Power conditioning system and aggregation device

Abstract

The present invention relates to a power conditioning system and an aggregation device. A power conditioning system that conditions charging and discharging power of electrified vehicles in a virtual power plant using a plurality of electrified vehicles as energy resources. The power conditioning system includes a first processor configured to manage charging and discharging of the electrified vehicles based on vehicle information of each individual electrified vehicle included in the electrified vehicles, and a second processor configured to control charging and discharging between the electrified vehicles and a plurality of chargers and dischargers connected to a power distribution network based on charging and discharging information provided from the first processor. The charging and discharging information is generated based on the vehicle information of each individual electrified vehicle and includes charging and discharging constraints of a group of electrified vehicles composed of the electrified vehicles and charging and discharging constraints of each individual electrified vehicle.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a power conditioning system that conditions charging and discharging power of electrified vehicles in a virtual power plant (VPP) using a plurality of electrified vehicles as energy resources, and an aggregation device that constitutes such a power conditioning system. BACKGROUND

[0002] A virtual power plant (VPP) that uses a plurality of electrified vehicles, including a pure battery electric vehicle that uses only a battery as an energy source, and a plug-in hybrid electric vehicle, as energy resources is being increasingly researched. Japanese Patent No. 5905836 (JP 5905836 B) discloses an example of one VPP. SUMMARY

[0003] One of the problems in realizing a VPP is to reliably secure as many power conditioning means as possible. Electrified vehicles as energy resources contribute to balancing a power distribution grid by discharging power from a battery and charging a battery with surplus power. Therefore, the more the number of electrified vehicles incorporated into a VPP system, the better. However, as the number of electrified vehicles to be managed at the same time increases, it becomes more difficult to manage them with a single system, and it becomes necessary for a plurality of aggregators to cooperate. In this case, it is necessary to realize appropriate charging and discharging as a whole while limiting information transmission between aggregators as much as possible from the viewpoint of privacy and the like.

[0004] An object of the present disclosure is to provide a power conditioning system and an aggregation device that can use a large number of electrified vehicles as energy resources of a VPP.

[0005] One aspect of the present disclosure relates to a power conditioning system that conditions charging and discharging power of electrified vehicles in a virtual power plant using a plurality of electrified vehicles as energy resources. The power conditioning system includes a first processor configured to manage charging and discharging of the electrified vehicles based on vehicle information of each individual electrified vehicle included in the electrified vehicles, and a second processor configured to control charging and discharging between the electrified vehicles and a plurality of chargers and dischargers connected to a power distribution grid based on charging and discharging information supplied from the first processor. The charging and discharging information is generated based on the vehicle information of each individual electrified vehicle, and includes charging and discharging constraints of a group of electrified vehicles composed of the electrified vehicles and charging and discharging constraints of each individual electrified vehicle.

[0006] In the above aspect, the charging and discharging information can further include a desired state of charge of the group of electrified vehicles. In the above aspect, the charging and discharging information can further include a desired state of charge of each of the individual electrified vehicles. In the above aspect, the first processor can be configured to control the charging and discharging between the electrified vehicles and the chargers and the dischargers based on the vehicle information of each of the individual electrified vehicles. In the above aspect, the second processor can be connected to a first group of chargers and dischargers included in the chargers and the dischargers, and the first processor can be connected to a second group of chargers and dischargers included in the chargers and the dischargers, the second group of chargers and dischargers being different from the first group of chargers and dischargers.

[0007] One aspect of the present disclosure relates to an aggregation device constituting a power conditioning system that conditions charging and discharging power of electrified vehicles in a virtual power plant using a plurality of electrified vehicles as energy resources. The aggregation device includes a processor configured to: manage charging and discharging of the electrified vehicles based on vehicle information of each of the individual electrified vehicles included in the electrified vehicles; and communicate with a second processor that controls charging and discharging between the electrified vehicles and a plurality of chargers and dischargers connected to a power distribution network, and transmit charging and discharging information required for charging and discharging control to the second processor. The charging and discharging information is generated based on the vehicle information of each of the individual electrified vehicles, and includes charging and discharging constraints of a group of electrified vehicles constituted by the electrified vehicles and charging and discharging constraints of each of the individual electrified vehicles.

[0008] In the above aspect, the charging and discharging information can further include a desired state of charge of the group of electrified vehicles. In the above aspect, the charging and discharging information can further include a desired state of charge of each of the individual electrified vehicles. In the above aspect, the processor can be configured to control the charging and discharging between the electrified vehicles and the chargers and the dischargers based on the vehicle information of each of the individual electrified vehicles. In the above aspect, the second processor can be connected to a first group of chargers and dischargers included in the chargers and the dischargers, and the first processor can be connected to a second group of chargers and dischargers included in the chargers and the dischargers, the second group of chargers and dischargers being different from the first group of chargers and dischargers.

[0009] One aspect of the present disclosure relates to an aggregation device constituting a power conditioning system that conditions charging and discharging power of electrified vehicles in a virtual power plant using a plurality of electrified vehicles as energy resources. The aggregation device includes a processor configured to: communicate with a first processor that manages charging and discharging of electrified vehicles, and receive charging and discharging information from the first processor; and control charging and discharging between the electrified vehicles and a plurality of chargers and dischargers connected to a power distribution network based on the charging and discharging information. The charging and discharging information includes charging and discharging constraints of a group of electrified vehicles constituted by the electrified vehicles and charging and discharging constraints of each individual electrified vehicle included in the electrified vehicles.

