Charging control device, mobile body, charging control system, and charging control method

Abstract

This invention provides a charging control device, a mobile body, a charging control system, and a charging control method. In the charging control device (10), the current SOC and target SOC of the battery (12) and the electricity cost per unit of power of the charging device (18) are obtained. Taking the electricity cost into account, and comparing the current SOC and the target SOC, a charging schedule that minimizes the rate of battery degradation is set accordingly.

Description

Technical Field

[0001] This invention relates to a charging control device, a mobile body, a charging control system, and a charging control method. Background Technology

[0002] Japanese Patent Publication No. 2012-186906 discloses a technology for charging a battery installed in an electric vehicle using an external power source. Specifically, when the next driving date and time of the electric vehicle are set, the battery is charged during a low-fee period just before the next driving date and time.

[0003] Japanese Patent Publication No. 2019-154167 discloses an operation for charging a battery in an electric vehicle. The battery undergoes a first charge and a second charge sequentially over a period from the start of charging to its completion. During the first charge, the battery is charged just before reaching the intermediate state of charge (SOC) region to shorten the dwell time in the SOC region and temperature range where degradation is easily accelerated during charging. During the second charge, the battery is charged to a fully charged state before the completion of charging. Summary of the Invention

[0004] Japanese Patent Publication No. 2012-186906 discloses a battery charging control method that takes into account electricity costs. Japanese Patent Publication No. 2019-154167 discloses a battery charging control method that takes into account battery degradation due to state of charge (SOC). However, neither Japanese Patent Publication No. 2012-186906 nor Japanese Patent Publication No. 2019-154167 thoroughly investigates the need to control battery charging by considering both electricity costs and battery degradation.

[0005] Given the above, it is hoped that electricity costs can be reduced and battery degradation can be suppressed.

[0006] The purpose of this invention is to solve the above-mentioned technical problems.

[0007] A first aspect of the present invention is a charging control device that controls the charging of a battery from an external power source. The charging control device includes: a current SOC acquisition unit that acquires the current SOC of the battery; a target SOC acquisition unit that acquires a target SOC; an electricity cost acquisition unit that acquires the electricity cost per unit of power from the external power source; and a charging time scheduling setting unit that takes into account the electricity cost and compares the current SOC with the target SOC, thereby setting a charging time schedule for the battery with a low rate of degradation.

[0008] The second aspect of the present invention is a movable body having the above-described charging control device and battery.

[0009] The third aspect of the present invention is a charging control system having the above-described charging control device and battery.

[0010] The fourth aspect of the present invention is a charging control method that controls the charging of a battery from an external power source, comprising: a step of a current SOC acquisition unit acquiring the current SOC of the battery; a step of a target SOC acquisition unit acquiring the target SOC of the battery; a step of an electricity cost acquisition unit acquiring the electricity cost per unit of power from the external power source; and a step of a charging time scheduling setting unit considering the electricity cost and comparing the current SOC with the target SOC to set a charging time schedule for the battery with a low rate of degradation acceleration.

[0011] In this invention, the battery charging time schedule is set by considering both electricity costs and the battery's degradation characteristics (battery deterioration susceptibility) before and after charging. By charging the battery from an external power source according to this charging time schedule, electricity costs can be reduced and battery degradation can be suppressed.

[0012] The above-described objectives, features, and advantages should be readily understood from the following description of the embodiments with reference to the accompanying drawings. Attached Figure Description

[0013] Figure 1 It is a block diagram including a charging control device and a vehicle charging control system according to one embodiment. Figure 2 This is an explanatory diagram illustrating the concept of one implementation method. Figure 3 This is a graph showing the relationship between SOC and the rate of battery degradation. Figure 4A and Figure 4B This is a graph showing the relationship between the rate of degradation and electricity costs. Figure 5 It is a graph representing the time elapsed for the evaluation function (evaluation value). Figure 6 This is a flowchart of the charging control process. Figure 7 This is a flowchart of the charging control process. Detailed Implementation

[0014] Figure 1This is a block diagram of a charging control system 14 having a charging control device 10 and a battery 12 according to one embodiment. The charging control system 14 includes a vehicle 16, a charging device 18, a management server 20, and a smart device 22. The vehicle 16 is a mobile body carrying the battery 12. The charging device 18 is an external power source for the vehicle 16. The smart device 22 is an information communication device used by a user. The user is the user of the battery 12. The user is also the user of the vehicle 16. The charging control device 10 controls the charging of the battery 12 from the charging device 18 into the vehicle 16. In the following description, the case where the management server 20 is the charging control device 10 will be explained.

[0015] In this embodiment, the moving body can be an object that can be moved (driven) by a power supply from the battery 12. This embodiment is applicable to various moving bodies such as two-wheeled, three-wheeled, and four-wheeled vehicles, aircraft, and ships. This embodiment is not limited to moving bodies, and can also be applied to the charging control of the battery 12 in various devices driven by a power supply from the battery 12.

[0016] In this embodiment, such as Figure 1 As shown, the case where the battery 12 is charged by the charging device 18 in an insertion manner will be described. In this embodiment, the charging device 18 can charge the battery 12 via a contactless power supply method.

[0017] When the moving body is vehicle 16, vehicle 16 includes an electric vehicle that is driven by an electrical supply from battery 12. Alternatively, vehicle 16 can also be a hybrid vehicle. A hybrid vehicle has a motor and an internal combustion engine. The motor is driven by an electrical supply from battery 12.

[0018] In this embodiment, the ECU (not shown) inside the vehicle 16 can also be the charging control device 10. Alternatively, the smart device 22 can also be the charging control device 10.

[0019] Vehicle 16 includes battery 12, charging implementation unit 24, vehicle display 26, communication control unit 28, and charging port 30. Charging device 18 is installed, for example, at the site of a user's residence. Cable 32 extends from charging device 18. A charging connector 34 (charging gun) is provided at the end of cable 32. When vehicle 16 is located at the site, the user inserts charging connector 34 into charging port 30. When charging connector 34 is inserted into charging port 30, charging device 18 can charge battery 12. With charging connector 34 connected to charging port 30, charging implementation unit 24, under control from management server 20, causes charging device 18 to charge battery 12. Charging implementation unit 24 can use various sensors to acquire various information related to vehicle 16. Among the various information related to vehicle 16 is information related to battery 12. This information includes, for example, the state of charge (SOC) of battery 12, the temperature of battery 12, and the outside air temperature of vehicle 16. In the following description, the temperature of battery 12 will be referred to as battery temperature.

[0020] The in-vehicle display 26 is a navigation device or similar device found in the vehicle 16. The in-vehicle display 26 displays various information as images. The in-vehicle display 26 can also output various information as voice. The in-vehicle display 26 has an operating unit, such as a touchscreen that accepts user input.

[0021] The communication control unit 28 is capable of sending and receiving information with the management server 20 and the smart device 22 via wireless communication. For example, the communication control unit 28 receives instructions related to the charging control of the battery 12 from the management server 20 and outputs these instructions to the charging implementation unit 24. The communication control unit 28 also sends various information related to the battery 12 obtained by the charging implementation unit 24 to the management server 20.

