Server device, power control system, and method of operating power control system

Abstract

To enable reduction in loads on storage batteries that supply power in a community.SOLUTION: A server device has a communication unit, and a control unit that communicates with a plurality of storage batteries that discharge power consumed in a district and charge surplus power by the communication unit. The control unit derives a difference between the amount of power stored in a first storage battery during a first period and a reference, and sends an instruction to a second storage battery, which has a slower response speed than the first storage battery, to charge and discharge the difference during a second period longer than the first period.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a server device, a power control system, and a method of operating a power control system. [Background technology]

[0002] In communities managed by local governments, companies, etc., the concept of a Community EMS (Community Energy Management System, or CEMS) is being developed to manage the overall power generation by power generation facilities distributed within the community, the power supply by the power company's power grid, and the power demand generated within the community. Various technologies have been proposed for supplying power that matches the power demand within a community, and for example, Patent Document 1 discloses a system for controlling the operation of a distributed power source consisting of a generator and a storage battery. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-139907 Summary of the Invention [Problem to be solved by the invention]

[0004] There is room to reduce the load on storage batteries when supplying electricity in response to fluctuations in electricity demand.

[0005] The present disclosure relates to a server device and the like that enables load reduction on storage batteries that supply power in a community. [Means for solving the problem]

[0006] The server device of the present disclosure has a communication unit, a plurality of storage batteries that discharge power consumption in a jurisdiction and charge surplus power, and a control unit that communicates via the communication unit, and the control unit derives the difference between the amount of power stored in a first storage battery during a first period and a reference, and sends an instruction to a second storage battery that has a slower response speed than the first storage battery to charge and discharge the difference during a second period that is longer than the first period.

[0007] The power control system disclosed herein is a power control system having a plurality of storage batteries that discharge power consumed in a jurisdiction and charge surplus power, and a server device that communicates with the plurality of storage batteries, wherein the server device derives the difference between the amount of power stored in a first storage battery during a first period and a reference, and sends an instruction to a second storage battery that has a slower response speed than the first storage battery to charge and discharge the difference during a second period that is longer than the first period.

[0008] The method of operating a power control system disclosed herein is a method of operating a power control system having a plurality of storage batteries that discharge power consumption in a jurisdiction and charge surplus power, and a server device that communicates with the plurality of storage batteries, and includes a step in which the server device derives the difference between the amount of power stored in a first storage battery during a first period and a reference, and sends an instruction to a second storage battery having a slower response speed than the first storage battery to charge or discharge the difference during a second period longer than the first period. [Effects of the Invention]

[0009] The server device and the like according to the present disclosure can reduce the load on the storage battery that supplies power to the community. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a CEMS. [Figure 2] FIG. 10 is a diagram illustrating an example of an operation procedure of a CEMS server. [Figure 3] FIG. 10 is a diagram illustrating an example of the operation of a CEMS server. [Figure 4]FIG. 10 is a diagram illustrating an example of the operation of a high-response battery and a low-response battery. DETAILED DESCRIPTION OF THE INVENTION

[0011] The following describes the embodiments.

[0012] [CEMS configuration example] FIG. 1 is a diagram showing an example of the configuration of a CEMS in one embodiment. In this CEMS, a CEMS server 10 manages the supply and receipt of electricity in a community 1. Hereinafter, a community refers to any block or area managed by a local government, a company, or the like. The CEMS server 10 is communicably connected to one or more battery management servers (hereinafter referred to as BM servers) 13, power loads 14, storage batteries 15, and power generation facilities 18 via a network 11. The CEMS server 10 is also communicably connected to a grid 12 via a network 17. The BM server 13 is also communicably connected to one or more storage batteries 16. The CEMS server 10 executes information processing to instruct the power generation facilities 18 to generate electricity and to purchase electricity from the grid 12 in response to the power demand of the power loads 14 distributed within the community 1. Furthermore, the CEMS server 10 controls the storage battery 15 and causes the BM server 13 to control the storage battery 16 in order to compensate for any excess or deficiency in generated power or purchased power by charging and discharging the storage batteries 15, 16. The BM server 13 shares with the CEMS server 10 the processing load required to control the storage battery 16.

