SOC adjustment device and SOC adjustment method

Abstract

To provide a technology that can meet the demand for power supply and demand adjustment as much as possible in a VPP that uses PHVs as an energy resource.SOLUTION: An SOC adjustment device is applied to a system that predicts a predicted SOC at a time when a PHV is connected to a power system on the basis of the behavior prediction of the PHV participating in the VPP, and determines the charge / discharge amount for the PHV on the basis of the power supply and demand adjustment request from a host system and the predicted SOC. This SOC adjustment device acquires the actual SOC from the PHV through mobile communication with the PHV, instructs the PHV to operate the engine when the actual SOC is insufficient for the predicted SOC, and instructs the PHV to stop the engine when the actual SOC is excessive for the predicted SOC. Thereby, the present SOC adjustment device adjusts the actual SOC of the PHV before the PHV is connected to the power system.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an SOC adjustment device and method for adjusting the SOC of a PHV participating in a VPP before the PHV is connected to a power grid. [Background technology]

[0002] Patent Document 1 discloses a technology for using an electric vehicle connected to a facility such as a home or an office as a storage battery. In the conventional technology disclosed therein, if the charging rate of an electric vehicle connected to the facility is below the lower limit of a target range, discharging from the battery is suppressed, and if the charging rate is above the upper limit of the target range, charging to the battery is suppressed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-150767 A Summary of the Invention [Problem to be solved by the invention]

[0004] Recently, research on VPPs (Virtual Power Plants) that use electric vehicles as energy resources is progressing. In VPPs that use electric vehicles, the amount of charge and discharge for the electric vehicle is determined based on a request for power supply and demand adjustment from a higher-level system such as a power company and a predicted SOC at the time when the electric vehicle is connected to the power grid. However, if the actual SOC at the time when the electric vehicle is connected to the power grid deviates from the predicted SOC, charging and discharging for the electric vehicle cannot be performed as scheduled, and there is a risk that the request for power supply and demand adjustment from the higher-level system cannot be satisfied.

[0005] An object of the present invention is to provide a technique that can meet, as much as possible, the demand for adjusting power supply and demand in a VPP that uses PHVs as an energy resource. [Means for solving the problem]

[0006] The present invention provides an SOC adjustment device for achieving the above object. The SOC adjustment device is applied to a system that predicts a predicted SOC at the time a PHV participating in a VPP is connected to a power grid based on a predicted behavior of the PHV, and determines the amount of charge / discharge for the PHV based on a request for power supply and demand adjustment from a higher-level system and the predicted SOC. The SOC adjustment device adjusts the actual SOC of the PHV before the PHV is connected to the power grid, and obtains the actual SOC from the PHV through mobile communication with the PHV. If the actual SOC is insufficient compared to the predicted SOC, the SOC adjustment device instructs the PHV to operate the engine through mobile communication, and if the actual SOC is excessive compared to the predicted SOC, instructs the PHV to stop the engine through mobile communication.

[0007] In the present SOC adjusting device, adjustment of the actual SOC may be performed on the condition that the time when the PHV is predicted to be connected to the power grid is within a predetermined period from the current time.

[0008] The present invention also provides a SOC adjustment method for achieving the above object. The SOC adjustment method is applied to a system that predicts a predicted SOC at the time a PHV participating in a VPP is connected to a power grid based on a predicted behavior of the PHV, and determines a charge / discharge amount for the PHV based on a request for power supply and demand adjustment from a higher-level system and the predicted SOC. The SOC adjustment method adjusts an actual SOC of a PHV before the PHV is connected to a power grid, and includes a step of acquiring the actual SOC from the PHV through mobile communication with the PHV. The SOC adjustment method further includes a step of instructing the PHV to operate an engine through mobile communication when the actual SOC is insufficient relative to the predicted SOC, and a step of instructing the PHV to stop the engine through mobile communication when the actual SOC is in excess of the predicted SOC. Effect of the Invention

[0009] If the actual SOC is insufficient relative to the predicted SOC, the PHV's engine is operated to operate the generator, which generates electricity and increases the SOC, and the shortage of the actual SOC relative to the predicted SOC is resolved before the PHV is connected to the power grid. On the other hand, if the actual SOC is excessive relative to the predicted SOC, the PHV's engine is stopped to stop power generation, which reduces the SOC due to power consumption by the electric motor, and the excess of the actual SOC relative to the predicted SOC is resolved before the PHV is connected to the power grid. According to the SOC adjustment device and method of the present invention, the PHV is instructed to start and stop the engine so that the SOC at the time the PHV is connected to the power grid is approximately the same as the predicted SOC obtained by behavior prediction, thereby improving the satisfaction of requests for power supply and demand adjustment. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing an overall configuration of a VPP to which a SOC adjusting device according to an embodiment of the present invention is applied. [Diagram 2] 2 is a block diagram showing a configuration of an aggregation server functioning as a SOC adjusting device according to an embodiment of the present invention. FIG. [Diagram 3] 4 is a flowchart showing a method for adjusting an SOC according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, when the number, quantity, amount, range, etc. of each element is mentioned in the following embodiments, the idea of ​​the present invention is not limited to the mentioned numbers unless otherwise specified or clearly specified in principle. Furthermore, the structures, etc. described in the following embodiments are not necessarily essential to the idea of ​​the present invention unless otherwise specified or clearly specified in principle.

