Power demand-supply management system, control method for storage battery system, storage battery system, and external system

Abstract

To more effectively utilize introduced asset in comparison with a case where a supply command of an adjustment force is not acquired from a market system.SOLUTION: A power demand-supply management system comprises: a storage battery capable of charging or discharging power; prediction means for predicting a consumption power amount required for an important load, to which power is supplied in the case of power failure among loads to which power is supplied from a power network; setting means for setting a lower limit value of a charging amount of the storage battery on the basis of the predicted consumption power amount; acquisition means for acquiring from a market system a supply command of an adjustment force that is power to be used for adjusting demand and supply; and control means for executing a charging / discharging operation of the storage battery so as to supply, on the basis of the supply command, the adjustment force within a range, which is not below the lower limit value of the charging amount.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power supply and demand management system, a control method for a storage battery system, a storage battery system, and an external system. [Background technology]

[0002] Patent Document 1 discloses a power supply system that aims to enable a load that receives power from a storage battery during a power outage to be able to continue to supply power during normal times without interfering with the power supply during a power outage, and that includes: a power supply device; a storage battery that supplies power to the load during a power outage of the power supply device; a power supply capability determination unit that determines whether the power that can be supplied from the power supply device is insufficient for the power required by the load; a storage amount determination unit that determines whether the amount of stored power in the storage battery is greater than a determination reference value for whether the required power can be supplied to the load during a power outage of the power supply device; and a charge / discharge control unit that causes the storage battery to discharge when the power supply capability determination unit determines that the suppliable power is insufficient for the required power and the storage amount determination unit determines that the stored power is greater than the determination reference value while the power supply device is supplying power to the load. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2018-143033 Summary of the Invention [Problem to be solved by the invention]

[0004] Backup for critical loads in the event of a power outage is usually performed using an uninterruptible power supply (UPS). However, when power outages are infrequent, many storage batteries and power sources reach the end of their lifespan without experiencing a power outage. Also, storage battery capacity (kWh) is typically larger than expected in anticipation of deterioration, and power supply capacity (kVA, kW) is selected to match the peak power consumption of critical loads, resulting in excessive equipment in many cases. For these reasons, the current situation is that installed assets are not being used effectively.

[0005] The present invention aims to make more effective use of introduced assets compared to a case where no adjustment reserve provision command is obtained from the market system. [Means for solving the problem]

[0006] The invention described in claim 1 is an electricity supply and demand management system comprising: a storage battery capable of charging or discharging electricity; a prediction means for predicting the amount of power consumption required for important loads that are supplied with electricity from the power grid during a power outage; a setting means for setting a lower limit of the charge amount of the storage battery based on the predicted amount of power consumption; an acquisition means for acquiring from a market system a command to provide adjustment capacity, which is electricity used to adjust supply and demand; and a control means for executing charging and discharging operations of the storage battery based on the supply command so that the adjustment capacity can be provided within a range that does not fall below the lower limit of the charge amount. The invention described in claim 2 is the power supply and demand management system described in claim 1, characterized in that the control means acquires a current charge amount, which is the current charge amount in the storage battery, calculates the amount of electricity that can be provided as the adjustment power from the current charge amount, and executes the charging and discharging operation based on the amount of electricity. The invention described in claim 3 is the power supply and demand management system described in claim 2, characterized in that the control means calculates the amount of electricity that can be provided as the adjustment power from the current charge amount and the lower limit value of the charge amount, and executes a discharge operation based on this amount of electricity. The invention described in claim 4 is the power supply and demand management system described in claim 1, characterized in that the control means performs a charging operation on the storage battery in advance so that the lower limit value of the charge amount is ensured in the storage battery. The invention described in claim 5 is the power supply and demand management system described in claim 4, characterized in that the control means causes the storage battery to perform a charging operation in advance so as to ensure that the amount of electricity that can be provided to the storage battery as the adjustment capacity is secured. The invention described in claim 6 is the electricity supply and demand management system described in claim 1, characterized in that the control means determines the lower limit value of the charge amount by taking into account a lower limit value of the available power predetermined for the storage battery into account. The invention described in claim 7 is the power supply and demand management system according to claim 1, characterized in that the setting means sets the lower limit value of the charge amount at predetermined intervals. The invention described in claim 8 is an electricity supply and demand management system comprising a storage battery system including a storage battery capable of charging or discharging electricity, and an external system connected to the storage battery system via a network and controlling the storage battery system, wherein the storage battery system predicts the amount of power consumption required for important loads that are supplied with electricity from the power grid during a power outage, sets a lower limit for the amount of charge of the storage battery based on the predicted amount of power consumption, and outputs the lower limit for the amount of charge to the external system via the network, and the external system obtains from a market system a command to provide adjustment capacity, which is electricity used to adjust supply and demand, and based on the command to provide, outputs a command to the storage battery system regarding the charging and discharging operation of the storage battery so that the adjustment capacity can be provided within a range that does not fall below the lower limit for the amount of charge. The invention described in claim 9 is a method for controlling a storage battery system including a storage battery capable of charging or discharging power, which comprises predicting the amount of power consumption required for important loads that are supplied with power from a power grid during a power outage, setting a lower limit for the amount of charge of the storage battery based on the predicted amount of power consumption, obtaining from a market system a command to provide adjustment capacity, which is power used to adjust supply and demand, and, based on the command to provide adjustment capacity, executing charging and discharging operations of the storage battery so that the amount of charge does not fall below the lower limit. The invention described in claim 10 is a storage battery system including a storage battery capable of charging or discharging power, which predicts the amount of power consumption required for important loads that are supplied with power from a power grid and that will receive power during a power outage, sets a lower limit for the charge amount of the storage battery based on the predicted amount of power consumption and outputs the set lower limit to an external system, obtains from the external system instructions regarding the charging and discharging operations of the storage battery that are set within a range that does not fall below the lower limit of the charge amount, and performs the charging and discharging operations of the storage battery based on the obtained instructions. The invention described in claim 11 is an external system that controls a storage battery system including a storage battery capable of charging or discharging power, characterized in that the external system obtains from the storage battery system a lower limit of the charge amount of the storage battery, which is set based on the amount of power consumption required for important loads that are supplied with power from a power grid and that will be supplied with power during a power outage, obtains from a market system a command to supply adjustment power, which is power used to adjust supply and demand, and based on the command to supply power, outputs a command to the storage battery system to charge or discharge the storage battery within a range that does not fall below the lower limit of the charge amount. [Effects of the Invention]

