JP2021177674A - Vehicle charging system - Google Patents

Abstract

To distribute even an excess of photovoltaic generation power to vehicle charging in addition to commercial power and to implement the stable distribution of the excess in that case.SOLUTION: A vehicle charging system comprises: a charge control master unit 2 which collectively manages commercial power P and photovoltaic generation power; and a plurality of charge control slave units 3 connected for each of chargers 4 and communicating with the charge control master unit 2 to control a current to be supplied to a vehicle 5 by a charger 4 at a connection destination. The charge control master unit 2 includes a second measurement section 22 by which, when excessive power is generated in the photovoltaic generation power to be supplied to a load 9 and an inverse power flow is generated in a commercial power system, such a state is monitored, and notifies the individual charge control slave unit 3 of excessive power information. Upon receiving the notification of the excessive power acquired from the charge control master unit 2, the charge control slave unit 3 controls the current to be supplied to the vehicle 5 by the charger 4 at the connection destination.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicle charging system capable of charging a plurality of vehicles at the same time.

There is a vehicle charging system that can charge a plurality of vehicles equipped with storage batteries such as EV (Electric Vehicle) and PHV (Plug-in Hybrid Vehicle).
For example, in Patent Document 1, while the electric power is managed so as not to exceed the contracted electric power with the electric power supply company, a relatively large current is applied to a vehicle having a large amount of charge for the convenience of the user. It was controlled so that the charging time would not become extremely long.

Japanese Unexamined Patent Publication No. 2013-162555

In the above-mentioned conventional charging system, the priority is set according to the battery capacity of the vehicle, so that the vehicle that requires more charging power can be charged with a higher priority and charged with a larger current, and can charge a plurality of vehicles. It is effective when the above is performed at the same time, and efficient charging can be performed.

However, even for a vehicle that starts charging later, charging is performed under the same conditions as the vehicle that started charging earlier, so that the charging time until full charging may be longer. Considering this amount of charge, for example, if the battery is charged to about 20% of the storage battery capacity, it is possible to travel a certain distance such as returning home, so it is unlikely that the operation will be hindered. Therefore, it is convenient for the user if the charging time to the charge amount that enables traveling a predetermined distance can be shortened even if the time to reach full charge becomes long.

On the other hand, there is a desire for a charging station operator equipped with a photovoltaic power generation facility to use the surplus of the photovoltaic power generation power that has been sold so far for vehicle charging.
However, when supplying the surplus amount of photovoltaic power generation to a vehicle charging system that simultaneously charges the storage batteries of a plurality of electric vehicles, it is difficult to supply without waste. The cause is that the control of allocating the charging power to a plurality of storage batteries (vehicles) needs to be performed by performing mutual communication with the vehicle, and the control takes time. Due to the time required for control, it was difficult to satisfactorily supply the easily variable photovoltaic power generation to the vehicle.

Therefore, in view of such a problem, the present invention provides a vehicle charging system capable of distributing the surplus of the photovoltaic power generation power to the vehicle charging in addition to the commercial power, and at that time, the surplus can be stably distributed. The purpose is to do.

In order to solve the above problems, the invention of claim 1 includes a plurality of chargers for charging a vehicle and a charge control unit for controlling the charging current of the chargers, and includes commercial power and solar power generation power. It is a vehicle charging system that charges the vehicle by means of, and the solar power is supplied to a load different from that of the charger, and when surplus power is generated in the generated power, it is provided for charging the vehicle via the charger. The charge control unit is a charge control master unit that manages the surplus of commercial power and solar power, and a plurality of charge control units that are installed for each charger to control the current supplied to the vehicle by the connected charger. It has a charge control slave unit, and the charge control master unit simultaneously notifies each charge control slave unit of surplus power information when surplus power is generated and a surplus power monitoring unit that monitors the surplus power of solar power generation. On the other hand, the charge control slave unit is provided with a notification unit, and when it receives a notification of surplus power information from the charge control master unit, it has a charge amount up to now, a threshold value which is a required charge amount set at the start of charging, and surplus power information. Based on the above, it is characterized by having a slave unit current control unit that calculates an increase in the charging current by a predetermined calculation and performs current increase control.
According to this configuration, the vehicle is charged by using the surplus of the photovoltaic power generation, so that the photovoltaic power generation power can be effectively utilized. Further, since the distribution of the surplus to each vehicle is determined in consideration of the threshold information, the time required to reach the required charge amount set at the start of charging can be shortened, which is convenient for the user.
Since the distribution of surplus power is determined by each individual charge control slave unit for each vehicle, the amount of calculation of the charge control master unit can be reduced, and stable distribution without waste can be performed against fluctuations in solar power generation. ..

