Charging / discharging control system

Abstract

To provide a charging / discharging control system capable of easily increasing a profit from selling electricity.SOLUTION: A charging / discharging control system 100 for creating a charging / discharging plan for a storage battery 31 capable of charging / discharging power generated by a photovoltaic power generation unit 21 comprises: an information acquisition unit 110 and a control unit 120 that acquire a predicted power generation amount, which is a predicted value of a power generation amount for each unit time by the photovoltaic power generation unit 21, and a predicted power demand amount, which is a predicted value of a power demand amount for each unit time (steps S11 and S12) ; and a control unit 120 (plan creation unit) that on the basis of the predicted power generation amount and the predicted power demand amount acquired by the information acquisition unit 110 and the control unit 120, creates a charging / discharging plan (steps S13 to S16).SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to the technology of a charge-discharge control system for controlling the charge and discharge of a storage battery.

Background Art

[0002] Conventionally, the technology of a charge-discharge control system for controlling the charge and discharge of a storage battery has been known. For example, it is as described in Patent Document 1.

[0003] Patent Document 1 discloses a system for creating a charge-discharge plan for a storage battery based on the predicted power generation value of a renewable energy power source and the predicted value of the electricity market unit price. In the system described in Patent Document 1, by controlling the charge and discharge of the storage battery according to the charge-discharge plan created in this way, an increase (maximization) in the power sales revenue is achieved.

[0004] However, the predicted value of the electricity market unit price may not be easily obtainable, and a system that can easily increase the power sales revenue is desired.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention has been made in view of the above circumstances, and the problem to be solved is to provide a charge-discharge control system that can easily increase the power sales revenue.

Means for Solving the Problems

[0007] The problem to be solved by the present invention is as described above. Next, the means for solving this problem will be described.

[0008] That is, in claim 1, it is a charge / discharge plan control system that creates a charge / discharge plan for a rechargeable battery with the electric power generated by a power generation unit capable of generating power using natural energy. The system includes an acquisition unit that acquires a predicted power generation amount, which is a predicted value of the power generation amount per unit time by the power generation unit, and a predicted power demand amount, which is a predicted value of the power demand amount per unit time, and a plan creation unit that creates the charge / discharge plan based on the predicted power generation amount and the predicted power demand amount acquired by the acquisition unit.

[0009] In claim 2, when it is predicted that the predicted power generation amount is less than the chargeable amount of the storage battery, the plan creation unit creates the charge / discharge plan so as to charge all of the predicted power generation amount to the storage battery.

[0010] In claim 3, when it is predicted that the predicted power generation amount is equal to or more than the chargeable amount of the storage battery, the plan creation unit allocates the time for charging the storage battery in order from the time zone with the largest predicted power generation amount.

[0011] In claim 4, the plan creation unit allocates the time for discharging the storage battery in order from the time zone with the largest predicted power demand amount.

[0012] In claim 5, the plan creation unit ranks the predicted power demand amounts for each unit time in descending order, and creates the charge / discharge plan so as to discharge the storage battery in the time zone where the average rank of the ranks of consecutive unit times is the highest.

[0013] In claim 6, it includes a control unit that controls the charge / discharge of the storage battery based on the charge / discharge plan created by the plan creation unit. When the actual power generation amount, which is the actual power generation amount by the power generation unit, is less than the planned power sales amount, which is the power sales amount in the charge / discharge plan, the control unit discharges the storage battery by the difference between the planned power sales amount and the actual power generation amount.

[0014] In claim 7, when the actual power storage amount of the storage battery becomes equal to or less than a predetermined value, the control unit stops discharging from the storage battery.

[0015] In claim 8, when the actual power generation amount is equal to or more than the planned power selling amount, the control unit charges the storage battery by the difference between the actual power generation amount and the planned power selling amount.

Advantages of the Invention

[0016] As an effect of the present invention, the following effects are achieved.

[0017] In claim 1, it is possible to easily increase the power selling profit.

[0018] In claim 2, it is possible to increase the power selling amount at the planned discharge time.

[0019] In claim 3, it is possible to effectively increase the power selling profit.

[0020] In claim 4, it is possible to effectively increase the power selling profit.

[0021] In claim 5, it is possible to effectively increase the power selling profit.

[0022] In claim 6, it is possible to eliminate the imbalance.

[0023] In claim 7, it is possible to reduce the imbalance while ensuring the power selling amount at the planned discharge time.