[0022] The management server 20 includes a communication unit 36, a control unit 38 (comprising a current SOC acquisition unit, a target SOC acquisition unit, an electricity cost acquisition unit, a charging schedule setting unit, a scheduled drive time acquisition unit, a degradation acceleration degree acquisition unit, and an evaluation value acquisition unit), and a storage unit 42. The storage unit 42 includes an electricity cost table storage unit 39 and a vehicle history record storage unit 40. The control unit 38 is the CPU of the management server 20. The control unit 38 functions as a charging plan determination unit 44 by reading and executing programs stored in the storage unit 42. The charging plan determination unit 44 sets charging schedules, etc. The charging schedule is a time arrangement for the charging device 18 to charge the battery 12. The specific functions of the charging plan determination unit 44 will be described later.

[0023] The communication unit 36 ​​is capable of sending and receiving information wirelessly with the communication control unit 28 of the vehicle 16. The communication unit 36 ​​is also capable of sending and receiving information wirelessly with the smart device 22. The communication unit 36 ​​receives, for example, various information related to the vehicle 16. This information includes, as mentioned above, the state of charge (SOC), battery temperature, and ambient air temperature.

[0024] The communication unit 36 ​​can receive electricity cost information per unit of electricity used by the charging device 18 from the power company with which the user has a contract. Alternatively, the communication unit 36 ​​can receive electricity cost information per unit of electricity used by the charging device 18 from the aggregator who coordinates the user and the power company. Specifically, the electricity cost information is the charging scheme for the charging device 18 and the electricity cost as a function of time (electricity cost function). The received charging scheme for the charging device 18 is stored in the electricity cost table storage unit 39. Therefore, the electricity cost table based on the user's contract is stored in the electricity cost table storage unit 39. Alternatively, in the case of a floating price table charging contract where the electricity cost is variable in minutes based on the daily electricity supply and demand balance, the communication unit 36 ​​automatically updates the electricity cost table in the electricity cost table storage unit 39 by periodically communicating with the power company or aggregator.

[0025] The intelligent device 22 includes a communication unit 46, a display unit 48, and an operation unit 50. The communication unit 46 can send and receive information wirelessly with the communication unit 36 ​​of the management server 20. The communication unit 46 can also send and receive information wirelessly with the communication control unit 28 of the vehicle 16. The display unit 48 displays various information as images. The operation unit 50 includes a touchscreen or similar device that accepts user input.

[0026] Next, while referring to Figures 2 to 4B The concept of charging control for the battery 12 according to this embodiment will be explained. In the charging control of this embodiment, the charging scheme and the battery 12 before and after charging (see reference) are considered. Figure 1 The charging time schedule for battery 12 is set based on the degradation characteristics of battery 12 (its inherent susceptibility to degradation). Furthermore, in charging control, by having the charging device 18 charge battery 12 according to the set charging time schedule, it is possible to reduce electricity costs while suppressing battery degradation.

[0027] Figure 2 This is an explanatory diagram illustrating the concept of charging control in this embodiment. Figure 2 In the middle, the user drives 16 vehicles (refer to...) Figure 1 The user returns to their home. Afterwards, the charging device 18 charges the battery 12. The battery 12 is charged during the period from when the user returns home until the user drives the vehicle 16 away from their home. As an example, this illustrates a billing contract where electricity fees vary based on time of day. Figure 2 This indicates a shift from high to low charges, followed by a shift to medium charges. Furthermore, this implementation method can be easily applied to contracts with floating price schedules. In floating price schedules, the cost per unit of electricity varies flexibly based on the balance of electricity supply and demand, for example, in 30-minute increments. In the following description, the cost per unit of electricity will also be referred to as the electricity unit price.

[0028] As mentioned above, in the methods of Japanese Patent Publication No. 2012-186906 and Japanese Patent Publication No. 2019-154167, the battery 12 is charged to a full charge before the predetermined time when the vehicle 16 departs from the residence. In the following description, the predetermined time when the vehicle 16 departs from the residence is referred to as the predetermined departure time t_start (predetermined driving time). However, in the prior art method, the battery 12 is sometimes more prone to degradation after charging is completed compared to before charging begins. In addition, if the battery 12 is charged during a low-fee period considering the charging scheme, electricity costs can be reduced.

[0029] Figure 3 This indicates battery 12 (refer to...) Figure 1 The relationship between the SOC of battery 12 and the degree of accelerated degradation. Figure 3 As shown, in the region where the SOC is less than 50%, the rate of degradation of battery 12 increases with increasing SOC. In the region where the SOC is above 50% but less than 70%, the rate of degradation of battery 12 decreases with increasing SOC. In the region where the SOC is above 70%, the rate of degradation of battery 12 increases with increasing SOC.

[0030] Strictly speaking, the rate of degradation of battery 12 depends on battery temperature. As an example, Figure 3 The degree of accelerated degradation of battery 12 is shown when the battery temperature is Tb1, Tb2 (Tb1 < Tb2).

[0031] Therefore, depending on the SOC (State of Charge) value, the degradation of battery 12 can sometimes be accelerated. For example, as... Figure 3 As shown, the degradation of battery 12 accelerates significantly when the SOC is around 50% and above 90%. Therefore, when charging battery 12 with a target SOC that accelerates degradation, the degradation of battery 12 is likely to be accelerated after charging is completed.

[0032] For example, in Figure 2 In "Condition 1", in vehicle 16 (refer to) Figure 1After returning home, battery 12 was not charged within the specified time. In condition 1, battery 12 was charged after time tcs1 during the low-charge period. When left uncharged for the specified time, battery 12 may experience a decrease in its battery capacity (SOH) due to storage degradation. However, if the SOC immediately after returning home is around 20%, storage degradation occurs relatively slowly even without charging within the specified time. In condition 1, battery 12 was charged after time tcs1, i.e., after the specified time since returning home, to increase the SOC from around 20% to around 70%. The degradation rate is faster at 70% SOC than at 20%. Therefore, when battery 12 is charged at 70% SOC, the decrease in SOH due to storage degradation is relatively greater. That is, in condition 1, battery 12 is more prone to degradation after charging compared to before charging began.

[0033] exist Figure 2 In Condition 2, after vehicle 16 returns home, charging of battery 12 begins at the initial moment (tcs2) during the low-toll period. In Condition 2, the State of Charge (SOC) before charging begins is approximately 45%. In Condition 2, the target SOC for charging battery 12 is approximately 70%. The rate of degradation acceleration is greater at an SOC of 45% than at an SOC of 70%. Therefore, under Condition 2, the degradation of battery 12 is more likely to accelerate before charging begins compared to after charging is complete.

[0034] Thus, the rate of degradation of battery 12 varies depending on the state of charge (SOC). Therefore, in this embodiment, battery 12 is charged in a manner that minimizes the rate of degradation.

[0035] Figure 4A and Figure 4B This indicates battery 12 (refer to...) Figure 1 A graph showing the relationship between the rate of degradation and electricity costs. Figure 4A and Figure 4B The relationship between the rate of degradation of battery 12 and electricity costs is expressed using the time when charging of battery 12 begins as a parameter. In the following explanation, the time when charging of battery 12 begins is referred to as the charging start time tcs. Figure 4A This is a graph showing the relationship between TCS at the start of charging, the rate of degradation, and electricity costs. Figure 4A The example shown is a case where the SOC is charged from 50% to 80%. Figure 4B This is a graph showing the relationship between TCS at the start of charging, the rate of degradation, and electricity costs. Figure 4B The example shown is a case where the SOC is charged from 20% to 80%.

