JP6523184B2 - Storage device and management server of power supply system - Google Patents

Description

  The present invention relates to a storage device and a management server of a power supply system.

  DESCRIPTION OF RELATED ART The electrical storage apparatus which can store the electric power supplied from an electric power system in a storage battery, and can take out an electric power from a storage battery as needed is known. Power storage devices have been used in various fields in recent years, and their widespread use is progressing.

  One example of the power storage device is a battery charger built-in quick charger (charging station). Such a quick charger temporarily supplies power supplied from the power system to an internal storage battery, and then supplies power from the internal storage battery to an on-board storage battery such as an electric vehicle. If charging from the power system to the internal storage battery is performed with relatively small power, and charging from the internal storage battery to the in-vehicle storage battery is performed with large power, a large-scale power receiving facility for extracting large power from the power system. (Cubicle etc.) is unnecessary. That is, compared to the configuration in which the power extracted from the power system is directly supplied to the on-board storage battery, the power receiving facility can be made smaller and less expensive.

  Moreover, the power storage device installed in each home as a part of so-called HEMS is mentioned as another example of the power storage device. For example, by charging the power storage device in the nighttime where the power rate is low and consuming the power in the daytime, power consumption in the home can be equalized.

  In any case, there are a plurality of power storage devices as a whole, and power from the power system is supplied to the respective power storage devices. The number of power storage devices is, for example, the number of charging stations provided in the charging station, and is, for example, the number of consumers having HEMS in a specific area.

  By the way, when charging from the power system to the power storage device has been performed simultaneously in a plurality of power storage devices, the total value of power output from the power system (hereinafter, also referred to as "total supplied power") is temporarily It gets bigger. For this reason, it is necessary for the electric power company to take measures such as preparing a spare generator so as to cope with the large fluctuation of the total supplied electric power, resulting in a problem that the electric power price is increased. is there.

  Patent Document 1 below proposes a charging system configured to control charging operations of the respective power storage devices in an integrated manner by one centralized management device. In the charging system, the centralized management device individually sets the current value for charging each power storage device so that charging is started from the start time of the midnight time zone and charging is completed at the end time of the midnight time zone Do. According to the charging system having such a configuration, it is possible to suppress the fluctuation of the total supply power accompanying the charging, and to reduce the maximum value (peak) of the total supply power.

JP, 2011-155824, A

  The charging system described in Patent Document 1 is configured such that one centralized management device (supervisor) integrally performs detection of the storage amount in each storage device and setting of a charging current for each storage device. . In such a configuration, when the number of power storage devices changes, it is necessary to review the processing algorithm of the central control device accordingly. Since this becomes a factor causing deterioration of the extensibility, the charging system described in Patent Document 1 has poor scalability.

  The present invention has been made in view of such problems, and an object thereof is to control fluctuations in power supplied from a power system to a plurality of power storage devices without requiring comprehensive control by a centralized management device. An object of the present invention is to provide a storage device that can be suppressed and a management server of a power supply system.

  In order to solve the above-mentioned subject, an electricity storage device concerning the present invention is one electricity storage device among a plurality of electricity storage devices (100, 100A) to which electric power is supplied from electric power system (11), Storage unit (110) for storing the power supplied from the storage unit, a storage amount detection unit (121) for detecting the storage amount which is the amount of power stored in the storage unit, and the power price of the power supplied from the power system A price acquiring unit (122) to be acquired, and a control unit (120) that determines timing to start charging the storage unit and timing to end charging based on the power price and the storage amount. The power price is updated so as to be inversely proportional to the total supplied power, which is the total value of power supplied from the power system to each storage device, and the power price is updated after the power price is updated. The delay time which is the time until the price is acquired by the price acquisition unit is configured to fall within a predetermined setting range.

  In such a power storage device, the timing at which charging of the power storage unit is started is individually determined by the control unit of each power storage device, and charging is performed based on this. That is, the control unit of each power storage device performs control independently (autonomously and decentralized) from each other, instead of the external centralized management device performing overall control. Therefore, there is no need to reexamine the control algorithm when increasing or decreasing the number of power storage devices, and the entire system can be made highly scalable.