[0024] In claim 8, it is possible to ensure the power selling amount at the planned discharge time.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0026] Hereinafter, the charge-discharge control system 100 according to an embodiment of the present invention will be described.

[0027] The charge-discharge control system 100 according to an embodiment of the present invention creates a charge-discharge plan (hereinafter referred to as "charge-discharge plan") for the storage battery 31 of the power selling system 1 shown in FIG. 1, and controls the charge-discharge of the storage battery 31 based on the created charge-discharge plan. Note that the charge-discharge plan includes the planned value of the power that is reverse-fed directly to the grid power source S (without passing through the storage battery 31) among the power generated by the solar power generation unit 21 described later. Hereinafter, first, the configuration of the power selling system 1 will be described with reference to FIG. 1.

[0028] The power selling system 1 shown in FIG. 1 generates power using sunlight and sells the generated power. In the present embodiment, the power selling system 1 is one in which a storage station is co-located with a solar power plant. The user of the power selling system 1 and the charge-discharge control system 100 is, for example, a power generation company. The power selling system 1 mainly includes a power generation system 20, a power storage system 30, and a control device 40.

[0029] The power generation system 20 is capable of generating power using sunlight. The power generation system 20 includes a solar power generation unit 21 and a power conditioner 22.

[0030] The solar power generation unit 21 is a device that generates electricity using sunlight. The solar power generation unit 21 is composed of a solar cell panel or the like. The solar power generation unit 21 is installed in a sunny place such as on the roof of a building. The solar power generation unit 21 is connected to a power conditioner 22 described later.

[0031] The power conditioner 22 is a power conditioner that can appropriately convert power. The power conditioner 22 is connected to the solar power generation unit 21 as described above.

[0032] The power storage system 30 can charge and discharge electricity. The power storage system 30 includes a storage battery 31 and a power conditioner 32.

[0033] The storage battery 31 can charge and discharge electricity. The storage battery 31 is composed of, for example, a lithium-ion battery or the like. The storage battery 31 is connected to a power conditioner 32 described later.

[0034] The power conditioner 32 is a power conditioner that can appropriately convert power. The power conditioner 32 is connected to the storage battery 31 as described above. Also, the power conditioner 32 is arranged closer to the grid power source S than the power conditioner 22.

[0035] In the power selling system 1 configured as described above, the electricity generated by the solar power generation unit 21 can be directly sold by flowing back in the reverse direction to the grid power source S. Also, a part of the electricity generated by the solar power generation unit 21 can be charged to the storage battery 31, and the remaining electricity can be sold by flowing back in the reverse direction to the grid power source S. Also, the power selling system 1 can sell the electricity discharged from the storage battery 31 by flowing back in the reverse direction to the grid power source S. Also, the power selling system 1 can purchase electricity from the grid power source S and charge the storage battery 31. The transaction of buying and selling electricity is carried out in the wholesale electricity market.

[0036] The main wholesale electricity market is the day-ahead market (spot market). The day-ahead market is a market where electricity transactions are conducted on the day before the bid target day (the day of actual supply and demand). In the day-ahead market, transactions are carried out for 48 products (48 segments) obtained by dividing a day into 30-minute units.

[0037] A charge / discharge control system 100 is connected to a power conditioner 32 of a power storage system 30. The charge / discharge control system 100 can control a storage battery 31 via the power conditioner 32. More specifically, the charge / discharge control system 100 creates a charge / discharge plan in advance and controls the charge and discharge of the storage battery 31 via the power conditioner 32 based on the created charge / discharge plan. The charge / discharge control system 100 includes an information acquisition unit 110 and a control unit 120.

[0038] The information acquisition unit 110 acquires various types of information. The information acquisition unit 110 can acquire information for predicting the power generation amount by the solar power generation unit 21 and information for predicting the power demand via a network such as the Internet.

[0039] The control unit 120 creates a charge / discharge plan for the storage battery 31 and controls the charge and discharge of the storage battery 31 based on the created charge / discharge plan. The control unit 120 can predict the power generation amount by the solar power generation unit 21 and the power demand in the entire power supply area based on the information acquired by the information acquisition unit 110. Further, the control unit 120 can create a charge / discharge plan for the storage battery 31 based on the predicted values of the power generation amount by the solar power generation unit 21 and the power demand in the entire power supply area. Then, the control unit 120 can control the charge and discharge of the storage battery 31 based on the created charge / discharge plan.

