Virtual Power Plant Power Management System

Abstract

To provide a power management system of a virtual power plant, which can determine a reference value of adjustment force of power supply-demand balance and bidding price in a power supply-demand adjustment market while minimizing an impact on revenues of a user in the power supply-demand adjustment market without damaging convenience of the user.SOLUTION: A power management system of a virtual power plant is the power management system of the virtual power plant, which controls only charging operation of an on-vehicle battery connected to a charger. The system includes a power management device for setting a reference value and bidding price of a charged power amount of the on-vehicle battery, which becomes a reference of adjustment force of power supply-demand balance, on the basis of presence or absence of use schedule of a vehicle, maximum charge power of a charger and available capacity of the on-vehicle battery, and controlling charge operation of the on-vehicle battery on the basis of the set reference value and the bidding price.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a power management system for a virtual power plant (VPP) that controls only the charging operation of an on-board battery connected to a charger. [Background technology]

[0002] Patent Document 1 describes a power management system that has multiple adjacent microgrids, each including a power generation facility that generates electricity using natural energy and a power consumption facility that is installed within a specified area and consumes the power generated by the power generation facility, and controls the charging and discharging operations of the secondary batteries of electric vehicles in each microgrid. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-114090 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been growing interest in operating electric vehicles as part of a VPP by linking their battery storage functions with the power infrastructure and optimizing the charge / discharge amount and timing of the onboard batteries. VPPs can be divided into two types: Vehicle-to-Grid (V2G) and Vehicle-to-Grid (V1G). While V2G systems can control the charging and discharging of onboard batteries, V1G systems can only control the charging of onboard batteries. Therefore, V1G VPPs can provide power supply and demand balancing by setting a fixed reference value for the onboard battery's charging power and increasing or decreasing the onboard battery's charging power relative to the reference value. However, the amount of power that can be charged to the onboard battery is limited by its capacity and remaining capacity. Furthermore, from the perspective of user convenience, the onboard battery must have sufficient remaining capacity when using an electric vehicle. For this reason, in order to provide the ability to adjust the power supply and demand balance without compromising user convenience, there was a need for technology that would determine the base value for the power supply and demand balance adjustment ability and the bid price in the power supply and demand adjustment market, taking into account the constraints of onboard batteries and user schedules.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a power management system for a virtual power plant that can determine a reference value for the adjustment capacity of the power supply and demand balance and a bid price in the power supply and demand adjustment market, without compromising user convenience and while minimizing the impact on users' profits in the power supply and demand adjustment market. [Means for solving the problem]

[0006] The power management system of a virtual power plant according to the present invention is a power management system of a virtual power plant that controls only the charging operation of an onboard battery connected to a charger, and is characterized by having a power management device that sets a reference value and a bid value for the amount of charging energy for the onboard battery, which serve as the basis for adjusting the balance between power supply and demand, based on whether or not the vehicle is scheduled to be used, the maximum charging power of the charger, and the available capacity of the onboard battery, and controls the charging operation of the onboard battery based on the set reference value and bid value.

[0007] In the power management system for a virtual power plant according to the present invention, in the above invention, the power management device does not set bid prices for time slots when vehicles are scheduled to be used, thereby preventing a loss of user convenience due to bidding being performed when vehicles are scheduled to be used.

[0008] In the power management system for a virtual power plant according to the present invention, in the above invention, the power management device, when the amount of charged power of the onboard battery in a time frame in which the vehicle is scheduled to be used is less than the required amount, changes the bid prices for time frames prior to that time frame in order from the time frame with the lowest bid price, thereby improving user convenience while minimizing the impact on user revenues in the power supply and demand adjustment market.

