Electric power control system

Abstract

This electric power control system 100 comprises: a controller 8 which is provided to a storage battery 3 and which has a battery storage unit 8a that temporarily stores charge / discharge data in which a charge / discharge state is associated with a time and a processing unit 8b that controls the charge / discharge state of the storage battery 3 in accordance with a set charge / discharge schedule; and a server device 9 which is communicably connected to the controller 8. The server device 9 is configured to analyze the charge / discharge data within a prescribed first period so as to output an analysis result for each prescribed second period, adjust the charge / discharge schedule for each second period on the basis of the analysis result, and transmit the adjusted charge / discharge schedule to the controller 8.

Description

Power Control System

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

[0002] Patent Document 1 discloses a charging control method for a storage battery installed in a residence. In this residence, grid interconnection between a commercial power source and a photovoltaic power generation system is implemented. The storage battery is charged from the commercial power source or the photovoltaic power generation system. The stored electric power is consumed by the electrical loads of the residence as needed.

[0003] In implementing this method, a controller sets one of a plurality of operation modes to control charging and discharging of the storage battery. For example, when there is a sign that a power outage will occur in the commercial power grid due to occurrence of a disaster or the like, the controller sets the operation mode of the storage battery to a typhoon mode, and charging is started to secure a sufficient remaining capacity in the storage battery.

[0004] Japanese Patent Application Laid-Open No. 2021-132506

[0005] How users use a storage battery is considered to vary from user to user. However, the aforementioned controller only controls charging and discharging in accordance with pre-programmed operation modes.

[0006] An object of the present disclosure is to optimize charging and discharging control of a storage battery according to individual usage patterns of users.

[0007] One aspect of the present disclosure provides a power control system comprising: a rechargeable battery; a switching unit for switching between a charging state in which the battery is charged from a power source and a discharging state in which the battery is discharged to an electrical load of a consumer; a battery storage unit provided in the battery for temporarily storing charge / discharge data, which is information that links the charge / discharge state to time; and a controller having a processing unit that controls the charge / discharge state of the battery according to a set charge / discharge schedule through control of the operation of the switching unit; and a server device connected to the controller in a communicative manner, wherein the server device acquires the charge / discharge data from the controller, analyzes the charge / discharge data within a predetermined first period, outputs analysis results for each predetermined second period that is included in the first period but shorter than the first period, adjusts the charge / discharge schedule for each second period based on the analysis results, and transmits the adjusted charge / discharge schedule to the controller.

[0008] According to this disclosure, the charging and discharging control of the battery can be optimized according to the individual user's usage.

[0009] Block diagram of the power control system according to the embodiment. A graph showing an example of monthly charge amounts. A graph showing an example of a comparison of monthly charge amounts between the previous year and the current year. A graph showing an example of a comparison of discharge amounts for each day of the week between the week before last and last week. A graph showing an example of adjusting the charge / discharge schedule based on the discharge amount results for each day of the week. A graph showing another example of adjusting the charge / discharge schedule based on the discharge amount results for each day of the week.

[0010] 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.

[0011] The power control system according to this embodiment comprises a rechargeable battery, a switching unit that switches between a charging state in which the battery is charged from a power source and a discharging state in which the battery is discharged to the customer's electrical load, a battery storage unit provided in the battery that temporarily stores charge / discharge data, which is information that links the charge / discharge state to time, and a controller having a processing unit that controls the charge / discharge state of the battery according to a set charge / discharge schedule through control of the operation of the switching unit, and a server device that is communicably connected to the controller, wherein the server device acquires the charge / discharge data from the controller, analyzes the charge / discharge data within a predetermined first period, outputs the analysis results for each predetermined second period that is included in the first period but is shorter than the first period, adjusts the charge / discharge schedule for each second period based on the analysis results, and transmits the adjusted charge / discharge schedule to the controller.

[0012] According to the above configuration, the server device acquires charge and discharge data from the controller installed in each user's battery and outputs analysis results for each of the multiple second periods belonging to the first period. The charge and discharge schedule is adjusted for each second period based on these analysis results. The controller controls the charge and discharge state according to the adjusted charge and discharge schedule. This makes it possible to optimize charge and discharge control to suit how each user's battery is used.

[0013] In other embodiments, the first period may be one year and the second period may be one month.

[0014] In another embodiment, the server device may analyze the charge / discharge data for one year and output the charge level for each month.