[0013] The CEMS server 10 and the BM server 13 are server computers belonging to, for example, a cloud computing system or other computing system. The networks 11 and 17 are, for example, the Internet, an ad hoc network, a LAN, a MAN (Metropolitan Area Network), or other networks, or any combination thereof. The power loads 14 are, for example, electrical appliances, lighting, air conditioning equipment, etc. installed in homes, commercial facilities, etc. The storage battery 15 is a large, stationary storage battery, such as a lithium-ion battery or a nickel-metal hydride battery, and its controller. The storage battery 16 is a portable or relatively small battery, such as a lithium-ion battery or a nickel-metal hydride battery, and its controller, installed in a mobile object or home to meet the power demand of the mobile object or home and operates more randomly than the storage battery 15. Under the control of the BM server 13, the storage batteries of the mobile object, home, etc. are used as appropriate to supply power to other power loads in the community 1. The power generation equipment 18 is, for example, a power generation device using alternative energy sources such as solar power or wind power, and its controller, or various fuel cells and their controllers.

[0014] In this embodiment, the CEMS server 10 corresponds to a "server device." The CEMS server 10 includes a communication unit 101 and a control unit 103 that communicates with a plurality of storage batteries 15, 16 that discharge power consumed in a district, i.e., a community 1, and charge surplus power via the communication unit 101. The control unit 103 calculates the difference between the amount of power stored in the first storage battery 15 during a first period and a reference, and sends an instruction to the second storage battery 16, which has a slower response speed than the first storage battery 15, to charge or discharge the difference during a second period that is longer than the short-response first period. In this CEMS, the CEMS server 10 directly controls the operation of the storage battery 15, while controlling the operation of the storage battery 16 via the BM server 13. Therefore, the storage battery 15 has a higher response speed than the storage battery 16 (hereinafter, the storage batteries 15, 16 will be referred to as the high-response battery 15 and the low-response battery 16, respectively). However, if the charge / discharge load is concentrated on the high-response battery 15, there is a risk of accelerating the deterioration of the high-response battery 15. In this regard, by operating as described above, the CEMS server 10 compensates for the difference between the reference amount of stored power in the high-response battery 15 during the first response period (hereinafter referred to as the short response period) by charging / discharging the low-response battery 16 during the second response period (hereinafter referred to as the long response period). This makes it possible to reduce the load on the high-response battery 15 that supplies power to the community 1.

[0015] [Example of CEMS Server 10 configuration] As shown in Fig. 1, the CEMS server 10 has a communication unit 101, a storage unit 102, and a control unit 103. The CEMS server 10 may be a single server computer, or may be configured from two or more computers that are communicatively connected and operate in cooperation with each other. In the case of two or more computers, the configuration shown in Fig. 2 is appropriately arranged on the two or more computers.

[0016] The communication unit 101 includes one or more communication interfaces. The communication interface is, for example, a LAN interface. The communication unit 101 receives information used in the operation of the CEMS server 10 and transmits information obtained by the operation of the CEMS server 10. The CEMS server 10 is connected to a network 11 by the communication unit 101, and communicates information with the BM server 13, power loads 14, high-response batteries 15, power generation equipment 18, etc. via the network 11.

[0017] The storage unit 102 includes, for example, one or more semiconductor memories that function as a main storage device, an auxiliary storage device, or a cache memory, one or more magnetic memories, one or more optical memories, or a combination of at least two of these. The semiconductor memory is, for example, a RAM (Random Access Memory) or a ROM (Read Only Memory). The RAM is, for example, an SRAM (Static RAM) or a DRAM (Dynamic RAM). The ROM is, for example, an EEPROM (Electrically Erasable Programmable ROM). The storage unit 102 stores information used in the operation of the CEMS server 10 and information obtained by the operation of the CEMS server 10.

