JP7628094B2 - Charge and discharge management system - Google Patents

Description

The present invention relates to a charge/discharge management system.

For example, Patent Document 1 discloses a power management system that enables a user who owns a battery server connected to a DC power distribution network and a public power distribution network to buy and sell power not only through the public power distribution network but also through the DC power distribution network. Patent Document 1 claims that such a power management system can eliminate power loss caused by converting DC to AC, and minimize energy loss during power buying and selling.

For example, Patent Document 2 discloses a system for a facility where power is supplied by contracted power and a power generation device that generates solar power, which calculates the times when the contracted power will be in surplus and insufficient based on the power generation plan of the power generation device and the power demand plan of the facility. The system in Patent Document 2 charges and discharges an electric vehicle based on the times when the contracted power will be in surplus and insufficient. Patent Document 2 claims that peak power can be cut by using the battery of the electric vehicle as a power buffer within the facility.

JP 2012-125063 A JP 2020-178472 A

As described in Patent Document 2, there may be times when there is an excess supply of electricity and times when there is an excess demand for electricity in the overall supply and demand situation of the power system. In order to reliably manage the supply and demand of electricity in a charge and discharge management system that manages the supply and demand of electricity in a power system, it is preferable that the storage capacity that can be used by the system is large.

The charge/discharge management system proposed here includes a setting unit capable of setting the available capacity for a preregistered battery, a detection unit that detects that the registered battery is connected to a power grid, and a control unit that controls the battery within the capacity range set by the setting unit and charges and discharges the battery through the power grid.

According to the charge/discharge management system proposed here, the charge/discharge management system can use the preset capacity of a pre-registered battery for charging/discharging via the power grid. This makes it possible to increase the storage capacity that the charge/discharge management system can use.

The charge/discharge management system proposed here may further include a granting unit that grants an incentive to a user of the battery according to the capacity set by the setting unit. In a preferred embodiment, the charge/discharge management system further includes a contract unit configured to enable a usage contract for the capacity of the battery and an incentive contract according to the usage contract, and the setting unit may set the usable capacity of the battery based on the usage contract in the contract unit, and the granting unit may grant an incentive based on the incentive contract in the contract unit. The battery may include an in-vehicle battery.

In the charge/discharge management system proposed here, the setting unit may divide the battery into a plurality of virtual batteries including a first virtual battery corresponding to the usable capacity set by the setting unit and a second virtual battery corresponding to the capacity usable by the user of the battery, and the control unit may control the first virtual battery. In addition, the charge/discharge management system proposed here may further include a regulation unit that regulates the capacity of the battery usable by the user of the battery based on the capacity set by the setting unit.

1 is a conceptual diagram showing a relationship between a charge/discharge management system according to an embodiment, a power transmission system, and batteries connected thereto. FIG. 4 is a schematic diagram showing an example of a relationship between a contracted capacity of a battery and an incentive amount. 4 is a flowchart showing a flow of charging an in-vehicle battery.

One embodiment of the charge/discharge management system disclosed herein will be described below with reference to the drawings. The embodiment described here is, of course, not intended to limit the present invention in any particular way. The present invention is not limited to the embodiment described here unless otherwise specified. Furthermore, the same reference numerals will be appropriately used for components and parts that perform the same function, and duplicate descriptions will be omitted as appropriate.

Figure 1 is a conceptual diagram showing the relationship between the charge/discharge management system 50 according to this embodiment, the power transmission system 30, and the batteries 11, 20 connected to them. Although only two examples are shown and described here, suitable examples of batteries connected to the charge/discharge management system 50 and the power transmission system 30 are the on-board battery 11 of an electric vehicle 10 parked at a home 5 and the storage battery 20 for the home 5. Other examples of batteries include on-board batteries of electric buses, electric taxis, electric boats, etc. owned by transport companies, and large-scale secondary batteries installed in offices and factories for power outage countermeasures. However, these are merely examples, and the type, use, capacity, etc. of the batteries connected to the charge/discharge management system 50 and the power transmission system 30 are not particularly limited.

