JP5895157B2 - Charge / discharge control device - Google Patents

Description

  The present invention relates to a charge / discharge control device.

  The development of power systems for factories and general homes with a battery unit that can be charged and discharged has been extensive. In this type of system, in general, the battery unit is charged with power purchased from an electric power company, and the charging power is discharged during a time period when the amount of power consumption is relatively large for the purpose of peak cutting of the power. . However, if the cost required for charging is lower than the power charge at the time of discharging, charging is performed at a higher charge than at the time of discharging, which is not economical. In order to realize more economical power supply, a conventional method has been proposed in which charge / discharge control is performed by comparing the average value of the power charge when the battery unit is charged with the current power charge of the commercial power supply (the following patents) Reference 1).

JP 2010-233362 A

  However, in the conventional method using this average value, the charged electric power may be discharged at a cost higher than the current power charge of the commercial power supply, so there is room for improvement in economical charge / discharge control.

  Then, an object of this invention is to provide the charging / discharging control apparatus which contributes to realization of economical charge or discharge control.

  A charging / discharging control device according to the present invention comprises: a charging / discharging circuit for charging and discharging a battery unit; and a charging / discharging control unit for controlling charging and discharging of the battery unit by controlling the charging / discharging circuit. The charge / discharge control unit is configured to charge power for the battery unit using the power rate information, and a power rate information acquisition unit for acquiring power rate information representing a power rate of power supplied from a commercial power source for a plurality of time zones. A plurality of charging charges required are set, and charging state information indicating the values of the plurality of charging capacities is stored in a state where the total charging capacity of the battery unit is divided into a plurality of charging capacities corresponding to the plurality of charging charges. A charge state management unit, and controls discharging of the battery unit based on the power rate information and the charge state information.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to provide the charging / discharging control apparatus which contributes to control implementation of economical charge or discharge.

1 is a schematic overall configuration diagram of a battery system according to an embodiment of the present invention. It is a figure which shows the electric power charge information which defined the electric power charge for every time slot | zone. It is a figure which shows the breakdown of a charge charge. It is a figure (a) which shows the charge charge of each time slot | zone at the time of commercial AC power utilization, and a figure (b) which shows the charge charge at the time of utilization of generated electric power. It is a figure which shows the structure of charge condition information. It is a figure which shows the charge condition information in specific time. 3 is an operation flowchart of the battery system according to the first embodiment of the present invention. It is a figure which shows the example of the charge status information updated with charge. It is a figure which shows the example of the charge condition information updated with discharge. It is a figure which shows the example of the charge condition information updated with discharge. It is a figure which shows a part of component of a charging / discharging control part. It is a figure which shows a part of component of a charging / discharging control part. 4 is an operation flowchart of a battery system according to a second embodiment of the present invention. 6 is an operation flowchart of a battery system according to a third embodiment of the present invention.

  Hereinafter, an example of an embodiment of the present invention will be specifically described with reference to the drawings. In each of the drawings to be referred to, the same part is denoted by the same reference numeral, and redundant description regarding the same part is omitted in principle. In this specification, for simplification of description, a symbol or reference that refers to information, signal, physical quantity, state quantity, member, or the like is written to indicate information, signal, physical quantity, state quantity or Names of members and the like may be omitted or abbreviated.

  FIG. 1 is a schematic overall configuration diagram of a battery system 1 that can also be referred to as a storage battery system or a power system according to an embodiment of the present invention. The battery system 1 includes a charge / discharge control unit 2, a power conversion unit 3, a power storage device 4, a display unit 11, and an operation unit 12, and may further include a power generation device 6. It may be considered that the battery system 1 further includes the power system 7 or the load 9. It can be considered that a charge / discharge control device is formed by the charge / discharge control unit 2 and the power conversion unit 3, and any component of the battery system 1 other than the charge / discharge control unit 2 and the power conversion unit 3 is further charged. It may be considered that it is included in the discharge control device. The power storage device 4 is provided with a battery unit 5 composed of one or more secondary batteries. The secondary battery forming the battery unit 5 is an arbitrary type of secondary battery, for example, a lithium ion battery or a nickel metal hydride battery. In the present embodiment, discharging and charging means discharging and charging of the battery unit 5 (more specifically, discharging and charging of each secondary battery in the battery unit 5) unless otherwise specified.

  The battery unit 5 is connected to the power conversion unit 3 and can output its own discharge power to the power conversion unit 3 and is charged when supplied with charging power from the power conversion unit 3. The power generation device 6 is, for example, a power generation device that generates power based on natural energy (solar, wind, hydropower, geothermal, etc.) and outputs generated power. Here, the power generation device 6 generates power based on sunlight. It is assumed that the solar power generation device outputs the generated power. The power generator 6 is connected to the power converter 3, and the generated power of the power generator 6 is output to the power converter 3. A power system 7 is also connected to the power conversion unit 3. The power system 7 is connected to a commercial power source 8 that generates and outputs commercial AC power. The load 9 is, for example, an industrial device or an electrical appliance in a factory, store, building, or general house where the battery system 1 is introduced, and is connected to the power conversion unit 3 and the power system 7.

  The power conversion unit 3 transfers power between the battery unit 5, the power generation device 6, the power system 7, and the load 9 under the control of the charge / discharge control unit 2, and performs necessary power conversion at the time of this transfer. Specifically, for example, the power conversion unit 3 has a plurality of power conversion circuits, converts the DC generated power from the power generation device 6 into other DC power, and uses the other DC power as charging power. A first function to be supplied to the unit 5; a second function for converting the DC discharge power from the battery unit 5 into AC power and outputting the AC power to the power system 7 or the load 9; A third function of converting commercial AC power supplied via the DC power into DC power and supplying the DC power to the battery unit 5 as charging power, and converting DC generated power from the power generator 6 into AC power A fourth function of outputting the AC power to the power system 7 or the load 9 is realized. When attention is paid to the first to third functions, the power conversion unit 3 functions as a charge / discharge circuit for charging and discharging the battery unit 5, so the power conversion unit 3 can also be called a charge / discharge circuit, or It can also be considered that a charge / discharge circuit is inherent in the power conversion unit 3.

  The load 9 is an AC power based on the discharged power of the battery unit 5 or the generated power of the power generation device 6 given through the power conversion unit 3, or the commercial AC power given from the commercial power source 8 through the power system 7. Alternatively, a combination of these electric powers is used as drive power to drive (ie, consume). However, the load 9 may be a DC load driven by DC power or may include the DC load. In this case, all or a part of the load 9 is discharged power of the battery unit 5. It is driven by the DC power based on the generated power of the power generator 6 or the commercial AC power from the commercial power supply 8, or the DC power based on a combination thereof.

