Charging plan preparation system and charging plan preparation method

Abstract

The present invention provides a charging plan preparation system for preparing a charging plan which can abide by contracted power and reduce power costs, and which can satisfy a target charging completion time and a target accumulated power quantity to the greatest extent possible. A charging plan preparation system (20) according to the present invention comprises: a power usage quantity computation unit (44) that calculates the power cost and the excess power quantity from a contracted power quantity if an electric vehicle (33) were charged from an accumulated power quantity at the current time to a target accumulated power quantity; a penalty computation unit (45) that calculates an accumulated power quantity differential (ΔSOC), which is the differential between the target accumulated power quantity and the accumulated power quantity of the electric vehicle (33), at each time during charging if the electric vehicle (33) were charged to the target accumulated power quantity, and that calculates a penalty in the charging period using the accumulated power quantity differentials; and a charging plan computation unit (48) that calculates a charging plan for the electric vehicle (33) using the excess power quantity, the power cost, and the accumulated power quantity differentials.

Description

Charging planning system and charging planning method

[0001] The present invention relates to a system and a method for formulating a charging plan for a storage battery.

[0002] In recent years, electric vehicles equipped with a storage battery and a motor, such as electric vehicles, plug-in hybrid vehicles, and electric motorcycles, have become widespread. In business establishments and the like that use these vehicles, since a large number of electric vehicles are charged simultaneously or sequentially, there is a risk that the total power demand including that of other power load devices will exceed the contracted power agreed with the power company. There is also a demand to reduce power costs such as electricity charges as much as possible in consideration of the difference in electricity rates between daytime and nighttime and the use of renewable energy such as solar power generation and wind power generation. Furthermore, when considering the operation of an electric vehicle, it is necessary to perform charging such that the target state of charge is achieved by the target charging completion time.

[0003] A conventional technique for a charging planning system for a storage battery mounted on a mobile body is described, for example, in Patent Document 1. In the charging planning system described in Patent Document 1, in a facility provided with a charger for charging a storage battery mounted on a mobile body, it is possible to suppress the amount of power received from the grid by the facility and ensure that the electric vehicle can be reliably used by the scheduled departure time.

[0004] International Publication No. 2013 / 160940

[0005] In the conventional technology, when the target charging completion time (for example, the scheduled departure time of the electric vehicle) and the target state of charge are strictly adhered to, depending on the amount of power to be charged and the constraints of the charging equipment, it may not be possible to satisfy both of these requirements, and there is a risk that a charging plan cannot be formulated. Therefore, even if it is difficult to satisfy both the target charging completion time and the target state of charge, there is a demand for a charging plan that can satisfy these requirements as much as possible.

[0006] In addition, charging plans are also required to keep power consumption below the contracted power to comply with the contracted power, and to reduce power costs such as electricity charges as much as possible.

[0007] The objective of the present invention is to provide a charging plan planning system and charging plan planning method that can formulate a charging plan that can adhere to contracted power, reduce electricity costs, and meet the target charging completion time and target storage amount as closely as possible.

[0008] The charging plan planning system according to the present invention comprises: a power consumption calculation unit that calculates the electricity charges and the amount of excess power from the contracted power amount when charging an electric vehicle from the current amount of stored power to a target amount of stored power; a penalty calculation unit that calculates the difference in stored power, which is the difference between the target amount of stored power and the amount of stored power of the electric vehicle, for each time during charging and calculates a penalty during the charging period using the amount of stored power difference; and a charging plan calculation unit that calculates a charging plan for the electric vehicle using the excess power, the electricity charges and the amount of stored power difference.

[0009] The charging plan planning method according to the present invention is executed on a charging plan planning system comprising a power consumption calculation unit, a penalty calculation unit, and a charging plan calculation unit, and includes a power consumption calculation step in which the power consumption calculation unit calculates the electricity charges and the excess power amount from the contracted power amount when charging an electric vehicle from the current amount of stored power to a target amount of stored power; a penalty calculation step in which the penalty calculation unit calculates the difference in stored power, which is the difference between the target amount of stored power and the amount of stored power of the electric vehicle, for each time during charging and calculates a penalty during the charging period using the difference in stored power; and a charging plan calculation step in which the charging plan calculation unit calculates a charging plan for the electric vehicle using the excess power amount, the electricity charges, and the difference in stored power.

[0010] According to the present invention, it is possible to provide a charging plan planning system and charging plan planning method that can formulate a charging plan that can adhere to the contracted power, reduce electricity costs, and meet the target charging completion time and target storage amount as much as possible.

