Charge and discharge management system
The charge and discharge management system optimizes electric vehicle fleet operations by setting priority orders based on SOC and SOH to manage discharge and charge processes, addressing battery degradation and ensuring capacity, thereby enhancing energy efficiency and sustainability.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- HONDA MOTOR CO LTD
- Filing Date
- 2024-12-13
- Publication Date
- 2026-06-18
AI Technical Summary
Existing charge and discharge management systems for electric vehicle fleets connected to a power grid face challenges in balancing power generation and consumption while minimizing battery degradation, as stringent conditions limit eligible vehicles and relaxed conditions accelerate degradation.
A charge and discharge management system that includes a battery information acquirer, participant configurator, priority configurator, and discharge/charge controller to manage electric vehicle fleets by setting priority orders based on State of Charge (SOC) and State of Health (SOH) to optimize discharge and charge processes, preventing excessive depth of discharge/charge and ensuring vehicles are not used immediately after charging/discharging.
The system effectively responds to power grid demands by prioritizing vehicles with higher SOC and SOH for discharge/charge, preventing battery degradation and ensuring capacity is maintained, thus contributing to a sustainable transport system.
Smart Images
Figure JP2024044295_18062026_PF_FP_ABST
Abstract
Description
CHARGE AND DISCHARGE MANAGEMENT SYSTEM
[0001] The present invention relates to a charge and discharge management system. More specifically, the present invention relates to a charge and discharge management system for an electric vehicle fleet connected to a power grid.
[0002] In recent years, research and development has been conducted on charge and discharge in battery-equipped moving bodies that contribute to energy efficiency in order to ensure that more people have access to affordable, reliable, sustainable, and advanced energy.
[0003] In order for a power grid to operate properly, there must be a balance between power generation and power consumption. A significant imbalance between power generation and power consumption may lead to a grid failure. Patent Document 1 describes an invention related to a vehicle-to-grid (V2G) that uses excess battery storage capacity of electric vehicles such as battery electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs), to stabilize the power grid. This helps to reduce the imbalance between power generation and power consumption in the power grid by charging electric vehicles at low rates during off-peak hours and discharging from electric vehicles to the power grid during high-peak hours.
[0004] [PLT 1] United States Patent Application Publication, No. US 2016 / 280089 A1Problems to be Solved by the Invention
[0005] Incidentally, the invention described in Patent Document 1 defines electric vehicles that meet specific conditions regarding location, state of charge (SOC), previous V2G history, distance from charge station, number of discharge cycles, cruising range, battery condition, and battery degradation as vehicles to participate in V2G transfer. This prevents battery degradation in electric vehicles participating in V2G transfer.
[0006] However, if the conditions are made strict, the number of electric vehicles that are eligible to participate in V2G transfer may be limited, and the demand from the power grid may not be adequately met. On the other hand, relaxing the conditions may accelerate battery degradation.
[0007] It is an object of the present invention to provide a charge and discharge management system that makes it possible to suppress battery degradation while responding to the demand from the power grid, and to thereby contribute to development of a sustainable transport system.Means for Solving the Problems
[0008] (1) One aspect of the present invention is to a charge and discharge management system for managing charge and discharge of an electric vehicle fleet connected to a power grid via charge and discharge facilities, including: a battery information acquirer configured to acquire battery information including an SOC of an on-board battery of an individual vehicle constituting the electric vehicle fleet; a participant configurator configured to set a plurality of vehicles satisfying a predetermined condition from among the electric vehicle fleet as discharge participants; a priority configurator configured to set a priority order corresponding to an order of discharge to the power grid for a plurality of the discharge participants based on the SOC of the on-board battery; a charge and discharge controller configured to select at least one of a plurality of the discharge participants in descending order of the priority order and to cause the selected vehicle to discharge to the power grid when a discharge request is generated by the power grid; and a discharge depth calculator configured to calculate a depth of discharge of the on-board battery based on the battery information. The charge and discharge controller terminates discharge of a vehicle during discharge when the depth of discharge of the on-board battery reaches a predetermined threshold value, and starts discharge of a vehicle in next priority order.
[0009] (2) According to the above aspect, the priority configurator sets the priority order for a plurality of the discharge participants in descending order of the SOC of the on-board battery.
[0010] (3) According to the above aspect, the battery information includes an SOH corresponding to health of the on-board battery, and the priority configurator sets the priority order for a plurality of the discharge participants based on the SOC and the SOH of the on-board battery.
[0011] (4) According to the above aspect, the participant configurator sets a vehicle with the SOC of the on-board battery higher than a discharge allowable threshold as the discharge participant among a plurality of vehicles constituting the electric vehicle fleet, and the charge and discharge controller terminates discharge of a vehicle during discharge when the depth of discharge of the on-board battery reaches the threshold value, even if the SOC of the on-board battery is higher than the discharge allowable threshold.
[0012] (5) According to the above aspect, the participant configurator sets a vehicle that does not elapse a predetermined charge / discharge waiting period after charging or discharging the on-board battery until the depth of discharge reaches the threshold value as a discharge non-participant.
[0013] (6) One aspect of the present invention is to a charge and discharge management system for managing charge and discharge of an electric vehicle fleet connected to a power grid via charge and discharge facilities, including: a battery information acquirer configured to acquire battery information including an SOC of an on-board battery of an individual vehicle constituting the electric vehicle fleet; a participant configurator configured to set a plurality of vehicles satisfying a predetermined condition from among the electric vehicle fleet as charge participants; a priority configurator configured to set a priority order corresponding to an order of charge from the power grid for a plurality of the charge participants based on the SOC of the on-board battery; a charge and discharge controller configured to select at least one of a plurality of the charge participants in descending order of the priority order and to cause the selected vehicle to charge from the power grid when a charge request is generated by the power grid; and a discharge depth calculator configured to calculate a depth of discharge of the on-board battery based on the battery information. The charge and discharge controller terminates charge of a vehicle during charge when the depth of discharge of the on-board battery reaches a predetermined threshold value, and starts charge of a vehicle in next priority order.
[0014] (7) According to the above aspect, the priority configurator sets the priority order for a plurality of the charge participants in ascending order of the SOC of the on-board battery.
[0015] (8) According to the above aspect, the battery information includes an SOH corresponding to health of the on-board battery, and the priority configurator sets the priority order for a plurality of the charge participants based on the SOC and the SOH of the on-board battery.
[0016] (9) According to the above aspect, the participant configurator sets a vehicle with the SOC of the on-board battery lower than a charge allowable threshold as the charge participant among a plurality of vehicles constituting the electric vehicle fleet, and the charge and discharge controller terminates charge of a vehicle during charge when the depth of discharge of the on-board battery reaches the threshold value, even if the SOC of the on-board battery is lower than the charge allowable threshold.
[0017] (10) According to the above aspect, the participant configurator sets a vehicle that does not elapse a predetermined charge / discharge waiting period after charging or discharging the on-board battery until the depth of discharge reaches the threshold value as a charge non-participant.Effects of the Invention
[0018] (1) In the present invention, the participant configurator sets vehicles satisfying a predetermined condition from among the electric vehicle fleet as discharge participants, the priority configurator sets the priority order corresponding to the order of discharge to the power grid for the discharge participants based on the SOC of the individual on-board batteries, and the charge and discharge controller selects at least one of the discharge participants in descending order of the priority order and causes the selected vehicle to discharge to the power grid when the discharge request is generated by the power grid. According to the present invention, when the discharge request is generated by the power grid, the charge and discharge controller causes the vehicles to discharge in the order determined based on the SOC of each discharge participant, thereby preventing the vehicles from falling short of capacity while responding to the discharge request. Also, in the present invention, the discharge depth calculator calculates the depth of discharge of individual on-board batteries based on the battery information, and when the depth of discharge of the vehicle during discharge reaches the predetermined threshold, the charge and discharge controller terminates discharge of the vehicle and starts discharge of the vehicle in next priority order. Thus, according to the present invention, even in the case of a prolonged discharge request from the power grid, the electric energy exceeding the threshold value of the depth of discharge is not discharged from individual vehicles at once. Therefore, according to the present invention, the degradation of the on-board batteries can be suppressed while responding to the demand from the power grid, thereby contributing to the improvement of energy efficiency.