[0007] According to the present invention, the introduced assets can be utilized more effectively than when a command to provide adjustment capacity is not obtained from the market system. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating an example of an embodiment including a power supply and demand management system. [Figure 2] FIG. 2 is a diagram illustrating an example of the hardware configuration of the storage battery system and an external system according to the present embodiment. [Figure 3] 10 is a diagram illustrating an example in which the control unit predicts the amount of power consumption of a significant load for each predetermined period. FIG. [Figure 4] 4 is a flowchart illustrating the procedure of a control process performed by a control unit of the storage battery system. [Figure 5] FIG. 2 is a diagram illustrating an example of a charging state of a storage battery. [Figure 6] FIG. 10 is a diagram showing an example of a pre-charging operation for a storage battery. [Figure 7] 10 is a flowchart illustrating a procedure of a control process performed by a control unit of an external system. [Figure 8] FIG. 10 is a diagram illustrating an example of control for preventing deterioration of a storage battery. [Figure 9] FIG. 1 is a diagram illustrating an example of a storage battery with a limited range of available power. [Figure 10] FIG. 10 is a diagram illustrating another example of a storage battery with a limited range of available power. [Figure 11] FIG. 10 is a diagram illustrating another example of a pre-charging operation for a storage battery. [Figure 12] FIG. 1 is a diagram illustrating an example of a continuous inverter type uninterruptible power supply. [Figure 13] FIG. 1 is a diagram illustrating an example of a parallel processing type uninterruptible power supply. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. <Configuration of the electricity supply and demand management system> FIG. 1 is a diagram showing an example of the present embodiment including a power supply and demand management system. The electricity supply and demand management system in this embodiment includes a storage battery system 1 and an external system 2. The storage battery system 1 is a system that controls charging to or discharging from the storage battery 12. The external system 2 is a system that receives commands from a market system 3 and manages the storage battery system 1 based on the commands. In this embodiment, the external system 2 manages multiple storage battery systems 1. FIG. 1 shows one storage battery system 1 among the multiple storage battery systems 1. The storage battery system 1 and the external system 2 are connected via a network 100 and transmit and receive various types of information. The external system 2 is also connected to the market system 3 via the network 100 and transmits and receives various types of information.

[0010] The network 100 is an information communication network that handles communication between the various systems. The type of the network 100 is not particularly limited as long as it is capable of transmitting and receiving data, and it may be, for example, the Internet, a Wide Area Network (WAN), or the like. The communication line used for data communication may be wired or wireless, or a combination of these. Furthermore, the various systems may be connected via multiple networks or communication lines.

[0011] The market system 3 is a system for adjusting the balance between electricity demand and supply and for operating the electricity network flexibly and efficiently. The market system 3 is managed, for example, by an operator of the electricity network. The market system 3 provides a command to provide adjustment capacity, which is electricity used to adjust supply and demand. An adjustment capacity provision command is a command issued to adjust the supply and demand of electricity. More specifically, it is a command to request a reduction in electricity demand or a command to request an increase in electricity demand.

[0012] In Fig. 1, the solid lines connecting the components correspond to power lines that supply power. The dashed lines connecting the components correspond to communication lines that communicate information and data. The components may communicate with each other via wires or wirelessly.

[0013] The storage battery system 1 in this embodiment is used, for example, in a customer facility. The customer facility refers to a facility in which devices and equipment that consume power are installed. Examples of the customer facility include homes, offices, and factories. At the customer facility, power is supplied from a power grid 4 via power lines to the devices and equipment that consume power. In FIG. 1 , the devices and equipment that consume power are shown as loads, and are labeled as general loads 5 and important loads 6. The general loads 5 are power demands that are met by normal power supply unless a power outage or the like occurs. The important loads 6 are important power demands that need to be maintained even in the event of a power outage or the like. The amount of power consumed by these loads varies depending on the time of day. The storage battery system 1 in this embodiment is connected to a power grid 4. The storage battery system 1 may charge a storage battery 12 with power supplied from the power grid 4.