[0036] exist Figure 4A In this case, setting the charging start time (TCS) to 22 can reduce electricity costs and suppress battery degradation after charging is complete. Figure 4A In this context, 22:00 is the optimal charging start time tcs. In the following explanation, the optimal charging start time tcs will be referred to as the optimal time tcs_opt. Figure 4B In this case, setting the charging start time (TCS) to 23 can reduce electricity costs and suppress battery degradation after charging is complete. Figure 4B In the above, 23:00 is the optimal time tcs_opt.

[0037] In this way, the electricity cost for each time period and the qualitative deterioration of battery 12 before and after charging can be considered, and charging of battery 12 can begin from the optimal time tcs_opt. That is, the electricity cost for each time period and the degradation characteristics of battery 12 before and after charging can be considered, and charging of battery 12 can begin from the optimal time tcs_opt. Accordingly, it is possible to reduce electricity costs while suppressing the degradation of battery 12 after charging is completed.

[0038] Next, while referring to Figures 5-7 The specific charging control is explained below. This specific charging control is... Figures 2 to 4B A specific example of the concept of charging control is shown.

[0039] In this specific example, such as Figure 5 As shown, the user's vehicle 16 (reference) Figure 1 Vehicle 16 returns to its residence at 18:00 (time t1) the previous day. Vehicle 16 departs from its residence at 8:00 the next day. Therefore, the scheduled departure time t_start is 8:00 the next day. Furthermore, battery 12 must be charged no later than the scheduled departure time t_start. In this specific example, battery 12 is charged at 7:00 the next day. That is, in this specific example, a leeway is considered in the specified time Tm (Tm = 1 time) to complete the charging of battery 12. In the following explanation, the final time at which the charging of battery 12 should be completed is referred to as the charging completion time tcf.

[0040] The charging time Tc of battery 12 is determined based on the current SOC value (current SOC), the target SOC value (target SOC), the characteristics of the charging device 18, and the ambient temperature of battery 12. The characteristics of the charging device 18 can be categorized as either normal charging or rapid charging. In this specific example, to reliably complete charging of battery 12 before the charging completion time tcf, a charging start time tcs (optimal time tcs_opt) needs to be set. In this case, by calculating the charging time Tc from the charging completion time tcf, the latest charging start time t_const can be calculated. Therefore, when charging of battery 12 begins before the charging start time t_const, charging of battery 12 is completed before the charging completion time tcf. Conversely, when charging of battery 12 begins after the charging start time t_const, charging of battery 12 is not completed by the charging completion time tcf.

[0041] The pricing scheme is set by the electricity company with which the user signs the contract. In this scheme, for example, the electricity price varies based on time of day. In this specific example, the electricity price is higher from the time the user returns home (6 PM) to 8 PM. The electricity price is lower than the higher price from 8 PM to 10 PM, which is a medium price. The electricity price is lowest, from 10 PM to 6 AM the next day. The time period after 6 AM the next day is a medium price period.

[0042] In this specific example, the charging start time tcs is optimized by charging battery 12 for the desired charging time Tc, which includes a low-fee period. Accordingly, charging of battery 12 begins at the optimal time tcs_opt before the charging start time t_const. As a result, charging is completed before the charging completion time tcf. This reduces electricity costs and suppresses battery degradation after charging. Furthermore, in this specific example, the following is used... Figure 5 The evaluation function Q(t) shown is used to determine the optimal time tcs_opt. In the following description, for convenience, the value of the evaluation function Q(t) is sometimes referred to as the "comprehensive evaluation value Q(t)".

[0043] The evaluation function Q(t) is used to comprehensively evaluate the electricity cost, the rate of degradation of battery 12, and whether charging has been completed from the start time tcs to the completion time tcf. That is, during the time period from time t1 to the completion time tcf, battery 12 is charged from a certain time ti, and is charged from the current SOC to the target SOC over a charging time Tc(ti). The evaluation function Q(t) is used to comprehensively evaluate the charging of battery 12 over a charging time Tc(ti) by considering both the electricity cost and the rate of degradation of battery 12. Figure 5 As shown, the evaluation function Q(t) can be obtained at each time ti.

[0044] If the charging start time tcs (time ti) changes, the battery temperature at time ti will change due to the influence of the external air temperature of vehicle 16. As a result, the charging time Tc may change. Thus, the charging time Tc depends on the charging start time tcs and the change in battery temperature. In the following explanation, the charging time Tc starting from a certain time ti will also be referred to as the charging time Tc(ti). The charging time Tc starting from the charging start time t_const will also be referred to as the charging time Tc(t_const).

[0045] Specifically, the evaluation function Q(t) is expressed by the following equation (1). Q(t) = k1 × (Electricity cost evaluation function Qcost(t)) + k2 ×(Battery degradation evaluation function Qbat(t))+k3 (1) Here, the first term of equation (1) is called the electricity cost evaluation value. The electricity cost evaluation function Qcost(t) in the electricity cost evaluation value is a function used to evaluate the electricity cost when charging starts from time ti. k1 is the first weighting coefficient of the electricity cost evaluation function Qcost(t). The electricity cost evaluation function Qcost(t) is expressed by the following equation (2). Qcost(t) = Σ(Effective power P(t) of charging device 18) × Electricity price per unit M(t)) (2) P(t) is the effective power supplied from charging device 18 to battery 12 when charging starts at a certain time ti. M(t) is the electricity cost per unit of power (unit price of electricity) when charging starts at a certain time ti. Σ is the mathematical symbol representing the sum of P(t) × M(t) from the start of charging battery 12 to the completion of charging. Equation (2) represents the time integral of the electricity cost from the start of charging battery 12 to the completion of charging. That is, Equation (2) represents the time integral of the electricity cost from time ti to time (ti+Tc(ti)). Therefore, the electricity cost evaluation value at a certain time ti is calculated by integrating the value obtained by multiplying the effective power P(t) of charging device 18 at each time t and the unit price of electricity M(t) from time ti to the completion time (ti+Tc(ti)).

[0046] Furthermore, the effective power P(t) of the charging device 18 depends on (1) the characteristics of the charging device 18, (2) the battery temperature which varies due to the influence of the external air temperature of the vehicle 16, and (3) the operating state of the high-voltage auxiliary equipment (load) mounted on the vehicle 16. Examples of operating states include the air conditioning inside the vehicle 16 and heating of the battery 12. Additionally, the effective power P(t) varies according to the charging start time tcs (time ti). The effective power P(t) of the charging device 18 is generally not constant. Therefore, the effective power P(t) is calculated by predicting the temporal changes in the battery temperature and the operating state of the load of the vehicle 16 from time ti to the charging completion time (ti+Tc(ti)).

[0047] Therefore, even when the battery 12 is heated to operate in a low-temperature environment, the electricity cost assessment value can be calculated with high accuracy. Furthermore, even when the user sets the air conditioner's timer function to operate for a predetermined time Tm according to a pre-set start time t_start, the electricity cost assessment value can still be calculated with high accuracy.

[0048] As shown in equation (2), the higher the electricity cost, the greater the electricity cost evaluation value. Conversely, the lower the electricity cost, the smaller the electricity cost evaluation value.