[0019] (2) In the present invention, the priority configurator sets the priority order for the discharge participants in descending order of the SOC of the individual on-board batteries. Thus, according to the present invention, when the discharge request is generated by the power grid, the discharge participants with larger SOC can be discharged at first, thereby preventing the vehicles from falling short of capacity while responding to the discharge request.
[0020] (3) In the present invention, the priority configurator sets the priority order for the discharge participants based on the SOC and the SOH of the on-board batteries. Thus, according to the present invention, when the discharge request is generated by the power grid, the on-board batteries can be discharged in the order determined based on the SOC and the SOH of each discharge participant, thereby reducing the degradation of the on-board batteries.
[0021] (4) In the present invention, the participant configurator sets a vehicle whose SOC of the on-board battery is higher than the discharge allowable threshold as the discharge participant. The charge and discharge controller terminates discharge of the vehicle during discharge when the depth of discharge reaches the predetermined threshold, even if the SOC at the time is higher than the discharge allowable threshold. In other words, in the present invention, when the depth of discharge reaches the threshold value, the discharge is terminated and the vehicle is switched to a vehicle with the next priority order, even if the on-board battery capacity is still available at that time. Thereby, the degradation of the on-board battery can be more reliably suppressed.
[0022] (5) In the present invention, the participant configurator sets a vehicle that does not elapse the predetermined charge / discharge waiting period after charging or discharging until the depth of discharge reaches the predetermined threshold value as a discharge non-participant. Thus, according to the present invention, it is possible to prevent the electric energy exceeding the threshold value of the depth of discharge to be discharged from the on-board battery within a short period of time, and thus to suppress the degradation of individual on-board batteries.
[0023] (6) In the present invention, the participant configurator sets vehicles satisfying a predetermined condition from among the electric vehicle fleet as charge participants, the priority configurator sets the priority order corresponding to the order of charge from the power grid for the charge participants based on the SOC of the individual on-board batteries, and the charge and discharge controller selects at least one of the charge participants in descending order of the priority order and causes the selected vehicle to charge from the power grid when the charge request is generated by the power grid. According to the present invention, when the charge request is generated by the power grid, the charge and discharge controller causes the vehicles to charge in the order determined based on the SOC of each charge participant, thereby preventing the vehicles from falling short of capacity while responding to the charge request. Also, in the present invention, the discharge depth calculator calculates the depth of discharge of individual on-board batteries based on the battery information, and when the depth of discharge of the vehicle during charge reaches the predetermined threshold, the charge and discharge controller terminates charge of the vehicle and starts charge of the vehicle in next priority order. Thus, according to the present invention, even in the case of a prolonged charge request from the power grid, the electric energy exceeding the threshold value of the depth of charge is not charged to individual vehicles at once. Therefore, according to the present invention, the degradation of the on-board batteries can be suppressed while responding to the demand from the power grid, thereby contributing to the improvement of energy efficiency.
[0024] (7) In the present invention, the priority configurator sets the priority order for the charge participants in ascending order of the SOC of the individual on-board batteries. Thus, according to the present invention, when the charge request is generated by the power grid, the charge participants with smaller SOC can be charged at first, thereby preventing the vehicles from falling short of capacity while responding to the charge request.
[0025] (8) In the present invention, the priority configurator sets the priority order for the charge participants based on the SOC and the SOH of the on-board batteries. Thus, according to the present invention, when the charge request is generated by the power grid, the on-board batteries can be charged in the order determined based on the SOC and the SOH of each charge participant, thereby reducing the degradation of the on-board batteries.
[0026] (9) In the present invention, the participant configurator sets a vehicle whose SOC of the on-board battery is lower than the charge allowable threshold as the charge participant. The charge and discharge controller terminates charge of the vehicle during charge when the depth of discharge reaches the predetermined threshold, even if the SOC at the time is lower than the charge allowable threshold. In other words, in the present invention, when the depth of discharge reaches the threshold value, the charge is terminated and the vehicle is switched to a vehicle with the next priority order, even if the on-board battery capacity is still available at the time. Thereby, the degradation of the on-board battery can be more reliably suppressed.
[0027] (10) In the present invention, the participant configurator sets a vehicle that does not elapse the predetermined charge / discharge waiting period after charging or discharging until the depth of discharge reaches the predetermined threshold value as a charge non-participant. Thus, according to the present invention, it is possible to prevent the electric energy exceeding the threshold value of the depth of discharge to be charged to the on-board battery within a short period of time, and thus to suppress the degradation of individual on-board batterie.
[0028] FIG. 1 is a schematic diagram illustrating a configuration of a charge / discharge management system and a part of a management area of the charge / discharge management system.FIG. 2 is a block diagram illustrating a configuration of the charge / discharge management system.FIG. 3A is a first example of a change in SOC caused by discharge and charge.FIG. 3B is a second example of a change in SOC caused by discharge and charge.FIG. 3C is a third example of a change in SOC caused by discharge and charge.FIG. 4 is a flowchart illustrating a specific procedure of discharge participants setting process.FIG. 5 is a flowchart illustrating a specific procedure of charge participants setting process.FIG. 6 is a flowchart illustrating a specific procedure of discharge control process.FIG. 7 is a flowchart illustrating a specific procedure of charge control process.FIG. 8 is a diagram illustrating a management procedure by the charge / discharge management system (first example).FIG. 9 is a diagram illustrating a management procedure by the charge / discharge management system (second example).
[0029] A charge / discharge management system according to an embodiment of the present invention will be described with reference to the drawings.
[0030] FIG. 1 is a schematic diagram illustrating a configuration of a charge / discharge management system 1 and a part of a management area A of the charge / discharge management system 1. Within the management area A, there are a plurality of electric vehicles V1, V2, V3, V4, V5, V6, … connected to a power grid G via a plurality of charge / discharge stations Sa, Sb, …. The charge / discharge management system 1 is a computer that manages these electric vehicles V1, V2, … and on-board batteries equipped in each of these plurality of electric vehicles V1, V2, … as management targets, and manages the charge and discharge of these management targets. In the present invention, the electric vehicles V1, V2, … to be managed by the charge / discharge management system 1 are also referred to collectively as “electric vehicle fleet”.
[0031] An electrical utility provider supplies power generated by operating a power plant P to a plurality of consumers C1, C2, C3, … and a plurality of charge / discharge stations Sa, Sb, … via the power grid G.
[0032] A manager of the charge / discharge management system 1, also called an aggregator, uses the charge / discharge management system 1 to manage charge and discharge of the electric vehicle fleet so that a balance is maintained between power generation and power consumption in the power grid G.