The power conversion unit 3 or the battery system 1 includes a power terminal PT ₅ through which a discharge power or charging power current from the battery unit 5 passes, a power terminal PT ₆ through which a current generated by the power generator 6 passes, and a power system. 7 and a power terminal PT ₇ through which an AC power current input from the power converter 3 to the load 9 or an AC power current output from the power converter 3 to the power system 7 passes. A current sensor and a voltage sensor (not shown) for measuring current and voltage values at the terminals PT _{5 to} PT ₇ are provided. The current sensor and the voltage sensor output the measured current values and voltage values of the power terminals PT _{5 to} PT ₇ to the input / output power information acquisition unit 21 described later.

  The charge / discharge control unit 2 controls the operation of the power conversion unit 3 including the operation of the power conversion, and controls the charging and discharging of the battery unit 5 through the control of the operation of the power conversion unit 3. In addition, the charge / discharge control unit 2 can display a desired image on the display unit 11 by controlling the display unit 11 including a liquid crystal display. The operation unit 12 receives various instructions and information from the operator of the battery system 1 and transmits the instructions and information to the charge / discharge control unit 2. The operator is, for example, the owner, user, or maintenance manager (so-called service man) of the battery system 1. The operation unit 12 can include a touch panel on the display unit 11. The charge / discharge control unit 2 includes the respective parts referred to by reference numerals 21 to 25.

The input / output power information acquisition unit 21 receives the current value and the voltage value at each of the power terminals PT _{5 to} PT ₇ to acquire input / output power information including the current value and the voltage value. The input / output power information is obtained based on the current value and the voltage value, the value of the charging power of the battery unit 5, the value of the discharging power of the battery unit 5, the value of the generated power of the power generation device 6, the power conversion unit 3 The power value output from the power system 7 to the power system 7 and the power value input from the power system 7 to the power conversion unit 3 and the load 9 may be included. Furthermore, power consumption information indicating the value of power consumption of the load 9 obtained using a power meter (not shown) or the like may be included in the input / output power information.

  The power charge information acquisition unit 22 acquires power charge information that defines a power charge for each time zone. The electric power charge is a consideration for the use of the power supplied from the commercial power source 8 (that is, commercial AC power) determined by the power company (operating company of the commercial power source 8). In this embodiment, as shown in FIG. 2, it is assumed that a power rate is set. That is, the power charge in the first time zone from 7 o'clock to 10 o'clock on the day, the power charge in the second time zone from 10 o'clock to 17 o'clock on the day, the third from 17:00 to 23 o'clock on the day The power charges in the time zone and the power charges in the fourth time zone from 23:00 on the day to 7:00 on the next day are 13 yen / kWh, 25 yen / kWh, 13 yen / kWh, 10 yen / kWh, respectively. And 13 yen / kWh represents that the charge per 1 kWh (kilowatt hour) of electricity is 13 yen. Any charge in this specification refers to a charge per kWh unless otherwise stated. In this specification, the time is expressed using a 24-hour notation. That is, from midnight to noon is expressed as 0:00 to 12:00, and from noon to 11:59 pm is expressed as 12:00 to 23:59 (0 and 24:00 indicate the same time).

  The power charge information is information representing each power charge in the first to fourth time zones, and the power charge information acquisition unit 22 may receive the power charge information from the power company via the network NET such as the Internet. it can. Alternatively, the operator may use the operation unit 12 to provide power charge information to the acquisition unit 22.

  The charge state management unit 23 sets a charge fee that is a fee required for charging the battery unit 5 using the power charge information. At this time, the charging state management unit 23 can set a charging fee for each of the first to fourth time zones, and also sets a charging fee when charging is performed with the generated power of the power generation device 6. can do.

  As shown in FIG. 3, the charging fee is obtained by adding a predetermined additional fee to the power fee required for charging. The additional charge is generated when supplying the charge power to the battery unit 5 and when the charge conversion value of the loss amount in the power conversion unit 3 and the discharge power of the battery unit 5 are output to the power system 7 or the load 9. And a charge conversion value of the loss amount generated in the power conversion unit 3. Since the charged electric power does not create value until it is discharged, the loss at the time of discharging is included in the additional charge. Charge conversion value for driving power amount of the power conversion unit 3 required when supplying the charging power to the battery unit 5 and power conversion unit required for outputting the discharge power of the battery unit 5 to the power system 7 or the load 9 The charge conversion value of the driving power amount of 3 may be further included in the additional charge.

The additional charge can be given to the charge state management unit 23 as a fixed value in advance based on the loss amount and the drive power amount. The amount of loss and the amount of driving power vary depending on the operating conditions of the power conversion unit 3. For example, the additional charge can be determined using the average value thereof. In the present embodiment, it is assumed that the additional charge is uniformly 4 yen / kWh for all time zones. Then, as shown in FIG. 4 (a), when charging is performed using commercial AC power during the first to fourth time periods, the charging charges are 17 yen / kWh, 29 yen / kWh, 17 yen / kWh, 14 yen / kWh. On the other hand, when charging is performed using the generated power of the power generation device 6, no power charge is incurred, so the charging fee when charging is performed using the generated power of the power generation device 6 in an arbitrary time zone is an additional charge. It coincides with a certain 4 yen / kWh (see FIG. 4B). Hereinafter, charging charges when charging is performed using commercial AC power in the first to fourth time zones are represented by symbols CST _{1 to} CST ₄ , respectively, and charging is performed using the generated power of the power generator 6. The charging charge at that time is represented by the symbol CST ₅ .

In consideration of the fact that the power charges are different among a plurality of time zones, different additional charges may be set for the charging charges CST _{1 to} CST ₄ . That is, for example, the additional charges included in the charging charges CST _{1 to} CST ₄ may be set to 4 yen / kWh, 8 yen / kWh, 4 yen / kWh, 3 yen / kWh, respectively. The charge CST ₅ may be set to a lower charge (that is, less than 3 yen / kWh). Charging fee CST ₅ may be set to 0 yen / kWh.

  The charge state management unit 23 calculates the capacity charged in the battery unit 5 based on the input / output power information, and generates charge state information based on the calculation result. The charge state information holding unit 24 provided in the charge state management unit 23 is a memory that holds (that is, stores) the charge state information. In addition, the term (charge capacity, full charge capacity, remaining capacity, free capacity, dischargeable capacity, etc.) including the word “capacity” described below refers to those of the battery unit 5 unless otherwise specified, and the unit is A · h (ampere · hour) or mA · h (milliampere · hour).