In this embodiment, the electric vehicle 10 includes vehicles that use electricity as an energy source, such as electric automobiles, hybrid vehicles, and plug-in hybrid vehicles. The electric vehicle 10 may be a four-wheeled vehicle or a two-wheeled vehicle. As shown in FIG. 1, the electric vehicle 10 includes an on-board battery 11 and an ECU (Electronic Control Unit) 12 that controls the on-board battery 11. In the example shown here, the electric vehicle 10 is connected to a charging/discharging device 25 provided in a parking space of a home 5. The charging/discharging device 25 is connected to a power transmission system 30.

The storage battery 20 for the home 5 is connected to, for example, a control device 21 for the storage battery 20, a solar power generation device (not shown) installed in the home 5, an electrical device (not shown) used in the home 5, and a power transmission system 30. The storage battery 20 can store power generated by the solar power generation device. The electrical devices in the home 5 are driven by the power stored in the storage battery 20. As will be described in detail later, the capacity of the storage battery 20 and the vehicle battery 11 that can be used by the user (typically the owner, but not limited to this) of the storage battery 20 and the vehicle battery 11 is determined by contract. The user may consume the amount of power that can be freely used by the electrical devices in the home 5, or may sell the power to the manager of the charge/discharge management system 50. The user may purchase power from the power transmission system 30 until the freely usable capacity of the storage battery 20 and the vehicle battery 11 is full. The control device 21 for the storage battery 20 cooperates with the charge/discharge management system 50 to control the storage battery 20 as described above.

The charge/discharge management system 50 includes a power storage device 51. The charge/discharge management system 50 is also connected to a large number of registered batteries (e.g., the vehicle battery 11 and the storage battery 20 in FIG. 1) that have signed a contract to use a portion of the capacity via the power transmission system 30. The amount of stored power that the charge/discharge management system 50 can use is composed of the power storage device 51 and the large number of registered batteries that it manages. The charge/discharge management system 50 purchases electricity from the city, including electricity stored in electric vehicles, and stores it in the power storage device 51 and the large number of registered batteries. The electricity stored in the power storage device 51 and the large number of registered batteries is sold to a specific business such as a power company via the power transmission system 30. The charge/discharge management system 50 can be a system used to buy and sell electricity, that is, when selling and buying electricity.

Here, the system manager of the charge/discharge management system 50 is also called an aggregator. The aggregator controls the demand for electricity to maintain a balance between the demand and supply of electricity. For example, the aggregator procures electricity in response to requests from specific businesses, such as power companies, and supplies the electricity to the specific businesses. In order to secure the necessary amount of electricity, it is preferable for the aggregator to use the charge/discharge management system 50 to make contracts with more electricity managers in the city (for example, managers of electric vehicles and managers of solar power generation equipment).

As shown in FIG. 1, the charge/discharge management system 50 is connected to the ECU 12 of the electric vehicle 10 and the control device 21 of the storage battery 20 via a communication system 40. The ECU 12 and the control device 21 are controlled by the charge/discharge management system 50 via the communication system 40. In addition, the user of the electric vehicle 10 and the storage battery 20 can, for example, use a computer (not shown) connected to the ECU 12 and the control device 21 to enter into a contract with the aggregator for the purchase and sale of electricity and storage capacity. However, the user of the electric vehicle 10 and the storage battery 20 may also, for example, enter into a contract with the aggregator using a user terminal that is not connected to the ECU 12 and the control device 21.

The charge/discharge management system 50 may be realized, for example, by a server of a client-server system. The charge/discharge management system 50 may be realized by cloud computing. As shown in FIG. 1, the charge/discharge management system 50 includes a control device 55. The configuration of the control device 55 is not particularly limited. Here, the control device 55 is, for example, a microcomputer. The control device 55 includes, for example, an I/F, a CPU, a ROM, and a RAM. The charge/discharge management system 50 may be realized by a single computer, or may be realized by multiple computers working together.

As shown in FIG. 1, the control device 55 of the charge/discharge management system 50 includes a communication unit 61, a capacity setting unit 62, a contract unit 63, an incentive granting unit 64, a connection detection unit 65, a control unit 66, and a regulation unit 67. The communication unit 61 is connected to the ECU 12 of the electric vehicle 10 and the control device 21 of the storage battery 20 via the communication system 40. Although not shown, the communication unit 61 is also connected to a computer or the like used by the user of the electric vehicle 10 and the storage battery 20 via the communication system 40. The charge/discharge management system 50 contracts with the users of the electric vehicle 10 and the storage battery 20 via the communication unit 61, and manages the charging and discharging of the in-vehicle battery 11 and the storage battery 20.