[0049] The second term of equation (1) is called the battery degradation evaluation value. The battery degradation evaluation function Qbat(t) in the battery degradation evaluation value is used to evaluate the degradation of battery 12 from time ti to the start of charging. k2 is the degree of accelerated degradation relative to battery 12 (refer to...). Figure 3 The second weighting coefficient of the battery degradation evaluation function Qbat(t) is given by equation (3). Qbat(t)=Σk(t)×t (3) k(t) represents the placement degradation characteristics corresponding to the SOC of battery 12. According to Figure 3 The degradation rate of battery 12 is shown to define the placement degradation characteristic k(t). Σ is a mathematical symbol representing the sum of k(t) × t from the start of charging battery 12 to the completion of charging. Equation (3) represents the time integral of the placement degradation characteristic k(t) which varies with the SOC value from the start of charging battery 12 to the completion of charging.

[0050] As mentioned above, strictly speaking, the rate of degradation of battery 12 is accelerated (refer to...). Figure 3The degradation rate depends on the battery temperature. That is, the rate of degradation varies with the battery temperature. Therefore, the placement degradation characteristic k(t) can also be a placement degradation characteristic corresponding to the SOC and battery temperature of the battery 12 as defined according to the rate of degradation of the battery 12. In this case, the placement degradation characteristic k(t) is defined based on the rate of degradation of the battery 12. Equation (3) represents the time integration of the placement degradation characteristic k(t), which varies with SOC and battery temperature, from time t1 to the predetermined start time t_start. Furthermore, in Figure 3 The figure only shows the relationship between SOC and the degree of accelerated degradation of battery 12.

[0051] Therefore, the placement degradation characteristic k(t) can be calculated by predicting the SOC and battery temperature at a certain time ti. That is, the temporal changes in SOC and battery temperature during charging from time ti to the charging completion time (ti+Tc(ti)) can be predicted based on the temporal changes in battery temperature of the battery 12 placed from time t1 to time ti. In addition, the temporal changes in battery temperature of the battery 12 placed from the charging completion time (ti+Tc(ti)) to the predetermined start time t_start can be predicted based on the aforementioned temporal changes in battery temperature. In this way, by considering the temporal changes in battery temperature, the battery degradation evaluation function Qbat(t) (battery degradation evaluation value) can be calculated with high accuracy. Therefore, even under conditions of significantly lower or higher temperatures, the degradation of the battery 12 can be further suppressed.

[0052] According to equation (3), the higher the rate of degradation of battery 12, the greater the battery degradation evaluation value. Conversely, the lower the rate of degradation of battery 12, the smaller the battery degradation evaluation value.

[0053] Based on the information indicating the user's intention, the charging plan determination unit 44 sets coefficients k1 and k2 respectively. The information indicating the user's intention is pre-stored in the vehicle history storage unit 40. Alternatively, the user can set coefficients k1 and k2 respectively by operating the in-vehicle display 26. Furthermore, the user can also set coefficients k1 and k2 respectively by operating the operation unit 50 of the smart device 22.

[0054] Coefficient k3 is the third weighting coefficient indicating whether charging of battery 12 is complete before reaching the charging completion time tcf. This third weighting coefficient will be referred to as the charging completion evaluation value. Here, the evaluation function Q(t) takes a value within the range of 0 to 1. If charging of battery 12 is complete before the charging completion time tcf, coefficient k3 is set to 0. Conversely, if charging of battery 12 is not complete by the charging completion time tcf (the predetermined start time t_start), coefficient k3 is set to 1. That is, if charging of battery 12 is not complete by the charging completion time tcf (the predetermined start time t_start), the evaluation function Q(t) is set to the maximum value within the range that the evaluation function Q(t) can take, which is 1.

[0055] Thus, regarding the charging control of battery 12, the evaluation function Q(t) (comprehensive evaluation value Q(t)) of equation (1) comprehensively evaluates the electricity cost, the degree of accelerated degradation of battery 12, and whether charging has been completed by the charging completion time tcf.

[0056] As mentioned above, the evaluation function Q(t) (comprehensive evaluation value Q(t)) is obtained at any time t. In this specific example, as... Figure 5 As shown, the evaluation function Q(t) decreases as time progresses, starting from the time of returning home t1. After reaching its minimum value (the local minimum), the evaluation function Q(t) increases as time progresses. During the period after the charging start time t_const, the evaluation function Q(t) is fixed at its upper limit.

[0057] Here, when the charging start time tcs is set for the time period from the time of returning home t1 to 22:00, the overall evaluation value Q(t) becomes higher. This is because the electricity cost is relatively high. In addition, this is because the target SOC is reached earlier, so storage degradation is more likely to occur after charging is completed.

[0058] When the charging start time tcs is set for the period from 10 PM to 1 AM the next day, the overall evaluation value Q(t) is lower compared to the period from the time of returning home t1 to 10 PM. This is due to the lower electricity cost. However, when the charging start time tcs is set for this period, the overall evaluation value Q(t) is not significantly reduced because early reaching the target SOC will lead to placement degradation.

[0059] When the charging start time tcs is set for the period from 1:00 AM to 3:00 AM on the second day, the overall evaluation value Q(t) becomes the lowest. This is due to the low electricity cost. Additionally, this is because the target SOC is reached just before the charging completion time tcf, thus suppressing degradation. Furthermore, this is because charging is completed before the charging completion time tcf.

[0060] When the charging start time tcs is set between 3:00 AM and 5:00 AM on the second day, the overall evaluation value Q(t) increases. When the charging start time tcs is set after 5:00 AM on the second day, the overall evaluation value Q(t) becomes the upper limit. That is, if charging starts after the charging start time t_const, charging will not be completed by the charging completion time tcf, therefore, the overall evaluation value Q(t) becomes the upper limit.

[0061] Thus, if the time when the evaluation function Q(t) reaches its minimum value is set as the optimal time tcs_opt, electricity costs will be relatively low. Furthermore, if the time when the evaluation function Q(t) reaches its minimum value is set as the optimal time tcs_opt, battery degradation will be reduced. Moreover, if the time when the evaluation function Q(t) reaches its minimum value is set as the optimal time tcs_opt, charging will be completed before the charging completion time tcf. In other words, if the time when the evaluation function Q(t) reaches its minimum value is set as the optimal time tcs_opt, both reduced electricity costs and suppressed battery degradation can be achieved.

[0062] Figure 6 and Figure 7 This is a flowchart showing the setting process of the optimal time tcs_opt and the charging process of battery 12 from the optimal time tcs_opt to the charging completion time tcf. Figure 6 and Figure 7 The processing is mainly handled by the charging plan judgment unit 44 (refer to...). Figure 1 ) to execute.

[0063] First, the user-driven vehicle 16 (refer to...) Figure 1 Upon returning home, the user inserts the charging connector 34 of the charging device 18 into the charging port 30. Thus, the charging connector 34 and the charging port 30 are connected. The charging implementation unit 24 notifies the charging plan determination unit 44 via the communication control unit 28 and the communication unit 36 ​​that the battery 12 can be charged from the charging device 18.

[0064] exist Figure 6 In step S1, the charging plan determination unit 44 (refer to...) Figure 1 Upon receiving the notification, the charging plan determination unit 44 obtains the electricity charges (charging scheme, electricity charge function) that vary by time period. In this case, the charging plan determination unit 44 obtains the charging scheme that is pre-stored in the electricity charge form storage unit 39. Alternatively, the charging plan determination unit 44 obtains the charging scheme from the power company with which the user has a contract via the communication unit 36. If the charging scheme is obtained from the power company, the obtained charging scheme is stored in the electricity charge form storage unit 39.