FIG. 5 shows the structure of the charge state information. The plurality of charging charges set by the charging state management unit 23 are referred to as first to nth charging charges for convenience, and the accumulated charge amount of the battery unit 5 due to the charging that requires the first to nth charging charges (that is, the first charging charge). The amount of charge accumulated in the battery unit 5 by charging requiring the 1st to nth charging charges) is referred to as the 1st to nth charging capacity (n is an integer of 2 or more). Any of the above-described charging charges CST _{1 to} CST ₅ is the i-th charging charge. Then, the charge state management unit 23 associates the value of the accumulated charge amount of the battery unit 5 due to the charge requiring the i-th charge fee, that is, the value of the i-th charge capacity, with the i-th charge fee and includes it in the charge state information ( i is an integer of 1 to n. Actually, the charging state management unit 23 can write the value of the i-th charging capacity and the i-th charging fee in the charging state information in association with each other. That is, when the first charge capacity is present in the battery unit 5, the charge state management unit 23 writes the value of the first charge capacity and the first charge charge in association with each other in the charge state information, and the second charge capacity is When the battery unit 5 exists, the value of the second charge capacity and the second charge charge are associated with each other and written in the charge state information. The same applies to the third charging capacity and the third charging fee. Of course, the upper limit of the total of the first to nth charge capacities is the full charge capacity of the battery unit 5.

Figure 6 shows a specific example of the state of charge information at a particular time t _A. Starting from the initial time t _O when the remaining capacity of the battery unit 5 is zero, the battery unit 5 is charged by the charging capacity CC ₄ with commercial AC power in the fourth time zone, and then the power generation device 6 in any time zone. only charge capacity CC ₅ in the generated power is charged battery unit 5, and has been led to the particular time t _a. Symbols CC _{1 to} CC ₄ represent charging capacities charged with charging charges CST _{1 to} CST ₄ , respectively, and symbol CC ₅ represents charging capacities charged with charging charges CST ₅ . Further, it is assumed that the battery unit 5 has not been discharged between the initial time t _O and the specific time t _A , and the sum of the charge capacities CC ₄ and CC ₅ is less than the full charge capacity of the battery unit 5. The management unit 23 calculates the value of the charging capacity CC ₄ based on the input / output power information (specifically, the current value of the power terminal PT ₅ ) during the period when the battery unit 5 is charged with commercial AC power. , the value of the charge capacity CC _4, in association with each other and a charging fee CST ₄ corresponding to the charge capacity CC ₄ writes the charging status information. The management unit 23, the charge capacity CC ₅ and the battery unit 5 in the generated power based on the output power information during being charged (the current value of the specific power terminal PT ₅₎ of the power plant 6 values were calculated, and the value of the charge capacity CC _5, write to each other associated with charging status information and a charging fee CST ₅ corresponding to the charge capacity CC _5. As a result, the charge state information shown in FIG. 6 is generated. Although the value of each charge capacity changes with charging and discharging, the latest charge state information is held in the holding unit 24.

The unit of the value of the charge capacity written in the charge state information may be a unit indicating the capacity itself such as A · h or mA · h, or the ratio of the charge capacity to the full charge capacity of the battery unit 5 It may be written in the charge state information as the value of the charge capacity. In the example shown in FIG. 6, the charge capacities CC ₄ and CC _{5 at} the specific time t _A are 30% and 40% of the full charge capacity, respectively. As a result, the free capacity (the remaining capacity is calculated from the full charge capacity at the specific time t _A. Subtracted capacity) EC is 30% of full charge capacity. Thus, the charge state information indicates values of a plurality of charge capacities in a state where the total charge capacity of the battery unit 5 is divided into a plurality of charge capacities corresponding to a plurality of charge charges.

  The charging / discharging control unit 2 can control charging and discharging of the battery unit 5 based on the input / output power information, the power rate information, and the charging state information. At this time, using the discharge possibility determination unit 25 (see FIG. 1). Thus, the discharge can be controlled. Hereinafter, a plurality of examples including the operation description of the discharge possibility determination unit 25 will be described. As long as there is no contradiction, it is possible to combine any two or more embodiments among a plurality of embodiments.

<< First Example >>
A first embodiment of the battery system 1 will be described. FIG. 7 is an operation flowchart of the battery system 1 according to the first embodiment, particularly focusing on the operation of the charge / discharge control unit 2.

  When the battery system 1 is activated, first, in step S11, the power charge information acquisition unit 22 acquires power charge information as shown in FIG. In subsequent step S12, the charge / discharge control unit 2 determines whether or not the current time belongs to a predetermined charge permission time zone. If the current time belongs to the charge permission time zone, the charge / discharge control unit 2 performs step S12 to step S21. On the other hand, if not, the process proceeds from step S12 to step S31. The charging / discharging control unit 2 or the operator can set the charging permission time zone in advance, and it is preferable to include at least the fourth time zone, which is the time zone with the lowest power charge, in the charging permission time zone. (See FIG. 2). Here, it is assumed that the charging permission time zone coincides with the fourth time zone (the same applies to other examples described later). Then, as will be understood from FIG. 7 and the following description, in the first embodiment, discharging is not performed in the fourth time zone, and only charging can be performed.

The operation when the transition from step S12 to step S21 is performed will be described. In step S21, the charge / discharge control unit 2 determines whether or not the battery unit 5 is in a chargeable state based on the charge state information and the like. Only when it determines with the battery part 5 being in the state which can be charged, it transfers to step S22 from step S21, and when that is not right, it returns to step S11 from step S21. For example, when the SOC (state of charge) of the battery unit 5 is greater than or equal to a predetermined value LIM _SOCUP, or when some abnormality (overcharge, abnormally high temperature, etc.) occurs in the battery unit 5, the battery unit 5 is charged. It is determined that the battery unit 5 is in an incapable state. Otherwise, it is determined that the battery unit 5 is in a chargeable state. As is well known, the SOC is a ratio of the remaining capacity of the battery unit 5 to the full charge capacity of the battery unit 5. When charging up to a fully charged state with commercial AC power is permitted, LIM _SOCUP may be set to 1. In the case where the remaining charging capacity by the power generated by the power generation device 6 is left, a value less than 1 and 0 or more may be set in the LIM _SOCUP . However, in this case, if it is determined that there is surplus power generation in step S31, which will be described later, in order to perform charging up to the fully charged state with surplus power generation, if step S21 is reached, LIM _SOCUP is forcibly set to 1. Substitution is good.