  According to the experiments conducted by the present inventors, the power price is updated so as to be inversely proportional to the total supplied power, and the delay time required for the transfer of the power price falls within a predetermined set range. If configured, it is known that the peak of the total supplied power can be suppressed even if each power storage device performs charging in an autonomous distributed manner.

  According to the present invention, there is also provided a management server for updating the total supply power and transmitting the total supply power to the respective power storage devices. Although such a management server is provided to manage the power supply system that supplies power from the power system to the plurality of power storage devices, it monitors the total supply power and calculates the power price calculated based thereon Is sent to each storage device. Therefore, it does not function as a centralized management device that comprehensively controls each power storage device.

  According to the present invention, the storage device capable of suppressing the fluctuation of the power supplied from the power system to the plurality of storage devices without requiring comprehensive control by the centralized management device, and management of the power supply system A server is provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the structure of the electrical storage apparatus which concerns on 1st Embodiment of this invention, and the structure of the electric power supply system which supplies electric power to several electrical storage apparatuses. It is a graph which shows the relationship between total power supply and electric power price. It is a schematic diagram for demonstrating the electric power charged / discharged to a storage battery, and the amount of electrical storage. It is a figure for demonstrating the peak of total power supply. It is a state transition diagram for demonstrating the conditions on which charge is performed. It is a graph which shows an example of the change of the amount of electrical storage. It is a flowchart which shows the procedure which determines various parameters. It is a figure for demonstrating the setting range of delay time. It is a figure which shows typically the structure of the electrical storage apparatus which concerns on 2nd Embodiment of this invention, and the structure of the electric power supply system which supplies electric power to a several electrical storage apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. In order to facilitate understanding of the description, the same constituent elements in the drawings are denoted by the same reference numerals as much as possible, and redundant description will be omitted.

  The power storage device according to the first embodiment of the present invention is configured as a charging stand 100 that charges an electric car or a plug-in hybrid car. As shown in FIG. 1, a plurality of charging stations 100 are installed in one charging station, and each charging station 100 is configured to be supplied with AC power from the power system 11. The power system 11, the management server 12, which will be described later, and the plurality of charging stations 100 collectively constitute a power supply system 10 for supplying power from the power system 11 to the plurality of charging stations 100. The power supply system 10 may include all the charging stations 100 installed at a plurality of charging stations in a specific area.

  The configuration of each of the plurality of charging stations 100 is identical to one another. The charging station 100 includes a storage battery 110, a storage amount detection unit 121, a price acquisition unit 122, and a control unit 120.

  Storage battery 110 is a storage battery for temporarily storing power (hereinafter also referred to as “system power”) supplied from power system 11 inside charging station 100. The grid power is converted into DC power by an input power converter (not shown) provided in the charging station 100 and stored in the storage battery 110.

  The power stored in storage battery 110 is boosted by an output power converter (not shown) provided in charging station 100 and supplied to electrically powered vehicle 200 through a charging cable (not shown). The electric power is charged to the on-board storage battery 210 provided in the electric vehicle 200 and then used as electric power for traveling the electric vehicle 200.

  Thus, the charging stand 100 according to the present embodiment charges the electrically powered vehicle 200 via the storage battery 110. That is, charging is performed by supplying the electric power from the electric power system 11 via the buffer of the storage battery 110 instead of directly supplying the electric vehicle 200 with the electric power. Under such a configuration, by performing control described later, it is possible to prevent temporary increase in system power output for charging.

