Power management system and power management method

Abstract

To reduce a user burden in a case where selling / buying of power occurs in a power adjustment resource.SOLUTION: A power management system 500 comprises: a HEMS controller 15 which controls a corresponding HEMS 10 in a plurality of power adjustment resources; and an energy management server 2 which sets power management control due to the HEMS controller 15. The power management control includes: plan control in which the HEMS controller 15 is commanded to control the HEMS 10 on the basis of a predetermined power demand / supply plan; and edge control in which the HEMS controller 15 is commanded to control the HEMS 10 based on actual situations of surplus power and demand / supply power of the HEMS 10. The energy management server 2 commands the edge control to the HEMS controller 15 during a period in which occurrence of at least one of selling of surplus power and buying of demand / supply power is predicted in the HEMS 10 during execution of the plan control.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to power management systems and methods, and more particularly to systems and methods for managing power demand and supply in a power grid that includes multiple power regulating resources. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2016-187254 (Patent Document 1) discloses a method for controlling a storage battery with little power loss of electricity generated using renewable energy, and a method for controlling a water heater that can be controlled so that the power does not fall below the minimum required value. Patent Document 1 also describes the calculation of a prediction error of prediction data using operation plan data of the storage battery and actual operation performance data. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-187254 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a power grid including a plurality of power adjustment resources (for example, a home energy management system described later), not only the actual power supply and demand of a certain resource changes according to a power supply and demand plan, but also the resource may buy and sell power, i.e., may sell surplus power and / or buy demand power (power shortage). When power is bought and sold in this way, it is desirable to reduce the burden on the user of the resource.

[0005] The present disclosure has been made to solve the above problems, and one of the objectives of the present disclosure is to reduce the burden on users when power is bought and sold in a power adjustment resource. [Means for solving the problem]

[0006] A power management system according to an aspect of the present disclosure manages power supply and demand in a power network including a plurality of power adjustment resources. The power management system includes a controller that controls a corresponding resource that is a corresponding power adjustment resource among the plurality of power adjustment resources, and a server that sets power management control by the controller for the corresponding resource. The power management control includes a first control that instructs the controller to control the corresponding resource based on a power supply and demand plan that has been formulated in advance, and a second control that instructs the controller to control the corresponding resource based on actual conditions of surplus power and demand power in the corresponding resource. During execution of the first control, the server instructs the controller to perform the second control during a period in which at least one of selling surplus power and buying demand power is predicted to occur in the corresponding resource.

[0007] A power management method according to another aspect of the present disclosure manages power supply and demand in a power network including a plurality of power adjustment resources. The power management method includes a step of setting, by a server, a power management control of a corresponding resource that is a corresponding power adjustment resource among the plurality of power adjustment resources, to a controller. The power management control includes a first control instructing the controller from the server to control the corresponding resource based on a power supply and demand plan formulated in advance, and a second control instructing the controller from the server to control the corresponding resource based on actual conditions of surplus power and demand power in the corresponding resource. The setting step includes a step of predicting whether at least one of selling surplus power and buying demand power will occur in the corresponding resource during execution of the first control, and a step of switching the power management control from the first control to the second control during a period in which at least one of selling surplus power and buying demand power is predicted to occur. Effect of the Invention

[0008] According to the present disclosure, it is possible to reduce the burden on users when power is bought and sold in power adjustment resources. [Brief description of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating an example of an overall configuration of a power management system according to an embodiment of the present disclosure. [Diagram 2] 4 is a time chart for explaining an overview of power management control in the present embodiment. [Diagram 3] 10 is a flowchart showing an example of a processing procedure of power management control in the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference characters and their description will not be repeated.

[0011] [Embodiment Mode] <System configuration> 1 is a diagram showing an example of an overall configuration of a power management system according to an embodiment of the present disclosure. The power management system 500 includes a CEMS 1 and an energy management server 2.

[0012] CEMS1 stands for Community Energy Management System or City Energy Management System. CEMS1 includes, for example, multiple Home Energy Management Systems (HEMS) 10. In CEMS1, a microgrid MG is constructed by multiple HEMS 10. The microgrid MG is connected to the power grid 9 so as to be able to exchange power with the power grid 9. The power grid 9 is a power network constructed by power plants and power transmission and distribution facilities.

