the newly acquired introduction information has different content from the previously acquired introduction information or when a predetermined period has elapsed since the previously acquired introduction information was acquired, the voltage deviation forecast creating unit 170 creates a voltage deviation forecast including the newly acquired introduction information. That is, when a predetermined period has not elapsed, introduction information with the same content is not output to the information terminal 60. On the other hand, even if the acquired introduction information has the same content as the past, when a predetermined period has elapsed or the content of the acquired introduction information is different from the past, it is output to the information terminal 60 as novel introduction information. As a result, it is not necessary to propose the same introduction information to the user who is the owner of the information terminal 60 until a predetermined period has elapsed, which not only promotes effective use of surplus power but also provides the user with an opportunity to experience something new through the use of surplus power.

[0052] In addition, the voltage deviation forecast creating unit 170 of this embodiment extracts, from among the electric appliances 50 that can be controlled by the appliance control unit 160, for example, a hot plate, an oven, an IH, a dryer, a BEV, and an electric drill used for DIY, and transmits the extracted information to the information terminal 60 via the appliance control unit 160. In this embodiment, the power usage applications such as cooking, laundry, use of an electric vehicle, and DIY consume relatively large amounts of power, but require time for preparation. Therefore, by using the present technology to prepare in advance, it becomes possible to effectively use power for the above applications.

[0053] Furthermore, the voltage deviation forecast creating unit 170 of this embodiment transmits additional information including at least one of sale information of products used when using the electric appliance 50 used to utilize the selected power and information on new models of the electric appliance 50 used to utilize the power to the information terminal 60 via the appliance control unit 160. In this embodiment, a voltage deviation forecast is created that includes additional information such as sale information and information on new models of appliances used as a load in addition to the use of the power. Therefore, by obtaining the voltage deviation forecast via the information terminal 60, for example, if the use of the power is cooking, the user can prepare ingredients for cooking or replace old cooking utensils that they already own with new ones at a lower cost.

[0054] Furthermore, the voltage deviation forecast creating unit 170 of this embodiment transmits to the information terminal 60, at once, the power deviation forecasts corresponding to the respective scheduled occurrence dates of the voltage deviation state among the following seven days. In this embodiment, the voltage deviation forecasts and the power usage for the following seven days are transmitted to the information terminal 60. Many users have a life rhythm in which one week is a cycle of seven days. Therefore, by transmitting the voltage deviation forecasts including the power usage for the following seven days to the information terminal 60 in advance, the user can make a schedule for the week in accordance with the life rhythm. As a result, the user can make more effective use of the power that was scheduled to be suppressed on the scheduled occurrence date.

[0055] <First Example> An example of a specific method of utilizing the power included in the voltage deviation forecast will be described below. In this embodiment, when the voltage deviation forecast creating unit 170 selects "cooking" as the category of the power usage purpose, it acquires recommendation information included in the voltage deviation forecast transmitted to the appliance control unit 160. The recommendation information includes information regarding the electric appliance 50 controlled by the appliance control unit 160 when using power and the method of using the electric appliance 50.

[0056] 11 is a flowchart for generating a voltage deviation forecast in the first embodiment. In the flow for generating a voltage deviation forecast, first, a scheduled occurrence date on which a voltage deviation state will occur within the next seven days from the next day is identified (step S31). For example, the current date is May 22, and 2 kWh of power is scheduled to be suppressed on May 25, three days later.

[0057] Next, the voltage deviation forecast creating unit 170 identifies the season of the suppression date from the scheduled occurrence date (step S32). The voltage deviation forecast creating unit 170 identifies the electric appliance 50 as a cooking appliance that can be controlled by the appliance control unit 160 (step S33). The voltage deviation forecast creating unit 170 searches for dishes on the Web or in a social networking service (SNS) using the identified season and the electric appliance 50 (e.g., a hot plate used for "cooking") as search words (step S34). Note that a specific search word such as "Instagrammable" may be added during the search.

[0058] The voltage deviation forecast creating unit 170 provisionally determines a plurality of dishes from the search results, taking into consideration the number of accesses (step S35). The voltage deviation forecast creating unit 170 further acquires additional information related to the provisionally determined dishes. Examples of the additional information include sale information for ingredients used in the recipe of the dish, information on drinks that go well with the dish, flyers for nearby supermarkets identified from the sale information and date, and sale information for electrical appliances 50 used in the cooking.

[0059] The voltage deviation forecast creating unit 170 determines whether the same recipe as the provisionally determined recipe has been previously introduced (step S36) by referring to the past recommendation information stored in the recommendation information storage unit 180. If it is determined that the same recipe as the provisionally determined recipe has not been previously introduced (step S36: NO), the process proceeds to step S38, which will be described later.