[0033] The first charge / discharge station Sa is equipped with a plurality of charge / discharge facilities Fa1, Fa2, Fa3, …, which are communicatively connected to the charge / discharge management system 1 via a network. Electric vehicles V1 and V2 are connected to the charge / discharge facilities Fa1 and Fa2, respectively. The charge / discharge facilities Fa1 and Fa2 connect the on-board batteries of the electric vehicles V1 and V2 to the power grid G, and in response to command signals transmitted from the charge / discharge management system 1, cause the on-board batteries of the electric vehicles V1 and V2 to charge and discharge.
[0034] The second charge / discharge station Sb is equipped with a plurality of charge / discharge facilities Fb1, Fb2, Fb3, Fb4, Fb5, …, which are communicatively connected to the charge / discharge management system 1 via the network. Electric vehicles V3, V4, V5, and V6 are connected to the charge / discharge facilities Fb1, Fb3, Fb4, and Fb5 respectively. The charge / discharge facilities Fb1, Fb3, Fb4, and Fb5 connect the on-board batteries of the electric vehicles V3, V4, V5, and V6 to the power grid G, and in response to command signals transmitted from the charge / discharge management system 1, cause the on-board batteries of the electric vehicles V3, V4, V5, and V6 to charge and discharge. These charge / discharge stations Sa, Sb, … are installed in homes, offices, and commercial facilities, for example.
[0035] The charge / discharge management system 1 includes one or more computers communicatively connected to a plurality of the charge / discharge facilities Fa1, …, Fb1, …, a plurality of the electric vehicles V1, V2, … connected to these charge / discharge facilities Fa1, …, Fb1, …, and portable information processing terminals owned by the users of each electric vehicle V1, V2, …, etc., via base stations. More specifically, the charge / discharge management system 1 includes a server connected to a plurality of the charge / discharge facilities Fa1, …, Fb1, …, etc. via the base stations, a network core, and the Internet, and an edge server connected to a plurality of the charge / discharge facilities Fa1, …, Fb1, …, etc. via the base stations and a multi-access edge computing (MEC) core.
[0036] FIG. 2 is a block diagram illustrating a configuration of the charge / discharge management system 1. The charge / discharge management system 1 includes: a grid demand acquirer 10; a battery information acquirer 11; a vehicle information acquirer 12; a classifier 13; a V2G participant configurator 14; a priority configurator 15; a discharge depth calculator 16; and a charge / discharge controller 17. Each function of the blocks 10 to 17 described below is realized by the charge / discharge management system 1, which is a computer, by executing a computer program installed in a storage medium not shown.
[0037] The grid demand acquirer 10 acquires a grid demand [kW] in the power gird G by means of a management device not shown in FIG. 2. The grid demand corresponds to the power demand in the power grid G. Thus, the grid demand is positive when power consumption is excessive relative to power generation in the power grid G. In other words, the grid demand is positive when a discharge request is generated by the power grid G to the electric vehicle fleet. Also, the grid demand is negative when power generation is excessive relative to power consumption in the power grid G. In other words, the grid demand is negative when a charge request is generated by the power grid G to the electric vehicle fleet. As shown in FIG. 2 schematically, the grid demand can be positive or negative, depending on various factors such as hours of day, environment, power plant conditions, and consumer activity.
[0038] The battery information acquirer 11 acquires battery information concerning the on-board batteries of individual electric vehicles constituting the electric vehicle fleet by using communications to the charge / discharge facilities and to the individual electric vehicles. Here, the battery information acquired by the battery information acquirer 11 includes, for example, an SOC[%] expressed as a percentage of the remaining capacity[kWh] of the on-board battery, an SOH[%] expressed as a percentage of the health of the on-board battery (e.g., capacity maintenance rate), and a temperature of the on-board battery.
[0039] The vehicle information acquirer 12 acquires vehicle information concerning the individual electric vehicles constituting the electric vehicle fleet by using communications to the charge / discharge facilities and to the individual electric vehicles. Here, the vehicle information acquired by the vehicle information acquirer 12 includes, for example, a recent past driving history and a recent future use schedule.
[0040] The classifier 13 classifies a plurality of vehicles constituting the electric vehicle fleet into one of Group 1 to 3 based on the battery information acquired by the battery information acquirer 11. In general, in a high SOC state where the SOC is maintained higher than a predetermined optimal SOC upper limit[%] (e.g., about 70[%]) or in a low SOC state where the SOC is maintained below an optimal SOC lower limit[%] (e.g., about 30[%]) defined lower than the optimal SOC upper limit, the degradation tends to progress faster than in a state where the SOC is maintained within the optimal SOC lower limit to the optimal SOC upper limit (hereinafter referred to as “optimal SOC band”).
[0041] The classifier 13 classifies the electric vehicle into Group 1 when the SOC of the on-board battery is higher than the optimal SOC upper limit, i.e., when the on-board battery is in the high SOC state. The classifier 13 classifies the electric vehicle into Group 2 when the SOC of the on-board battery is below the optimal SOC lower limit, i.e., when the on-board battery is in the low SOC state. Also, the classifier 13 classifies the electric vehicle into Group 3 when the SOC of the on-board battery is within the optimal SOC band, i.e., when the on-board battery is in a state that enables the slowest degradation of the on-board battery.
[0042] The discharge depth calculator 16 calculates a depth of discharge (hereinafter referred to as “DOD”), which indicates the depth of discharge or charge of the on-board battery, based on the battery information acquired by the battery information acquirer 11. The discharge depth calculator 16 calculates the DOD[%] as the variation width of the SOC of the on-board battery due to discharge or charge. More specifically, the discharge depth calculator 16 calculates the difference between the maximum and minimum values of the SOC during the discharge or charge period as the DOD. Here, the discharge depth calculator 16 resets the DOD to 0[%] when the on-board battery has not been charged or discharged for a predetermined charge / discharge waiting period.
[0043] FIG. 3A is a first example of a change in SOC caused by discharge or charge. In the example on the left side of FIG. 3A, the SOC decreases from 70[%] to 30[%] by discharging from the on-board battery. Therefore, in the example on the left side of FIG. 3A, the DOD is 40[%]. In the example on the right side of FIG. 3B, the SOC increases from 30[%] to 70[%] by charging the on-board battery. Therefore, in the example on the right side of FIG. 3A, the DOD is 40[%].
[0044] FIG. 3B is a second example of a change in SOC caused by discharge or charge. The left side of FIG. 3B shows a case where the on-board battery is discharged over the period from time t1 to t2, then the on-board battery waits without charging or discharging until time t3, and then the on-board battery is discharged again over the period from time t3 to t4. The right side of FIG. 3B shows a case where the on-board battery is charged over the period from time t11 to t12, then the on-board battery waits without charging or discharging until time t13, and then the on-board battery is charged again over the period from time 13 to 14. Note that in the examples shown in FIG. 3B, the periods when charging and discharging are not performed (periods t2 to t3 and t12 to t13) are shorter than the charge / discharge waiting period described above.
[0045] In the example on the left side of FIG. 3B, discharging from the on-board battery causes the SOC to decrease from 70[%] to 50[%], and then the SOC decreases again from 50[%] to 30[%]. Therefore, in the example on the left side of FIG. 3B, the DOD is 20[%] during the period t2 to t3. The period t2 to t3 is shorter than the charge / discharge waiting period as described above. Therefore, in the example on the left side of FIG. 3B, the DOD at time t4 is 40[%] (= 20[%] + 20[%]).
[0046] In the example on the right side of FIG. 3B, charging to the on-board battery causes the SOC to increase from 30[%] to 50[%], and then the SOC increase again from 50[%] to 70[%]. Therefore, in the example on the right side of FIG. 3B, the DOD is 20[%] during the period t12 to t13. The period t12 to t13 is shorter than the charge / discharge waiting period as described above. Therefore, in the example on the right side of FIG. 3B, the DOD at time t14 is 40[%] (= 20[%] + 20[%]).