[0040] The control unit 120 creates a charge / discharge plan for the storage battery 31 by executing the plan creation control shown in FIG. 3. Hereinafter, the method for creating the charge / discharge plan will be described using the flowchart shown in FIG. 3. Note that the bidding in the wholesale power market (one-day-ahead market) is performed based on the charge / discharge plan created by executing the plan creation control shown in FIG. 3. Since the bidding in the one-day-ahead market needs to be performed by 10:00 am, the plan creation control shown in FIG. 3 is performed by 10:00 am on the day of the bidding in the one-day-ahead market.

[0041] Note that, hereinafter, the day on which the bidding in the day-ahead market is conducted may be simply referred to as the "current day", and the day of physical supply and demand (i.e., the day after the day on which the bidding in the day-ahead market is conducted) may be simply referred to as the "next day".

[0042] In step S11, the control unit 120 predicts the power generation amount for each unit time of the next day. Here, the "solar power generation amount" means the power generation amount by the solar power generation unit 21 (the total power generation amount by all the solar power generation units 21 of the power selling system 1). The unit time is, for example, 30 minutes (one frame). The control unit 120 predicts the solar power generation amount for every 30 minutes of the next day based on the weather forecast of the next day and the data of the past solar power generation amount obtained through the information acquisition unit 110. Thus, the control unit 120 obtains the predicted value of the solar power generation amount for every 30 minutes of the next day (hereinafter referred to as the "predicted power generation amount").

[0043] After performing the process of step S11, the control unit 120 proceeds to step S12.

[0044] In step S12, the control unit 120 predicts the area power demand for each unit time (30 minutes) of the next day. Here, the "area power demand" means the power demand in the entire power supply area of the power company to which the user (power generation business operator) sells electricity. The control unit 120 predicts the area power demand for every 30 minutes of the next day based on the weather forecast of the next day and the data of the past area power demand obtained through the information acquisition unit 110. Thus, the control unit 120 obtains the predicted value of the area power demand for every 30 minutes of the next day (hereinafter sometimes simply referred to as the "area power demand").

[0045] After performing the process of step S12, the control unit 120 proceeds to step S13.

[0046] In step S13, the control unit 120 determines whether the predicted daily power generation amount is greater than the storable amount (predicted daily power generation amount > storable amount). Here, the "predicted daily power generation amount" means the predicted daily power generation amount of the solar power generation unit 21. Also, the "storable amount" means the amount of power that can be stored in the storage battery 31. The storable amount is set to a value smaller than the battery capacity (the capacity of the storage battery 31) (battery capacity × α) in order to suppress overcharging and overdischarging of the storage battery 31 and for the adjustment cost of imbalance. Here, α is a coefficient smaller than 1. However, when the actual solar power generation amount (hereinafter referred to as "actual power generation amount") on the next day is smaller than the predicted power generation amount due to the uncertainty of the prediction of the solar power generation amount, the coefficient α is set to a value as close to 1 as possible as long as overcharging, overdischarging, or imbalance of the storage battery 31 does not occur. The coefficient α is set to, for example, 0.8.

[0047] When the control unit 120 determines that the predicted daily power generation amount > storable amount (in step S13, "YES"), it proceeds to step S14. On the other hand, when the control unit 120 determines that the predicted daily power generation amount > storable amount is not satisfied (in step S13, "NO"), it proceeds to step S15.

[0048] In step S14, the control unit 120 makes a charging plan for the storage battery 31 in order from the time zone with a large solar power generation amount (predicted power generation amount). Specifically, the control unit 120 assigns to the time for charging the storage battery 31 (charging plan time) in order from the frames with a large predicted power generation amount among each frame (48 frames per day) divided in 30 - minute units. The charging amount to the storage battery 31 is set to the storable amount (battery capacity × α) used in step S13. Also, the control unit 120 creates a charge - discharge plan so that the surplus of the predicted power generation amount over the storable amount is fed back to the grid - connected power source S for power selling.

[0049] On the other hand, in step S15, the control unit 120 creates a charge - discharge plan so that the entire amount of the solar power generation is charged to the storage battery 31. That is, the control unit 120 assigns all the time zones in which the solar power generation unit 21 can generate power to the charging plan time, and sets the power selling amount at the charging plan time to 0.

