JP2008306832A - Power storage system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power storage system capable of surely performing the peak-cut operation while suppressing the capacity of a battery device. <P>SOLUTION: A power facility 1 includes a power receiving facility 2, loads 3A, 3B, 3C and a power storage system 4. The power storage system 4, including a battery device 5 and a controller 6, is charged by a commercial electric power and has a function to supply electric power to the loads 3A, 3B, 3C. The charging/discharging control unit 61 of the controller 6 performs first control for switching so as to charge a secondary battery 52 in a night power time zone while to discharge from the secondary battery 52 in a day power peak time zone. Furthermore, the charging/discharging control unit 61 performs second control to allow the battery device 5 to execute a charging operation when the discharging operation by the battery device 5 is not required in the peak time zone and the battery device 5 is not fully charged. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power storage system applied to a power consumer in which a power storage device is introduced in order to achieve power peak cut.

  In recent years, there are cases where a power storage device is introduced in a power consumer mainly for the purpose of reducing power charges. This power storage device includes a storage battery that can be charged and discharged, charges the storage battery with inexpensive nighttime power, and discharges it in the daytime to carry a part of the load. For example, Patent Document 1 discloses a system in which power is supplied from a power storage device to a load during a peak time period from 11:00 to 15:00 in summer, and the power storage device is charged during other time zones. .

With the introduction of this power storage device, power consumers are not only able to reduce the pay-as-you-go fee by partly supplying daytime electricity with nighttime electricity, but also the annual amount of electricity used during the summer season. The benefits of reducing the basic charge (contract charge) by reducing the maximum peak power level (so-called peak cut) can be enjoyed. On the other hand, there is also an advantage for electric power companies that, ultimately, cut-off of the peak can suppress investment in power plant construction and enhancement.
JP 2006-230147 A

  However, if the system is such that the power storage device is charged only during the night power hours, the following problems arise. First, it is necessary to provide the power storage device with a discharge capacity that corresponds to the total load amount that is assumed to exceed the contract power during the peak time period. This leads to a demand for an increase in capacity of the power storage device. In general, the operation cost increases in proportion to the capacity of the power storage device. As a result, the increase in capacity of the power storage device reduces the merits of introducing the power storage device as a power consumer. .

  In addition, it is no longer possible to deal with unexpected power demands that exceed the contracted power after the storage device has been discharged and the remaining capacity has been exhausted. This can boost the level of maximum peak power. For high-voltage power consumers, a system in which the power contract fee is determined based on the maximum peak power level over the past year is generally adopted. Despite the introduction of the power storage device, a sufficient peak cut effect cannot be enjoyed.

  This invention is made | formed in view of said situation, and it aims at providing the electric power storage system which can perform a peak cut reliably, suppressing the capacity | capacitance of an electrical storage apparatus.

  An electric power storage system according to one aspect of the present invention is an electric power storage system applied to a consumer who receives power from a commercial power system and supplies electric power to a load. A power storage device capable of discharging power and supplying power to the load; and a control device for controlling a charge / discharge operation of the power storage device, wherein the control device has a predetermined first time zone. A time zone for causing the power storage device to perform a charging operation is assigned, and a second time zone different from the first time zone is assigned as a time zone for causing the power storage device to perform a discharging operation, and is required within each time zone. In a first control for performing a charging operation or a discharging operation for a period of time, and in a peak time zone set in advance in the second time zone, a discharging operation by the power storage device is not required, and Charge There if below a predetermined first threshold value, and a second control for causing the charging operation to the power storage device, characterized in that it is capable of execution (claim 1). The first time zone is preferably a night power time zone.

  According to this configuration, the power storage device is charged in the first time zone (for example, the nighttime power time zone), and the power storage device is discharged in the second time zone (for example, the daytime time zone) as necessary. The control to be performed is executed as the first control. In addition to this, the charging operation of the power storage device is also performed in a time zone that does not require a discharge operation in the peak time zone within the second time zone (second control). That is, the power storage device is charged not only in the nighttime power hours but also when there is a margin in power demand in the peak hours. Therefore, it is possible to suppress the capacity of the power storage device as much as possible, and to cope with unexpected power demand.