[0047] FIG. 3C is a third example of a change in SOC caused by discharge or charge. Note that in contrast to the examples in FIG. 3B, FIG. 3C shows a case in which the periods when charging and discharging are not performed (period t2 to t3 and t12 to t13) are longer than the charge / discharge waiting period described above.
[0048] Thus, in the example on the left side of FIG. 3C, the DOD at time t2 is 20[%]. However, in the example on the left side of FIG. 3C, the DOD is reset to 0[%] when the charge / discharge waiting period elapses from time t2. Therefore, in the example on the left side of FIG. 3C, the DOD is 20[%] at time t4.
[0049] In the example on the right side of FIG. 3C, the DOD at time t12 is 20[%]. However, in the example on the right side of FIG. 3C, the DOD is reset to 0[%] when the charge / discharge waiting period elapses from time t12. Therefore, in the example on the right side of FIG. 3C, the DOD is 20[%] at time t14.
[0050] Returning to FIG. 2, when the grid demand is positive, i.e., when a discharge request is generated from the power grid G to the electric vehicle fleet, the V2G participant configurator 14 sets a plurality of the electric vehicles in the electric vehicle fleet as discharge participants based on the grid demand, the battery information, the vehicle information, and the classification results by the classifier 13. Here, the discharge participants are the electric vehicles that are scheduled to participate in discharging to the power grid G. More specifically, when the grid demand is positive, the V2G participant configurator 14 sets a plurality of the electric vehicles satisfying predetermined conditions (e.g., vehicles belonging to Group 1 whose on-board batteries are over-charged) from among the electric vehicle fleet as the discharge participants.
[0051] Also, when the grid demand is negative, i.e., when a charge request is generated from the power grid G to the electric vehicle fleet, the V2G participant configurator 14 sets a plurality of the electric vehicles in the electric vehicle fleet as charge participants based on the grid demand, the battery information, the vehicle information, and the classification results by the classifier 13. Here, the charge participants are the electric vehicles that are scheduled to participate in charging from the power grid G. More specifically, when the grid demand is negative, the V2G participant configurator 14 sets a plurality of the electric vehicles satisfying predetermined conditions (e.g., vehicles belonging to Group 2 whose on-board batteries are over-discharged) from among the electric vehicle fleet as the charge participants.
[0052] FIG. 4 is a flowchart illustrating a specific procedure of discharge participants setting process. This discharge participants setting process is repeatedly executed by the V2G participant configurator 14 in a predetermined cycle while the grid demand is positive.
[0053] First, in Step ST1, the V2G participant configurator 14 sets discharge participants and non-participants from Group 1, and proceeds to Step ST2. More specifically, the V2G participant configurator 14 sets the electric vehicles that satisfy all of the first to third discharge allowable conditions described below among a plurality of the electric vehicles belonging to Group 1 (i.e., electric vehicles whose SOC is higher than the optimal SOC upper limit) as discharge participants, and sets the other electric vehicles as discharge non-participants.
[0054] As the first discharge allowable condition, the V2G participant configurator 14 sets the electric vehicles whose SOH of the on-board battery is above a predetermined protection threshold (e.g., 60[%]) as the discharge participants. By imposing such first discharge allowable condition, the V2G participant configurator 14 can suppress the discharge of the on-board battery, which is already degraded, to prevent further degradation of this on-board battery.
[0055] As the second discharge allowable condition, the V2G participant configurator 14 sets the electric vehicles whose DOD of the on-board battery is less than a predetermined DOD threshold value [%] (hereinafter also referred to as “threshold DODth”) as discharge participants. As described above, the discharge depth calculator 16 resets the DOD to 0[%] when the vehicle waits over the charge / discharge waiting period without charging and discharging. Therefore, by imposing such second discharge allowable condition, the V2G participant configurator 14 can set the electric vehicle which has not elapsed the charge / discharge waiting period after charging or discharging until the DOD of the on-board battery reaches the threshold DODth as the discharge non-participant. In other words, by imposing such second discharge allowable condition, the V2G participant configurator 14 can set the electric vehicle which has elapsed the charge / discharge waiting period after completing the charge or discharge and the SOC of the on-board battery is higher than the optimal SOC upper limit as the discharge participant. Therefore, by imposing such second discharge allowable condition, the V2G participant configurator 14 can prevent the electric energy exceeding the threshold DODth being discharged from the on-board battery in a short period of time, thereby preventing the degradation of the on-board battery.
[0056] As the third discharge allowable condition, the V2G participant configurator 14 sets the electric vehicle which is not scheduled to be used until a predetermined time in the future as the discharge participant. By imposing such third discharge allowable condition, the V2G participant configurator 14 can prevent the user from being unable to use the electric vehicle according to use schedule.
[0057] Next, in Step ST2, the V2G participant configurator 14 calculates total electric energy [kWh] that can be discharged from the discharge participants belonging to Group 1 to the power grid G, and proceeds to Step ST3. More specifically, the V2G participant configurator 14 calculates the total electric energy based on the number of discharge participants belonging to Group 1, the SOC, the SOH, and the DOD of each discharge participant, etc.
[0058] Next, in Step ST3, the V2G participant configurator 14 determines whether the total electric energy calculated in Step ST2 is greater than required electric energy[kWh] from the power grid G. The V2G participant configurator 14 calculates the required electric energy from the power grid G based on, for example, the grid demand and hours of day. When the determination result of Step ST3 is YES, i.e., only the discharge participants belonging to Group 1 can respond to the demand from the power grid G, the V2G participant configurator 14 proceeds to Step ST4. When the determination result of Step ST3 is NO, i.e., only the discharge participants belonging to Group 1 cannot respond to the demand from the power grid G, the V2G participant configurator 14 proceeds to Step ST5.
[0059] In Step ST4, the V2G participant configurator 14 sets all electric vehicles belonging to Groups 2 and 3 as the discharge non-participants, and ends the process illustrated in FIG. 4.
[0060] In Step ST5, the V2G participant configurator 14 sets the discharge participants and non-participants from Group 3, and proceeds to Step ST6. More specifically, the V2G participant configurator 14 sets the electric vehicles that satisfy all of the first to third discharge allowable conditions described above among a plurality of the electric vehicles belonging to Group 3 (i.e., electric vehicles whose SOC is within the optimal SOC band) as the discharge participants, and sets the other electric vehicles as the discharge non-participants.
[0061] In Step ST6, the V2G participant configurator 14 sets all electric vehicles belonging to Group 2 as the discharge non-participants, and ends the process illustrated in FIG. 4.
[0062] As described above, the V2G participant configurator 14 basically sets the electric vehicles belonging to Group 1 (i.e., the electric vehicles whose SOC is higher than the optimal SOC upper limit) as the discharge participants when the grid demand is positive. In addition, the V2G participant configurator 14 sets the electric vehicles belonging to Groups 1 and 3 (i.e., electric vehicles whose SOC is higher than the optimal SOC lower limit) as the discharge participants when the demand from the power grid G cannot be responded to only by the discharge participants belonging to Group 1. In other words, the V2G participant configurator 14 sets vehicles whose SOC of the on-board battery is higher than a predetermined discharge allowable threshold (when enough in Group 1, discharge allowable threshold = optimal SOC upper limit; when not enough in Group 1, discharge allowable threshold = optimal SOC lower limit) from among a plurality of the electric vehicles constituting the electric vehicle fleet as the discharge participants. The V2G participant configurator 14 does not set electric vehicles belonging to Group 2 as the discharge participants.