[0050] After performing the process of step S14 or step S15, the control unit 120 proceeds to step S16.

[0051] In step S16, the control unit 120 determines the discharge time based on the power demand prediction rank. Here, the "power demand prediction rank" is a rank assigned to each frame such that the higher the area power demand, the higher the rank.

[0052] Specifically, the control unit 120 ranks the frames in descending order of the area power demand acquired in step S12 within a predetermined time period (for example, from 18:00 to 24:00) that is after the charging planned time and is generally considered to have a high selling electricity unit price, and creates the power demand prediction rank. More specifically, the control unit 120 ranks the frame with the highest area power demand within the predetermined time period (from 18:00 to 24:00) as rank 1, the next frame with the highest area power demand as rank 2, and the next frame with the highest area power demand as rank 3, and so on. Then, the control unit 120 assigns the frames with a higher power demand prediction rank (smaller power demand prediction rank number) to the time (discharge planned time) for discharging from the storage battery 31.

[0053] The number of frames of the discharge planned time (discharge frame number) is determined by (charging planned amount / discharge capacity). Here, the "charging planned amount" means the planned value of the charging amount to the storage battery 31 and is set to the same value as the storable amount in step S13. Also, the "discharge capacity" means the maximum amount of electric power that the storage battery 31 can discharge in one frame.

[0054] Here, from the viewpoint of operation efficiency, it is desirable for the storage battery 31 to discharge continuously rather than in small increments. Therefore, the control unit 120 sets a time period (frames for the number of consecutive discharge frames) with a small average value of the power demand prediction rank as the discharge planned time.

[0055] FIG. 4 shows an example of the area power demand, the power demand prediction rank, and the average rank for each frame (30 minutes) from 18:00 to 24:00. In the example shown in FIG. 4, the number of discharge frames is 4 frames. Also, the average rank in the table shown in FIG. 4 indicates the average value of the power demand prediction ranks from the time zone of the column of the average rank to 4 frames later. For example, the average rank of the frame at 18:00 (the time zone from 18:00 to 18:30) indicates the average value of the power demand prediction ranks from the frame at 18:00 to the frame at 19:30 (the time zone from 19:30 to 20:00) (4 frames).

[0056] In the example shown in FIG. 4, the average rank at 18:30 (the average value of the power demand prediction ranks from the frame at 18:30 to the frame at 20:00) is 2.5, which is the smallest. Therefore, the control unit 120 sets 18:30, which is the first time of the frame at 18:30 with the highest average rank (the smallest average value of the power demand prediction ranks), as the discharge start time, and sets the number of discharge frames after the discharge start time (from the frame at 18:30 to the frame at 20:00) as the discharge planned time. Note that the discharge planned time may be simply assigned in order from the time zone with a large area power demand.

[0057] After performing the process of step S16, the control unit 120 ends the planning control shown in FIG. 3. The charge / discharge plan created by the planning control shown in FIG. 3 can be reflected in the bidding in the power market.

[0058] In this way, by creating a charge / discharge plan for the storage battery 31 so that charging of the storage battery 31 is performed in a time zone with a large amount of solar power generation where the power market unit price is generally low, and discharging from the storage battery 31 is performed in a time zone with a large area power demand where the power market unit price is generally high, the selling electricity profit can be increased. Also, since the charge / discharge plan for the storage battery 31 can be created without using the predicted value of the power market unit price, it is possible to easily increase the selling electricity profit.

[0059] Based on the charge-discharge plan created in this way, the control device 40 actually (in real time) controls the charge and discharge of the storage battery 31. However, there may be a deviation between the actual power generation amount (actual solar power generation amount) of the solar power generation unit 21 and the predicted power generation amount of the solar power generation unit 21 obtained in step S11, which may cause an imbalance. Therefore, in order to suppress the imbalance, the control unit 120 performs the charge-discharge control shown in FIGS. 5 and 6. Hereinafter, the charge-discharge control shown in FIGS. 5 and 6 will be described. The charge-discharge control shown in FIGS. 5 and 6 is repeatedly executed at a predetermined interval on the day after the bidding target day (the day of actual supply and demand).

[0060] In step S21, the control unit 120 determines whether the current time has not yet reached 18:00 (the current time is ~18:00).

