Power control system

Abstract

A power control system 100 comprises: a controller 8 provided in a storage battery 3; a target period selection unit 11 that selects and inputs at least one from among a plurality of target periods having mutually different lengths; and a server device 9 communicably connected to the controller 8. The server device 9 has: a server storage unit 9a that stores charge / discharge data transmitted from the controller 8; and a server processing unit 9b that analyzes how the storage battery 3 is used for the target period selected by the target period selection unit 11 on the basis of the charge / discharge data stored in the server storage unit 9a. A battery storage unit 11 has a plurality of storage regions 15a to 15c that store charge / discharge data for each of the plurality of target periods. Each of the plurality of storage regions 15a to 15c stores a group of charge / discharge data for each aggregation period, set to be shorter than a corresponding target period in accordance with the corresponding target period.

Description

Power Control System

[0001] The present disclosure relates to a power control system.

[0002] Patent Document 1 discloses a deterioration suppression system for a storage battery installed in a residence. This system includes, as a part of the equipment mounted on the battery, a storage unit that stores a program for suppressing deterioration and information necessary for executing the program.

[0003] International Publication No. 2024 / 176830

[0004] To execute the program for suppressing deterioration, the storage unit needs to store time-series data of a plurality of indicators such as current and temperature that are sequentially output at a sampling cycle of a second unit over a long period of time.

[0005] An object of the present disclosure is to reduce the capacity of the storage unit and reduce the amount of communication.

[0006] One aspect of the present disclosure is a power control system including: a rechargeable and dischargeable storage battery; a controller provided in the storage battery, the controller having a battery storage unit that stores charge / discharge data indicating a charge / discharge state of the storage battery, and a battery processing unit that can read and write information stored in the battery storage unit; a target period selection unit that selectively inputs at least any one from a plurality of target periods having different lengths from each other; and a server device communicably connected to the controller, the server device having a server storage unit that stores charge / discharge data transmitted from the controller, and a server processing unit that analyzes how the storage battery is used for the target period selected by the target period selection unit based on the charge / discharge data stored in the server storage unit, wherein the battery storage unit has a plurality of storage areas that store the charge / discharge data for each of the plurality of target periods, and each of the plurality of storage areas stores a group of charge / discharge data for each aggregation period set shorter than the corresponding target period in accordance with the target period.

[0007] According to the present disclosure, the capacity of the storage unit can be reduced, and the amount of communication can be reduced.

[0008] Block diagram of the power control system according to the embodiment. Block diagram of the control unit in Figure 1. Conceptual diagram of the battery storage unit in Figure 2.

[0009] Embodiments will be described below with reference to the drawings. The same or corresponding elements are denoted by the same reference numerals throughout the drawings, and redundant detailed descriptions will be omitted.

[0010] A power control system according to one form of this implementation comprises a rechargeable battery, a controller provided with the battery having a battery storage unit that stores charge / discharge data indicating the charge / discharge state of the battery, and a battery processing unit that can read and write information stored in the battery storage unit, a target period selection unit that selects and inputs at least one of a plurality of target periods of different lengths, and a server device that is communicably connected to the controller having a server storage unit that stores charge / discharge data transmitted from the controller, and a server processing unit that analyzes how the battery is used for the target period selected by the target period selection unit based on the charge / discharge data stored in the server storage unit, wherein the battery storage unit has a plurality of storage areas that store the charge / discharge data for each of the plurality of target periods, and each of the plurality of storage areas stores a group of charge / discharge data for each aggregation period set to be shorter than the target period according to the corresponding target period.

[0011] According to the above configuration, the analysis processing related to the storage battery is performed by a server device rather than a controller installed in the storage battery, and the storage unit of the power control system is divided into a battery storage unit installed in the storage battery that stores charge and discharge data, and a server storage unit in the server device. This distribution reduces the amount of information that the battery storage unit is responsible for storing, and thus reduces the capacity of the battery storage unit. The battery storage unit has multiple storage areas for each analysis period, and in each storage area, a group of charge and discharge data is stored for each aggregation period. Compared to the case where all charge and discharge data output sequentially with a sampling period of seconds is stored, the amount of data that needs to be stored in the battery storage unit can be compressed by a value obtained by dividing the sampling period by the aggregation period (for example, if the sampling period is 1 second and the aggregation period is 1 day (86,400 seconds), the capacity can be compressed to 1 / 86,400). As a result, the amount of data sent from the controller to the server device for analysis is reduced, and the amount of data that needs to be stored in the server storage unit for analysis is also reduced.

