JP7115397B2 - Electric vehicle charging system - Google Patents

Description

The present invention relates to a charging system for electric vehicles.

In the power supply device for a cargo handling vehicle disclosed in Patent Document 1, during the break time provided during working hours for cargo handling work using the cargo handling vehicle, the required electric energy is reduced according to the length of the break time. The charging current of the lithium battery is set so that the charging power can be fully charged, and the charging circuit for the lithium battery is used to charge the lithium battery. In addition, when charging the lithium battery during work hours other than break time, the charging current of the lithium battery is set so that it can be charged from the required amount of power to the full charge amount in a predetermined short time. A battery charging circuit is used to rapidly charge a lithium battery.

JP 2014-96874 A

By the way, in the electric vehicle charging system, as shown in FIG. Operation and charging are performed systematically for each vehicle (electric vehicle 1, electric vehicle 2, . . . , electric vehicle N). In this case, the required electric energy, operating time, and charging time differ according to the operation plan of the vehicle. In addition, it is difficult to deal with sudden charging during operating hours. For example, in the configuration of Patent Literature 1, although full charging is not necessary in overtime charging, the battery is charged to full charge within a predetermined time, resulting in excessive charging.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a charging system for an electric vehicle that can perform appropriate charging even if it is not planned.

A charging system for an electric vehicle for solving the above problems includes a plurality of charging devices for charging batteries of the electric vehicle, a charging control device for controlling the charging devices, an operation plan for each electric vehicle, and an operation plan for each electric vehicle. and a storage device that stores a charging plan for the electric vehicle, wherein the charging control device instructs the charging device to charge with charging power that achieves a target SOC at the end of charging during planned charging, and The gist of the invention is to issue an instruction to the charging device to charge with charging power corresponding to the SOC at the start of charging during external charging.

According to this, during planned charging, charging is performed with charging power that achieves the target SOC at the end of charging, and during unplanned charging, charging is performed with charging power corresponding to the SOC at the start of charging, and appropriate charging is performed even when unplanned. It can be carried out.

Further, in the electric vehicle charging system, the charging control device preferably instructs the charging device to end charging when the target SOC of the next planned charging is reached during unplanned charging.

Further, in the electric vehicle charging system, the charging control device controls the charging device so that the total charging power does not exceed a set value when a plurality of electric vehicles are to be charged simultaneously during the unplanned charging. Give instructions.

ADVANTAGE OF THE INVENTION According to this invention, suitable charging can be performed even if it is unplanned.

1 is a configuration diagram of a charging system for an electric vehicle according to an embodiment; FIG. 4 is a time chart showing changes in SOC; A time chart showing changes in electric power. FIG. 1(a) is a configuration diagram of a charging system, and FIG. 1(b) is a diagram showing operating hours and charging hours of each electric vehicle.

An embodiment embodying the present invention will be described below with reference to the drawings.
As shown in FIG. 1 , an electric vehicle charging system 10 includes a plurality of charging devices 20 , 30 , 40 , a charging control device 50 , and a storage device 60 . As the storage device 60, a server, which is a host control device, can be cited. As the electric vehicles 70, 80, and 90, for example, battery forklifts are used and used for transporting loads in factories. A plurality of charging devices 20, 30, 40 are arranged at charging stations in the factory.

An electric vehicle 70 is equipped with a battery (secondary battery) 71 . An electric vehicle 80 is equipped with a battery (secondary battery) 81 . An electric vehicle 90 is equipped with a battery (secondary battery) 91 . Lithium batteries, for example, are used as the batteries (secondary batteries) 71 , 81 , and 91 .

An electric vehicle charging system 10 is for charging batteries 71 , 81 , 91 of electric vehicles 70 , 80 , 90 . Each charging device 20, 30, 40 receives supply of system power from the system power supply through the power line L1. Charging device 20 can be connected to electric vehicle 70 using charging connector 21 . Then, charging device 20 charges battery 71 of electric vehicle 70 . Charging device 30 can be connected to electric vehicle 80 using charging connector 31 . Then, charging device 30 charges battery 81 of electric vehicle 80 . Charging device 40 can be connected to electric vehicle 90 using charging connector 41 . Then, charging device 40 charges battery 91 of electric vehicle 90 .

The electric vehicles 70, 80, 90 are of the same model, and the batteries 71, 81, 91 are also the same batteries.
Thus, the plurality of charging devices 20, 30, 40 can charge the batteries 71, 81, 91 of the electric vehicles 70, 80, 90, respectively.

