JP7387296B2 - vehicle charging system - Google Patents

Description

The present invention relates to a vehicle charging system, and more particularly to a vehicle charging system that can simultaneously charge a plurality of vehicles while supporting demand control.

As a vehicle charging system that charges multiple vehicles such as EVs and PHVs at the same time, for example, the charging system disclosed in Patent Document 1 is known. In Patent Document 1, priorities are set for vehicles connected to a plurality of chargers (charging stations), taking into account the amount of charge, vehicle type, and battery capacity of the vehicles, and charging is performed individually according to the priorities. Ta. In addition, a maximum amount of power for the entire charging power was set, and control was carried out so as not to exceed this maximum amount of power.

JP2013-85440A

In the vehicle charging system disclosed in Patent Document 1, charging priorities are set based on a plurality of conditions, so that each vehicle can be charged efficiently.
However, since one overall control unit controls each charging station, a high-performance control unit is required. Additionally, there is no expandability in the number of chargers, and when adding more charging stations, it is necessary to change the entire charging system.

Therefore, in view of these problems, the present invention allows the control section provided in the charger to individually control the charging current of the charger, without controlling the whole charger at once, so that it is easy to cope with the increase or decrease in the number of chargers. It is an object of the present invention to provide a vehicle charging system in which the overall charging current can also be controlled.

In order to solve the above problem, the invention of claim 1 provides a vehicle charging system having a plurality of chargers for charging a vehicle, and a charging control section for controlling the charging current of the chargers, the system comprising: The unit is installed in each of the charger and the control base unit that obtains received power information from a watt-hour meter that measures the received power from commercial power, compares it with a predetermined reference value, and outputs the difference information. , and a control slave unit that individually controls the charging current of the charger, and the control slave unit charges the battery so that the received power from commercial power does not exceed the reference value based on the difference information output by the control master unit. It has a handset storage unit that controls the current and stores a standby time for making the control standby for a certain period of time, and when the amount of charge of the vehicle being charged reaches a predetermined threshold, the received power is set to the reference value. The charging current is characterized in that when the difference information indicating that the charging current has not been reached is received from the control base unit, the charging current is increased after waiting time has elapsed.
According to this configuration, the control slave unit controls the received power so that it does not exceed the reference value, so if the reference value is set to, for example, the maximum demand value or a power value smaller than that, the central control unit that controls the entire unit can be controlled. Demand control can also be performed without having one. In addition, since the control base unit only needs to output difference information with respect to the reference value of received power, there is no need to change the settings of the control base unit when changing the number of installed chargers, and it is easy to increase or decrease the number of chargers. can be carried out.

In addition, for vehicles whose charging current has reached a threshold value, the current is not increased until a certain period of time (standby time) has elapsed. Therefore, for vehicles whose charging amount has not reached the threshold, charging power can be distributed and increased using the standby time, and even if the charging current of each charger is controlled independently, each individual Balanced charging can be performed for vehicles connected to the charger.

The invention according to claim 2 is the configuration according to claim 1 , in which the controlling master device and the controlling slave device are provided with a wireless communication unit, and the controlling slave device wirelessly communicates with the controlling master device to obtain the difference information. Features.
According to this configuration, since the control master device and the control slave device communicate wirelessly, there is no need to arrange a signal line between the two, and the system is easy to install.

According to the present invention, since the control slave unit controls the received power so that it does not exceed the reference value, demand control can be performed without having a central control unit that controls the entire unit. In addition, since the control base unit only needs to output difference information with respect to the reference value of received power, there is no need to change the settings of the control base unit when changing the number of installed chargers, and it is easy to increase or decrease the number of chargers. can be carried out.

1 is a schematic configuration diagram showing an example of a vehicle charging system according to the present invention. FIG. 3 is a block diagram of a control master device. FIG. 3 is a block diagram of a control slave device. It is a flowchart which shows the flow of charge control.

Hereinafter, embodiments embodying the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration diagram showing an example of a vehicle charging system according to the present invention, in which a control base unit 1 obtains received power information of commercial power P from a smart meter (wattmeter) 10, and a control base unit 1 communicates with the control base unit 1. The controller has a controller 3 that controls the charging current of the charger 2, and a charging cable L1 extending from the vehicle 4 is connected to the charger 2. A control handset 3 is installed for each charger 2.