[0009] In the power management system for a virtual power plant according to the present invention, the power management device sets a bid price for a time slot when the vehicle is not scheduled to be used based on the smaller of the maximum charging power of the charger or the amount of charging power that fills the available capacity of the on-board battery. This makes it possible to bid at the highest possible price and maximize the profits that can be obtained. [Effects of the Invention]

[0010] According to the power management system of the virtual power plant of the present invention, a reference value for the amount of charging energy for the onboard battery, which serves as the basis for the power supply and demand balance adjustment capability, and a bid value are set based on whether or not the vehicle is scheduled to be used, the maximum charging power of the charger, and the available capacity of the onboard battery. This makes it possible to determine the reference value for the power supply and demand balance adjustment capability and the bid value in the power supply and demand adjustment market without compromising user convenience and while minimizing the impact on users' profits in the power supply and demand adjustment market. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a block diagram showing the configuration of a power management system for a virtual power plant according to an embodiment of the present invention. [Figure 2]FIG. 2 is a flowchart showing the flow of power management processing according to an embodiment of the present invention. [Figure 3] FIG. 3 is a flowchart showing the flow of the charge amount correction process according to one embodiment of the present invention. [Figure 4] FIG. 4 is a diagram for explaining the process of step S24 shown in FIG. [Figure 5] FIG. 5 is a diagram showing an example of the reference value and bid price for the amount of battery charging energy for each frame. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a power management system for a virtual power plant according to one embodiment of the present invention will be described in detail with reference to the drawings.

[0013] 〔composition〕 First, with reference to FIG. 1, the configuration of a power management system for a virtual power plant according to one embodiment of the present invention will be described.

[0014] Fig. 1 is a block diagram showing the configuration of a power management system for a virtual power plant according to one embodiment of the present invention. As shown in Fig. 1, the power management system for a virtual power plant according to one embodiment of the present invention is a V1G type power management system for a virtual power plant that controls only the charging operation of a battery (on-board battery) 14a of a vehicle 14 connected to a charger 13 using power supplied from a power company 11 via a power grid 12. In this embodiment, the power management system includes a power management device 1 that controls the charging operation of the battery 14a by the charger 13.

[0015] The power management device 1 is configured with an information processing device such as a workstation, and is connected to a charger 13 and a power supply and demand adjustment server device 15 via a telecommunications line such as the Internet. Here, the power supply and demand adjustment server device 15 is a device that manages power transactions in the power supply and demand adjustment market, and provides information about power bidding via the telecommunications line. The information about power bidding includes information such as the expected unit price for power buying and selling for each bidding time frame (for example, the buying and selling price for 1 kW of power).

[0016] The power management device 1 also has a user information database (user information DB) 1a. User information DB 1a stores user information such as that shown in Table 1 below for each user who uses the power management system. Specifically, as shown in Table 1, the user information includes a bid presence / absence Flag(i) for each bid frame i (=1 to Imax (48 in this example)), a reference value L(i) for the amount of energy charged to battery 14a, an amount of energy Ca(i) charged to battery 14a, an expected unit price Pr(i) for the bid, whether or not the vehicle 14 is scheduled to be used, and information regarding the amount of energy required to charge (required capacity) Cr(i) of battery 14a.

[0017] [Table 1]

[0018] Here, when the value of the bid presence / absence Flag(i) is 1, it indicates that there are no plans to use the vehicle 4, in other words, that a bid will be submitted, and when the value is 0, it indicates that there are plans to use the vehicle 4, in other words, that a bid will not be submitted. Furthermore, the required capacity Cr(i) of the battery 14a is set to 0 if there are no plans to use the vehicle 14, and is set to a value according to the intended use of the vehicle 14 if there are plans to use the vehicle 14. Furthermore, the user information includes information such as the user's identification information, information about the vehicle 14 owned by the user, the maximum capacity Cmax of the battery 14a installed in the vehicle 14 owned by the user, and the maximum charging power Pmax of the charger 13 to which the battery 14a is connected. The user information is registered via a telecommunications line by users who use the power management system and is stored in the user information DB 1a in a rewritable form.