[0060] If it is determined that the provisionally determined cooking method has been introduced in the past (step S36: YES), the voltage deviation forecast creating unit 170 determines whether a predetermined period (e.g., 14 days) has passed since the provisionally determined cooking method was introduced in the past (step S37). If the predetermined period has not passed since the provisionally determined cooking method was introduced (step S37: NO), a cooking method is provisionally determined again (step S35).

[0061] If it is determined that a predetermined period of time has passed since the provisionally determined recipe was introduced (step S37: NO), the voltage deviation forecast creating unit 170 creates a voltage deviation forecast including the introduction information of the provisionally determined recipe (step S38), and the voltage deviation forecast creation flow ends. The introduction information acquired by the search is stored in the introduction information storage unit 180. The introduction information may include additional information acquired in the process of step S35. In the process of step S37, the provisional decision process may not be performed again if at least one recipe is introduced. The created voltage deviation forecast is shown in FIG. 12. The weather for the next seven days, the possibility of voltage deviation, and the predicted suppressed power amount are described. In addition, sale information and information on the use of power (URL of the site to be introduced and a representative diagram, etc.) are also described at the same time. Information on the guideline value of the power consumed in the introduced use of power may also be written. The reference value of the power consumption may be obtained by using a search result on the Internet or the like, or information on representative electrical devices may be researched in advance and stored in the reference information storage unit 140. In this way, by receiving a voltage deviation forecast, the user can obtain information on when and how much power will be suppressed, and on methods for making effective use of that power. As a result, the user can carry out power usage purposes that require time for preparation with plenty of time to do so. Voltage deviation forecasts are sent out once a day, and new power usage applications are sent out every day. This allows users to know a variety of power usage applications before a voltage deviation occurs, and to select their preferred applications from among them.

[0062] As described above, when "cooking" is selected as the use of electricity as in the first embodiment, information on the electric appliances 50 to be used is transmitted to the information terminal 60 in advance, so that the user can purchase ingredients to be used in cooking and prepare them in advance. In addition, since recommendation information created in the past before the predetermined period has passed is not transmitted to the information terminal 60, the user can learn new uses of electricity (how to make another dish). In addition, since dishes are searched for on the Web or SNS, there is a possibility that dishes that the user would not have thought of as uses of electricity will be presented. This not only enables the effective use of electricity, but also increases the possibility that the user will gain serenity (unexpected happiness). As a result, the user's effective use of electricity is further promoted. In addition, since sale information on ingredients to be used in cooking and sale information on the electric appliances 50 to be used in cooking are transmitted to the information terminal 60, the user can reduce food expenses while making effective use of electricity.

[0063] <Second embodiment> As in the second embodiment, the power management device 100a may be used in a state in which it includes a power storage device 40. The operation when it includes not only a solar cell but also a storage battery will be described below. An example configuration is shown in FIG. 13. The second embodiment differs from the first embodiment (FIG. 1) in that it includes a power storage device 40, and that the voltage deviation prediction unit 154a of the prediction unit 150 predicts the amount of power stored in the power storage device 40. Note that in the second embodiment, configurations and controls that differ from those in the first embodiment will be described, and descriptions of configurations and controls that are the same as those in the first embodiment will be omitted.

[0064] -Demand forecast- The demand forecasting unit 151 predicts the amount of power demand that will occur as demand for the electric device 50 in the seven days following the day after the day of the electric device 50, using the measurement data stored in the measurement data storage unit 120. Specifically, the demand forecasting unit 151 predicts the amount of power demand for the electric device 50 by solving the following equation (2) using the amount of power purchased from the electric power grid, the amount of power generated by the solar cell 20, the amount of reverse flow power to the electric power grid, and the amount of power charged and discharged by the power storage device 40, on the same day of the week one week ago. Demand power = (purchased power + generated power + discharged power) - (reverse flow power + charging power)…(2)

[0065] -Explanation of battery capacity forecast- The voltage deviation prediction unit 154a shown in FIG. 13 predicts the storage battery capacity, which is the capacity that the power storage device 40 can store, on each of the prediction days for the next seven days and thereafter, using the power generation amount predicted by the power generation prediction unit 152 and the power demand amount predicted by the demand prediction unit 151. In this embodiment, the voltage deviation prediction unit 154a predicts the storage battery capacity on the unknown prediction day using the known storage battery capacity of the power storage device 40 on today. Specifically, the voltage deviation prediction unit 154a predicts the storage battery capacity on the prediction day in sequence using two times, the sunrise time and the sunset time, at which the reverse power flow power becomes zero in one day. For example, the voltage deviation prediction unit 154a predicts the storage battery capacity at the unknown sunrise time of the next day using the storage battery capacity at the known sunset time of the current day. In addition, the voltage deviation prediction unit 154a predicts the storage battery capacity at the sunset time of the next day using the storage battery capacity at the predicted sunrise time of the next day. In this manner, the voltage deviation prediction unit 154a successively predicts the storage battery capacity for the next seven days.