[0012] 1. Overall configuration of VPP FIG. 1 is a diagram showing the overall configuration of a VPP (Virtual Power Plant) 2 according to an embodiment of the present disclosure. The VPP 2 according to this embodiment is a VPP that uses a plurality of electric vehicles including at least a PHV (Plug-in Hybrid Vehicle) 12 as an energy resource. The electric vehicles used in the VPP 2 may be EVs (Electric Vehicles) in addition to PHVs. However, in this embodiment, for ease of explanation, it is assumed that all electric vehicles participating in the VPP 2 are PHVs 12. The PHV 12 is an electric vehicle that has an electric motor and an engine (internal combustion engine) and can directly charge a battery 14, which is an energy source for the electric motor, from an external source. The PHV 12 may be, for example, a series type in which the engine power is used to drive a generator to generate electricity and the electric motor is driven by the generated electricity to run the vehicle, or a series-parallel type in which the engine power is used to drive the wheels and the generator is also driven to generate electricity.

[0013] The VPP2 of this embodiment includes an aggregation server 10. The aggregator that operates the aggregation server 10 has a contract with a power company for adjusting the supply and demand of electricity. If the aggregator is able to achieve the adjustment of the supply and demand of electricity as specified in the contract, the power company pays the aggregator a reward. However, if the aggregator is unable to achieve the adjustment of the supply and demand of electricity as specified in the contract, the aggregator must pay a penalty to the power company. Therefore, the aggregation server 10 is required to meet the demand for adjusting the supply and demand of electricity as much as possible.

[0014] The aggregation server 10 is connected to a power company server 4, which is a higher-level system, via a communication network. The aggregation server 10 receives a request for power supply and demand adjustment from the power company server 4, and creates a charge and discharge plan for each PHV 12 participating in the VPP 2 so as to satisfy the request. When the PHV 12 is connected to the power grid 6, charging and discharging are performed between the PHV 12 and the power grid 6 according to the charge and discharge plan. The charge and discharge plan for the PHV 12 is created based on the supply and demand adjustment amount requested by the power company server 4 and a predicted SOC at the time when the PHV 12 is connected to the power grid 6. The predicted SOC is important information for creating a charge and discharge plan in order to estimate how much power can be charged to the battery 14 or how much power can be discharged from the battery 14, and also from the viewpoint of suppressing deterioration of the battery 14 due to excessive charging and discharging.

[0015] The aggregation server 10 is connected to the PHV 12 via a mobile communication network. The PHV 12 continuously transmits its location information and SOC information of the battery 14 to the aggregation server 10 via mobile communication. The aggregation server 10 predicts the behavior of the PHV 12 based on the location information of the PHV 12, and predicts when the PHV 12 will be connected to the power grid 6 based on the behavior prediction. Then, based on the predicted time of connection of the PHV 12 to the power grid 6 and the current SOC information of the battery 14, it calculates a predicted SOC at the time of connection. The calculation of the predicted SOC is performed when a charge / discharge plan is created and updated.

[0016] The VPP 2 is provided with a plurality of chargers / dischargers 8 connected to the power system 6. The PHV 12, which serves as an energy resource for the VPP 2, is connected to the power system 6 via the chargers / dischargers 8. Charging of the battery 14 of the PHV 12 from the power system 6 and discharging from the battery 14 of the PHV 12 to the power system 6 are performed using the chargers / dischargers 8. The chargers / dischargers 8 operate according to charge / discharge instructions from the aggregation server 10.

[0017] First, when the PHV 12 is connected to the charger / discharger 8, the PHV 12 transmits vehicle information of the PHV 12 to the charger / discharger 8. The charger / discharger 8 is connected to the aggregation server 10 via a wired or wireless communication network. The charger / discharger 8 requests the aggregation server 10 to issue a charge / discharge instruction for the PHV 12 identified by the vehicle information. The aggregation server 10 transmits a charge / discharge instruction to the charger / discharger 8 according to a charge / discharge plan for the PHV 12 identified by the vehicle information. The charger / discharger 8 receives the charge / discharge instruction from the aggregation server 10 and performs a charge / discharge operation for the PHV 12. After the charge / discharge operation is completed, the charger / discharger 8 transmits the actual charge amount or discharge amount obtained by the charge / discharge operation, that is, the charge / discharge result, to the aggregation server 10. The aggregation server 10 compiles the charge / discharge results reported from each charger / discharger 8 to create a power supply / demand adjustment result, and reports the power supply / demand adjustment result to the power company server 4.