  In the above configuration, it is desirable that the second control is executed when the power storage device is not fully charged (Claim 3). According to this configuration, since there is a margin for power demand in the peak time period and the charging operation is performed when the power storage device is not in a fully charged state, the power storage device can be maintained as close to full charge as possible. Become.

  In the above configuration, the apparatus further includes a demand controller capable of controlling a load amount of a part or all of the load, and the control device has a predetermined charging state of the power storage device in a state where the discharging operation is performed. It is desirable to reduce the load amount by operating the demand controller when the state falls below the threshold. According to this configuration, even when the remaining capacity of the power storage device becomes scarce, the level of the maximum peak power can be suppressed by operating the demand controller.

  According to the power storage system of the present invention, peak cutting can be reliably performed while suppressing the capacity of the power storage device. Therefore, the merits of introducing the power storage device can be ensured in the electric power consumer. For this reason, the incentive of power storage device introduction can be improved, which can contribute to the peak cut of power demand.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
<First Embodiment>
FIG. 1 is a block diagram schematically showing the configuration of a power consumer 1 equipped with a power storage system 4 according to the first embodiment of the present invention. The electric power consumer here assumes the high voltage electric power consumer like a factory. The power equipment 1 includes a power receiving equipment 2, loads 3A, 3B, 3C, and a power storage system 4.

  The power receiving facility 2 is a facility for the customer to receive power from a commercial power system developed by an electric power company, and includes a transformer, a switch, and the like. A power meter 21 for measuring the amount of received power is attached to the power receiving facility 2.

  The loads 3 </ b> A, 3 </ b> B, and 3 </ b> C are various electric devices that consume power, such as an electric motor, an electric furnace, an air conditioning facility, and an electric lamp. These loads 3 </ b> A, 3 </ b> B, and 3 </ b> C are normally operated by being supplied with electric power from the commercial power system via the power receiving facility 2.

  The power storage system 4 is interconnected to the power receiving facility 2 and the loads 3A, 3B, and 3C, and is charged with commercial power, while having a function of supplying power to the loads 3A, 3B, and 3C. The power storage system 4 includes a power storage device 5 and a control device 6. The power storage device 5 includes an AC / DC conversion device 51 and a secondary battery 52, and the control device 6 includes a charge / discharge control unit 61, a charge state detection unit 62, and a storage unit 63.

  The AC / DC converter 51 includes a rectifier and the like, converts AC commercial power of 50 Hz / 60 Hz into DC power, and converts DC power discharged from the secondary battery 52 into AC power. The secondary battery 52 is composed of a lithium secondary battery, a nickel-hydrogen storage battery, a nickel-cadmium storage battery, a lead storage battery, etc. that can be repeatedly charged and discharged, and is charged with commercial power while discharging the charging power. Power is supplied to the loads 3A, 3B, 3C.

  The charge / discharge control unit 61 of the control device 6 performs control to switch the operation mode of the AC / DC converter 51 and the secondary battery 52 to either the charge mode or the discharge mode. For example, the charge / discharge control unit 61 charges the secondary battery 52 during the nighttime power period (first time period), and discharges from the secondary battery 52 mainly during the daytime (second time period) power peak period. Control (first control) to perform switching is performed. By introducing the power storage device 5 and control as described above, part of the daytime power is covered by substantially inexpensive late-night power, and further, the power demand is cut to a peak, The customer can reduce the electricity charge. Hereinafter, this point will be described.

  FIG. 2 is a graph showing an example of the monthly power peak demand of a sample electric power consumer, and is a graph for explaining the situation of peak cut due to the introduction of the power storage device 5. Here, an example is shown in which peak demand is greatest in August.