[0014] As shown in Fig. 1, a voltage sensor 7 that detects voltage is provided between the power grid 4 and the battery storage system 1. The voltage sensor 7 detects a power outage by detecting a sudden drop in voltage. The voltage sensor 7 also detects a restoration of power by detecting that the voltage has returned to a normal range.

[0015] The battery system 1 includes a bidirectional inverter 11, a battery 12, a control unit 13, and a communication unit 14. The battery system 1 also includes a power sensor 15 and a switch 16.

[0016] The bidirectional inverter 11 is a power conversion device capable of converting AC power and DC power mutually. As shown in FIG. 1, the bidirectional inverter 11 is connected between a power grid 4 and a storage battery 12. The side of the bidirectional inverter 11 connected to the power grid 4 is also connected to a general load 5 and an important load 6. The bidirectional inverter 11 receives AC power and outputs AC power on the side connected to the power grid 4 and the general load 5 and important load 6. Therefore, in FIG. 1, the side of the bidirectional inverter 11 connected to the power grid 4 is also called the AC side.

[0017] Furthermore, the bidirectional inverter 11 receives and outputs DC power on the side connected to the storage battery 12. Therefore, in FIG. 1, the side of the bidirectional inverter 11 to which the storage battery 12 is connected is also called the DC side.

[0018] The bidirectional inverter 11 is configured so that its AC side and DC side can be connected to each other. The bidirectional inverter 11 receives AC power from the AC side, converts it into DC power, and outputs it to the DC side. The bidirectional inverter 11 also receives DC power from the DC side, converts it into AC power, and outputs it to the AC side. In other words, the bidirectional inverter 11 converts AC power to DC power and vice versa.

[0019] The bidirectional inverter 11 performs a discharging operation from the DC side including the storage battery 12 to the AC side including the load. The bidirectional inverter 11 also performs a charging operation from the AC side connected to the power grid 4 to the DC side including the storage battery 12.

[0020] The storage battery 12 can store power using DC power. The storage battery 12 is charged with DC power supplied from the bidirectional inverter 11 and discharges the DC power to the bidirectional inverter 11. The storage battery 12 includes, for example, a lead storage battery or a lithium ion battery.

[0021] The control unit 13 controls each component of the storage battery system 1. The communication unit 14 communicates with the external system 2 and transmits and receives various information.

[0022] The power sensor 15 is provided between the important load 6 and the bidirectional inverter 11. The power sensor 15 measures the amount of power consumed by the important load 6.

[0023] The switch 16 is provided between the power grid 4 and the bidirectional inverter 11. The switch 16 transitions to either a closed state in which the power line is conductive, or an open state in which the power line is interrupted. The control unit 13 controls the switch 16 to open and close it.

[0024] When the power grid 4 is conductive, the control unit 13 transitions the switch 16 to a closed state to connect the storage battery system 1 to the power grid 4 so that power is supplied from the power grid 4 to the storage battery system 1. When the power grid 4 is experiencing a power outage, the control unit 13 transitions the switch 16 to an open state to disconnect the storage battery system 1 from the power grid 4 so that the storage battery system 1 is not affected by the power grid 4.

[0025] The external system 2 includes a communication unit 21 and a control unit 22. The communication unit 21 of the external system 2 communicates with the storage battery system 1 and the market system 3 via the network 100, and transmits and receives various information. The control unit 22 of the external system 2 receives commands from the market system 3 via the communication unit 21, and manages the storage battery system 1 based on the commands.

[0026] <Hardware configuration of the battery storage system and external system> FIG. 2 is a diagram illustrating an example of the hardware configuration of the storage battery system 1 and the external system 2 according to this embodiment. The storage battery system 1 and the external system 2 each include a CPU (Central Processing Unit) 51 as an example of a processor, a ROM (Read Only Memory) 52, and a RAM (Random Access Memory) 53. The CPU 51 uses the RAM 53 as a work area and executes programs read from the ROM 52. The storage battery system 1 and the external system 2 each include a communication interface 54 for connecting to a network. The storage battery system 1 and the external system 2 may also include a display device 55 for displaying output on a display and an input device 56 through which an operator performs input operations. Note that the configurations of the storage battery system 1 and the external system 2 shown in FIG. 2 are merely examples, and the computers used in this embodiment are not limited to the configuration example shown in FIG. 2.

[0027] <Control of battery storage system and external systems> Hereinafter, the control processing performed by the control unit 13 of the storage battery system 1 and the control unit 22 of the external system 2 will be described with reference to FIGS.

[0028] In this embodiment, the control unit 13 of the storage battery system 1 predicts the amount of power consumption required for backup of the important loads 6 among the loads to which power is supplied from the power grid 4 at each predetermined cycle. The amount of power consumption required for backup of the important loads 6 can be predicted from various information, such as the date of the month, day of the week, time period, season, current temperature, current power consumption of the important loads 6, and past power consumption history. The cycle for making the prediction can be arbitrarily set by the user. For example, it may be in minutes or hours.