The capacity setting unit 62 is configured to be able to set the usable capacity for a pre-registered battery (e.g., the in-vehicle battery 11 or the storage battery 20 in the home 5). The setting of the capacity usable by the charge/discharge management system 50 is set based on a contract between the aggregator and the user that is concluded through the contract unit 63. The contract unit 63 is configured to be able to make a contract for the use of the battery capacity. The capacity setting unit 62 sets the usable capacity of the battery based on the usage contract in the contract unit 63.

The incentive granting unit 64 grants an incentive to the user of the battery according to the capacity set by the capacity setting unit 62. The contract unit 63 is configured to be able to enter into an incentive contract according to the usage contract in addition to the usage contract for the battery capacity. The incentive granting unit 64 grants an incentive based on the incentive contract in the contract unit 63.

The connection detection unit 65 detects that the registered battery is connected to the power grid 30. For example, the vehicle battery 11 is not always connected to the power grid 30. Before using the registered battery, the connection detection unit 65 checks whether the registered battery is connected to the power grid 30. The control unit 66 controls the registered battery within the capacity range set by the capacity setting unit 62, and charges and discharges the registered battery through the power grid 30. In principle, the capacity set by the capacity setting unit 62 is not available to the user. The control device 55 includes a regulation unit 67 that regulates the capacity of the registered battery that can be used by the user based on the capacity set by the capacity setting unit 62. In addition, the charge/discharge management system 50 cannot use the capacity of the registered battery that exceeds the capacity set by the capacity setting unit 62 in principle.

As shown in FIG. 1 by way of example of the vehicle battery 11, the capacity setting unit 62 divides the vehicle battery 11 into a plurality of virtual batteries, including a first virtual battery B1 corresponding to the available capacity set by the capacity setting unit 62 and a second virtual battery B2 corresponding to the capacity available to the user of the battery. In this embodiment, the capacity setting unit 62 divides the vehicle battery 11 into a first virtual battery B1 corresponding to the available capacity Ca set by the capacity setting unit 62 and a second virtual battery B2 corresponding to the capacity Cu available to the user of the battery. Hereinafter, the capacity (full capacity) of the first virtual battery B1 is also referred to as the aggregator available capacity Ca. The capacity (full capacity) of the second virtual battery B2 is also referred to as the user available capacity Cu. Herein, the sum of the aggregator available capacity Ca and the user available capacity Cu is equal to the total capacity Ct of the vehicle battery 11 (Ca+Cu=Ct). Although illustration and description are omitted, the same applies to other registered batteries such as the storage battery 20. The control unit 66 controls the first virtual battery B1.

In this embodiment, the registered battery is divided into two virtual batteries. However, the registered battery may be divided into three or more virtual batteries. The use of the third virtual battery is not particularly limited. The third virtual battery may be, for example, a virtual battery that can be used by other aggregators. These multiple virtual batteries are a concept for making it easier to manage the capacity of the registered battery, and are not a physical division of the registered battery. As shown in FIG. 1, in the case of the vehicle battery 11, the division of the vehicle battery 11 into the virtual batteries B1 and B2 is performed, for example, as a process of the ECU 12.

Below, the flow of charging and discharging a registered battery will be explained using charging the vehicle battery 11 as an example. In order for the charge/discharge management system 50 to charge and discharge the vehicle battery 11, it is necessary that the aggregator and the manager of the vehicle battery 11 have signed a battery capacity lease contract. Based on the contract, the manager of the vehicle battery 11 allows the aggregator to use a portion of the capacity of the vehicle battery 11. In return, the manager of the vehicle battery 11 is given some kind of incentive by the aggregator. The incentive is typically a monetary incentive, such as a usage fee for the capacity of the vehicle battery 11, a discount on the charging fee for the vehicle battery 11, or an increase in the discharging fee from the vehicle battery 11.