[0063] FIG. 5 is a flowchart illustrating a specific procedure of charge participants setting process. This charge participants setting process is repeatedly executed by the V2G participant configurator 14 in the predetermined cycle while the grid demand is negative.
[0064] First, in Step ST11, the V2G participant configurator 14 sets charge participants and non-participants from Group 1, and proceeds to Step ST12. More specifically, the V2G participant configurator 14 sets the electric vehicles that satisfy all of the first to third charge allowable conditions described below among a plurality of the electric vehicles belonging to Group 2 (i.e., electric vehicles whose SOC is lower than the optimal SOC lower limit) as charge participants, and sets the other electric vehicles as charge non-participants.
[0065] As the first charge allowable condition, the V2G participant configurator 14 sets the electric vehicles whose SOH of the on-board battery is above the protection threshold (e.g., 60[%]) as the charge participants. By imposing such first charge allowable condition, the V2G participant configurator 14 can suppress the charge of the on-board battery, which is already degraded, to prevent further degradation of this on-board battery.
[0066] As the second charge allowable condition, the V2G participant configurator 14 sets the electric vehicles whose DOD of the on-board battery is less than the threshold DODth as charge participants. As described above, the discharge depth calculator 16 resets the DOD to 0% when the vehicle waits over the charge / discharge waiting period without charging and discharging. Therefore, by imposing such second charge allowable condition, the V2G participant configurator 14 can set the electric vehicle which has not elapsed the charge / discharge waiting period after charging or discharging until the DOD of the on-board battery reaches the threshold DODth as the charge non-participant. In other words, by imposing such second charge allowable condition, the V2G participant configurator 14 can set the electric vehicle which has elapsed the charge / discharge waiting period after completing the charge or discharge and the SOC of the on-board battery is lower than the optimal SOC lower limit as the charge participant. Therefore, by imposing such second charge allowable condition, the V2G participant configurator 14 can prevent the electric energy exceeding the threshold DODth being charged to the on-board battery in a short period of time, thereby preventing the degradation of the on-board battery.
[0067] As the third charge allowable condition, the V2G participant configurator 14 sets the electric vehicle which is not scheduled to be used until a predetermined time in the future as the charge participant. By imposing such third charge allowable condition, the V2G participant configurator 14 can prevent the user from being unable to use the electric vehicle according to use schedule.
[0068] Next, in Step ST12, the V2G participant configurator 14 calculates total electric energy [kWh] that can be charged to the charge participants belonging to Group 2 from the power grid G, and proceeds to Step ST13. More specifically, the V2G participant configurator 14 calculates the total electric energy based on the number of charge participants belonging to Group 2, the SOC, the SOH, and the DOD of each charge participant, etc.
[0069] Next, in Step ST13, the V2G participant configurator 14 determines whether the total electric energy calculated in Step ST12 is greater than required electric energy [kWh] from the power grid G. The V2G participant configurator 14 calculates the required electric energy from the power grid G based on, for example, the grid demand and hours of day. When the determination result of Step ST13 is YES, i.e., only the charge participants belonging to Group 2 can respond to the demand from the power grid G, the V2G participant configurator 14 proceeds to Step ST14. When the determination result of Step ST13 is NO, i.e., only the charge participants belonging to Group 2 cannot respond to the demand from the power grid G, the V2G participant configurator 14 proceeds to Step ST15.
[0070] In Step ST14, the V2G participant configurator 14 sets all electric vehicles belonging to Groups 1 and 3 as the charge non-participants, and ends the process illustrated in FIG. 5.
[0071] In Step ST15, the V2G participant configurator 14 sets the charge participants and non-participants from Group 3, and proceeds to Step ST16. More specifically, the V2G participant configurator 14 sets the electric vehicles that satisfy all of the first to third charge allowable conditions described above among a plurality of the electric vehicles belonging to Group 3 (i.e., electric vehicles whose SOC is within the optimal SOC band) as the charge participants, and sets the other electric vehicles as the charge non-participants.
[0072] In Step ST16, the V2G participant configurator 14 sets all electric vehicles belonging to Group 1 as the charge non-participants, and ends the process illustrated in FIG. 5.
[0073] As described above, the V2G participant configurator 14 basically sets the electric vehicles belonging to Group 2 (i.e., the electric vehicles whose SOC is lower than the optimal SOC lower limit) as the charge participants when the grid demand is negative. In addition, the V2G participant configurator 14 sets the electric vehicles belonging to Groups 2 and 3 (i.e., electric vehicles whose SOC is lower than the optimal SOC upper limit) as the charge participants when the demand from the power grid G cannot be responded to only by the charge participants belonging to Group 2. In other words, the V2G participant configurator 14 sets vehicles whose SOC of the on-board battery is lower than a predetermined charge allowable threshold (when enough in Group 2, charge allowable threshold = optimal SOC lower limit; when not enough in Group 2, charge allowable threshold = optimal SOC upper limit) from among a plurality of the electric vehicles constituting the electric vehicle fleet as the charge participants. The V2G participant configurator 14 does not set electric vehicles belonging to Group 1 as the charge participants.
[0074] Returning to FIG. 2, the priority configurator 15 sets a discharge priority order and a charge priority order for a plurality of the discharge participants and a plurality of the charge participants configured by the V2G participant configurator 14 as described above. The discharge priority order corresponds to an order to start discharging to the power grid G for a plurality of the discharge participants. The charge priority order corresponds to an order to start charging from the power grid G for a plurality of the charge participants. In other words, the charge / discharge controller 17, described below, starts discharging to the power grid G in the order of the discharge participants with the highest discharge priority order. Also, the charge / discharge controller 17 starts charging from power grid G in the order of the charge participants with the highest charge priority order.
[0075] The priority configurator 15 sets the discharge priority order for the discharge participants based on the SOC and the SOH of the individual on-board batteries. More specifically, the priority configurator 15 basically sets the discharge priorities in descending order of the SOC of the individual on-board batteries. Therefore, the discharge priority order for a plurality of the discharge participants is basically set higher as the SOC increases. In case where the priority cannot be set based only on the SOC of the on-board batteries, i.e., where the SOC of two or more on-board batteries overlap, the priority configurator 15 sets the discharge priority order in descending order of the SOH of the individual on-board batteries. Therefore, the discharge priority order for a plurality of the discharge participants with overlapping SOC is set higher as the SOH increases.
[0076] The priority configurator 15 sets the charge priority order for the charge participants based on the SOC and the SOH of the individual on-board batteries. More specifically, the priority configurator 15 basically sets the charge priorities in ascending order of the SOC of the individual on-board batteries. Therefore, the charge priority order for a plurality of the charge participants is basically set higher as the SOC decreases. In case where the priority cannot be set based only on the SOC of the on-board batteries, i.e., where the SOC of two or more on-board batteries overlap, the priority configurator 15 sets the charge priority order in descending order of the SOH of the individual on-board batteries. Therefore, the charge priority order for a plurality of the charge participants with overlapping SOC is set higher as the SOH increases.
[0077] The charge / discharge controller 17 controls charging or discharging between a plurality of the discharge or charge participants selected from the electric vehicle fleet and the power grid G by remotely operating the charge / discharge facilities Fa1, …, Fb1, …, via communication. More specifically, the charge / discharge controller 17 controls the discharge from a plurality of the discharge participants to the power grid G or the charge to a plurality of the charge participants from the power grid G by remotely operating the charge / discharge facilities Fa1, …, Fb1, … based on the grid demand acquired by the grid demand acquirer 10.