[0066] 14 is a flowchart for predicting the storage battery capacity. The voltage deviation prediction unit 154a first acquires the storage battery capacity at a time when the reverse flow power is zero (step S11a). The voltage deviation prediction unit 154a acquires the storage battery capacity at a time (sunset of the current day) immediately before the storage battery capacity at the predicted time (for example, sunrise of the next day). If the storage battery capacity at the time immediately before the predicted time is known, the voltage deviation prediction unit 154a acquires the storage battery capacity from the measurement data storage unit 120. On the other hand, if the storage battery capacity at the time immediately before the predicted time is unknown, the voltage deviation prediction unit 154a acquires the storage battery capacity at the time immediately before the predicted time predicted by successive predictions.

[0067] The voltage deviation prediction unit 154a shown in FIG. 13 predicts the remaining demand, which is the amount of power obtained by subtracting the predicted amount of power generation by the solar cell 20 from the predicted amount of power demand by the electric device 50 at the time of prediction (step S12a). FIG. 15 is an explanatory diagram of the remaining demand in the second embodiment. FIG. 15 shows the time transition (curve C4) of the predicted value of the reverse flow power in a state in which the predicted amount of power generation by the solar cell 20 exceeds the amount of power demand by the electric device 50 and power is being sold. The reverse flow power is power supplied from the solar cell 20 to the power grid, and therefore the positive and negative of the remaining demand are reversed. That is, FIG. 15 shows the time transition of the reverse flow power in which the positive and negative of the remaining demand are reversed. As shown in FIG. 1, the curve C4 is highest near noon, which is included in the time t4 to t5, since power is generated by sunlight during the day.

[0068] When the remaining demand is predicted, the voltage deviation prediction unit 154a predicts the discharge power amount of the power storage device 40 using the remaining demand (step S13a in FIG. 14). In this embodiment, the voltage deviation prediction unit 154a calculates the discharge power amount P2 of the power storage device 40 from the sunset time t6 of the day to the sunrise time t3 of the next day using the sunset time t6 (FIG. 15) at which the reverse flow power becomes zero and the sunrise time t3. As shown in FIG. 1, the times t3 and t6 are times at which the reverse flow power is zero, that is, the power consumption of the electric device 50 and the power generation power of the solar cell 20 are the same. From the time t6 onwards until the time t3 of the next day, the power consumption of the electric device 50 is covered by the discharge of the power storage device 40. Therefore, the voltage deviation prediction unit 154a can calculate the discharge power amount P2 by using the predicted remaining demand of the electric device 50, the sunset time t6, and the sunrise time t3. Time t4 is the start time of power storage in the power storage device 40. Time t5 is the end time of power storage in the power storage device 40. Prediction of times t4 and t5 will be described later.

[0069] The voltage deviation prediction unit 154a predicts the available capacity CS of the power storage device 40 at the unknown sunrise time t3 of the next day, using the predicted discharge power amount P2 and the storage amount of the power storage device 40 at the known sunset time t6 (step S14a in FIG. 14). The voltage deviation prediction unit 154a predicts the amount of power stored at time t3 of the next day by subtracting the predicted discharge power amount P2 (FIG. 15) from the storage amount at the known time t6. The voltage deviation prediction unit 154a predicts the available capacity CS by using the predicted storage amount and the capacity that the solar cell 20 can store.

[0070] The voltage deviation prediction unit 154a calculates the start time t4 and end time t5 of the storage of power by the power storage device 40 after time t3 on the day after the predicted amount of stored power (step S15a). When the free capacity CS of the power storage device 40 is insufficient and part of the power generated by the solar cell 20 cannot be stored in the power storage device 40, it is necessary to suppress part of the power generation. The greater the reverse flow power is during the period, the higher the possibility of suppressing the power generation. Therefore, by charging the power storage device 40 during the period when the reverse flow power is large, the possibility of avoiding suppression of the power generation is increased. Therefore, in this embodiment, the start time t4 and end time t5 of power storage are calculated so that the power storage device 40 is charged during the period when the reverse flow power is high.

[0071] FIG. 16 is a flowchart for calculating the start time t4 and end time t5 of power storage. The voltage deviation prediction unit 154a first extracts the time t7 at which the reverse flow power is maximum by using the time transition of the predicted reverse flow power (step S151). FIG. 17 is an explanatory diagram of the time t7 at which the reverse flow power is maximum. FIG. 17 shows the time t7 at which the curve C4 representing the time transition of the reverse flow power shown in FIG. 15 is maximum. The voltage deviation prediction unit 154a provisionally determines the start time t4 and end time t5 such that the amount of stored power of the power storage device 40, which is the time integral of the curve C4, becomes equal to the free capacity CS of the power storage device 40 (step S152 in FIG. 16). In this embodiment, the start time t4 and end time t5 are provisionally determined such that the time from the start time t4 to the time t7 is equal to the time from the time t7 to the end time t5.