[0061] If the control unit 120 determines that the current time is ~18:00 (\"YES\" in step S21), it proceeds to step S22. On the other hand, if the control unit 120 determines that the current time is not ~18:00 (\"NO\" in step S21), it proceeds to step S31 in FIG. 6.

[0062] In step S22, the control unit 120 determines whether the planned power sales amount is greater than the actual power generation amount (planned power sales amount > actual power generation amount). Here, the \"planned power sales amount\" means the power sales amount (planned value of power sales amount) in the created charge-discharge plan, which is determined in step S14 of FIG. 3. The actual power generation amount is the cumulative value for 30 minutes in the previous frame of the current frame, and the planned power sales amount is the planned power sales amount in the previous frame of the current frame. Also, the actual power generation amount may be the cumulative value in the current frame. In this case, the planned power sales amount is the expected value of the planned power sales amount at the current time. For example, if the current time is 16:15 and the planned power sales amount in the 16:00 frame is 2 [MWh], then 2 [MWh] × (15 / 30) = 1 [MWh].[[]END]]

[0063] When the control unit 120 determines that the planned electricity sales volume > the actual power generation volume ( "YES" in step S22), it proceeds to step S23. On the other hand, when the control unit 120 determines that the planned electricity sales volume > the actual power generation volume is not true ( "NO" in step S22), it proceeds to step S26.

[0064] Note that when the planned electricity sales volume > the actual power generation volume (YES in step S22), it means that the actual solar power generation volume is insufficient with respect to the planned electricity sales volume, and there is a possibility of imbalance occurring.

[0065] In step S23, the control unit 120 determines whether the current time has not yet reached 15:00 (the current time is ~15:00).

[0066] When the control unit 120 determines that the current time is ~15:00 ( "YES" in step S23), it proceeds to step S25. On the other hand, when the control unit 120 determines that the current time is not ~15:00 ( "NO" in step S23), it proceeds to step S24.

[0067] In step S24, the control unit 120 determines whether the SOC is greater than the planned SOC (SOC > planned SOC). Here, "SOC" means the actual (current) power storage amount of the storage battery 31. Also, "planned SOC" means the power storage amount of the storage battery 31 in the charge / discharge plan (the planned value of the power storage amount of the storage battery 31).

[0068] When the control unit 120 determines that SOC > planned SOC ( "YES" in step S24), it proceeds to step S25. On the other hand, when the control unit 120 determines that SOC > planned SOC is not true ( "NO" in step S24), it ends the charge / discharge control shown in FIGS. 5 and 6.

[0069] Note that the case where SOC > planned SOC (YES in step S24) means that the actual power storage level of the storage battery 31 is more than the planned value, and there is a margin in the power storage level of the storage battery 31 (even if discharged, the planned power sales volume at night can be ensured). On the other hand, the case where SOC > planned SOC is not satisfied (NO in step S24) means that the actual power storage level of the storage battery 31 is less than or equal to the planned value, and there is no margin in the power storage level of the storage battery 31 (if discharged, the planned power sales volume at night cannot be ensured).

[0070] In step S25, the control unit 120 discharges the difference between the planned power sales volume and the actual power generation volume (planned power sales volume - actual power generation volume) from the storage battery 31.

[0071] When the actual solar power generation volume is insufficient with respect to the planned power sales volume in this way (YES in step S22), the control unit 120 can eliminate the imbalance by discharging the difference between the planned power sales volume and the actual power generation volume from the storage battery 31 until 15:00. Also, even after 15:00, the control unit 120 discharges the difference between the planned power sales volume and the actual power generation volume from the storage battery 31 to eliminate the imbalance, but when the power storage level of the storage battery 31 becomes less than the planned value, the discharge from the storage battery 31 is stopped. In this way, by changing the method of discharging from the storage battery 31 according to the time (before 15:00 and after 15:00), it is possible to reduce the imbalance while ensuring the power sales volume during the planned discharge time (night).

[0072] On the other hand, in step S26, the control unit 120 determines whether the current time is the planned charging time. As described above, the "planned charging time" means the time zone in which discharge from the storage battery 31 is planned in the charge-discharge plan, and is the time zone determined in step S14 of FIG. 3 (the time zone with a large solar power generation volume).

[0073] When the control unit 120 determines that the current time is the planned charging time ( "YES" in step S26), it proceeds to step S30. On the other hand, when the control unit 120 determines that the current time is not the planned charging time ( "NO" in step S26), it proceeds to step S27.

