Charge / discharge control method and charge / discharge control system

Abstract

To provide a charge / discharge control method and a charge / discharge control system that, when there are multiple conditions for target power, appropriately controls charging and discharging in accordance with the conditions and in accordance with the state of charge / discharge control elements.SOLUTION: In a power system PS in which power is shared among a plurality of charge / discharge control elements, a parent device 11 generates first command information related to control of a first power supplied to the power system and second command information related to control of a second power, which is the total power supplied from power generation elements that generate power based on renewable energy, and transmits these to a plurality of child devices. A child device 21 receives the first command information and the second command information, calculates charge / discharge power based on the command information for each command information, acquires the charge rate of a storage battery provided in a charge / discharge control element 25, selects one of the plurality of charge / discharge powers as a target charge / discharge power on the basis of the charge rate, and controls the charge / discharge control element to charge / discharge at the target charge / discharge power.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a charge / discharge control method and a charge / discharge control system. [Background technology]

[0002] A technology has been proposed for a power system including a plurality of charge / discharge control elements and a centralized control device that manages the plurality of charge / discharge control elements (see Patent Document 1). According to this technology, the centralized control device calculates an index for controlling the individual output power of each of the plurality of charge / discharge control elements so that the power to be adjusted becomes a target power. Then, the charge / discharge control elements calculate individual target powers for each charge / discharge control element based on the index, and control the individual output powers to become the individual target powers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 150376 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the technology disclosed in Patent Document 1, the charge and discharge of each charge and discharge control element is controlled based on the calculated index and the priority of each charge and discharge control element. However, when there are multiple conditions for the target power, it is unclear from the charge and discharge control element which condition determines the increase or decrease of the index, which causes a problem that the charge and discharge of the charge and discharge control element cannot be appropriately controlled according to the state of the charge and discharge control element.

[0005] The present disclosure has been made in view of the above-mentioned problems, and aims to provide a charge / discharge control method and a charge / discharge control system that, when there are multiple conditions for a target power, can appropriately control the charge / discharge of a charge / discharge control element in accordance with the state of the charge / discharge control element while complying with the conditions. [Means for solving the problem]

[0006] The charge / discharge control method and charge / discharge control system according to the present disclosure relate to a power system in which power is shared among multiple charge / discharge control elements, and relate to a slave device installed in the charge / discharge control element and a master device connected to the slave device. The master device generates first command information related to control of a first power supplied to the power system, generates second command information related to control of a second power, which is the total power supplied from power generation elements that generate power based on renewable energy, and transmits the first command information and the second command information. The slave device receives the multiple command information, calculates charge / discharge power based on the command information for each command information, obtains the charging rate of a storage battery included in the charge / discharge control element, selects one of the multiple charge / discharge powers as a target charge / discharge power based on the charging rate, and controls the charge / discharge control element to charge / discharge at the target charge / discharge power. [Effects of the Invention]

[0007] According to the present disclosure, when there are multiple conditions for the target power, it is possible to appropriately control the charging and discharging of the charge and discharge control element in accordance with the conditions and in accordance with the state of the charge and discharge control element. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram showing a configuration of a charge / discharge control system according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a sequence diagram illustrating a processing example of the charge / discharge control system according to an embodiment of the present disclosure. [Figure 3] 10 is a flowchart showing a first example of a process for selecting a target charge / discharge power. [Figure 4]10 is a flowchart showing a second example of the process of selecting target charge / discharge power. [Figure 5] 10 is a flowchart showing a third example of a process for selecting a target charge / discharge power. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, several exemplary embodiments will be described with reference to the drawings. Note that common parts in the drawings are given the same reference numerals, and duplicated explanations will be omitted.

[0010] [Charge / discharge control system configuration] Fig. 1 is a block diagram showing the configuration of a charge / discharge control system according to an embodiment of the present disclosure. As shown in Fig. 1, the charge / discharge control system relates to a power system PS in which power is shared among a plurality of charge / discharge control elements 25. The charge / discharge control system includes a slave unit 21 and a master unit 11, which will be described later. The charge / discharge control system manages a plurality of charge / discharge control elements 25. Although three charge / discharge control elements 25 are shown in Fig. 1, the number of charge / discharge control elements 25 managed by the charge / discharge control system is not limited to three. The number of charge / discharge control elements 25 managed by the charge / discharge control system may be one or more.