[0010] In the above aspect, the charging and discharging information can further include desired state of charge of the group of electrified vehicles. In the above aspect, the charging and discharging information can further include desired state of charge of each individual electrified vehicle. Among the chargers and dischargers, the aggregation device according to the above aspect can be connected to a group of chargers and dischargers different from a group of chargers and dischargers to which the first processor is connected.

[0011] In the power conditioning system according to the present disclosure, a superior aggregation device (first aggregation device) including a first processor manages charging and discharging of electrified vehicles serving as energy resources of a VPP. An inferior aggregation device (second aggregation device) including a second processor controls charging and discharging between the electrified vehicles and chargers and dischargers connected to a power distribution network. That is, the power conditioning system according to the present disclosure has a hierarchical structure including the superior aggregation device and the inferior aggregation device.

[0012] The superior aggregation device manages charging and discharging of the electrified vehicles based on vehicle information of each individual electrified vehicle, while the inferior aggregation device controls charging and discharging between the electrified vehicles and the chargers and dischargers based on charging and discharging information generated in accordance with the vehicle information of each individual electrified vehicle. The charging and discharging information is information including charging and discharging constraints of a group of electrified vehicles constituted by the electrified vehicles and charging and discharging constraints of each individual electrified vehicle. The content of the charging and discharging information is more restricted than the content of the vehicle information of each individual electrified vehicle. The inferior aggregation device controls charging and discharging between the electrified vehicles and the chargers and dischargers within a range in which control constraints are satisfied, i.e., charging and discharging constraints of the group of electrified vehicles and charging and discharging constraints of each individual electrified vehicle are satisfied.

[0013] As described above, the power conditioning system according to the present disclosure includes, in addition to the upper-level aggregation device that manages charging and discharging of the electrified vehicles, a lower-level aggregation device, and causes the lower-level aggregation device to control charging and discharging between the electrified vehicles and the charger and the discharger. The lower-level aggregation device can control charging and discharging of the electrified vehicles with high flexibility as long as the imposed control constraints are satisfied. According to the power conditioning system of the present disclosure configured as described above, a large number of electrified vehicles can be used as energy resources of the VPP. According to the first and second aggregation devices of the present disclosure, a power conditioning system having the above-described effects can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0014] Features, advantages, and technical and industrial significance of exemplary embodiments of the present application will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein:

[0015] Figure 1 An overall configuration of a VPP according to an embodiment of the present disclosure is shown;

[0016] Figure 2 is a block diagram showing a configuration of an upper-level aggregation server and a lower-level aggregation server according to an embodiment of the present disclosure;

[0017] Figure 3 An overview of model predictive control performed by the upper-level aggregation server according to an embodiment of the present disclosure is shown;

[0018] Figure 4 An example of an optimal solution of SOC calculated by the model predictive control and an allowable SOC range set based on the optimal solution is shown;

[0019] Figure 5 An example of a vehicle group desired SOC, a vehicle group SOC upper limit, and a vehicle group SOC lower limit included in charging and discharging information is shown;

[0020] Figure 6 An example of a single vehicle desired SOC, a single vehicle SOC upper limit, and a single vehicle SOC lower limit included in charging and discharging information is shown;

[0021] Figure 7 is a flowchart of a process performed by the power conditioning system of an embodiment of the present disclosure; and

[0022] Figure 8 is a block diagram showing a modification of a configuration of the power conditioning system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0023] Embodiments of the present disclosure will be described below with reference to the accompanying drawings. When a number, a quantity, an amount, a range, etc. of each element in the following embodiments are mentioned, the idea of the present disclosure is not limited to the mentioned numerical value unless otherwise stated, or unless the number, the quantity, the amount, the range, etc. of the element is obviously limited to the mentioned numerical value in principle. The structure described in the following embodiments is not necessarily essential to the idea of the present disclosure unless otherwise stated, or unless the structure is obviously limited to the mentioned structure in principle.

[0024] 1. Overall configuration of VPP

[0025] Figure 1 An overall configuration of a virtual power plant (VPP) 2 of an embodiment of the present disclosure is shown. The VPP 2 of the present embodiment is a VPP that uses a plurality of electrified vehicles 8 as energy resources. Each electrified vehicle 8 used in the VPP 2 is a vehicle that includes a battery 8a and a charging and discharging system. The electrified vehicle 8 includes, for example, a battery electric vehicle (BEV) and a plug-in hybrid electric vehicle (PHEV). The BEV is an electric vehicle that runs on an electric motor using only the battery 8a as an energy source. The BEV can be equipped with a range extender. The PHEV is an electrified vehicle that includes an electric motor and an internal combustion engine, and can directly charge the battery 8a that is an energy source of the electric motor from the outside. The electrified vehicle 8 can be a single type of electrified vehicle or a mixture of a plurality of types of electrified vehicles. The type of the electrified vehicle includes not only a difference between the BEV and the PHEV, but also a difference in the capacity of the battery 8a.