In addition, 5 (5a, 5b) is a step-down transformer that converts the power received at high voltage into low voltage power, 6 is a load such as an air conditioner that is supplied with three-phase power, and 7 is supplied with single-phase 100/200V. Indicates the load of lighting, etc. 5a is a three-phase transformer, 5b is a single-phase transformer, and each charger 2 is supplied with single-phase 200V power output from the single-phase transformer 5b.

FIG. 2 shows a block diagram of the control master device 1. As shown in FIG. As shown in FIG. 2, the control base unit 1 includes a base unit measurement unit 11 that obtains received power information from the smart meter 10, a base unit storage unit 12 that stores reference values, etc., and a base unit CPU 13 that controls the control base unit 1. , a base unit communication unit 14 that wirelessly communicates with the control slave unit 3, and the like. It is connected to the smart meter 10 via a communication line L2.

FIG. 3 shows a block diagram of the control slave device 3. As shown in FIG. As shown in FIG. 3, the control handset 3 includes a handset communication unit 31 that wirelessly communicates with the control master unit 1, a handset storage unit 32 that stores a charge amount threshold, a duration time to be described later, a standby time, etc. It includes a slave CPU 33 that controls the device 3, a charger control section 34 that outputs a control signal to the charger 2, and the like. It is connected to the charger 2 via a transmission line L3.
Note that the control handset 3 and the charger 2 may be formed integrally. Further, the control master device 1 and the control slave device 3 are individually supplied with single-phase power as a power source.

Here, the reference values stored in the base unit storage unit 12 will be explained. The reference value is a value (power value) set to be, for example, 10% smaller than the maximum demand value, and is set based on the following background.
The maximum value (maximum demand value) of the demand values (the maximum value of the average power consumption every 30 minutes in a month) for the past year (current month and previous 11 months) is applied to the basic electricity rate. If a demand value larger than the demand value of the past 11 months is measured even once in a month, the basic electricity rate for the next year will be determined based on that value. In other words, in order to suppress or reduce electricity charges, it is effective to perform control (demand control) to suppress the maximum demand value. For this purpose, a reference value set as a numerical value that does not exceed the maximum demand value is used. This standard value is set by the consumer.

Charging control of the vehicle charging system configured as described above is performed as follows.
First, the control master device 1 obtains information on the received power from the smart meter 10, and notifies each control slave device 3 of deviation information (difference information) at regular intervals, such as every second.
Deviation information is information that indicates what value the current received power is with respect to the standard value (what value is the expected value of the amount of electricity for 30 minutes calculated from the received power), and whether it is above or below the standard value. The control changes greatly depending on the situation. The base unit CPU 13 outputs "0" information as deviation information from the base unit communication unit 14 when the current received power is approximately the reference value, and outputs "plus" information when it exceeds the reference value. do. Furthermore, if the reference value has not been reached, "minus" information is output to each control slave device 3.
Note that the received power is approximately at the reference value when the received power is within a 2% difference from the reference value, for example.

Each control subunit 3 that receives the deviation information from the control master unit 1 performs the following control.
FIG. 4 shows a flowchart showing the flow of current control performed by the slave unit CPU 33 of the control slave unit 3, and will be described with reference to this flow. This control is carried out every time deviation information is received. When deviation information is received (S1), the state of the charging amount is first determined (S2), and the charging amount after starting charging becomes a constant value (threshold value). Different controls are implemented depending on whether the target is reached or not.
If the amount of charge has not reached the preset threshold, the process proceeds to S3, and if it has, the process proceeds to S7.

If the charging current has not reached the threshold value (NO in S2) and the deviation information is negative, that is, the received power has not reached the reference value (NO in S3) and the charging current can be increased, the increased current can be calculated using the following formula ( Calculate using equation 1) and increase the charging current (S6). Note that a maximum value is set for the charging current, and when the maximum value is reached, the charging current does not increase any further.
Increased current = Maximum current value (A) x Charge amount (Wh) / Threshold (Wh) (Formula 1)

If the deviation information is zero, that is, if the received power is approximately the reference value (YES in S4), a signal that does not change the charging current is output to the charger 2 (S14), and the process ends.
If the deviation information is positive, that is, the received power exceeds the reference value (NO in S4), and the charging current must be controlled to be reduced, the reduced current is calculated using the following formula (Formula 2), and the charging current is reduced. (S5). Note that a minimum value is set for the charging current, and when the minimum value is reached, no further reduction is made.
Reduction current = maximum current value (A) × (threshold value (Wh) - charge amount (Wh)) / threshold value (Wh)
...(Formula 2)
The new current value thus set is notified to the charger 2 (S14), and the charger 2 changes the charging current according to the received notification.