[0018] However, if there is a discrepancy between the predicted SOC used to create the charge / discharge plan and the SOC at the time when the PHV 12 is actually connected to the charger / discharger 8, there is a risk that charging or discharging cannot be performed as planned. For example, if a discharging operation is performed on the battery 14 when the actual SOC is lower than the predicted SOC, the SOC may reach the lower limit of the appropriate range, and the amount of discharge may not be obtained as instructed by the aggregation server 10. Also, if a charging operation is performed on the battery 14 when the actual SOC is higher than the predicted SOC, there is a risk that the SOC may reach the upper limit of the appropriate range, and the amount of charge may not be obtained as instructed by the aggregation server 10.

[0019] In order to achieve the power supply and demand adjustment requested by the power company server 4, it is necessary to obtain the charge or discharge amount according to the charge and discharge plan from each PHV 12. To achieve this, it is required that the SOC at the time when the PHV 12 is connected to the power grid 6 via the charger / discharger 8 is approximately the same as the predicted SOC obtained by behavior prediction, i.e., the predicted SOC used to create the charge and discharge plan. For this reason, in this embodiment, the aggregation server 10 has a function as an SOC adjustment device that adjusts the actual SOC of the PHV 12 before the PHV 12 is connected to the power grid 6.

[0020] 2. Configuration and Function of SOC Adjustment Device Next, a description will be given of the configuration and functions of the aggregation server 10 as a SOC adjusting device. Fig. 2 is a block diagram showing the configuration of the aggregation server 10 functioning as a SOC adjusting device.

[0021] The aggregation server 10 includes a processor 110 and a memory 120 coupled to the processor 110. The memory 120 stores programs executable by the processor 110 and various information related to the programs. The processor 110 executes the programs to realize various processes by the processor 110. The programs stored in the memory 120 include a charge / discharge instruction program 121 and an SOC adjustment program 122. The aggregation server 10 further includes a storage 130. The storage 130 stores a vehicle information database 131. The vehicle information database 131 is a database that manages position information and SOC information for each PHV 12 acquired by communication with the PHV 12.

[0022] By executing the charge / discharge instruction program 121 in the processor 110, the aggregation server 10 creates a charge / discharge plan for each PHV 12 and transmits a charge / discharge instruction to the charger / discharger 8 to which the PHV 12 is connected. The aggregation server 10 predicts the predicted SOC at the time when the PHV 12 is connected to the power grid 6 based on the behavior prediction, and creates a charge / discharge plan based on the power supply / demand adjustment request from the power company server 4 and the predicted SOC. In other words, the aggregation server 10 functions as a system that predicts the predicted SOC at the time when the PHV 12 is connected to the power grid 6 based on the behavior prediction of the PHV 12, and determines the amount of charge / discharge for the PHV 12 based on the request for power supply / demand adjustment from the upper system and the predicted SOC. In addition, by executing the SOC adjustment program 122 in the processor 110, the processor 110 causes the aggregation server 10 to function as a SOC adjustment device.

[0023] 3 is a flowchart showing a SOC adjustment method by the aggregation server 10 as a SOC adjusting device. The aggregation server 10 executes the SOC adjustment according to this flowchart for each of all PHVs 12 participating in the VPP2.

[0024] First, in step S10, the aggregation server 10 predicts whether or not the power supply and demand adjustment requested by the power company server 4 can be achieved under the current charging and discharging status of the PHV 12. If it is predicted that the power supply and demand adjustment can be achieved, there is no need for SOC adjustment, and the process according to this flowchart ends.

[0025] If it is predicted that power supply and demand adjustment cannot be achieved, the aggregation server 10 executes step S20. In step S20, the aggregation server 10 determines whether the PHV 12 is connected to the power grid 6. If the PHV 12 is already connected to the power grid 6, it is no longer necessary to perform SOC adjustment, and the process according to this flowchart ends.

[0026] If the PHV 12 is not connected to the electric power grid 6, the aggregation server 10 executes step S30. In step S30, the aggregation server 10 predicts when the PHV 12 will be connected to the electric power grid 6 based on the location information of the PHV 12, and determines whether the predicted connection time of the PHV 12 to the electric power grid 6 is within a predetermined period from the current time. In other words, the aggregation server 10 determines whether the connection of the PHV 12 to the electric power grid 6 will be performed in the near future.

[0027] If it takes time for the PHV 12 to be connected to the power grid 6, the SOC of the battery 14 may change significantly from the current state depending on the operating state of the PHV 12. Therefore, if the PHV 12 is not likely to be connected to the power grid 6 within a predetermined period from the current time, the aggregation server 10 suspends the SOC adjustment and repeats the determinations of steps S20 and S30.