[0019] In a power management system having such a configuration, the power management device 1 executes the power management process described below using information related to power bids and user information to determine the reference value for the power supply and demand balance adjustment capability and the bid price in the power supply and demand adjustment market without impairing user convenience and while minimizing the impact on users' profits in the power supply and demand adjustment market. Below, with reference to Figure 2, the operation of the power management device 1 when executing the power management process will be described.

[0020] [Power management processing] Figure 2 is a flowchart showing the flow of power management processing according to one embodiment of the present invention. The flowchart shown in Figure 2 starts when a command to execute power management processing for a processing period (frame i (=1 to Imax)) is input to the power management apparatus 1, and the power management processing proceeds to processing in step S1. Note that the power management processing described below is executed for each user whose user information is stored in the user information DB 1a. Furthermore, the operation of the power management apparatus 1 described below is realized by the power management apparatus 1 executing a computer program.

[0021] In the processing of step S1, the power management device 1 sets the value of the program counter i, which indicates the frame number to be processed, to 1 (the frame number corresponding to the first frame of the processing period ("0:00" in the example shown in Table 1)). This completes the processing of step S1, and the power management processing proceeds to the processing of step S2.

[0022] In the processing of step S2, the power management device 1 determines whether the value of the program counter i is equal to or less than imax (the frame number corresponding to the last frame of the processing period ("23:30" in the example shown in Table 1)). If the result of the determination is that the value of the program counter i is equal to or less than imax (step S2: Yes), the power management device 1 proceeds with the power management processing to the processing of step S3. On the other hand, if the value of the program counter i is equal to imax (step S2: No), the power management device 1 determines that processing has been completed for all frames within the processing period, and ends the series of power management processing.

[0023] In the processing of step S3, the power management device 1 reads user information for the processing period from the user information DB 1a, and determines, based on the read user information, whether or not the bid presence / absence Flag(i) for the frame corresponding to the value of the program counter i is set to 1. If the result of the determination is that the bid presence / absence Flag(i) is set to 1 (step S3: Yes), the power management device 1 determines that the vehicle 14 is not scheduled to be used, and proceeds with the power management processing to the processing of step S6. On the other hand, if the bid presence / absence Flag(i) is set to 0 (step S3: No), the power management device 1 determines that the vehicle 14 is scheduled to be used, and proceeds with the power management processing to the processing of step S4.

[0024] In step S4, the power management device 1 determines whether the remaining capacity C(i) of the battery 14a at the start of the frame set in the previous power management process is greater than the required capacity Cr(i) of the battery 14a included in the user information. If this is the first time the power management process is being performed, the power management device 1 obtains the remaining capacity C(i) of the battery 14a installed in the user's vehicle 14 connected to the charger 13 via a telecommunications line, based on the user information read in step S3. Alternatively, the user may input the remaining capacity C(i) of the battery 14a. If the determination results in the remaining capacity C(i) of the battery 14a being greater than the required capacity Cr(i) of the battery 14a (step S4: Yes), the power management device 1 proceeds to step S10. On the other hand, if the remaining capacity C(i) of the battery 14a is equal to or less than the required capacity Cr(i) of the battery 14a (step S4: No), the power management device 1 proceeds to step S5.

[0025] In the process of step S5, the power management device 1 executes a charge amount correction process to correct the amount of energy charged to the battery 14a so that the remaining capacity C(i) of the battery 14a becomes equal to the required capacity Cr(i) of the battery 14a. Details of this charge amount correction process will be described later with reference to the flowchart shown in Figure 3. This completes the process of step S5, and the power management process proceeds to the process of step S10.

