Control device and power storage device

Abstract

To provide a power storage device distributed arrangement system capable of systematically adjusting the supply and demand of power.SOLUTION: A control device according to an embodiment is a device that sets a target value related to the exchange of power with a feeder line and performs overall control of a plurality of power storage devices that charge and discharge the storage batteries based on the target value, and has: a function of receiving first control information related to charging and discharging of a power storage device distributed arrangement system that includes a plurality of power storage devices that are arranged in a distributed manner, based on a power supply and demand plan for a system that converts power supplied from a commercial power system and supplies power to the feeder line; and a function of generating and transmitting second control information related to the charging and discharging of the power storage devices to at least one of the plurality of power storage devices based on the first control information.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a control device and a power storage device. [Background technology]

[0002] In order to provide a stable supply of electricity, it is essential to secure the supply and demand balancing capacity to control frequency and adjust the supply and demand balance in the power supply area. Supply and demand balancing capacity is the power supply capacity to match supply (generation) with the ever-changing power demand (consumption). In recent years, a supply and demand balancing market has been established that enables trading of supply and demand balancing capacity. Various methods have been proposed to provide supply and demand balancing capacity in accordance with the power supply and demand plan required in the supply and demand balancing market.

[0003] With the spread of distributed power sources such as solar and wind power generation, VPPs (Virtual Power Plants) are attracting attention as a method for providing supply and demand adjustment capabilities. VPPs provide supply and demand adjustment capabilities by integrating and controlling distributed power sources, including renewable energy facilities and storage batteries, and systematically adjusting stored energy. VPPs are applicable to a wide range of fields, and their application to the electric railway field has also been proposed.

[0004] A DC power feeding system is known as one method for supplying power to railway vehicles in electric railways. To prevent regeneration failure or overhead line voltage drops, DC power feeding systems are sometimes connected to electric railway substation equipment that includes storage batteries or storage elements (hereinafter simply referred to as "storage batteries"). Charging and discharging the storage batteries improves the regeneration rate and stabilizes the overhead line voltage.

[0005] Regarding the adjustment of power supply and demand in the electric railway field, attempts have been reported to reduce peak power demand by supplying power from secondary batteries connected to the feeder line. The secondary batteries are connected to the overhead line directly or via a converter such as a chopper, and charge and discharge in response to drops or increases in the overhead line voltage. Attempts have also been reported to connect storage batteries to the feeder line via a converter, increasing the sending voltage and discharging the storage batteries. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5187624 [Non-patent literature]

[0007] [Non-Patent Document 1] Masayuki Nogi et al., "Development of a Series Compensated Regenerative Energy Storage System and Field Test Results," Institute of Electrical Engineers of Japan 2019 National Convention, March 1, 2019 Summary of the Invention [Problem to be solved by the invention]

[0008] However, simply charging and discharging a storage battery in response to a drop or rise in feeder voltage does not provide a system that systematically adjusts power supply and demand. Furthermore, when a storage battery is connected to a feeder line without a power converter, it is not possible to control the battery's charging and discharging power or stored energy. The charging and discharging characteristics of a storage battery connected to a feeder line without a power converter are uniquely determined by the difference between the battery voltage and the output voltage of the feeding rectifier. Therefore, it is difficult to provide a system that systematically adjusts power supply and demand and stabilizes an AC power distribution system.

[0009] Furthermore, because the discharge of the storage battery is affected by the load, a drop in discharge power (sag) occurs in the power supply circuit with large load fluctuations, making it difficult to achieve continuous discharge operation.

[0010] The embodiments of the present invention have been made in consideration of the above circumstances, and have an object to provide a distributed power storage system that is capable of systematically adjusting the supply and demand of power. [Means for solving the problem]

[0011] The control device according to the embodiment is a device that sets target values ​​for the exchange of power with a feeder line and performs overall control of a plurality of power storage devices that charge and discharge storage batteries based on the target values, and has the following functions: receiving first control information regarding the charging and discharging of a distributed power storage device system that includes a plurality of the distributed power storage devices, based on a power supply and demand plan for a system that converts power supplied from a commercial power system and supplies it to the feeder line; and generating and transmitting second control information regarding the charging and discharging of the power storage device to at least one of the plurality of power storage devices, based on the first control information. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram schematically illustrating an example of the configuration of a distributed power storage device system according to the first embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of charge / discharge control according to the feeding voltage in the distributed power storage device system according to the first embodiment. [Figure 3] FIG. 3 is a diagram showing the relationship between the charging rate and the charge / discharge start voltage for adjusting the SOC within a certain range in the distributed power storage device system according to the first embodiment. [Figure 4] FIG. 4 is a diagram showing an example of control for changing the SOC by changing the discharge characteristics in the distributed power storage device system according to the first embodiment. [Figure 5] FIG. 5 is a diagram showing an example of control for changing the SOC by changing the charging characteristics in the distributed power storage device system according to the first embodiment. [Figure 6] FIG. 6 is a diagram schematically illustrating a modified example of the distributed power storage device system according to the first embodiment. [Figure 7] FIG. 7 is a diagram schematically illustrating a first configuration example of the distributed power storage device system according to the second embodiment. [Figure 8] FIG. 8 is a diagram illustrating an example of generating a power command value in the power storage device distributed arrangement system according to the second embodiment. [Figure 9]FIG. 9 is a diagram schematically illustrating a second configuration example of the power storage device distributed arrangement system according to the second embodiment. [Figure 10] FIG. 10 is a diagram schematically illustrating a modified example of the distributed power storage device system according to the second embodiment. [Figure 11] FIG. 11 is a diagram schematically illustrating an example of the configuration of a distributed power storage device system according to the third embodiment. [Figure 12] FIG. 12 is a diagram showing a modified example of the power storage device in the power storage device distributed arrangement system according to the third embodiment. [Figure 13] FIG. 13 is a diagram schematically illustrating an example of the configuration of a distributed power storage device system according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Hereinafter, elements that are identical or similar to elements already described will be designated by the same or similar reference numerals, and duplicate descriptions will generally be omitted. For example, when there are multiple identical or similar elements, a common reference numeral may be used to describe each element without distinguishing between them, or a subnumber may be used in addition to the common reference numeral to describe each element distinctly.

[0014] (First embodiment) (1-1) Configuration and operation examples FIG. 1 is a diagram schematically illustrating an example of the configuration of a power storage device distributed arrangement system according to a first embodiment. The power storage device distributed arrangement system 100 according to the first embodiment is used together with a DC power feeding system that supplies power to vehicles such as electric railways or monorails (hereinafter referred to as "electric vehicles"). The DC power feeding system includes an AC grid 11, a substation 4, a feeder 8, an electric vehicle 5, and a return line 9. The power storage device distributed arrangement system 100 includes a plurality of power storage devices 20 that are distributed relative to the DC power feeding system, and a higher-level control device 6.

[0015] The AC system 11 is a commercial power system that supplies three-phase AC power to the substation 4 . The substations 4 are power feeding substations and are arranged at intervals of, for example, 5 to 10 km. The substations 4 receive three-phase AC power from the AC system 11, convert the three-phase AC power into DC power (for example, 1,650 V) via a transformer and a rectifier (not shown), and feed the power to the feeder lines 8.