[0013] The microgrid MG is an example of the "power grid" according to the present disclosure. The CEM1 may include a Factory Energy Management System (FEMS) or a Building Energy Management System (BEMS) instead of or in addition to the HEMS 10. The CEM1 may include only one of the energy management systems.

[0014] Each of the multiple HEMS 10 manages the electricity used in the home (electricity consumption, demand, and supply). Each HEMS 10 includes, for example, a water heater 11, an electric vehicle 12, a storage battery 13, a PV (photovoltaic) power generation facility 14, and a HEMS controller 15.

[0015] The water heater 11 is, for example, a water heater of a cogeneration system (it may be a water heater that uses heat generated during private power generation, or it may be a heat pump water heater). The water heater 11 boils the optimal amount of hot water according to the hot water usage of each household at night using inexpensive midnight electricity, and stores the boiled water in a hot water storage tank for use the next day (so-called boiling).

[0016] The electric vehicle 12 is a vehicle including a battery (not shown), and specifically, is a plug-in hybrid electric vehicle (PHEV), a battery electric vehicle (BEV), or the like. The electric vehicle 12 is configured to receive power from the microgrid MG by connecting a charging cable extending from a charging facility (not shown) to an inlet (not shown) of the electric vehicle 12 (external charging). The electric vehicle 12 may be configured to be able to discharge power to the microgrid MG by connecting a charging cable to an outlet (not shown) of the electric vehicle 12 (external discharging). In this way, the electric vehicle 12 also functions as a mobile power storage device.

[0017] The storage battery 13 is a stationary power storage device that stores power generated during the day by the PV power generation facility 14. The storage battery 13 is a secondary battery such as a lithium ion battery or a nickel-metal hydride battery, and may be manufactured using, for example, a driving battery that was previously installed in a vehicle.

[0018] The PV power generation equipment 14 receives sunlight during the day to generate electricity, and charges the storage battery 13 with the generated electricity or outputs it to the microgrid MG. Instead of or in addition to the PV power generation equipment 14, the HEMS 1 may include other naturally variable power sources (power generation equipment whose power output fluctuates depending on weather conditions) such as wind power generation equipment.

[0019] The above devices are merely examples, and the HEMS 10 may further include devices (electrical devices or V2H devices such as air conditioners, fuel cells, lighting devices, generators, and heat storage tanks) other than those described above (not shown). Each device in the HEMS 10 corresponds to a "power regulation resource" according to the present disclosure.

[0020] The HEMS controller 15 is configured to be able to communicate with each device in the HEMS 1. The HEMS controller 15 acquires information about each device and controls the operation of each device.

[0021] The HEMS controller 15 is configured to communicate bidirectionally with the energy management server 2. The HEMS controller 15 transmits values ​​(power values, status values, etc.) indicating the operating status of each device acquired from the device to the energy management server 2. The HEMS controller 15 also controls each device according to a control command from the energy management server 2.

[0022] The energy management server 2 is a higher-level computer (cloud server) that comprehensively manages the multiple HEMS controllers 15. The energy management server 2 includes a processor 201, a memory 202, and a communication interface 203. The processor 201 executes various processes by reading out programs and various data (maps, relational expressions, parameters, etc.) stored in the memory 202 and expanding them in the memory 202. The communication interface 203 is configured to communicate with each of the multiple HEMS controllers 15. The energy management server 2 executes "power management control" for each of the multiple HEMs 10, which manages charging, power consumption, and / or discharge within the HEMS 10. This control will be described later.

[0023] Each of the HEMS controllers 15 corresponds to a "controller" according to the present disclosure. The energy management server 2 corresponds to a "server" according to the present disclosure.