[0065] In the vehicle history record storage unit 40, the relationship between SOC, battery temperature, and the rate of degradation of battery 12 is stored in a table. In the next step S2, the charging plan determination unit 44 refers to the vehicle history record storage unit 40 to obtain the rate of degradation of battery 12 relative to SOC and battery temperature.

[0066] In step S3, the charging plan determination unit 44 obtains the predetermined departure time t_start.

[0067] The charging plan determination unit 44 sends a request for a predetermined departure time t_start to the communication control unit 28 of the vehicle 16 via the communication unit 36. Based on the request received by the communication control unit 28, the in-vehicle display 26 prompts the user to input the predetermined departure time t_start. After the user confirms the display content on the in-vehicle display 26, they operate the display 26 to input the predetermined departure time t_start. Accordingly, the charging plan determination unit 44 can obtain the predetermined departure time t_start input by the user via the communication control unit 28 and the communication unit 36.

[0068] Alternatively, the charging plan determination unit 44 can send a request for a predetermined departure time t_start to the communication unit 46 of the smart device 22 via the communication unit 36. Based on the sending request received by the communication unit 46, the display unit 48 of the smart device 22 displays a prompt to input the predetermined departure time t_start. After confirming the display content on the display unit 48, the user operates the operation unit 50 to input the predetermined departure time t_start. Accordingly, the charging plan determination unit 44 can obtain the predetermined departure time t_start input by the user via each of the communication units 36 and 46.

[0069] In step S4, the charging plan determination unit 44 acquires charging device information representing the characteristics of the charging device 18. As described above, the characteristics of the charging device 18 can include whether it performs normal charging or fast charging. The charging plan determination unit 44 refers to the charging device information initially set by the user. Alternatively, if the charging device information is pre-stored in the vehicle history storage unit 40, the charging plan determination unit 44 can refer to the charging device information stored in the vehicle history storage unit 40. Furthermore, if the charging plan determination unit 44 already possesses the charging device information, it can skip the acquisition process in step S4.

[0070] The charging implementation unit 24 uses sensors (not shown) to sequentially acquire various information related to the vehicle 16 (battery 12). This information includes, for example, the state of charge (SOC) of the battery 12, battery temperature, and the external temperature of the vehicle 16. In the next step, S5, the charging plan determination unit 44 acquires various information related to the vehicle 16 from the charging implementation unit 24 via the communication control unit 28 and the communication unit 36.

[0071] In the next step, S6, the charging plan determination unit 44 sets the target SOC. In this case, similar to step S3, the user operates the vehicle display 26 to input the target SOC. Alternatively, the user can also operate the operation unit 50 of the smart device 22 to input the target SOC. The charging plan determination unit 44 sets the target SOC input by the user. Alternatively, the charging plan determination unit 44 can also set the target SOC by referring to the driving history of the vehicle 16 stored in the vehicle history storage unit 40. Furthermore, the target SOC is the SOC corresponding to a sufficient amount of charging required without compromising user convenience. Specifically, the target SOC is the SOC corresponding to the amount of charging required for the next trip of the vehicle 16.

[0072] In the next step S7, the charging plan determination unit 44 predicts the change in battery temperature over time (time-sequence change) after the current moment based on the information obtained in step S5.

[0073] In the next step S8, the charging plan determination unit 44 calculates the charging completion time tcf. The charging completion time tcf is the time that is sufficient from the predetermined start time t_start, taking into account a specified time Tm. Next, the charging plan determination unit 44 calculates the charging time Tc. The charging time Tc is calculated based on the target SOC, the current SOC, charging equipment information, and the temporal changes in battery temperature. Next, the charging plan determination unit 44 calculates the charging start time t_const by back-calculating the charging time Tc based on the charging completion time tcf.

[0074] In the next step S9, the charging plan determination unit 44 determines the evaluation function Q(t) of the above equation (1). As mentioned above, the charging plan determination unit 44 has calculated the electricity cost, the degree of accelerated degradation of the battery 12 (degradation characteristics), and the predetermined departure time t_start.

[0075] Furthermore, the charging plan determination unit 44 sets coefficients k1 and k2 according to the user's intention. For example, regarding the charging of battery 12, if the user prioritizes reducing electricity costs over suppressing battery 12 degradation, coefficient k1 is set to be greater than coefficient k2 (k1 > k2). Conversely, if the user prioritizes suppressing battery 12 degradation over reducing electricity costs, coefficient k2 is set to be greater than coefficient k1 (k1 < k2). Additionally, similar to the acquisition process in step S3, the charging plan determination unit 44 requests information related to the user's intention from the vehicle 16 or the smart device 22 via the communication unit 36. This allows the user to choose whether to prioritize reducing electricity costs or suppressing battery 12 degradation. The charging plan determination unit 44 can set coefficients k1 and k2 based on the user's selection. Alternatively, the vehicle history record storage unit 40 can pre-store information related to the user's intention. The charging plan determination unit 44 can then set coefficients k1 and k2 based on this information.

[0076] If the current time is before the charging start time t_const, then coefficient k3 is set to 0. That is, if charging is completed before the charging completion time tcf, coefficient k3 is set to 0. Conversely, if the current time is after the charging start time t_const, then coefficient k3 is set to 1. That is, if charging is not completed by the charging completion time tcf, coefficient k3 is set to 1.

[0077] Furthermore, k(t) in equation (3) is set based on the SOC at time t, the battery temperature, and the rate of degradation of battery 12.

[0078] In this way, by setting the coefficients and functions of equations (1) to (3), the charging plan judgment unit 44 can determine the evaluation function Q(t).

[0079] exist Figure 7 In step S10, the charging plan determination unit 44 (refer to...) Figure 1 Set the variable i at a certain time ti to 1. That is, set the certain time ti to the time of returning home t1. In addition, the variable i is an integer greater than or equal to 1. Furthermore, the unit of each time can be any of seconds, minutes, or hours.

[0080] In the next step S11, the charging plan determination unit 44 uses equations (1) to (3) to calculate the value of the evaluation function Q(t) when charging of battery 12 begins at the time of returning home t1 (time ti). That is, the charging plan determination unit 44 uses equations (1) to (3) to calculate the comprehensive evaluation value Q(t). In this case, the charging plan determination unit 44 calculates the comprehensive evaluation value Q(t1) when charging of battery 12 begins at the time of returning home t1 for a charging time Tc.

[0081] Furthermore, in the following explanation, for ease of explanation, the evaluation function Q(ti) at time ti will be referred to as the evaluation function Q(i). Additionally, the comprehensive evaluation value Q(ti) will be referred to as the comprehensive evaluation value Q(i).

[0082] In the next step S12, the charging plan determination unit 44 calculates the comprehensive evaluation value Q(i+1) for time t(i+1) which is later than time ti by a predetermined time (time α). In this case, i = 1, therefore, the charging plan determination unit 44 calculates the comprehensive evaluation value Q(t) for time t2. That is, the charging plan determination unit 44 calculates the comprehensive evaluation value Q(t2) for the case where the battery 12 is charged from time t2 for a charging time Tc.