[0012] Other forms of this implementation of a power control system may further include a display unit for displaying the analysis results obtained by the server device.

[0013] In a power control system relating to another form of this implementation, if a display request is input to the display unit when the data necessary for the analysis of the target period is not yet available, the server device may output information indicating the interim results of the analysis.

[0014] The following describes specific examples of this disclosure in detail based on the drawings. Note that parts with the same reference numerals appearing in multiple drawings indicate the same or equivalent parts or components. Furthermore, the embodiments shown below are examples of the technical concept of this disclosure and do not limit this disclosure to the following. Also, the dimensions, materials, shapes, relative arrangements, etc., of the components described below are intended as examples only, and are not intended to limit the scope of this disclosure unless specifically stated. Furthermore, the content described in one embodiment or example is applicable to other embodiments and examples. Also, the size and positional relationships of components shown in the drawings may be exaggerated for clarity of explanation.

[0015] Referring to Figure 1, the power control system 100 connects the distributed power source 1, which is installed in the customer's house 91 or on its premises, to the commercial power grid 2. The customer's house 91 is equipped with electrical appliances such as household appliances as electrical loads 92 that consume electricity.

[0016] Distributed power source 1 is, as an example, a photovoltaic power generation device having a solar cell consisting of a large number of solar cells. The solar cell is installed, for example, on the roof of a house 91 and generates electricity by receiving sunlight. Due to this property, the solar cell can generate electricity during the time of day when sunlight is shining on it. Distributed power source 1 may also be a power generation device that utilizes renewable energy such as a wind power generation device or a small hydroelectric power generation device, or it may be a fuel cell or a cogeneration device.

[0017] The power control system 100 comprises a battery 3, a power conditioner 4, a distribution board 5, and an electric meter 6. The battery 3 is a rechargeable secondary battery, such as a lithium-ion battery, nickel-metal hydride battery, or lead-acid battery. The secondary battery is composed of multiple battery cells. The battery 3 is installed in the customer's house 91 or on its premises. The power conditioner 4 is connected to the power generation elements of the distributed power source 1 (solar cell modules in the above example), the battery 3, and the distribution board 5. The distribution board 5 is connected to the commercial power grid via the electric meter 6 and is also connected to the electrical load 92. The electric meter 6 is located on the power grid 2 and measures the power received from the commercial power source (i.e., power purchased from the power supplier) and the power that flows back into the commercial power grid 2 (i.e., power sold to the power supplier).

[0018] The power conditioner 4 has the functions of converting DC to AC, switching the power supply state of the distributed power source 1 (in other words, the destination of the power generated by the distributed power source 1), and switching the charge and discharge state of the storage battery 3. In order to act as a switching unit for switching the charge and discharge state, the power conditioner 4 has multiple switches (not shown) interposed on the wiring for interconnecting the power generation elements of the distributed power source 1, the storage battery 3, and the distribution board 5.

[0019] The power supply states of the distributed power source 1 include a self-charging state in which the power generated by the distributed power source 1 is supplied to the storage battery 3, a self-consumption state in which the DC power generated by the distributed power source 1 is converted to AC and supplied to the electrical load 92, and a reverse power flow state in which the DC power generated by the distributed power source 1 is converted to AC and flowed back into the power grid 2. These states can occur simultaneously. For example, around noon on a sunny summer day, the amount of power generated per unit time by the distributed power source 1 is high. In such a case, the power generated by the distributed power source 1 may be supplied to the electrical load from the power conditioner 4 via the distribution board 5, or reverse power flowed back via the distribution board 5, and then supplied to the storage battery 3 from the power conditioner 4.