[0016] The feeder 8 supplies power to the electric car 5 . The electric vehicle 5 is a vehicle, such as a train, that can run by receiving power output from the substation 4 via the feeder line 8. The return line 9 is a conductor through which a return current flows, and is, for example, a rail on which the electric vehicle 5 runs. The circuit in which the power supplied from the substation 4 passes through the feeder line 8, is consumed by the electric vehicle 5 (load), and returns to the substation 4 again via the return line 9 is also called a feeder circuit.

[0017] The plurality of power storage devices 20 are distributed at arbitrary intervals and are each connected to a feeder line 8 and a return line 9. Each power storage device 20 includes a storage battery 1, a power converter 2, and a control unit 3.

[0018] The storage battery 1 is connected to a power converter 2 and can be charged and discharged between the power converter 2 and a feeder line 8. The storage battery 1 is an energy storage module equipped with a cell monitoring unit (CMU) and an assembled battery including multiple rechargeable battery cells, such as lithium-ion batteries, nickel-metal hydride batteries, or lead-acid batteries. The assembled battery includes, for example, 24 20 Ah storage battery cells, each connected in two parallel configurations and 12 in series. The CMU measures the voltage and temperature of each storage battery cell and notifies the control unit 3 of the measurement results via a communication protocol such as a Controller Area Network (CAN). The CMU also receives commands from the control unit 3 and performs cell balancing to achieve the voltage specified by the control unit 3. Cell balancing refers to adjusting the voltage by discharging cells with higher voltages. The storage battery 1 may be replaced with other energy storage devices or systems, such as an electric double-layer capacitor, a flywheel, or a hydroelectric power generation device.

[0019] The power converter 2 is connected between the storage battery 1 and the feeder line 8 and between the storage battery 1 and the return line 9. The power converter 2 exchanges power between the storage battery 1 and the feeder line 8 and controls charging and discharging between the storage battery 1 and the feeding circuit. For example, when the power converter 2 connects the storage battery 1 to a DC feeding circuit, it includes a DC / DC converter. However, the power converter 2 may be any converter depending on the type of energy storage medium and the feeding circuit. The power converter 2 also includes a current limiter that controls the limit value of the charging and discharging current.

[0020] The control unit 3 controls the operation of the power storage device 20. The control unit 3 issues commands to the power converter 2 regarding charging and discharging of the storage battery 1. The control unit 3 includes, for example, a processor such as a CPU (Central Processing Unit) and a memory. The control unit 3 executes programs to realize various functions. Some of the functions of the control unit 3 may be realized by an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), an FPGA (Field Programmable Gate Array), or the like. The control unit 3 may include a battery management unit (BMU). The control unit 3 sets a target value related to the balance between supply and demand of power in the feeder line 8, and outputs commands to the power converter 2 regarding charging and discharging of the storage battery 1 based on the target value.

[0021] More specifically, the control unit 3 monitors the cell voltage and temperature of the storage battery 1 and calculates the state of charge (SOC) of the storage battery 1. The control unit 3 also monitors the voltage of the feeder line 8, for example, via the power converter 2. The control unit 3 sets a target value related to the exchange of power between the feeder line 8 and the power storage device distributed system 100, calculates a power command value related to the charging and discharging of the storage battery 1 based on the set target value, and outputs the power command value to the power converter 2.

[0022] The control unit 3 is also capable of bidirectional communication with the upper control device 6 via a transmission line 7. The transmission line 7 is constructed as a bidirectional double ring transmission line, for example, a token ring using a twisted pair cable, so that communication can continue even if one line is broken. Other transmission methods may also be used for communication between the control unit 3 and the upper control device 6.

[0023] The upper control device 6 performs integrated control of the operation of the multiple distributed power storage devices 20. The upper control device 6 transmits information bidirectionally to and from each power storage device 20 via a transmission path 7. The upper control device 6 also includes a processor and a memory, and executes programs to realize various functions. Some of the functions of the upper control device 6 may also be realized by an ASIC, PLD, FPGA, or the like. The upper control device 6 manages the power value required for the entire power storage device distributed system 100 as a target power value and assigns the target power value to the multiple power storage devices 20 (e.g., three power storage devices 20 in FIG. 1 ). The target power value may be received from a control device higher than the upper control device 6, or may be input to the upper control device 6 manually. The upper control device 6 generates control information including a power command value for charging and discharging each storage battery 1 based on the target power value assigned to each power storage device 20, and transmits the control information to the control unit 3 of each power storage device 20.

[0024] The distributed power storage device system 100 controls the adjustment of power supply and demand based on a power supply and demand plan established between the power storage device distributed system 100 and a power supply system including a feeder line 8 and a commercial power grid. The supply and demand plan includes information such as charging or discharging at a certain time on a certain day, and may also be referred to as a power generation plan, a demand plan, or a supply plan. The established supply and demand plan is stored in the upper-level control device 6. The upper-level control device 6 generates control information (first control information) related to the charging and discharging of the rechargeable battery 1 based on the supply and demand plan and transmits the control information to each of the multiple power storage devices 20. In this way, the upper-level control device 6 performs overall control based on a target power value or target SOC to be managed for the entire distributed power storage device system 100. Since energy can be obtained by integrating power over time, controlling power effectively controls energy. Tracking the target power ultimately leads to achieving the target SOC. The supply and demand plan may also be referred to as information on when and how to change the discharge start voltage or charge start voltage. The supply and demand plan may be stored in each power storage device 20 in addition to the upper control device 6. The upper control device 6 may generate control information so that each power storage device 20 achieves the assigned target power value, or may generate control information so that each power storage device 20 maintains the storage battery 1 at a desired SOC state.

[0025] The control unit 3 of each power storage device 20 sets a target value for power transfer based on control information received from the upper control device 6. The control unit 3 may set a power command value, SOC value, or the like included in the control information received from the upper control device 6 as the target value, or may calculate the target value based on the value included in the control information. The target value may include, for example, at least one of a first voltage value representing a constant target voltage at which the voltage of the feeder 8 should be maintained, a charge start voltage as a second voltage value representing the target voltage of the feeder 8 at which charging of the storage battery 1 should start, a discharge start voltage as a third voltage value representing the target voltage of the feeder 8 at which discharging from the storage battery 1 should start, a charge / discharge power command value as a power value representing the target charge / discharge power of the storage battery 1, a first current value representing a charge current limit value that limits the charge current to the storage battery 1, or a second current value representing a discharge current limit value that limits the discharge current from the storage battery 1. The control unit 3 generates a command value for charging / discharging the storage battery based on the set target value and outputs it to the power converter 2.

[0026] The upper control device 6 may transmit the charge / discharge starting voltage or the charge / discharge current limit value as control information to the control unit 3 of each storage device 20. The storage batteries 1 of the multiple storage devices 20 distributed in the power feeding system charge when the overhead line voltage rises and discharge when the overhead line voltage drops. In such a power feeding system, when voltage control is performed so that the discharge voltage of the storage device 20 to the feeding circuit reaches a target voltage (e.g., 1,650 V), the power converter 2 raises the sending voltage within a range that does not cause problems such as protecting the vehicle or the substation, and then controls (current control) to limit the discharge current so that the discharge current does not exceed a certain value, thereby equivalently enabling discharge of the target power. Similarly, in the case of charging, the voltage is lowered and the charging current is limited so that the charging current does not exceed a certain value, thereby enabling charging of the target power. The control unit 3 can set the charge / discharge starting voltage or the charge / discharge current limit value included in the control information received from the upper control device 6 as the target value.