[0018] The control unit 103 includes one or more processors, one or more dedicated circuits, or a combination of these. The processor is, for example, a general-purpose processor such as a CPU (Central Processing Unit), or a dedicated processor such as a GPU (Graphics Processing Unit) specialized for specific processing. The dedicated circuit is, for example, an FPGA (Field-Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit). The control unit 103 executes information processing related to the operation of the CEMS server 10 while controlling each unit of the CEMS server 10.

[0019] The functions of the CEMS server 10 are realized by executing a control program on a processor included in the control unit 103. The control program is a program that causes a computer to execute processing of steps included in the operation of the CEMS server 10, thereby causing the computer to realize functions corresponding to the processing of those steps. In other words, the control program is a program that causes a computer to function as the CEMS server 10. Some or all of the functions of the CEMS server 10 may also be realized by a dedicated circuit included in the control unit 103. The control program may also be stored in a non-transitory recording / storage medium that is readable by the CEMS server 10, and read by the CEMS server 10 from the medium.

[0020] The description of the configuration example of the CEMS server 10 also applies to the BM server 13.

[0021] [Example of operation of CEMS server 10] Fig. 2 is a flowchart illustrating the operation procedure of the CEMS server 10. The procedure shown in Fig. 2 is executed by the control unit 103, for example, for each short response period. The short response period is, for example, from several tens of seconds to several minutes. On the other hand, the long response period is, for example, from several minutes to several tens of minutes. Here, an example of the procedure of the control unit 103 when the short response period is 1 minute and the long response period is 3 minutes is shown.

[0022] In step S20, the control unit 103 acquires the remaining charge of the high-response batteries 15. It requests information on the current remaining charge from each high-response battery 15, and acquires the information sent from each high-response battery 15 in response.

[0023] In parallel with step S20, in step S21, the control unit 103 derives a control target for the high-response battery 15. For example, the control unit 103 derives a control target for the high-response battery 15 in 30-minute increments from the current time. An example of the control target is shown in FIG. 3. In FIG. 3, the vertical axis represents the amount of power stored in the high-response battery 15, and the horizontal axis represents elapsed time, and a control target 30 for the amount of power stored in the high-response battery 15 over a 30-minute period is shown. The control unit 103 estimates the amount of power discharged from the high-response battery 15 using an arbitrary algorithm, for example, using a history of power consumption in the community 1 at the same time in the past, and derives a control target 30 that gradually decreases in an approximately linear manner from the current remaining amount of power stored.

[0024] In step S22, the control unit 103 derives the adjustment capability of the high-response battery 15. The control unit 103 identifies a control target for the short response period in the control target 30 in FIG. 3 and derives the corresponding adjustment capability. The adjustment capability is a range within which deviation from the control target in both positive and negative directions is allowed. The adjustment capabilities α and β are derived by multiplying the control target by an adjustment coefficient. The absolute value of the adjustment coefficient is, for example, the standard deviation in the history of the remaining power storage capacity of the high-response battery 15 at the same time in the past.

[0025] In step S23, the control unit 103 derives a control standard for the high-response battery 15. The control standard is defined as an upper limit 31 and a lower limit 32 that are displaced by adjustment capabilities α and β with respect to the control target 30 in Fig. 3. The control unit 103 derives the control standard, i.e., the upper limit 31 and the lower limit 32, using the control target and adjustment capabilities α and β in the short response period.

[0026] In step S24, the control unit 103 determines whether the remaining amount of power stored in the high-response battery 15 is below the current lower limit. If the control unit 103 determines that the remaining amount of power stored is below the lower limit (Yes), the control unit 103 proceeds to step S25. On the other hand, if the control unit 103 determines that the remaining amount of power stored is not below the lower limit (No), the control unit 103 proceeds to step S26.

[0027] In step S25, the control unit 103 derives the discharge amounts of the high-response battery 15 and the low-response battery 16. That is, the control unit 103 derives the difference between the remaining amount of charge stored in the high-response battery 15 and the control standard. For example, the control unit 103 derives the difference by subtracting the remaining amount of charge from the current lower limit of the high-response battery 15. This difference corresponds to the discharge amount of the high-response battery 15 in the subsequent short response period and the discharge amount of the low-response battery 16 in the subsequent long response period. Specifically, the sum of the differences in the long response period corresponds to the charge amount of the low-response battery 16 in the subsequent long response period.