[0078] The charge / discharge controller 17 selects at least one of a plurality of the discharge participants configured by the V2G participant configurator 14 in descending discharge priority order when the grid demand is positive (i.e., when the discharge requirement is generated by the power grid G), and causes the selected vehicle to discharge to the power grid G. Furthermore, when the DOD of the on-board battery of the vehicle during discharge reaches the predetermined threshold DODth, the charge / discharge controller 17 terminates the discharge of this vehicle and starts discharge of the discharge participant with the next highest discharge priority order.
[0079] The charge / discharge controller 17 selects at least one of a plurality of the charge participants configured by the V2G participant configurator 14 in descending charge priority order when the grid demand is negative (i.e., when the charge requirement is generated by the power grid G), and causes the selected vehicle to charge from the power grid G. Furthermore, when the DOD of the on-board battery of the vehicle during charge reaches the threshold DODth, the charge / discharge controller 17 terminates the charge of this vehicle and starts charge of the charge participant with the next highest charge priority order. Here, the threshold DODth for the DOD of the on-board battery is set to a value less than 20[%], for example, preferably less than 10[%], to minimize degradation to the on-board battery due to discharge or charge with the power grid G.
[0080] FIG. 6 is a flowchart illustrating a specific procedure of discharge control process. This discharge control process is repeatedly executed by the charge / discharge controller 17 in a predetermined cycle while the grid demand is positive.
[0081] First, in Step ST21, the charge / discharge controller 17 determines whether the grid demand is positive or not. When the determination result of Step ST21 is YES, the charge / discharge controller 17 proceeds to Step ST22, and when the result of Step ST21 is NO, ends the process in FIG. 6.
[0082] Next, in Step ST22, the charge / discharge controller 17 sets a simultaneous connection number Ncd (“Ncd” is an integer greater than or equal to 1) based on the grid demand, and proceeds to Step ST23. Here, the simultaneous connection number Ncd corresponds to the number of vehicles to be simultaneously discharged to the power grid G. The charge / discharge controller 17 sets the value of the simultaneous connection number Ncd to an integer value between 1 and the total number of the discharge participants. The charge / discharge controller 17 may set the value of the simultaneous connection number Ncd based on the grid demand, as explained later with reference to FIG. 8, or may set the value of the simultaneous connection number Ncd based on configuration of the discharge participants, as explained later with reference to FIG. 9. The charge / discharge controller 17 preferably sets the value of the simultaneous connection number Ncd to larger values as the grid demand increases.
[0083] Next, in Step ST23, the charge / discharge controller 17 selects Ncd vehicles from a plurality of the discharge participants in descending discharge priority order, and proceeds to Step ST24.
[0084] Next, in Step ST24, the charge / discharge controller 17 determines whether the grid demand is positive or not. When the result of the determination in Step ST24 is YES, the charge / discharge controller 17 proceeds to Step ST25, and when the result is NO, ends the process in FIG. 6.
[0085] Next, in Step ST25, the charge / discharge controller 17 causes the Ncd vehicles selected in Step ST23 to discharge to the power grid G, and proceeds to Step ST26. Here, When discharging from two or more vehicles to the power grid G, the charge / discharge controller 17 preferably divides the grid demand by the simultaneous connection number Ncd so that the sum of the power discharged from the individual vehicles is equal to the grid demand. Moreover, when discharging from two or more vehicles to the power grid G, the charge / discharge controller 17 preferably adjusts the power discharged from the individual vehicles so that the times at which the DOD of the individual on-board batteries reaches the threshold DODth are approximately the same time.
[0086] Next, in Step ST26, the charge / discharge controller 17 determines whether the DOD of the on-board batteris of the Ncd vehicles during discharge is greater than or equal to the threshold DODth. When the result of the determination in Step ST26 is YES, the charge / discharge controller 17 proceeds to Step ST27, and when the result is NO, returns to Step ST24.
[0087] In Step ST27, the charge / discharge controller 17 terminates the discharge from the Ncd vehicles selected in Step ST23 to the power grid G, and returns to Step ST21.
[0088] Thus, when the DOD of the on-board batteries of the Ncd vehicles during discharge reaches the threshold DODth, the charge / discharge controller 17 terminates the discharge even if the SOC of the on-board batteries is higher than the discharge allowable threshold (when enough in Group 1, discharge allowable threshold = optimal SOC upper limit; when not enough in Group 1, discharge allowable threshold = optimal SOC lower limit) at that time. As explained above, in the discharge participants setting process (see FIG. 4), the V2G participant configurator 14 again sets the electric vehicle as the discharge participant after the charge / discharge waiting period has elapsed after the completion of charging or discharging. Therefore, the vehicle which has completed discharging in Step ST27 may discharge agein after at leaset the charge / discharge waiting period has elapsed.
[0089] Thus, while the grid demand is positive, the charge / discharge controller 17 perfoms repeatedly Step ST23, in which it selects Ncd vehicles from among a plurality of the discharge participants in descending discharge priority order according to the magnitude of the grid demand, Step ST25, in which it discharges the power corresponding to the grid demand from the selected Ncd vehicles to the power grid G, and Step ST27, in which it terminates the discharge by the vehicles whose DOD reaches the threshold DODth, so that the power according to the grid demand is continuously supplied from the discharge participants to the power grid G.
[0090] FIG. 7 is a flowchart illustrating a specific procedure of charge control process. This charge control process is repeatedly executed by the charge / discharge controller 17 in a predetermined cycle while the grid demand is negative.
[0091] First, in Step ST31, the charge / discharge controller 17 determines whether the grid demand is negative or not. When the determination result of Step ST31 is YES, the charge / discharge controller 17 proceeds to Step ST32, and when the result of Step ST31 is NO, ends the process in FIG. 7.
[0092] Next, in Step ST32, the charge / discharge controller 17 sets a simultaneous connection number Ncc (“Ncc” is an integer greater than or equal to 1) based on the grid demand, and proceeds to Step ST33. Here, the simultaneous connection number Ncc corresponds to the number of vehicles to be simultaneously charged from the power grid G. The charge / discharge controller 17 sets the value of the simultaneous connection number Ncc to an integer value between 1 and the total number of the charge participants. More specifically, the charge / discharge controller 17 may set the value of the simultaneous connection number Ncc based on the grid demand or configuration of the charge participants, as in Step ST22 in FIG. 6. The charge / discharge controller 17 preferably sets the value of the simultaneous connection number Ncc to larger values as the grid demand increases toward negative side.
[0093] Next, in Step ST33, the charge / discharge controller 17 selects Ncc vehicles from a plurality of the charge participants in descending charge priority order, and proceeds to Step ST34.
[0094] Next, in Step ST34, the charge / discharge controller 17 determines whether the grid demand is negative or not. When the result of the determination in Step ST34 is YES, the charge / discharge controller 17 proceeds to Step ST35, and when the result is NO, ends the process in FIG. 7.
[0095] Next, in Step ST35, the charge / discharge controller 17 causes the Ncc vehicles selected in Step ST33 to charge from the power grid G, and proceeds to Step ST36. Here, When charging to two or more vehicles from the power grid G, the charge / discharge controller 17 preferably divides the grid demand by the simultaneous connection number Ncc so that the sum of the power charged to the individual vehicles is equal to the grid demand. Moreover, when charging to two or more vehicles from the power grid G, the charge / discharge controller 17 preferably adjusts the power charged to the individual vehicles so that the times at which the DOD of the individual on-board batteries reaches the threshold DODth are approximately the same time.