[0011] A diagram showing an example of the hardware configuration of the charging plan planning system according to Embodiment 1 of the present invention. A block diagram showing an example of the configuration of the charging plan planning system according to this embodiment, which is implemented by software. A diagram showing an example of the screen configuration for setting the charging plan planning period. A diagram showing an example of the screen configuration for setting the operation plan of an electric vehicle. A diagram showing an example of the screen configuration for setting the contracted power amount. A diagram showing an example of the screen configuration for setting the electricity charge. A diagram showing an example of the screen configuration for setting the predicted power generation amount of renewable energy. A diagram showing an example of the screen configuration for setting predicted power demand other than charging. A diagram showing an example of the detailed configuration of the processing unit. An example of a flowchart showing the processing performed by the processing unit. A diagram schematically showing an example of the method for calculating the penalty in the case of a charging delay, and schematically showing an example of the charging plan assumed by the penalty calculation unit, the target charging completion time, and the target amount of stored energy (target SOC). A diagram schematically showing an example of the method for calculating the penalty in the case of a charging delay, and schematically showing an example of the penalty standard (ΔSOC) calculated by the penalty calculation unit. This diagram schematically illustrates an example of how to calculate a penalty in the case of a late charge, and schematically shows an example of the discount rate set by the penalty calculation unit. This diagram schematically illustrates how to calculate a penalty in the case of a late charge, and schematically shows an example of ΔSOC (ΔSOCc) converted using the discount rate calculated by the penalty calculation unit. This diagram shows an example of a charging plan displayed by the charging plan display unit. This diagram schematically illustrates how to calculate a penalty in the case of early charging, and schematically shows an example of the charging plan assumed by the penalty calculation unit, the target charging completion time, and the target amount of stored energy (target SOC). This diagram schematically illustrates how to calculate a penalty in the case of early charging, and schematically shows an example of the penalty standard (ΔSOC) calculated by the penalty calculation unit. This diagram schematically illustrates how to calculate a penalty in the case of early charging, and schematically shows an example of the discount rate set by the penalty calculation unit. This diagram schematically illustrates an example of how to calculate the penalty in the case of premature charging, and schematically shows an example of ΔSOC (ΔSOCc) converted using the discount rate calculated by the penalty calculation unit. This diagram schematically illustrates an example of how to calculate the penalty when formulating a smoothing charge plan for multiple electric vehicles.

[0012] The charging plan planning system and charging plan planning method according to the present invention plan the charging of a storage battery, such as a storage battery installed in an electric vehicle such as an electric car, thereby adhering to the contracted power of the business premises, reducing electricity costs, and meeting the target charging completion time and target storage amount as closely as possible. The target charging completion time is the target time for completing charging, for example, the scheduled departure time of the electric vehicle to be charged. Adhering to the contracted power means keeping the amount of electricity consumed at the business premises below the amount of electricity used that the business premises have contracted with the power company for.

[0013] Hereinafter, a charging plan planning system and a charging plan planning method according to embodiments of the present invention will be described with reference to the drawings. The charging plan planning method according to embodiments of the present invention can be performed by the charging plan planning system according to embodiments of the present invention. In the drawings referenced herein, the same or corresponding components are denoted by the same reference numerals, and repeated descriptions of these components may be omitted.

[0014] The embodiments described below primarily focus on devices and equipment related to charging.

[0015] A charging plan planning system according to Embodiment 1 of the present invention will now be described. As an example, this charging plan planning system plans a charging schedule for an electric vehicle parked in a parking lot, using a charger provided in the parking lot. This parking lot is assumed to be located in a business establishment that operates multiple electric vehicles, such as a transportation company or factory.

[0016] Figure 1 shows an example of the hardware configuration of a charging planning system according to Embodiment 1 of the present invention. In Figure 1, thin lines represent communication lines, and thick lines represent power lines.

[0017] The charging plan planning system 20 according to this embodiment comprises a planning device 1, a network 2, and a business office 3.

[0018] The planning device 1 comprises a CPU (Central Processing Unit) 11, memory 12, storage unit 13, input / output unit 14, and communication unit 15. The input / output unit 14 includes, for example, input devices such as a keyboard or mouse, and output devices such as a display.

[0019] Network 2 is comprised of, for example, the Internet.

[0020] Business premises 3 includes a power receiving panel 31, multiple chargers 32, multiple electric vehicles 33, a power demand unit 34 for purposes other than charging, and an operation unit 35. In addition, renewable energy power generation equipment 36 is installed inside business premises 3. Figure 1 shows, as an example, three chargers 32 and three electric vehicles 33.

[0021] The power receiving panel 31 receives electricity supplied by the power company 4.

[0022] The charger 32 charges the electric vehicle 33 with power supplied from the power receiving panel 31. The charger 32 is controlled by a control device (not shown) installed at the business premises 3 to charge the electric vehicle 33.

[0023] The electric vehicle 33 is equipped with a charging PCS (power conditioner, power converter) 331 and a storage battery 332.

[0024] The planning device 1 is connected to the power receiving panel 31, charger 32, storage battery 332, and operation unit 35 of the business premises 3 via wired or wireless communication through the network 2.

[0025] The electric vehicle 33, which is equipped with a storage battery 332, is connected to the charger 32 and the power line 5 via the charging PCS 331.

[0026] The electricity supplied from the renewable energy power generation equipment 36 installed inside the business premises 3 is supplied to the power line 5 via the power receiving panel 31.

[0027] The electricity supplied by the power company 4 is delivered to the charger 32, the power demand unit 34 (other than charging), and the operation unit 35 through the power receiving panel 31 and power lines 5 inside the business premises 3.

[0028] Figure 2 is a block diagram showing an example of the configuration of the charging plan planning system 20 according to this embodiment, which is implemented by software. The configuration shown in Figure 2 is mainly provided by the planning device 1.

[0029] The software that implements the configuration of the charging plan planning system 20 is stored in the memory unit 13 (Figure 1), and the CPU 11 reads this software from the memory unit 13 and executes it, thereby enabling the charging plan planning system 20 to function.

[0030] The charging plan planning system 20 is a system that plans the charging plan for the electric vehicle 33 (Figure 1), or more precisely, the charging plan for the battery 332 installed in the electric vehicle 33.

[0031] The charging plan planning system 20 includes an input unit 21, a processing unit 22, a charging plan data storage unit 23, a charging plan display unit 24, and a charging plan output unit 25.

[0032] The input unit 21 inputs various data necessary for formulating a charging plan. For example, the input unit 21 inputs various data such as the charging plan formulation period, the operation plan for the electric vehicle 33, the initial charge amount of the electric vehicle 33, electricity charges, the predicted amount of renewable energy generation, and the predicted electricity demand other than charging.