[0026] In the process of step S6, the power management device 1 calculates, based on the user information, the difference Cmax-C(i) between the maximum capacity Cmax of the battery 14a and the remaining capacity C(i) of the battery 14a, divided by the time T for one frame, as the amount of charging energy {Cmax-C(i)} / T that will fill the available capacity of the battery 14a. Then, based on the user information, the power management device 1 determines whether the maximum amount of charging energy Pmax of the charger 13 is greater than the amount of charging energy {Cmax-C(i)} / T. If the result of the determination is that the maximum amount of charging energy Pmax of the charger 13 is greater than the amount of charging energy {Cmax-C(i)} / T (step S6: Yes), the power management device 1 proceeds with the power management process to the process of step S7. On the other hand, if the maximum amount of charging energy Pmax of the charger 13 is equal to or less than the amount of charging energy {Cmax-C(i)} / T (step S6: No), the power management device 1 proceeds with the power management process to the process of step S8.

[0027] In the process of step S7, the power management device 1 sets the reference value L(i) of the amount of charging energy for the battery 14a and the bid value B(i) to a value obtained by dividing the amount of charging energy {Cmax-C(i)} / T by 2, and sets the amount of charging energy Ca(i) for the battery 14a to a value obtained by multiplying the reference value L(i) of the amount of charging energy for the battery 14a by the time T for one frame. Note that the bid value B(i) refers to the range of charging power that can be controlled relative to the reference value L(i) in frame i. For example, if the charging power can be controlled between 0 and 6 kW relative to the reference value of 3 kW, the bid value B(i) will be ±3 kW. This completes the process of step S7, and the power management process proceeds to the process of step S9.

[0028] In the process of step S8, the power management device 1 sets the reference value L(i) of the charge amount of the battery 14a and the bid price B(i) to a value obtained by dividing the maximum charge energy amount Pmax of the charger 13 by 2, and sets the charge energy amount Ca(i) of the battery 14a to a value obtained by multiplying the reference value L(i) of the charge energy amount of the battery 14a by the time T for one frame. This completes the process of step S8, and the power management process proceeds to the process of step S9.

[0029] In the process of step S9, the power management device 1 sets the remaining capacity C(i+1) of the battery 14a at the start of the next frame (frame number i+1) to a value obtained by adding the remaining capacity C(i) of the battery 14a at the start of the current frame (frame number i) to the amount of charging energy Ca(i) of the battery 14a set in the process of step S7 or step S8. This completes the process of step S9, and the power management process proceeds to the process of step S10.

[0030] In the process of step S10, the power management device 1 increments the value of the program counter i by 1. This completes the process of step S10, and the power management process proceeds to the process of step S10. Thereafter, the power management device 1 controls the charging operation of the battery 14a based on the reference value L(i) of the amount of charging energy of the battery 14a and the bid price B(i) set in the process of step S7 or step S8.

[0031] [Charge amount correction process] Next, the charge amount correction process in step S5 will be described in detail with reference to FIG.

[0032] Fig. 3 is a flowchart showing the flow of the charge amount correction process in step S5 shown in Fig. 2. The flowchart shown in Fig. 3 starts when it is determined in the process of step S4 shown in Fig. 2 that the remaining capacity C(i) of the battery 14a is equal to or less than the required capacity Cr(i) of the battery 14a, and the charge amount correction process proceeds to the process of step S21.

[0033] In the process of step S21, the power management device 1 calculates the difference between the required capacity Cr(i) of the battery 14a and the remaining capacity C(i) of the battery 14a as the insufficient charge amount (deficit amount) Cd(i). This completes the process of step S21, and the charge amount correction process proceeds to the process of step S22.

[0034] In the process of step S22, the power management device 1 searches for the frame number j of the frame with the smallest expected bid price Pr(i) from among the frames with a start time earlier than the start time of the frame corresponding to frame number i, based on the user information. This completes the process of step S22, and the charge amount correction process proceeds to the process of step S23.