[0024] <Power management control> The energy management server 2 formulates an electric power supply and demand plan for each HEMS 10, which is a consumer in the CEM 1, based on the electric power rate unit price and receiving end power forecast of that HEMS 10 so as to minimize the electric power charge of that HEMS 10. Then, the energy management server 2 executes "planned control" according to the electric power supply and demand plan for each HEMS 10. In planned control, the energy management server 2 holds the control right of each device in the HEMS 10, and the energy management server 2 controls each device in the HEMS 10 in a cooperative manner. This makes it possible to maximize self-consumption in the HEMS 10 and suppress (minimize) the electric power charge.

[0025] However, the actual power supply and demand of the HEMS 10 does not necessarily follow the power supply and demand plan to suppress the electricity bill. The behavior of a consumer on one day may differ from the behavior of a consumer on another day (normal behavior pattern). Alternatively, the weather may change from moment to moment, or the weather may cause a change different from the change predicted based on past data. As a result, the power generation amount of a naturally variable power source such as the PV power generation facility 14 may change differently from the prediction. In addition, it is difficult to formulate a precise power supply and demand plan with a short time granularity (for example, in units of one minute). Therefore, there is a possibility that the buying and selling of power occurs in the HEMS 10, that is, there is a possibility that there is a period in which the surplus power of the HEMS 10 is sold, or a period in which the demand power (power shortage) of the HEMS 10 is purchased. When such a period occurs, the amount of power purchased and / or sold increases compared to the case in which the actual power supply and demand is always in line with the power supply and demand plan, and the electricity bill may increase accordingly.

[0026] Therefore, in this embodiment, during the execution of planned control, in the period when buying and selling of electricity is predicted to occur, in this example, when the PV power generation equipment 14 is predicted to sell surplus electricity or when electricity is predicted to be purchased due to an increase in electricity demand of the equipment (air conditioners, lighting equipment) within the HEMS 10, the energy management server 2 switches the power management control from "planned control" to "edge control".

[0027] In edge control, the control rights of each device in the HEMS 10 are transferred (assigned) from the energy management server 2 to the HEMS controller 15. The HEMS controller 15 monitors the power at the receiving end of the HEMS 10. The HEMS controller 15 then closely controls the charging and discharging of each device in the HEMS 10 (the water heater 11, the electric vehicle 12, and the storage battery 13 in this example) in accordance with changes in the amount of power bought and sold at the receiving end of the HEMS 10. This reduces the amount of power bought and sold at the receiving end of the HEMS 10, maximizing self-consumption. As a result, it becomes possible to reduce the electricity charges for the HEMS 10.

[0028] The switching between the planned control and the edge control will be described in more detail below. Note that the planned control corresponds to the "first control" in this disclosure, and the edge control corresponds to the "second control" in this disclosure.

[0029] <Switching between planned control and edge control> FIG. 2 is a time chart for explaining an overview of power management control in this embodiment. The horizontal axis represents elapsed time. More specifically, the horizontal axis represents elapsed time in a specific target period (in this example, the period from midnight to midnight the following day). The vertical axis represents power (generated power or demanded power). From the top, FIG. 2 shows, for a target HEMS 10, a power forecast for the following day in the HEMS 10, an operation plan for the water heater 11, an operation plan for the electric vehicle 12, an operation plan for the storage battery 13, and a type of power management control.

[0030] The energy management server 2 predicts the receiving end power of the target HEMS 10 during a target period at a predetermined timing. In this example, it is assumed that the prediction is performed at midnight, and as a result, it is predicted that surplus power will occur from 8:00 to 15:00, and that demand power (i.e., power shortage) will occur from 17:00 to 22:00. It is also assumed that inexpensive midnight power is available from midnight until 7:00.

[0031] It is predicted that neither surplus power nor demand power will occur during the period from midnight to 8:00. Therefore, the energy management server 2 executes planned control. Therefore, the energy management server 2 has the right to control each device in the HEMS 10 during this period.