[0011] For example, in order to exchange power among a plurality of charge / discharge control elements 25, the power system PS may receive power from a charge / discharge control element 25 under the control of the charge / discharge control system and transmit power to another charge / discharge control element 25 under the control of the charge / discharge control system. Also, the power system PS may transmit power received from a charge / discharge control element 25 under the control of the charge / discharge control system to a facility outside the control of the charge / discharge control system. Furthermore, the power system PS may transmit power received from a facility outside the control of the charge / discharge control system to a charge / discharge control element 25 under the control of the charge / discharge control system.

[0012] The charge / discharge control element 25 is an element capable of charging or discharging. In particular, the charge / discharge control element 25 controls charging or discharging based on a command from the slave device 21. For example, the charge / discharge control element 25 may include a storage battery. Furthermore, the charge / discharge control element 25 may be an electric vehicle.

[0013] The charge / discharge control element 25 may also be a load element that consumes power. For example, the load element may be a heating / cooling device, an elevator, an automatic door, a lighting device, etc. The load element is not limited to the examples given here.

[0014] The charge / discharge control element 25 may also be a power generation element that generates electric power. For example, the power generation element is a device that generates electric power based on various types of energy, such as solar, hydroelectric, wind, geothermal, and biomass. The power generation element may be a device that generates electric power based on renewable energy, or a device that generates electric power based on other energy sources. The power generation element is not limited to the examples given here.

[0015] The power meter 22 measures the power supplied from the power system PS to the charge / discharge control element 25, or the power supplied from the charge / discharge control element 25 to the power system PS. The power meter 22 is connected to the slave device 21, and transmits power information related to the measured power to the slave device 21. The power information may include information related to the power supplied from a power generation element that generates power based on renewable energy, among the charge / discharge control elements 25.

[0016] The slave device 21 is installed in the charge / discharge control element 25. The slave device 21 is connected to the master device 11 (described later) so as to be able to communicate with the master device 11. The slave device 21 includes a communication device and a controller. Here, the controller is a general-purpose computer including a CPU (Central Processing Unit), a memory, and an input / output unit. The master device 11 and the slave device 21 are connected via a wireless or wired communication circuit via the communication device.

[0017] The slave unit 21 transmits power information relating to the power measured by the power meter 22 to the master unit 11. The slave unit 21 may transmit the power information received from the power meter 22 as is, or may transmit the received power information averaged over a predetermined time interval as power information to the master unit 11. The method of obtaining the power information to be transmitted to the master unit 11 is not limited to the example given here.

[0018] The slave device 21 may also transmit request information indicating the requested power required by the charge / discharge control element 25 to the master device 11. Here, the slave device 21 may calculate the requested power based on the charge rate of the charge / discharge control element 25 (a value indicating the charge state of the storage battery, a power storage rate). The slave device 21 may also transmit the request information received from the charge / discharge control element 25 to the master device 11. The slave device 21 may transmit the request information received from the charge / discharge control element 25 as is, or may transmit a value obtained by averaging the received request information at predetermined time intervals to the master device 11 as request information. The method of obtaining the request information to be transmitted to the master device 11 is not limited to the example given here.

[0019] The master device 11 is connected to a plurality of slave devices so as to be able to communicate with them. The master device 11 includes a communication device and a controller. Here, the controller is a general-purpose computer including a CPU (Central Processing Unit), a memory, and an input / output unit. The master device 11 and the slave devices 21 are connected via a wireless or wired communication circuit via the communication device.

[0020] The master unit 11 receives the power information for each of the slave units 21. The master unit 11 may also receive information indicating the first power supplied to the power system PS from an external power source other than the charge / discharge control element 25. The master unit 11 may calculate the first power based on the power information received from the slave units 21.

[0021] Based on the first power, parent unit 11 generates first command information related to control of the first power. For example, parent unit 11 may generate the first command information so that the first power does not exceed the contracted purchased power (upper limit power) related to power system PS. In this case, the first command information may include a command to charge / discharge control element 25 to reduce the power consumed by charge / discharge control element 25.

[0022] Furthermore, when the first power is smaller than the contracted purchased power related to the power system PS and there is room to increase the first power, parent unit 11 may generate first command information to increase the first power. In this case, the first command information may include a command to charge / discharge control element 25 to increase the power consumed by charge / discharge control element 25.

[0023] Furthermore, the master device 11 may receive information indicating the second power, which is the total power supplied from the power generation elements that generate power based on renewable energy. The master device 11 may calculate the second power based on the power information received from the slave device 21.

[0024] Based on the second power, parent unit 11 generates second command information related to control of the second power. For example, parent unit 11 may generate the second command information so that the second power does not exceed the maximum amount of renewable energy (upper limit power) that can be generated in the power generation element of charge / discharge control element 25 under the management of power system PS. In this case, the second command information may include a command to charge / discharge control element 25 to reduce the power generated in charge / discharge control element 25.