Comparing the peak demand before and after the introduction of the power storage device 5, for example, the May peak demand P ₁₅ after the introduction is compared to the May peak demand P ₀₅ before the introduction, when the power storage device 5 is at the peak of power demand. are peak cut only borne by the d ₅ that bear some of the load. Similarly, the peak demand P ₁₈ for August after the introduction is peak-cut by a share d ₈ of the power storage device 5 with _respect to the peak demand P ₀₈ for August before the introduction. Thereby, the annual maximum peak demand of the electric power consumer is suppressed from P ₀₈ to P ₁₈ .

The current power charge system for general high-voltage consumers consists of the sum of a predetermined basic charge (contract charge) and a pay-as-you-go charge according to the amount of power used. The basic fee is determined by the maximum peak demand for the past year (January and the previous 11 months). In other words, if there is a prominent power usage record even in a small period of the year, the basic charge for the next year will be set accordingly. Therefore, it can be said that the magnitude of the annual maximum peak demand has a great influence on the electricity rate. In the example shown in FIG. 2, that in August following after the introduction of the electric storage device 5 is the peak cut by d _8, the maximum peak demand of the basic charge determination unit period at this point becomes P _18, the demand thereafter for one year and from the house of the demand curve is set the basic fee based on the P _18.

FIG. 3 is a graph for explaining the state of reduction in power charges due to the introduction of the power storage device 5. Comparing the power rate before and after the introduction of the electric storage device 5, for example, to May next power rate E ₀₅ before introduction, May following power rate E ₁₅ after introduction, daytime power by operation of the electric storage device 5 some have become cheaper by reductions c ₅ due to be covered by a substantially inexpensive midnight power. 2 and 3, for convenience of explanation, it is assumed that the power consumption and the maximum peak demand are the same values as in the same month of the previous year.

Also, in August following the maximum peak demand is peak cut only d ₈ on the border, the basic charge b1, which has been set in accordance with the August following peak demand P ₀₈ before the introduction, in August after the introduction Next It will be reduced to the basic charge b2, which is set according to the peak demand P _18. Thus, for example, to August next power rate E ₀₈ before introduction, August next power rate E ₁₈ after the introduction is substantially cheaper part of daytime power by operation of the electric storage device 5 for commodity charge along with the less expensive only reductions c ₈ due to be covered by a midnight power, it has become cheaper minute of difference Δb of the basic charge b1, b2. As described above, the introduction of the power storage device 5 enables the electric power consumer to reduce both the metered charge and the basic charge.

  In addition to the first control as described above, the charge / discharge control unit 61 requires a discharging operation by the power storage device 5 in a preset peak time zone in a time zone (second time zone) other than the nighttime power time zone. The second control is executed to cause the power storage device 5 to perform a charging operation when the power storage device 5 is not fully charged and is not fully charged (lower than a predetermined first threshold). Hereinafter, the second control will be described with reference to FIGS. 4 and 5.

  FIG. 4 is a graph showing a daily power demand pattern of a high-voltage power consumer (for example, a factory) in units of 30 minutes. In the example shown here, the power demand from the 8 o'clock to 17 o'clock range where the load facility operates is more prominent than in other time zones. In particular, since the power demand from 10 to 15 o'clock is large and the peak Pk appears in the time zone from 11:30 to 12:00, the time zone from 10:00 to 15 o'clock is the electric power consumer. It can be said that it is the peak time of demand. On the other hand, the power demand in the 12 o'clock range corresponding to the lunch break has a tendency to temporarily decrease.