[0033] The planning period for charging includes the start and end dates and times of the planning period, as well as the time intervals within the planning period.

[0034] Figure 3 shows an example of a screen configuration for setting the charging plan planning period. The input / output unit 14 (Figure 1) of the planning device 1 can display a screen as shown in Figure 3.

[0035] The user sets the charging plan period by selecting the start and end dates and times, as well as the time intervals within the planning period, from a pull-down list or by entering them directly.

[0036] Let's return to the explanation of the data acquired by the input unit 21 (Figure 2).

[0037] The operation plan for the electric vehicle 33 includes the departure date and time (target charging completion time) and arrival date and time of the electric vehicle 33, as well as the amount of charge stored at departure (target amount of charge) and the amount of charge stored at arrival of the electric vehicle 33.

[0038] Figure 4 shows an example of a screen configuration for setting the operation plan for the electric vehicle 33. The input / output unit 14 (Figure 1) of the planning device 1 can display a screen as shown in Figure 4.

[0039] The user sets an operation plan for the electric vehicle 33 by selecting or directly inputting the charge start date / time and the stored power amount at that time, as well as the charge completion date / time and the stored power amount at that time, from a pull-down list.

[0040] Returning to the description of data acquired by the input unit 21 (FIG. 2).

[0041] The initial stored power amount of the electric vehicle 33 is the current value of the stored power amount of the electric vehicle 33 when the electric vehicle 33 is connected to the charger 32 at the start of the planning period.

[0042] The electricity rate includes contracted power amount (the amount of power used that the business site 3 has contracted for with the electric power company 4), and electricity rates for different time periods such as daytime and nighttime.

[0043] FIG. 5 is a diagram showing an example of a screen configuration for setting a contracted power amount.

[0044] The user sets the contracted power amount by selecting it from a pull-down list or directly inputting it.

[0045] FIG. 6 is a diagram showing an example of a screen configuration for setting an electricity rate.

[0046] The user sets the electricity rate by selecting or directly inputting settings for days of the week such as weekdays, Saturdays, and Sundays / public holidays, settings for time periods such as daytime and nighttime, and the electricity rate per kWh for the set time period, from a pull-down list.

[0047] Returning to the description of data acquired by the input unit 21 (FIG. 2).

[0048] The predicted power generation amount of renewable energy includes the predicted power generation amount of renewable energy such as solar power generation and wind power generation and the electricity rate for each time interval of the planning period within the planning period. That is, the predicted power generation amount of renewable energy includes temporal changes in the predicted power generation amount of renewable energy and the electricity rate over the planning period.

[0049] In this embodiment, the predicted amount of renewable energy generated is the predicted amount of renewable energy generated by the renewable energy power generation equipment 36 installed inside the business premises 3. However, if renewable energy generated outside the business premises 3 is supplied through the power line 5, or if renewable energy supplied by other businesses is purchased, a predicted amount of renewable energy can also be set for such renewable energy.

[0050] Figure 7 shows an example of a screen configuration for setting the predicted power generation amount for renewable energy.

[0051] During the planning period, users can set predicted renewable energy generation amounts by directly inputting the amount of electricity generated at each time interval within the planning period, or by importing text files, CSV files, etc.

[0052] Let's return to the explanation of the data acquired by the input unit 21 (Figure 2).

[0053] The predicted electricity demand other than charging includes the predicted electricity demand at business establishment 3 for each time interval during the planning period, excluding the electricity demand for charging the electric vehicle 33. In other words, the predicted electricity demand other than charging includes the change over time during the planning period of the predicted electricity demand at business establishment 3 for electric vehicle 33, excluding the electricity demand for charging the electric vehicle 33. The electricity demand other than charging the electric vehicle 33 includes the electricity consumed for lighting and air conditioning at business establishment 3, and, if business establishment 3 is a factory, the electricity consumed by factory equipment.

[0054] Figure 8 shows an example of a screen configuration for setting predicted power demand other than charging.

[0055] During the planning period, users can set predicted power demand other than charging by directly inputting the power demand for each time interval within the planning period, or by importing text files, CSV files, etc.

[0056] Returning to the explanation of the charging plan planning system 20 shown in Figure 2.

[0057] The processing unit 22 acquires various data input by the input unit 21 and formulates a charging plan based on this data. The processing unit 22 formulates a charging plan that minimizes the value of the objective function, which will be described later.

[0058] The charging plan includes the time of charging completion, changes in the amount of stored energy over time, changes in the amount of charge (power consumption) over time, and changes in electricity charges over time. Here, "change over time" means that the values ​​are calculated over the time intervals of the planning period.

[0059] The charging plan data storage unit 23 stores the charging plan devised by the processing unit 22.

[0060] The charging plan display unit 24 displays the charging plan devised by the processing unit 22, or the charging plan stored by the charging plan data storage unit 23, on the display of the input / output unit 14 (Figure 1) or the like.

[0061] The charging plan output unit 25 outputs the charging plan devised by the processing unit 22, or the charging plan stored in the charging plan data storage unit 23, to a control device that controls the charger 32 (Figure 1). This control device controls the charger 32 based on the charging plan and charges the battery 332 of the electric vehicle 33.

[0062] The charging planning system 20 operates periodically, for example, at intervals of 30 minutes, 1 hour, or 1 day. Alternatively, the charging planning system 20 may operate when a specific event occurs. These specific events include, for example, the electric vehicle 33 being connected to the charger 32, and the electric vehicle 33 being disconnected from the charger 32.