According to the invention of claim 2, in the configuration according to claim 1, the charge control master unit obtains the storage battery remaining amount information and the electric energy cost information of the vehicle to be charged via the charge control slave unit and the charger. It has an acquisition unit and a master unit current control unit that controls the demand value of the received power so as not to exceed the set reference value, and the master unit current control unit is based on the information acquired by the charging vehicle information acquisition unit. In addition, the amount of electric power that enables each vehicle to travel a predetermined distance is calculated, and the amount of charge required until the calculated amount of electric power is reached is set as a threshold value, and the vehicle that has not reached the threshold value is charged. It is characterized in that the current control is performed in preference to the charging of the vehicle that has reached the threshold value.
According to this configuration, vehicle charging by commercial power sets a threshold value for the amount of charge based on the amount of power that enables the vehicle to travel a predetermined distance regardless of the vehicle type and the remaining battery level of the vehicle, and reaches this threshold value. Since charging of a vehicle that does not have a threshold value is prioritized over charging of a vehicle that has reached the threshold value, the time until the threshold value is reached can be shortened, which is convenient for the user. Further, since the mileage of the vehicle whose charge amount has reached the threshold value can be made almost the same regardless of the vehicle type, it is possible to deal equally with the users. And since demand control is also implemented, it is possible to prevent an increase in electricity charges.
The electric power cost is a power consumption rate, and is represented by the number of kilometers traveled per 1 kWh of electric power.

The invention of claim 3 is characterized in that, in the configuration according to claim 2, the slave unit current control unit obtains threshold information from the charge control master unit.
According to this configuration, in addition to the commercial power, the distribution of the surplus solar power is also determined based on the threshold information that enables the vehicle to travel a predetermined distance, so that the threshold is reached regardless of the state of the vehicle. Time can be shortened without fail.

According to the present invention, since the vehicle is charged by using the surplus of the photovoltaic power generation, the photovoltaic power generation power can be effectively utilized. Further, since the distribution of the surplus to each vehicle is determined in consideration of the threshold information, the time required to reach the required charge amount set at the start of charging can be shortened, which is convenient for the user.
Since the distribution of surplus power is determined by each individual charge control slave unit for each vehicle, the amount of calculation of the charge control master unit can be reduced, and stable distribution without waste can be performed against fluctuations in solar power generation. ..

It is a block diagram which shows an example of the vehicle charging system which concerns on this invention. It is a flowchart which shows the flow of the threshold value setting. It is a flowchart which shows the flow of allocating a priority. It is a flowchart which shows the flow of charge control. It is a flowchart which shows the control flow of the charge control master unit when the photovoltaic power generation power is used for vehicle charge. It is a flowchart which shows the control flow of the charge control slave unit when the photovoltaic power generation power is used for vehicle charge.

Hereinafter, embodiments embodying the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an example of a vehicle charging system according to the present invention. In FIG. 1, 2 is a charge control master unit (hereinafter, simply referred to as a “master unit”), and 3 is a charge control slave unit (hereinafter, simply referred to as a “slave unit”). Consists of.
The slave unit 3 is installed for each charger 4 to which the vehicle 5 is connected, the slave unit 3 and the charger 4 are connected by the signal line L1, and the master unit 2 and the slave unit 3 are connected via the signal line L2. And communicate with each other.