[0096] Next, in Step ST36, the charge / discharge controller 17 determines whether the DOD of the on-board batteris of the Ncc vehicles during charge is greater than or equal to the threshold DODth. When the result of the determination in Step ST36 is YES, the charge / discharge controller 17 proceeds to Step ST37, and when the result is NO, returns to Step ST34.
[0097] In Step ST37, the charge / discharge controller 17 terminates the charge to the Ncc vehicles selected in Step ST33 from the power grid G, and returns to Step ST31.
[0098] Thus, when the DOD of the on-board batteries of the Ncd vehicles during charge reaches the threshold DODth, the charge / discharge controller 17 terminates the charge even if the SOC of the on-board batteries is lower than the charge allowable threshold (when enough in Group 2, charge allowable threshold = optimal SOC lower limit; when not enough in Group 2, charge allowable threshold = optimal SOC upper limit) at that time. As explained above, in the charge participants setting process (see FIG. 5), the V2G participant configurator 14 again sets the electric vehicle as the charge participant after the charge / discharge waiting period has elapsed after the completion of charging or discharging. Therefore, the vehicle which has completed charging in Step ST37 may charge agein after at leaset the charge / discharge waiting period has elapsed.
[0099] Thus, while the grid demand is negative, the charge / discharge controller 17 perfoms repeatedly Step ST33, in which it selects Ncc vehicles from among a plurality of the charge participants in descending charge priority order according to the magnitude of the grid demand, Step ST35, in which it charges the power corresponding to the grid demand to the selected Ncd vehicles from the power grid G, and Step ST37, in which it terminates the charge by the vehicles whose DOD reaches the threshold DODth, so that the power according to the grid demand is continuously supplied from the power grid G to the charge participants.
[0100] Next, specific examples of management by the charge / discharge management system 1 described above will be explained with reference to FIG. 8 and 9.
[0101] FIGS. 8 and 9 are diagrams illustrating management procedures by the charge / discharge management system 1. More specifically, these FIGS. 8 and 9 illustrate only the top five discharge priority orders among a plurality of the electric vehicles set as the discharge participants. The SOH and SOC of vehicle 1 are 95[%] and 80[%], respectively. The SOH and SOC of vehicle 2 are 93[%] and 90[%], respectively. The SOH and SOC of vehicle 3 are 90[%] and 75[%], respectively. The SOH and SOC of vehicle 4 are 93[%] and 80[%], respectively. The SOH and SOC of vehicle 5 are 90[%] and 70[%], respectively. For easy understanding, vehicles 1 through 5 are assumed to be the same type of vehicle and their on-board batteries have a fresh capacity of 35[kWh]. Also, for easy understanding, the grid demand is assumed to be constant at 10[kW]. In the following, the threshold DODth is set at 10[%].
[0102] In these examples in FIGS. 8 and 9, the priority configurator 15 sets the discharge priority order for vehicles 1 through 5 configured as the discharge participants, basically in descending order of SOC. However, since the SOC of vehicle 1 and vehicle 4 are equal, the priority configurator 15 sets the discharge priority order in descending order of SOH. Thus, in these examples in FIGS. 8 and 9, the priority configurator 15 sets the priority order for vehicle 2 in 1st rank, vehicle 1 in 2nd rank, vehicle 4 in 3rd rank, vehicle 3 in 4th rank, and vehicle 5 in 5th rank.
[0103] FIG. 8 shows the case where the charge / discharge controller 17 sets the value of the simultaneous connection number Ncd to “1” based on the grid demand (see Step ST22 in FIG. 6).
[0104] In the first turn, the charge / discharge controller 17 selects the vehicle 2 with the highest discharge priority order among a plurality of the discharge participants and causes the vehicle 2 to discharge power to the power grid G. More specifically, the charge / discharge controller 17 causes the vehicle 2 to discharge 10[kW] of power to the power grid G for approximately 19.5[min] until the DOD reaches 10[%], in other word, until the SOC drops from 90[%] to 80[%]. The charge / discharge controller 17 terminates the discharge from the vehicle 2 when the DOD reaches 10[%], and proceeds to the next turn. Thus, in the first turn, the electric energy (3.26[kWh]) for 10[%] DOD is discharged from vehicle 2 to power grid G.
[0105] In the second turn, the charge / discharge controller 17 selects the vehicle 1 with the next discharge priority order following vehicle 2 from among a plurality of the discharge participants and causes this vehicle 1 to discharge power to the power grid G. More specifically, the charge / discharge controller 17 causes the vehicle 1 to discharge 10[kW] of power to the power grid G for approximately 20[min] until the DOD reaches 10[%], in other word, until the SOC drops from 80[%] to 70[%]. The charge / discharge controller 17 terminates the discharge from the vehicle 1 when the DOD reaches 10[%], and proceeds to the next turn. Thus, in the second turn, the electric energy (3.33[kWh]) for 10[%] DOD is discharged from vehicle 1 to power grid G.
[0106] In the third turn, the charge / discharge controller 17 selects the vehicle 4 with the next discharge priority order following vehicle 1 from among a plurality of the discharge participants and causes this vehicle 4 to discharge power to the power grid G. More specifically, the charge / discharge controller 17 causes the vehicle 4 to discharge 10[kW] of power to the power grid G for approximately 19.5[min] until the DOD reaches 10[%], in other word, until the SOC drops from 80[%] to 70[%]. The charge / discharge controller 17 terminates the discharge from the vehicle 4 when the DOD reaches 10[%], and proceeds to the next turn. Thus, in the third turn, the electric energy (3.26[kWh]) for 10[%] DOD is discharged from vehicle 4 to power grid G.
[0107] In the fourth turn, the charge / discharge controller 17 selects the vehicle 3 with the next discharge priority order following vehicle 4 from among a plurality of the discharge participants and causes this vehicle 3 to discharge power to the power grid G. More specifically, the charge / discharge controller 17 causes the vehicle 3 to discharge 10[kW] of power to the power grid G for approximately 18.9[min] until the DOD reaches 10[%], in other word, until the SOC drops from 75[%] to 65[%]. The charge / discharge controller 17 terminates the discharge from the vehicle 3 when the DOD reaches 10[%], and proceeds to the next turn. Thus, in the fourth turn, the electric energy (3.15[kWh]) for 10[%] DOD is discharged from vehicle 3 to power grid G.
[0108] In the fifth turn, the charge / discharge controller 17 selects the vehicle 5 with the next discharge priority order following vehicle 3 from among a plurality of the discharge participants and causes this vehicle 5 to discharge power to the power grid G. More specifically, the charge / discharge controller 17 causes the vehicle 5 to discharge 10[kW] of power to the power grid G for approximately 18.9[min] until the DOD reaches 10[%], in other word, until the SOC drops from 70[%] to 60[%]. The charge / discharge controller 17 terminates the discharge from the vehicle 5 when the DOD reaches 10[%], and proceeds to the next turn. Thus, in the fifth turn, the electric energy (3.15[kWh]) for 10[%] DOD is discharged from vehicle 5 to power grid G.
[0109] FIG. 9 shows the case where the charge / discharge controller 17 sets the value of the simultaneous connection number Ncd based on the configuration of the discharge participants (see Step ST22 in FIG. 6). More specifically, FIG. 9 shows the case where the charge / discharge controller 17 sets the total number of discharge participants with SOC higher than 80[%] as the simultaneous connection number Ncd in the first turn, the total number of discharge participants with SOC in the range of 70[%] to 80[%] as the simultaneous connection number Ncd in the second turn, and the total number of discharge participants with SOC in the range of 60[%] to 70[%] as the simultaneous connection number Ncd in the third turn. Thus, in the example in FIG. 9, the simultaneous connection number Ncd in the first turn is “1”, the simultaneous connection number Ncd in the second turn is “3”, and the simultaneous connection number Ncd in the third turn is “1”.