[0025] Furthermore, when the second power is smaller than the maximum amount of renewable energy and there is room to increase the second power, parent device 11 may generate second command information to increase the second power. In this case, the second command information may include a command to charge / discharge control element 25 to increase the power generated by charge / discharge control element 25.

[0026] Note that the first process used by parent unit 11 to generate the first command information may be different from the second process used by parent unit 11 to generate the second command information. In other words, the first process and the second process may be processes based on different algorithms. For example, the first command information and the second command information may be generated based on the difference obtained by subtracting the power to be controlled from the upper limit power, or may be generated based on the power price calculated based on the power to be controlled, or different upper limit powers may be set between the first command information and the second command information.

[0027] Furthermore, parent unit 11 may retain a history of past first power. For example, parent unit 11 may retain information on the first power from the current time up to a first predetermined time in the past. Parent unit 11 may generate first command information based on the past history of the first power. Parent unit 11 may estimate the first power after a certain time has elapsed based on the past history of the first power, and generate first command information based on the estimated first power.

[0028] Similarly, the master unit 11 may retain a history of the past second power. For example, the master unit 11 may retain information on the second power from the current time up to a second predetermined time in the past. The master unit 11 may then generate second command information based on the past history of the second power. The master unit 11 may estimate the second power after a certain time has elapsed based on the past history of the second power, and generate second command information based on the estimated second power.

[0029] Here, the second predetermined time may be set shorter than the first predetermined time. Since fluctuations in the amount of power generated from renewable energy can be large, improving responsiveness is required. Therefore, the second predetermined time, which is the time span of the history used to generate the second command information related to the control of the second power, may be set shorter than the first predetermined time, which is the time span of the history used to generate the first command information related to the control of the first power.

[0030] Furthermore, parent device 11 may generate the first command information and the second command information so that the fluctuation range of the second power is smaller than the fluctuation range of the first power. For example, it is desirable to be able to charge in many charge / discharge control elements 25 using power based on renewable energy, while it is also desirable to reduce consumption of contracted power by controlling charging using priorities set for each charge / discharge control element 25. Therefore, the fluctuation range of the first power may be set to be larger than the fluctuation range of the second power.

[0031] In the above description, the first process used to generate the first command information and the second process used to generate the second command information are described as being executed by the same master unit 11, but this is not limiting. For example, the master unit 11 (first master unit) that executes the first process used to generate the first command information and the master unit 11 (second master unit) that executes the second process used to generate the second command information may be independent.

[0032] The master unit 11 transmits the generated first command information and second command information to one or more slave units 21.

[0033] The slave device 21 receives a plurality of pieces of command information including at least the first command information and the second command information. The slave device 21 may also receive a plurality of pieces of command information including third command information relating to control of a third power for the system group from a management server (not shown) that manages a system group including the power system PS.

[0034] Here, the management server is a server that manages the supply of power from the power system PS to other power systems in the system group, or the supply of power from other power systems to the power system PS. In other words, the management server controls the interchange of power between the power systems included in the system group.

[0035] For example, the management server may receive information indicating the third power, which is power supplied to the system group from an external power source other than the system group.

[0036] The management server may generate third command information so that the third power does not exceed the contracted purchased power (upper limit power) for the entire system group. In this case, the third command information may include a command to the power system to reduce the power consumed in the power system.

[0037] Furthermore, when the third power is smaller than the contracted purchased power for the entire system group and there is room to increase the third power, the management server may generate third command information to increase the third power. In this case, the third command information may include a command to the power system to increase the power consumed in the power system.

[0038] The management server may also receive information indicating the third power, which is the total power supplied from the power systems that generate power based on renewable energy.

[0039] The management server may generate third command information so that the third power does not exceed the maximum amount of renewable energy that can be generated in the power system under the management of the management server (upper limit power). In this case, the third command information may include a command to the power system to reduce the power generated in the power system.

[0040] Furthermore, when the third power is smaller than the maximum amount of renewable energy and there is room to increase the third power, the management server may generate third command information to increase the third power. In this case, the third command information may include a command to the power system to increase the power generated in the power system.

[0041] For each received command information, the slave device 21 calculates the charge / discharge power based on the command information. In addition, if the charge / discharge control element 25 includes a storage battery, the slave device 21 acquires the charging rate of the storage battery (a value representing the charging state of the storage battery, a power storage rate).

[0042] Furthermore, the slave device 21 selects one of the calculated charge / discharge powers as a target charge / discharge power based on the charging rate of the storage battery. The selection of the target charge / discharge power will be described later.