[0028] When it is predicted that the PHV 12 will be connected to the power grid 6 in the near future, the aggregation server 10 executes step S40. In step S40, the aggregation server 10 compares the predicted SOC used to create the charge / discharge plan with the actual SOC at the current time acquired from the PHV 12 via mobile communication.

[0029] If the comparison result in step S40 shows that the actual SOC is lower than the predicted SOC, the aggregation server 10 executes step S50. In step S50, the aggregation server 10 compares the fuel cost required to operate the engine of the PHV 12 to recover the SOC with the penalty to be paid if the power supply and demand adjustment is not achieved. The fuel cost fluctuates, and the penalty is not necessarily constant depending on the contract contents. For this reason, the judgment result in step S50 is not fixed to either one. If the penalty is cheaper than the fuel cost, there is no need to operate the engine of the PHV 12 to adjust the SOC, and the processing according to this flowchart ends.

[0030] If the fuel cost is cheaper than the penalty, there is an advantage in operating the engine of the PHV 12 to adjust the SOC. In this case, the aggregation server 10 executes step S60. In step S60, the aggregation server 10 transmits an engine operation command to the PHV 12 by mobile communication. When the PHV 12 operates the engine, the engine drives a generator, which generates electricity. This power generation increases the SOC of the battery 14, and the shortage of the actual SOC relative to the predicted SOC is resolved before the PHV 12 is connected to the power grid 6.

[0031] If the comparison result in step S40 shows that the actual SOC is not lower than the predicted SOC, the aggregation server 10 executes step S70. In step S70, the aggregation server 10 determines whether the actual SOC is higher than the predicted SOC. If the actual SOC is not higher than the predicted SOC, that is, if the predicted SOC and the actual SOC are equivalent, there is no need to adjust the SOC, and the process according to this flowchart ends.

[0032] If the actual SOC is higher than the predicted SOC, the aggregation server 10 executes step S80. In step S80, the aggregation server 10 transmits an engine stop command to the PHV 12 by mobile communication. When the PHV 12 stops the engine, the engine also stops driving the generator, and power generation by the generator stops. This halt in power generation reduces the SOC of the battery 14, and the excess of the actual SOC relative to the predicted SOC is eliminated before the PHV 12 is connected to the power grid 6.

[0033] As described above, according to the SOC adjustment method of the present embodiment, the PHV 12 is instructed to operate / stop the engine so that the SOC of the battery 14 at the time when the PHV 12 is connected to the power grid 6 is approximately equal to the predicted SOC obtained by behavior prediction. This improves the degree of satisfaction of the power supply and demand adjustment request, and makes it possible to stably adjust the power supply and demand in accordance with the contract with the power company. [Explanation of symbols]

[0034] 2 VPP 4. Electric power company server 6 Power system 8 Charger / discharger 10 Aggregation Server 12 PHV 14 Battery 110 Processor 120 Memory 121 Charge / Discharge Instruction Program 122 SOC Adjustment Program 130 Storage 131 Vehicle Information Database

Claims

1. A system for predicting a predicted SOC of a PHV participating in a VPP at the time the PHV is connected to a power grid based on a behavior prediction of the PHV, and determining an amount of charge / discharge for the PHV based on a request for power supply / demand adjustment from a higher-level system and the predicted SOC, comprising: an SOC adjustment device for adjusting an actual SOC of the PHV before the PHV is connected to the power grid, the SOC adjustment device comprising: acquiring the actual SOC from the PHV through mobile communication with the PHV; When the actual SOC is insufficient with respect to the predicted SOC, instructing the PHV to operate an engine via the mobile communication; When the actual SOC is excessive with respect to the predicted SOC, the PHV is instructed to stop the engine via the mobile communication. An SOC adjustment device characterized by:

2. 2. The SOC adjusting device according to claim 1, The actual SOC is adjusted on the condition that the time when the PHV is predicted to be connected to the power grid is within a predetermined period from the current time. An SOC adjustment device characterized by:

3. A method for adjusting an actual SOC of a PHV before the PHV is connected to a power grid, the method comprising: predicting a predicted SOC of the PHV when the PHV is connected to a power grid based on a behavior prediction of the PHV; and determining an amount of charge / discharge for the PHV based on a request for power supply / demand adjustment from a higher-level system and the predicted SOC; acquiring the actual SOC from the PHV through mobile communication with the PHV; When the actual SOC is insufficient with respect to the predicted SOC, instructing the PHV to operate an engine via the mobile communication; and when the actual SOC is excessive relative to the predicted SOC, instructing the PHV to stop the engine via the mobile communication. A method for adjusting an SOC.

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