[0015] In other embodiments, the first period may be one week or one month, and the second period may be one day.

[0016] In other embodiments, the server device may analyze the charge / discharge data for a week or a month and output the discharge level for each day of the week.

[0017] In another embodiment, if the most recent first period is referred to as the most recent first period, and the first period immediately preceding the most recent first period is referred to as the previous first period, the server device may compare the analysis results for the second period within the most recent first period with the analysis results for the same second period within the previous first period, and adjust the charge / discharge schedule for the second period based on the comparison of the analysis results.

[0018] In other embodiments, the charge / discharge schedule may include at least one of the following: SOC upper limit, whether or not charging is required due to purchased electricity, charging start time, and charging speed.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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).

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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 backflowed into the power grid 2. In addition, the battery 3 can supply power to the electrical load 92 as needed.

[0027] 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.

[0028] 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.

[0029] The controller 8 includes a battery storage unit 8a, a 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.

[0030] 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.

[0031] The processing unit 8b of the controller 8 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.

[0032] 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.

[0033] 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."

[0034] Examples of data indicating the "charge / discharge state" include the State of Charge (SOC) value and / or Depth of Discharge (DoD) value. The SOC value and DoD value may be measured by a battery management unit (BMU) built into the battery, or by the controller 8.

[0035] The charge and discharge data stored in the controller 8 is uploaded to the server device 9 at a predetermined interval (for example, every day). In the above example, at least one of the current value time series data, daily charge amount data, daily discharge amount data, SOC time series data, and DoD time series data is uploaded to the server device 9.

[0036] 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 for each customer over several years. The server processing unit 9b analyzes the charge and discharge data stored in the server storage unit 9a and performs processing to adjust the charge and discharge schedule for each customer. The "charge and discharge schedule" is not limited to a temporal meaning but includes the overall plan for charge and discharge control. The "charge and discharge schedule" may include the charging start time when the charge and discharge state of the battery 3 is switched to the self-charging state, and the charging completion time when the charge and discharge state of the battery 3 is switched from the self-charging state to the discharge state. In addition, the "charge and discharge schedule" may include the charging speed (also called the charging rate) of the battery 3 while the self-charging state is set, the upper limit of the SOC value of the battery 3 at the charging completion time, whether or not charging of the battery 3 is required in the external charging state, and the external charging start time and external charging end time if external charging is required.

[0037] In order to extend the lifespan of the battery 3 by implementing charge and discharge control tailored to the individual lifestyles of each customer, the charge and discharge schedule is not uniform.

[0038] For example, the charge-discharge schedule is adjusted for each day of the week. Here, the amount of electricity consumed by the electrical load tends to increase when the consumer is inside the house 91, but which days of the week the consumer spends the most time inside the house 91 varies depending on the individual consumer's lifestyle (for example, which days of the week are business days and holidays, whether or not they can work from home, whether or not they spend their holidays outside, etc.). If the charge-discharge schedule is set for each day of the week, compared to when the charge-discharge schedule is set uniformly regardless of the day of the week, the charge-discharge control can be optimized to suit the individual circumstances of the consumer (how the battery is used).

[0039] For example, the charge-discharge schedule is adjusted monthly (or seasonally (i.e., every few months)). Here, the amount of power generated by the distributed power source 1 and the amount of charge in the battery 3 in the self-charging state depend on the amount of solar radiation received by the solar cell module. Solar radiation fluctuates in a one-year cycle, strongly dependent on changes in the sun's diurnal motion (sunrise time, daylight hours, and sunset time). If the charge-discharge schedule is set monthly (or seasonally), the charge-discharge control can be optimized to take into account the fluctuations in solar radiation, compared to when the charge-discharge schedule is set uniformly throughout the year.

[0040] The server device 9 analyzes the charge and discharge data within a predetermined first period and outputs the analysis results for each predetermined second period that is included in the first period but is shorter than the first period. The server device 9 adjusts the charge and discharge schedule for each second period.

[0041] When adjusting the charge / discharge schedule on a monthly basis, the second period is one month. The first period is one year, encompassing all months. However, when adjusting the charge / discharge schedule seasonally, the second period can be multiple months. For example, in a region with four seasons in a year, the second period may be three months. In this case as well, the first period is one year, encompassing all seasons.