[0043] Then, the slave device 21 controls the charge / discharge control element 25 to charge / discharge at the selected target charge / discharge power. For example, when the charge / discharge power of the charge / discharge control element 25 is lower than the target charge / discharge power, feedback control may be performed to increase the charge / discharge power of the charge / discharge control element 25. Also, when the charge / discharge power of the charge / discharge control element 25 is higher than the target charge / discharge power, feedback control may be performed to decrease the charge / discharge power of the charge / discharge control element 25.

[0044] Alternatively, the slave device 21 may control the charge / discharge control element 25 by autonomous decentralized control or centralized control. The method by which the slave device 21 controls the charge / discharge control element 25 based on the target charge / discharge power is not limited to the examples given here.

[0045] [Selection of target charge / discharge power] Regarding the selection of the target charge / discharge power, for example, the slave device 21 may determine whether the charging rate of the storage battery is less than a predetermined threshold. If it is determined that the charging rate is less than the predetermined threshold, the slave device 21 may select the charging / discharging power based on the first command information as the target charge / discharge power. Alternatively, if it is determined that the charging rate is not less than the predetermined threshold, the slave device 21 may select the smaller value of the charging / discharging power based on the first command information and the charging / discharging power based on the second command information as the target charge / discharge power.

[0046] As a result, when the charging rate is low, the charge / discharge control element 25 can be charged within a range in which the first power does not exceed the contracted purchased power related to the power system PS. In other words, the charge / discharge control element 25 can be charged quickly while satisfying the conditions related to the first power.

[0047] Furthermore, when the charging rate is high, the charge / discharge control element 25 can be charged with the smaller value of the two charge / discharge powers (the charge / discharge power based on the first command information and the charge / discharge power based on the second command information). Therefore, the charge / discharge control element 25 can be charged within a range in which the first power does not exceed the contracted purchased power for the power system PS. Furthermore, the charge / discharge control element 25 can be charged within a range in which the second power does not exceed the maximum amount of renewable energy in the power system PS. In other words, the charge / discharge control element 25 can be charged while satisfying both the conditions related to the first power and the conditions related to the second power.

[0048] The predetermined threshold may be set based on the urgency level set in the charge / discharge control element 25. For example, if the charge / discharge control element 25 is an electric vehicle for emergency use, the urgency level is set high, and if the charge / discharge control element 25 is an electric vehicle for reserved use, the urgency level is set low. If the urgency level is high, the predetermined threshold may be set high, and if the urgency level is low, the predetermined threshold may be set low.

[0049] Furthermore, when the charge / discharge control element 25 is an electric vehicle, the predetermined threshold may be set according to the predicted stopping time of the electric vehicle. For example, if the stopping time is short, the predetermined threshold may be set to a large value, and if the stopping time is long, the predetermined threshold may be set to a small value. The slave device 21 may predict the stopping time based on the past driving record of the electric vehicle and the stopping record in the power system PS. The stopping time may be specified by the user of the electric vehicle.

[0050] The slave device 21 may calculate the maximum value of the charge / discharge power based on the second command information and the charge / discharge power based on the third command information. Then, when it is determined that the charging rate is not less than a predetermined threshold, the slave device 21 may select the smaller value of the charge / discharge power based on the first command information and the calculated maximum value as the target charge / discharge power.

[0051] As a result, when the charging rate is high, the charge / discharge control element 25 can be charged to the extent that the first power does not exceed the contracted purchased power for the power system PS. Furthermore, when there is renewable energy available in the power system PS, charging can be performed using the renewable energy of the power system PS. Furthermore, when there is a shortage of renewable energy available in the power system PS, power can be supplied from another power system other than the power system PS to charge the charge / discharge control element 25. As a result, surplus power in the other power system can be utilized.

[0052] Furthermore, the slave device 21 may acquire a time limit within which charging of the storage battery must be completed, and determine whether charging of the storage battery can be completed before the time limit elapses. For example, the slave device 21 may use a predicted stopping time of the electric vehicle as the time limit. The slave device 21 may acquire the time limit based on a scheduled time for the electric vehicle to depart after disconnecting from the power system PS. The scheduled time may be specified by the user of the electric vehicle, or may be set based on the past driving record of the electric vehicle and the past stopping record in the power system PS.

[0053] The slave device 21 may calculate the maximum value of the charge / discharge power based on the second command information and the charge / discharge power based on the third command information. Then, when it is determined that the charging rate is not less than the predetermined threshold and it is determined that charging of the storage battery cannot be completed before the time limit elapses, the slave device 21 may select the smaller value of the charge / discharge power based on the first command information and the calculated maximum value as the target charge / discharge power.