[0027] The control unit 3 of each power storage device 20 feeds back to the upper control device 6 the command value that it actually sent to the power converter 2. The timing or time interval of the feedback may be set arbitrarily. The control unit 3 may also send other information to the upper control device 6, including the temperature of the storage battery 1, the SOC of the storage battery 1, and the value of power charged and discharged between the storage battery 1 and the feeder 8. The upper control device 6 receives the command value that the control unit 3 outputs to the power converter 2 as feedback from at least one of the multiple distributed power storage devices 20, and can generate next control information (second control information) regarding charging and discharging of the storage battery 1 based on the received command value and the set supply and demand plan, and transmit the next control information to the multiple power storage devices 20.

[0028] As an example, the upper control device 6 calculates the deviation (difference) between the feedback received from the plurality of distributed power storage devices 20 and the target power value or target SOC, generates the next control information to reduce the deviation, and transmits it to each power storage device 20. For example, the upper control device 6 first calculates the target power value W for the entire distributed power storage device system 100 based on the supply and demand plan. T is determined, and the target power value W T are distributed to N power storage devices 20 under monitoring (W 11 ,W 12 ,...W 1N ) (where W T =W 11 +W 12 +...+W 1N ) Target power value W T The upper control device 6 determines the power value (W 11 ,W 12 ,...W 1N ) respectively including first control information (CS 11 ,CS 12 ,...CS 1N ) and transmits it to each of the N power storage devices 20. The upper control device 6, which has received feedback from the N power storage devices 20, calculates the power command value output from the control unit 3 to the power converter 2 in each power storage device 20 or the power value (WO 11 ,WO 12 ,...WO1N ) total (WO1=WO 11 +WO 12 +...+WO 1N )) and the target power value W T The difference between (ΔW1=W T The upper control device 6 allocates this difference equally to each of the power storage devices 20, for example, and updates the command value to be included in the next control information (second control information) (W 21 ,W 22 ,...W 2N ) (where W 21 =W 11 +ΔW1 / N,W 22 =W 12 +ΔW1 / N,...W 2N =W 1N +ΔW1 / N). The difference may be allocated unevenly. The upper control device 6 updates the updated command value (W 21 ,W 22 ,...W 2N ) respectively including second control information (CS 21 ,CS 22 ,...CS 2N ) and transmits it to each of the N power storage devices 20. The feedback is not limited to the above example, and may be reflected in a wide variety of ways.

[0029] The control information transmitted from the upper controller 6 to each controller 3 may include a command to equalize the loads of the multiple power storage devices 20 under the supervision of the upper controller 6 or the SOC of each storage battery 1. The control information transmitted from the upper controller 6 to each controller 3 may include a command to change the charge or discharge characteristics of each storage battery 1 relative to its SOC. Each controller 3 sets a target value and generates a command to the power converter 2 based on the control information received from the upper controller 6. The time interval between the commands output from each controller 3 to each power converter 2 is, for example, 25 to 100 milliseconds or 1 second. The distributed power storage device system 100 can achieve the supply and demand adjustment required for the entire distributed power storage device system 100 according to a supply and demand plan by cooperation between the upper controller 6 and the controllers 3 of the multiple distributed power storage devices 20.

[0030] The number of power storage devices 20 included in the power storage device distributed arrangement system 100 is not limited to the example shown in the figure. The upper control device 6 can centrally control any number of power storage devices 20. Similarly, the number and arrangement of the substations 4, electric cars 5, etc. used with the power storage device distributed arrangement system 100 are also merely an example. The power storage devices 20 may be arranged near the substations 4, may be arranged in pairs with the substations 4, or may be arranged independently of the substations 4. Batteries may be arranged instead of the substations 4.

[0031] A control example in the power storage device distributed arrangement system 100 according to the first embodiment will be further described. FIG. 2 is a diagram showing an example of charge / discharge control according to the feeder line voltage in the distributed power storage device system 100 according to the first embodiment. The horizontal axis represents the feeder line voltage, and the vertical axis represents the charge current or the discharge current. c1 represents the charging start voltage, and V d1 represents the discharge start voltage. The control unit 3 generates charge / discharge commands using a table showing the relationship between the feeder line voltage and the charge / discharge current as shown in Fig. 2, and outputs the commands to the power converter 2, thereby controlling the charge / discharge of the storage battery 1. According to Fig. 2, when the feeder line voltage is equal to or greater than the charge start voltage V c1 When the voltage of the feeder line becomes higher than the discharge start voltage V, the charging current increases. However, a limit value (maximum charging current) is set for the charging current. On the other hand, when the voltage of the feeder line becomes higher than the discharge start voltage V d1 When the feeder voltage becomes lower than the discharge start voltage V, the discharge current increases. However, a limit value (maximum discharge current) is also set for the discharge current. d1 Above, the charging start voltage V c1 The storage battery 1 does not charge or discharge in the following cases:

[0032] Here, in each of the plurality of distributed power storage devices 20, the control unit 3 can control charging and discharging so that the voltage at the feeder interconnection point becomes a constant voltage. Alternatively, in each of the plurality of distributed power storage devices 20, the control unit 3 may perform control so as to decrease the voltage sent by the power converter 2 to the feeder line 8 (output voltage to the feeder circuit) in response to an increase in the discharge current from the storage battery 1, or may perform control so as to increase the voltage sent by the power converter 2 to the feeder line 8 (output voltage to the feeder circuit) in response to an increase in the charging current to the storage battery 1.

[0033] Furthermore, the control unit 3 of each power storage device 20 may perform control to reduce the voltage sent to the feeder line 8 in accordance with a decrease in the SOC of the storage battery 1. By performing control to reduce the discharge voltage in each power storage device 20 as the SOC of the storage battery 1 decreases, when viewed as a whole in the distributed power storage device system 100, a power storage device 20 with a high SOC of the storage battery 1 will bear more discharge power than a power storage device 20 with a low SOC of the storage battery 1. This makes it possible to equalize the load sharing among the multiple power storage devices 20 in the distributed power storage device system 100.

[0034] The control unit 3 of each power storage device 20 can control charging and discharging so that each storage battery 1 maintains a predetermined SOC. This is achieved, for example, by the upper control device 6 setting a target SOC value and transmitting it to the control unit 3 of each power storage device 20, and the control unit 3 of each power storage device 20 controlling the storage battery 1 to perform adjusted charging and discharging when the SOC of the storage battery 1 deviates from the target value. Alternatively, the upper control device 6 may not set a clear target SOC value, and the control unit 3 of each power storage device 20 may execute control to adjust the discharge start voltage or charge start voltage in response to a decrease in the SOC of the storage battery 1. The SOC target value may also be a value received from a control device higher than the upper control device 6, or may be a value input to the upper control device 6 by a human system.

[0035] FIG. 3 is a diagram showing the relationship between the state of charge (SOC) and the charge / discharge start voltage for adjusting the SOC of the storage battery 1 within a certain range in the distributed energy storage system 100 according to the first embodiment. The horizontal axis represents the SOC, and the vertical axis represents the discharge start voltage or the charge start voltage. When the SOC decreases, the discharge start voltage or the charge start voltage also decreases. The control unit 3 generates charge / discharge commands using a table showing the relationship between the SOC and the charge / discharge start voltage as shown in FIG. 3 and outputs the commands to the power converter 2, thereby controlling the charging and discharging of the storage battery 1.