[0063] Figure 9 shows an example of the detailed configuration of the processing unit 22.

[0064] The processing unit 22 includes a power storage amount measurement unit 41, a target power storage amount setting unit 42, a target charging completion time setting unit 43, a power consumption calculation unit 44, a penalty calculation unit 45, a constraint condition setting unit 46, an objective function setting unit 47, and a charging plan calculation unit 48.

[0065] The energy storage amount measurement unit 41, when the electric vehicle 33 is connected to the charger 32, obtains the current energy storage amount of the electric vehicle 33 at the start of the charging plan planning period via the communication line from the electric vehicle 33. The energy storage amount obtained by the energy storage amount measurement unit 41 is the remaining charge (SOC, State of Charge) of the electric vehicle 33 at the current time.

[0066] The target energy storage amount setting unit 42 obtains the target energy storage amount of the electric vehicle 33 from the input unit 21.

[0067] The target charging completion time setting unit 43 obtains the target charging completion time for the electric vehicle 33 from the input unit 21.

[0068] The power consumption calculation unit 44 calculates the electricity cost for charging the electric vehicle 33 from its current charge level to its target charge level. The current charge level of the electric vehicle 33 is obtained by the charge level measurement unit 41. The target charge level of the electric vehicle 33 is obtained by the target charge level setting unit 42. Furthermore, the power consumption calculation unit 44 calculates the excess power consumption from the contracted power level when charging the electric vehicle 33 from its current charge level to its target charge level. The contracted power level is obtained by the input unit 21 (Figure 2).

[0069] The penalty calculation unit 45 calculates the penalty for the charging period from the start of charging to the completion of charging using the method described later. In this embodiment, the penalty is a value obtained by integrating over time the value obtained by multiplying the difference between the target amount of stored energy and the amount of stored energy at each time during charging (referred to as the difference in stored energy or penalty criterion, as described later) by a discount rate. The discount rate is a value (or coefficient) set for each time during charging according to the time difference from the target charging completion time. The amount of stored energy at each time during charging is a value obtained based on the increase in the amount of stored energy due to charging in the charging plan assumed by the penalty calculation unit 45. Furthermore, each time during charging is a time determined by the time interval of the planning period described above.

[0070] The constraint setting unit 46 sets constraints such as the contracted power amount of the business establishment 3 with the power company 4, the maximum output of the charger 32, and the maximum number of electric vehicles 33 that can be connected to multiple chargers 32 (i.e., that can be charged by multiple chargers 32). These constraints may include conditions defined by the specifications of the equipment at the business establishment 3.

[0071] The objective function setting unit 47 sets the objective function to be used when formulating a charging plan by optimization calculation. In this embodiment, as an example, the objective function described below is used. For example, the function obtained by multiplying the excess power amount from the contracted power amount by a predetermined weighting coefficient is used as the objective function. Also, the function obtained by multiplying the electricity charge by a predetermined weighting coefficient is used as the objective function. Also, the function obtained by multiplying the excess power amount from the contracted power amount, the electricity charge, and the penalty by a predetermined weighting coefficient, and then taking the sum of these three functions multiplied by the weighting coefficient is used as the objective function.

[0072] The charging plan calculation unit 48 calculates a charging plan using the electricity charges calculated by the power consumption calculation unit 44, the excess power consumption calculated by the power consumption calculation unit 44, and the difference in stored energy (also called the penalty standard), which will be described later. In this embodiment, the charging plan calculation unit 48 calculates a charging plan that minimizes the value of the objective function set by the objective function setting unit 47 under the constraints set by the constraint setting unit 46. The charging plan calculated by the charging plan calculation unit 48 includes the changes over time in the charge amount (power consumption, i.e., the amount of power charged) and stored energy (remaining energy, i.e., SOC) of the battery 332 of the target electric vehicle 33.

[0073] Figure 10 is an example of a flowchart showing the process executed by the processing unit 22.

[0074] In S1, the energy storage measurement unit 41 acquires the current energy storage amount of the electric vehicle 33.

[0075] In S2, the target energy storage amount setting unit 42 acquires the target energy storage amount for the electric vehicle 33.

[0076] In S3, the target charging completion time setting unit 43 acquires the target charging completion time for the electric vehicle 33.

[0077] In S4, the power consumption calculation unit 44 calculates the electricity cost for charging the electric vehicle 33 from its current charge level to a target charge level.

[0078] In S5, the penalty calculation unit 45 calculates the penalty for the period from the start of charging to the completion of charging.

[0079] Here, the details of how the penalty calculation unit 45 calculates the penalty will be explained. The penalty calculation unit 45 assumes a charging plan for the electric vehicle 33 and calculates the penalty for this assumed charging plan. In this charging plan, the amount of stored energy in the electric vehicle 33 increases toward the target amount of stored energy through charging.

[0080] In this embodiment, an example of how the penalty calculation unit 45 calculates a penalty in the case of a "charging delay," that is, when the penalty calculation unit 45 assumes a charging plan in which the time when the electric vehicle 33 is completed to charge is later than the target charging completion time, will be described.

[0081] Figures 11A to 11D schematically show examples of how to calculate penalties in the case of charging delays. In Figures 11A to 11D, the amount of stored charge (remaining charge) of the electric vehicle 33 is represented by State of Charge (SOC).

[0082] Figure 11A schematically shows an example of a charging plan assumed by the penalty calculation unit 45, a target charging completion time, and a target amount of stored energy (target SOC). In the charging plan, the SOC of the electric vehicle 33 (actual SOC) increases over time due to charging. However, even at the target charging completion time, the actual SOC does not reach the target amount of stored energy (target SOC), resulting in a near miss. As more time passes, the actual SOC reaches the target SOC due to charging.