[0026] A plurality of chargers and dischargers 6 connected to the power distribution grid 4 are prepared in the VPP 2. The electrified vehicles 8 used as energy resources of the VPP 2 are connected to the power distribution grid 4 via the chargers and dischargers 6. The chargers and dischargers 6 are used to charge the batteries 8a of the electrified vehicles 8 from the power distribution grid 4, and to discharge the batteries 8a of the electrified vehicles 8 to the power distribution grid 4. However, not all of the electrified vehicles can be connected to the power distribution grid 4. The electrified vehicles capable of being connected to the power distribution grid 4 are limited to the electrified vehicles 8 belonging to the electrified vehicle group 80 of the VPP 2.

[0027] The VPP 2 of the present embodiment includes an energy management system (EMS) server 20, a driving behavior information server 30, a vehicle information server 40, and a power conditioning system 10. The EMS server 20 is a server that constitutes an energy management system of the VPP 2. The EMS server 20 monitors the power distribution grid 4, predicts supply and demand, and requests the power conditioning system 10, which will be described later, to adjust the amount of power. The energy management system can be, for example, a factory energy management system (FEMS) of a factory or a community energy management system (CEMS) of a community.

[0028] The driving behavior information server 30 is a server that manages the driving behavior of the driver of each of the electrified vehicles 8 of the electrified vehicle group 80. The driving behavior information server 30 records the history of past driving behavior of each driver and the future driving plan of each driver. The driving plan can be registered by the driver, or can be estimated from the history of the driving behavior. The driving behavior information server 30 transmits the driving plan information of each of the electrified vehicles 8 associated with each driver to the power conditioning system 10.

[0029] The vehicle information server 40 is a server that manages the vehicle information of each of the electrified vehicles 8 of the electrified vehicle group 80. The vehicle information includes the vehicle identification (ID) that identifies each of the electrified vehicles 8, the current position of each of the electrified vehicles 8, the travel distance of each of the electrified vehicles 8, and the state of charge (SOC) of the battery 8a of each of the electrified vehicles 8. The vehicle information server 40 extracts the vehicle information from each of the electrified vehicles 8 of the electrified vehicle group 80 individually through mobile communication such as fourth generation (4G) or fifth generation (5G), and updates the stored vehicle information of each of the electrified vehicles 8 with the latest information. The vehicle information server 40 transmits the updated vehicle information of each of the electrified vehicles 8 to the power conditioning system 10 at a predetermined cycle.

[0030] The power conditioning system 10 is a system that conditions the charge and discharge power of each of the electrified vehicles 8 of the electrified vehicle group 80. The power conditioning system 10 conditions the charge and discharge power based on the request for conditioning the amount of power from the EMS server 20. Specifically, when the supply of power is requested from the EMS server 20 due to a power shortage, the power conditioning system 10 conditions the charge and discharge power of each of the electrified vehicles 8 so that the requested amount of power is discharged from the electrified vehicle group 80 to the power distribution network 4. When the storage of excess power is requested from the EMS server 20, the power conditioning system 10 conditions the charge and discharge power of each of the electrified vehicles 8 so that the requested amount of power is charged from the power distribution network 4 to the electrified vehicle group 80.

[0031] The power conditioning system 10 has a hierarchical structure including a superior aggregation server 11 and an inferior aggregation server 12. In the present embodiment, one server serves as one embodiment of a superior aggregation device, and one server serves as one embodiment of an inferior aggregation device. The superior aggregation server 11 and the inferior aggregation server 12 are connected through a communication network including the Internet. In one example, the superior aggregation server 11 and the inferior aggregation server 12 are run by different aggregators.

[0032] The upper aggregation server 11 is a server that manages charging and discharging of the electrified vehicles 8 of the electrified vehicle group 80. The EMS server 20, the driving behavior information server 30, and the vehicle information server 40 are connected to the upper aggregation server 11 through a communication network including the Internet. The upper aggregation server 11 manages the SOC and the amount of charge or discharge of the battery 8a of the individual electrified vehicle 8 of the electrified vehicle group 80. The upper aggregation server 11 manages the charging and discharging based on the vehicle information of the individual electrified vehicle 8 transmitted from the vehicle information server 40. The vehicle information for managing the charging and discharging includes information on the relationship between the SOC and the amount of deterioration. As will be described in detail later, the upper aggregation server 11 has a function of generating charging and discharging information based on the vehicle information of the individual electrified vehicle 8.

[0033] The lower aggregation server 12 is a server that controls charging and discharging between the electrified vehicles 8 connected to the chargers and dischargers 6 and the chargers and dischargers 6. The lower aggregation server 12 controls the charging and discharging based on the charging and discharging information supplied from the upper aggregation server 11. The charging and discharging information is a command on the charging and discharging transmitted from the upper aggregation server 11 to the lower aggregation server 12. The charging and discharging information includes the desired SOC of the electrified vehicle group 80 and the charging and discharging constraints and the charging and discharging constraints of the individual electrified vehicle 8. The SOC of the electrified vehicle group 80 refers to the percentage of the actual amount of charge power at a certain point in time with respect to the total of the battery capacities of all the electrified vehicles 8 of the electrified vehicle group 80. The charging and discharging information can further include the desired SOC of the individual electrified vehicle 8.