[0036] When the control unit 3 of each power storage device 20 is performing the above-described control, the upper control device 6 further outputs a charge or discharge command to each power storage device 20. The charge or discharge command includes, for example, a command to change the charge or discharge characteristics relative to the charging rate. Such a command may be sent from a control device higher up the upper control device 6, or may be input manually to the upper control device 6 to cause the charge or discharge command to be output.

[0037] FIG. 4 is a diagram showing an example of control for changing the SOC by changing the discharge characteristics of the storage battery 1 in the distributed energy storage device system 100 according to the first embodiment. The horizontal axis represents the state of charge (SOC), and the vertical axis represents the discharge start voltage. Generally, the higher the SOC, the higher the voltage at which each energy storage device 20 starts discharging. The control unit 3 can adjust the supply and demand of power by changing the discharge characteristics as indicated by the arrow P. That is, in each energy storage device 20, the storage battery 1 normally operates in the A1 region, but operates in the B1 region in response to a command from the control unit 3. This causes the storage battery 1 to start discharging at a high voltage in most SOC ranges. As a result, energy equivalent to the SOC difference (A1 - B1) is supplied from the storage battery 1 of each energy storage device 20 to the power feeding circuit. When the SOC decreases, the supply voltage decreases, and discharging stops. At this time, the maximum power value supplied from the storage battery 1 to the power feeding circuit is equal to the maximum discharge start voltage V max and the output current limit value I of power converter 2 limitIn this way, supply and demand can be adjusted by changing the command value of the discharge start voltage for charge and discharge control. When it is desired to adjust the discharge power, the output current limit value I limit Just change the following.

[0038] The control unit 3 holds a table specifying the correspondence relationship between the SOC and the discharge start voltage, for example, as shown in Fig. 4, and can switch the discharge characteristics to be used in response to a command from the upper control device 6. Based on the specified discharge characteristics, the control unit 3 sets the discharge start voltage as a target value and generates a command to the power converter 2.

[0039] A similar scheme can be applied to charging. FIG. 5 is a diagram showing an example of control for changing the SOC by changing the charging characteristics of the storage battery 1 in the distributed energy storage device system 100 according to the first embodiment. The horizontal axis represents the state of charge (SOC), and the vertical axis represents the charging start voltage. Generally, the lower the SOC, the lower the voltage at which each energy storage device 20 starts charging. The control unit 3 can adjust the supply and demand of power by changing the charging characteristics as indicated by the arrow Q. That is, in each energy storage device 20, the storage battery 1 normally operates in the B2 region, but operates in the A2 region in response to a command from the control unit 3. This causes the storage battery 1 to start charging at a low voltage in most SOC sections. As a result, energy equivalent to the SOC difference (A2 - B2) is stored from the power feeding circuit in the storage battery 1 of each energy storage device 20. The maximum value of the charging power stored in each storage battery 1 from the power feeding circuit is the charging start voltage V min and the current limit value I of power converter 2 limit When you want to adjust the charging power, you can set the current limit value I limit Just change the following.

[0040] The control unit 3 holds a table specifying the correspondence relationship between the SOC and the charge start voltage, for example, as shown in Fig. 5, and can switch the charge characteristics to be used in response to a command from the upper control device 6. Based on the specified charge characteristics, the control unit 3 sets the charge start voltage as a target value and generates a command to the power converter 2.

[0041] The upper control device 6 may instruct each control unit 3 to switch the charge / discharge characteristics by transmitting a table specifying the charge / discharge characteristics as shown in Fig. 4 or 5 to each control unit 3. Each control unit 3 may have multiple tables and switch between them in response to a command from the upper control device 6.

[0042] The AC system 11 of the feeding circuit in FIG. 1 may be a single power system, or may be separated into a plurality of power systems.

[0043] (1-2) Effects When a power storage device is installed independently of a power feeding system, as in the past, or when a centralized power storage device is installed, the power discharging is affected by the impedance of the power feeding circuit from the power storage device to the load (electric vehicle). Discharge from the storage battery of the power storage device to the power feeding circuit increases the voltage at the connection point of the power feeding circuit to which the power storage device is connected. Therefore, the discharge current is suppressed and the discharge power decreases at the maximum voltage level at which continuous operation is possible before protective operation is triggered (the limit voltage level before overvoltage occurs). Meanwhile, during charging, the storage battery of the power storage device is charged via a substation. Figure 1 shows a parallel power feeding circuit capable of supplying power from substations 4 on both sides to electric vehicles 5. However, if one power storage device 20 is charged with a large amount of power, the discharge power of the nearest substation 4 increases, significantly reducing the power feeding voltage and significantly reducing the load output of the substation 4.

[0044] According to the distributed power storage device system 100 of the first embodiment, multiple power storage devices 20 are distributed in a power feeding system. This distributed arrangement reduces the impedance of the power feeding circuit from the power storage devices 20 to the load of the electric vehicle 5. As a result, power can be supplied to loads located farther away than before. Furthermore, a wider range of loads can be accommodated, enabling high-output discharge operations in supply and demand adjustment of the power storage devices 20. Even if a current sag occurs in one of the power storage devices 20, the other power storage devices 20 can compensate for that shortfall. Therefore, the distributed power storage device system 100 as a whole can contribute to planned and stable power supply and demand adjustment. Similarly, charging 500 kW across three power storage devices 20 reduces the load on the control equipment compared to charging 500 kW with one power storage device 20. Therefore, planned charging of the distributed power storage devices 20 enables stable power supply and demand adjustment.

[0045] Furthermore, by controlling multiple storage devices 20 distributed within the power supply system, the supply and demand adjustment capabilities (power or amount of power) of the storage devices 20 can be integrated and operated, resulting in the realization of a larger storage system plant.

[0046] The host controller 6 monitors the entire distributed power storage system 100 and sends commands to each power storage device 20 to perform cooperative control. The commands sent from the host controller 6 to the control unit 3 of each power storage device 20 include, for example, a target power value assigned to each power storage device 20. Each control unit 3 can obtain a target voltage for the feeder line by, for example, dividing the target power value by the current of a limiter. Each control unit 3 controls charging and discharging while comparing the voltage of the feeder line 8 with the target voltage. Each control unit 3 also returns information related to actual charging and discharging to the host controller 6, for example, information indicating whether voltage control corresponding to the target power instructed by the host controller 6 was successfully executed. The host controller 6 collects information related to actual charging and discharging from the control unit 3 of each power storage device 20 and sends commands to the control unit 3 so that power supply and demand can be systematically adjusted throughout the entire distributed power storage system 100.

[0047] The upper control device 6 may transmit a power command value to the control unit 3 of each power storage device 20, and the control unit 3 may calculate a current limit value by dividing the received power command value by the voltage during charging / discharging, and the control unit 3 may transmit the current limit value to the power converter 2. This allows the control unit 3 of each power storage device 20 to control discharging or charging in response to a command from the upper control device 6, thereby changing the SOC of the storage battery 1 and enabling supply and demand adjustment across the entire distributed power storage device system 100. Alternatively, the control unit 3 of each power storage device 20 may previously store information such as a target power value, a discharging start voltage, a charging start voltage, or a current limit value.