  FIG. 5 is a graph showing an enlarged power demand pattern in the daytime time zone of FIG. When it is assumed that the contract power of the power consumer is 210 kW (Note that FIG. 5 shows the power demand (kWh) in units of 30 minutes. The contract power is the average demand power (kW) in units of 30 minutes. Since the power demand is 105 kWh for 30 minutes, the average demand power is 210 kW.) In the time zone A from 10:30 to 12:00 and the time zone B from 13:00 to 14:00 Demand for electricity exceeding contract power is occurring. Here, the total overload amount in time zone A is 10 kWh, and the total overload amount in time zone B is 5 kWh. Therefore, if it is going to cope with these excess loads only by the first control, it is necessary to prepare at least a power storage device 5 (secondary battery 52) having a capacity of 15 kWh that is the addition of time zone A and time zone B. There is.

  However, the capacity of the secondary battery 52 can be reduced by appropriately charging using the valley of power demand. In the example of FIG. 5, the power demand is lower than the contract power in the time zone C from 12:00 to 13:00 between the time zone A and the time zone B, and there is surplus power. Here, the total surplus power amount in time zone C is 17.5 kWh. If the control for charging the secondary battery 52 using the surplus power in the time zone C is performed, it is possible to cope with the overload in the time zone B even if the capacity of the secondary battery 52 is 10 kWh. Become.

  That is, even if the secondary battery 52 discharges the entire capacity corresponding to the overload in the time zone A, the remaining capacity is recovered by charging with the surplus power in the time zone C, thereby reducing the overload in the time zone B. I can cover it. The same applies when an overload in time zone B is not expected. As a result, it is possible for the power consumer to enjoy the merit that it is possible to prevent the excess of contract power, which will increase the basic charge, and to reduce the operation cost due to the suppression of the capacity of the secondary battery. be able to. In view of the above, the charge / discharge control unit 61 performs the second control.

  Here, the charge / discharge control unit 61 refers to the state of the secondary battery 52 so that the charging operation is performed in the time zone C in the example of FIG. That is, in the time zone before the time zone A, the secondary battery 52 is in a fully charged state by the charging operation by the first control at night, and charging itself is unnecessary. On the other hand, in time zone A, since the discharge to the load is performed, the charging operation cannot be performed. On the other hand, the time zone C is a state in which the discharge operation by the secondary battery 52 is not required, and the capacity is reduced because the secondary battery 52 is used. Accordingly, the charge / discharge control unit 61 causes the secondary battery 52 to perform a charging operation when such a state is detected in the peak time period.

  Returning to FIG. 1, the charging state detection unit 62 detects the charging state of the power storage device 5 (secondary battery 52). For example, a device that detects the state of charge by obtaining the battery voltage, battery temperature, integrated value of charge / discharge current, etc. of the secondary battery 52 can be used as the state of charge detection unit 62. The charge state detection result by the charge state detection unit 62 is sent to the charge / discharge control unit 61.

  The storage unit 63 includes a RAM (Random Access Memory) or the like, and includes time information related to a nighttime power time zone and a peak time zone of the power consumer, and a threshold value (first number) for performing a charging operation referred to in the second control. 1 threshold) value, contract power value, etc. are stored.

  Then, operation | movement of the electric power storage system 4 which concerns on embodiment of this invention comprised as mentioned above is demonstrated. FIG. 6 is a flowchart showing the overall operation of the power storage system 4. When the process is started, the charge / discharge control unit 61 refers to the data stored in the storage unit 63 and the current time is the night power time period (first time period) in which the power storage device 5 performs charging operation regularly. Whether or not it is a time zone (second time zone) in which the power storage device 5 performs a discharging operation is determined as necessary (step S1).

  In the first time zone, the charging / discharging control unit 61 causes the charging state detection unit 62 to detect the charging state of the power storage device 5 (secondary battery 52) (step S11), acquires the detection result, and performs charging. It is determined whether or not an operation is necessary (step S12). When the secondary battery 52 is fully charged or close to it and no charging operation is required (NO in step S12), the process returns to step S1 and is repeated. On the other hand, when the charging operation of the secondary battery 52 is necessary (YES in step S12), the charge / discharge control unit 61 sets the operation mode of the AC / DC converter 51 and the secondary battery 52 to the charging mode, and performs the charging operation. (Step S13). This charging operation is continued until the secondary battery 52 is fully charged or close to it.