On the other hand, the power receiving equipment 7 that supplies power to the load 9 and the charger 4 is connected to the solar power generation equipment 8 in addition to the commercial power P, and the commercial power P supplied at a high voltage is a low voltage at the power receiving equipment 7. Is converted to and supplied to the load 9 and the charger 4 via the power cables L3 and L4, respectively.
The electric power generated by the photovoltaic power generation facility 8 is mainly supplied to the load 9, and when a surplus is generated in the generated electric power, it is supplied to the charger 4 by the control described later. Further, although the master unit 2 and each slave unit 3 are connected by a signal line L2, the signal line L2 may be eliminated and wireless communication may be performed with each other.

The master unit 2 is the first measuring unit 21 that obtains the received power information from the smart meter 10 installed on the service line L5 of the commercial power P, and detects the surplus of the solar power generation power from the reverse power flow to the commercial power system. The second measurement unit 22, the storage unit 23 that stores the demand value, the reference value, the threshold value, the calculation formula, etc., which will be described later, and the communication unit 25 that communicates with each slave unit 3 (first communication unit 25a, second communication unit 25b ... The nth communication unit 25n), the master unit CPU 26 and the like that determine the charging current of the charger 4 and control each unit of the master unit 2 are provided.

In addition to the function of communicating with the slave unit 3, the communication unit 25 has a function of communicating with the vehicle 5 connected to the charger 4 via the slave unit 3, and the vehicle 5 to the vehicle is controlled by the master unit CPU 26. Information on the remaining amount (kWh) of the storage battery mounted on the No. 5 and the electricity cost (the number of kilometers traveled per 1 kWh of electric power) can be obtained.
By the function of the communication unit 25, the master unit CPU 26 calculates the threshold value required for charge control based on the storage battery remaining amount information and the electricity cost information acquired from the vehicle 5.

The slave unit 3 stores a slave unit first communication unit 31 that communicates with the master unit 2, a slave unit second communication unit 32 that communicates with the charger 4, an arithmetic formula for calculating an increase in charging current, and the like. The unit 33 includes a slave unit CPU 34 and the like that control the connected charger 4 and control the slave unit 3.
The slave unit CPU 34 controls the charging current of the charger 4 by receiving the surplus power information of the photovoltaic power generation power notified from the master unit 2. In addition, information on the amount of charge (ascertained from the charging current and charging time) supplied by the charger 4 to the vehicle is transmitted to the master unit 2.

The vehicle charging system configured as described above operates as follows. FIG. 2 is a flowchart for setting the threshold value, which will be described with reference to FIG.
When the master unit CPU 26 acquires the storage battery remaining amount and the electricity cost information from the vehicle 5 via the charge control slave unit 3 and the charger 4 (S11), the amount of electric power that enables the vehicle to travel a predetermined distance based on the acquired information. Is calculated, and the required charge amount is calculated based on the storage battery remaining amount information (S12).
The amount of charge required to enable traveling a predetermined distance is calculated by the following formula.
Required charge amount (kWh) = predetermined mileage (km) / electricity cost (km / kWh) -rechargeable battery remaining amount (kWh) ... (Equation 1)

The required charge amount calculated in this way is set to the threshold value (S13).
As described above, the threshold value is the amount of charge required to travel a predetermined distance regardless of the vehicle type.
The predetermined distance is set as a distance (for example, 50 km) that allows the vehicle to travel to the home or the next charging station.

When the threshold value is set, the priority of charging is assigned next, and then the charging control of each vehicle 5 is performed. Priority allocation is performed as follows.
FIG. 3 is a flowchart showing a flow of assigning priorities, which will be described with reference to FIG. The master unit CPU 26 starts charging when the vehicle 5 is connected to the charger 4 (the charging plug of the vehicle 5 is connected) and the threshold value is set. At the same time, the priority is assigned together with the other vehicles 5 that have already performed charge control.

First, the number of vehicles 5 whose charge amount is less than the threshold value (number of unachieved: n) is grasped (S21), and then the number of vehicles 5 whose charge is more than the threshold value (number of achievements: m) is grasped (s). S22).
The master unit CPU 26 obtains and grasps the charge amount information from the slave unit 3 after starting charging of each vehicle 5, and compares and determines this value with the threshold value.