[0048] In this way, the distributed power storage device system 100 according to the first embodiment operates as follows: when there is a power shortage, stored energy is supplied (discharged), and when there is a power surplus, power is stored (charged). Therefore, the distributed power storage device system 100 can systematically adjust the supply and demand of power as a whole system.

[0049] (1-3) Variations Fig. 6 is a diagram schematically illustrating a modified example of the power storage device distributed arrangement system according to the first embodiment. Fig. 6 is the same as Fig. 1 except that the AC system 11 is separated in the power feeding system. The power storage device distributed arrangement system 110 has the same configuration as the power storage device distributed arrangement system 100 and operates in the same manner, so a detailed description will be omitted. In other words, the power storage device distributed arrangement system 100 according to the first embodiment can also be applied to a case where the substations 4 are fed with power from different, separated AC systems 11.

[0050] (Second embodiment) (2-1) Configuration and operation examples The power storage device distributed arrangement system according to the second embodiment has the same configuration as the power storage device distributed arrangement system 100 according to the first embodiment, except that each power storage device distributed to the power feeding system performs self-end control. The following mainly describes the differences from the first embodiment.

[0051] 7 is a diagram schematically illustrating a first configuration example of a power storage device distributed arrangement system according to the second embodiment. As in the first embodiment, a power storage device distributed arrangement system 200 according to the second embodiment is used together with a DC feeding system. The DC feeding system includes an AC system 11, a substation 4, a feeder line 8, an electric car 5, and a return line 9. These are the same as the AC system 11, the substation 4, the feeder line 8, the electric car 5, and the return line 9 of the DC feeding system described in relation to the first embodiment, and therefore description thereof will be omitted.

[0052] The distributed power storage device system 200 includes a plurality of power storage devices 21 that are distributed in relation to the power feeding system. Similar to the storage device 20 described in the first embodiment, the multiple storage devices 21 are distributed at arbitrary intervals in the power feeding system and are each connected to a feeder line 8 and a return line 9. Each storage device 21 includes a storage battery 1, a power converter 2, a control unit 31, and a voltage detection unit 10. The storage battery 1 and the power converter 2 are similar to the storage battery 1 and the power converter 2 of the storage device 20 described in the first embodiment, and therefore will not be described again.

[0053] The voltage detection unit 10 detects the voltage of the AC system 11 and passes the detected voltage to the control unit 31. The control unit 31 measures the frequency of the AC system 11 based on the voltage detected by the voltage detection unit 10. The control unit 31 generates a charge / discharge power command value according to the difference between the measured frequency and a reference system frequency (also referred to as a "reference frequency") serving as a target value, and outputs the power command value to the power converter 2.

[0054] When the balance between supply and demand of electric power is disrupted, frequency fluctuations occur, making the power supply unstable. 11 and the reference grid frequency F r (50Hz or 60Hz) and the difference ΔF (ΔF = F 11 -F r) and generates a command value according to the difference ΔF to respond to load fluctuations. For example, the control unit 31 can generate a command value to reduce the difference ΔF. The reference grid frequency is an example of a target value related to power exchange between the feeder 8 and the power storage device distributed arrangement system 200. Each control unit 3 acquires the reference grid frequency in advance and sets it as the target value. Note that a known method may be used to calculate the frequency based on the AC voltage.

[0055] 8 is a diagram showing an example of generating a power command value in the power storage device distributed arrangement system 200 according to the second embodiment. The voltage detection unit 10 detects the voltage of the AC system 11 and passes it to the frequency detection unit 35. The frequency detection unit 35 is provided as one function of the control unit 31. The control unit 31 converts the frequency F detected by the frequency detection unit 35 into a power command value. 11 and the reference grid frequency F r Instead of the difference ΔF, the power command value is calculated based on the frequency deviation (ΔF / F r ) may be used. The control unit 31 can generate the power command value using, for example, a table that specifies the correspondence between the difference ΔF and the power command value. An example of such a table is a power command table 61 shown in FIG. 8. In FIG. 8, the power command table 61 specifies a discharge power command value (positive) whose value increases linearly according to the absolute value of the difference ΔF when ΔF is less than a predetermined first value ΔFa, specifies a power command value of zero when ΔF is equal to or greater than the first value ΔFa and less than a second value ΔFb, and specifies a charge power command value (negative) whose value increases linearly according to the absolute value of the difference ΔF when ΔF is equal to or greater than the second value ΔFb. The power command table 61 is merely an example, and other tables may be used. The control unit 31 may calculate the command value using, for example, a relational expression that outputs a power command value according to the difference ΔF or the frequency deviation.

[0056] In this way, in the distributed energy storage device system 200 according to the second embodiment, each distributed energy storage device 21 performs self-end control to suppress frequency fluctuations, thereby enabling the supply and demand of electricity to be adjusted across the entire distributed energy storage device system 200.

[0057] The local-end control system according to the second embodiment may also use commands from the higher-level control device 6. 9 is a diagram schematically illustrating a second configuration example of the power storage device distributed arrangement system according to the second embodiment. In the second configuration example, the power storage device distributed arrangement system 210 is also used together with a DC feeding system. The DC feeding system includes an AC grid 11, a substation 4, a feeder line 8, an electric car 5, and a return line 9. The feeding system is the same as in the first configuration example, so a description thereof will be omitted. The power storage device distributed arrangement system 210 according to the second configuration example includes a plurality of power storage devices 22 distributed with respect to the feeding system, and a higher-level control device 6.

[0058] Each power storage device 22 includes a storage battery 1, a power converter 2, a control unit 32, and a voltage detection unit 10. The storage battery 1, the power converter 2, and the voltage detection unit 10 are similar to the storage battery 1, the power converter 2, and the voltage detection unit 10 of the first configuration example, and therefore detailed description thereof will be omitted. The upper control device 6 is similar to the upper control device 6 of the power storage device distributed arrangement system 100 according to the first embodiment, and therefore a detailed description thereof will be omitted.

[0059] As in the first configuration example, the control unit 32 measures the frequency of the AC system 11 based on the voltage of the AC system 11 detected by the voltage detection unit 10, generates a charge / discharge power command value according to the difference ΔF from the reference system frequency, and outputs it to the power converter 2. As in each control unit 3 of the power storage device 20 according to the first embodiment, the control unit 32 also communicates bidirectionally with the upper control device 6 via the transmission path 7, receives commands from the upper control device 6, and transmits feedback including, for example, the SOC of the storage battery 1 to the upper control device 6. The control unit 3 and the upper control device 6 generally have different response times, making this compatibility possible. Furthermore, the upper control device 6 may monitor the voltage of the AC system 11.

[0060] (2-2) Effects When a high-speed response is required for adjusting power supply and demand, each control unit 3 may not be able to respond in time if it waits for a command from the upper control device 6. As explained in the first configuration example, in the distributed power storage device system 200 according to the second embodiment, each control unit 3 of the plurality of distributed power storage devices 21 directly monitors the voltage at the end of the AC grid 11, and can perform high-speed control to suppress frequency fluctuations. This allows stable supply and demand adjustment for the entire system.

[0061] Furthermore, as explained in the second configuration example, in the distributed energy storage device system 210, each distributed energy storage device 22 can be configured to directly monitor the terminal voltage to adjust supply and demand, while also responding to commands from the upper control device 6 in parallel.