[0028] In step S26, the control unit 103 determines whether the remaining amount of power currently stored in the high-response battery 15 exceeds the current upper limit. If the control unit 103 determines that the remaining amount of power currently stored exceeds the upper limit (Yes), the control unit 103 proceeds to step S27. On the other hand, if the control unit 103 determines that the remaining amount of power currently stored does not exceed the upper limit (No), the control unit 103 proceeds to step S28.

[0029] In step S27, the control unit 103 derives the charge amounts of the high-response battery 15 and the low-response battery 16. That is, the control unit 103 derives the difference between the remaining charge amount of the high-response battery 15 and the control standard. For example, the control unit 103 derives the difference by subtracting an upper limit from the current charge amount of the high-response battery 15. This difference corresponds to the charge amount of the high-response battery 15 in the subsequent short response period and the charge amount of the low-response battery 16 in the subsequent long response period. Specifically, the sum of the differences in the long response period corresponds to the charge amount of the low-response battery 16 in the subsequent long response period.

[0030] In step S28, the control unit 103 derives the charge / discharge amounts of the high-response battery 15 and the low-response battery 16. In this case, the current remaining amount of power stored in the high-response battery 15 does not deviate from the control target beyond the adjustment capability, and there is no need for compensation by the low-response battery 16. Therefore, the control unit 103 derives zero as the charge / discharge amounts of the high-response battery 15 and the low-response battery 16.

[0031] In step S29, the control unit 103 sends charge / discharge instructions to the high-response battery 15 and the low-response battery 16. The control unit 103 sends instructions to the high-response battery 15 and the low-response battery 16 to charge / discharge at the charge / discharge amounts calculated in step S25, S27, or S28 during the next short response period and the next long response period, respectively. Then, the control unit 103 ends the current processing cycle.

[0032] [Example of operation of high-response battery 15 and low-response battery 16] 4 is a diagram schematically illustrating the operation of the high-response battery 15 and the low-response battery 16. Timing chart 40A shows the operation using only the high-response battery 15 as a comparative example, and timing chart 40B shows the operation using the high-response battery 15 and the low-response battery 16 in this embodiment.

[0033] Timing chart 40A has charts 41 and 42, each showing the operation of high-response battery 15 during a one-minute short response period SP and a three-minute long response period LP, with the horizontal axis representing elapsed time. Charts 41 and 42 show the difference in remaining charge from the control standard of high-response battery 15 and the amount of charge and discharge by high-response battery 15, with the upward direction of the vertical axis representing the amount of discharge and the downward direction representing the amount of charge, respectively.

[0034] Chart 41 shows, in chronological order, the difference En (n=1, 2, 3, ...) between the amount of stored power in high-response battery 15 and the upper or lower limit for each short response period SP. Differences E1, E4, E5, E6, E7, and E8 indicate the difference when the amount of stored power exceeds the upper limit, i.e., the difference when the battery is overcharged, and differences E2, E3, and E9 indicate the difference when the amount of stored power falls below the lower limit, i.e., the difference when the battery is overdischarged.

[0035] Chart 42 shows the charge / discharge amount En of the high-response battery 15 to compensate for the difference En shown in Chart 41. For example, as discharge amounts to compensate for the differences E1, E4, E5, E6, E7, and E8 in the case of overcharging in Chart 41, in addition to the charge / discharge amounts E-2 and E-1 from the previous period, charge / discharge amounts E1, E4, E5, E6, E7, and E8 are shown. Also, charge amounts E2, E3, and E9 to compensate for the differences E2, E3, and E9 in the case of overdischarge in Chart 41 are shown. Here, if periods in which the discharge amounts E5, E6, and E7 continue, such as during the long response period LP1, occur frequently, a load due to discharging may accumulate in the high-response battery 15, accelerating degradation. Similarly, if periods in which charging continues frequently occur, a load due to charging may accumulate in the high-response battery 15, accelerating degradation.