[0083] In the next step S13, the charging plan determination unit 44 compares the value of the evaluation function Q(t) at time ti with the value of the evaluation function Q(t) at time t(i+1) and determines whether Q(i) < Q(i+1). That is, the charging plan determination unit 44 compares the comprehensive evaluation value Q(i) with the comprehensive evaluation value Q(i+1) and determines whether Q(i) < Q(i+1).

[0084] In step S13, if Q(i) < Q(i+1) (step S13: Yes), proceed to step S14. In step S14, the charging plan determination unit 44 sets time ti as the optimal time tcs_opt. When comparing Q(i) and Q(i+1), Q(i) is smaller. Therefore, if charging of battery 12 starts from time ti, charging will be completed before the charging completion time tcf. Therefore, it is possible to reduce electricity costs and suppress battery 12 degradation.

[0085] Furthermore, if Q(i) ≥ Q(i+1) in step S13 (step S13: No), skip step S14 and proceed to step S15. When comparing Q(i) and Q(i+1), Q(i) is greater than Q(i+1). Therefore, even if battery 12 is charged starting from time ti, it is difficult to reduce electricity costs and suppress battery 12 degradation.

[0086] In the next step S15, the charging plan determination unit 44 determines whether the time ti has reached the charging start time t_const.

[0087] If, in step S15, time ti has not reached the charging start time t_const (step S15: No), the process proceeds to step S16. In step S16, the charging plan determination unit 44 accumulates the variable i. After this, it returns to step S12 and repeats the processing of steps S12 to S15. In this way, starting from the return time t1, the charging plan determination unit 44 repeatedly calculates the comprehensive evaluation value Q(i) of time ti and updates the optimal time tcs_opt at predetermined time intervals.

[0088] In step S15, if time ti reaches the charging start time t_const (step S15: Yes), the processing of steps S12 to S16 is completed, and the optimal time tcs_opt is determined.

[0089] In the next step, S17, the charging plan determination unit 44 sends information related to the determined optimal time tcs_opt and information related to the target SOC to the charging implementation unit 24 via the communication unit 36 ​​and the communication control unit 28. That is, the charging plan determination unit 44 sends a charging schedule to the charging implementation unit 24. Accordingly, the charging implementation unit 24, based on the received charging schedule, begins charging the battery 12 if the optimal time tcs_opt is reached.

[0090] After charging begins, the charging implementation unit 24 sequentially acquires the current SOC of the battery 12. In step S18, when the current SOC reaches the target SOC (step S18: Yes), the process proceeds to step S19. In step S19, the charging implementation unit 24 completes the charging of the battery 12. Therefore, charging of the battery 12 can be completed before the charging completion time tcf.

[0091] Furthermore, depending on the country, region, and power company, pricing schemes (times when electricity is cheaper) can vary. Therefore, when conducting... Figure 6 and Figure 7 During processing, the charging plan determination unit 44 can also check the historical record of the previous charging control stored in the vehicle history record storage unit 40. If the electricity cost has not changed between the last processing and the current processing, the previous electricity cost can be used directly. Accordingly, some processing steps S1 and S2 are skipped, thus achieving efficient setting of the charging schedule. However, if the electricity cost has changed between the last charging control and the current charging control, then according to... Figure 6 and Figure 7 The flowcharts are processed sequentially.

[0092] This is performed on the condition that the charging connector 34 of the charging device 18 and the charging port 30 of the vehicle 16 are inserted and connected. Figure 6 and Figure 7The process shown can also be performed when a state is reached where the battery 12 can be charged non-contactly from the charging device 18. Figure 6 and Figure 7 The processing.

[0093] exist Figure 7 In steps S17 and S18, if charging stops due to a circuit breaker tripping in the charging device 18, charging can restart according to the original charging schedule when a start signal (CPL signal) is detected again from the charging device 18. Alternatively, if the charging connector 34 is disconnected from the charging port 30, the charging schedule is not restored. In this case, when the charging connector 34 and the charging port 30 are reconnected, the evaluation function Q(t) related to the charging schedule can be calculated again, and the charging schedule can be reset.

[0094] If the comprehensive evaluation value Q(i) when charging starts from the current time point (time ti) is the same as the comprehensive evaluation value Q(i+1) when charging starts after a specified time (time t(i+1)), then charging can also start after the specified time. That is, when Q(i) = Q(i+1), charging can also start after the specified time. Accordingly, the time t(i+1) corresponding to Q(i+1) is updated to the optimal time tcs_opt.

[0095] In addition, after obtaining Figure 5 In the case of such an evaluation function Q(t), the evaluation function Q(t) for each predetermined time interval within the range from time t1 to the charging completion time tcf can also be calculated. That is, the evaluation function Q(t) for each time ti is calculated by repeating steps S12 to S16.

[0096] Alternatively, if the evaluation function Q(t) is known in advance from the electricity bill table or other sources to have only one downward convex inflection point, the evaluation function Q(t) for each specified time interval after time t1 can be calculated. Steps S12 to S16 are repeated to calculate the evaluation function Q(t) for each time ti. As a result, the point at which the evaluation function Q(t) reverses its upward trend from its minimum value can be determined as the optimal time tcs_opt. In this case, once the optimal time tcs_opt is determined, the processing of steps S12 to S16 can be stopped, and the process can proceed to steps S17 and beyond.

[0097] Alternatively, the specified time interval can be changed while performing multiple calculations to determine the optimal time tcs_opt. That is, the specified time interval can be appropriately changed while performing multiple optimization calculations to explore the optimal time tcs_opt.

[0098] Specifically, in the first calculation, the time α is set to a relatively large value α1. That is, with the specified time interval set to a large value, steps S12 to S16 are repeated. Based on this, the optimal time tcs_opt1 is roughly calculated.

[0099] In the second calculation, the time α is set to a value α2, which is smaller than α1. Next, the evaluation function Q(t) is calculated for the time interval containing the optimal time tcs_opt1 obtained in the first calculation. That is, with time α set to α2, the evaluation function Q(t) for each time interval from time (tcs_opt1-α1) to time (tcs_opt1+α1) is calculated. Then, with time α set to α2, steps S12 to S16 are repeated. Accordingly, with time α set to a relatively small value α2, the evaluation function Q(t) for each time interval ti is calculated. As a result, the optimal time tcs_opt2 is obtained.

[0100] The third calculation also uses the same method as above. That is, the time period and time α are both set to be relatively short, and the optimal time tcs_opt is calculated.

[0101] This reduces the computational load when calculating the optimal time tcs_opt. Furthermore, after the user connects the charging device 18 to the vehicle 16, the optimal time tcs_opt can be set with high precision in a shorter time.

[0102] Furthermore, the present invention is not limited to the above-described embodiments, and various structures can be adopted without departing from the spirit of the present invention.

[0103] The invention that can be obtained according to the above embodiments is described below.

[0104] The first aspect of the present invention is a charging control device (10) that controls the charging of a battery (12) from an external power source (18). The charging control device includes: a current SOC acquisition unit (44) that acquires the current SOC of the battery; a target SOC acquisition unit (44) that acquires a target SOC; an electricity cost acquisition unit (44) that acquires the electricity cost per unit of power from the external power source; and a charging time scheduling setting unit (44) that takes into account the electricity cost and compares the current SOC with the target SOC, thereby setting a charging time schedule for the battery with a low rate of battery degradation.