[0034] The lower aggregation server 12 can control the charging and discharging of the chargers and dischargers 6 managed by the lower aggregation server 12. Hereinafter, the group of the chargers and dischargers 6 managed by the lower aggregation server 12 is referred to as the first charger and discharger group 61. The lower aggregation server 12 reports the results of the charging and discharging control to the upper aggregation server 11 as charging and discharging results. The charging and discharging results include the amount of charge or discharge of each electrified vehicle 8 charged or discharged by the lower aggregation server 12.

[0035] The upper aggregation server 11 also has a function of controlling the charging and discharging of the chargers and dischargers 6. However, the lower aggregation server 12 controls the charging and discharging based on the charging and discharging information, whereas the upper aggregation server 11 controls the charging and discharging based on the vehicle information of the individual electrified vehicle 8. The upper aggregation server 11 can control the charging and discharging of the chargers and dischargers 6 managed by the upper aggregation server 11. Hereinafter, the group of the chargers and dischargers 6 managed by the upper aggregation server 11 is referred to as the second charger and discharger group 62.

[0036] Each of the chargers and dischargers 6 belongs to either a first charger and discharger group 61 or a second charger and discharger group 62. Each of the chargers and dischargers 6 of the first charger and discharger group 61 is connected to the subordinate aggregation server 12 via a gateway (GW) 6a through a communication network including the Internet. Each of the chargers and dischargers 6 of the second charger and discharger group 62 is connected to the superior aggregation server 11 via a gateway (GW) 6a through a communication network including the Internet. Each of the electrified vehicles 8 of the electrified vehicle group 80 can be connected to both the chargers and dischargers 6 of the first charger and discharger group 61 and the chargers and dischargers 6 of the second charger and discharger group 62.

[0037] 2. Configuration and functional details of the power conditioning system

[0038] Next, the configuration and functions of the power conditioning system 10 will be described in detail. Figure 2 is a block diagram showing the configuration of the superior aggregation server 11 and the subordinate aggregation server 12 that constitute the power conditioning system 10.

[0039] The superior aggregation server 11 includes one or more processors 111 (hereinafter simply referred to as processors 111) and one or more memories 112 (hereinafter simply referred to as memories 112) coupled to the processors 111. The memories 112 include a main storage device and a secondary storage device. The memories 112 store programs executable by the processors 111 and various types of information related to the programs. Various processes performed by the processors 111 are implemented by the processors 111 executing the programs. The programs can be stored in the main storage device, or can be stored in a computer-readable recording medium as the secondary storage device.

[0040] The memory 112 stores vehicle information 113 and charge and discharge information 114. The vehicle information 113 exists for all of the electrified vehicles 8 of the electrified vehicle group 80, and the memory 112 stores the vehicle information 113 of each electrified vehicle 8. The vehicle information 113 includes at least SOC-deterioration amount information 113a about a relationship between the SOC and the deterioration amount of the battery 8a. As described above, the charge and discharge information 114 is information generated from the vehicle information 113. The charge and discharge information 114 includes a vehicle group desired SOC 114a, a vehicle group SOC upper limit 114b, a vehicle group SOC lower limit 114c, a single vehicle SOC upper limit 114e, and a single vehicle SOC lower limit 114f. The vehicle group desired SOC 114a is a desired SOC of the electrified vehicle group 80. The vehicle group SOC upper limit 114b and the vehicle group SOC lower limit 114c are charge and discharge constraints of the electrified vehicle group 80. The single vehicle SOC upper limit 114e and the single vehicle SOC lower limit 114f are charge and discharge constraints of the single electrified vehicle 8. The charge and discharge information 114 can include a single vehicle desired SOC 114d. The single vehicle desired SOC 114d is a desired SOC of the single electrified vehicle 8.

[0041] The lower-level aggregation server 12 includes one or more processors 121 (hereinafter simply referred to as processors 121) and one or more memories 122 (hereinafter simply referred to as memories 122) coupled to the processors 121. The memories 122 include a main storage device and a secondary storage device. The memories 122 store programs executable by the processors 121 and various types of information related to the programs. Various processes performed by the processors 121 are implemented by the processors 121 executing the programs. The programs can be stored in the main storage device, or can be stored in a computer-readable recording medium as the secondary storage device.

[0042] The memory 122 stores charge and discharge information 123. In other words, the memory 122 does not store vehicle information, but only stores the charge and discharge information 123. The charge and discharge information 123 stored in the memory 122 is the charge and discharge information 114 transmitted from the superior aggregation server 11. The superior aggregation server 11 transmits the charge and discharge information 114 stored in the memory 112 to the inferior aggregation server 12 at a predetermined period, and updates the charge and discharge information 114 stored in the memory 112 at a predetermined period. The inferior aggregation server 12 updates the charge and discharge information 123 stored in the memory 122 with the charge and discharge information 114 transmitted from the superior aggregation server 11. The charge and discharge information 123 includes a vehicle group desired SOC 123a, a vehicle group SOC upper limit 123b, a vehicle group SOC lower limit 123c, a single vehicle SOC upper limit 123e, and a single vehicle SOC lower limit 123f. When the charge and discharge information 114 includes a single vehicle desired SOC 114d, the charge and discharge information 123 also includes a single vehicle desired SOC 123d.