The magnitude of the power shared from the power system 11 to the charging station 100 and the magnitude of the power supplied from the charging station 100 to the electric vehicle 200 change with the passage of time. In FIG. 1, assuming that the number of charging stations 100 is N, the magnitude of the power supplied from power system 11 to the first (the leftmost in FIG. 1) charging station 100 is represented by the charging power u ₁ (t). It is written as Similarly, the magnitude of the power supplied from the power system 11 to the second charging station 100 is denoted as charging power u ₂ (t), and the Nth (rightmost in FIG. 1) charging station 100 is used for the power system 11. The magnitude of the power supplied from is denoted as charging power u _N (t).

Further, the magnitude of the power supplied from the first charging station 100 to the electric vehicle 200 is denoted as discharge power v ₁ (t), and the magnitude of the power supplied from the second charging station 100 to the electric vehicle 200 Is denoted as discharge power v ₂ (t), and the magnitude of the power supplied from N-th charging stand 100 to electrically powered vehicle 200 is denoted as discharge power v _N (t).

  In addition, the storage battery 110 in the present embodiment has a plurality of banks inside. Further, by switching the connection state of these banks, storage battery 110 can be controlled to charge one bank and discharge it from another bank. That is, the storage battery 110 can perform discharge and charge simultaneously.

  The storage amount detection unit 121 is a sensor for detecting the amount of power stored in the storage battery 110, that is, the storage amount. The storage amount detected by the storage amount detection unit 121 is transmitted to the control unit 120.

  The price acquisition unit 122 is an interface for the charging station 100 to communicate with the outside. The price acquisition unit 122 acquires the power price of the power supplied from the power system 11 by communicating with the management server 12 described later. As described later, the power price is updated each time according to the magnitude of the power output from the power system 11, and is transmitted to the respective charging stations 100. The price acquisition unit 122 communicates with the management server 12 each time a predetermined cycle elapses, and acquires the latest power price.

  The control unit 120 is a part configured as a computer system provided with a CPU, a ROM, and the like. Control unit 120 controls the overall operation of charging stand 100 such as power supply (charging) from power system 11 to storage battery 110 and power supply (discharge) from storage battery 110 to electrically powered vehicle 200.

  Further, control unit 120 determines the timing for starting charging of storage battery 110 and the timing for ending charging. The determination is performed based on the power price acquired by the price acquisition unit 122 and the storage amount detected by the storage amount detection unit 121. The specific determination method will be described later.

  As shown in FIG. 1, power system 11 and each charging station 100 are connected by a power line 20, and system power is distributed to each charging station 100 through power line 20. An ammeter 13 is provided at a position closer to the power system 11 than any of the charging stations 100 among the power lines 20. The ammeter 13 is a sensor for measuring the magnitude of the current passing through the power line 20. The current value measured by the ammeter 13 is transmitted to the management server 12.

The management server 12 is a computer system operated and managed by a power company along with the power system 11. However, the management server 12 may be operated by a company other than the power company. The management server 12 always calculates the total value of power output from the power system 11 to all the charging stations 100 (hereinafter also referred to as “total supply power”) based on the current value transmitted from the ammeter 13. I know. The management server 12 updates the power price based on the latest total power supply, and transmits the updated power price to each charging station 100. As described above, since the power price changes with the passage of time, it will be described as power price p (t) below. The power price p (t) is calculated using the following equation (1).

  The denominator on the right side of the equation (1) corresponds to the total supply power which is the total value of the power supplied from the power system 11 to the respective charging stations 100. As shown in the equation (1), the power price p (t) is calculated so as to be inversely proportional to the total supplied power, so the relationship between the total supplied power and the power price is as shown in FIG. . When calculating the power price p (t), the right side of the equation (1) may be multiplied by a predetermined coefficient.

  In the following, in order to simplify the description, the case where the number of charging stations 100 (power storage devices) is two will be described. Below, the thing of the storage battery 110 with which the 1st charge stand 100 is equipped is also described with the 1st storage battery 111. FIG. Moreover, the thing of the storage battery 110 with which the 2nd charging stand 100 is equipped is also described with the 2nd storage battery 112. FIG.