[0105] In this invention, the battery charging schedule is set by considering both electricity costs and the battery's degradation characteristics (battery deterioration susceptibility) before and after charging. By charging the battery from an external power source according to this charging schedule, it is possible to reduce electricity costs while suppressing battery degradation.

[0106] In a first aspect of the present invention, the charging control device includes: a predetermined drive time acquisition unit (44) that acquires a predetermined drive time (t_start) of a mobile body (16) having the battery; and a degradation acceleration degree acquisition unit (44) that acquires the degradation acceleration degree of the battery, drives the mobile body by power supply from the battery, and, when the battery is in a rechargeable state, determines the degradation acceleration degree of the battery relative to the current SOC and the target SOC based on the degradation acceleration degree acquired by the degradation acceleration degree acquisition unit, and sets a charging time arrangement that keeps the degradation acceleration degree of the battery at a relatively low level during the period up to the predetermined drive time.

[0107] Therefore, by reducing the time that the rate of battery degradation is kept at a high level, battery degradation can be suppressed.

[0108] In the first aspect of the present invention, the charging time scheduling setting unit determines the degree of degradation acceleration of the battery relative to the current SOC and the current battery temperature, and the degree of degradation acceleration of the battery relative to the target SOC and the battery temperature after charging is completed, based on the degree of degradation acceleration obtained by the degradation acceleration acquisition unit, and sets a charging time schedule that keeps the degree of degradation acceleration of the battery at a relatively low level during the period up to the predetermined driving time.

[0109] Therefore, even when the air conditioner is started at a predetermined time according to a pre-set drive time while the battery is being heated in a low-temperature environment, the charging time can be set with high precision.

[0110] In the first aspect of the present invention, the charging control device further includes an evaluation value acquisition unit (44), which acquires the following evaluation values: an evaluation value (Q(i)) regarding the electricity cost and the degree of accelerated battery degradation when charging the battery from the current SOC at the current time (ti) to the target SOC; and an evaluation value (Q(i+1)) regarding the electricity cost and the degree of accelerated battery degradation when charging the battery from the current SOC at a time (t(i+1)) after a predetermined time (α) from the current time to the target SOC. The charging time scheduling setting unit compares the acquired evaluation values ​​and sets the time with the lower evaluation value as the charging start time (tcs, tcs_opt) when actually starting to charge the battery.

[0111] Therefore, it is possible to set a suitable charging start time (optimal time).

[0112] In the first aspect of the present invention, the charging time scheduling setting unit performs the following processing: whenever the evaluation value acquisition unit acquires the evaluation value at the predetermined time interval, it compares the evaluation value at the current time with the evaluation value at the time after the predetermined time. If the evaluation value at the time after the predetermined time is lower, the time with the lower evaluation value is selected. If the evaluation value at the time after the predetermined time is higher than the evaluation value at the current time, the current time is set as the charging start time, thereby stopping the evaluation value acquisition processing performed by the evaluation value acquisition unit.

[0113] Therefore, it is possible to avoid setting a charging start time that has not been completed by the predetermined driving time, while simultaneously achieving efficient setting processing.

[0114] In the first aspect of the present invention, the charging time scheduling setting unit performs the following processing: whenever the evaluation value acquisition unit acquires the evaluation value at the predetermined time interval, it compares the evaluation value at the current time with the evaluation value at the time after the predetermined time, selects the time with the lowest evaluation value, and sets the time with the lowest evaluation value as the charging start time.

[0115] In this case, it is also possible to avoid setting a charging start time when charging has not been completed by the scheduled departure time.

[0116] In the first aspect of the present invention, the charging time scheduling setting unit performs the selection process of the moment with the lowest evaluation value multiple times by making the predetermined time interval variable.

[0117] This reduces the computational load when calculating the charging start time. Furthermore, it allows for more precise setting of the charging start time in a shorter time after the user connects the charging device to the vehicle.

[0118] In a first aspect of the present invention, the charging time scheduling unit sets the time at which the smallest evaluation value among the evaluation values ​​for completing the charging of the battery before the predetermined driving time is set as the charging start time.

[0119] Therefore, it is possible to reliably avoid setting a charging start time when charging has not been completed by the predetermined driving time.

[0120] In the first aspect of the present invention, the evaluation value is the sum of an electricity cost evaluation value, a battery degradation evaluation value, and a charging completion evaluation value (k3). The electricity cost evaluation value is obtained by multiplying the effective power from the external power source to the battery, the unit price of the electricity cost, and a first weighting coefficient (k1). The battery degradation evaluation value is obtained by multiplying the time integral of the degradation characteristic coefficient by a second weighting coefficient (k2), which represents the degradation value of the battery during the time period from the last time the mobile body was driven to the predetermined driving time. The charging completion evaluation value (k3) is a value that evaluates whether the charging of the battery is completed before the predetermined driving time.

[0121] Therefore, the charging start time (optimal time) can be set with high precision.

[0122] In the first aspect of the present invention, when the user of the mobile device values ​​the electricity cost more than the battery degradation, the first weighting coefficient is set to be greater than the second weighting coefficient; when the user values ​​the battery degradation more than the electricity cost, the second weighting coefficient is set to be greater than the first weighting coefficient; when the battery charging is completed before the predetermined driving time, the charging completion evaluation value is set to be low; and when the battery charging is not completed by the predetermined driving time, the charging completion evaluation value is set to be high.

[0123] Therefore, the charging start time (optimal time) can be set with higher precision.

[0124] In the first aspect of the present invention, if the electricity cost of the last charging of the battery and the electricity cost of the current charging of the battery are unchanged, the charging time scheduling setting unit uses the electricity cost of the last charging of the battery to calculate the electricity cost evaluation value.

[0125] Therefore, it is possible to achieve high efficiency in setting charging schedules.

[0126] In the first aspect of the present invention, when the user of the mobile device has signed a floating price list charging contract with variable electricity charges based on the daily balance of electricity supply and demand, the charging time scheduling unit periodically obtains the electricity charges and uses the electricity charges of that day to calculate the electricity charge evaluation value.

[0127] This enables highly efficient scheduling of charging times. Furthermore, in floating price contracts, electricity charges are collected periodically and automatically updated. As a result, electricity cost estimates can be calculated with high accuracy.

[0128] In the first aspect of the present invention, the charging time scheduling setting unit calculates the electricity cost evaluation value by taking into account the temporal changes of the effective power and the unit price of the electricity cost and the first weighting coefficient.

[0129] Therefore, it is possible to set the charging start time (optimal time) with higher precision.

[0130] In a first aspect of the present invention, the charging time scheduling unit sets a charging time schedule in which the battery is charged before a predetermined time (Tm) before the predetermined driving time.

[0131] Therefore, users can have surplus power to start the mobile device.

[0132] The second aspect of the present invention is a movable body having the above-described charging control device and battery.

[0133] The aforementioned effects can also be easily obtained in this invention.

[0134] The third aspect of the present invention is a charging control system (14) having the above-described charging control device and battery.

[0135] The aforementioned effects can also be easily obtained in this invention.