[0083] In the following, the difference between the target amount of stored energy (target SOC) and the amount of stored energy in the electric vehicle 33 (actual SOC) at each time point after the target charging completion time will be called the "penalty criterion" and will be represented by ΔSOC. The penalty criterion is the amount of charge required to reach the target amount of stored energy at each time point. Since the penalty criterion (ΔSOC) is the difference between the target amount of stored energy and the amount of stored energy at each time point, it will also be called the stored energy difference.

[0084] The penalty calculation unit 45 calculates the difference in stored energy (ΔSOC), which is the basis for the penalty, for each time point during charging.

[0085] Figure 11B is a schematic diagram showing an example of a penalty standard (ΔSOC) calculated by the penalty calculation unit 45.

[0086] Next, the penalty calculation unit 45 sets a discount rate for each time after the target charging completion time, according to the time difference from the target charging completion time. In this embodiment, the discount rate is any value greater than 1, and the larger the time difference from the target charging completion time, the larger the value. The discount rate is a coefficient that increases the penalty as the time difference from the target charging completion time increases.

[0087] Figure 11C is a schematic diagram showing an example of a discount rate set by the penalty calculation unit 45.

[0088] Next, the penalty calculation unit 45 multiplies the penalty standard (ΔSOC) by the discount rate to calculate the "ΔSOC converted using the discount rate" for each time point. Hereafter, the ΔSOC converted using the discount rate will be represented as ΔSOCc.

[0089] Figure 11D schematically shows an example of ΔSOC (ΔSOCc) converted using the discount rate, calculated by the penalty calculation unit 45.

[0090] Next, the penalty calculation unit 45 calculates the penalty in the case of charging delay by integrating ΔSOC (ΔSOCc) converted using the discount rate over time as shown in equation (1).

[0091] Penalty = ∫ΔSOCcdt (1) In equation (1), the time integral is the time range in which ΔSOCc exists.

[0092] In this embodiment, the penalty is calculated using the discount-rate converted ΔSOC (ΔSOCc in Figure 11D), which is obtained by multiplying the time-varying penalty criterion ΔSOC (Figure 11B) and the discount rate at each time (Figure 11C). The value of the discount-rate converted ΔSOC (ΔSOCc) is determined by the time difference from the target charging completion time (charging delay time) and the penalty criterion (ΔSOC, stored energy difference).

[0093] In this embodiment, a charging plan is calculated that minimizes the value of the objective function including the penalty obtained from ΔSOC (ΔSOCc) converted using the discount rate. Therefore, a charging plan is formulated that minimizes the charging delay time up to the target amount of stored energy, that is, a charging plan that satisfies the target charging completion time and target amount of stored energy as much as possible.

[0094] Returning to the explanation of the flowchart shown in Figure 10.

[0095] In S6, the constraint setting unit 46 sets the constraint conditions as described above.

[0096] In S7, the objective function setting unit 47 sets the objective function to be used when formulating a charging plan through optimization calculation.

[0097] In this example, the objective function is, as described above, a function f1 obtained by multiplying the excess power amount from the contracted power amount by a weighting coefficient, a function f2 obtained by multiplying the electricity charge by a weighting coefficient, a function f3 obtained by multiplying the penalty by a weighting coefficient, and a function f4 obtained by multiplying the excess power amount from the contracted power amount, the electricity charge, and the penalty by a weighting coefficient, and then taking the sum of these three functions.

[0098] These objective functions f1 to f4 are expressed by equations (2) to (5), with excess energy, electricity charges, and penalties as variables. (2) Objective function f1 = W1 × (Excess energy) (3) Objective function f2 = W2 × (Electricity charges) (4) Objective function f3 = W3 × (Penalty) (5) Objective function f4 = W1 × (Excess energy) + W2 × (Electricity charges) + W3 × (Penalty) (5) In equations (2) to (5), W1, W2, and W3 are weighting coefficients that are arbitrarily determined in advance.

[0099] In S8, the charging plan calculation unit 48 calculates and formulates a charging plan that minimizes the value of the objective function under the set constraints.

[0100] In this embodiment, the charging plan calculation unit 48 calculates the charging plan using one of the following two methods.

[0101] Let's explain one method. The charging plan calculation unit 48 calculates the charging plan by minimizing the value of objective function f1, which has excess energy as a variable, then minimizing the value of objective function f2, which has electricity charges as a variable, and then minimizing the value of objective function f3, which has a penalty as a variable. By minimizing the value of objective function f1, which has excess energy as a variable, the contracted power can be maintained. Next, by minimizing the value of objective function f2, which has electricity charges as a variable, electricity costs can be reduced while maintaining the contracted power. Finally, by minimizing the value of objective function f3, which has a penalty as a variable, the target charging completion time and target stored energy can be met as much as possible while maintaining the contracted power and reducing electricity costs.

[0102] The other method will now be described. The charging plan calculation unit 48 calculates a charging plan by minimizing the value of an objective function f4, which is the sum of excess energy, electricity charges, and penalties. By minimizing the value of the objective function f4, which has excess energy, electricity charges, and penalties as variables, it is possible to maintain the contracted power and reduce electricity costs, and to satisfy the target charging completion time and target stored energy as much as possible. In this method, it is preferable to adjust the magnitudes of the weighting coefficients W1, W2, and W3 used in the objective function f4 according to the priority of which of the excess energy, electricity charges, and penalties to minimize first.