In step S <b> 22, the charging state management unit 23 sets a charging fee required for charging to be performed. That is, when charging with commercial AC power, the charging fee is obtained by adding the above-mentioned additional fee to the power fee for the current time zone. If charging at commercial AC power when the charging permitted period is limited to a fourth time period, the charging fee set at step S22 is charging fee CST ₄ (see Figure 4 (a)). When charging is performed with the generated power of the power generation device 6, the charging fee set in step S22 is the charging fee CST ₅ (see FIG. 4B).

After step S22, in step S23, the charge / discharge control unit 2 starts charging the battery unit 5 by instructing the power conversion unit 3 to start charging. After charging is started in step S23, the processes in steps S24 and S25 are repeatedly executed during the charging period until charging is stopped in step S26. In step S24, the charge state management unit 23 based on the output power information in (current value of the specific power terminal PT _5), slide into sequentially updated and the state of charge information to the latest one.

Specifically, for example, a start is the time a particular time t _A charged at step S23, and the charge amount 8% of the full charge capacity at between time t _A and t _B1 is band 4 hours As shown in FIG. 8A, the charging capacity CC ₄ , the charging capacity CC ₅ and the free capacity EC of the charging state information are full at time t _B1 , respectively. It will be 38%, 40% and 22% of the charge capacity (the above update will be made to do so). Alternatively, for example, a time specific time t _A charging has been started in step S23, and the charge amount of 7% fraction of the full charge capacity at between time t _A and t _B2 is the generated power of the generator 6 When the battery unit 5 is charged, as shown in FIG. 8B, the values of the charge capacity CC ₄ , the charge capacity CC ₅ and the free capacity EC of the charge state information at time t _B2 are the full charge capacity, respectively. 30%, 47%, and 23% (the above update is made to do so). Here, it is assumed that the times t _B1 and t _B2 are times between the specific time t _A and the time when charging stops in step S26.

In step S25 following step S24, the charge / discharge control unit 2 checks whether or not a charge stop factor has occurred. When a charge stop factor occurs, a transition from step S25 to step S26 occurs, and in step S26, the charge / discharge control unit 2 instructs the power conversion unit 3 to stop charging, whereby the battery unit 5 Is stopped, and then the process returns to step S11. If no charge stop factor has occurred in step S25, the process returns from step S25 to step S24 and charging is continued. For example, when charging is performed with a commercial AC power source, when the SOC of the battery unit 5 is equal to or higher than a predetermined value LIM _SOCUP , when the charging is performed with the generated power of the power generation device 6, the surplus of the power generation device 6 When the power is consumed, when the power charge applied at the current time is changed from the power charge applied at the start of charging, or when some abnormality occurs in the battery unit 5, a charging stop factor has occurred. To be judged.

  Next, an operation when the transition from step S12 to step S31 is performed will be described. In step S <b> 31, the charge / discharge control unit 2 determines whether there is currently surplus power in the generated power of the power generation device 6. When there is surplus power, the process proceeds from step S31 to step S21, and the above-described step S21 and subsequent processing are executed. On the other hand, when there is no surplus power, the process proceeds from step S31 to step S32. When the load 9 is driven only by the power generated by the power generation device 6, surplus power is obtained by subtracting the power used for driving the load 9 from the total power generated by the power generation device 6. For example, the charge / discharge control unit 2 can determine the presence or absence of surplus power based on the current power consumption of the load 9 and the current power generation of the power generation device 6. For this determination, input / output power information including the value of the generated power of the power generation device 6 and the value of the power consumption of the load 9 may be used.

  In step S <b> 32, the discharge availability determination unit 25 executes a discharge availability determination process. The timing at which the discharge propriety determination process is performed is referred to as determination timing. The discharge permission / inhibition determination process is a process for determining whether to permit discharging of the battery unit 5 after the determination timing based on the power rate information and the charge state information at the determination timing. More specifically, in the discharge propriety determination process, the discharge propriety determination unit 25 has a battery unit that has a charge capacity (hereinafter referred to as a low-cost charge capacity) corresponding to a charge lower than the power charge in the time zone to which the determination timing belongs. 5 is determined based on the power charge information and the charge state information at the determination timing. Then, when the existence is not recognized (that is, when the existence of the low cost charging capacity is not indicated in the charging state information), the process returns from step S32 to step S11, but when the existence is recognized (that is, In the case where the existence of the low-cost charge capacity is indicated in the charge state information), the transition from step S32 to step S33 occurs, and the dischargeable capacity is set based on the low-cost charge capacity in step S33.

For example, if reached to step S32 in certain time _{t A,} the specific time _{t A} a determination timing. In this case, if the specific time t _A belongs to the third time zone, the charging fee CST ₄ (14 yen / kWh) is high and the charging fee in comparison with the power fee (13 yen / kWh) in the third time zone. Since CST ₅ (4 yen / kWh) is low, only the charge capacity CC ₅ is a low-cost charge capacity. Or, for example, if the specific time t _A as the determination timing belongs to the second time zone, the charge charges CST ₄ (14 yen / kWh) and CST ₅ (4 yen / kWh) are both the power charges for the second time zone ( Therefore, the total capacity of the charge capacities CC ₄ and CC ₅ (that is, 70% of the full charge capacity) is the low cost charge capacity.

  In step S33, the discharge possibility determination unit 25 sets the low-cost charge capacity to the dischargeable capacity. However, in step S33, the discharge possibility determination unit 25 determines the capacity less than the low-cost charge capacity (for example, the capacity obtained by multiplying the low-cost charge capacity by a predetermined value less than 1 or the predetermined capacity from the low-cost charge capacity. A small capacity) may be set as a dischargeable capacity.

  In step S <b> 34 subsequent to step S <b> 33, the charge / discharge control unit 2 instructs the power conversion unit 3 to start discharging to start discharging the battery unit 5. The dischargeable capacity is a capacity in which discharge of the battery unit 5 is permitted, and the total capacity discharged from the battery unit 5 after the start of discharge in step S34 (that is, from the battery unit 5 after the start of discharge in step S34). It is prohibited that the capacity conversion value of the output electric power) exceeds the dischargeable capacity set in step S33 (this prohibition is realized in steps S36 and S37 described later). That is, the discharge possibility determination unit 25 permits the discharge of the battery unit 5 with the dischargeable capacity as a limit. If the low-cost charge capacity is 40% of the full charge capacity and the low-cost charge capacity itself is set to the dischargeable capacity in step S33, the battery unit 5 is limited to 40% of the full charge capacity. Discharge is allowed.