[0043] When the charge and discharge information 114 is generated, the superior aggregation server 11 first calculates a desired SOC of a single electrified vehicle 8, that is, a single vehicle desired SOC 114d. For example, a model predictive control controller (MPC controller) is used to calculate the single vehicle desired SOC 114d. Figure 3 An overview of model predictive control performed by the superior aggregation server 11 is shown. The MPC controller includes a prediction model and an optimization solver. The prediction model predicts the behavior of the SOC of the battery 8a and the behavior of the state of deterioration for a predetermined period from the current time (prediction horizon). The optimization solver obtains a control input of a single vehicle as a controlled object, that is, a control input of a single electrified vehicle 8, by solving an optimization problem while satisfying constraints. The constraints include a requested charge and discharge power of the electrified vehicle group 80 in addition to preventing the battery 8a from running out of power and the battery 8a having a user-specified SOC. The MPC controller calculates a single vehicle desired SOC as a control input of a single electrified vehicle 8. A single vehicle SOC as a control output, that is, a SOC of a single electrified vehicle 8, is fed back to the MPC controller together with a charge and discharge power of the single electrified vehicle 8. Although model predictive control is used to calculate the single vehicle desired SOC 114d, the means for calculating the single vehicle desired SOC 114d is not limited to model predictive control as long as it is a model-based control that is capable of estimating a future state and taking into account constraints.

[0044] The superior aggregation server 11 calculates the allowable SOC range based on the single-vehicle desired SOC 114d that is the optimal solution of the SOC calculated by the model predictive control and the SOC-deterioration amount information 113a. The allowable SOC range is an SOC range that is allowed from the viewpoint of deterioration of the battery 8a. The upper limit of the allowable SOC range is the single-vehicle SOC upper limit 114e, and the lower limit of the allowable SOC range is the single-vehicle SOC lower limit 114f. Figure 4 Examples of the optimal solution of the SOC calculated by the model predictive control and the allowable SOC range set based on the optimal solution are shown.

[0045] Figure 4 The graphs of each of the examples shown show the content of the SOC-deterioration amount information 113a. The abscissa of each graph indicates the SOC of the battery, and the ordinate of each graph indicates the deterioration amount of the battery capacity. In each graph, an example of the relationship between the SOC and the deterioration amount is shown by a broken line. The relationship between the SOC and the deterioration amount shown by the broken line is the SOC-deterioration amount information 113a. The relationship between the SOC and the deterioration amount is different for each battery depending on the usage history, usage environment, individual differences, and the like of the battery 8a. Therefore, the SOC-deterioration amount information 113a is different for each electrified vehicle 8. In each graph, the optimal solution of the SOC is indicated by a circle, and the allowable SOC range is indicated by double arrows. The allowable SOC range is set to a range in which the rate of increase of the deterioration amount with respect to the deterioration amount at the optimal solution of the SOC is an allowable value (for example, 1%) or less.

[0046] Examples 1 to 3 will be briefly described. In Example 1, the optimal solution of the SOC is lower than the SOC at which the deterioration amount is the minimum (minimum deterioration amount SOC). In this case, as the SOC becomes lower than the optimal solution of the SOC, the deterioration amount increases, and the rate of increase of the deterioration amount rapidly reaches the allowable value. On the other hand, as the SOC becomes higher than the optimal solution of the SOC, the deterioration amount decreases. As the SOC further increases and becomes higher than the minimum deterioration amount SOC, the deterioration amount increases and eventually reaches the allowable value. That is, in Example 1, there is little margin for negative deviation of the SOC from the optimal solution of the SOC, but there is a margin for positive deviation of the SOC from the optimal solution of the SOC.

[0047] In Example 2, the optimal solution of the SOC is the minimum deterioration amount SOC. In this case, as the SOC becomes lower than the optimal solution of the SOC, the deterioration amount increases, and the rate of increase of the deterioration amount eventually reaches the allowable value. As the SOC becomes higher than the optimal solution of the SOC, the deterioration amount also increases, and the rate of increase of the deterioration amount eventually reaches the allowable value. That is, in Example 2, there is a certain amount of margin for negative deviation of the SOC from the optimal solution of the SOC, and there is also a certain amount of margin for positive deviation of the SOC from the optimal solution of the SOC.

[0048] In Example 3, the optimal solution of the SOC is higher than the minimum deterioration amount SOC. Figure 4 The illustrated SOC-deterioration amount characteristic is a characteristic in which the deterioration amount sharply increases as the SOC becomes higher. Therefore, as the SOC becomes higher than the optimal solution of the SOC, the deterioration amount sharply increases, and the rate of increase of the deterioration amount rapidly reaches the allowable value. On the other hand, as the SOC becomes lower than the optimal solution of the SOC, the deterioration amount decreases. As the SOC further decreases and becomes lower than the minimum deterioration amount SOC, the deterioration amount increases but remains lower than the deterioration amount at the optimal solution of the SOC. That is, in Example 3, there is little margin for positive deviation of the SOC from the optimal solution of the SOC, but there is sufficient margin for negative deviation of the SOC from the optimal solution of the SOC.