Charging control device 50 is connected to charging devices 20, 30 and 40 via communication line L10 so as to be able to communicate with each other. Charging control device 50 sends a charging power instruction value to each charging device 20, 30, 40 to control charging device 20, 30, 40 using communication line L10. Each charging device 20, 30, 40 sends charging power information to charging control device 50 using communication line L10. The charging control device 50 detects the set contract demand.

A storage device (server or the like) 60 stores an operation plan (schedule) for each electric vehicle 70 , 80 , 90 and a charging plan (schedule) for each electric vehicle 70 , 80 , 90 . Storage device 60 and charging control device 50 are communicably connected, and an operation plan and a charging plan for the electric vehicle are sent from storage device 60 to charging control device 50 .

Each electric vehicle 70, 80, 90 detects the SOC of the battery, displays the detected SOC on a gauge, and sounds an alarm when the SOC of the battery drops to, for example, 20% to notify the passenger. there is When an occupant detects that the SOC has dropped from a gauge or an alarm sounds, the passenger travels to a charging station and charges the battery using charging devices 20, 30, and 40. FIG. Also, the detected SOC is sent to the charging devices 20, 30, 40 as information for charging.

Next, the action will be described.
As described with reference to FIG. 4(b), each of the plurality of electric vehicles 70, 80, 90 is operated and charged systematically. In this case, the required electric energy, operating time, and charging time differ according to the operation plan of the vehicle. In addition, it is designed to be able to cope with sudden charging during operating hours. In other words, since planned charging and unplanned charging are performed, it is possible to deal with them.

As shown in FIG. 2, the charging control device 50 controls the charging devices 20 and 30 so as to charge the charging devices 20 and 30 with charging power that achieves the target SOC at the timing t2 of the end of charging from the timing t1 of charging start in the planned charging. , 40. In FIG. 2, when the SOC rise speed (slope) is small, the charge power is small, and when the SOC rise speed (slope) is large, the charge power is large.

In addition, charging control device 50 instructs charging devices 20, 30, and 40 to charge with charging power corresponding to the SOC at the start of charging at timing t3 when charging is started during unplanned charging. As a result, during unplanned charging, by charging with charging power corresponding to the SOC at the start of charging, it is possible to perform appropriate charging even unplanned without overcharging even unplanned.

In addition, charging control device 50 terminates charging when the target SOC of the next planned charging is reached during unplanned charging (the target SOC at the end of charging is the target SOC of the next planned charging). Instructions are given to the devices 20, 30, 40;

In addition, as shown in FIG. 3, the charging control device 50, when charging a plurality of electric vehicles simultaneously during planned charging and unplanned charging, does not allow the sum of the charging power to exceed the contract power of the set value. command the charging devices 20, 30, 40 to cut the peak.

A series of these charging operations will be specifically described with reference to FIGS. 2 and 3. FIG.
In FIG. 2, the horizontal axis represents time. The vertical axis in FIG. 2 represents SOC, which is the state of the battery.

Electric vehicle 70 and electric vehicle 80 are scheduled to be charged from 12:00 to 13:00. The SOC of the battery of electric vehicle 70 is 50% at 12:00 at the start of planned charging, and the SOC of the battery of electric vehicle 80 is 60% at 12:00 at the start of planned charging.

The target SOC of electric vehicle 70 is 90%, and the target SOC of electric vehicle 80 is 95%. The target SOC is determined by the operating time after planned charging, etc. If the operating time is short, the target SOC is set low, and if the operating time is long, the target SOC is set high.

Therefore, the SOC of the battery of the electric vehicle 70 becomes 90% at 13:00 when the planned charging ends, and the SOC of the battery of the electric vehicle 80 becomes 95% at 13:00 when the planned charging ends.
Further, the charging speed (slope of SOC) of the battery of electric vehicle 70 is higher than the charging speed (slope of SOC) of the battery of electric vehicle 80 . That is, in FIG. 3 , when the horizontal axis represents time and the vertical axis represents power, the charging power of the battery of electric vehicle 70 is greater than the charging power of the battery of electric vehicle 80 . At this time, as shown in FIG. 3, charging of the battery of the electric vehicle 70 and charging of the battery of the electric vehicle 80 are performed simultaneously. The total sum is set so as not to exceed the surplus power determined according to the contract power as a set value.

As shown in FIG. 2, in electric vehicle 70, the next scheduled charging is from 17:00 to 18:00, and the target SOC of the next scheduled charging is 80% at 18:00. The target SOC is determined by the operating time after planned charging, etc. Since the next operating time is short, the target SOC for the next planned charging is 80%.