After the discharge is started in step S34, the processes in steps S35 and S36 are repeatedly executed during the discharge period until the discharge is stopped in step S37. In step S35, the charge state management unit 23 performs the discharge. based on the output power information during (current value of the specific power terminal PT _5), slide into sequentially updated state of charge information to date. A specific example of this update will be described later.

In step S35, the charge / discharge control unit 2 (for example, the discharge possibility determination unit 25) also updates the dischargeable capacity. That is, if the dischargeable capacity set in step S33 is Q _INT and the total capacity discharged from the battery unit 5 after the start of discharge in step S34 is Q, the value of the dischargeable capacity is (Q _INT- Q).

  In step S36 following step S35, the charge / discharge control unit 2 checks whether or not a discharge stop factor has occurred. When a discharge stop factor has occurred, a transition from step S36 to step S37 occurs, and in step S37, the charge / discharge control unit 2 instructs the power conversion unit 3 to stop discharging, whereby the battery unit 5 Then, the process returns to step S11. If no discharge stop factor has occurred in step S36, the process returns from step S36 to step S35 to continue the discharge. For example, when the dischargeable capacity becomes zero, the power charge applied at the current time is changed from the power charge applied at the start of discharge, or when any abnormality occurs in the battery unit 5, the discharge is performed. It is determined that a stop factor has occurred.

  In the operation of FIG. 7, the discharge of the battery unit 5 is controlled using charge state information including a plurality of charge capacity values corresponding to a plurality of charge charges and power charge information. With this control, it is possible to accurately determine whether economical discharge can be performed in comparison with the current power rate, and as a result, truly economical discharge control can be realized.

  Specifically, it is possible to determine whether or not a truly economical discharge can be performed by executing the discharge possibility determination process (step S32) based on the power rate information and the charge state information. In the operation of FIG. 7, when the existence of a low-cost charge capacity is recognized as a result of the determination, a dischargeable capacity is set from the low-cost charge capacity, and discharge is permitted with the dischargeable capacity as a limit. As a result, discharge is always performed using a charge capacity (that is, a low-cost charge capacity) at a charge lower than the current power charge, so that a truly economical discharge can be performed.

  In addition, it is difficult to perform a truly economical discharge by a method using an average value of power charges at the time of charging (hereinafter referred to as an average value method). For example, when charging is performed for 30% of the full charge capacity when the power rate is 10 yen / kWh and 20 yen / kWh, the average value is 15 yen / kWh. In this case, if the current power rate is 17 yen / kWh, the average value is lower than the current power rate, so the average value method permits discharging of the full charge capacity. However, since 30% of the full charge capacity is charged with a power charge of 20 yen / kWh, the discharge for the charge charged with a power charge of 20 yen / kWh is economical. Not right. This is because it is cheaper to purchase electricity of 17 yen / kWh than to discharge.

  In this embodiment, the concept of an additional charge (see FIG. 3) is introduced, and a method of setting each charging charge through addition of the additional charge is adopted. For this reason, it is possible to know the true cost of charging and discharging including the loss cost in the power conversion unit 3, and as a result, it is possible to perform truly economical charge / discharge control. However, the addition of the additional fee is arbitrary, and the additional fee can be set to zero.

  Next, first to fourth update methods will be individually described as update methods of the charge state information during discharging. When there is only one low-cost charge capacity in the charge state information, the management unit 23 can use the first update method. When there are two or more low-cost charge capacities in the charge state information, the management unit 23 can use any one of the second to fourth update methods.

The first update method will be described. The management unit 23 using the first update method decreases the value of the low-cost charge capacity included in the charge state information by one amount corresponding to the discharged capacity. That is, for example, the time at which the discharge is started in step S34 is the specific time t _A , the specific time t _A belongs to the third time zone, and the battery is fully charged between the times t _A and t _C1. When the charge amount corresponding to 5% of the capacity is discharged, the management unit 23 decreases the value of the charge capacity CC ₅ that is the low-cost charge capacity by 5% of the full charge capacity between the times t _A and t _C1 . . As a result, as shown in FIG. 9, the values of the charge capacity CC ₄ , the charge capacity CC ₅ and the free capacity EC in the charge state information at time t _C1 are 30%, 35% and 35% of the full charge capacity, respectively ( The above update is made so that it becomes). Time t _C1 and time t _{C2, which} will be described later, are times between the specific time t _A and the time at which charging stops in step S37.

The second update method will be described. As described above, the second update method can be used when there are two or more low-cost charge capacities. Management unit 23 using the second update method, with the discharge, among a plurality of low-cost charging capacity, executes the update processing J _A to reduce the value of the charging capacity corresponding to a lower charging fee preferentially.

A third update method will be described. Management unit 23 using the third update method, with the discharge, among a plurality of low-cost charging capacity, executes the update process J _B to reduce the value of the charging capacity corresponding to the higher charge rates priority.

A fourth update method will be described. Management unit 23 using the fourth update method, with the discharge, to perform updates J _C to reduce the value of a plurality of low cost charge capacity at the same time. In the update process _JC , for example, a plurality of low-cost charge capacity values can be evenly reduced. Since the values decreased by the update processes J _A , J _B and J _C are values in the charge state information, it can be said that the update processes J _A , J _B and J _C are update processes for the charge state information.

As a specific example, it is assumed that the time at which the discharge is started in step S34 is the specific time t _A and the specific time t _A belongs to the second time zone. In this case, the charge capacities CC ₄ and CC ₅ are both low-cost charge capacities, and the charge capacity CC ₅ corresponds to a lower charge rate than the charge capacity CC ₄ . In this case, when the charge amount 8% of the full charge capacity is discharged in between times _{t A} and _{t C2,} management unit 23 to perform the update processing _{J A,} in between time _{t A} and _{t C2,} more The management unit 23 that executes the update process J _B by reducing the value of the charge capacity corresponding to the low charge rate, that is, the value of the charge capacity CC ₅ by 8% of the full charge capacity (see FIG. 10A), in between time t _a and t _C2, the value of the charging capacity corresponding to the higher charge rates, i.e. to reduce the value of the charge capacity CC ₄ by 8% of the fully-charged capacity (see FIG. 10 (b)), the update process management unit 23 to perform a J _C, in between time t _a and t _C2, charging such that the sum of the amount of decrease in the magnitude of the value of the charge capacity CC ₄ and CC ₅ of 8% of the full charge capacity capacity CC ₄ and CC ₅ values simultaneously (e.g. evenly) So little of (see FIG. 10 (c)).
As a result, the values of the charge capacity CC ₄ , the charge capacity CC ₅ and the free capacity EC of the charge state information at time t _C2 are as shown in FIG. 10A if the second update method (update process J _A ) is used. , 30%, 32% and 38% of the full charge capacity, respectively, and if the third update method (update process J _B ) is used, 22% of the full charge capacity, respectively, as shown in FIG. If the fourth update method (update process J _C ) is used, for example, as shown in FIG. 10C, the full charge capacity is 26%, 36%, and 38%, respectively.