[0072] The voltage deviation prediction unit 154a calculates the amount of stored power from the start time t4 to the end time t5 using the provisionally determined start time t4 and end time t5 and a curve C4 that represents the time transition of the reverse flow power (step S153). The voltage deviation prediction unit 154a determines whether the calculated amount of stored power is less than the available capacity of the power storage device 40 at time t3 when the remaining demand is zero (step S154). If it is determined that the amount of generated power is equal to or greater than the available capacity at time t3 (step S154: NO), the process of step S156 described below is performed.

[0073] If it is determined in the process of step S154 that the amount of generated power is less than the available capacity at time t3 (step S154: YES), the voltage deviation prediction unit 154a determines whether the start time t4 and the end time t5 are the same as the times t3 and t6 at which the reverse flow power is zero (step S155). If it is determined that the times t3 and t4 are the same and the times t5 and t6 are different (step S155: NO), the processes from step S152 onwards are performed again. If it is determined that the combination of the two times is the same (step S155: YES), the voltage deviation prediction unit 154a determines the provisionally determined start time t4 and end time t5 as the official times, and ends the calculation flow of the start time and end time.

[0074] FIG. 18 is an explanatory diagram of an example of a time transition of the predicted storage amount AC of the power storage device 40. As shown in FIG. 18, after sunset time t6 when the reverse flow power becomes negative in FIG. 15, the storage amount AC starts to decrease due to discharging. From sunrise time t3 when the reverse flow power changes from negative to positive to storage start time t4, the storage amount AC does not change. From start time t4 to end time t5, the power storage device 40 starts storing power, so the storage amount AC starts to increase. End time t5 is the time when the free capacity CS (FIG. 15) is set to zero, that is, the storage amount AC is set to be maximum (MAX in FIG. 18). Therefore, the storage amount AC of the power storage device 40 at end time t5 is maximum.

[0075] When the process of step S15a in Fig. 14 is performed, the voltage deviation prediction unit 154a predicts the upper limit Pmax of the reverse flow power (Fig. 15) (step S16a). The voltage deviation prediction unit 154a predicts the upper limit Pmax of the reverse flow power by different processes based on past reverse flow power data for a state in which no voltage deviation state occurs and the reverse flow power is not suppressed, and a state in which a voltage deviation state occurs and the reverse flow power is suppressed. The prediction procedure is similar to that of the configuration without a storage battery in the first embodiment, and therefore a description thereof will be omitted.

[0076] 14, the voltage deviation prediction unit 154a uses the upper limit Pmax of the predicted reverse flow power to calculate the suppressed power that is suppressed from the power generated by the solar cell 20 (step S17a). As shown in FIG 15, the voltage deviation prediction unit 154a calculates the suppressed power amount P3 by using the upper limit Pmax of the predicted reverse flow power, the time transition of the reverse flow power (curve C4), and the available capacity CS of the power storage device 40.

[0077] The voltage deviation prediction unit 154a predicts the storage battery capacity of the power storage device 40 at sunset time t6 of the next day using the calculated suppressed power amount P3 (step S18a in FIG. 14), and the flow of predicting the storage battery capacity ends. As described above, the voltage deviation prediction unit 154a predicts the storage battery capacity at sunrise time t3 of the next day from the storage battery capacity at sunset time t6 of the current day, which is known. Furthermore, the voltage deviation prediction unit 154a predicts the storage battery capacity at sunset time t6 of the next day using the predicted storage battery capacity at time t3. In this way, the voltage deviation prediction unit 154a sequentially predicts the storage battery capacity of the power storage device 40 from the next day onwards from the known storage battery capacity.

[0078] The voltage deviation forecast creating unit 170 creates a voltage deviation forecast for the next seven days using the predicted result of the occurrence of a voltage deviation state. The method of creating the forecast is the same as that of the configuration without a storage battery. An example of a created voltage deviation forecast is shown in FIG. 19. The information on the power usage purpose is an example of a search for "cooking" in the genre "hot plate". It is assumed that the forecast was sent in the morning of 5 / 20 (7:00 a.m., etc.). From the voltage deviation forecast shown in FIG. 19, it can be seen that suppression may occur for two days, three days and four days later. The amount of suppressed power is 2 kWh each, and the amount of stored power on the suppression day is 4 kWh. From this, it can be seen that the user can avoid suppression by consuming 2 kWh of power by the day before. In addition, it can be seen that the amount of stored power as of 8:00 a.m. on that day is 4 kWh, and there is 4 kWh of unused power in the battery. It can be seen that suppression can be avoided by using 2 kWh of this. Therefore, it is assumed that the user plans to cook with a hot plate on the night of 5 / 22. In this case, the ingredients need to be prepared by May 22. In a configuration without the power storage device 40, it was necessary to consume power at the timing of the voltage deviation, but in the power management device 100a of the second embodiment with the power storage device 40, the timing of power consumption can be set to the night before, making it possible to consume power in accordance with the user's lifestyle.