[0020] The charging and discharging states of the battery 3 include a charging state in which the battery 3 is charged, and a discharging state in which the DC power stored in the battery 3 is converted to AC power and then discharged to the distribution board 5 and subsequently to the electrical load 92. The charging state includes the above-mentioned self-charging state and an external charging state in which the battery 3 is charged with power supplied from the commercial power source. The self-charging state and the external charging state can occur simultaneously. In the external charging state, the AC power from the commercial power source is converted to DC power by the power conditioner 4 or a separately provided converter, and then supplied to the battery 3.

[0021] In this way, the battery 3 can store surplus power, which is obtained by subtracting the power consumed by the electrical load 92 from the power generated by the distributed power source 1, and which is not back-flowed into the power grid 2. In addition, the battery 3 can supply power to the electrical load 92 as needed.

[0022] The power control system 100 further comprises a control unit 7, which comprises a controller 8 and a server device 9. Both the controller 8 and the server device 9 are computers, which are the main components of the apparatus, system, or method according to this embodiment. The functions of the main components of the apparatus, system, or method in this disclosure are realized by the computer executing a program. The computer comprises a processor, which operates according to a program, as its main hardware configuration. The processor can be of any type as long as it can realize its functions by executing a program. The processor consists of one or more electronic circuits, including a semiconductor integrated circuit (IC) or a large-scale integration (LSI). Here, we refer to them as ICs and LSIs, but the name changes depending on the degree of integration, and they may also be called system LSIs, VLSIs (very large-scale integrations), or ULSIs (ultra-large-scale integrations). Field programmable gate arrays (FPGAs), which are programmed after the manufacture of the LSI, or reconfigurable logic devices that can reconfigure the junction relationships inside the LSI or set up the circuit compartments inside the LSI, can also be used for the same purpose. Multiple electronic circuits may be integrated onto a single chip or provided on multiple chips. Multiple chips may be integrated into a single device or provided on multiple devices. The program is recorded on a non-temporary recording medium such as a computer-readable ROM, optical disc, or hard disk drive. The program may be pre-stored on the recording medium or supplied to the recording medium via a wide-area communication network, including the Internet.

[0023] The controller 8 is individually assigned to each customer and is installed in the customer's house 91. The controller 8 is communicatively connected to the server device 9 via a telecommunications line 93. The server device 9 is located outside the house 91. The server device 9 centrally controls the charging and discharging of the storage batteries 3 installed in each of the multiple customers. The server device 9 may be implemented in a virtual environment on the cloud. The server device 9 also analyzes how the storage batteries 3 are used for each customer.

[0024] The controller 8 includes a battery storage unit 8a, a battery processing unit 8b, and an input / output interface 8c. The input / output interface 8c is connected to the storage battery 3 and the electric meter 6, and acquires data or information necessary for control from the storage battery 3 and the electric meter 6. The power control system 100 may be equipped with sensors on the wiring connecting its components that detect electrical characteristics such as current and voltage. Examples of such sensors include a voltage sensor provided on the secondary side of the electric meter 6 and a current sensor provided between the storage battery 3 and the power conditioner 4. In such cases, the controller 8 is also connected to the sensors and acquires information output from the sensors.

[0025] The input / output interface 8c of the controller 8 outputs operation command signals to the power conditioner 4. For example, the controller 8 controls the operation of switches on the power conditioner 4. Through this control, the charging and discharging state of the battery 3 is controlled.

[0026] The battery processing unit 8b of the controller 8 can read and write information stored in the battery storage unit 8a. The battery processing unit 8b also controls the charging and discharging state of the battery 3 according to the set charging and discharging schedule. The charging and discharging schedule is stored in the battery storage unit 8a. The charging and discharging schedule is adjusted by the server device 9 as described later and is updated as time elapses since the start of operation of the battery 3 at each customer.

[0027] The controller 8 collects charge / discharge data linked to the charge / discharge state of the storage battery 3 over time, and the collected charge / discharge data is temporarily stored in the battery storage unit 8a. The "time" to be linked includes not only time data representing hours, minutes, and seconds, but also calendar data representing year, month, and day.