[0029] FIG. 3 is a diagram showing an example in which the control unit 13 predicts the amount of power consumption of the important load 6 for each predetermined period. In Fig. 3, the vertical axis represents the amount of power consumption (kWh) required for backup of the important load 6, and the horizontal axis represents time (t). When a predetermined period occurs, the control unit 13 predicts the amount of power consumption required for backup of the important load 6 in the time period to which the period belongs. As an example, Fig. 3 shows the amount of power consumption required for backup of the important load 6 predicted by the control unit 13 in each of the time periods t1, t2, t3, ..., tn. The control unit 13 of the battery storage system 1 predicts and updates the amount of power consumption required for backup of the important load 6, which varies throughout the day, for each predetermined period. Hereinafter, the predetermined period will be referred to as the update period.

[0030] The amount of power consumption required for backing up the important loads 6 can be predicted based on the various types of information described above. The control unit 13 of the storage battery system 1 may predict the amount of power consumption required for backing up the important loads 6 in the next update period in advance, before the next update period arrives.

[0031] <Control process procedure for battery storage system> FIG. 4 is a flowchart illustrating the procedure of the control process performed by the control unit 13 of the storage battery system 1. Here, an example will be described in which a command to request a reduction in power demand is received as a supply command of adjustment power from the market system 3. In this case, the power demand can be reduced by reducing the power received from the power grid 4. For example, the power demand from the power grid 4 can be reduced by discharging the power stored in the storage battery 12 and supplying power to the AC side.

[0032] When an update period arrives, the control unit 13 of the storage battery system 1 uses various information used for prediction to predict the amount of power consumption currently required for backup of the important loads 6, and calculates the remaining battery capacity A (kWh) required for backup (S101). This remaining battery capacity A is the amount of power that can be discharged from the storage battery 12.

[0033] Next, the control unit 13 of the storage battery system 1 sets a lower limit value for the charge amount of the storage battery 12 so as to ensure the remaining storage battery amount A calculated in S101 (S102).

[0034] FIG. 5 is a diagram showing an example of the charging state of the storage battery 12. As shown in FIG. In the example shown in FIG. 5, the maximum amount of power that can be stored in the storage battery 12 is the total storage capacity B (kWh). The total storage capacity B has a state of charge (SOC) (%) of 100%. The state of charge (%) is calculated by (remaining battery capacity A / total storage capacity B) × 100%. The control unit 13 of the storage battery system 1 sets a lower limit C% of the charge amount so as to ensure the remaining battery capacity A calculated in S101. For example, in FIG. 5, an amount of power equal to or less than the lower limit C of the charge amount, that is, an amount of power indicated by a diagonal line (L), is ensured in the storage battery 12 as power required for backing up the important load 6. The control unit 13 of the storage battery system 1 controls the power stored in the storage battery 12 so that it can be used within a range from SOC 100% to the lower limit C of the charge amount, as indicated by an arrow X. Note that the state of charge of the storage battery 12 may be controlled based on the actual amount of power without using the SOC.

[0035] Returning to Figure 4, the flow will be explained. Next, the control unit 13 of the storage battery system 1 transmits the lower limit value C of the charge amount set in S102 to the external system 2 via the communication unit 14 (S103).

[0036] Furthermore, the control unit 13 of the storage battery system 1 focuses on the current charge amount of the storage battery 12 (hereinafter, the current charge amount may be referred to as the "current charge amount"), and if the current charge amount of the storage battery 12 is lower than the lower limit C of the charge amount set in S102 (NO in S104), it causes the bidirectional inverter 11 to execute a charging operation on the storage battery 12 so that the current charge amount of the storage battery 12 becomes higher than the set lower limit C of the charge amount (S105). If the current charge amount of the storage battery 12 is higher than the lower limit C of the charge amount set in S102 (YES in S104), the process proceeds to S106.

[0037] In the above example, when an update period arrives, the control unit 13 of the storage battery system 1 predicts the amount of power consumption required for backup of the important load 6 during the time period to which the update period belongs. Meanwhile, when an update period arrives, the control unit 13 of the storage battery system 1 may also predict the amount of power consumption required for backup of the important load 6 during the time period to which the next period belongs. If the control unit 13 predicts that the amount of power consumption of the important load 6 will increase during the time period to which the next period belongs, it may set a lower limit C of the charge amount of the storage battery 12 so as to ensure the amount of power consumption required during the time period to which the next period belongs. Then, before the next period begins, the control unit 13 may cause the bidirectional inverter 11 to execute a charging operation on the storage battery 12 in advance so that the charge amount of the storage battery 12 becomes higher than the set lower limit C of the charge amount.

[0038] FIG. 6 is a diagram showing an example of a pre-charging operation for the storage battery 12. In FIG. Here, the SOC is adjusted in advance taking into account the load prediction. In FIG. 6, the vertical axis represents the power consumption (kWh) required for backup of the important load 6, and the horizontal axis represents time (t). Here, for example, t3 is assumed to be the present. At t3, the control unit 13 of the storage battery system 1 predicts the power consumption required for backup of the important load 6 at the next time point, t4. If it is predicted that the power consumption of the important load 6 will increase at t4, a lower limit C of the charge amount of the storage battery 12 is set so that the required power consumption is ensured at t4. Then, before t4, a charging operation is performed on the storage battery 12 in advance so that the charge amount of the storage battery 12 is higher than the set lower limit C of the charge amount. As a result, when t4 arrives, the lower limit C of the charge amount based on the predicted power consumption of the important load 6 is ensured in the storage battery 12.