  When it determines with it being the 2nd time slot | zone by step S1, the charging / discharging control part 61 performs control for 2nd time slot | zone (step S2). FIG. 7 is a flowchart showing the operation of the second time zone control. The charge / discharge control unit 61 acquires information on the amount of received power at the consumer from the wattmeter 21 at a predetermined sampling period (step S21), and determines whether the received power amount exceeds a set value. (Step S22). The set value here is, for example, the contract power shown in FIG.

  When the amount of received power exceeds the set value (YES in step S22), the charge / discharge control unit 61 sets the operation mode of the AC / DC converter 51 and the secondary battery 52 to the discharge mode and causes the discharge operation to be performed. (Step S23). In the example shown in FIG. 5, the discharge operation starts at 10:00. As a result, the power demand exceeding the contracted power can be covered by the power supply from the power storage device 5, and the power demand peak cut is made. Henceforth, it returns to step S21 and a process is repeated.

  On the other hand, when the amount of received power does not exceed the set value (NO in step S22), the charge / discharge control unit 61 detects the charge state of the secondary battery 52 via the charge state detection unit 62 (step S24). . If the secondary battery 52 is fully charged (YES in step S24), the process returns to step S1 in FIG. On the other hand, when the secondary battery 52 is not in a fully charged state (NO in step S24), the charge / discharge control unit 61 refers to the stored data in the storage unit 63 and the current time is the peak time zone ( For example, it is determined whether or not the time zone is 10 to 15 o'clock (step S25).

  When it is the peak time zone (YES in step S25), the charge / discharge control unit 61 sets the operation mode of the AC / DC converter 51 and the secondary battery 52 to the charge mode, and performs the charge operation (step S26). In the case of the example shown in FIG. 5, the charging operation is started at 12:00. Then, it returns to the said step S21 and a process is repeated. On the other hand, when it is not the peak time zone (NO in step S25), the charging operation is not immediately performed, and the process returns to step S1 in FIG. This is because the charging operation in the second time zone where the charging cost is high is avoided as much as possible, and the charging operation is performed in the first time zone.

Second Embodiment
In the power storage system 4 according to the first embodiment, unexpected power demand occurs, the remaining capacity of the power storage device 5 disappears during peak hours, and charging power cannot be supplied to the loads 3A, 3B, and 3C. obtain. In this case, the received power exceeds the contract power. Therefore, it is desirable to provide a system that can cope with unexpected power demand without increasing the capacity of the power storage device 5. Hereinafter, such a system will be exemplified as a second embodiment of the present invention.

  FIG. 8 is a block diagram briefly showing the configuration of the power facility 1A of the power consumer provided with the power storage system 4A according to the second embodiment of the present invention. The parts denoted by the same reference numerals as those of the power equipment 1 shown in FIG. 1 are the same parts as those of the first embodiment, and the description thereof is omitted or simplified here to avoid duplication.

  In this electric power facility 1A, a demand load 3D in which the load amount is forcibly controlled (demand control) is included in the load group, and the demand controller 7 that controls the load amount of the demand load 3D in the power storage system 4A; The point differs from the power equipment 1 shown in FIG. 1 in that a demand control unit 64 that controls the operation and stop of the demand controller 7 is included.

  Demand control is the target power by reducing the output of the load that is the target of demand control when the received power at the power consumer is likely to exceed the target power (in this case, the contracted power mentioned above). This is a control method for preventing the excess of the above. By providing a system that can execute such demand control, it is possible to prevent the received power from exceeding the contract power even when the remaining capacity of the power storage device 5 is depleted during the peak time period.