[0028] As data indicating the "charge / discharge state," the current value flowing into or from the battery 3 can be exemplified. When the current value is positive, the battery 3 is in a discharge state, and when the current value is negative, the battery 3 is in a charging state. The method for generating charge / discharge data related to the current value is not particularly limited. For example, the controller 8 may sequentially acquire the current value, as an example of a physical quantity representing the charge / discharge state, from a current sensor at a predetermined sampling period (e.g., several milliseconds), and associate the acquired current value with the acquisition time. Alternatively, the daily charge and discharge amounts may be calculated by individually integrating positive and negative current values ​​with an integration interval of one day. In this case, the daily charge and discharge amounts can also be exemplified as data indicating the "charge / discharge state."

[0029] Furthermore, examples of data indicating the "charge / discharge state" include the voltage value of the battery 3, the temperature of the battery 3, the SOC (State of Charge) value, and / or the DoD (Depth of Discharge) value. The SOC value and DoD value may be measured by a BMU (battery management unit) built into the battery, or by a controller 8.

[0030] The server device 9 has a server storage unit 9a and a server processing unit 9b. The server storage unit 9a stores charge and discharge data transmitted from the controller 8. Based on the charge and discharge data stored in the server storage unit 9a, the server processing unit 9b analyzes how the battery 3 is used for the target period selected by the target period selection unit (see Figure 2). Specifically, "how it is used" refers to the user's power usage trends, such as when charging and discharging occur during the day and at night, and to what extent nighttime power is covered by power charged with surplus PV power during the day. Such power usage trends can be determined based on information such as the charging completion timing and discharging start timing of the battery 3, i.e., charge and discharge data.

[0031] The "target period" refers to the period over which the usage of the storage battery 3 is analyzed. Examples of target periods include 2 years, 1 year, 1 season (3 months in regions where four seasons are recognized in a year), 1 month, 2 weeks, 1 week (7 days), and 1 day. In this embodiment, as merely one example, there are three candidate target periods: 2 years, 2 weeks, and 7 days.

[0032] Referring to Figure 2, the power control system 100 further includes a target period selection unit 11 for selecting and inputting at least one of a plurality of target periods of different lengths, and a display unit 12 for displaying analysis results output from the server device 9. The selection input operation in the target period selection unit 11 may be performed by a consumer or a service provider. The same applies to the recipient of the information displayed in the display unit 12. The target period selection unit 11 and the display unit 12 may be provided on an operation panel mounted on a housing that contains the battery cells of the storage battery 3. The target period selection unit 11 may also be an operation switch that is set on a dedicated application installed on an information terminal device (e.g., a personal computer, smartphone, tablet terminal, etc.) handled by a consumer or service provider and displayed on the display unit 12.

[0033] The customer or service provider selects at least one of several target periods (in this example, 2 years, 2 weeks, and 7 days) using the target period selection unit 11. Only one target period may be selected, or multiple periods may be selected.

[0034] Referring to Figure 3, the battery storage unit has multiple storage areas 15a to 15c for storing charge and discharge data for multiple target periods. Each of the multiple storage areas 15a to 15c stores a group of charge and discharge data for each aggregation period set to be shorter than the corresponding target period. In this example, there are three candidate target periods, and the multiple storage areas include three areas: a first storage area 15a corresponding to a 2-year target period, a second storage area 15b corresponding to a 2-week target period, and a third storage area 15c corresponding to a 7-day target period.

[0035] Charge / discharge data is a group of data for multiple indicators related to the charge / discharge state (e.g., current, voltage, temperature, charging time, discharging time, charge amount, discharge amount, SOC value, DoD value, etc.), and the data for each indicator is time-series data acquired sequentially at a predetermined sampling period. The controller 8 sequentially inputs data for multiple indicators related to the charge / discharge state at a predetermined sampling period. If the sampling period is, for example, 1 second, the number of data points for each indicator will be 3,600 per hour and 86,400 per day. In this embodiment, the battery storage unit 8a does not store all of this time-series data, but rather stores a group of data aggregated in predetermined aggregation period units as charge / discharge data within a range that enables analysis by the server device 9.