[0039] Returning to Figure 4, the flow will be explained. The control unit 13 of the battery system 1 checks whether a supply command value has been received from the external system 2 (S106). The supply command value is a charge / discharge command value used to adjust the supply and demand of power. The supply command value is specified by power (kW) and time. For example, the supply command value is set to "100 kW for 30 minutes," and a supply command for regulation power is output from the external system 2. When the control unit 13 of the battery system 1 receives a supply command value from the external system 2 (YES in S106), the control unit 13 discharges regulation power based on the supply command value from the storage battery 12 to the AC side via the bidirectional inverter 11 (S107). When the control unit 13 of the battery system 1 has not received a supply command value from the external system 2 (NO in S106), the control unit 13 waits (proceeds to S108).

[0040] Next, if a power outage has not occurred (NO in S108), the control unit 13 of the storage battery system 1 determines whether the update period has elapsed (S109). If the update period has elapsed (YES in S109), the process returns to S101, where a new amount of power consumption required for backup of the important load 6 is predicted, and the required remaining battery capacity A is calculated. On the other hand, if the update period has not elapsed (NO in S109), the process returns to S104.

[0041] If a power outage occurs (YES in S108), the control unit 13 of the battery system 1 switches the switch 16 to an open state, and switches the battery system 1 to independent operation (S110). Then, the control unit 13 supplies power to the important load 6 using the power stored in the battery 12 (S111).

[0042] Thereafter, if the voltage sensor 7 detects that power has been restored (YES in S112), the control unit 13 returns to S109. If the voltage sensor 7 does not detect that power has been restored (NO in S112), the control unit 13 determines whether or not there is a remaining charge in the storage battery 12 (S113). If there is a remaining charge in the storage battery 12 (YES in S113), the control unit 13 returns to S111 and continues to supply power to the important load 6. If there is no remaining charge in the storage battery 12 (NO in S113), the power supply from the storage battery 12 is stopped (S114).

[0043] <External system control process procedure> Next, the processing of the external system 2 will be described. Although the external system 2 manages a plurality of storage battery systems 1, the processing for one storage battery system 1 will be described here.

[0044] FIG. 7 is a flowchart for explaining the procedure of the control process performed by the control unit 22 of the external system 2. When the lower limit value C of the charge amount is transmitted from the battery system 1, the control unit 22 of the external system 2 acquires the lower limit value C of the charge amount (S201). Then, the control unit 22 of the external system 2 checks whether or not a command to provide adjustment capacity has been received from the market system 3 (S202). This check may be performed at regular time intervals. If a command to provide adjustment capacity has been received from the market system 3 (YES in S202), the control unit 22 of the external system 2 acquires the current charge amount of the storage battery 12 from the battery system 1 (S203). Then, the control unit 22 of the external system 2 calculates the amount of power available for the storage battery 12 from the current charge amount and the lower limit value C of the charge amount of the storage battery 12, and calculates a supply command value based on the calculated value (S204). Then, the control unit 22 of the external system 2 outputs a command to provide adjustment capacity together with the calculated supply command value to the battery system 1 (S205). As a result, the control unit 13 of the storage battery system 1 executes a discharge operation from the storage battery 12 so that the adjustment power can be provided based on the supply command value. Note that if the command to provide adjustment power has not been received from the market system 3 (NO in S202), the control unit 13 waits (proceeds to S206).

[0045] The control unit 22 of the external system 2 checks whether a new lower limit value C of the charge amount has been received from the storage battery system 1 (S206). If the control unit 22 of the external system 2 has received a new lower limit value C of the charge amount from the storage battery system 1 (YES in S206), the control unit 22 returns to S201 and acquires the lower limit value C of the charge amount. On the other hand, if a new lower limit value C of the charge amount has not been received (NO in S206), the control unit 22 returns to S202 and waits.

[0046] The above describes the control process steps performed by the control unit 13 of the battery system 1 and the control unit 22 of the external system 2 when a command requesting a reduction in power demand is received as a command to provide adjustment capacity from the market system 3. On the other hand, when a command requesting an increase in power demand is received as a command to provide adjustment capacity from the market system 3, the increase in power demand can be achieved by charging the storage battery 12 with power supplied from the power grid 4.

[0047] In this case, the control unit 22 of the external system 2 calculates the amount of charge that can be charged to the storage battery 12 from the current charge amount of the storage battery 12 and the total storage capacity B of the storage battery 12, and calculates a supply command value based on the calculated value. Then, together with the calculated supply command value, it outputs a supply command for the adjustment force to the storage battery system 1. As a result, the control unit 13 of the storage battery system 1 executes a charging operation for the storage battery 12 so that the adjustment force based on the supply command value can be supplied.

[0048] Here, the flow in which the external system 2 outputs a command to one storage battery system 1 has been described. In reality, the external system 2 manages a plurality of storage battery systems 1. The external system 2 redistributes the supply command for the adjustment force from the market system 3 according to the charge state of the storage battery 12 of each storage battery system 1 managed by the external system 2.