[0032] During the period up to 7:00, the energy management server 2 executes the following control using inexpensive midnight power. First, the energy management server 2 determines the time when the water heater 11 heats up. In this example, in order to heat up an optimal amount of hot water by 17:00 when the occurrence of power demand is predicted, the energy management server 2 controls the water heater 11 to heat at least a part of the optimal amount of hot water using midnight power. Second, the energy management server 2 charges the electric vehicle 12 so that the SOC of the electric vehicle 12 reaches a target value at the scheduled departure time of the electric vehicle 12. In this example, the energy management server 2 charges the electric vehicle 12 to at least an intermediate SOC (e.g., SOC=60%) using midnight power so that the SOC reaches a target SOC (e.g., SOC=80%) at 12:00, which is the scheduled departure time. Third, the energy management server 2 charges the storage battery 13 using midnight power.

[0033] It is predicted that surplus power will be generated during the period from 8:00 to 15:00. Accordingly, there is a high possibility that power will be sold at the power receiving end of the HEMS 10. Therefore, the energy management server 2 switches the power management control from planned control to edge control. Therefore, during this period, the control rights of each device in the HEMS 10 are transferred from the energy management server 2 to the HEMS controller 15.

[0034] The HEMS controller 15 controls the actual power consumption of the HEMS 10 (the total value of the charging power or power consumption of each device) so that it is within the range of surplus power and is as close as possible to the surplus power in order to reduce the amount of power sold at the power receiving end of the HEMS 10. In this example, the HEMS controller 15 first charges the electric vehicle 12 with power equivalent to the remaining SOC (e.g., the remaining 20% ​​between 60% and 80%) from the SOC at which charging was stopped midway to the final SOC so that the SOC of the electric vehicle 12 reaches the target SOC by the scheduled departure time of the electric vehicle 12. The HEMS controller 15 also controls the water heater 11 to boil the remaining hot water (the difference between the optimal amount of hot water and the part of the hot water boiled using the midnight power) using the night power in order to boil the optimal amount of hot water by 5 p.m. when power demand occurs. Furthermore, the HEMS controller 15 charges the storage battery 13 with the surplus power that cannot be charged or consumed by the water heater 11 and the electric vehicle 12 (the surplus power minus the power consumed by the water heater 11 and the charging power of the electric vehicle 12).

[0035] It is predicted that neither surplus power nor demand power will occur during the period from 15:00 to 17:00. Therefore, the energy management server 2 returns the power management control from edge control to planned control. Therefore, the energy management server 2 takes back the control right of each device in the HEMS 10 from the HEMS controller 15.

[0036] It is predicted that power demand will occur in the period from 17:00 to 22:00. Accordingly, there is a high possibility that power will be purchased at the power receiving end of the HEMS 10. Therefore, the energy management server 2 switches the power management control from planned control to edge control again. Therefore, during this period, the control rights of each device in the HEMS 10 are transferred again from the energy management server 2 to the HEMS controller 15.

[0037] The HEMS controller 15 controls the actual power supply (total value of power discharged from each device) of the HEMS 10 so that it is within the range of the power demand and is as close as possible to the power demand, in order to reduce the amount of power purchased at the power receiving end of the HEMS 10. In this example, the HEMS controller 15 discharges the storage battery 13. Although not shown, when the electric vehicle 12 returns from an outside location, the HEMS controller 15 may discharge the electric vehicle 12.

[0038] It is predicted that neither surplus power nor demand power will occur during the period from 10 p.m. to midnight. Therefore, the energy management server 2 returns the power management control from edge control to planned control. Therefore, the energy management server 2 takes back the control right of each device in the HEMS 10 from the HEMS controller 15.

[0039] In this manner, in the present embodiment, during a period in which the HEMS 10 is expected to sell surplus power or buy demand power, the power management control for the HEMS 10 is switched from planned control to edge control. Then, the control right of each device in the HEMS 10 is transferred to the HEMS controller 15. This enables the HEMS controller 15 to control each device in the HEMS 10 while monitoring the actual receiving end power in the HEMS 10 in real time. That is, the HEMS controller 15 can control the power (charging power, consumption power and / or discharge power) of each device in the HEMS 10 in a short time unit according to the change in the receiving end power of the HEMS 10. Therefore, according to the present embodiment, the self-consumption of the HEMS 10 can be maximized, and the amount of power bought and sold at the receiving end of the HEMS 10 can be reduced. As a result, the electricity fee for the HEMS 10 can be reduced.