[0136] The fourth aspect of the present invention is a charging control method that controls the charging of a battery from an external power source. The charging control method includes: a step of a current SOC acquisition unit acquiring the current SOC of the battery (step S5); a step of a target SOC acquisition unit acquiring the target SOC of the battery (step S6); a step of an electricity cost acquisition unit acquiring the electricity cost per unit of power from the external power source (step S1); and a step of a charging time scheduling setting unit considering the electricity cost and comparing the current SOC and the target SOC to set a charging time schedule for the battery with a lower rate of degradation acceleration (steps S9 to S16).

[0137] In this invention, the battery charging time schedule is set by considering both electricity costs and the battery's degradation characteristics (battery deterioration susceptibility) before and after charging. By charging the battery from an external power source according to this charging time schedule, electricity costs can be reduced and battery degradation can be suppressed.

Claims

1. A charging control device that controls the charging of a battery from an external power source, characterized in that, have: The current SOC acquisition unit acquires the current SOC of the battery; The target SOC acquisition unit acquires the target SOC. The electricity fee acquisition unit acquires the electricity fee for each unit of electricity from the external power source; The degradation acceleration acquisition unit acquires the degradation acceleration rate of the battery; The evaluation value acquisition unit acquires an evaluation value, which is an evaluation value about the electricity cost and the degree of accelerated degradation of the battery when charging the battery from the current SOC to the target SOC. The lower the electricity cost and the lower the degree of accelerated degradation of the battery, the lower the evaluation value. The charging time scheduling unit sets the charging time schedule for the battery. The charging time scheduling setting unit performs the following processing: Whenever the evaluation value is acquired at a predetermined time interval, the evaluation value at the current moment is compared with the evaluation value at a moment after a predetermined time has elapsed since the current moment, and the lower evaluation value is selected as the first evaluation value. Within a time period from a time before the predetermined time relative to the first evaluation value to a time after the predetermined time relative to the first evaluation value, the evaluation values ​​are sequentially acquired at intervals shorter than the predetermined time. The charging time schedule is set by setting the time when the lowest evaluation value among the multiple obtained evaluation values ​​is actually the start time of charging the battery.

2. The charging control device according to claim 1, characterized in that, It also has: A predetermined drive time acquisition unit acquires the predetermined drive time of the moving body having the battery; The moving body is powered by electricity supplied from the battery. When the battery is in a rechargeable state, the charging time scheduling setting unit determines the degree of degradation acceleration of the battery relative to the current SOC and the target SOC based on the degree of degradation acceleration obtained by the degradation acceleration acquisition unit, and sets a charging time schedule that keeps the degree of degradation acceleration of the battery at a low level during the period up to the predetermined drive time.

3. The charging control device according to claim 2, characterized in that, The charging time scheduling setting unit determines the degree of accelerated degradation of the battery relative to the current SOC and current battery temperature, and the degree of accelerated degradation of the battery relative to the target SOC and battery temperature after charging is completed, based on the degree of accelerated degradation obtained by the degree of accelerated degradation acquisition unit, and sets a charging time schedule that keeps the degree of accelerated degradation of the battery at a low level during the period up to the predetermined driving time.

4. The charging control device according to any one of claims 1 to 3, characterized in that, The charging time scheduling setting unit performs the following processing: Whenever the evaluation value acquisition unit acquires the evaluation value at the predetermined time interval, it compares the evaluation value at the current moment with the evaluation value at a moment after the predetermined time. If the evaluation value is low at a time after the specified time, then the time with the low evaluation value is selected. If the evaluation value at a time after the specified time is higher than the evaluation value at the current time, then the current time is set as the charging start time, and the evaluation value acquisition process performed by the evaluation value acquisition unit is stopped.

5. The charging control device according to any one of claims 1 to 3, characterized in that, The charging time scheduling setting unit performs the selection process of the moment with the lowest evaluation value multiple times by making the specified time interval variable.

6. The charging control device according to claim 2, characterized in that, The charging time scheduling setting unit sets the time when the minimum evaluation value among the evaluation values ​​for completing the charging of the battery before the predetermined driving time is set as the charging start time.

7. The charging control device according to claim 2, characterized in that, The evaluation value is the sum of the electricity cost evaluation value, the battery degradation evaluation value, and the charging completion evaluation value, wherein... The electricity cost evaluation value is obtained by multiplying the effective power from the external power source to the battery, the unit price of the electricity cost, and the first weighting coefficient. The battery degradation evaluation value is obtained by multiplying the time integral of the degradation characteristic coefficient by a second weighting coefficient. The degradation characteristic coefficient represents the value of battery degradation during the time period from the last time the mobile body was driven to the predetermined driving time. The charging completion evaluation value is a value that evaluates whether the charging of the battery is completed before the predetermined driving time.

8. The charging control device according to claim 7, characterized in that, When the user of the mobile device prioritizes electricity costs over battery degradation, the first weighting factor is set to be greater than the second weighting factor. When the user prioritizes battery degradation over electricity costs, the second weighting factor is set to be greater than the first weighting factor. If the battery charging is completed before the predetermined driving time, the charging completion evaluation value is set low. If the battery has not been fully charged by the predetermined driving time, the charging completion evaluation value is set high.

9. The charging control device according to claim 7, characterized in that, If the electricity cost for the last battery charge is unchanged from the electricity cost for this battery charge, the charging time scheduling unit uses the electricity cost for the last battery charge to calculate the electricity cost evaluation value.

10. The charging control device according to claim 7, characterized in that, When the user of the mobile device has signed a floating price list contract with variable electricity charges based on daily power supply and demand, the charging time scheduling unit periodically obtains the electricity charges and uses the electricity charges for the corresponding dates to calculate the electricity charge evaluation value.

11. The charging control device according to claim 7, characterized in that, The charging time scheduling setting unit calculates the electricity cost evaluation value by taking into account the temporal changes of the effective power and the unit price of the electricity cost, as well as the first weighting coefficient.

12. The charging control device according to claim 2 or 3, characterized in that, The charging time scheduling unit sets a charging time schedule that completes charging of the battery before a predetermined time of the scheduled driving moment.

13. A mobile body, characterized in that, It includes a battery and a charging control device according to any one of claims 1 to 3.

14. A charging control system, characterized in that, It includes a battery and a charging control device according to any one of claims 1 to 3.

15. A charging control method, wherein the charging control method controls the charging of a battery from an external power source, characterized in that, include: The step of the current SOC acquisition unit acquiring the current SOC of the battery; The step of the target SOC acquisition unit acquiring the target SOC of the battery; The step of the electricity fee acquisition unit to acquire the electricity fee per unit of power from the external power source; The step of obtaining the degree of accelerated degradation of the battery; The step of obtaining an evaluation value is an evaluation of the electricity cost and the degree of accelerated battery degradation when charging the battery from the current SOC to the target SOC. The lower the electricity cost and the lower the degree of accelerated battery degradation, the lower the evaluation value. The charging time scheduling department performs the following steps: Whenever the evaluation value is acquired at a predetermined time interval, the evaluation value at the current moment is compared with the evaluation value at a moment after a predetermined time has elapsed since the current moment, and the lower evaluation value is selected as the first evaluation value. Within a time period from a time before the predetermined time relative to the first evaluation value to a time after the predetermined time relative to the first evaluation value, the evaluation values ​​are sequentially acquired at intervals shorter than the predetermined time. The charging time schedule for the battery is set by setting the time when the lowest evaluation value among the multiple obtained evaluation values ​​is set as the actual start time of charging the battery.

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