[0062] The local-end control described in relation to the second embodiment is, in principle, performed by offline control. The local-end control shown in the first configuration example of the second embodiment corresponds to primary control reserve in the supply and demand adjustment market. In contrast, control using the upper-level control device 6 is performed by online control and corresponds to secondary or tertiary control reserve in the supply and demand adjustment market. When local-end control and upper-level control are used together as in the second configuration example of the second embodiment, online control is performed at time intervals of, for example, 5 to 15 minutes, and offline control (local-end control) is performed at time intervals of, for example, 10 seconds. In the second configuration example, two-stage control can be realized, in which the upper-level control device 6 performs low-frequency, low-precision control, and the control unit 32 of each power storage device additionally performs high-frequency, precise control.

[0063] (2-3) Modifications As a modified example, the host control device may monitor the voltage of the AC system and perform integrated control of the distributed power storage device system so as to suppress frequency fluctuations. 10 is a diagram schematically illustrating a modified example of the power storage device distributed arrangement system according to the second embodiment. The power storage device distributed arrangement system 220 according to the modified example is also used together with a DC power feeding system, as in the first and second configuration examples. The power feeding system includes an AC system 11, a substation 4, a feeder line 8, an electric car 5, and a return line 9. The power feeding system is the same as in the first configuration example, so a description thereof will be omitted. The power storage device distributed arrangement system 220 includes a plurality of power storage devices 20 distributed with respect to the power feeding system, the control device 6, and a voltage detection device 40.

[0064] Each power storage device 20 includes a storage battery 1, a power converter 2, and a control unit 3. The storage battery 1, the power converter 2, and the control unit 3 are similar to the storage battery 1, the power converter 2, and the control unit 3 of the power storage device 20 described in the first embodiment, and therefore detailed description thereof will be omitted.

[0065] The voltage detection device 40 detects the voltage of the AC system 11 and passes the detected voltage to the upper control device 6. The upper control device 6 measures the frequency of the AC system 11 based on the voltage detected by the voltage detection device 40. The upper control device 6 then calculates a power command value based on the difference or frequency deviation between the frequency of the AC system 11 and a reference system frequency, for example, using a table similar to the table 61 illustrated in FIG. 8 , and transmits the power command value to the control unit 3 of each power storage device 20. Each control unit 3 sets a target value based on the received power command value and outputs a command to the power converter 2. In this way, even when the system voltage is monitored on the upper control device 6 side, similar integrated control can be performed in the distributed power storage device system 220.

[0066] (Third embodiment) (3-1) Configuration and operation examples The power storage device distributed arrangement system according to the third embodiment has the same configuration as the power storage device distributed arrangement system 100 according to the first embodiment, except that it is used together with an AC power feeding system. The following mainly describes the differences from the first embodiment.

[0067] 11 is a diagram schematically illustrating an example of the configuration of an energy storage device distributed arrangement system according to the third embodiment. The energy storage device distributed arrangement system 300 according to the third embodiment is used together with an AC feeding system. The AC feeding system includes a first AC system 11, a second AC system 12, a substation 41, a substation 42, a section 50, a feeder 8, an electric car 5, and a return line 9. The feeder 8, the electric car 5, and the return line 9 are similar to the feeder 8, the electric car 5, and the return line 9 of the DC feeding system described in relation to the first embodiment, and therefore description thereof will be omitted. The energy storage device distributed arrangement system 300 includes a plurality of energy storage devices 20 distributed with respect to the AC feeding system, and a higher-level control device 6.

[0068] The first AC system 11 and the second AC system 12 are, for example, commercial power systems having a phase difference from each other, or may be power systems having different frequencies.

[0069] The substation 41 is an AC substation that includes a circuit breaker and a transformer, converts three-phase AC power received from the first AC system 11 into single-phase AC power, and outputs the single-phase AC power to the feeding circuit. The substation 42 is an AC substation that includes a circuit breaker and a transformer, converts three-phase AC power received from the second AC system 12 into single-phase AC power, and outputs the single-phase AC power to the feeding circuit.

[0070] Section 50 is a so-called dead section, and is arranged to electrically separate the overhead lines to prevent short-circuiting of power of different electrification systems, different phases, or different frequencies. The feeder 8 is separated by section 50 between substation 41 fed by first AC system 11 and substation 42 fed by second AC system 12.

[0071] The plurality of energy storage devices 20 are distributed at arbitrary intervals and are each connected to a feeder line 8 and a return line 9. Each energy storage device 20 includes a storage battery 1, a power converter 2, and a control unit 3. The energy storage device 20 according to the third embodiment is similar to the energy storage device 20 described in the first embodiment, and therefore a detailed description thereof will be omitted. However, since the feeder line 8 employs an AC feeding system, the power converter 2 converts the DC of the storage battery 1 into AC and supplies it to the feeder line 8.

[0072] Because the substation 41 and the substation 42 are AC substations, when regeneration occurs, a reverse power flow from the substation 41 to the three-phase AC system 11 or a reverse power flow from the substation 42 to the three-phase AC system 12 may occur. For example, each power storage device 20 can monitor, via the control unit 3, a reverse power flow current from a nearby substation 41 (within the same section) to the three-phase AC system 11 (as shown by arrow R, for example), and, when a reverse power flow occurs, charge the storage battery 1 to absorb the active power. Under the control of the control unit 3, the power converter 2 converts the AC current received from the feeder 8 into DC current and charges the storage battery 1. In the third embodiment, the target value for power exchange between the feeder 8 and the distributed power storage device system 300 is, for example, a current threshold value for determining the occurrence of a reverse power flow.

[0073] (3-2) Effects In the case of an AC power feeding system, the overhead lines are separated into sections, so a substation 4 cannot send power to an electric car 5 in an adjacent section that is separated by a section. The distributed power storage device system 300 according to the third embodiment enables integrated control of charging and discharging of the storage batteries 1 of the power storage devices 20 across sections that are separated by sections, and allows adjustment of power supply and demand for the entire system.

[0074] (3-3) Modification Fig. 12 is a diagram showing a modified example of the power storage device 20 in the power storage device distributed arrangement system 300 according to the third embodiment. In Fig. 12, the power storage device 23 is installed across sections 50. The power storage device 23 includes a power converter 25 and a power converter 26 instead of the power converter 2 shown in Fig. 11. The power converter 25 is connected to, for example, the M phase (Main phase) side, and includes a DC / DC converter and a DC / AC converter. The power converter 26 is connected to, for example, the T phase (Teaser) side, and includes a DC / DC converter and a DC / AC converter.

[0075] In this modification, the control unit 3 monitors the reverse power flow in the substations (not shown) on both sides of the section 50, and controls the charging and discharging of the storage battery 1 via the power converter 25 or the power converter 26. This allows the distributed power storage device system 300 to monitor the electric power for each direction separated by the section 50, and share the electric power for each direction between the power feeding circuits.

[0076] The distributed energy storage device system 300 according to the third embodiment may include a plurality of distributed energy storage devices 20, a plurality of distributed energy storage devices 23, or a combination of one or more energy storage devices 20 and one or more energy storage devices 23 in a distributed arrangement.