[0036] For example, in a 7-day target period, the aggregation period is set to 1 hour. In this case, only one group of data for multiple indicators is stored in the third memory area 15c for this 1-hour aggregation period. Since there are 168 aggregation periods in a 7-day target period, the third memory area 15c only needs to store 168 groups.

[0037] If the indicator is current, one data point representing the average value of multiple current data acquired during a one-hour aggregation period may be stored as part of a group of data. The same applies to voltage and temperature. In the case of charging time, discharging time, charge amount, and discharge amount, one data point representing the cumulative value of multiple data acquired during a one-hour aggregation period may be stored as part of a group of data. In the case of SOC value and DoD value, one data point representing the maximum value of multiple data acquired during a one-hour aggregation period may be stored as part of a group of data.

[0038] For example, in a two-week target period, the aggregation period is set to one day. In this case, only one group of data for multiple indicators is stored in the second memory area 15b for this one-day aggregation period. For aggregation, 24 hours of data stored in the third memory area 15c is read out, and statistical processing (averaging, summation, or maximum sampling) according to the data type is performed on the read data as described above. This yields one group of data corresponding to one day of aggregation. Since there are 14 aggregation periods in a two-week target period, the second memory area 15b only needs to store 14 groups.

[0039] For example, in a two-year target period, the aggregation period is set to one month. In this case, only one group of data for multiple indicators for this one-month aggregation period is stored in the first memory area 15a. When aggregation is performed, when two weeks' worth of data has accumulated in the second memory area 15b, statistical processing (averaging, cumulative, or maximum sampling) according to the data type can be performed on that data as described above. This yields one group of data corresponding to half of the one-month aggregation period. This provisional data is temporarily stored in the area of ​​the first memory area 15a that stores the latest month. Next, when two weeks' worth of data has accumulated in the second memory area 15b, the same processing can be performed using the temporarily stored data and the data in the second memory area 15b to obtain one group of data for four weeks. The remainder is obtained by adding the one day's worth of data accumulated in the second area according to the number of days in the month, thereby obtaining one group of data corresponding to the one-month aggregation period. Since there are 24 aggregation periods in a two-year target period, the first memory area 15a only needs to store 24 groups.

[0040] The battery processing unit 8b transmits only the data corresponding to the target period selected in the target period selection unit to the server device 9. The battery processing unit 8b may transmit the data aggregated within each target period, or it may transmit the data corresponding to each aggregation period, or it may transmit the data aggregated within multiple aggregation periods after several aggregation periods have elapsed.

[0041] The server device 9 analyzes how the battery 3 is used for the target period selected in the target period selection unit. The analysis covers usage for periods shorter than the target period but longer than or equal to the aggregation period. For a 2-year target period, data aggregated monthly is used to analyze usage by season or month. For a 2-week target period, data aggregated daily is used to analyze usage on a weekly basis. For a 7-day target period, data aggregated hourly is used to analyze usage on a daily basis.

[0042] The server storage unit 9a stores data transmitted from the controller and also stores analysis results. When a customer or service provider requests the output of analysis results, the server device 9 outputs the analysis results stored in the server storage unit 9a for display on the display unit.

[0043] Thus, according to this embodiment, the analysis processing related to the storage battery 3 is performed by the server device 9, rather than by the controller 8 provided in the storage battery 3. The storage unit of the power control system 100 is divided into a battery storage unit 8a provided in the storage battery 3 that stores charge and discharge data, and a server storage unit 9a in the server device 9. This distribution reduces the amount of information that the battery storage unit 8a is responsible for storing, and thus reduces the capacity of the battery storage unit 8a.

[0044] The battery storage unit 8a has a plurality of storage areas 15a to 15c for each analysis target period, and a group of charge and discharge data is stored for each aggregation period in each of the storage areas 15a to 15c. Compared with the case where all charge and discharge data sequentially output at a second-based sampling period are all stored, the amount of data to be stored in the battery storage unit 8a can be compressed by a value obtained by dividing the sampling period by the aggregation period. Accordingly, the amount of data transmitted from the controller 8 to the server device 9 for an analysis request can also be reduced, and the amount of data to be stored in the server storage unit 9a for analysis can also be reduced.