[0040] <Processing flow> 3 is a flowchart showing an example of a processing procedure of power management control in this embodiment. The processing shown in this flowchart is executed when a predetermined condition is met (for example, at predetermined intervals) during execution of planned control. Each step is realized by software processing by the energy management server 2, but may also be realized by hardware (electrical circuits) arranged in the energy management server 2. Hereinafter, steps are abbreviated as S.

[0041] In S1, the energy management server 2 determines whether a trigger (hereinafter, referred to as an "update trigger") for updating the power supply and demand plan of the target HEMS 10 has occurred. For example, the update trigger occurs when a predetermined time arrives. Alternatively, for example, the update trigger may occur according to an operation by a user of the HEMS 10, or an operation by an administrator of the energy management server 2. If the update trigger occurs (YES in S1), the energy management server 2 updates the power supply and demand plan of the target HEMS 10 (S2). In other words, the control content of the plan control for maximizing the self-consumption in the HEMS 10 and minimizing the electricity bill is updated. Thereafter, the energy management server 2 proceeds to the process in S3. If the update trigger has not occurred (NO in S1), the process in S2 is skipped and the process proceeds to S3.

[0042] In S3, the energy management server 2 determines whether a trigger for determining whether or not power is being bought or sold (hereinafter, referred to as a "determination trigger") has occurred for the target HEMS 10. The determination trigger also occurs periodically, for example, when a predetermined time arrives. The determination trigger may also occur every time an update trigger occurs (i.e., every time the power supply and demand plan is updated).

[0043] When a judgment trigger occurs (YES in S3), the energy management server 2 judges whether or not at least one of the selling of surplus power and the purchasing of demanded power is predicted to occur over the target period (S4). The energy management server 2 judges, for example, whether or not a period will occur in which the power generated by the PV power generation equipment 14 increases and exceeds the power that can be consumed or stored in the HEMS 10, or a period in which the power generated by the PV power generation equipment 14 is not enough to cover the power required in the HEMS 10, based on the latest status of the devices in the HEMS 10 (e.g., changes in the stored energy state of the water heater 11, the electric vehicle 12, and the storage battery 13), the latest behavior of the consumer (e.g., increases and decreases in power consumption of various electrical appliances), the latest weather information (especially the amount of solar radiation), and the like.

[0044] If it is predicted that there will be no period in which surplus power is sold or demand power is sold during the target period (NO in S5), the energy management server 2 sets the power management control to planned control for the entire target period (S6). In this case, the energy management server 2 holds the control right of the HEMS 10 for the entire period.

[0045] On the other hand, if it is predicted that surplus power will be sold or demand power will be purchased somewhere in the target period (YES in S5), the energy management server 2 sets the power management control to edge control for the period in which the sale of surplus power and / or the purchase of demand power is predicted (S7). As a result, when the period arrives, the control right of the HEMS 10 is transferred from the energy management server 2 to the HEMS controller 15. The power management control for periods other than the above is set to planned control. As a result, when the period other than the above arrives, the control right of the HEMS 10 is returned from the HEMS controller 15 to the energy management server 2. Note that the energy management server 2 may return the power management control of the HEMS 10 to planned control during the execution of edge control in a period in which neither the sale of surplus power nor the purchase of demand power is predicted to occur.

[0046] As described above, in the present embodiment, during a period in which the HEMS 10 is expected to sell surplus power and / or buy demand power, the power management control is set to edge control, and the control rights of each device in the HEMS 10 are transferred to the HEMS controller 15. This allows the HEMS controller 15 to control each device while monitoring the receiving end power of the HEMS 10 in real time. The HEMS controller 15 can maximize the self-consumption of the HEMS 10 by closely controlling the power of each device according to changes in the receiving end power of the HEMS 10. This can reduce the amount of power bought and sold at the receiving end of the HEMS 10. In addition, when edge control is always set, charging and discharging of the devices in the HEMS 10 may be frequently switched, so by executing edge control only during a period in which the HEMS 10 is expected to sell surplus power and / or buy demand power, the power loss associated with such switching can be suppressed. Therefore, according to the present embodiment, the electricity fee for the HEMS 10 can be reduced, and the burden on the user of the HEMS 10 can be reduced.