  In FIG. 3, the flow of power supplied from the power system 11 to the first storage battery 111 and the second storage battery 112 is schematically shown in place of the flow of water. In FIG. 3, each storage battery is depicted as a container for storing water. The flow rate of water corresponds to the power to be charged and discharged, and the amount of water stored in the container corresponds to the storage amount.

Taking the first storage battery 111 as an example, if the charge power u ₁ (t) is larger than the discharge power v ₁ (t), the storage amount x ₁ (t) of the first storage battery 111 gradually increases It will be. Conversely, when the discharge power v ₁ (t) is larger than the charge power u ₁ (t), the storage amount x ₁ (t) will gradually decrease. The same applies to the storage amount x ₂ (t) of the second storage battery 112.

In the following, each of the charging power u ₁ (t), u ₂ (t), the discharging power v ₁ (t), v ₂ (t), and the storage amount x ₁ (t), x ₂ (t) is normalized. It is assumed that the value is Specifically, normalization is performed by dividing the power actually supplied from the power system 11 to the first storage battery 111 by the power value (fixed value) at the time of discharging from the first storage battery 111. It is assumed that the charge is again described as charging power u ₁ (t). The same applies to the charging power u ₂ (t).

The charging power u ₁ (t) can be either 0 or u ₁ . u ₁ is a value obtained by normalizing the charge performance of the first storage battery 111 by dividing it by the power value (fixed value) when discharged from the first storage battery 111. In addition, "charge performance" here is the magnitude | size of the electric power supplied to the storage battery 110, when charging.

Similarly, the charging power u ₂ (t) can be either 0 or u ₂ . u ₂ is the charging performance of the second battery 112 is a value obtained by normalizing by dividing the power values at the time of being discharged from the second battery 112 (a fixed value). In the following, u ₁ and u ₂ may be generally described as “u _i ” by using index i which can take 1 or 2.

In addition, the power when the first storage battery 111 charges the electrically powered vehicle 200 is normalized to be 1. That is, the discharge power v ₁ (t) is normalized to be a variable that can take a value of 0 or 1. However, it is assumed that the value of discharge power v ₁ (t) is always 1 because it is assumed that charging of electrically powered vehicle 200 is always performed below. The same applies to the discharge power v ₂ (t).

Furthermore, the storage amount normalized by dividing the actual storage amount of the first storage battery 111 by the maximum storage amount (that is, the capacity of the first storage battery 111), which is the maximum value of the storage amount, is stored again It is assumed that the quantity x ₁ (t). The same applies to the storage amount x ₂ (t).

In the following, charging power u ₁ (t) and charging power u ₂ (t) may be collectively expressed as “charging power u _i (t)” by using subscript i which can take 1 or 2 . Similarly, the storage amount x ₁ (t) and the storage amount x ₂ (t) may be collectively referred to as “the storage amount x _i (t)”. By using these, the relationship between the charging power u _i (t) and the storage amount x _i (t) is expressed by the following equation (2).

Further, the following equation (3) can be obtained by differentiating both sides of the equation (2) by time t.

As a method of controlling the charge and discharge of the first storage battery 111 and the like, for example, when the storage amount x _i (t) falls below a predetermined threshold, charging is started and the storage amount x _i (t) is 1 which is the maximum value. It is conceivable to stop charging when it is reached. In FIG. 4A, the charge amount x ₁ (t) and the charge amount x ₂ (charge charge / discharge) are performed without adjusting the delay time T and the like described later. An example of each change of t) is shown.

As shown in FIG. 4A, the storage amount x ₁ (t) and the storage amount x ₂ (t) will fluctuate independently within the range of 0 to 1. Therefore, depending on the timing at which each storage battery starts charging, a period may occur in which the storage amount x ₁ (t) and the storage amount x ₂ (t) simultaneously increase. That is, a period may occur in which the charging of the first storage battery 111 and the charging of the second storage battery 112 are performed simultaneously. In FIG. 4A, such periods are shown as periods TM1, TM3, TM5, and TM7.