[0049] The superior aggregation server 11 calculates the vehicle group desired SOC 114a, the vehicle group SOC upper limit 114b, and the vehicle group SOC lower limit 114c based on the individual vehicle desired SOCs 114d, the individual vehicle SOC upper limits 114e, and the individual vehicle SOC lower limits 114f calculated for the individual electrified vehicles 8. The vehicle group desired SOC 114a is calculated as the average of the individual vehicle desired SOCs 114d of all the electrified vehicles 8 of the electrified vehicle group 80. The vehicle group SOC upper limit 114b is calculated as the average of the individual vehicle SOC upper limits 114e of all the electrified vehicles 8 of the electrified vehicle group 80. The vehicle group SOC lower limit 114c is calculated as the average of the individual vehicle SOC lower limits 114f of all the electrified vehicles 8 of the electrified vehicle group 80.

[0050] Figure 5 Examples of the vehicle group desired SOC, the vehicle group SOC upper limit, and the vehicle group SOC lower limit included in the charge and discharge information transmitted from the superior aggregation server 11 to the inferior aggregation server 12 are shown. As shown in Figure 5 As shown, the vehicle group desired SOC, the vehicle group SOC upper limit, and the vehicle group SOC lower limit are variables that change over time. The superior aggregation server 11 transmits these values to the inferior aggregation server 12 at predetermined time intervals.

[0051] Figure 6 Examples of the individual vehicle desired SOC, the individual vehicle SOC upper limit, and the individual vehicle SOC lower limit included in the charge and discharge information transmitted from the superior aggregation server 11 to the inferior aggregation server 12 are shown. As shown in Figure 6 As shown, the individual vehicle desired SOC, the individual vehicle SOC upper limit, and the individual vehicle SOC lower limit are variables that change over time. The superior aggregation server 11 transmits these values to the inferior aggregation server 12 at predetermined time intervals. However, as described above, transmission of the individual vehicle desired SOC is optional, and the charge and discharge information does not necessarily include the individual vehicle desired SOC.

[0052] The lower-level aggregation server 12 controls charging and discharging of the electric vehicles 8 of the chargers and dischargers 6 connected to the first charger and discharger group 61 so as to control the total SOC toward the vehicle group desired SOC 123a while keeping the total SOC within a range from the vehicle group SOC upper limit 123b to the vehicle group SOC lower limit 123c. The lower-level aggregation server 12 also controls charging and discharging of the individual electric vehicles 8 so as to keep the SOC of each individual electric vehicle 8 within a range from its individual vehicle SOC upper limit 123e to its individual vehicle SOC lower limit 123f. When the charging and discharging information includes the individual vehicle desired SOC 123d, the lower-level aggregation server 12 controls charging and discharging of the individual electric vehicles 8 so as to control the SOC of each individual electric vehicle 8 toward its individual vehicle desired SOC 123d while keeping the SOC of each individual electric vehicle 8 within a range from its individual vehicle SOC upper limit 123e to its individual vehicle SOC lower limit 123f.

[0053] When the upper-level aggregation server 11 controls charging and discharging, the upper-level aggregation server 11 performs charging and discharging control based on the vehicle information 113 of the individual electric vehicles 8. The vehicle information 113 used in this charging and discharging control includes at least the SOC-deterioration amount information 113a and the individual vehicle desired SOC 114d. By controlling charging and discharging of each individual electric vehicle 8 based on the SOC-deterioration amount information 113a, the SOC of the individual electric vehicles 8 can be accurately controlled toward their individual vehicle desired SOC 123d while preventing the batteries 8a from rapidly deteriorating and becoming fully charged or depleted.

[0054] Figure 7 is a flowchart of the process performed by the power conditioning system 10 having the above-described configuration and functions. Five steps S1 to S5 are shown in the flowchart. The power conditioning system 10 repeatedly performs these steps S1 to S5 in this order.

[0055] In step S1, the upper-level aggregation server 11 calculates, by model predictive control (MPC), optimal SOC values that minimize deterioration of the battery 8a of each electric vehicle 8. The method of calculating the optimal SOC values by model predictive control is as described above with reference to Figure 3 .

[0056] In step S2, the upper-level aggregation server 11 finds, based on the optimal SOC values, for each electric vehicle 8, an SOC range in which the increase rate of the deterioration amount is an allowable value or less, i.e., an allowable SOC range. The method for finding the allowable SOC range is as described above with reference to Figure 4 .

[0057] In step S3, the superior aggregation server 11 generates charge and discharge information 114 based on the optimal SOC value calculated in step S1 and the allowable SOC range found in step S2. The charge and discharge information 114 includes a vehicle group desired SOC 114a, a vehicle group SOC upper limit 114b, a vehicle group SOC lower limit 114c, a single vehicle SOC upper limit 114e, and a single vehicle SOC lower limit 114f. The charge and discharge information 114 can include a single vehicle desired SOC 114d. The superior aggregation server 11 transmits the charge and discharge information 114 to the inferior aggregation server 12.