  The demand load 3D is a load that is relatively easily allowed to adjust its output, such as an air conditioner. The demand controller 7 grasps information on the amount of received power through the power meter 21 and reduces the power consumption (load amount) of the demand load 3D when the received power at the power receiving facility 2 is likely to exceed the contract power. Take control. The demand control unit 64 of the control device 6A activates the demand controller 7 when the remaining capacity of the power storage device 5 approaches zero (when the charged state falls below a predetermined second threshold).

  Then, operation | movement of 4 A of electric power storage systems which concern on 2nd Embodiment comprised as mentioned above is demonstrated. Since the overall operation of the power storage system 4A is the same as the flow shown in FIG. 6, the description thereof is omitted here. FIG. 9 is a flowchart showing an operation in the second time zone control of the power storage system 4A.

  The charge / discharge control unit 61 acquires information on the amount of received power at the consumer from the wattmeter 21 at a predetermined sampling period (step S31), and determines whether the amount of received power exceeds a set value. (Step S32). When the amount of received power exceeds the set value (YES in step S32), the charge / discharge control unit 61 checks the charge state of the secondary battery 52 via the charge state detection unit 62 (step S33).

  When the remaining capacity of the secondary battery 52 is equal to or greater than the predetermined value (second threshold), or when the discharge capacity remains in short (YES in step S33), the charge / discharge control unit 61 includes the AC / DC converter 51 and the secondary battery 52. The operation mode of the secondary battery 52 is set to the discharge mode, and the discharge operation is performed (step S34). On the other hand, when the discharge capacity of the secondary battery 52 does not remain (NO in step S33), the charge / discharge control unit 61 gives an instruction signal to the demand control unit 64. In response to this, the demand control unit 64 sets the demand controller 7 to the operating state and starts execution of demand control (step S4, step S41 in FIG. 10).

  When the amount of received power does not exceed the set value in step S32 (NO in step S32), the charge / discharge control unit 61 detects the charge state of the secondary battery 52 via the charge state detection unit 62 (step S35). ). If the secondary battery 52 is fully charged (YES in step S35), the process returns to step S1 in FIG.

  On the other hand, when the secondary battery 52 is not in a fully charged state (NO in step S35), the charge / discharge control unit 61 determines whether or not the current time is a peak time zone for the customer (step S36). . When it is the peak time zone (YES in step S36), the charge / discharge control unit 61 sets the operation mode of the AC / DC converter 51 and the secondary battery 52 to the charge mode, and performs the charge operation (step S37). On the other hand, when it is not the peak time zone (NO in step S36), the charging operation is not immediately performed, and the process returns to step S1 in FIG.

  FIG. 10 is a flowchart showing the demand control operation. When the demand controller 7 is activated (step S41), the demand control unit 64 acquires information on the amount of received power at the consumer from the wattmeter 21 at a predetermined sampling period (step S42). It is determined whether or not the set value (contract power) is exceeded (step S43).

  When the amount of received power exceeds the set value (YES in step S43), the demand control unit 64 checks the charged state of the secondary battery 52 via the charged state detection unit 62 (step S44). If the secondary battery 52 has no remaining capacity (NO in step S44), the demand control unit 64 maintains the operating state of the demand controller 7 (step S41).

  On the other hand, when the amount of received power does not exceed the set value (NO in step S43) or when the capacity of the secondary battery 52 exists, the demand control unit 64 causes the demand controller 7 to The operation state is shifted to the stop state (step S45). Thereafter, the process returns to step S31 of FIG.

  According to the power storage systems 4 and 4A according to the present embodiment described above, the peak cut can be reliably performed while the capacity of the power storage device 5 is suppressed. In particular, according to the power storage system 4A of the second embodiment, by using the demand control together, the received power exceeds the contract power even if the remaining capacity of the secondary battery 52 becomes low during the peak time period. Can be suppressed. Therefore, the merits of introducing the power storage device 5 can be ensured in the power consumer, the incentive for introducing the power storage device can be improved, and it can contribute to the peak cut of the power demand.