[0042] For example, as shown in Figure 2, the server device 9 analyzes charge and discharge data for one year and outputs the charge level for each month. The charge level is an index that represents the amount of charge in stages. The charge level for each month is determined by simply averaging the daily charge amount for all days of that month and comparing that average value with the charge threshold.

[0043] Level A is the category where the charge level is above the first charge level threshold, and there is a high probability that the SOC value can be charged to 100% using only self-charging. Level C is the category where the charge level is below the second charge level threshold, and charging using external charging is required. The intermediate level B is the category where the charge level is below the first charge level threshold but above the second charge level, and self-charging is prioritized while purchased power is used as needed.

[0044] Through this analysis result, whether to purchase power can be adjusted on a monthly basis as part of the charge-discharge schedule. Further, the data to be analyzed is the charged amount, that is, the actual operation record of the storage battery 3 of each individual consumer. The charged amount data includes not only the influence of diurnal motion astronomically determined by the calendar and latitude, but also the influence of climatic zones (for example, whether it is prone to fine weather (or conversely, cloudy weather) in a specific season compared with another region at the same latitude), the influence of the installation environment of the distributed power source 1 (for example, which direction the roof faces), the influence of the surrounding environment of the distributed power source 1 (for example, whether there are buildings or trees around the house that shade the distributed power source in a specific time period), and the influence of aging degradation of the distributed power source 1 (for example, the degree of dirt that leads to a decrease in power generation efficiency). Therefore, the charge-discharge schedule can be set on a monthly basis in accordance with the individual circumstances of each consumer.

[0045] Further, as shown in FIG. 3, the analysis result of each month in the most recent year (the daily charged amount in this example) may be compared with the analysis result of the same month in the previous year. As a result of the comparison, when the charged amount is decreased compared with the previous year, the decreased amount (absolute value) may be compared with a predetermined allowable value. When there is a month in which the decreased amount exceeds the allowable value, or when the number of months in which the decreased amount exceeds the allowable value exceeds a predetermined value, the consumer or the service provider may be notified of this fact and encouraged to perform maintenance.

[0046] When adjusting the charge-discharge schedule for each day of the week, the second period is one day. The first period is at least one week so as to include all days of the week. The second period may be a plurality of weeks (for example, 4 weeks, that is, approximately one month). When the second period is set to a plurality of weeks, a plurality of analysis results belonging to the same day of the week may be output as a single representative value using a statistical method such as averaging.

[0047] For example, as shown in FIG. 4, the server device 9 analyzes charge / discharge data for the most recent week (e.g., the past one week) and outputs the discharge amount for each day of the week. Next, the analysis result (discharge amount in this example) for each day of the week in the most recent week is compared with the analysis result for the same day of the week in the previous week (e.g., the week before the past week). For example, the server device 9 determines whether an amount of change (absolute value) in the discharge amount relative to the previous week exceeds an allowable value (e.g., 10% of the discharge amount in the previous week), and if the amount of change exceeds the allowable value, changes the upper limit of the SOC value for that day of the week. If the discharge amount has increased beyond the allowable range from the previous week, the upper limit of the SOC value is raised. If the discharge amount has decreased beyond the allowable range from the previous week, the upper limit of the SOC value is lowered. Through this analysis result, the target SOC value can be adjusted for each day of the week of the next week as part of the charge / discharge schedule.

[0048] After the upper limit of the SOC value for each day of the week of the next week is determined as described above, the server device 9 determines whether the upper limit of the SOC value can be achieved only with the self-charging state based on the current charge amount.

[0049] As shown in FIG. 5, if the upper limit of the SOC value cannot be achieved, it is determined that power purchase is required for charging, and a power purchase start time and a power purchase end time are determined. The power purchase time is set at night when photovoltaic power generation is impossible and the power purchase price is low. In this way, for each day of the week of the next week, as part of the charge / discharge schedule, whether power purchase is necessary, and if power purchase is required, the power purchase time period can be adjusted.

[0050] As shown in FIG. 6, if the upper limit of the SOC value can be achieved, the charging start time, charging end time, and charging rate are adjusted so as to secure a necessary and sufficient charge amount. For example, if the upper limit of the SOC value can be achieved even with a short charging time, the charging start time may be set later. Alternatively, the charging start time may be set around sunrise to lengthen the charging time and lower the charging rate. In this way, for each day of the week of the next week, as part of the charge / discharge schedule, the charging start time and charging rate can be adjusted. In addition to adjusting the charging start time and charging rate, adjustment may be performed by advancing the charging completion time or the like.