[0058] In step S4, the inferior aggregation server 12 performs aggregation control on the electrified vehicles 8 based on the charge and discharge information 123 received from the superior aggregation server 11. The electrified vehicles 8 subject to the aggregation control by the inferior aggregation server 12 are the electrified vehicles 8 connected to the chargers and dischargers 6 of the first charger and discharger group 61. The electrified vehicles 8 connected to the chargers and dischargers 6 of the second charger and discharger group 62 are subject to the aggregation control by the superior aggregation server 11.

[0059] In step S5, the inferior aggregation server 12 reports the charge and discharge results to the superior aggregation server 11. The superior aggregation server 11 acquires the charge and discharge results reported from the inferior aggregation server 12 as the aggregation results. When the superior aggregation server 11 controls the charge and discharge, the superior aggregation server 11 acquires the charge and discharge results of the superior aggregation server 11 itself and the charge and discharge results reported from the inferior aggregation server 12 as the aggregation results. The superior aggregation server 11 reports the aggregation results, i.e., the actual values of the total amount of electric power charged to and discharged from the electrified vehicle group 80, to the EMS server 20.

[0060] 3. Functions and effects of the power conditioning system

[0061] In the power conditioning system 10 of the present embodiment, the superior aggregation server 11 manages the charge and discharge of all the electrified vehicles 8 serving as energy resources of the VPP 2. The superior aggregation server 11 and the inferior aggregation server 12 control the charge and discharge between the electrified vehicles 8 connected to the chargers and dischargers 6 and the chargers and dischargers 6.

[0062] The superior aggregation server 11 manages the charge and discharge of the single electrified vehicles 8 based on the vehicle information 113 of each single electrified vehicle 8, and controls the charge and discharge of the electrified vehicles 8 connected to the chargers and dischargers 6 of the second charger and discharger group 62. The superior aggregation server 11 controls the charge and discharge so as to control the SOC of each single electrified vehicle 8 to its single vehicle desired SOC 114d while referring to the SOC-deterioration amount information 113a included in the vehicle information 113.

[0063] The lower-level aggregation server 12 controls charging and discharging of the electrified vehicles 8 to the chargers and dischargers 6 connected to the first charger and discharger group 61 based on the charging and discharging information 123 generated from the vehicle information 113 of the individual electrified vehicles 8. The lower-level aggregation server 12 performs charging and discharging control so as to achieve the vehicle group desired SOC 123a within a range where the control constraints included in the charging and discharging information 123 are satisfied, i.e., within a range where the vehicle group SOC upper limit 123b, the vehicle group SOC lower limit 123c, the individual vehicle SOC upper limit 123e, and the individual vehicle SOC lower limit 123f are satisfied.

[0064] As described above, the power conditioning system 10 includes the lower-level aggregation server 12 in addition to the upper-level aggregation server 11, and also causes the lower-level aggregation server 12 to control charging and discharging between the electrified vehicles 8 and the chargers and dischargers 6. The upper-level aggregation server 11 controls charging and discharging based on the vehicle information 113 of each individual electrified vehicle 8 including the SOC-deterioration amount information 113a. Therefore, the total requested charging and discharging power of the individual electrified vehicles 8 can be satisfied while minimizing deterioration of the batteries 8a of the individual electrified vehicles 8. The lower-level aggregation server 12 cannot use the detailed vehicle information 113 used by the upper-level aggregation server 11. However, this means that the charging and discharging control of the lower-level aggregation server 12 will not be limited by the contents of the vehicle information 113. That is, the lower-level aggregation server 12 can control charging and discharging with high flexibility as long as the imposed control constraints are satisfied.

[0065] Furthermore, the upper-level aggregation server 11 does not necessarily have to pass the vehicle information 113 of each individual electrified vehicle 8 including the SOC-deterioration amount information 113a to the lower-level aggregation server 12. This is very advantageous when the aggregators running the upper-level aggregation server 11 and the aggregators running the lower-level aggregation server 12 are different entities. For example, when the vehicle information 113 contains highly confidential information, it is very disadvantageous for the aggregators running the upper-level aggregation server 11 to disclose the vehicle information 113 to the aggregators running the lower-level aggregation server 12. However, it is not too disadvantageous for the aggregators running the upper-level aggregation server 11 to disclose the charging and discharging information limited to the above contents to the aggregators running the lower-level aggregation server 12. On the contrary, the aggregators running the upper-level aggregation server 11 can incorporate the aggregators running the lower-level aggregation server 12 into the VPP 2 by disclosing the minimum necessary information. This makes it possible to use more electrified vehicles 8 as energy resources of the VPP 2 compared to the case where the VPP 2 is composed of only the aggregators running the upper-level aggregation server 11.