[0079] <Second Example> In the second embodiment, when the voltage deviation forecast creating unit 170 selects "laundry" as an electric power usage purpose, it acquires recommended information corresponding to "laundry." Fig. 20 is a flowchart of creating a voltage deviation forecast in the second embodiment. First, the voltage deviation forecast creating unit 170 identifies the scheduled occurrence date on which voltage deviation information is to occur (step S41).

[0080] The voltage deviation forecast creating unit 170 judges whether the season of the specified scheduled occurrence date is near May, June, September, or October, when people change clothes (step S42). If it is judged that the season of the scheduled occurrence date is near the season when people change clothes (step S42: YES), the voltage deviation forecast creating unit 170 searches for information related to changing clothes included in the category "laundry" (step S43). In the season of changing clothes, not only clothes but also sheets, duvet covers, down jackets, etc. may be washed. Therefore, there is a possibility that the laundry space (e.g., a place to dry clothes) is insufficient compared to usual. In this case, it is considered that there is a demand for using a dryer or drying clothes indoors using an air conditioner. In addition to the information on the usage of these electric appliances 50, the voltage deviation forecast creating unit 170 may search for sale information on products used when using the electric appliances 50, such as laundry products suitable for drying clothes indoors, storage products for clothes, and products used for washing (e.g., detergent).

[0081] In the process of step S42, if it is determined that the season of the scheduled occurrence date is not near the season for changing clothes (step S42: NO), the voltage deviation forecast creating unit 170 searches for information related to laundry other than changing clothes (step S44). Information related to laundry other than changing clothes includes, for example, information about washing cushions, carpets, stuffed toys, etc., in addition to washing regular clothes. The voltage deviation forecast creating unit 170 may search for and acquire washing methods for items that are not usually washed, such as cushions and stuffed toys.

[0082] The voltage deviation forecast creating unit 170 provisionally determines the laundry information to be transmitted to the information terminal 60 (step S45). The voltage deviation forecast creating unit 170 judges whether the same content as the provisionally determined laundry information has been introduced in the past (step S46). If it is judged that the same content as the provisionally determined laundry information has not been introduced in the past (step S46: NO), the process of step S48 described later is performed.

[0083] If it is determined that the same content as the provisionally determined laundry information has been introduced in the past (step S46: YES), the voltage deviation forecast creating unit 170 determines whether a predetermined period of time has passed since the information was previously introduced (step S47). If the predetermined period of time has not passed since the same content as the provisionally determined laundry information was introduced (step S47: NO), the laundry information is provisionally determined again (step S45).

[0084] If it is determined that a predetermined period of time has passed since the same content as the provisionally determined washing information was introduced (step S47: NO), the voltage deviation forecast creating unit 170 creates a voltage deviation forecast including the provisionally determined washing information and the introduced information included in the voltage deviation forecast (step S48), and the voltage deviation forecast creating flow of the second embodiment ends. The introduced information acquired by the search is stored in the introduced information storage unit 180.

[0085] As described above, when "laundry" is selected as the method of utilizing power as in the second embodiment, power can be effectively utilized during the season when people change clothes. Here, the season when people change clothes is a time when pollen, PM (Particulate Matter) 2.5, yellow sand, etc. are dispersed in large amounts, and therefore, the need to dry laundry indoors increases. Furthermore, this season is a time when the amount of power generated by the solar cell 20 is large, and a voltage deviation state occurs and power is likely to be suppressed. Therefore, by notifying the user of the forecast of the generation suppression day during these seasons, the user can satisfy the demand for laundry while effectively utilizing the power that was scheduled to be suppressed. In addition, the user can reduce the cost of laundry by using the power that was scheduled to be suppressed to dry laundry at home. In addition, by notifying the user of sale information such as laundry products suitable for indoor drying, clothing storage products, and products used for laundry as additional information, the user can utilize power more effectively.

[0086] Furthermore, the prediction unit 150a may use data on the amount of pollen in the air in addition to the weather information forecast. In this case, the voltage deviation forecast creating unit 170 may acquire recommendation information by selecting "cooking" as the use of electricity on a day with a large amount of pollen in the air, and may acquire recommendation information by selecting "laundry" as the use of electricity on a day with a small amount of pollen in the air.