[0035] In step S23, the power management device 1 determines whether the shortage Cd(i) calculated in step S21 is greater than the value obtained by subtracting the charging energy Ca(j) of the battery 14a in the frame corresponding to the frame number j found in step S22 from Pmax*T, which is the product of the maximum charging energy Pmax of the charger 13 and the time T for one frame. If multiple frame numbers are found in step S22, the power management device 1 selects the frame number corresponding to the frame with the earliest start time among the found frame numbers as frame number j. If the determination results in the shortage Cd(i) being greater than the subtraction value (step S23: Yes), the power management device 1 determines that even the maximum charging energy Pmax cannot make up for the shortage Cd(i), and proceeds to step S25 in the charging amount correction process. On the other hand, if the shortage Cd(i) is less than or equal to the subtraction value (step S23: No), the power management device 1 determines that the shortage Cd(i) can be compensated for by the maximum charging energy amount Pmax, and proceeds with the charging amount correction process to step S24.

[0036] In the process of step S24, the power management device 1 sets the reference value L(j) of the amount of charging energy of the battery 14a in the frame corresponding to the frame number j found in the process of step S22 to a value obtained by adding Cd(i) / T, which is the value obtained by dividing the shortage Cd(i) by the time T for one frame, to the reference value L(j). The power management device 1 also sets the bid price B(j) for the frame corresponding to the frame number j to a value obtained by subtracting the reference value L(j) from the maximum amount of charging energy Pmax of the charger 13, and sets the amount of charging energy Ca(j) of the battery 14a in the frame corresponding to the frame number j to a value obtained by adding the shortage Cd(i) to the amount of charging energy Ca(j). That is, as shown in FIG. 4, the power management device 1 corrects the reference value L(j) of the amount of charging energy of the battery 14a so that only the shortage Cd(i) is additionally charged. This completes the process of step S24, and the charge amount correction process proceeds to the process of step S26.

[0037] In the process of step S25, the power management device 1 sets the value of the bid presence / absence Flag(j) for the frame corresponding to frame number j found in the process of step S22 to 0, thereby setting so that bidding will not be held for the frame corresponding to frame number j. Furthermore, the power management device 1 sets the reference value L(j) of the amount of charging energy for the battery 14a in the frame corresponding to frame number j found in the process of step S22 to the maximum charging energy Pmax of the charger 13, and sets the bid value B(j) for the frame corresponding to frame number j found in the process of step S22 to 0. Furthermore, the power management device 1 sets the amount of charging energy Ca(j) for the battery 14a in the frame corresponding to frame number j to a value obtained by multiplying the reference value L(j) by the time T for one frame. This completes the process of step S25, and the charge amount correction process proceeds to the process of step S26.

[0038] In the process of step S26, the power management device 1 sets the remaining capacity C(j+1) of the battery 14a at the start of the frame next to the frame corresponding to frame number j (frame number j+1) to a value obtained by adding the remaining capacity C(j) of the battery 14a at the start of the frame corresponding to frame number j to the amount of charging energy Ca(j) of the battery 14a set in the process of step S24 or step S25. This completes the process of step S26, and the charge amount correction process proceeds to the process of step S27.

[0039] In the process of step S27, the power management device 1 increments the value of the frame number j by 1. This completes the process of step S27, and the charge amount correction process proceeds to the process of step S .

[0040] In the process of step S28, the power management device 1 determines whether the value of frame number j has become the same as frame number i. If the result of the determination is that the value of frame number j has become the same as frame number i (step S28: Yes), the power management device 1 advances the charge amount correction process to the process of step S29. On the other hand, if the value of frame number j has not become the same as frame number i (step S28: No), the power management device 1 returns the charge amount correction process to the process of step S26.

[0041] In the process of step S29, the power management device 1 determines whether the remaining capacity C(i) of the battery 14a in the frame corresponding to frame number i is the same as the required capacity Cr(i) of the battery 14a in the frame corresponding to frame number i. If the result of the determination is that the remaining capacity C(i) is the same as the required capacity Cr(i) (step S29: Yes), the power management device 1 ends the series of charge amount correction processes. On the other hand, if the remaining capacity C(i) is not the same as the required capacity Cr(i) (step S29: No), the power management device 1 returns the charge amount correction process to the process of step S21.