[0066] 4. Modification of the power conditioning system

[0067] Figure 8 is a block diagram showing a modification of the configuration of the power conditioning system 10. In Figure 8 In the modification shown, the power conditioning system 10 is composed of one superior aggregation server 11 and a plurality of inferior aggregation servers 12-1, 12-2,..., and 12-n. These inferior aggregation servers 12-1, 12-2,..., and 12-n can be operated by different aggregators. First charger and discharger groups 61-1, 61-2,..., and 61-n, which are independent of each other, are connected to the inferior aggregation servers 12-1, 12-2,..., and 12-n, respectively. By connecting the inferior aggregation servers 12-1, 12-2,..., and 12-n to the superior aggregation server 11, more electrified vehicles 8 can be used as energy resources of the VPP 2.

[0068] Although not shown in the figure, the superior aggregation server 11 can be configured to manage only charging and discharging of the electrified vehicles 8. That is, the power conditioning system 10 can be configured so that the inferior aggregation server(s) 12 exclusively controls charging and discharging between the electrified vehicles 8 and the chargers and dischargers 6.

Claims

1. An electric power regulating system regulating charging and discharging power of a plurality of electrified vehicles in a virtual power plant using the plurality of electrified vehicles as energy resources, the electric power regulating system comprising: a first processor configured to manage charging and discharging of the plurality of electrified vehicles based on vehicle information of each individual electrified vehicle included in the plurality of electrified vehicles, wherein the electric power regulating system is characterized by further comprising a second processor configured to control charging and discharging between the plurality of electrified vehicles and a plurality of chargers and dischargers connected to a power distribution network based on charging and discharging information supplied from the first processor, wherein the charging and discharging information is a command on charging and discharging, the charging and discharging information is generated based on the vehicle information of each individual electrified vehicle, and includes charging and discharging constraints of a group of electrified vehicles consisting of the plurality of electrified vehicles and charging and discharging constraints of each individual electrified vehicle.

2. The power conditioning system of claim 1, wherein, the charging and discharging information further includes a desired state of charge of the group of electrified vehicles.

3. The power conditioning system of claim 1 or 2, wherein, the charging and discharging information further includes a desired state of charge of each individual electrified vehicle.

4. The power conditioning system of claim 1 or 2, wherein, the first processor is configured to control charging and discharging between the plurality of electrified vehicles and the chargers and dischargers based on the vehicle information of each individual electrified vehicle. 5.The electric power regulating system of claim 4, wherein: the second processor is connected to a first group of chargers and dischargers included in the chargers and dischargers; and the first processor is connected to a second group of chargers and dischargers included in the chargers and dischargers, the second group of chargers and dischargers being different from the first group of chargers and dischargers. 6.An aggregation device constituting an electric power regulating system regulating charging and discharging power of a plurality of electrified vehicles in a virtual power plant using the plurality of electrified vehicles as energy resources, the aggregation device comprising a first processor configured to: manage charging and discharging of the plurality of electrified vehicles based on vehicle information of each individual electrified vehicle included in the plurality of electrified vehicles, the aggregation device is characterized by: the first processor is further configured to communicate with a second processor controlling charging and discharging between the plurality of electrified vehicles and a plurality of chargers and dischargers connected to a power distribution network, and transmit charging and discharging information required for controlling charging and discharging to the second processor, wherein the charging and discharging information is a command on charging and discharging, the charging and discharging information is generated based on vehicle information of each individual electrified vehicle, and includes charging and discharging constraints of a group of electrified vehicles consisting of the plurality of electrified vehicles and charging and discharging constraints of each individual electrified vehicle.

7. The polymerization apparatus of claim 6, wherein the charging and discharging information further includes a desired state of charge of the group of electrified vehicles.

8. The polymerization apparatus of claim 6 or 7, wherein The charge and discharge information further includes a desired state of charge of each individual electrified vehicle.

9. The polymerization apparatus of claim 6 or 7, wherein The processor is configured to control charging and discharging between the plurality of electrified vehicles and the chargers and dischargers further based on the vehicle information of each individual electrified vehicle.

10. The polymerization apparatus of claim 9, wherein, In the chargers and dischargers, the aggregation device is connected to a different group of chargers and dischargers than a group of chargers and dischargers to which the second processor is connected.

11. An aggregation device constituting a power conditioning system that conditions charging and discharging power of a plurality of electrified vehicles in a virtual power plant that uses the plurality of electrified vehicles as energy resources, the aggregation device comprising a processor configured to: communicate with a first processor that manages charging and discharging of the plurality of electrified vehicles and receive charge and discharge information from the first processor, The aggregation device is characterized in that: The processor is further configured to control charging and discharging between the plurality of electrified vehicles and a plurality of chargers and dischargers connected to a power distribution network based on the charge and discharge information, wherein The charge and discharge information is a command regarding charging and discharging, and the charge and discharge information includes charging and discharging constraints of a group of electrified vehicles constituted by the plurality of electrified vehicles and charging and discharging constraints of each individual electrified vehicle included in the plurality of electrified vehicles.

12. The polymerization apparatus of claim 11, wherein, The charge and discharge information further includes a desired state of charge of the group of electrified vehicles.

13. The polymerization apparatus of claim 11 or 12, wherein, The charge and discharge information further includes a desired state of charge of each individual electrified vehicle.

14. The polymerization apparatus of claim 11 or 12, wherein, In the chargers and dischargers, the aggregation device is connected to a different group of chargers and dischargers than a group of chargers and dischargers to which the first processor is connected.

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