[0087] <Modifications of the embodiment> The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit of the present invention, for example, the following modifications are possible: In the above-described embodiment, a part of the configuration realized by hardware may be replaced by software, and conversely, a part of the configuration realized by software may be replaced by hardware.

[0088] The power management device 100 of the power distribution system 300 described in the above embodiment, first example, and second example is merely an example and can be modified. The power management device 100 can be modified to the extent that it includes a measurement data storage unit 120 that acquires measurement data via the distribution board 10, a weather information storage unit 130 that functions as a weather information acquisition unit, and a voltage deviation forecast creation unit 170 that acquires the power usage purpose and creates a voltage deviation forecast. For example, the power management device 100 does not include the introduction information storage unit 180, and does not need to refer to whether the introduction information included in the voltage deviation forecast acquired by the voltage deviation forecast creation unit 170 has the same content as introduction information created in the past.

[0089] In the above embodiment, the scheduled occurrence dates on which the voltage deviation state will occur for the next 7 days from the next day onwards are predicted, but the power management apparatus 100 may predict at least the scheduled occurrence dates from the next day onwards. For example, only the next day may be predicted, or the five days from 3 days to 7 days from now may be predicted. The device control unit 160 transmits the voltage deviation forecasts for the scheduled occurrence dates for the next 7 days from the next day onwards to the information terminal 60 at once, and then transmits the voltage deviation forecasts only for the scheduled occurrence dates at 7 a.m. on each of the scheduled occurrence dates, but the method of transmitting the voltage deviation forecasts can be modified. For example, the voltage deviation forecast for the scheduled occurrence date may be transmitted only on the scheduled occurrence date, or the transmission time may be set by the user. Note that the time at which the voltage deviation forecast is transmitted on the scheduled occurrence date is preferably before sunrise t3 ( FIG. 15 ) at which the reverse power flow current begins to be generated.

[0090] The device control unit 160 may acquire information on the voltage of the power grid from the data acquisition unit 110 via the prediction unit 150 in real time. In this case, when a voltage deviation state occurs, the device control unit 160 may start charging the power storage device 40 even at a time different from the time when the voltage deviation state predicted in advance occurs. When the voltage deviation occurs even after the charging of the power storage device 40 starts, the device control unit 160 may suppress the power generation of the solar cell 20 so that the voltage is equal to or lower than the upper limit voltage. In addition, the electric device 50 that may be automatically driven when a voltage deviation state occurs may be registered in advance by a user's setting.

[0091] The power source functioning as the distributed power source may be other than the solar cell 20. The distributed power source may be a power source using wind power, a power source using geothermal power, or a power source using hydropower.

[0092] The power generation prediction unit 152 predicted the amount of power generation in the case where a voltage deviation state did not occur on a day on which a voltage deviation state had occurred in the past by multiplying the amount of power generation on a day on which no voltage deviation state occurred by a coefficient as shown in Fig. 2, but the prediction method can be modified. For example, when the hours of sunlight vary, the amount of power generation may be predicted by multiplying the time axis by a coefficient.

[0093] In the above first and second embodiments, the recommended information when "cooking" and "laundry" are selected as the genres has been described as an example, but the selected genre can be changed. For example, when the user's holiday is scheduled to occur, the user may be notified of recommended information in the genre of "driving" using a BEV. In this case, the voltage deviation forecast may include information on popular spots for driving.

[0094] Although the present aspect has been described above based on the embodiment and modified examples, the above-mentioned embodiment of the aspect is intended to facilitate understanding of the present aspect and does not limit the present aspect. The present aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents are included in the present aspect. Furthermore, if a technical feature is not described as essential in this specification, it may be deleted as appropriate.