  Similarly, a period may occur in which the charging of the first storage battery 111 and the charging of the second storage battery 112 are simultaneously stopped. That is, a period may occur in which only discharge is performed in any of the first storage battery 111 and the second storage battery 112. In FIG. 4A, such periods are shown as periods TM2, TM4, and TM6.

FIG. 4B shows the change of the total supply power. As shown in the figure, in a period TM1 or the like in which the charging of the first storage battery 111 and the charging of the second storage battery 112 are simultaneously performed, the total supplied electric power is u ₁ + u ₂ . On the other hand, in a period TM2 or the like in which only discharge is performed in any of the first storage battery 111 and the second storage battery 112, the total supplied power is zero. As described above, the total supplied power fluctuates greatly with the passage of time, and a peak occurs in the period TM1 and the like.

  When such a peak occurs in the total supply power, it is necessary for the electric power company to take measures such as preparing a spare generator to cope with the large fluctuation in the total supply power. As a result, there is a problem that the price of electricity increases.

  As a result of investigations conducted by the present inventors while carrying out simulations etc., if the setting method of the power price, the delay time of transmission, etc. are appropriately set, the occurrence of the peak of the total supplied power as shown in FIG. It has been found that it can be prevented and fluctuations in total supplied power can be suppressed. Below, the specific method for suppressing the peak of total power supply is demonstrated, using the example at the time of setting the number of charging stations 100 to two units continuously.

  First, the timing to start charging the storage battery 110 and the method of determining the timing to end charging will be described. As described above, these timings are determined by the control unit 120.

The state transition diagram shown in FIG. 5 shows the conditions of transition between the state ST1 in which the storage battery 110 is being charged and the state ST2 in which the storage battery 110 is not being charged. In state ST1, the value of charge power u _i (t) is set to u _i . In state ST2, the value of charge power u _i (t) is set to zero. The state transitions shown in FIG. 5 are performed independently of each other in both the first storage battery 111 and the second storage battery 112.

In state ST1, when the storage amount x _i (t) becomes 1, that is, when the storage battery 110 is fully charged, the state transitions to state ST2. In other words, the control unit 120 determines the charge end timing so that the charge ends when the storage amount x _i (t) becomes 1. Further, the control unit 120 terminates the charging at the above-mentioned timing by controlling the operation of the input-side power converter (not shown) provided in the charging stand 100.

In the state ST2, the electricity price p (t-T) is equal to or less than a predetermined lower limit price p _C, and when the storage amount x _i (t) is equal to or less than a predetermined lower limit accumulation amount x _C shifts to the state ST1. Here, “T” in the above condition elapses from the time when the power price p (t) is updated in the management server 12 to the time when the power price p (t) is obtained by the price obtaining unit 122 It is a delay time (hereinafter referred to as "delay time T"). Such a delay time T is caused by the signal transmission being delayed to some extent in the communication path from the management server 12 to the charging station 100. The power price acquired by the price acquisition unit 122 at time t is the power price updated by the management server 12 at time t-T. Therefore, as described above, the power price p (t−T) is indicated.

In the state ST2, when the storage amount x _i (t) decreases to the limit storage amount, the state is forcibly shifted to the state ST1 regardless of the value of the power price p (t−T). In the present embodiment, 0 is set as the value of the limit storage amount. The value of the limit storage amount may if configured as a value smaller than the lower limit accumulation amount x _C, it may be set to a value other than 0.

  The control unit 120 determines the charge start timing so as to start charging when the above conditions are satisfied. Further, charging is started at the above timing by controlling the operation of the input-side power converter (not shown) provided in the charging stand 100.

What is shown in FIG. 6 is an example of a change in the storage amount x _i (t) when the state ST1 and the state ST2 are switched under the above conditions. In the example shown in FIG. 6, the period until time t1 is in the state ST1, and the storage battery 110 is charged. At this time, the storage amount x _i (t) gradually increases and becomes 1 at time t1. Thereby, the state ST1 is switched to the state ST2.