[0077] (Fourth embodiment) The distributed power storage device system according to the fourth embodiment includes another power storage system (hereinafter referred to as an "auxiliary power storage device") arranged in an AC system, and performs integrated control including the auxiliary power storage device. The distributed power storage device system according to the fourth embodiment has the same configuration as the distributed power storage device system 100 according to the first embodiment, except that it includes the auxiliary power storage device. The following mainly describes the differences from the first embodiment.

[0078] (4-1) Configuration and operation examples 13 is a diagram schematically illustrating an example of the configuration of an energy storage device distributed arrangement system according to a fourth embodiment. As with the first embodiment, an energy storage device distributed arrangement system 400 according to the fourth embodiment is used together with a DC feeding system. The DC feeding system includes an AC system 11, a substation 4, a feeder line 8, an electric car 5, and a return line 9. These are the same as the AC system 11, the substation 4, the feeder line 8, the electric car 5, and the return line 9 of the DC feeding system described in relation to the first embodiment, and therefore description thereof will be omitted.

[0079] The distributed power storage device system 400 includes a plurality of power storage devices 20 distributed in a power feeding system, a host control device 6, and an auxiliary power storage device 24.

[0080] Similar to the storage devices 20 described in the first embodiment, the multiple storage devices 20 are distributed at arbitrary intervals in the power feeding system and are each connected to a feeder line 8 and a return line 9. Each storage device 20 includes a storage battery 1, a power converter 2, and a control unit 3. These storage batteries 1, power converters 2, and control units 3 are similar to the storage battery 1, power converter 2, and control unit 3 of the storage device 20 described in the first embodiment, and therefore detailed description thereof will be omitted.

[0081] The auxiliary power storage device 24 is connected to the third AC system 13. The auxiliary power storage device 24 is, for example, a power storage device that can be charged and discharged between the auxiliary power storage device 24 and a commercial power source in a station building. The AC system 11 and the third AC system 13 do not need to be distinguished from each other, and may be primarily commercial power systems of the same power company.

[0082] Similar to the distributed power storage devices 20, the auxiliary power storage device 24 includes a storage battery 1, a power converter 2, and a control unit 3. The storage battery 1, the power converter 2, and the control unit 3 have the same configurations and functions as the storage battery 1, the power converter 2, and the control unit 3 of the power storage device 20. The output of the auxiliary power storage device 24 is connected to a feeder line 8 via a transformer (not shown). The control unit 3 of the auxiliary power storage device 24 also communicates bidirectionally with the upper control device 6 via a transmission line 7.

[0083] The upper control device 6 monitors the charging and discharging status of the power storage devices 20 distributed within the power feeding system, and uses the output of the auxiliary power storage device 24 when power is insufficient. For example, when the sum of discharge power values ​​received from the multiple power storage devices 20 under monitoring is less than the discharge power value required in the supply and demand plan, the upper control device 6 can determine that there is a power shortage and instruct the control unit 3 of the auxiliary power storage device 24 to discharge the storage battery 1. Alternatively, for example, when the sum of power command values ​​actually output from the multiple power storage devices 20 under monitoring is less than the sum of the power command values ​​output from the upper control device 6 to each control unit 3, the upper control device 6 can determine that there is a power shortage and instruct the control unit 3 of the auxiliary power storage device 24 to discharge the storage battery 1. In the fourth embodiment, an example of a target value for power exchange between the feeder 8 and the distributed power storage device system 400 is a threshold value used to determine power shortage, such as the discharge power value or the sum of the power command values ​​required in the supply and demand plan.

[0084] (4-2) Effects Generally, the charge / discharge power of the energy storage devices 20 distributed within the power feeding system is limited by the load of the electric vehicles 5 running within the power feeding system. Without sufficient load within the power feeding circuit, the energy storage devices 20 cannot discharge properly, preventing the necessary supply and demand adjustment. For example, in the event of a fatal accident or a natural disaster such as an earthquake, force majeure such as a breakdown in the power feeding equipment can reduce the charge / discharge capacity of each energy storage device 20 responsible for supply and demand adjustment in the distributed power storage device system 400. In such cases, the distributed power storage device system 400 can supply the insufficient charge / discharge power from the auxiliary power storage device 24. The upper control device 6 monitors the charge / discharge status of each energy storage device 20 via the transmission line 7. If each energy storage device 20 is unable to comply with the desired command, the auxiliary power storage device 24 can be charged / discharged to supplement the supply and demand adjustment capability, enabling planned supply and demand adjustment throughout the system.

[0085] As described above in detail, in the distributed power storage device system according to the embodiment, each of the plurality of power storage devices distributed within the power feeding system includes a power converter connected to a feeder, a storage battery connected to the power converter and capable of charging and discharging between the feeder and the power storage device distributed system via the power converter, and a control unit that sets a target value for power exchange between the feeder and the distributed power storage device system, generates command values ​​for charging and discharging the storage battery based on the target value, and outputs the command value to the power converter. This makes it possible for each power storage device to charge and discharge in a more planned manner, rather than simply charging and discharging in response to increases and decreases in the voltage of the feeder or overhead line, and enables the necessary power supply and demand adjustment for the entire system.

[0086] Therefore, the distributed power storage device system according to the embodiment can perform planned adjustment of power supply and demand for the entire system by controlling the charging and discharging of the storage batteries in each of the power storage devices distributed within the power feeding system.

[0087] The present invention is not limited to the above-described embodiment. For example, in the distributed power storage device system according to each embodiment, each distributed power storage device may or may not be a unitized device. The term "power storage device" may be read as "power storage system." As an example, if an electric vehicle 5 is equipped with a power storage device or a power storage system, the power storage device, etc. may also be incorporated into the distributed power storage device system. The upper control device 6 can transmit commands via wire or wirelessly to the power storage devices, etc. of the electric vehicle 5, causing them to charge or discharge in order to adjust power supply and demand. Similarly, different types of power storage or energy storage systems may be incorporated into the distributed power storage device system according to the embodiments.

[0088] In the distributed battery system according to each embodiment, the multiple distributed power storage devices may all have the same configuration, or may have different configurations. For example, a power storage device including a storage battery 1 and a power storage device including an electric double layer capacitor instead of the storage battery 1 may be mixed in the distributed power storage device system. Furthermore, in the distributed power storage device system according to each embodiment, the upper control device 6 may be realized by multiple upper control devices operating in cooperation with each other.