[0049] <Control to reduce deterioration of storage battery> FIG. 8 is a diagram showing an example of control to prevent deterioration of the storage battery 12. As an example of the storage battery 12, for example, a lithium-ion battery tends to deteriorate if it stays at the lower or upper limit of the state of charge (SOC) for a long time. Therefore, the control unit 22 of the external system 2 performs control to prevent deterioration of the storage battery 12. Specifically, when the power consumption of the important load 6 is small and there is no utilization of the adjustment force, the control unit 22 of the external system 2 outputs an instruction for charge and discharge to the storage battery system 1 so that the charge amount is maintained within a predetermined range. For example, it is assumed that when the charge amount of the storage battery 12 is 20% or less, or 80% or more with respect to the total storage capacity B, the storage battery 12 tends to deteriorate. If this charge state continues, the deterioration of the storage battery 12 tends to progress. When the power consumption of the important load 6 is small and there is no utilization of the adjustment force, the control unit 22 of the external system 2 outputs an instruction for charge and discharge so that the charge amount is maintained within the range of 20% to 80% with respect to the total storage capacity B. As a result, the charge amount of the storage battery 12 is maintained within the range indicated by the arrow Y in FIG. 8, and deterioration of the storage battery 12 can be prevented.

[0050] <When there are restrictions on the upper and lower limits of SOC> FIG. 9 is a diagram showing an example of a storage battery 12 in which the range of available power is limited. A storage battery may have a restriction on the range of its available power. For example, in FIG. 9 , the range of available power of the storage battery 12 is limited to an SOC of 10% to 90% of the total storage capacity B. In this case, the control unit 22 of the external system 2 adds 10%, which is the lower limit of available power, to the set lower limit C of the amount of charge (the area indicated by diagonal lines (L)), and sets the lower limit C of the amount of charge to C+10%. Also, the upper limit D of the amount of charge is set to 90%. The control unit 22 of the external system 2 then controls the power of the storage battery 12 to be available within the range of C+10% to 90% (the range indicated by arrow Z). This prevents a situation in which the amount of power consumed by the storage battery 12 required for backing up the important load 6 is insufficient, even when a storage battery 12 with a restricted range of available power is used.

[0051] <When considering battery deterioration> FIG. 10 is a diagram showing another example of a storage battery 12 in which the range of available power is limited. The performance of a storage battery may deteriorate over time. For example, as shown in FIG. 10, assume that the storage battery 12 has deteriorated by 20% of its original total storage capacity B. In this case, the control unit 22 of the external system 2 uses the acquired value for the lower limit C of the charge amount as is. The control unit 22 of the external system 2 uses 80% for the upper limit D of the charge amount. The control unit 22 of the external system 2 then controls the power of the storage battery 12 to be usable within a range from the lower limit C of the charge amount to 80% (the range indicated by the arrow W). In this way, even if the storage battery 12 has deteriorated, it is possible to determine whether or not adjustment capability can be provided, taking into account the deterioration.

[0052] <Adjust SOC in advance taking into account market forecasts> FIG. 11 is a diagram showing another example of the pre-charging operation for the storage battery 12. In FIG. Here, the SOC is adjusted in advance, taking into account market forecasts.,In Fig. 11, the vertical axis represents the,power consumption (kWh) required for backup of critical load 6,,and the horizontal axis represents time (t).

[0053] For example, the market system 3 may issue a command to provide adjustment capacity with a certain grace period in order to reduce power consumption during peak power demand. The control unit 22 of the external system 2 may want to output a larger supply command value to the battery system 1 in order to reduce power consumption during peak power demand. Therefore, the external system 2 instructs the battery system 1 to perform a charging operation in advance. This will be described below with reference to FIG. 11.

[0054] For example, let us assume that the present is t5. The market system 3 issues a command to provide regulation capacity in accordance with the peak of power demand (e.g., time t6). First, the control unit 13 of the battery storage system 1 predicts the amount of power consumption (area indicated by L in the figure) required for backup of the important load 6 at time t6. Based on the prediction, the control unit 13 sets a lower limit C of the charge amount and transmits the lower limit C to the external system 2. Meanwhile, the control unit 22 of the external system 2 sets the amount of power (area indicated by M in the figure) expected to be discharged from the battery storage system 1 at time t6. The control unit 22 of the external system 2 then instructs the battery storage system 1 to perform a charging operation in advance so that the amount of power (L+M) is met in accordance with the peak of power demand (here, t6). As a result, the battery storage system 12 is charged in advance before time t6 arrives. This ensures that the lower limit C of the charge amount and the amount of power required to provide regulation capacity are secured in the battery storage system 1 when time t6 arrives.

[0055] <Another embodiment 1> 1, a storage battery system 1 is used. Here, a continuous inverter type uninterruptible power supply device 200 will be described as an alternative system to the storage battery system 1.

[0056] FIG. 12 is a diagram showing an example of a continuous inverter type uninterruptible power supply 200. In FIG. A continuous inverter type uninterruptible power supply 200 is connected to a power grid 4 and an important load 6. The uninterruptible power supply 200 includes, for example, a rectifier 201, an inverter 202, a storage battery 203, a control unit 204, and a communication unit 205. In addition, a power sensor 206 is provided between the important load 6 and the inverter 202. The power sensor 206 measures the amount of power consumed by the important load 6.