[0051] The above embodiment is merely an example, and the above configuration can be appropriately modified within the scope of the present disclosure.

[0052] This disclosure may include the following embodiments: (Embodiment 1) A power control system comprising: a rechargeable battery; a switching unit for switching between a charging state in which the battery is charged from a power source and a discharging state in which the battery is discharged to a customer's electrical load; a battery storage unit provided in the battery for temporarily storing charge / discharge data, which is information that links the charge / discharge state to time; and a controller having a processing unit that controls the charge / discharge state of the battery according to a set charge / discharge schedule through control of the operation of the switching unit; and a server device connected to the controller in a communicative manner, wherein the server device is configured to: acquire the charge / discharge data from the controller; analyze the charge / discharge data within a predetermined first period; output analysis results for each predetermined second period that is included in the first period and shorter than the first period; adjust the charge / discharge schedule for each second period based on the analysis results; and transmit the adjusted charge / discharge schedule to the controller. (Embodiment 2) The power control system according to Embodiment 1, wherein the first period is one year and the second period is one month. (Aspect 3) The power control system according to aspect 2, wherein the server device analyzes the charge and discharge data for one year and outputs the charge level for each month. (Aspect 4) The power control system according to claim 1, wherein the first period is one week or one month and the second period is one day. (Aspect 5) The power control system according to claim 4, wherein the server device analyzes the charge and discharge data for one week or one month and outputs the discharge level for each day of the week. (Aspect 6) The power control system according to any one of aspects 1 to 5, wherein, when the most recent first period is referred to as the most recent first period and the first period immediately preceding the most recent first period is referred to as the previous first period, the server device compares the analysis results for the second period within the most recent first period with the analysis results for the same second period within the previous first period, and adjusts the charge and discharge schedule for the second period based on the comparison of the analysis results.(Aspect 7) The power control system according to any one of aspects 1 to 6, wherein the charge / discharge schedule includes at least one of the following: upper limit of SOC value, whether or not charging is required by purchased electricity, charging start time, and charging speed.

[0053] 1. Distributed power source 2. Power grid 3. Storage battery 4. Power conditioner 5. Distribution board 6. Electric meter 7. Control unit 8. Controller 8a. Battery memory unit 8b. Processing unit 8c. Input / output interface 9. Server device 9a. Server memory unit 9b. Server processing unit 91. House 92. Electrical load 93. Telecommunication line 100. Power control system

Claims

A rechargeable battery that can be repeatedly charged and discharged, A switching unit that switches between a charging state in which the storage battery is charged from a power source and a discharging state in which the storage battery is discharged to the customer's electrical load, A battery storage unit is provided in the battery and temporarily stores charge / discharge data, which is information that links the charge / discharge state to time. The controller has a processing unit that controls the charge / discharge state of the battery according to a set charge / discharge schedule by controlling the operation of the switching unit. A server device that is connected to the controller in a manner that allows communication, Equipped with, The aforementioned server device The charge / discharge data is acquired from the controller, The charge and discharge data within a predetermined first period is analyzed, and the analysis results are output for each predetermined second period that is included in the first period and is shorter than the first period. Based on the analysis results, the charge / discharge schedule is adjusted for each of the second periods. The adjusted charge / discharge schedule is transmitted to the controller. It is structured in such a way. Power control system. 　 The first period is one year, and the second period is one month. The power control system according to claim 1. 　 The server device analyzes the charge / discharge data for one year and outputs the charge level for each month. The power control system according to claim 2. 　 The first period is one week or one month, and the second period is one day. The power control system according to claim 1. 　 The server device analyzes the charge / discharge data for one week or one month and outputs the discharge level for each day of the week. The power control system according to claim 4. 　 If the most recent first period is referred to as the most recent first period, and the first period immediately preceding the most recent first period is referred to as the previous first period, The aforementioned server device The analysis results covering the second period within the most recent first period are compared with the analysis results covering the same second period within the previous first period. Based on the comparison of the aforementioned analysis results, the charge-discharge schedule for the second period is adjusted. A power control system according to any one of claims 1 to 5. 　 The charge / discharge schedule includes at least one of the following: SOC value upper limit, whether charging is required due to purchased electricity, charging start time, and charging speed. A power control system according to any one of claims 1 to 5.

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