[0103] In S9, the charging plan calculation unit 48 outputs the devised charging plan to the charging plan data storage unit 23, the charging plan display unit 24, and the charging plan output unit 25. The charging plan data storage unit 23 stores the charging plan. The charging plan display unit 24 displays the charging plan on the display of the input / output unit 14 (Figure 1). The charging plan output unit 25 outputs the charging plan to a control device that controls the charger 32 (Figure 1).

[0104] Figure 12 shows an example of a charging plan displayed by the charging plan display unit 24. As an example, Figure 12 shows the charging plans for each of the three electric vehicles 33 (EV1 to EV3).

[0105] The first charging of the three electric vehicles 33 will be performed between time 0 and time 23, and then the three electric vehicles 33 will be driven and discharged at time 24. Furthermore, the third electric vehicle 33 will be charged a second time between time 24 and time 47, and then the three electric vehicles 33 will be driven and discharged at time 48. The target charging completion time for the three electric vehicles 33 is set to time 12 for the first charge and time 36 for the second charge. The target storage capacity is set to 20kWh for both the first and second charges for EV1, 10kWh for the first charge and 15kWh for the second charge for EV2, and 10kWh for both the first and second charges for EV3.

[0106] During the first charging attempt, all three electric vehicles 33 completed charging later than the target charging completion time. This indicates that, under the conditions of the first charging attempt, it was not possible to meet the target charging completion time due to equipment limitations and other factors.

[0107] If we were to impose a constraint that the target charging completion time must be strictly adhered to, then it would be impossible to formulate a charging plan at all, resulting in no solution.

[0108] In this embodiment, it is possible to formulate a charging plan that minimizes charging delays, while allowing for charging to be completed later than the target charging completion time.

[0109] In the example shown in Figure 12, the charging plan for the second charge is designed so that EV1 and EV3 meet the target charging completion time, while only EV2 experiences a charging delay.

[0110] According to this embodiment, it is possible to formulate a charging plan that adheres to the contracted power and reduces electricity costs, while meeting the target charging completion time and target storage amount as closely as possible. For example, in this embodiment, even if charging is completed later than the target charging completion time, it is possible to formulate a charging plan that meets the target storage amount.

[0111] A charging plan planning system according to Embodiment 2 of the present invention will be described. The charging plan planning system according to Embodiment 1 has substantially the same configuration as the charging plan planning system according to Embodiment 1, but the method by which the penalty calculation unit 45 calculates the penalty is different. Below, the differences between the charging plan planning system according to Embodiment 1 and the charging plan planning system according to Embodiment 1 will be mainly described.

[0112] In this embodiment, an example of how the penalty calculation unit 45 calculates a penalty when it assumes a "early charging" scenario, that is, a charging plan in which the time when the electric vehicle 33 is fully charged is earlier than the target charging completion time.

[0113] Figures 13A to 13D schematically show an example of how to calculate the penalty in the case of premature charging.

[0114] Figure 13A schematically shows an example of a charging plan assumed by the penalty calculation unit 45, a target charging completion time, and a target amount of stored energy (target SOC). In the charging plan, the SOC of the electric vehicle 33 (actual SOC) increases over time due to charging. In this embodiment, the actual SOC reaches the target amount of stored energy (target SOC) before reaching the target charging completion time.

[0115] In the following, the difference between the target amount of stored energy (target SOC) and the amount of stored energy in the electric vehicle 33 (actual SOC) at each time point prior to the target charging completion time will be called the "penalty criterion" and will be represented by ΔSOC. The penalty criterion is the amount of charge required to reach the target amount of stored energy at each time point. Since the penalty criterion (ΔSOC) is the difference between the target amount of stored energy and the amount of stored energy at each time point, it will also be called the stored energy difference.

[0116] The penalty calculation unit 45 calculates the difference in stored energy (ΔSOC), which is the basis for the penalty, for each time point during charging.

[0117] Figure 13B is a schematic diagram showing an example of a penalty standard (ΔSOC) calculated by the penalty calculation unit 45.

[0118] Next, the penalty calculation unit 45 sets a discount rate at each time point prior to the target charging completion time, according to the time difference from the target charging completion time. In this embodiment, the discount rate is any value greater than zero and less than one, and the larger the time difference from the target charging completion time, the smaller the value. The discount rate is a coefficient that reduces the penalty as the time difference from the target charging completion time increases.

[0119] Figure 13C is a schematic diagram showing an example of a discount rate set by the penalty calculation unit 45.

[0120] Next, the penalty calculation unit 45 multiplies the penalty standard (ΔSOC) by the discount rate to calculate the "ΔSOC converted using the discount rate" for each time point. Hereafter, the ΔSOC converted using the discount rate will be represented as ΔSOCc.

[0121] Figure 13D schematically shows an example of ΔSOC (ΔSOCc) converted using the discount rate, calculated by the penalty calculation unit 45.

[0122] Next, the penalty calculation unit 45 calculates the penalty in the case of early charging by integrating ΔSOC (ΔSOCc) converted using the discount rate over time as shown in equation (1) in Example 1. In equation (1), the range of time integration is the time range in which ΔSOCc exists.

[0123] In this embodiment, the penalty is calculated using the discount-rate converted ΔSOC (ΔSOCc in Figure 13D), which is obtained by multiplying the time-varying penalty criterion ΔSOC (Figure 13B) and the discount rate at each time (Figure 13C). The value of the discount-rate converted ΔSOC (ΔSOCc) is determined by the time difference from the target charging completion time (the time when charging is earlier) and the penalty criterion (ΔSOC, difference in stored energy).