On the other hand, if charging has progressed beyond the threshold at the time of receiving the deviation information (YES in S2), the following control is performed.
If the deviation information is negative, that is, the received power has not reached the reference value (NO in S7), the duration stored in the handset storage unit 32 is read, and the duration is set to a set standby time such as 60 seconds. If the current has not been reached (NO in S8), the duration is added by one unit (the time interval for receiving deviation information) and saved (S10), and a signal that does not change the current is output to the charger 2 (S14) and the process ends. do.
If the duration has reached the standby time (YES in S8), a signal for adding the minimum increased current to the current current (S9) is output to the charger 2 (S14), and the process ends.

With this control, vehicles whose charging current has reached the threshold will stop increasing their charging current until the set standby time has elapsed, so if there is a vehicle whose charging amount has not reached the threshold, the It becomes possible to proceed with charging by increasing the charging current using time, and it is possible to perform balanced current control without having a control unit that collectively manages the charger 2.

Further, if the deviation information is zero or positive, that is, if the received power is equal to or higher than the reference value (YES in S7), the following control is performed. If the deviation information is zero, that is, the received power is approximately the reference value (YES in S11), the stored duration is reset to zero (S13) and a signal that does not change the current is output to the charger 2 ( S14) and ends.
If the deviation information is positive, that is, if the received power exceeds the reference value (NO in S11), the charging current is set to zero, and the stored duration is reset to zero (S13). As a result, a signal that sets the charging current to 0 is output to the charger 2, and the process ends.

With this control, if the received power exceeds the reference value, demand control can be performed to stop charging the vehicle that has been charged beyond the threshold value regardless of the standby time. Further, since the standby time count is reset, a sufficient standby time (duration time) can be set, and during that time, it is possible to continue charging a vehicle whose charging amount has not reached the threshold value. Therefore, charging current can be distributed in a well-balanced manner.

In this way, since the control handset 3 controls the received power so that it does not exceed the reference value, demand control can also be performed without having a central control unit that controls the entire system. Since the control base unit 1 only needs to output the difference information with respect to the reference value of the received power, there is no need to change the settings of the control base unit 1 when changing the number of installed chargers 2, and the charger 2 It is easy to increase or decrease.
Further, even if the charging current of each charger 2 is controlled independently, well-balanced charging can be performed for vehicles connected to each charger 2.
Furthermore, since the control master device 1 and the control slave device 3 communicate wirelessly, there is no need to arrange a signal line between them, and the system is easy to install.

In the above embodiment, communication between the control master device 1 and the control slave device 3 is carried out wirelessly, but a wired connection may also be used.

1. Control master device (charging control section), 2. Charger, 3. Control slave device (charging control section), 4. Vehicle, 10. Electric energy meter, 11. Master device measurement section. 14...Base device communication section (wireless communication section), 12...Base device storage section, 31...Slave device communication section (wireless communication section), 32...Slave device storage section.

Claims (2)

A vehicle charging system comprising a plurality of chargers for charging a vehicle and a charging control unit controlling a charging current of the chargers,
The charging control unit obtains received power information from a power meter that measures received power from commercial power, compares it with a predetermined reference value, and outputs difference information;
a control cordless unit installed in each of the chargers to individually control the charging current of the charger;
The control slave device controls the charging current so that the received power from commercial power does not exceed the reference value based on the difference information output by the control master device , and
It has a handset storage unit that stores a standby time for making the control standby for a certain period of time,
When receiving the difference information indicating that the received power has not reached the reference value while the amount of charge of the vehicle being charged has reached a predetermined threshold value, wait for the standby time to elapse. A vehicle charging system characterized by increasing charging current . The control master device and the control slave device include a wireless communication section,
The vehicle charging system according to claim 1 , wherein the control slave unit obtains the difference information by wirelessly communicating with the control master unit.

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