However, the incentives given by the aggregator are not limited to monetary incentives. An incentive refers to something that is given to a user as a preferential treatment, and may be, for example, points, coupons, coupons, acquisition of products, etc. Points and coupons may be given in paper form or electronically.

Figure 2 is a schematic diagram showing an example of the relationship between the contracted capacity of the battery and the incentive amount. As shown in Figure 2, the incentive amount is preferably set so that it increases as the contracted capacity of the battery (which becomes the aggregator usable capacity Ca when the contract is concluded) increases. In the example shown in Figure 2, the incentive amount increases stepwise as the contracted capacity of the battery increases. However, the incentive amount may increase proportionally as the contracted capacity of the battery increases. The relationship between the contracted capacity of the battery and the incentive amount is not particularly limited. By setting the incentive amount to increase as the contracted capacity of the battery increases, it is expected that the total capacity of registered batteries permitted for use by the aggregator will increase.

Figure 3 is a flowchart showing the flow of charging the vehicle battery 11. The situation in which the aggregator wants to charge the first virtual battery B1 of the vehicle battery 11 is, for example, during a time period when there is low demand for electricity, such as at night. At such times, the power supply from the power transmission system 30 is excessive, so the charge/discharge management system 50 charges the registered battery with electricity to prepare for the arrival of a supply shortage situation. As shown in Figure 3, in step S01 in charging the vehicle battery 11, the charge/discharge management system 50 determines whether there is an excess supply of electricity. If the result of step S01 is NO (if there is no excess supply of electricity), charging of the first virtual battery B1 is not performed.

In step S01, for example, if it is possible to charge the first virtual battery B1 by calculating backwards from the current amount of stored power (C1, see FIG. 1) in the first virtual battery B1 and the electricity rate in the power grid 30 is low, it may be decided to charge the in-vehicle battery 11. The current amount of stored power C1 in the first virtual battery B1 is known from the previous charge/discharge and the user cannot increase or decrease it, so it can be grasped by the charge/discharge management system 50.

If the result of step S01 is YES (if there is an excess supply of power), in step S02A, it is confirmed whether the vehicle battery 11 is connected to the power grid 30. If the result of step S02A is NO (if the vehicle battery 11 is not connected to the power grid 30), charging of the vehicle battery 11 is postponed. In this case, the charge/discharge management system 50 may select charging of another registered battery. The connection confirmation of step S02A may be performed multiple times at a predetermined time interval or at any time, and charging may be selected when the connection of the vehicle battery 11 to the power grid 30 is confirmed. If the vehicle battery 11 is not connected to the power grid 30, the charge/discharge management system 50 may send a message to the user urging the connection of the electric vehicle 10 to the charge/discharge device 25.

If the result of step S02A is YES (if the in-vehicle battery 11 is connected to the power transmission system 30), in step S03A, a charge/discharge instruction is confirmed for the second virtual battery B2 used by the user. If the result of step S03A is YES (if the second virtual battery B2 is also to be charged), in step S04A, the charge/discharge management system 50 commands the ECU 12 to charge the first virtual battery B1 and the second virtual battery B2. If the result of step S03A is NO (if the second virtual battery B2 is not to be charged), in step S04C, the charge/discharge management system 50 commands the ECU 12 to charge only the first virtual battery B1.

3, even if the result of step S01 is NO (when there is no excess power supply), in step S02B, it is confirmed whether the vehicle battery 11 is connected to the power transmission system 30. Step S02B is a step for determining whether the second virtual battery B2 used by the user can be charged. If the result of step S02B is NO (when the vehicle battery 11 is not connected to the power transmission system 30), the vehicle battery 11 is not charged. If the result of step S02B is YES (when the vehicle battery 11 is connected to the power transmission system 30), in the following step S03B, an instruction to charge and discharge the second virtual battery B2 is confirmed. In the following, the amount of stored power before charging of the second virtual battery B2 is C2 (see FIG. 1). If the result of step S03B is YES, in step S04B, the charge and discharge management system 50 issues a command to charge only the second virtual battery B2. If the result of step S03B is NO, the vehicle battery 11 is not charged.