[0036] In contrast to the timing chart 40A described above, the timing chart 40B includes, in addition to charts 40 and 41, a chart 43 showing the charge and discharge amounts of the low-response battery 16. As shown in chart 43, during the long response period LP1, the low-response battery 16 is charged in response to instructions from the CEMS server 10 and the BM server 13 to compensate for the charge and discharge amounts E-2, E-1, and E1 of the high-response battery 15 during the long response period LP0 in chart 42. Here, the charge and discharge amount is calculated by summing E-2, E-1, and E1, and charging or discharging is determined according to the sign of the sum. Meanwhile, as shown in chart 42, the high-response battery 15 is charged at charge amounts E5' and E6', which are less than the charge amounts E5 and E6, respectively, during the long response period LP1, and is controlled to omit charging at charge amount E7.

[0037] In this way, in this embodiment, by having the low-response battery 16 share part of the compensation for charging and discharging by the high-response battery 15, the charging and discharging load on the high-response battery 15 can be reduced, and deterioration of the high-response battery 15 can be suppressed.

[0038] In this way, according to this embodiment, it is possible to reduce the load on the storage batteries that supply power to the community.

[0039] In the above example, the low-response battery 16 has a slower response speed to the CEMS server 10 than the high-response battery 15 due to the control by the BM server 13. Not limited to this configuration, when there is a difference in the response speed of multiple storage batteries depending on the configuration of the storage battery control device, the processing performance of the intervening server, the number of batteries, etc., a storage battery with a fast response speed corresponds to a high-response battery, and a storage battery with a slow response speed corresponds to a low-response battery.

[0040] In the above-described embodiment, the processing / control program that defines the operation of the control unit 103 of the CEMS server 10 is stored in the memory unit 102 of the CEMS server 10 or in the memory unit of another server device, and may be downloaded to each device via the network 11, or may be stored in a non-transitory recording / storage medium that can be read by each device, and read from the medium by each device.

[0041] Although the embodiments have been described above based on the drawings and examples, it should be noted that those skilled in the art can easily make various modifications and alterations based on the present disclosure. Therefore, it should be noted that these modifications and alterations are included in the scope of the present disclosure. For example, the functions included in each means, step, etc. can be rearranged so as not to be logically inconsistent, and multiple means, steps, etc. can be combined or divided into one. [Explanation of symbols]

[0042] 1. Community 10 CEMS Server 11, 17 Network 12 strains 13 BM Server 14 Power load 15 Storage battery (high-response battery) 16 Storage battery (low response battery) 18 Power generation facilities 101 Communications Department 102 Storage section 103 Control Unit

Claims

1. The Communications Department and a plurality of storage batteries that discharge power consumed in a jurisdiction and charge surplus power, and a control unit that communicates with the communication unit; the control unit derives a difference between a storage amount of a first storage battery in a first period and a reference, and sends an instruction to a second storage battery having a slower response speed than the first storage battery to charge or discharge the difference in a second period longer than the first period; Server device.

2. In claim 1, the control unit transmits an instruction to charge or discharge the difference to the first storage battery during a first period after the first period in which the difference is derived; Server device.

3. A power control system having a plurality of storage batteries that discharge power consumed in a jurisdiction and charge surplus power, and a server device that communicates with the plurality of storage batteries, the server device derives a difference between an amount of power stored in a first storage battery during a first period and a reference, and sends an instruction to a second storage battery having a slower response speed than the first storage battery to charge or discharge the difference during a second period longer than the first period; Power control system.

4. An operation method of a power control system having a plurality of storage batteries that discharge power consumed in a jurisdiction and charge surplus power, and a server device that communicates with the plurality of storage batteries, comprising: the server device deriving a difference between a storage amount of a first storage battery in a first period and a reference, and sending an instruction to a second storage battery having a slower response speed than the first storage battery to charge or discharge the difference in a second period longer than the first period, How it works.

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