[0124] In this embodiment, a charging plan is calculated that minimizes the value of the objective function, including the penalty, obtained from ΔSOC (ΔSOCc) converted using the discount rate. Therefore, a charging plan can be devised that completes charging as early as possible relative to the target charging completion time, that is, a charging plan that satisfies the target charging completion time and the target amount of stored energy as much as possible.

[0125] According to this embodiment, it is possible to formulate a charging plan that can adhere to the contracted power, reduce electricity costs, and meet the target charging completion time and target storage amount. For example, in this embodiment, it is possible to formulate a charging plan that can charge to the target storage amount as early as possible before the target charging completion time.

[0126] This section describes a charging plan planning system according to Embodiment 3 of the present invention. The charging plan planning system according to this embodiment has substantially the same configuration as the charging plan planning systems according to Embodiments 1 and 2, but the method by which the penalty calculation unit 45 calculates the penalty is different. Below, the differences between the charging plan planning system according to this embodiment and the charging plan planning systems according to Embodiments 1 and 2 will be mainly described.

[0127] Examples 1 and 2 describe how to plan a charge for one of several electric vehicles 33.

[0128] This embodiment describes an example of formulating a charging plan for multiple electric vehicles 33. Specifically, it describes an example of how the penalty calculation unit 45 calculates a penalty when formulating a charging plan for "smoothing charging," which charges multiple electric vehicles 33 in the same way overall.

[0129] Figure 14 schematically illustrates an example of a penalty calculation method when formulating a smoothing charge plan for multiple electric vehicles 33. As an example, Figure 14 shows a charge plan for two electric vehicles 33 (EV1 and EV2).

[0130] First, the penalty calculation unit 45 assumes and sets up a charging plan for multiple electric vehicles 33. In this charging plan, similar to Examples 1 and 2, the amount of charge stored in the electric vehicles 33 increases toward the target amount of charge through charging.

[0131] Next, the penalty calculation unit 45 calculates the difference in stored energy (ΔSOC), which is the basis for the penalty, for each of the electric vehicles 33 (EV1, EV2).

[0132] Next, the penalty calculation unit 45 determines the maximum and minimum values ​​of the ΔSOC for all electric vehicles 33 (EV1, EV2).

[0133] Next, the penalty calculation unit 45 calculates the difference between the maximum and minimum values, and uses this difference as the penalty in the case of smoothing charge. This penalty is larger the greater the difference in ΔSOC among the multiple electric vehicles 33.

[0134] In this embodiment, the charging plan calculation unit 48 calculates a charging plan that minimizes the value of the objective function, including this penalty. Therefore, in this embodiment, it is possible to devise a charging plan that smoothly charges all electric vehicles 33, in other words, charges each electric vehicle 33 in the same manner.

[0135] Furthermore, the penalty calculation unit 45 may use the maximum value of the ΔSOC of all electric vehicles 33 (EV1, EV2) as the penalty in the case of smoothing charge. The charging plan calculation unit 48 calculates a charging plan that minimizes the value of the objective function including this penalty, and by minimizing the maximum ΔSOC, it can formulate a charging plan that smoothly charges all electric vehicles 33.

[0136] Furthermore, this embodiment may also include the configuration described below.

[0137] The penalty calculation unit 45 calculates for each of the multiple electric vehicles 33, at a time after the target charging completion time, a value obtained by multiplying the difference in stored energy (ΔSOC), which is the basis for the penalty, by a discount rate, and then calculates the first penalty by integrating this value over time. As explained in Example 1, this discount rate is greater than 1 and has a larger value as the time difference from the target charging completion time increases.

[0138] Furthermore, the penalty calculation unit 45 calculates a value for each of the multiple electric vehicles 33 at a time prior to the target charging completion time by multiplying the difference in stored energy (ΔSOC), which is the basis for the penalty, by a discount rate, and then calculates a second penalty by integrating this value over time. As explained in Example 2, this discount rate is greater than zero and less than one, and the larger the time difference from the target charging completion time, the smaller the value.

[0139] Furthermore, the penalty calculation unit 45 calculates the difference in stored energy (ΔSOC), which is the basis for the penalty, for each of the multiple electric vehicles 33 at each time during charging, and sets the maximum value of the difference in stored energy as the third penalty. Alternatively, the penalty calculation unit 45 may calculate the difference in stored energy (ΔSOC), which is the basis for the penalty, for each of the multiple electric vehicles 33 at each time during charging, calculate the difference between the maximum and minimum values ​​of the difference in stored energy, and set this difference as the third penalty.

[0140] The charging plan calculation unit 48 calculates a charging plan by minimizing the value of an objective function obtained by taking the sum of the following variables: excess power multiplied by a first weighting coefficient, electricity charges multiplied by a second weighting coefficient, a first penalty multiplied by a third weighting coefficient, a second penalty multiplied by a fourth weighting coefficient, and a third penalty multiplied by a fifth weighting coefficient. Once the charging plan calculation unit 48 calculates such a charging plan, it can formulate a charging plan that smoothly charges all electric vehicles 33, regardless of whether the charging plan assumed by the penalty calculation unit 45 is a charging delay plan or a charging advance plan.

[0141] According to this embodiment, it is possible to formulate a charging plan that can adhere to the contracted power and reduce electricity costs, satisfy the target charging completion time and target storage amount, and furthermore, to formulate a charging plan that is as smooth as possible among multiple electric vehicles 33.

[0142] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible. For example, the embodiments described above are explained in detail to make the present invention easier to understand, and the present invention is not necessarily limited to embodiments having all of the described configurations. Furthermore, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment. It is also possible to add configurations from other embodiments to the configuration of one embodiment. In addition, it is possible to delete parts of the configuration of each embodiment, or to add or replace other configurations.