When charging only the second virtual battery B2 used by the user in step S04B, charging of the in-vehicle battery 11 is performed until the amount of stored power becomes equal to the sum of C1 (the amount of stored power in the first virtual battery B1 before charging) and Cu (the capacity of the second virtual battery B2 = the fully charged amount). All the power charged at this time is treated as having been sold to the user. As a result, the amount of charge in the second virtual battery B2 is treated as being fully charged.

When charging only the first virtual battery B1 used by the aggregator in step S04C, charging of the in-vehicle battery 11 is performed until the amount of stored power becomes equal to the sum of C2 (the amount of stored power in the second virtual battery B2 before charging) and Ca (the capacity of the first virtual battery B1 = the fully charged amount). All the power charged at this time is treated as having been stored by the aggregator. As a result, the amount of charge in the first virtual battery B1 is treated as being fully charged.

When both the first virtual battery B1 and the second virtual battery B2 are charged in step S04A, the current I flowing through the vehicle battery 11 is treated as being distributed in proportion to the capacity Ca of the first virtual battery B1 and the capacity Cu of the second virtual battery B2 until either one is treated as being full. That is, the first virtual battery B1 is treated as having a charge of I.t.Ca/(Ca+Cu) with t being the charging time. The second virtual battery B2 is treated as having a charge of I.t.Cu/(Ca+Cu). After either the first virtual battery B1 or the second virtual battery B2 is treated as being full, only the virtual battery that is still charging is treated as being charged. The above calculation is the same as the calculation when the physically separated first battery and second battery are connected in parallel (no current flows through the full battery). Therefore, by assuming a first virtual battery B1 and a second virtual battery B2, it is possible to easily distinguish between the charging and discharging of the aggregator and the charging and discharging of the user in terms of calculations.

In the example of Figure 3, the case of charging the vehicle battery 11 is described, but the same applies to discharging. One example of a situation in which it is desirable to discharge a registered battery is a situation in which a shortage of electricity from renewable energy is expected due to weather or other conditions.

In this way, the charge/discharge management system 50 according to this embodiment includes a capacity setting unit 62 capable of setting the available capacity Ca for a preregistered battery (for example, the vehicle battery 11 or the storage battery 20 of the home 5), a connection detection unit 65 for detecting that the registered battery is connected to the power transmission system 30, and a control unit 66 for controlling the battery within the range of the capacity Ca set by the capacity setting unit 62 and charging/discharging the battery through the power transmission system 30. With this configuration, the charge/discharge management system 50 can use the preregistered capacity Ca (aggregator available capacity Ca) for charging/discharging via the power transmission system 30. This allows the storage capacity available to the charge/discharge management system 50 to be increased. When the storage capacity available to the charge/discharge management system 50 is increased, the amount of power available for adjusting the supply and demand of power increases, so that the supply and demand of power can be adjusted more reliably.

In addition, if the increase in the storage capacity of the charge/discharge management system 50 were to depend on the storage device 51, the amount of capital investment would be large and the preparation period would be long. According to this embodiment, such capital investment and preparation period can be reduced.

In this embodiment, the charge/discharge management system 50 further includes an incentive granting unit 64 that grants incentives to battery users according to the aggregator usable capacity Ca set by the capacity setting unit 62. This makes it possible to increase the number of users who provide a portion of the capacity of the managed battery as the aggregator usable capacity Ca. Here, the charge/discharge management system 50 aims to secure the aggregator usable capacity Ca by granting incentives to battery users.

Specifically, the charge/discharge management system 50 according to this embodiment includes a contract unit 63 that is configured to enable a usage contract for the battery capacity and an incentive contract according to the usage contract. The capacity setting unit 62 sets the usable capacity Ca of the battery based on the usage contract in the contract unit 63, and the incentive granting unit 64 grants an incentive based on the incentive contract in the contract unit 63. Such a charge/discharge management system 50 allows for smooth contracts with users.

In this embodiment, the capacity setting unit 62 divides the battery into a plurality of virtual batteries including a first virtual battery B1 corresponding to the aggregator usable capacity Ca set by the capacity setting unit 62 and a second virtual battery B2 corresponding to the user usable capacity Cu that can be used by the user of the battery, and the control unit 66 controls the first virtual battery B1. According to such a charge/discharge management system 50, the virtual battery can be treated in the same way as a physically divided battery, so that it is easy to calculate the distribution of charge/discharge amounts to the virtual batteries.