[0074] In step S27, the control unit 120 determines whether the current time has not yet reached 15:00 (the current time is ~15:00).

[0075] If the control unit 120 determines that the current time is ~15:00 (in step S27, "YES"), it proceeds to step S28. On the other hand, if the control unit 120 determines that the current time is not ~15:00 (in step S27, "NO"), it proceeds to step S29.

[0076] In step S28, the control unit 120 determines whether the SOC is less than "planned SOC + 10%" (SOC < planned SOC + 10%).

[0077] If the control unit 120 determines that SOC < planned SOC + 10% (in step S28, "YES"), it proceeds to step S30. On the other hand, if the control unit 120 determines that SOC < planned SOC + 10% is not true (in step S28, "NO"), it ends the charge-discharge control shown in FIG. 5. Note that "+10%" is set with a margin so that the stored power of the storage battery 31 does not fall short of the planned power sales volume during the planned discharge time (nighttime).

[0078] On the other hand, in step S29, the control unit 120 determines whether the SOC is less than the planned SOC (SOC < planned SOC).

[0079] If the control unit 120 determines that SOC < planned SOC (in step S29, "YES"), it proceeds to step S30. On the other hand, if the control unit 120 determines that SOC < planned SOC is not true (in step S29, "NO"), it ends the charge-discharge control shown in FIGS. 5 and 6.

[0080] In step S30, the control unit 120 charges the storage battery 31 with the difference between the actual power generation amount and the planned power sales volume (actual power generation amount - planned power sales volume).

[0081] When the actual solar power generation amount is not insufficient compared to the planned power sales amount in this way (NO in step S22), the control unit 120 charges the difference between the actual power generation amount and the planned power sales amount to the storage battery 31 in preparation for night-time power sales at the charging planned time. On the other hand, the control unit 120 charges the storage battery 31 up to the planned SOC + 10% outside the charging planned time. Also, the control unit 120 charges the storage battery 31 up to the planned SOC after 15:00. By performing charging to the storage battery 31 in this way, the power sales amount during the discharge planned time (night-time) can be ensured.

[0082] Next, the control of the storage battery 31 after 18:00 (NO in step S21) will be described. After 18:00, the control unit 120 controls the charge and discharge of the storage battery 31 according to the charge and discharge plan created by the plan creation control in FIG. 3.

[0083] In step S31 shown in FIG. 6, the control unit 120 determines whether the planned SOC is greater than the SOC (planned SOC > SOC).

[0084] When the control unit 120 determines that the planned SOC > SOC (YES in step S31), it proceeds to step S32. On the other hand, when the control unit 120 determines that the planned SOC > SOC is not satisfied (NO in step S31), it proceeds to step S33.

[0085] Note that when the planned SOC > SOC (YES in step S31), it means that the actual stored power amount of the storage battery 31 is less than the planned value, and the stored power amount of the storage battery 31 is insufficient for the planned power sales amount during the discharge planned time. On the other hand, when the planned SOC > SOC is not satisfied (NO in step S31), it means that the actual stored power amount of the storage battery 31 is equal to or more than the planned value, and the stored power amount of the storage battery 31 is not insufficient for the planned power sales amount during the discharge planned time (the planned power sales amount can be ensured).

[0086] In step S32, the control unit 120 modifies the discharge plan. Specifically, the control unit 120 reduces the planned power sales amount at the discharge plan time to the actual power storage amount of the storage battery 31. The commands for reducing the planned power sales amount are selected in the order of the lowest (largest number) power demand prediction rank among the discharge plan times. For example, when the number of discharge commands is 4 (the discharge plan time is 2 hours), the planned power sales amount of the command with the 4th power demand prediction rank (the command at 18:30 in the example of FIG. 4) is reduced until the actual power storage amount of the storage battery 31 becomes the same as the planned value. However, if the planned SOC > SOC even when the planned power sales amount of the command with the 4th power demand prediction rank is set to 0, then the planned power sales amount of the command with the next lowest power demand prediction rank, which is the 3rd power demand prediction rank (the command at 20:00 in the example of FIG. 4), is reduced until the actual power storage amount of the storage battery 31 becomes the same as the planned value. By reducing the planned power sales amount from the commands with lower power demand prediction ranks in this way, the planned power sales amount is reduced to the actual power storage amount of the storage battery 31. Note that it is preferable that the commands for reducing the planned power sales amount are selected so that the discharge plan time does not become fragmented (discontinuous). For example, if the discharge plan time becomes fragmented when reducing the planned power sales amount of the command with the Xth power demand prediction rank, the planned power sales amount of the command with the next lowest power demand prediction rank, which is the (X - 1)th power demand prediction rank, may be reduced instead.