Since only the discharge is performed after time t1, the storage amount x _i (t) gradually decreases. Thereafter, at time t2 when the storage amount x _i (t) becomes lower than the lower limit storage amount x _C and the power price p (t−T) becomes lower than the lower limit price p _C , the state ST2 switches to the state ST1 again ing.

After time t2, the storage battery 110 is charged similarly to the period up to time t1. The storage amount x _i (t) gradually increases and becomes 1 at time t3. Thereafter, the state ST1 is switched to the state ST2, and the storage amount x _i (t) gradually decreases.

In the example of FIG. 6, the electricity price p (t-T) is not become lower than the lower limit price p _C is after the time t3, the storage amount x _i (t) is finally reduced to 0 (time t4 ). As a result, at time t4, the state is switched from state ST2 to state ST1, and charging of storage battery 110 is resumed.

  A method of determining various parameters (such as delay time T) of the power supply system 10 will be described with reference to FIG. A series of procedures shown in FIG. 7 are sequentially performed in designing the power supply system 10.

In the first step S01, the charge performance of each of the first storage battery 111 and the second storage battery 112 is determined. The charge performance is the magnitude of the power supplied to the storage battery 110 when charging. Here, the charging performance of the first battery 111 is set to u _1, charging performance of the second battery 112 is set to u _2.

Each charge performance (u ₁ , u ₂ ) is a value greater than two. In other words, storage batteries whose normalized charge performance is greater than 2 are adopted as the first storage battery 111 and the second storage battery 112. In addition, although the 1st storage battery 111 and the 2nd storage battery 112 use the thing of the same type mutually, according to the individual difference of an apparatus, there exists a slight difference in the charging performance. Here, u ₂ is assumed to be larger than u ₁ . From the above, u ₂ u _1, and a charging performance of the second battery 112 is charged performance of the first battery 111 is set to satisfy the following equation (4).

In step S02 following step S01, the value of lower limit price p _C is set. The lower limit price p _C is set to satisfy the following equation (5).

In step S03 following step S02, the value of the lower limit storage amount x _C is set. The lower limit storage amount x _C is set to satisfy the following formula (6).

In equation (6), u ₁ is replaced with U ₁ by using U ₁ = 1 / (u ₁ −1). Similarly, u ₂ is replaced with U ₂ by using U ₂ = 1 / (u ₂ −1).

The lower limit storage amount x _C set in this way is normalized by dividing the lower limit storage amount set for the actual (that is, before normalization) storage amount by the maximum storage amount of the storage battery 110 It can be said. For this reason, the value of the lower limit storage amount x _{C is in} the range of 0 to 1.

In step S04 following step S03, the value of delay time T is set. The delay time T is set to satisfy the following equation (7).

  In the equation (7), the actual delay time is divided by the maximum storage amount of the storage battery 110, and the normalized value obtained by multiplying the power value (fixed value) at the time of discharging from the storage battery 110 is added again to the delay. It is written as time T. As a result of normalization, the value of delay time T is in the range of 0 to 1. In order to obtain the actual delay time T, it is necessary to convert the delay time T set to satisfy the equation (7) into the actual delay time by performing the reverse operation to the normalization.

FIG. 8 shows the range of the delay time T (however, normalized) which satisfies the equation (7). The horizontal axis in FIG. 8 is the lower limit storage amount x _C , and the vertical axis is the delay time T. The straight line L1 in FIG. 8 is a straight line expressed by the equation T = 1-x _C. As apparent from the comparison of the equation and the equation (7), the delay time T is set in the region below the straight line L1.

The straight line L2 in FIG. 8 is a straight line represented by the formula of T = 1/2 (1-x _C ). Moreover, the straight line L3 of FIG. 8 is a straight line represented by the formula of T = U ₁ (1-x _C ). As apparent from the comparison of these equations and equation (7), the delay time T is set in the region above the line L2 and the line L3.