[0045] There are cases where an output request for an analysis result is input in a state where data necessary for analyzing the target period is not complete. For example, a case is assumed where an output request is input one month after a two-year target period is selected. In such a case, the server device may output information indicating the intermediate progress of the analysis result. This makes it possible to partially satisfy the requirements of consumers or service providers.

[0046] The above embodiment is merely an example, and the above configuration can be appropriately modified within the scope of the present disclosure.

[0047] The server device 9 may change the charge and discharge schedule of the storage battery 3 based on the analysis result. The charge and discharge schedule refers to the overall daily charge and discharge control plan, and may include the charge amount, discharge amount, charge start time, charge completion time, upper limit of SOC value, upper limit of DoD value, whether charging by power purchase is necessary, and the like. When the charge and discharge schedule is changed, the server device 9 transmits the changed charge and discharge schedule to the controller 8. The controller 8 controls the operation of the power conditioner 4 in accordance with the transmitted charge and discharge schedule, and controls the charge and discharge state of the storage battery 3 through the control.

[0048] The present disclosure may include the following aspects. (Aspect 1) A rechargeable storage battery that can be repeatedly charged and discharged; A controller provided in the storage battery, the controller including a battery storage unit that stores charge / discharge data indicating a charge / discharge state of the storage battery, and a battery processing unit capable of reading and writing information stored in the battery storage unit; A target period selection unit that selectively inputs at least any one from a plurality of target periods having different lengths; A server device communicably connected to the controller, the server device including a server storage unit that stores charge / discharge data transmitted from the controller, and a server processing unit that analyzes usage of the storage battery for the target period selected by the target period selection unit based on the charge / discharge data stored in the server storage unit; wherein The battery storage unit has a plurality of storage areas that store the charge / discharge data for each of the plurality of target periods, Each of the plurality of storage areas stores a group of charge / discharge data for each aggregation period set shorter than the corresponding target period according to the corresponding target period, A power control system. (Aspect 2) The power control system according to Aspect 1, further comprising a display unit that displays an analysis result obtained by the server device. (Aspect 3) The power control system according to Aspect 2, wherein when a display request to the display unit is input in a state where data necessary for analysis of the target period is not complete, the server device outputs information indicating an intermediate progress of the analysis result.

[0049] 1 Distributed power source 2 Power grid 3 Storage battery 4 Power conditioner 5 Distribution board 6 Electricity meter 7 Control unit 8 Controller 8a Battery storage unit 15a to 15c Storage areas 8b Battery processing unit 8c Input / output interface 9 Server device 9a Server storage unit 9b Server processing unit 11 Target period selection unit 12 Display unit 91 House 92 Electrical load 93 Telecommunication line 100 Power control system

Claims

1. A power control system comprising: a rechargeable battery; a controller provided with the battery, having a battery storage unit that stores charge / discharge data indicating the charge / discharge state of the battery, and a battery processing unit that can read and write information stored in the battery storage unit; a target period selection unit that selects and inputs at least one of a plurality of target periods of different lengths; and a server device that is communicably connected to the controller, having a server storage unit that stores charge / discharge data transmitted from the controller, and a server processing unit that analyzes how the battery is used for the target period selected by the target period selection unit based on the charge / discharge data stored in the server storage unit, wherein the battery storage unit has a plurality of storage areas that store the charge / discharge data for each of the plurality of target periods, and each of the plurality of storage areas stores a group of charge / discharge data for each aggregation period set to be shorter than the target period according to the corresponding target period.

2. The power control system according to claim 1, further comprising a display unit for displaying analysis results obtained by the server device.

3. The power control system according to claim 2, wherein when a display request is input to the display unit while the data necessary for the analysis of the target period is not yet available, the server device outputs information indicating the interim progress of the analysis results.

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