[0089] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. (Appendix 1) A distributed power storage device system including a plurality of distributed power storage devices, Each of the plurality of power storage devices is a power converter connected to the feeder; a storage battery connected to the power converter and capable of being charged and discharged between the power converter and the feeder line via the power converter; a control unit that sets a target value related to power exchange between the feeder and the power storage device distributed arrangement system, generates a command value related to charging / discharging of the storage battery based on the target value, and outputs the command value to the power converter; A distributed power storage device system comprising: (Appendix 2) The target value is a first voltage value representing a target voltage at which the voltage of the feeder line should be maintained; or a second voltage value representing a target voltage of the feeder line at which charging of the storage battery should be started; a third voltage value representing a target voltage of the feeder line at which discharge from the storage battery should be started; a power value representing a target charge / discharge power of the storage battery; a first current value representing a current limit value that limits a charging current to the storage battery; or a second current value representing a current limit value that limits a discharge current from the storage battery; 2. The distributed power storage system according to claim 1, including at least one of the following: (Appendix 3) A host control device that controls the plurality of power storage devices in an integrated manner, receiving first control information related to charging and discharging of the distributed power storage device system based on a supply and demand plan established between a power feeding system including the power storage device and a commercial power system; a host control device that generates second control information related to charging and discharging of the power storage device based on the first control information and transmits the second control information to at least one of the plurality of power storage devices; 3. The distributed power storage device system according to claim 1 or 2, further comprising: (Appendix 4) The distributed power storage system according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the power storage devices are provided with charge / discharge control that equalizes the charging rates of the distributed power storage devices. (Supplementary Note 5) The distributed energy storage device system according to claim 3, wherein the first control information or the second control information includes an instruction to change a discharge characteristic or a charge characteristic with respect to a charging rate in at least one of the plurality of energy storage devices. (Appendix 6) 6. The distributed energy storage system according to any one of Supplementary Note 1 to Supplementary Note 5, wherein the plurality of energy storage devices have at least one of output voltage characteristics in which the output voltage to the power line decreases when the feeder output current increases so as to equalize the loads on the energy storage devices, or characteristics in which the output voltage decreases in response to a decrease in the charging rate of the storage batteries. (Appendix 7) The distributed energy storage device system described in Appendix 3, wherein at least one of the plurality of energy storage devices monitors, by the control unit, the power value charged and discharged between the storage battery and the feeder line, and transmits the monitored power value to the upper control device. (Appendix 8) The power storage device distributed arrangement system according to claim 7, wherein the upper control device calculates a difference between a value of power charged / discharged between the storage battery and the feeder line received from the power storage device and the supply and demand plan, and generates the second control information based on the calculated difference. (Appendix 9) Each of the plurality of power storage devices further includes a detection unit that detects a receiving voltage of the power supply line from a commercial power system, At least one of the plurality of power storage devices measures a frequency of the commercial power system based on the detected received voltage by the control unit, generates the command value so as to make a difference between the measured frequency and a reference frequency equal to or less than a predetermined value, and outputs the command value to the power converter. 9. The distributed power storage device system according to any one of Supplementary Note 1 to Supplementary Note 8. (Appendix 10) the higher-level control device detects a receiving voltage from a commercial power system to the feeder, measures a frequency of the commercial power system based on the detected receiving voltage, and generates the second control information so as to make a difference between the measured frequency and a reference frequency equal to or less than a predetermined value. 4. The distributed power storage system according to claim 3. (Appendix 11) The distributed power storage device system has a power conversion device that converts AC to DC connected to the feeder line, and an auxiliary power storage device that includes a storage battery in a power system on the AC side of the power conversion device, and the upper control device outputs a command regarding charging and discharging to the auxiliary power storage device when a total of power values ​​charged and discharged between the storage battery and the feeder line, which is received from each of the plurality of power storage devices, does not satisfy a value required in the supply and demand plan. 4. The distributed power storage system according to claim 3. [Explanation of symbols]

[0090] 1...storage battery, 2, 25, 26...power converter, 3, 31, 32...control unit, 4, 41, 42...substation, 5...electric vehicle, 6...high-level control device, 7...transmission line, 8...feeder line, 9...return line, 10...voltage detection unit, 11, 12, 13...AC system, 20, 21, 22, 23...storage device, 24...auxiliary storage device, 35...frequency detection unit, 40...voltage detection device, 50...section, 61...power command table, 100, 110, 200, 210, 220, 300, 400...distributed storage device system

Claims

1. A device that sets a target value related to power exchange with a feeder line and controls a plurality of power storage devices that charge and discharge storage batteries based on the target value, a function of receiving first control information related to charging and discharging of the distributed power storage system including the plurality of distributed power storage devices, based on a power supply and demand plan for a system that converts power supplied from a commercial power system and supplies the power to the feeder; a function of generating and transmitting second control information related to charging and discharging of the power storage device to at least one of the plurality of power storage devices based on the first control information; A control device comprising:

2. The control device according to claim 1 , further comprising a charge / discharge control that equalizes the charging rates of the plurality of distributed power storage devices.

3. The control device according to claim 1 , wherein the first control information or the second control information includes an instruction to change a discharge characteristic or a charge characteristic with respect to a charge rate in at least one of the plurality of power storage devices.

4. 2. The control device according to claim 1, wherein the function of generating and transmitting the second control information calculates a difference between a value of power charged / discharged between the storage battery and the feeder line received from at least one of the power storage devices and the supply and demand plan, and generates the second control information based on the calculated difference.

5. 2. The control device according to claim 1, wherein the function of generating and transmitting the second control information detects a receiving voltage from the commercial power system to the feeder, measures a frequency of the commercial power system based on the detected receiving voltage, and generates the second control information so that a difference between the measured frequency and a reference frequency is equal to or less than a predetermined value.

6. the distributed power storage device system includes a power conversion device that converts AC to DC connected to the feeder line, and an auxiliary power storage device including a storage battery in a power system on the AC side of the power conversion device, 2. The control device according to claim 1, further comprising a function of outputting a command regarding charging / discharging to the auxiliary power storage device when a total of power values ​​charged / discharged between the storage battery and the feeder line, which is received from each of the plurality of power storage devices, is less than a value required in the supply and demand plan.

7. a power converter connected to the feeder; a storage battery connected to the power converter and capable of being charged and discharged between the power converter and the feeder line via the power converter; a control unit that generates a command value related to charging and discharging of the storage battery based on a target value related to power exchange between the feeder line and the power storage device distributed arrangement system, and outputs the command value to the power converter, The control unit generates the command value regarding charging and discharging of the storage battery based on a power supply and demand plan for a system that converts power supplied from a commercial power system and supplies the power to the feeder line, in accordance with second control information regarding charging and discharging of the power storage device, which is generated by a higher-level control device based on first control information regarding charging and discharging of the power storage device distributed system including the power storage device.

8. The target value is a first voltage value representing a target voltage at which the voltage of the feeder line should be maintained; or a second voltage value representing a target voltage of the feeder line at which charging of the storage battery should be started; a third voltage value representing a target voltage of the feeder line at which discharge from the storage battery should be started; a power value representing a target charge / discharge power of the storage battery; a first current value representing a current limit value that limits a charging current to the storage battery; or a second current value representing a current limit value that limits the discharge current from the storage battery; The power storage device according to claim 7 , comprising at least one of:

9. The power storage device according to claim 7 , wherein the first control information or the second control information includes an instruction to change a discharge characteristic or a charge characteristic of the storage battery relative to a charging rate.

10. 8. The power storage device according to claim 7, having at least one of an output voltage characteristic in which an output voltage to the feeder line decreases when an output current of the feeder line increases, so as to equalize loads with other multiple power storage devices connected to the feeder line, or a characteristic in which an output voltage decreases in accordance with a decrease in a charging rate of the storage battery.

11. the control unit monitors a value of power charged and discharged between the storage battery and the feeder line, and transmits the monitored power value to the upper control device; The power storage device according to claim 7 , wherein the second control information is information generated based on a difference between a value including at least a value of power charged / discharged between the storage battery and the feeder line and the supply and demand plan.

12. a detection unit that detects a receiving voltage of the feeder line from the commercial power system, 8. The power storage device according to claim 7, wherein the control unit measures a frequency of the commercial power system based on the received voltage detected by the detection unit, generates the command value so as to make a difference between the measured frequency and a reference frequency equal to or less than a predetermined value, and outputs the command value to the power converter.

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