[0110] In the first turn, the charge / discharge controller 17 selects one vehicle from among a plurality of the discharge participants in descending discharge priority order. In other word, the charge / discharge controller 17 selects the vehicle 2 in the first turn and causes this vehicle 2 to discharge to the power grid G. More specifically, the charge / discharge controller 17 causes the vehicle 2 to discharge 10[kW] of power to the power grid G for approximately 19.5[min] until the DOD reaches 10[%], in other word, until the SOC drops from 90[%] to 80[%]. The charge / discharge controller 17 terminates the discharge from the vehicle 2 when the DOD reaches 10[%], and proceeds to the next turn. Thus, in the first turn, the electric energy (3.26[kWh]) for 10[%] DOD is discharged from vehicle 2 to power grid G.
[0111] In the second turn, the charge / discharge controller 17 selects three vehicles from among a plurality of the discharge participants in descending discharge priority order. In other word, the charge / discharge controller 17 selects the vehicles 1, 4, and 3 in the second turn and causes these vehicles 1, 4, and 3 to discharge to the power grid G. More specifically, the charge / discharge controller 17 causes these vehicles 1, 4, and 3 to discharge 10[kW] of total power to the power grid G until the DOD of these vehicles 1, 4, and 3 reache 10[%], in other word, until their respective SOCs drops to 70[%], 70[%], and 65[%]. In this case, the charge / discharge controller 17 divides the power discharged from these vehicles 1, 4, and 3 into the power grid G so that the DOD of these vehicles 1, 4, and 3 reaches 10[%] at approximately the same time. In this case, the power discharged from these vehicles 1, 4, and 3 is 3.42[kW], 3.35[kW], and 3.23[kW], respectively, and the discharge time is 58.4[min]. When the DOD of these vehicles 1, 4, and 3 reaches 10[%], the charge / discharge controller 17 terminates the discharge from these vehicles 1, 4, and 3, and proceeds to the next turn. Thus, in the second turn, the electric energy (3.33[kWh]) for 10[%] DOD is discharged from vehicle 1 to power grid G, the electric energy (3.26[kWh]) for 10[%] DOD is discharged from vehicle 4 to power grid G, and the electric energy (3.15[kWh]) for 10[%] DOD is discharged from vehicle 3 to power grid G,.
[0112] In the third turn, the charge / discharge controller 17 selects one vehicle from among a plurality of the discharge participants in descending discharge priority order. In other word, the charge / discharge controller 17 selects the vehicle 5 in the third turn, and causes this vehicle 5 to discharge to discharge power to the power grid G. More specifically, the charge / discharge controller 17 causes the vehicle 5 to discharge 10[kW] of power to the power grid G for approximately 18.9[min] until the DOD reaches 10[%], in other word, until the SOC drops from 70[%] to 60[%]. The charge / discharge controller 17 terminates the discharge from the vehicle 5 when the DOD reaches 10[%], and proceeds to the next turn. Thus, in the third turn, the electric energy (3.15[kWh]) for 10[%] DOD is discharged from vehicle 5 to power grid G.
[0113] While one embodiment of the present invention has been described above, the present invention is not limited to this. Detailed configurations may be changed as appropriate within a scope of gist of the present invention.
Claims
1. A charge and discharge management system for managing charge and discharge of an electric vehicle fleet connected to a power grid via charge and discharge facilities, comprising: a battery information acquirer configured to acquire battery information including an SOC of an on-board battery of an individual vehicle constituting the electric vehicle fleet; a participant configurator configured to set a plurality of vehicles satisfying a predetermined condition from among the electric vehicle fleet as discharge participants; a priority configurator configured to set a priority order corresponding to an order of discharge to the power grid for a plurality of the discharge participants based on the SOC of the on-board battery; a charge and discharge controller configured to select at least one of a plurality of the discharge participants in descending order of the priority order and to cause the selected vehicle to discharge to the power grid when a discharge request is generated by the power grid; and a discharge depth calculator configured to calculate a depth of discharge of the on-board battery based on the battery information, wherein the charge and discharge controller terminates discharge of a vehicle during discharge when the depth of discharge of the on-board battery reaches a predetermined threshold value, and starts discharge of a vehicle in next priority order.
2. The charge and discharge management system according to claim 1, wherein the priority configurator sets the priority order for a plurality of the discharge participants in descending order of the SOC of the on-board battery.
3. The charge and discharge management system according to claim 1, wherein the battery information includes an SOH corresponding to health of the on-board battery, and the priority configurator sets the priority order for a plurality of the discharge participants based on the SOC and the SOH of the on-board battery.
4. The charge and discharge management system according to claim 1, wherein the participant configurator sets a vehicle with the SOC of the on-board battery higher than a discharge allowable threshold as the discharge participant among a plurality of vehicles constituting the electric vehicle fleet, and the charge and discharge controller terminates discharge of a vehicle during discharge when the depth of discharge of the on-board battery reaches the threshold value, even if the SOC of the on-board battery is higher than the discharge allowable threshold.
5. The charge and discharge management system according to claim 4, wherein the participant configurator sets a vehicle that does not elapse a predetermined charge / discharge waiting period after charging or discharging the on-board battery until the depth of discharge reaches the threshold value as a discharge non-participant.
6. A charge and discharge management system for managing charge and discharge of an electric vehicle fleet connected to a power grid via charge and discharge facilities, comprising: a battery information acquirer configured to acquire battery information including an SOC of an on-board battery of an individual vehicle constituting the electric vehicle fleet; a participant configurator configured to set a plurality of vehicles satisfying a predetermined condition from among the electric vehicle fleet as charge participants; a priority configurator configured to set a priority order corresponding to an order of charge from the power grid for a plurality of the charge participants based on the SOC of the on-board battery; a charge and discharge controller configured to select at least one of a plurality of the charge participants in descending order of the priority order and to cause the selected vehicle to charge from the power grid when a charge request is generated by the power grid; and a discharge depth calculator configured to calculate a depth of discharge of the on-board battery based on the battery information, wherein the charge and discharge controller terminates charge of a vehicle during charge when the depth of discharge of the on-board battery reaches a predetermined threshold value, and starts charge of a vehicle in next priority order.
7. The charge and discharge management system according to claim 6, wherein the priority configurator sets the priority order for a plurality of the charge participants in ascending order of the SOC of the on-board battery.
8. The charge and discharge management system according to claim 6, wherein the battery information includes an SOH corresponding to health of the on-board battery, and the priority configurator sets the priority order for a plurality of the charge participants based on the SOC and the SOH of the on-board battery.
9. The charge and discharge management system according to claim 6, wherein the participant configurator sets a vehicle with the SOC of the on-board battery lower than a charge allowable threshold as the charge participant among a plurality of vehicles constituting the electric vehicle fleet, and the charge and discharge controller terminates charge of a vehicle during charge when the depth of discharge of the on-board battery reaches the threshold value, even if the SOC of the on-board battery is lower than the charge allowable threshold.
10. The charge and discharge management system according to claim 9, wherein the participant configurator sets a vehicle that does not elapse a predetermined charge / discharge waiting period after charging or discharging the on-board battery until the depth of discharge reaches the threshold value as a charge non-participant.