[0054] As a result, when the charging rate is high and charging of the storage battery cannot be completed before the time limit has elapsed, the charge / discharge control element 25 can be charged to the extent that the first power does not exceed the contracted purchased power for the power system PS. Furthermore, when there is renewable energy available in the power system PS, charging can be performed using the renewable energy of the power system PS. Furthermore, when there is a shortage of renewable energy available in the power system PS, power can be supplied from another power system other than the power system PS to charge the charge / discharge control element 25. As a result, surplus power in the other power system can be utilized.

[0055] Furthermore, the slave device 21 may calculate the minimum value of the charge / discharge power based on the second command information and the charge / discharge power based on the third command information. Then, when it is determined that the charging rate is not less than the predetermined threshold and that charging of the storage battery can be completed before the time limit elapses, the slave device 21 may select the smaller value of the charge / discharge power based on the first command information and the calculated minimum value as the target charge / discharge power.

[0056] As a result, when the charging rate is high and charging of the storage battery can be completed before the time limit elapses, the charge / discharge control element 25 can be charged to the extent that the first power does not exceed the contracted purchased power for the power system PS. Furthermore, when there is renewable energy available in the power system PS, power can be lent to other power systems other than the power system PS. Furthermore, even when there is a shortage of renewable energy available in the power system PS, the lent of power from other power systems other than the power system PS is suppressed. As a result, the cost associated with power wheeling can be reduced.

[0057] [Example of processing in a charge / discharge control system] 2 is a sequence diagram showing an example of processing of the charge / discharge control system according to the embodiment of the present disclosure. The processing shown in FIG. 2 may be repeatedly executed.

[0058] In step S101, master unit 11 generates first command information.

[0059] In step S103, master unit 11 generates second command information.

[0060] In step S105, parent device 11 transmits command information (first command information, second command information), and child device 21 receives the command information. Alternatively, child device 21 may receive third command information.

[0061] In step S107, the slave device 21 calculates the charge / discharge power based on each piece of command information received.

[0062] In step S109, the slave device 21 acquires the charging rate of the storage battery (a value indicating the charging state of the storage battery, a charging rate).

[0063] In step S111, the slave device 21 executes a process for selecting a target charge / discharge power.

[0064] In step S113, the slave device 21 controls the charge / discharge control element 25 to charge / discharge at the target charge / discharge power.

[0065] [Selection process of target charge / discharge power] 3 is a flowchart showing a first example of a process for selecting a target charge / discharge power. In step S201, the slave device 21 determines whether or not the charging rate is less than a predetermined threshold value.

[0066] If it is determined that the charging rate is less than the predetermined threshold (YES in step S201), the slave device 21 selects the charge / discharge power P1 based on the first command information as the target charge / discharge power Q in step S203.

[0067] On the other hand, if it is determined that the charging rate is not less than the predetermined threshold (NO in step S201), in step S211, the slave device 21 selects the smaller value of the charging / discharging power P1 based on the first command information and the charging / discharging power P2 based on the second command information as the target charging / discharging power Q.

[0068] Fig. 4 is a flowchart showing a second example of the process of selecting the target charge / discharge power. Unlike Fig. 3, if it is determined that the charging rate is not less than the predetermined threshold (NO in step S201), in step S221, the slave device 21 calculates the maximum value of the charge / discharge power P2 based on the second command information and the charge / discharge power P3 based on the third command information, and selects the smaller value of the charge / discharge power P1 based on the first command information and the calculated maximum value as the target charge / discharge power Q.

[0069] 5 is a flowchart showing a third example of the process of selecting the target charge / discharge power. Unlike in FIG. 3, if it is determined that the charging rate is not less than the predetermined threshold (NO in step S201), in step S231, the slave device 21 acquires the time limit within which charging must be completed.

[0070] In step S233, the slave device 21 determines whether or not charging of the storage battery can be completed before the time limit elapses.

[0071] If it is determined that charging can be completed before the time limit elapses (YES in step S233), in step S235, the slave unit 21 calculates the minimum value of the charge / discharge power P2 based on the second command information and the charge / discharge power P3 based on the third command information, and selects the smaller value of the charge / discharge power P1 based on the first command information and the calculated minimum value as the target charge / discharge power Q.

[0072] On the other hand, if it is determined that charging cannot be completed before the time limit has elapsed (NO in step S233), in step S237, the slave unit 21 calculates the maximum value of the charge / discharge power P2 based on the second command information and the charge / discharge power P3 based on the third command information, and selects the smaller value of the charge / discharge power P1 based on the first command information and the calculated maximum value as the target charge / discharge power Q.