[0042] As is clear from the above explanation, in the power management system of a virtual power plant that is one embodiment of the present invention, as shown in Figure 5, the power management device 1 sets a reference value for the amount of energy charged to battery 14a, which serves as a basis for the ability to adjust the balance between supply and demand, and a bid price, based on whether or not the vehicle 14 is scheduled to be used, the maximum charging power of charger 13, and the available capacity of battery 14a.This makes it possible to determine the reference value for the ability to adjust the balance between supply and demand and a bid price in the power supply and demand adjustment market without impairing user convenience and while minimizing the impact on users' profits in the power supply and demand adjustment market.In Figure 5, line L1 represents the reference value for the amount of energy charged to battery 14a, and line L2 represents the bid price.

[0043] Furthermore, in the power management system of a virtual power plant, which is one embodiment of the present invention, the power management device 1 does not set a bid price for a time slot when the vehicle 14 is scheduled to be used, thereby preventing a loss of user convenience due to bidding being made when the vehicle 14 is scheduled to be used.

[0044] Furthermore, in the power management system of a virtual power plant, which is one embodiment of the present invention, if the amount of charged power in battery 14a during a time frame in which vehicle 14 is scheduled to be used is less than the required amount, power management device 1 changes the bid prices for time frames prior to that time frame in order from the time frame with the lowest bid unit price, thereby improving user convenience while minimizing the impact on user revenues in the power supply and demand adjustment market.

[0045] Furthermore, in the power management system of a virtual power plant, which is one embodiment of the present invention, the power management device 1 sets the bid value for a time slot when the vehicle 14 is not scheduled to be used based on the smaller of the maximum charging power of the charger 13 or the amount of charging power that fills the available capacity of the battery 14a, so that the maximum possible bid can be made, maximizing the profits that can be obtained.

[0046] Although the present invention has been described above as an embodiment, the present invention is not limited to the description and drawings that form part of the disclosure of the present invention. In other words, other embodiments, examples, and operational techniques that can be made by those skilled in the art based on the present invention are all included in the scope of the present invention. [Explanation of symbols]

[0047] 1 Power management device 1a User Information Database (User Information DB) 11. Electric power companies 12 Power system 13 Charger 14 vehicles 14a battery 15. Electricity supply and demand adjustment server device

Claims

1. A power management system of a virtual power plant that controls only the charging operation of an on-board battery connected to a charger, a power management device that sets a reference value for the amount of charging power of the on-board battery, which serves as a reference for the ability to adjust the balance between power supply and demand, and a bid value that is a range of the amount of charging power that can be controlled relative to the reference value, based on whether or not the vehicle is scheduled to be used, the maximum charging power of the charger, and the available capacity of the on-board battery, and controls the charging operation of the on-board battery based on the set reference value and bid value; The power management device If the maximum charging energy amount of the charger is greater than the charging energy amount that satisfies the available capacity of the vehicle battery, the reference value and the bid price are set to a value obtained by dividing the charging energy amount that satisfies the available capacity of the vehicle battery by two; When the maximum charging energy amount of the charger is equal to or less than the charging energy amount that satisfies the free capacity of the in-vehicle battery, the reference value and the bid price are set to a value obtained by dividing the maximum charging energy amount of the charger by two. A power management system for a virtual power plant.

2. The power management system for a virtual power plant according to claim 1 , wherein the power management device does not set a bid price for a time slot in which a vehicle is scheduled to be used.

3. 2. The power management system for a virtual power plant according to claim 1, wherein, when the amount of charged power of the onboard battery in a time frame in which the vehicle is scheduled to be used is less than the required amount, the power management device changes the bid prices for time frames prior to that time frame in order from the time frame with the lowest bid unit price.

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