[0095] The present invention can also be realized in the following forms. [Application example 1] A power management device used in a power distribution system that supplies at least one of power supplied from a power grid and power generated by a distributed power source to a load that consumes power, and when a voltage deviation state occurs in which a voltage of the power grid becomes equal to or higher than a preset upper limit voltage, stops a reverse power flow of the power generated by the distributed power source to the power grid, a data acquisition unit that acquires data including a voltage change in the power grid, power generated by the distributed power source, reverse flow power that flows reversely from the distributed power source to the power grid, and power usage by the load; A weather information acquisition unit that acquires weather forecast information for at least the next day and thereafter; a data storage unit that stores the data acquired by the data acquisition unit and the weather forecast information acquired by the weather information acquisition unit; a prediction unit that predicts the power generated by the distributed power source, the reverse flow power, the power usage of the load, and the occurrence of the voltage deviation state at least from the next day onward, using the data stored in the data storage unit and the weather forecast information; a voltage deviation forecast creating unit that, when the prediction unit predicts the occurrence of the voltage deviation state on the next day or later, acquires by search information on an intended use of electricity on a scheduled occurrence date on which the voltage deviation state is to occur, and creates a voltage deviation forecast that includes introduction information including the acquired information on the intended use and information on the load used for the intended use, and information on the predicted occurrence of the voltage deviation state; an output unit that outputs the voltage deviation forecast created by the voltage deviation forecast creating unit to another device; A power management device comprising: [Application example 2] The power management device according to the first aspect, The data acquisition unit further acquires data including charging power when a storage battery capable of storing power is charged, discharging power discharged from the storage battery, and a storage amount of the storage battery; The prediction unit predicts a change in the amount of stored power in the storage battery for at least the next day. [Application example 3] The power management device according to the first or second aspect of the present invention further comprises: an introduction information storage unit that stores the introduction information acquired by the voltage deviation forecast creation unit; The voltage deviation forecast creating unit, By referring to the introduction information stored in the introduction information storage unit, if the newly acquired introduction information has the same content as the previously acquired introduction information and a predetermined period has not elapsed since the previously acquired introduction information was acquired, acquire different introduction information; The power management device refers to the introduction information stored in the introduction information storage unit, and creates the voltage deviation forecast including the newly acquired introduction information if the newly acquired introduction information has different content from the previously acquired introduction information, or if the specified period has passed since the previously acquired introduction information was acquired. [Application example 4] The power management device according to any one of application examples 1 to 3, The power management device, wherein the information on the intended use included in the introduction information is information related to any one of cooking, laundry, use of an electric vehicle, and DIY (Do it yourself). [Application example 5] The power management device according to any one of application examples 1 to 4, The voltage deviation forecast creating unit, Obtaining additional information by searching, the additional information being at least one of sale information for a product used when the load is used and information for a new product of the electrical equipment that is the load; The power management apparatus further generates the voltage deviation forecast including the additional information. [Application Example 6] The power management device according to any one of application examples 1 to 5, The prediction unit predicts a transition in the amount of stored power in the storage battery and a transition in the occurrence of the voltage deviation state for each of the seven days from the next day onwards, the voltage deviation forecast creating unit creates the voltage deviation forecast corresponding to each of the expected occurrence dates when the occurrence of the voltage deviation state is predicted for at least one day out of seven days after the day following the predicted date; The output unit outputs the created voltage deviation forecasts for one or more days to another device all at once. [Application Example 7] A computer program used in a power distribution system that supplies at least one of power supplied from a power grid and power generated by a distributed power source to a load that consumes power, and when a voltage deviation state occurs in which a voltage of the power grid becomes equal to or higher than a preset upper limit voltage, stops a reverse flow of the power generated by the distributed power source to the power grid, a data acquisition function that acquires data including a voltage change in the power grid, power generated by the distributed power source, reverse flow power that flows reversely from the distributed power source to the power grid, and power usage by the load; A weather information acquisition function that acquires weather forecast information for at least the next day and thereafter; a data storage function for storing the data acquired by the data acquisition function and the acquired weather forecast information; a prediction function that predicts the power generated by the distributed power source, the reverse flow power, the power usage of the load, and the occurrence of the voltage deviation state at least for the next day and thereafter, using the data stored in the data storage function and the weather forecast information; a voltage deviation forecast creation function for, when the occurrence of the voltage deviation state is predicted for the next day or later, acquiring by search information on the purpose of use of electricity on the scheduled occurrence date of the voltage deviation state, and creating a voltage deviation forecast including introduction information including the acquired information on the purpose of use and information on the load used for the purpose of use, and information on the predicted occurrence of the voltage deviation state; an output function of outputting the generated voltage deviation forecast to another device; A computer program that enables a computer to realize the above. [Explanation of symbols]

[0096] 10…Distribution board 11…Measuring section 20…Solar cells (distributed power supply) 30...Power conversion device 31...Power conversion section 32...Power conversion control unit 40...Electricity storage device (storage battery) 50...Electrical equipment (load) 60...Information terminal (other device) 100,100a…Power management device 110…Data acquisition section 120...Measurement data storage unit (data storage unit) 130...weather information storage unit (data storage unit, weather information acquisition unit) 140...Reference information storage unit 150, 150a…Prediction section 151…Demand Forecasting Department 152…Power Generation Forecasting Department 154, 154a...Voltage deviation prediction unit 160...Device control unit (output unit) 170…Voltage deviation forecast creation section 180...Introduction information storage unit 300,300a…Distribution system AC…Storage amount CS: Free capacity of the storage device DT1~DT5, DT6~DT14...Data Fa…Correlation function P1…Amount of generated power P2…discharge power amount P3…Suppression power amount Pmax: Upper limit of reverse power flow t1~t7…Time