Next, the vehicles 5 included in the unachieved number n are arranged in descending order of the amount of charge, ranked from the first to the nth and allocated (S23), and the vehicles 5 included in the achieved number m are arranged in descending order of the amount of charge. They are arranged side by side and ranked and allocated from the n + 1st to the n + mth (S24). In this way, the order is made from the first to the n + m number.
At this time, the 1st to nth vehicles 5 have the highest charge amount of the 1st vehicle 5 and the nth vehicle 5 has the smallest charge, and the n + 1st vehicle 5 among the n + 1 to n + mth vehicles 5 has the smallest charge. The charge amount of the vehicle 5 is the largest, and the charge amount of the n + mth vehicle 5 is the smallest. After allocating the priority in this way, the process proceeds to control the increase / decrease of the current.

FIG. 4 shows a flowchart showing a flow of current increase / decrease control for each ordered vehicle 5, and charging control will be described with reference to this flow. This control is also performed by the master unit 2, and the control changes greatly depending on whether the current received power is relative to the reference value.
The reference value is, for example, a power value that is 10% smaller than the maximum demand value, and indicates a value set by the consumer in order to reduce the maximum demand value and reduce the contract fee.

Hereinafter, a case where the judgment standard of deviation information is a reference value will be described. Upon receiving the priority allocation (S31) information, if the deviation information is equal to 0 (goes to the left in S32), that is, if the current received power is approximately equal to the reference value, the charging current of any vehicle 5 is It ends without any change, returns to S31 which is the first step, and the priority is assigned. The current received power is the value of the received power obtained from the smart meter 10 by the first measuring unit 21.
However, the deviation information is a value defined as in Equation 2 of the following equation.
Deviation information (kW) = current received power (kW) -reference value (kW) ... (Equation 2)

Next, when the deviation information is a positive value (goes down in S32), that is, when the received power exceeds the reference value, the control for reducing the current is executed. To be precise, when the average power for 30 minutes is calculated from the current received power and predicted, and when it is determined that the reference value may be exceeded, the control for reducing the current is implemented.
Specifically, the excess current value (deviation value) is calculated by the following equation 3 (S33), and the charging current reduction control (S34) is executed in order from the vehicle 5 that reaches the threshold value and has the smallest charge amount. ..
Deviation value = deviation information (kW) / voltage (V) ... (Equation 3)

However, the maximum reduction amount per vehicle shall be the value obtained by subtracting the predetermined minimum current value from the current current value or the smaller of the calculated deviation values (S35). For example, if the deviation value is 10 amperes and the value obtained by subtracting the predetermined minimum current value from the current current value is 5 amperes, 5 amperes is selected, and the charging current of the n + mth vehicle 5 having the largest charge is selected. Control to reduce 5 amps is implemented. In this way, the vehicle 5 having the smallest charge amount among the threshold values is the highest priority target for reducing the charging current. In other words, charging has the lowest priority.

Then, the current value obtained by subtracting the reduced current value from the deviation value is set as a new deviation value (S36), and the steps S34 to S37 are repeated until the deviation value becomes 0 or for all the vehicles 5 to be charged. Control is performed in the order of vehicles in the set order. In this way, the newly set charging current value is notified from the communication unit 25 to the individual chargers 3 via the slave unit 3 (S43), and the control of S31 to S43 is repeated at predetermined time intervals such as 1 second. Will be implemented.
As a result, when the power received from the commercial power P is reduced, the charging current is reduced from the vehicle 5 that has reached the threshold value. Then, at that time, the charging current is reduced from the vehicle 5 having the least charge amount. Therefore, the charge amount of the vehicle 5 which started charging later does not exceed the charge amount of the vehicle 5 which started charging earlier, and the user who has a long charging time does not feel dissatisfied.