[0073] [Effects of the embodiment] As described in detail above, the charge / discharge control method and charge / discharge control system according to the present disclosure relate to a power system in which power is shared among multiple charge / discharge control elements, and relate to a slave device installed in the charge / discharge control element and a master device connected to the slave device. The master device generates first command information related to control of a first power supplied to the power system, generates second command information related to control of a second power, which is the total power supplied from power generation elements that generate power based on renewable energy, and transmits the first command information and the second command information. The slave device receives the multiple command information, calculates charge / discharge power based on the command information for each command information, obtains the charging rate of a storage battery included in the charge / discharge control element, selects one of the multiple charge / discharge powers as a target charge / discharge power based on the charging rate, and controls the charge / discharge control element to charge / discharge at the target charge / discharge power.

[0074] This allows the charging and discharging of the charge / discharge control elements to be appropriately controlled in accordance with the conditions when there are multiple conditions for the target power, and in accordance with the conditions. In particular, the target charging and discharging power suitable for the charging and discharging of the charge / discharge control elements is set based on the charging rate, allowing the charging and discharging of the charge / discharge control elements to be appropriately controlled.

[0075] In the charge / discharge control method and charge / discharge control system according to the present disclosure, the parent device may generate the second command information by a second process different from the first process for generating the first command information. This allows appropriate control of the charge / discharge of the charge / discharge control elements even when multiple conditions for the target power are different.

[0076] Furthermore, in the charge / discharge control method and charge / discharge control system according to the present disclosure, the first parent unit that executes the first process and the second parent unit that executes the second process may be independent of each other. This allows the child unit to acquire command information from multiple parent units and set target charge / discharge power based on the command information.

[0077] In the charge / discharge control method and charge / discharge control system according to the present disclosure, the parent device may generate the first command information based on a history of the past first power, thereby enabling accurate control of the charge / discharge of the charge / discharge control element based on the history of the first command information.

[0078] Furthermore, in the charge / discharge control method and charge / discharge control system according to the present disclosure, the parent device may generate the second command information without relying on the history of past second power. This improves responsiveness in controlling the charge / discharge of the charge / discharge control elements based on the second command information. Even when the amount of power generated by renewable energy fluctuates significantly, the charge / discharge of the charge / discharge control elements can be appropriately controlled in response to the fluctuations.

[0079] Furthermore, in the charge / discharge control method and charge / discharge control system according to the present disclosure, the parent device may generate the first command information and the second command information so that the fluctuation range of the second power is smaller than the fluctuation range of the first power. This reduces the fluctuation range of the power based on renewable energy, making it possible to charge with many charge / discharge control elements. Furthermore, Since the fluctuation range of the contracted power increases according to the power demand of the charge / discharge control element, when the power demand is small, the consumption of the contracted power can be reduced.

[0080] Furthermore, in the charge / discharge control method and charge / discharge control system according to the present disclosure, the slave device may determine whether the charging rate is less than a predetermined threshold. This allows the target charging / discharging power to be switched between when the charging rate is less than the predetermined threshold and when it is not less than the predetermined threshold. As a result, appropriate charging / discharging control of the charge / discharge control elements can be performed based on the charging rate.

[0081] Furthermore, in the charge / discharge control method and charge / discharge control system according to the present disclosure, a predetermined threshold may be set based on the urgency level set for the charge / discharge control element. This allows the urgency level to be reflected in the charge / discharge control of the charge / discharge control element. For example, if the charge / discharge control element is an electric vehicle for emergency use, the urgency level may be set high, and if the charge / discharge control element is an electric vehicle for reserved use, the urgency level may be set low. Then, if the urgency level is high, the predetermined threshold may be set high, and if the urgency level is low, the predetermined threshold may be set low.

[0082] Furthermore, in the charge / discharge control method and charge / discharge control system according to the present disclosure, the slave device may select the charge / discharge power based on the first command information as the target charge / discharge power when it is determined that the charging rate is less than a predetermined threshold. Then, the slave device may select the smaller value of the charge / discharge power based on the first command information and the charge / discharge power based on the second command information as the target charge / discharge power when it is determined that the charging rate is not less than the predetermined threshold. This allows the charge / discharge control element to be charged within a range in which the first power does not exceed the contracted power purchase amount related to the power system when the charging rate is low. In other words, the charge / discharge control element can be charged quickly while satisfying the condition related to the first power.