In FIG. 8, the region below the straight line L1 is divided into a region AR1 above the straight line L2 (hatched portion) and a region AR2 below the straight line L2. Considering that the position of the straight line L3 fluctuates depending on the value of the charging performance (u ₁ and U ₁ ), the area AR1 is the maximum range in which the delay time T may satisfy the equation (7). Can.

  We repeated the simulation using various parameters. As a result, when the actual communication path is set such that the delay time T falls within the range shown by the equation (7), even if charging and discharging in each of the charging stations 100 are performed individually, as shown in FIG. It was found that the peak of the total supply power as shown in 4 (A) did not occur.

  As described above, in the charging station 100 (power storage device) according to the present embodiment, the timing to start charging the storage battery 110 and the timing to end charging are individually determined by the control unit 120 of the charging station 100. Charging is performed based on that.

  That is, the control unit 120 of each charging station 100 is configured to perform control independently (in an autonomously decentralized manner) rather than performing centralized control by an external centralized management device. While having such a configuration, the occurrence of a peak in the total supplied power is prevented. Therefore, it is not necessary to review the control algorithm or the like when increasing or decreasing the number of charging stations 100, and it is possible to make the system as a whole highly scalable.

  In the above description, although the case where the number of charging stations 100 (power storage devices) is two has been described, it is confirmed that the same effect can be obtained even when the number of charging stations 100 is three or more. There is.

  It is also conceivable that the delay time T becomes an area below the straight line L2 because the communication path from the management server 12 to each charging station 100 is short, for example. In such a case, a measure may be taken to extend the delay time T, for example, by interposing a relay having a relatively low processing speed.

  In addition, when the delay time T is in a region lower than the straight line L2, if the power price p (t) is calculated so as to be “proportional” to the total supplied power, the delay time is calculated. It has been confirmed by the present inventors that there is no peak in the total supplied power even if T remains short. Therefore, instead of taking measures to extend the delay time T, the method of calculating the power price p (t) may be changed as described above. The specific method at that time is as disclosed in Japanese Patent Application Laid-Open No. 2014-161151, and thus the specific description thereof is omitted here.

In the above description, an example in which the discharged power v ₁ (t) is smaller than the charged power u ₁ (t) has been described, but the discharged power can be set larger. . For example, the power (charging power) drawn from power system 11 to charging station 100 may be about 3 kW, and the power (discharging power) supplied from charging station 100 to electrically powered vehicle 200 may be about 50 kW.

  In the configuration as described above, since the power drawn from the power system 11 is relatively small, it is not necessary to install a high voltage power receiving facility such as a cubicle at the charging station. Nevertheless, the electric vehicle 200 can be charged with high power and completed in a short time.

In that case, the storage batteries 110 may be provided in multiple stages (that is, a plurality of storage batteries) in each of the power storage devices 100. For example, in a configuration in which storage battery 110 is provided in two stages, the power supplied from power system 11 to storage battery 110 in the previous stage is charging power u ₁ (t) or the like. If the supplied power is the discharged power v ₁ (t) or the like, it is possible to prevent the occurrence of a peak in the total supplied power in the same manner as described above.

Also in the above configuration, the charging power u ₁ (t) and the like are set to be larger than the discharging power v ₁ (t) and the like. Further, the electric power supplied from storage battery 110 at the rear stage to electric powered vehicle 200 is set to be larger than any of charge electric power u ₁ (t) and the like, and discharge electric power v ₁ (t) and the like.

  A second embodiment of the present invention will be described with reference to FIG. The power storage device according to the second embodiment is configured as a power storage device 100A installed in a general home 300 as a part of a so-called HEMS. In the example of FIG. 9, there are N households 300 provided with HEMS in a specific area, and each household 300 is provided with the power storage device 100A.

  Power supply from power system 11 to each home 300 is performed via power storage device 100A. The power system 11, the management server 12, and the plurality of power storage devices 100A collectively constitute a power supply system 10A that supplies power from the power system 11 to the plurality of power storage devices 100A.