In this embodiment, a regulating unit 67 is provided that regulates the battery capacity Cu that can be used by the battery user based on the aggregator usable capacity Ca set by the capacity setting unit 62. According to the regulation by the regulating unit 67, the user can only consume battery power until the remaining capacity of the second virtual battery B2 is depleted, and can only increase the amount of stored power of the battery that can be used by the user himself/herself until the second virtual battery B2 is full (user usable capacity Cu). This allows the aggregator to reliably secure the aggregator usable capacity Ca.

However, in an emergency, the user may be able to use the power of the aggregator usable capacity Ca by following a prescribed procedure. The contents of the contract between the aggregator and the user may be changed at any time. For example, when traveling far away with the electric vehicle 10, the user may be able to change the user usable capacity Cu to a larger one or to transfer part or all of the user usable capacity Cu to the storage battery 20 of the home 5. However, from the viewpoint of predictability of the aggregator usable capacity Ca, certain restrictions may be imposed on the change. The charge/discharge management system 50 may be configured to impose a penalty (e.g., a reduction in the incentive) on a contract change that is more abrupt than a predetermined notice period (e.g., the emergency use of the power of the aggregator usable capacity Ca described above).

In this embodiment, the registered batteries include the vehicle battery 11. The vehicle battery 11 has a relatively large capacity so that the electric vehicle 10 can travel long distances. However, there are few situations in daily life where a large amount of stored electricity is required, and the situations where a large amount of stored electricity is required are often known in advance. Therefore, a relatively large aggregator usable capacity Ca can be obtained from the vehicle battery 11. In addition, there are many vehicle batteries 11. Therefore, by registering the vehicle battery 11, the total amount of aggregator usable capacity Ca that can be secured by the charge/discharge management system 50 can be efficiently increased.

A preferred embodiment of the present invention has been described above. However, the embodiment does not limit the present invention unless otherwise specified.

5 Home 10 Electric vehicle 11 Vehicle battery (battery)
20. Battery
21 Control device 25 Charging/discharging device 30 Power transmission system 40 Communication system 50 Charging/discharging management system 51 Power storage device 55 Control device 61 Communication unit 62 Capacity setting unit (setting unit)
63 Contract section 64 Incentive granting section (granting section)
65 Connection detection unit (detection unit)
66 Control unit 67 Restriction unit B1 First virtual battery B2 Second virtual battery Ca Aggregator available capacity Cu User available capacity Ct Total capacity of the vehicle battery

Claims (4)

A setting unit capable of setting a usable capacity for a preregistered battery;
A detection unit that detects that the registered battery is connected to a power grid;
a control unit that controls the battery within the capacity range set by the setting unit and charges and discharges the battery through the power transmission system,
The battery includes an on-board battery of an electric vehicle,
If the on-board battery is not connected to the power grid, a message is sent to a user of the electric vehicle prompting the user to connect the electric vehicle to the power grid;
the setting unit divides the battery into a plurality of virtual batteries including a first virtual battery corresponding to a usable capacity set by the setting unit and a second virtual battery corresponding to a usable capacity of the battery by a user;
the control unit controls the first virtual battery , and when simultaneously charging and discharging both the first virtual battery and the second virtual battery, processes the charging and discharging amounts of the first virtual battery and the second virtual battery as being distributed in proportion to their respective capacities.
Charge and discharge management system. The battery further includes a granting unit that grants an incentive to a user of the battery according to the capacity set by the setting unit.
The charge/discharge management system according to claim 1 . A contract unit configured to be able to enter into a contract for use of the capacity of the battery and an incentive contract according to the contract for use,
the setting unit sets a usable capacity of the battery based on a usage contract in the contract unit;
The granting unit grants an incentive based on the incentive contract in the contract unit.
The charge/discharge management system according to claim 2 . The battery may further include a regulating unit that regulates a capacity of the battery that can be used by a user of the battery based on the capacity set by the setting unit.
The charge/discharge management system according to any one of claims 1 to 3 .

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