[0083] Furthermore, when the charging rate is high, the charge / discharge control element can be charged with the smaller of the two charge / discharge powers (charge / discharge power based on the first command information and charge / discharge power based on the second command information). Therefore, the charge / discharge control element can be charged within a range in which the first power does not exceed the contracted purchased power for the power system. Furthermore, the charge / discharge control element can be charged within a range in which the second power does not exceed the maximum amount of renewable energy in the power system. In other words, the charge / discharge control element can be charged while satisfying both the conditions related to the first power and the conditions related to the second power.

[0084] In the charge / discharge control method and charge / discharge control system according to the present disclosure, the slave device may receive a plurality of pieces of command information, including third command information relating to control of a third power of the system group, from a management server that manages a system group including the power system. This allows the third command information to be reflected in the charge / discharge control of the charge / discharge control element.

[0085] Furthermore, in the charge / discharge control method and charge / discharge control system according to the present disclosure, when it is determined that the charging / discharging rate is not less than a predetermined threshold, the slave device may select, as the target charging / discharging power, the smaller of the maximum values ​​of the charging / discharging power based on the first command information, the charging / discharging power based on the second command information, and the charging / discharging power based on the third command information. This allows the charging / discharging control element to be charged when the charging / discharging rate is high, within a range in which the first power does not exceed the contracted power purchase amount for the power system. Furthermore, when renewable energy is available in the power system, the charging / discharging control element can be charged using the renewable energy of the power system. Furthermore, when there is a shortage of renewable energy available in the power system, the charging / discharging control element can be charged by borrowing power from another power system. As a result, surplus power in the other power system can be utilized.

[0086] In the charge / discharge control method and charge / discharge control system according to the present disclosure, the slave device may acquire a time limit for completing charging of the storage battery and determine whether charging of the storage battery can be completed within the time limit. This allows the target charge / discharge power to be switched depending on whether charging can be completed within the time limit or not. As a result, appropriate charge / discharge control of the charge / discharge control elements can be performed based on the time limit.

[0087] Furthermore, in the charge / discharge control method and charge / discharge control system according to the present disclosure, the charge / discharge control element in which the slave device is installed may be an electric vehicle. The slave device may acquire the time limit based on the scheduled time at which the electric vehicle will disconnect from the power system and depart. This allows the scheduled time at which the electric vehicle will disconnect from the power system and depart to be reflected in the charge / discharge control of the charge / discharge control element.

[0088] Furthermore, in the charge / discharge control method and charge / discharge control system according to the present disclosure, when it is determined that the charge rate is not less than a predetermined threshold and it is determined that charging of the storage battery cannot be completed within the time limit, the slave device may select the smaller of the maximum values ​​of the charge / discharge power based on the first command information, the charge / discharge power based on the second command information, and the charge / discharge power based on the third command information as the target charge / discharge power. This allows the charge / discharge control element to be charged within a range in which the first power does not exceed the contracted power purchase power for the power system when the charge rate is high and charging of the storage battery cannot be completed within the time limit. Furthermore, when renewable energy is available in the power system, the charge / discharge control element can be charged using the renewable energy of the power system. Furthermore, when there is a shortage of renewable energy available in the power system, the charge / discharge control element can be charged by borrowing power from another power system. As a result, surplus power in the other power system can be utilized.

[0089] Furthermore, in the charge / discharge control method and charge / discharge control system according to the present disclosure, when it is determined that the charging rate is not below a predetermined threshold and that charging of the storage battery can be completed within the time limit, the slave device may select the smaller of the minimum values ​​of the charging / discharging power based on the first command information, the charging / discharging power based on the second command information, and the charging / discharging power based on the third command information as the target charging / discharging power. This allows the charging / discharging control element to be charged within a range in which the first power does not exceed the contracted purchased power of the power system when the charging rate is high and charging of the storage battery can be completed within the time limit. Furthermore, when there is renewable energy available in the power system, power can be lent to another power system. Furthermore, even when there is a shortage of renewable energy available in the power system, power lent from another power system is suppressed. As a result, costs associated with power wheeling can be reduced.

[0090] Each function described in the above embodiments may be implemented by one or more processing circuits, including programmed processors, electrical circuits, and even devices such as application specific integrated circuits (ASICs), circuit components arranged to perform the described functions.