On the other hand, when the deviation information is negative, that is, when the received power does not reach the reference value, control for increasing the charging current is performed.
Specifically, the current value (margin value) that can be increased is calculated by the following equation 4 (S38), and the charging current is increased in the order of the vehicle 5 having the largest charge amount to the vehicle 5 having the smallest charge amount among the vehicles 5 that do not meet the threshold value. (S39).
Margin value = − Deviation information (kW) / Voltage (V) ・ ・ ・ (Equation 4)

However, the maximum amount of increase per vehicle shall be the value obtained by subtracting the current current value from the predetermined maximum charging current value or the smaller of the calculated margin values (S40). For example, if the maximum charge current value minus the current current value is 5 amperes and the margin value is 10 amperes, then 5 amperes is selected and the charge current of the first vehicle 5 with the least charge is 5 amperes. Control to increase amperage is implemented. In this way, the vehicle 5 having the largest amount of charge among the vehicles 5 that has not reached the threshold value becomes the highest priority target for increasing the charging current, and the current increase is performed.

Then, the current value obtained by subtracting the increased current value from the margin value is set as a new margin value (S41), and the steps S39 to S42 are repeated until the margin value becomes 0 or for all the vehicles 5 to be charged. , Control is performed in the order of vehicles in the set order. In this way, the newly set charging current value is notified to the individual chargers 4 (S43), and charging is controlled.

As described above, in the vehicle charging by commercial power, the threshold value of the charge amount is set based on the power amount that enables the vehicle to travel a predetermined distance regardless of the vehicle type and the remaining battery level of the vehicle 5, and the threshold value is not reached. Since the charging of the vehicle 5 is prioritized over the charging of the vehicle 5 that has reached the threshold value, the time until the threshold value is reached can be shortened, which is convenient for the user. Further, since the mileage of the vehicle 5 whose charge amount has reached the threshold value can be made substantially the same regardless of the vehicle type, it is possible to deal equally with the users. And since demand control is also implemented, it is possible to prevent an increase in electricity charges.

When reducing the power received from the commercial power P, the charging current is reduced from the vehicle 5 which has reached the threshold value, and when increasing the power received from the commercial power P, the vehicle whose charge amount is below the threshold value. The charging current is increased from 5.

Next, vehicle charging control will be described when a surplus is generated in the photovoltaic power generation in a state where the vehicle is charged by commercial power.
FIG. 5 is a flowchart showing the control flow of the master unit 2 when the photovoltaic power generation power is used for vehicle charging, and FIG. 6 is a control flow of the slave unit 3 when the photovoltaic power generation power is used for vehicle charging. It is a flowchart which shows, and it will be described with reference to this flow.
When the second measurement unit 22 detects the reverse power flow to the commercial power system, that is, the power sale (S51), and the master unit CPU 26 generates the power sale (Yes in S52), the power sale current from the second measurement unit 22 The value is acquired (S52), and the increase in the charging current to the vehicle 5 in which the power selling current becomes 0 is calculated (S53).
The increase in the charging current is calculated by Equation 5 of the following equation.
Current rise value = (Power selling current value / System margin) / Number of chargers in operation ... (Equation 5)
The calculated current increase value is simultaneously notified to all the operating slave units 3 (S54). The notification of the current increase value is performed at regular time intervals, and "0" is notified if power sales have not occurred (S55).

The system margin is an adjustment value when there are points to be noted depending on the system, and theoretically "1" is desirable, but it is set according to the installation environment of the system such as 0.8. Information on the number of chargers 4 in operation is obtained from the slave unit 3. Further, the electric power supplied from the power receiving equipment 7 to the charger 4 is AC power having a constant voltage such as 200 V, and the current increase value is also the electric power increase value of the same ratio.