Here, let us consider a case where, for example, the electric vehicle 70 is operated at a higher load than planned after 13:00, so that the battery is consumed quickly and unplanned charging is required. In this case, the electric vehicle 70 starts unplanned charging at 15:00. The SOC of the battery of the electric vehicle 70 is 20% at 15:00 at the start of unplanned charging. In another situation, electric vehicle 70' has a battery SOC of 30% at 15:00 when unplanned charging begins. Then, charging of the electric vehicle 70 having a low SOC is performed more rapidly than charging of the electric vehicle 70' having a high SOC (so that the slope of the SOC increases). Then, when the target SOC of the next planned charging reaches 80%, the charging ends.

As described above, the target SOC for the next planned charge for electric vehicle 70 is 80%, and in another situation the target SOC for the next planned charge for electric vehicle 70' is 80%. Therefore, the battery is charged to the SOC required for the next operation.

Also, in unplanned charging, as described using FIG. surplus power is not exceeded. For example, if the SOC of electric vehicle 70 is 20% and the SOC of electric vehicle 80 is 10% at the start of unplanned charging, the SOC ratio is 2:1. The charging power may be determined by dividing the surplus power (the power available up to the contract power) at a ratio of 1:2. In other words, if the contract power is 100 kw and the power currently in use (planned charging power and power used for other equipment) is 70 kw, the surplus power is 30 kw. 80 charging power=1:2", and as a result, the charging power of the electric vehicle 70 may be 10 kw and the charging power of the electric vehicle 80 may be 20 kw so as not to exceed the surplus power.

According to the above embodiment, the following effects can be obtained.
(1) The configuration of the electric vehicle charging system 10 includes a plurality of charging devices 20, 30, and 40 for charging the batteries 71, 81, and 91 of the electric vehicles 70, 80, and 90, respectively, and the charging devices 20, 30, and 40 and a storage device 60 that stores an operation plan for each electric vehicle 70, 80, 90 and a charging plan for each electric vehicle 70, 80, 90. During planned charging, charging control device 50 instructs charging devices 20, 30, and 40 to charge with charging power that achieves the target SOC at the end of charging. An instruction is issued to the charging devices 20, 30, 40 to charge with the charged power. As a result, during unplanned charging, by charging with charging power corresponding to the SOC at the start of charging, it is possible to perform appropriate charging even unplanned without excessive charging.

(2) During unplanned charging, charging control device 50 instructs charging devices 20, 30, and 40 to end charging when the target SOC of the next planned charging is reached. That is, the SOC at the end of unplanned charging is the target SOC for the next planned charging. Therefore, the battery can be charged to the SOC required for the next operation. For example, if the vehicle is not used as it is after being charged, the vehicle does not need to be charged in the next operation.

(3) When charging a plurality of electric vehicles at the same time during unplanned charging, the charging control device 50 controls the charging device 20 so that the sum of the charging power does not exceed a set value (peak cut). Give instructions to 30, 40. Therefore, it is possible to prevent the sum of the charging power of the plurality of units from exceeding a predetermined set value (for example, surplus power determined according to the contract power).

Embodiments are not limited to the above, and may be embodied as follows, for example.
○ Although lithium batteries are illustrated as the batteries 71, 81, and 91, the type of battery does not matter.
O Although the server was illustrated as the memory|storage device 60, you may use memory|storage devices other than a server.

○ There are three electric vehicles in Fig. 1, but the number does not matter.
○ There are three charging devices in Fig. 1, but the number does not matter.
○ The electric vehicle may be an industrial vehicle such as a battery forklift, or may be a so-called electric type passenger car, and the type of the vehicle does not matter. They do not have to be the same model, and the batteries to be mounted do not have to be the same.

DESCRIPTION OF SYMBOLS 10... Charging system of an electric vehicle, 20, 30, 40... Charging device, 50... Charging control apparatus, 60... Storage device, 70, 80, 80... Electric vehicle, 71, 81, 91... Battery.

Claims (3)

a plurality of charging devices that respectively charge the batteries of the electric vehicle;
a charging control device that controls the charging device;
a storage device that stores an operation plan for each electric vehicle and a charging plan for each electric vehicle;
with
The charging control device
during planned charging, issuing an instruction to the charging device to charge with charging power that achieves a target SOC at the end of charging;
A charging system for an electric vehicle, wherein an instruction is issued to the charging device to charge with charging power corresponding to an SOC at the start of charging at the time of unplanned charging. The charging control device
2. The charging system for an electric vehicle according to claim 1, wherein during unplanned charging, the charging device is instructed to end charging when a target SOC for the next planned charging is reached. The charging control device
3. The charging device according to claim 1, wherein when a plurality of electric vehicles are to be charged simultaneously during the unplanned charging, an instruction is issued to the charging device so that the sum of charging power does not exceed a set value. electric vehicle charging system.

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