[0091] Although several embodiments have been described, the embodiments can be modified or varied based on the above disclosure. All components of the above embodiments and all features described in the claims may be individually extracted and combined, unless they contradict each other. [Explanation of symbols]

[0092] 11 Base unit 21 Handset 22 Power meter 25 Charge / discharge control element PS Power System

Claims

1. In an electric power system in which power is shared among a plurality of charge / discharge control elements, a charge / discharge control method is provided for a slave device installed in the charge / discharge control element and a master device connected to the slave device, the method comprising: The parent device is generating first command information related to control of a first power supplied to the power system from an external power source other than the charge / discharge control element; generating second command information related to control of a second power, which is a total power supplied from a power generation element that generates power based on renewable energy among the charge / discharge control elements; Transmitting the first command information and the second command information; The slave unit is receiving a plurality of pieces of command information including at least the first command information and the second command information; calculating, for each of the command information, charge / discharge power based on the command information; Acquire a charging rate of a storage battery included in the charge / discharge control element; selecting one of the plurality of charge / discharge powers as a target charge / discharge power based on the charging rate; Controlling the charge / discharge control element to charge / discharge at the target charge / discharge power. Charge and discharge control method.

2. The parent device is generating the second command information by a second process different from a first process for generating the first command information; The charge / discharge control method according to claim 1 .

3. the first parent device that executes the first process and the second parent device that executes the second process are independent of each other; The charge / discharge control method according to claim 2 .

4. The parent device is generating the first command information based on a history of the first power in the past; The charge / discharge control method according to claim 1 .

5. The parent device is generating the second command information without relying on a history of the second power in the past; The charge / discharge control method according to claim 1 .

6. The parent device is generating the first command information and the second command information so that a fluctuation range of the second power is smaller than a fluctuation range of the first power; The charge / discharge control method according to claim 1 .

7. The slave unit is determining whether the charging rate is less than a predetermined threshold; The charge / discharge control method according to claim 1 .

8. The predetermined threshold is set based on the urgency set in the charge / discharge control element. The charge / discharge control method according to claim 7.

9. The slave unit is When it is determined that the charging rate is less than the predetermined threshold, the charging / discharging power based on the first command information is selected as the target charging / discharging power; When it is determined that the charging rate is not less than the predetermined threshold, a smaller value of the charging / discharging power based on the first command information and the charging / discharging power based on the second command information is selected as the target charging / discharging power. The charge / discharge control method according to claim 7.

10. The slave unit is receiving a plurality of pieces of command information, including third command information relating to a third power control for the system group, from a management server that manages a system group including the power system; The charge / discharge control method according to any one of claims 1 to 6.

11. The slave unit is determining whether the charging rate is less than a predetermined threshold; The charge / discharge control method according to claim 10.

12. The slave unit is When it is determined that the charging rate is not less than the predetermined threshold value, the charge / discharge power based on the first command information; the maximum value of the charge / discharge power based on the second command information and the charge / discharge power based on the third command information and select the smaller value as the target charge / discharge power. The charge / discharge control method according to claim 11.

13. The slave unit is obtaining a time limit within which charging of the storage battery must be completed; determining whether charging of the storage battery can be completed before the time limit elapses; The charge / discharge control method according to claim 11.

14. the charge / discharge control element in which the slave device is installed is an electric vehicle, The slave unit is obtaining the time limit based on a scheduled time when the electric vehicle will depart after disconnecting from the power system; The charge / discharge control method according to claim 13.

15. The slave unit is When it is determined that the charging rate is not less than the predetermined threshold value and it is determined that charging of the storage battery cannot be completed before the time limit elapses, the charge / discharge power based on the first command information; the maximum value of the charge / discharge power based on the second command information and the charge / discharge power based on the third command information and select the smaller value as the target charge / discharge power. The charge / discharge control method according to claim 13.

16. The slave unit is When it is determined that the charging rate is not less than the predetermined threshold value and it is determined that charging of the storage battery can be completed before the time limit elapses, the charge / discharge power based on the first command information; the minimum value of the charge / discharge power based on the second command information and the charge / discharge power based on the third command information and select the smaller value as the target charge / discharge power. The charge / discharge control method according to claim 13.

17. In an electric power system in which power is shared among a plurality of charge / discharge control elements, the charge / discharge control system includes a slave unit installed in the charge / discharge control element and a master unit connected to the slave unit, The parent device is generating first command information related to control of a first power supplied to the power system from an external power source other than the charge / discharge control element; generating second command information related to control of a second power, which is a total power supplied from a power generation element that generates power based on renewable energy among the charge / discharge control elements; Transmitting the first command information and the second command information; The slave unit is receiving a plurality of pieces of command information including at least the first command information and the second command information; calculating, for each of the command information, charge / discharge power based on the command information; Acquire a charging rate of a storage battery included in the charge / discharge control element; selecting one of the plurality of charge / discharge powers as a target charge / discharge power based on the charging rate; Controlling the charge / discharge control element to charge / discharge at the target charge / discharge power. Charge and discharge control system.

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