On the other hand, each slave unit 3 receives a notification of the current increase value (S61) from the master unit 2, and if the increase value is not 0, the slave unit 3 is in charge (connected to the slave unit 3). Calculate the allocated amount of the charger 4 (Yes in S62). The controlled charging current including the allocated amount is calculated by the following equation 6 based on the notified current increase value (S63). If the notified current increase value is 0, there is no increase in the charging current (No in S62).
Charge current after control (A) = Charge current value before control (A) + Charge current increase value x (1 + (charge amount (Wh) / threshold value (Wh))) x coefficient ... (Equation 6)
The "coefficient" is a coefficient for calculating the amount of current that minimizes the increase value of the charging current regardless of the priority of charging, for example, 0.5, and the "threshold value" is the master unit. Obtained from 2. Further, the "charge amount" is the charge power amount up to the present calculated by the slave unit 3 from the charge current and the charge time of the charger 4 as described above, and the "charge amount / threshold value" has a result larger than 1. If it becomes 0, the priority is lowered by setting it to 0.
The slave unit 3 controls the charger 4 to charge with the current value calculated in this way (S64).

In this way, since the vehicle is charged by using the surplus of the photovoltaic power generation, the photovoltaic power generation power can be effectively utilized. Further, since the distribution of the surplus to each vehicle 5 is calculated based on the charge amount up to the present, the threshold value which is the required charge amount set at the start of charging, and the notified surplus power information, charging starts. It is convenient for the user because it is possible to shorten the time required to reach the amount of charge required to travel a predetermined distance set at times.
Further, since the distribution of the surplus power is determined by the individual charge control slave unit 3 for each vehicle 5, the calculation amount of the charge control master unit 2 can be reduced, which is wasteful for the easily fluctuating photovoltaic power generation. It is possible to carry out stable distribution.

1 ... Vehicle charging system, 2 ... Charging control master unit, 3 ... Charging control slave unit, 4 ... Charger, 5 ... Vehicle, 7 ... Power receiving equipment, 8 ... Solar power generation equipment, 9 ...・ Load, 10 ・ ・ Smart meter, 10 ・ ・ Smart meter (electric energy meter), 21 ・ ・ 1st measurement unit, 22 ・ ・ 2nd measurement unit (surplus power monitoring unit), 23 ・ ・ Storage unit, 25 ・-Communication unit (charging vehicle information acquisition unit, notification unit), 26 ... Master unit CPU (master unit current control unit), 33 ... Slave unit CPU (slave unit current control unit), P ... Commercial power.

Claims (3)

A vehicle charging system that has a plurality of chargers for charging a vehicle and a charge control unit that controls the charging current of the charger, and charges the vehicle using commercial power and photovoltaic power generation.
The photovoltaic power generation is supplied to a load different from that of the charger, and when surplus power is generated in the generated power, it is provided for charging the vehicle via the charger.
The charge control unit includes a charge control master unit that manages surplus commercial power and photovoltaic power generation.
Each of the chargers has a plurality of charge control slave units that are installed and control the current supplied to the vehicle by the connected charger.
The charge control master unit includes a surplus power monitoring unit that monitors the surplus power of photovoltaic power generation, and a surplus power monitoring unit.
When the surplus power is generated, each charge control slave unit is provided with a notification unit for simultaneously notifying the surplus power information.
When the charge control slave unit receives the notification of the surplus power information from the charge control master unit, the charge control slave unit is based on the charge amount up to the present, the threshold value which is the required charge amount set at the start of charging, and the surplus power information. , A vehicle charging system characterized by having a slave unit current control unit that calculates an increase in charging current by a predetermined calculation and performs current increase control. The charge control master unit includes a charging vehicle information acquisition unit that obtains storage battery remaining amount information and electricity cost information of a vehicle to be charged via the charge control slave unit and the charger.
It has a master unit current control unit that controls the demand value of the received power so that it does not exceed the set reference value.
The master unit current control unit calculates the amount of electric power that enables each vehicle to travel a predetermined distance based on the information obtained by the charging vehicle information acquisition unit, and also calculates the amount of electric power that enables the vehicle to travel a predetermined distance.
The feature is that the amount of charge required until the calculated electric energy is reached is set to the threshold value, and current control is performed in which the charge of the vehicle that does not reach the threshold value is prioritized over the charge of the vehicle that has reached the threshold value. The vehicle charging system according to claim 1. The vehicle charging system according to claim 2, wherein the slave unit current control unit obtains the threshold information from the charge control master unit.

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