[0087] After performing the process of step S32, the control unit 120 proceeds to step S33.

[0088] In step S33, the control unit 120 discharges from the storage battery 31 according to the discharge plan. Specifically, the control unit 120 discharges from the storage battery 31 by the amount of the planned power sales amount at the discharge plan time (step S16 in FIG. 3) according to the charge / discharge plan created by the plan creation control shown in FIG. 3 or the charge / discharge plan modified in step S32.

[0089] Thus, at the planned discharge time, the control unit 120 performs discharge from the storage battery 31 according to the charge-discharge plan (discharge plan). However, when the stored power of the storage battery 31 is insufficient for the planned power sales volume, the planned power sales volume is decreased to the actual stored power of the storage battery 31, and the time period for discharging from the storage battery 31 is set to a time period with a low power demand prediction rank. Thereby, power sales revenue can be secured.

[0090] As described above, the charge-discharge control system 100 according to the present embodiment is a charge-discharge control system 100 that creates a charge-discharge plan for a storage battery 31 capable of charging and discharging the electric power generated by a solar power generation unit 21 (a power generation unit capable of generating power using natural energy), an information acquisition unit 110 and a control unit 120 (acquisition unit) that acquire a predicted power generation amount that is a predicted value of the power generation amount per unit time by the solar power generation unit 21 and a predicted power demand amount that is a predicted value of the power demand amount per unit time (steps S11 and S12), and a control unit 120 (plan creation unit) that creates the charge-discharge plan based on the predicted power generation amount and the predicted power demand amount acquired by the information acquisition unit 110 and the control unit 120 (steps S13 to S16). It is provided with.

[0091] With such a configuration, it is possible to easily increase the power sales revenue. Specifically, by creating a charge-discharge plan for the storage battery 31 so that charging of the storage battery 31 is performed in a time period with a large solar power generation amount and discharging from the storage battery 31 is performed in a time period with a large area power demand amount, the power sales revenue can be increased. In addition, since the charge-discharge plan for the storage battery 31 can be created without using the predicted value of the power market unit price, it is possible to easily increase the power sales revenue.

[0092] Further, the control unit 120 (plan creation unit) When it is predicted that the predicted power generation amount is less than the chargeable amount of the storage battery 31 (NO in step S13), the charge-discharge plan is created so as to charge all of the predicted power generation amount to the storage battery 31 (step S15).

[0093] With such a configuration, it is possible to increase the amount of power sold during the discharge plan time (nighttime).

[0094] Further, the control unit 120 (plan creation unit) When it is predicted that the predicted power generation amount is equal to or more than the chargeable amount of the storage battery 31 (YES in step S13), it is allocated to the time for charging the storage battery 31 in order from the time zone with the largest predicted power generation amount (step S14).

[0095] With such a configuration, it is possible to effectively increase the power sales revenue.

[0096] Further, the control unit 120 (plan creation unit) Allocate the time for discharging the storage battery 31 to the time zone with the largest predicted power demand amount (step S16).

[0097] With such a configuration, it is possible to effectively increase the power sales revenue.

[0098] Further, the control unit 120 (plan creation unit) Rank in descending order of the predicted power demand amount for each unit time, and create the charge-discharge plan so as to discharge from the storage battery in the time zone where the average rank of the ranks of the continuous unit times is the highest (step S16).

[0099] With such a configuration, it is possible to effectively increase the power sales revenue.

[0100] Further, it includes a control unit 120 (control unit) that controls the charge and discharge of the storage battery 31 based on the charge-discharge plan created by the control unit 120 (plan creation unit). The control unit 120 (control unit) when the actual power generation amount (actual power generation amount) by the solar power generation unit 21 is less than the planned power sales amount (planned power sales amount) in the charge / discharge plan (YES in step S22 of FIG. 5), discharges from the storage battery by the difference between the planned power sales amount and the actual power generation amount (step S25).

[0101] With such a configuration, imbalance can be eliminated.

[0102] Also, the control unit 120 (control unit) when the actual stored power amount (SOC) of the storage battery 31 becomes equal to or less than a predetermined value (planned SOC) (NO in step S24), stops discharging from the storage battery 31.