[0057] The rectifier 201 converts AC power supplied from the power grid 4 into DC power. The inverter 202 converts DC power output from the rectifier 201 and the storage battery 203 into AC power and supplies it to the important load 6. The storage battery 203 can store power as DC power. The storage battery 203 is charged with the DC power supplied from the rectifier 201 and outputs the DC power to the inverter 202. The storage battery 12 is configured to include, for example, a lead storage battery, a lithium ion battery, or the like.

[0058] The control unit 204 of the uninterruptible power supply 200 acquires the charge state of the storage battery 203, for example, the charge amount, from the storage battery 203. The control unit 204 also acquires the amount of power consumed by the important load 6 from the power sensor 206. The control unit 204 of the uninterruptible power supply 200 also predicts the amount of power consumed by the important load 6 and sets a lower limit C of the charge amount so as to ensure the power necessary for backing up the important load 6. In this way, the control unit 204 of the uninterruptible power supply 200 manages the amount of stored power to be left for backing up the important load 6. The control unit 204 of the uninterruptible power supply 200 also receives a command to provide adjustment power from the external system 2 and controls the charging and discharging of the storage battery 203. In the event of a power outage, the control unit 204 of the uninterruptible power supply 200 switches the uninterruptible power supply 200 to independent operation and causes it to start supplying power to the important load 6.

[0059] The communication unit 205 of the uninterruptible power supply 200 transmits various information, such as the set lower limit value C of the charge amount and the charge state of the storage battery 203, to the external system 2. The communication unit 205 also receives a command to provide adjustment power from the external system 2.

[0060] The control unit 22 of the external system 2 issues a command to the uninterruptible power supply 200 to provide adjustment capability, while ensuring the lower limit C of the charge amount acquired from the uninterruptible power supply 200, within a range that does not fall below the lower limit C of the charge amount. The communication unit 21 of the external system 2 receives various information from the market system 3 and the uninterruptible power supply 200. The communication unit 21 also transmits a command to the uninterruptible power supply 200 to provide adjustment capability.

[0061] The uninterruptible power supply 200 differs from the grid-connected battery system 1 in that it supplies power from the power grid 4 in one direction to the important load 6. Although there is a limit to the provision of adjustment power in that the power that can be discharged from the battery 12 is limited to the output of the important load 6, it is also possible to apply the control processing procedures of the battery system 1 to the uninterruptible power supply 200.

[0062] <Another embodiment 2> Furthermore, as an alternative system to the storage battery system 1, a parallel processing type uninterruptible power supply device 300 will be described.

[0063] FIG. 13 is a diagram illustrating an example of a parallel processing type uninterruptible power supply 300. As shown in FIG. A parallel processing type uninterruptible power supply 300 is connected to a power grid 4 and a critical load 6. The uninterruptible power supply 300 includes, for example, a bidirectional inverter 301, a storage battery 302, a control unit 303, a communication unit 304, a power sensor 305, and a switch 306.

[0064] The bidirectional inverter 301 converts AC power supplied from the power grid 4 into DC power and charges the storage battery 302. It also converts DC power output from the storage battery 302 into AC power and discharges it. However, unlike the grid-connected type, it can only discharge up to the output of the important load 6. The storage battery 302 can store power as DC power. The storage battery 302 includes, for example, a lead-acid battery or a lithium-ion battery. The power sensor 305 measures the amount of power consumed by the important load 6. When the power grid 4 is conductive, the switch 306 transitions to a closed state to connect to the power grid 4. When a power outage occurs in the power grid 4, the switch 306 transitions to an open state to supply power only to the important load 6 without momentary interruption.

[0065] The control unit 303 of the uninterruptible power supply 300 acquires the charge state of the storage battery 302, for example, the charge amount, from the storage battery 302. The control unit 303 also acquires the amount of power consumed by the important load 6 from the power sensor 305. The control unit 303 of the uninterruptible power supply 300 also predicts the amount of power consumed by the important load 6 and sets a lower limit C of the charge amount so as to ensure the power necessary for backing up the important load 6. In this way, the control unit 303 of the uninterruptible power supply 300 manages the amount of stored power to be left for backing up the important load 6. The control unit 303 of the uninterruptible power supply 300 also receives a command to provide adjustment power from the external system 2 and controls the charging and discharging of the storage battery 302. In the event of a power outage, the control unit 303 of the uninterruptible power supply 300 switches the uninterruptible power supply 300 to independent operation and causes it to start supplying power to the important load 6.

[0066] The communication unit 304 of the uninterruptible power supply 300 transmits various information, such as the set lower limit C of the charge amount and the charge state of the storage battery 302, to the external system 2. The communication unit 304 also receives a command to provide adjustment power from the external system 2.

[0067] The control unit 22 of the external system 2 issues a command to the uninterruptible power supply 300 to provide adjustment capability, while ensuring the lower limit C of the charge amount acquired from the uninterruptible power supply 300, within a range that does not fall below the lower limit C of the charge amount. The communication unit 21 of the external system 2 receives various information from the market system 3 and the uninterruptible power supply 300. The communication unit 21 also transmits a command to the uninterruptible power supply 300 to provide adjustment capability.