Under the above assumption that the specific time t _A belongs to the second time zone, when using the second update method (see FIG. 10A), by discharging compared to buying commercial AC power, 1 kWh Electricity costs will increase by 21 yen (= 25 yen-4 yen) per hit. That is, a power cost reduction effect of 21 yen can be obtained (advantageous). However, there is a demerit that the low-cost charge capacity does not exist when the discharge for all of the charge capacity CC ₅ minutes is completed and the third time period is reached, so that the discharge cannot be used in the third time period.

On the other hand, under the above assumption that the specific time t _A belongs to the second time zone, when the third update method is used (see FIG. 10B), the discharge is performed compared to the case where commercial AC power is purchased. Although it is calculated that the power cost is increased by 11 yen per kWh (= 25 yen-14 yen), this power cost reduction effect is small in comparison with the second update method (that is, comparison with the second update method). Has disadvantages). However, even when the discharge of the charge capacity CC ₄ minutes is completed and the third time zone is reached, the charge capacity CC ₅ still remains, so the discharge can be continued even in the third time zone (this point). , There are benefits). However, since such a continuation is possible, the depth of discharge increases, which is disadvantageous for extending the life of the battery unit 5.

As described above, each of the second and third update methods has advantages and disadvantages. The fourth update method is intermediate between the second and third update methods and may not be realized by the charge / discharge control unit 2. Which of the second to fourth update methods is adopted (that is, which of update processes J _A , J _B and J _C is executed), or which of the second and third update methods is adopted ( In other words, the charge / discharge control unit 2 can be formed so that the update process J _A or J _B can be freely selected. That is, it is preferable to provide an update process selection unit 26 (see FIG. 11) for making this selection in the charge / discharge control unit 2. When there are a plurality of low-cost charge capacities, the selection unit 26 selects any one of the update processes J _A , J _B and J _C as the update process of the charge state information associated with the discharge, or the update process J _A or selecting the J _B as updating of the state of charge information associated with a discharge. The selection unit 26 may perform this selection in accordance with an instruction from the operator (an instruction made by the operator to the operation unit 12). Thereby, the driving | operation along with an operator's hope is achieved.

Alternatively, the selection unit 26 may perform this selection based on various indexes regardless of the operator's instruction. For example, if the degree of deterioration of the battery unit 5 is equal to or greater than a predetermined reference value, the selection unit 26 is expected to perform an update process J _A that is expected to have a small depth of discharge and a relatively moderate degree of deterioration of the battery unit 5. and to choose as the updating of the state of charge information associated with the discharge, if not, may be the update process J _B or J _C is selected as the update process of the state of charge information associated with a discharge. For example, the selection unit 26 obtains the ratio of the current full charge capacity of the battery unit 5 to the initial full charge capacity (rated capacity, etc.) of the battery unit 5 as SOH (state of health), and 1 / SOH is obtained from the battery unit 5. It can be used as the degree of deterioration of By such selection selection of update processing, optimal update processing is performed according to the state of the battery unit 5.

<< Second Example >>
A second embodiment of the battery system 1 will be described. The second embodiment and the third embodiment to be described later are embodiments in which a part of the first embodiment is modified, and there is no contradiction regarding matters not particularly mentioned in the description of the second and third embodiments. As long as the description in the description of the first embodiment applies to the second and third embodiments.

As shown in FIG. 12, the charge / discharge control unit 2 predicts the generated power amount of the power generation device 6 during the future prediction period from the current time, and the future prediction period from the current time. A power consumption amount prediction unit 28 for predicting the power consumption amount of the load 9 in the inside can be provided. The power generation amount and the power consumption amount predicted by the prediction units 27 and 28 are hereinafter referred to as a predicted power generation amount GE _EST and a predicted power consumption amount CO _EST . The predicted power generation amount GE _EST is a predicted value of the total power generation amount during the prediction period, and the predicted power consumption amount CO _EST is a predicted value of the total power consumption amount during the prediction period. The prediction period is an arbitrary period in the future from the timing of performing the prediction, and the time length is also arbitrary.

The generated power amount prediction unit 27 predicts the generated power based on, for example, forecast data obtained from a server (not shown) via the network NET, historical information on the past generated power amount of the power generation device 6, or a combination thereof. The quantity GE _EST can be determined. The past refers to a time before the timing when the prediction unit 27 performs prediction. As described above, since the power generation device 6 is assumed to be a solar power generation device in the present embodiment, the forecast data includes, for example, forecast contents such as weather, sunshine hours, and temperature during the forecast period. It is good to be. In addition, the electric energy GE _EST can be obtained by using a known prediction method (for example, the prediction method described in Japanese Unexamined Patent Application Publication No. 2008-021152 or Japanese Unexamined Patent Application Publication No. 2007-184354).

The power consumption amount prediction unit 28 is based on the history information of the past power consumption amount of the load 9 (information holding the past history of the power consumption information described above), the driving schedule of the load 9, or a combination thereof. The predicted power consumption CO _EST can be obtained. The drive schedule of the load 9 specifies, for example, how long the load 9 is driven during the prediction period (how many hours the power is consumed), and the specific contents and the power required for driving the load 9 The electric energy CO _EST can be obtained using the value of. It is assumed that the driving schedule is known to the prediction unit 28. When the load 9 is an electric device such as a public hall, a driving schedule can be obtained from the use reservation status of the public hall.

Even when the predicted power consumption CO _EST is larger than the predicted power generation amount GE _EST , the charge / discharge control unit 2 can permit discharge by the method described in the first embodiment. However, the charge / discharge control unit 2 according to the second embodiment, when the predicted power consumption CO _EST in the time zone in which the power rate is relatively high is larger than the predicted power generation amount GE _EST , the difference amount (CO _EST charge capacity corresponding to -GE _EST) to set the discharge capacity so as to leave.