[0047] In FIG. 2, the water heater 11, the electric vehicle 12, and the storage battery 13 are described as devices to be controlled in the switching between planned control and edge control. Controlling the water heater 11 so as to heat an optimal amount of hot water using inexpensive midnight power is particularly advantageous for self-consumption. Therefore, the water heater 11 has the highest priority as a device to be controlled. The electric vehicle 12 has a scheduled departure time and needs to be charged when out of the house so as not to run out of power, so that the electric vehicle 12 cannot be freely charged or discharged. Although conditions are imposed on charging and discharging so as not to reduce user convenience, the battery capacity of the electric vehicle 12 is also sufficiently large, so that it contributes greatly to self-consumption. In many cases, the storage battery 13 has a larger battery capacity than the electric vehicle 12. In addition, the storage battery 13 has high control flexibility in that it does not reduce user convenience. The controlled devices are not limited to the above three types of devices, and may include, for example, a fuel cell.

[0048] In addition, air conditioners and lighting devices are not suitable as controlled devices because if the temperature or brightness in a room is controlled against the user's operation, the user's comfort may be impaired. In addition, the PV power generation equipment 14 is also not suitable as a controlled device because if the PV power generation equipment 14 is controlled to suppress the amount of power generation, this may bring about an economic disadvantage (a reduction in the power selling fee) for the user.

[0049] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is defined by the claims, not by the description of the embodiments described above, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0050] 1 CEMS, 10 HEMS, 11 water heater, 12 electric vehicle, 13 storage battery, 14 PV power generation equipment, 15 HEMS controller, 2 management server, 201 processor, 202 memory, 203 communication interface, 500 power management system, 9 power system.

Claims

1. A power management system for managing power supply and demand in a power grid including a plurality of power adjustment resources, a controller for controlling a corresponding resource, which is a corresponding power adjustment resource among the plurality of power adjustment resources; a server that configures power management control by the controller for the corresponding resource; The power management control includes: A first control instructing the controller to control the corresponding resource based on a power supply and demand plan established in advance; and a second control for instructing the controller to control the corresponding resource based on an actual situation of surplus power and demand power in the corresponding resource; A power management system in which the server instructs the controller to perform the second control during a period in which at least one of the sale of surplus power and the purchase of demand power is predicted to occur in the corresponding resource while the first control is being executed.

2. The power management system according to claim 1 , wherein the server instructs the controller to perform the first control during a period during which it is predicted that neither the sale of the surplus power nor the purchase of the demanded power will occur while the second control is being executed.

3. The server, In the first control, control of the corresponding resource is maintained, while The power management system according to claim 2 , wherein in the second control, the control right is transferred to the controller.

4. Each of the plurality of power adjustment resources belongs to either a first group or a second group; the first group includes at least one of a water heater, an electric vehicle, a storage battery, and a fuel cell; the second group includes at least one of an air conditioning device, a lighting device, and a solar power generation facility; The server, A power adjustment resource belonging to the first group among the plurality of power adjustment resources is set as a control target of the first control and the second control, 4. The power management system according to claim 1, wherein a power adjustment resource belonging to the second group among the plurality of power adjustment resources is not set as a control target.

5. A power management method for managing power supply and demand in a power grid including a plurality of power regulating resources, comprising: The server configures a controller with a power management control of a corresponding resource, the corresponding resource being a corresponding power regulating resource among the plurality of power regulating resources; The power management control includes: A first control instructing the controller from the server to control the corresponding resource based on a power supply and demand plan established in advance; and a second control instructing the controller from the server to control the corresponding resource based on an actual situation of surplus power and demand power in the corresponding resource; The setting step includes: predicting whether at least one of a sale of the surplus power and a purchase of the demand power will occur in the corresponding resource during execution of the first control; and switching the power management control from the first control to the second control during a period in which at least one of the sale of the surplus power and the purchase of the demanded power is predicted to occur.

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