[0068] The uninterruptible power supply 300 differs from the grid-connected battery system 1 in that it supplies power from the power grid 4 in one direction to the important load 6. The power that can be discharged from the battery 12 is limited to the output of the important load 6, so there is a limit to the provision of adjustment power. However, the control processing procedures of the battery system 1 can also be applied to the uninterruptible power supply 300.

[0069] Although the embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the above-described embodiments. Some or all of the functions of the control unit 13 of the storage battery system 1 may be executed by the control unit 22 of the external system 2. For example, the external system 2 may calculate the remaining battery capacity A of the storage battery 12 and set the lower limit C of the charge amount. Various other modifications and alternative configurations that do not depart from the scope of the technical concept of the present invention are included in the present invention. [Explanation of symbols]

[0070] 1... Battery storage system, 2... External system, 3... Market system, 4... Power grid, 5... General load, 6... Important load, 7... Voltage sensor, 11... Bidirectional inverter, 12... Storage battery, 15... Power sensor, 16... Switch, 200... Continuous inverter type uninterruptible power supply, 300... Parallel processing type uninterruptible power supply

Claims

1. a storage battery capable of charging or discharging power; a prediction means for predicting the amount of power consumption required for important loads to which power is supplied during a power outage, among the loads to which power is supplied from the power grid; a setting means for setting a lower limit of the charge amount of the storage battery based on the predicted power consumption amount; An acquisition means for acquiring, from a market system, a command to provide adjustment power, which is electricity used to adjust supply and demand; a control means for executing a charge / discharge operation of the storage battery based on the supply command so that the adjustment power can be supplied within a range that does not fall below the lower limit value of the charge amount; An electric power supply and demand management system comprising:

2. The control means acquires a current charge amount, which is a current charge amount in the storage battery, calculates an amount of power that can be provided as the adjustment capability from the current charge amount, and executes the charge / discharge operation based on the calculated amount of power. The power supply and demand management system according to claim 1 .

3. The control means calculates an amount of power that can be provided as the adjustment capability from the current charge amount and a lower limit value of the charge amount, and executes a discharging operation based on the calculated amount of power. The power supply and demand management system according to claim 2,

4. The control means causes the storage battery to be charged in advance so that the lower limit value of the charge amount is ensured in the storage battery. The power supply and demand management system according to claim 1 .

5. The control means causes the storage battery to perform a charging operation in advance so as to ensure an amount of power that can be supplied to the storage battery as the adjustment power. The power supply and demand management system according to claim 4,

6. The control means determines the lower limit of the charge amount by adding a lower limit of the available power predetermined for the storage battery to the set lower limit of the charge amount. The power supply and demand management system according to claim 1 .

7. The setting means sets the lower limit value of the charge amount at predetermined intervals. The power supply and demand management system according to claim 1 .

8. a storage battery system including a storage battery capable of charging or discharging power; an external system connected to the battery system via a network and controlling the battery system; An electric power supply and demand management system comprising: The storage battery system includes: The system predicts the amount of power consumption required for important loads that will receive power during a power outage, among the loads that receive power from the power grid, and setting a lower limit value of the charge amount of the storage battery based on the predicted power consumption amount; outputting the lower limit value of the charge amount to the external system via the network; The external system Obtaining a supply command for balancing power, which is the electricity used to adjust supply and demand, from the market system, outputting a command to the battery system regarding a charging / discharging operation of the storage battery so that the adjustment power can be provided within a range not falling below the lower limit value of the charge amount based on the supply command; An electricity supply and demand management system characterized by the above.

9. A method for controlling a battery system including a battery capable of charging or discharging power, comprising: The system predicts the amount of power consumption required for important loads that will receive power during a power outage, among the loads that receive power from the power grid, and setting a lower limit value of the charge amount of the storage battery based on the predicted power consumption amount; Obtaining a supply command for balancing power, which is the electricity used to adjust supply and demand, from the market system, Executing a charging / discharging operation of the storage battery so that the adjustment power can be provided within a range that does not fall below the lower limit value of the charge amount based on the supply command. A control method for a storage battery system, comprising:

10. A storage battery system including a storage battery capable of charging or discharging power, The system predicts the amount of power consumption required for important loads that will receive power during a power outage, among the loads that receive power from the power grid, and setting a lower limit value of the charge amount of the storage battery based on the predicted power consumption amount and outputting the lower limit value to an external system; obtaining, from the external system, a command relating to a charge / discharge operation of the storage battery, the command being set within a range not below the lower limit of the charge amount; Executing a charging / discharging operation of the storage battery based on the acquired command. A battery storage system characterized by the above.

11. An external system that controls a storage battery system including a storage battery that can charge or discharge power, acquiring from the storage battery system a lower limit value of the charge amount of the storage battery that is set based on the amount of power consumption required by important loads that are supplied with power during a power outage, among loads that are supplied with power from the power grid; Obtaining a supply command for balancing power, which is the electricity used to adjust supply and demand, from the market system, Based on the supply command, outputting a command to the battery system to execute a charge / discharge operation of the storage battery within a range not falling below the lower limit value of the charge amount. An external system characterized by:

Images