Claims

1. A power management device used in a power distribution system that supplies at least one of power supplied from a power grid and power generated by a distributed power source to a load that consumes power, and when a voltage deviation state occurs in which a voltage of the power grid becomes equal to or higher than a preset upper limit voltage, stops a reverse power flow of the power generated by the distributed power source to the power grid, a data acquisition unit that acquires data including a voltage change in the power grid, power generated by the distributed power source, reverse flow power that flows reversely from the distributed power source to the power grid, and power usage by the load; A weather information acquisition unit that acquires weather forecast information for at least the next day and thereafter; a data storage unit that stores the data acquired by the data acquisition unit and the weather forecast information acquired by the weather information acquisition unit; a prediction unit that predicts the power generated by the distributed power source, the reverse flow power, the power usage of the load, and the occurrence of the voltage deviation state at least from the next day onward, using the data stored in the data storage unit and the weather forecast information; a voltage deviation forecast creating unit that, when the prediction unit predicts the occurrence of the voltage deviation state on the next day or later, acquires by search information on an intended use of electricity on a scheduled occurrence date on which the voltage deviation state is to occur, and creates a voltage deviation forecast that includes introduction information including the acquired information on the intended use and information on the load used for the intended use, and information on the predicted occurrence of the voltage deviation state; an output unit that outputs the voltage deviation forecast created by the voltage deviation forecast creating unit to another device; A power management device comprising:

2. 2. The power management device of claim 1, The data acquisition unit further acquires data including charging power when a storage battery capable of storing power is charged, discharging power discharged from the storage battery, and a storage amount of the storage battery; The prediction unit predicts a change in the amount of stored power in the storage battery for at least the next day.

3. The power management device of claim 2, further comprising: an introduction information storage unit that stores the introduction information acquired by the voltage deviation forecast creation unit; The voltage deviation forecast creating unit, By referring to the introduction information stored in the introduction information storage unit, if the newly acquired introduction information has the same content as the previously acquired introduction information and a predetermined period has not elapsed since the previously acquired introduction information was acquired, acquire different introduction information; The power management device refers to the introduction information stored in the introduction information storage unit, and creates the voltage deviation forecast including the newly acquired introduction information if the newly acquired introduction information has different content from the previously acquired introduction information, or if the specified period has passed since the previously acquired introduction information was acquired.

4. 4. The power management device of claim 3, The power management device, wherein the information on the intended use included in the introduction information is information related to any one of cooking, laundry, use of an electric vehicle, and DIY (Do it yourself).

5. 5. The power management device of claim 4, The voltage deviation forecast creating unit, Acquire additional information by searching, the additional information being at least one of sale information for a product used when the load is used and information for a new product of the electrical equipment that is the load; The power management apparatus further generates the voltage deviation forecast including the additional information.

6. A power management device according to any one of claims 2 to 5, The prediction unit predicts a transition in the amount of stored power in the storage battery and a transition in the occurrence of the voltage deviation state for each of seven days from the next day onwards, the voltage deviation forecast creating unit creates the voltage deviation forecast corresponding to each of the expected occurrence dates when the occurrence of the voltage deviation state is predicted for at least one day out of seven days from the day after the predicted occurrence date; The output unit outputs the created voltage deviation forecasts for one or more days at once to another device.

7. A computer program used in a power distribution system that supplies at least one of power supplied from a power grid and power generated by a distributed power source to a load that consumes power, and when a voltage deviation state occurs in which a voltage of the power grid becomes equal to or higher than a preset upper limit voltage, stops a reverse flow of the power generated by the distributed power source to the power grid, a data acquisition function that acquires data including a voltage change in the power grid, power generated by the distributed power source, reverse flow power that flows reversely from the distributed power source to the power grid, and power usage by the load; A weather information acquisition function that acquires weather forecast information for at least the next day and thereafter; a data storage function for storing the data acquired by the data acquisition function and the acquired weather forecast information; a prediction function that predicts the power generated by the distributed power source, the reverse flow power, the power usage of the load, and the occurrence of the voltage deviation state at least for the next day and thereafter, using the data stored in the data storage function and the weather forecast information; a voltage deviation forecast creation function for, when the occurrence of the voltage deviation state is predicted for the next day or later, acquiring by search information on the purpose of use of electricity on the scheduled occurrence date of the voltage deviation state, and creating a voltage deviation forecast including introduction information including the acquired information on the purpose of use and information on the load used for the purpose of use, and information on the predicted occurrence of the voltage deviation state; an output function of outputting the generated voltage deviation forecast to another device; A computer program that enables a computer to realize the above.

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