  FIG. 13 is an operation flowchart of the battery system 1 that realizes such setting. In FIG. 13, step S33 is changed to step S33a on the basis of the operation flowchart of FIG. 7, and the processing of each step of FIGS. 7 and 13 is the same except for the change. Therefore, only the process of step S33a will be described. In the second embodiment, step S33a is executed instead of step S33. That is, when it is recognized in step S32 that the low-cost charge capacity is present in the total charge capacity of the battery unit 5, the process proceeds from step S32 to step S33a. When the description of the first embodiment is applied to the second embodiment, the symbol “S33” in the description of the first embodiment is replaced with the symbol “S33a” in the second embodiment.

In step S33a, the prediction unit 27 and 28, predicts the amount of power generation and the power consumption in the prediction period in P _A containing the time zone in which the power rate is relatively high, whereby the power during the forecast period P _A The quantities GE _EST and CO _EST are obtained as the electric energy GE _EST [P _A ] and CO _EST [P _A ], respectively.

In step S33a, the discharge possibility determination unit 25 determines whether the first inequality “(CO _EST [P _A ] −GE _EST [P _A ])> 0” is satisfied. When the first inequality is not established, the discharge possibility determination unit 25 sets the dischargeable capacity based only on the low-cost charge capacity as in the first embodiment, but when the first inequality is established, The dischargeable capacity is set based on the low-cost charge capacity and the difference amount (CO _EST [P _A ] −GE _EST [P _A ]). Specifically, when the first inequality is satisfied, in step S33a, the discharge possibility determination unit 25 corresponds to a capacity corresponding to a difference amount (CO _EST [P _A ] −GE _EST [P _A ]) from a low cost charge capacity. The capacity value that is as small as possible is set to the value of the dischargeable capacity. If, low cost charging capacity is a 40% of full charge capacity, and, when the capacity corresponding to the difference amount _{(CO EST [P A] -GE} EST [P A]) is 10% of the full charge capacity Therefore, from 40% -10% = 30%, 30% of the full charge capacity can be set as the dischargeable capacity. After setting the dischargeable capacity, the processes of steps S34 to S37 are executed as in the first embodiment.

If the amount of power consumption is predicted to exceed the amount of generated power during a time period when the future power rate will increase, in step S33a, the above difference amount is secured for the purpose of suppressing power purchase in that time period. Keep it. This gist forecast period P _A comprises a current time time zone higher power rate than the power charge for the time period that belongs (processing time for performing the step S33a) is applied, the power of the time zone to which the current time belongs It does not include the time period when the lower electricity rate is applied. Thus, for example, if the current time (time of performing the process of step S33a) that belongs to the first time zone, but the forecast period P _A comprises the second time zone not including the fourth time period (typically, for example the prediction period P _a it is sufficient to match the second time zone).

  According to the second embodiment, when it is predicted that the amount of power consumption will exceed the amount of generated power during the time period when the future power rate is high, the dischargeable capacity is ensured with the charge capacity for the difference amount between them. Is set. For this reason, the power purchase in the time slot | zone when a future electric power charge becomes high is suppressed, and more economical charge / discharge control is implement | achieved.

<< Third Example >>
A third embodiment of the battery system 1 will be described. Also in the third embodiment, the prediction units 27 and 28 described in the second embodiment are used, and the items described in the second embodiment are applied to the third embodiment as long as there is no contradiction.

  The control for the power converter 3 (charge / discharge circuit) by the charge / discharge controller 2 includes basic charge control. The basic charging control is the control for charging the battery unit 5 in the charging permission time zone (for example, the fourth time zone, which is the time zone with the lowest power charge) described in the first embodiment. It is. As a result, charging can be performed as economically as possible. In the first embodiment in which the basic charging control itself is executed, discharging is not permitted during the charging permission time period.

However, the third embodiment according to the example charging and discharging control unit 2 (such as the discharge determination unit 25), the predicted power generation amount _{GE EST} is greater than the predicted consumed electric power amount _{CO EST,} and their power difference amount _{(GE EST} -CO _EST ) is larger than the amount of power corresponding to the free space EC, even if the current time (for example, the predicted time) belongs to the charge permission time zone, the execution of the basic charge control is stopped. The dischargeable capacity is set based on the difference power amount (GE _EST -CO _EST ) and the free capacity EC, and discharge of the battery unit 5 is permitted with the dischargeable capacity as a limit. If the prediction is correct and surplus power exceeding the free space EC (GE _EST -CO _EST ) occurs in the future, charging can be performed with the surplus power in the future. This is because it is more economical.

  In order to realize such discharge permission, the operation flowchart of the battery system 1 of the third embodiment is modified from FIG. 7 to FIG. 14 of the first embodiment. In FIG. 14, steps S12 and S33 are changed to steps S12b and S33b, respectively, based on the operation flowchart of FIG. 7, and the processing of each step of FIGS. 7 and 14 is the same except for the change. When the description of the first embodiment is applied to the third embodiment, the symbols “S12” and “S33” in the description of the first embodiment are replaced with the symbols “S12b” and “S33b” in the third embodiment. .

Although not shown in FIG. 14, the prediction units 27 and 28 can predict the generated power amount and the consumed power amount periodically or at an arbitrary timing. In step S12b following step S11, the predicted power generation amount GE _EST [P _B ] and the predicted power consumption amount CO _EST [P _B ], which are the power amount GE _EST and CO _EST during the prediction period P _B , are used. The prediction period P _B may include any time period from the first to fourth time periods. The prediction period P _B is a period having a time length of one day starting from the time point when the process of step S12b is performed, for example.

In step S < _b > 12 _b , the charge / discharge control unit 2 only applies when the current time belongs to the charge permission time zone and the second inequality “GE _EST [P _B ] −CO _EST [P _B ] ≦ POW _EC ” is satisfied. The transition from step S12b to step S21 is executed. If not, the transition from step S12b to step S31 is executed. Therefore, when “GE _EST [P _B ] −CO _EST [P _B ] −POW _EC > 0” is satisfied, even if the current time belongs to the fourth time zone, the execution of the basic charge control is stopped (ie, step (Transition to S21 is prohibited). POW _EC is the amount of power corresponding to the free capacity EC at the current time (for example, the product of the free capacity EC and the rated output voltage of the battery unit 5). It may be considered that the current time is a timing for predicting the electric energy GE _EST [P _B ] and CO _EST [P _B ]. When the process proceeds from step S12b to step S21, a value corresponding to “1-K (GE _EST [P _B ] −CO _EST [P _B ])” may be set in the above-described LIM _SOCUP in step S21 (however, , LIM _{SOCUP has} an upper limit of 1). K (GE _EST [P _B ] −CO _EST [P _B ]) is an SOC conversion value of the electric energy (GE _EST [P _B ] −CO _EST [P _B ]), and K is the value of the electric energy in the SOC It is a coefficient for converting to the value of. After the transition from step S12b to step S31, the processes of steps S31 and S32 are performed as in the first embodiment, and it is recognized that the low-cost charge capacity exists in the total charge capacity of the battery unit 5 in step S32. If it is found, the process proceeds from step S32 to step S33b.