  Each power storage device 100A stores the power supplied from power system 11 in storage battery 110A, and supplies the power discharged from storage battery 110A to home 300 as necessary. The home 300 supplies the power to the power load 310 for consumption. The power load 310 is, for example, a power consumption device such as an air conditioner.

  In each home 300, for example, the power storage device 100A is charged in the nighttime when the power rate is low, and the power consumption in the home 300 can be equalized by consuming the power in the daytime.

  Although “A” is attached to the reference numeral indicating the storage device 100A and each part thereof, the configuration of the storage device 100A and the contents of processing performed by the control unit 120 have been described in the first embodiment. It is similar to the one.

  Also in the present embodiment, charge and discharge of each storage battery 110A is performed by the respective power storage devices 100A performing control independently (in an autonomous distributed manner), instead of one centralized management device performing overall control. To be done. In such an embodiment, it is possible to prevent the generation of a peak in the total supply power, so that the power company does not need to prepare an extra spare generator. As a result, it can be expected that the power price paid by each home 300 is further suppressed.

  As a method for leveling the power consumed by each home 300, there is also known a so-called dynamic pricing method in which a centralized management device adjusts the power demand by appropriately determining the power price. However, in such an aspect, it is necessary for the centralized management device to keep on performing complicated calculations for setting an appropriate power price for power leveling.

  On the other hand, the management server 12 of the present embodiment measures only the total supply power, converts it into a power price by a simple calculation (see FIG. 2), and transmits it. As described above, in the present embodiment, it is possible to suppress the peak of the total supply power while having an extremely simple configuration without providing a centralized management device for complicated calculation and general control.

  The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. That is, those to which those skilled in the art appropriately modify the design of these specific examples are also included in the scope of the present invention as long as they have the features of the present invention. For example, each element included in each specific example described above and its arrangement, material, conditions, shape, size, and the like are not limited to those illustrated, and can be appropriately changed. Moreover, each element with which each embodiment mentioned above is equipped can be combined as much as technically possible, and what combined these is also included in the scope of the present invention as long as the feature of the present invention is included.

10, 10A: power supply system 11: power system 12: management server 100: charging station 100A: power storage device 110, 110A: storage battery 120: control unit 121: storage amount detection unit 122: price acquisition unit

Claims (5)

One of the plurality of storage devices (100, 100A) to which power is supplied from the power system (11),
A storage unit (110) for storing power supplied from the power system;
A storage amount detection unit (121) that detects a storage amount that is an amount of power stored in the storage unit;
A price acquisition unit (122) for acquiring the power price of the power supplied from the power system;
The control unit (120) determines timing to start charging the storage unit and timing to end charging based on the power price and the storage amount.
The power price is updated so as to be inversely proportional to a total supplied power which is a total value of power supplied from the power system to each of the power storage devices,
A power storage device configured such that a delay time, which is a time from when the power price is updated to when the power price is acquired by the price acquisition unit, falls within a predetermined setting range. The control unit
The power storage device according to claim 1, wherein charging of the power storage unit is started at a timing when the power price falls below a predetermined lower limit price and the storage amount falls below a predetermined lower limit storage amount. The control unit
When the said amount of electrical storage falls to the limit electrical storage amount set as a value smaller than the said minimum electrical storage amount, charge to the said electrical storage part is started based on the value of the said electric power price, It is characterized by the above-mentioned. Power storage device. What is normalized by dividing the lower limit storage amount by the maximum storage amount, which is the maximum value of the storage amount, is x _C ,
Let T be a normalized value obtained by dividing the maximum storage amount by the delay time and multiplying the value by the power discharged from the storage unit.
The setting range is at least 1/2 (1-x _C ) <T <1-x _C
The power storage device according to claim 3, which is a range in which the equation of is established. A management server (12) of a power supply system for supplying power from a power system to a plurality of power storage devices,
The power storage device according to any one of claims 1 to 4 is used as the power storage device.
Updating the power price to be inversely proportional to the total supply power;
A management server that transmits the updated power price to each of the power storage devices.

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