[0143] 1...Planning device, 2...Network, 3...Business office, 4...Power company, 5...Power line, 11...CPU, 12...Memory, 13...Storage unit, 14...Input / output unit, 15...Communication unit, 20...Charging plan planning system, 21...Input unit, 22...Processing unit, 23...Charging plan data storage unit, 24...Charging plan display unit, 25...Charging plan output unit, 31...Power receiving board, 32...Charger, 33...Electric vehicle, 34...Power demand unit other than charging, 35...Operation unit, 36...Renewable energy power generation equipment, 41...Storage amount measurement unit, 42...Target storage amount setting unit, 43...Target charging completion time setting unit, 44...Energy usage calculation unit, 45...Penalty calculation unit, 46...Constraint condition setting unit, 47...Objective function setting unit, 48...Charging plan calculation unit, 331...Charging PCS, 332...Storage battery.

Claims

1. A charging plan planning system comprising: a power consumption calculation unit that calculates the electricity charges and the amount of excess power from the contracted power amount when charging an electric vehicle from the current amount of stored power to a target amount of stored power; a penalty calculation unit that calculates the difference in stored power, which is the difference between the target amount of stored power and the amount of stored power of the electric vehicle, for each time during charging, and calculates a penalty during the charging period using the amount of stored power difference; and a charging plan calculation unit that calculates a charging plan for the electric vehicle using the excess power, the electricity charges, and the amount of stored power difference.

2. The charging planning system according to claim 1, wherein the target time for completing the charging of the electric vehicle is defined as the target charging completion time, a value set for each time during charging according to the time difference from the target charging completion time is defined as the discount rate, the penalty calculation unit calculates a value for each time obtained by multiplying the difference in stored energy by the discount rate, and calculates the penalty by integrating the value over time, and the charging plan calculation unit calculates the charging plan by minimizing the value of an objective function with the excess energy as a variable, minimizing the value of an objective function with the electricity charge as a variable, and minimizing the value of an objective function with the penalty as a variable.

3. The charging planning system according to claim 1, wherein the target time for completing the charging of the electric vehicle is defined as the target charging completion time, a value set at each time during charging according to the time difference from the target charging completion time is defined as the discount rate, the penalty calculation unit calculates a value for each time obtained by multiplying the difference in stored energy by the discount rate, and calculates the penalty by integrating the value over time, and the charging plan calculation unit uses the excess energy amount multiplied by a first weighting coefficient, the electricity charge multiplied by a second weighting coefficient, and the penalty multiplied by a third weighting coefficient as variables, and calculates the charging plan by minimizing the value of an objective function obtained by taking the sum of these variables.

4. The charging planning system according to claim 2 or 3, wherein the penalty calculation unit calculates the penalty at a time after the target charging completion time, and the discount rate is greater than 1 and has a larger value as the time difference from the target charging completion time increases.

5. The charging planning system according to claim 2 or 3, wherein the penalty calculation unit calculates the penalty at a time prior to the target charging completion time, and the discount rate is greater than zero and less than one, and the value decreases as the time difference from the target charging completion time increases.

6. The charging planning system according to claim 1, wherein the penalty calculation unit calculates the difference in stored energy for each of the plurality of electric vehicles, and the maximum value of the difference in stored energy is set as the penalty.

7. The charging planning system according to claim 1, wherein the penalty calculation unit calculates the difference in stored energy for each of the plurality of electric vehicles, determines the maximum and minimum values ​​of the difference in stored energy, and sets the difference between the maximum and minimum values ​​as the penalty.

8. The target time for completing the charging of the electric vehicle is defined as the target charging completion time, and the value set at each time during charging according to the time difference from the target charging completion time is defined as the discount rate, the penalty calculation unit calculates for each of the multiple electric vehicles, at a time after the target charging completion time, the value obtained by multiplying the difference in stored energy by the first discount rate, and calculates the first penalty by integrating the value over time, the penalty calculation unit calculates for each of the multiple electric vehicles, at a time before the target charging completion time, the value obtained by multiplying the difference in stored energy by the second discount rate, and calculates the second penalty by integrating the value over time, the penalty calculation unit calculates the difference in stored energy for each of the multiple electric vehicles, and sets the maximum value of the difference in stored energy as the third penalty, or the difference between the maximum and minimum values ​​of the difference in stored energy as the third penalty, The charging plan calculation unit calculates the charging plan by minimizing the value of an objective function obtained by taking the excess power amount multiplied by a first weighting coefficient, the electricity charge multiplied by a second weighting coefficient, the first penalty multiplied by a third weighting coefficient, the second penalty multiplied by a fourth weighting coefficient, and the third penalty multiplied by a fifth weighting coefficient as variables, and taking the sum of these variables as variables.

9. A charging plan planning method, which is executed on a charging plan planning system comprising: an energy consumption calculation unit, a penalty calculation unit, and a charging plan calculation unit, comprising: an energy consumption calculation step in which the energy consumption calculation unit calculates the electricity charges and the excess energy amount from the contracted energy amount when charging an electric vehicle from the current energy amount to a target energy amount; a penalty calculation step in which the penalty calculation unit calculates the energy amount difference, which is the difference between the target energy amount and the energy amount of the electric vehicle, for each time during charging, and calculates a penalty during the charging period using the energy amount difference when charging the electric vehicle to the target energy amount; and a charging plan calculation step in which the charging plan calculation unit calculates a charging plan for the electric vehicle using the excess energy amount, the electricity charges, and the energy amount difference.

Images