In step S33b, the discharge possibility determination unit 25 determines the dischargeable capacity based on the amount of power (GE _EST [P _B ] −CO _EST [P _B ] −POW _EC ) while considering the low-cost charge capacity as necessary. Set. Specifically, for example, the discharge possibility determination unit 25 can set a capacity corresponding to the electric energy (GE _EST [P _B ] −CO _EST [P _B ] −POW _EC ) as a dischargeable capacity. However, if the capacity corresponding to the amount of electric power (GE _EST [P _B ] −CO _EST [P _B ] −POW _EC ) is larger than the low cost charge capacity, the discharge possibility determination unit 25 discharges the low cost charge capacity. It may be set to a possible capacity. The upper limit of the dischargeable capacity set in step S33b is naturally the total charge capacity of the battery unit 5. After setting the dischargeable capacity, the processes of steps S34 to S37 are executed as in the first embodiment.

If the inequality “GE _EST [P _B ] −CO _EST [P _B ] −POW _EC > 0” is satisfied and the process reaches Steps S31 and S32, it is unconditional regardless of the presence or absence of the low-cost charge capacity. Then, the transition from step S32 to step S33b may be permitted, and the capacity corresponding to the electric energy (GE _EST [P _B ] −CO _EST [P _B ] −POW _EC ) may be set as the dischargeable capacity.

<< Deformation, etc. >>
The embodiment of the present invention can be appropriately modified in various ways within the scope of the technical idea shown in the claims. The above embodiment is merely an example of the embodiment of the present invention, and the meaning of the term of the present invention or each constituent element is not limited to that described in the above embodiment. The specific numerical values shown in the above description are merely examples, and as a matter of course, they can be changed to various numerical values. As annotations applicable to the above-described embodiment, notes 1 to 4 are described below. The contents described in each comment can be arbitrarily combined as long as there is no contradiction.

[Note 1]
The present invention is particularly useful when the power generated by the power generation device 6 cannot be sold, the power sale fee is lower than the power purchase fee, or the private consumption fee of the power generation device 6 is higher than the power sale fee. It is. When the generated power of the power generator 6 is consumed by a load 9 (load in a factory or a general house where the battery system 1 is introduced) for the spread of the power generator 6, etc., to the user or owner of the power generator 6 The method of granting money is being considered in several countries. The self-consumption fee refers to the money in the method.

[Note 2]
In the above-described embodiment, 24 hours are divided into four time zones (first to fourth time zones), but any number of time zones to which different power charges are applied may be any number as long as it is two or more. .

[Note 3]
In the above-described embodiment, a total of five charging charges CST _{1 to} CST ₅ can be set. However, the number of charging charges set by the management unit 23 may be any number as long as it is two or more (for example, the charging charge CST Only ₄ and CST ₅ may be set).

[Note 4]
The charge / discharge control unit 2 can be configured by hardware or a combination of hardware and software. A function realized using software may be described as a program, and the function may be realized by executing the program on a program execution device (for example, a computer). Specifically, for example, by providing a CPU (Central Processing Unit) in the charge / discharge control unit 2 and causing the CPU to execute a program stored in a flash memory (not shown), a necessary function can be realized. .

DESCRIPTION OF SYMBOLS 1 Battery system 2 Charging / discharging control part 3 Power conversion part 5 Battery part 6 Power generation device 7 Electric power system 8 Commercial power supply 9 Load 22 Electricity rate information acquisition part 23 Charging state management part 26 Update process selection part 27 Power generation electric energy estimation part 28 Consumption Electricity prediction unit

Claims (5)

A charge / discharge circuit for charging and discharging the battery unit;
A charge / discharge control unit that controls charging and discharging of the battery unit by controlling the charge / discharge circuit;
The charge / discharge control unit
A power rate information acquisition unit that acquires power rate information representing the power rate of the supply power of the commercial power supply for a plurality of time zones;
A plurality of charging charges required for charging the battery unit is set using the power charge information, and the plurality of charging units are divided into a plurality of charging capacities corresponding to the plurality of charging charges. A charge state management unit that holds charge state information indicating a value of the charge capacity ,
Determining whether to permit discharging of the battery unit after the determination timing based on the power rate information and the charging state information at the determination timing;
When the charge state information indicates the presence of a charge capacity corresponding to a charge lower than the power charge in the time zone to which the determination timing belongs, the dischargeable capacity is set based on the charge capacity corresponding to the low charge charge Then, discharging and discharging of the battery unit is permitted with the dischargeable capacity as a limit . The charging state management unit sets each charging fee using the power supplied from the commercial power source by adding a predetermined fee to the power fee for each time period based on the power fee information. The charge / discharge control apparatus according to claim 1. In addition to the battery unit, the charge / discharge circuit is connected to a power generation device that generates power and outputs generated power and a load that consumes power,
The charge / discharge control unit further includes a prediction unit that predicts the power generation amount of the power generation device and the power consumption amount of the load in the future, and the predicted power consumption amount by the prediction unit is larger than the predicted power generation amount When permitting the discharge of the battery unit in, the charging capacity corresponding to a charging charge lower than the power charge of the time zone to which the determination timing belongs, the difference between the predicted power consumption and the predicted power generation amount, The dischargeable capacity is set based on
The charge / discharge control apparatus according to claim 1 or 2 , wherein When the charge state information indicates the presence of two or more charge capacities corresponding to two or more charge charges lower than a power charge in a time zone to which the determination timing belongs,
With respect to the state of charge information along with the discharge of the battery unit,
A first process for preferentially reducing a value of a charge capacity corresponding to a lower charge charge among the two or more charge capacity;
A second process for preferentially reducing the value of the charge capacity corresponding to a higher charge charge among the two or more charge capacity; or
A third process for simultaneously reducing the values of the two or more charge capacities is executed.
The charge / discharge control apparatus according to any one of claims 1 to 3 . The charge / discharge control unit further includes a selection unit that selects which of the first to third processes is to be executed, or which of the first and second processes is to be executed.
The charge / discharge control apparatus according to claim 4 .

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