[0103] With such a configuration, it is possible to reduce imbalance while ensuring the power sales amount during the discharge planned time (night time).

[0104] Also, the control unit 120 (control unit) when the actual power generation amount is equal to or greater than the planned power sales amount (NO in step S22), charges the storage battery 31 by the difference between the actual power generation amount and the planned power sales amount (step S30).

[0105] With such a configuration, it is possible to ensure the power sales amount during the discharge planned time (night time).

[0106] As described above, the embodiments of the present invention have been described, but the present invention is not limited to the above configuration, and various modifications are possible within the scope of the invention described in the claims.

[0107] For example, in the present embodiment, the control device 40 is configured to be provided outside the power storage system 30, but it may be configured to be provided inside the power storage system 30, such as being incorporated inside the storage battery 31, and its configuration is not limited.

[0108] In addition, in this embodiment, the charge / discharge control system 100 is configured to be provided outside the control device 40, but it may also be configured to be provided inside the control device 40, and its configuration is not limited.

[0109] In addition, in this embodiment, the power generation unit is configured to include the photovoltaic power generation unit 21. However, instead of the photovoltaic power generation unit 21, it may have other power supply sources (for example, a hydroelectric power generation unit or a wind power generation unit that generates electricity using natural energy other than sunlight).

[0110] In addition, in this embodiment, the discharge planned time is set between 18:00 and 24:00. However, the discharge planned time may be set from a wider range of time periods. For example, the discharge planned time may be set between 8:00 and 6:00 the next day.

[0111] In addition, in this embodiment, the discharge planned time is set for continuous time periods (frames), but it may also be set for discontinuous time periods (frames).

[0112] In addition, in this embodiment, in the real-time control of the storage battery 31, the way of discharging from the storage battery 31 is changed according to time (before 15:00 and after 15:00). However, the way of discharging from the storage battery 31 may be the same before 15:00 and after 15:00.

Explanation of Reference Numerals

[0113] 21 Photovoltaic power generation unit 31 Storage battery 100 Charge / discharge control system 110 Information acquisition unit 120 Control unit

Claims

1. A charge / discharge control system that creates a charge / discharge plan for a rechargeable battery using the electric power generated by a power generation unit capable of generating power using natural energy, an acquisition unit that acquires a predicted power generation amount, which is a predicted value of the power generation amount per unit time by the power generation unit, and a predicted power demand amount, which is a predicted value of the power demand amount per unit time; a plan creation unit that creates the charge / discharge plan based on the predicted power generation amount and the predicted power demand amount acquired by the acquisition unit; comprising: a charge / discharge control system.

2. The plan creation unit creates the charge / discharge plan so as to charge all of the predicted power generation amount to the storage battery when it is predicted that the predicted power generation amount is less than the chargeable amount of the storage battery. The charge / discharge control system according to claim 1.

3. The plan creation unit allocates, in order from the time zone with the largest predicted power generation amount, the time for charging the storage battery when it is predicted that the predicted power generation amount is equal to or greater than the chargeable amount of the storage battery. The charge / discharge control system according to claim 1 or claim 2.

4. The plan creation unit allocates, in order from the time zone with the largest predicted power demand amount, the time for discharging the storage battery. The charge / discharge control system according to claim 1 or claim 2.

5. The plan creation unit ranks the predicted power demand amounts for each unit time in descending order, and creates the charge / discharge plan so as to discharge the storage battery in the time zone with the highest average rank of consecutive unit times. The charge / discharge control system according to claim 1 or claim 2.

6. comprises a control unit that controls the charge / discharge of the storage battery based on the charge / discharge plan created by the plan creation unit, wherein the control unit discharges the storage battery by the difference between the planned power sales amount and the actual power generation amount when the actual power generation amount, which is the actual power generation amount by the power generation unit, is less than the planned power sales amount, which is the power sales amount in the charge / discharge plan. The charge / discharge control system according to claim 1.

7. The control unit stops discharging the storage battery when the actual charge amount of the storage battery becomes equal to or less than a predetermined value. The charge / discharge control system according to claim 6.

8. The control unit charges the storage battery by the difference between the actual power generation amount and the planned power sales amount when the actual power generation amount is equal to or greater than the planned power sales amount. The charge / discharge control system according to claim 6.

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