  Although the embodiment of the present invention has been described above, the present invention is not limited to this, and for example, the following embodiment can be taken.

[1] In the above-described embodiment, an example in which charging is performed when the power storage device 5 is not fully charged in the second control is shown (step S24 in FIG. 7 and step S35 in FIG. 9). Alternatively, the charging operation may be performed when the value is below a predetermined first threshold value that is less than the fully charged state. For example, in the case of a power consumer having a power demand curve as shown in FIGS. 4 and 5, since it is a curve that usually does not exceed the contract power after 14:00, the charging operation is performed immediately after time zone B. The first threshold (remaining discharge capacity) may be set to 5 kWh so that there is no such problem.

[2] The peak time zone set in the second time zone is not determined uniformly from 10:00 to 15:00, for example, but may be determined appropriately according to the circumstances of each power consumer. For example, in the case of a power customer who has a peak of power demand in the evening, the time zone is determined in the time zone, and in the case of a power customer having a power demand peak twice in the morning and evening, two time zones including this are defined as the peak time zone. Just do it. Alternatively, seasonal factors, days of the week, etc. may be added. For example, “Summer, Monday to Friday, 10:00 to 15:00”.

[3] As a charging system for the power storage device 5, another charging system may be added in addition to the commercial power system. For example, a solar cell or a cogeneration system may be connected to the power storage device 5 and used as a power source during the charging operation in the second time zone.

It is the block diagram which showed briefly the structure of the electric power installation of the electric power consumer provided with the electric power storage system which concerns on 1st Embodiment of this invention. It is a graph which shows an example of the monthly electric power peak demand of a sample electric power consumer. It is a graph for demonstrating the reduction state of the electric power charge by introduction of an electrical storage system. It is the graph which showed the daily power demand pattern in a certain high voltage electric power consumer (for example, factory) for every 30 minutes. It is a graph which expands and shows the electric power demand pattern in the daytime time slot | zone of FIG. It is a flowchart which shows the whole operation | movement of the electric power storage system which concerns on 1st Embodiment. It is a flowchart which shows the operation | movement of 2nd time slot | zone control. It is the block diagram which showed briefly the structure of the electric power equipment of the electric power consumer provided with the electric power storage system which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement in the 2nd time slot | zone control of the electric power storage system which concerns on 2nd Embodiment. It is a flowchart which shows the operation | movement of demand control.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A power equipment 2 Power receiving equipment 21 Wattmeter 3A, 3B, 3C Load 3D Demand load 4, 4A Power storage system 5 Power storage device 51 AC / DC converter 52 Secondary battery 6, 6A Control device 61 Charge / discharge control part 62 Charging state Detection unit 63 Storage unit 64 Demand control unit 7 Demand controller

Claims (4)

A power storage system applied to a consumer who receives power from a commercial power system and supplies power to a load,
A power storage device capable of discharging charged power and supplying power to the load while being charged by the commercial power;
A control device for controlling the charge / discharge operation of the power storage device,
The controller is
A predetermined first time zone is assigned as a time zone for causing the power storage device to perform a charging operation, and a second time zone different from the first time zone is assigned as a time zone for causing the power storage device to perform a discharging operation. A first control for performing a charging operation or a discharging operation for a required time in each time zone;
In a state where a discharging operation by the power storage device is not required in a peak time zone set in advance within the second time zone, and the charge state of the power storage device is lower than a predetermined first threshold, the power storage A power storage system capable of executing a second control for causing a device to perform a charging operation.   The power storage system according to claim 1, wherein the first time zone is a night power time zone.   The power storage system according to claim 1, wherein the second control is executed when the power storage device is not fully charged. A demand controller capable of controlling a part or all of the load;
The control device operates the demand controller to reduce the load amount when the state of charge of the power storage device falls below a predetermined second threshold in a state where the discharging operation is performed. The power storage system according to claim 1.

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