JP2015133869A - Charge system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use electric power efficiently.SOLUTION: A charge control section determines distribution electric power to be distributed to each charge device in accordance with start of charge, and instructs a charge electric current Ia to flow to the charge device when charge is performed on the basis of the distribution electric power (Period T0). When a difference between the charge electric current Ia and an actual electric current Ib is larger than a predetermined difference Δ I during charging, the charge electric current Ia is corrected so that the difference between the charge electric current Ia and the actual electric current Ib can be maintained to be the predetermined difference Δ I. Thereby, excess electric power is generated from the distribution electric power, which allows the electric power to be distributed to other charge device, for example.

Description

  The present invention relates to a charging system for charging a storage battery of an electric vehicle.

  A charging system that charges a storage battery mounted on a vehicle such as an EV (Electric Vehicle) or a PHV (Plug in Hybrid Vehicle) is disclosed in Patent Document 1, for example. In the charging system of Patent Document 1, even when a plurality of vehicles are charged at the same time, the charging is controlled so as not to exceed the contracted capacity.

JP 2004-229355 A

  By the way, a charging system determines the electric current used for charge, and performs the instruction | indication for making it charge according to the electric current to a vehicle. However, the vehicle side does not always charge according to the instruction from the charging system. For example, when the temperature of the storage battery rises during charging, the vehicle may be controlled to charge with a current smaller than the instructed current. In such a case, in the charging system, a difference occurs between the instructed current and the current used for charging, and the corresponding power is not used. For this reason, it is hard to say that the charging system efficiently uses the power available for charging.

  This invention was made paying attention to the problem which exists in such a prior art, and the objective is to provide the charging system which can utilize electric power efficiently.

  A charging system that solves the above problems includes a plurality of charging devices that supply power to a storage battery of an electric vehicle, a control device that controls power distributed to each charging device, and an actual current supplied to the vehicle through the charging device. A measuring unit that measures a value, and the control device determines a distribution power to be distributed to each charging device at the start of charging, and charges a charging current value when charging is performed based on the distribution power If the difference between the charging current value and the actual current value becomes larger than a predetermined difference during charging of the charging device, the difference between the charging current value and the actual current value is The charging current value is corrected and instructed to maintain the difference.

  According to this configuration, by correcting the charging current value so as to maintain a predetermined difference from the actual current value, surplus power generated due to the correction of the charging current value among the distributed power distributed to the charging device, It can be used for other applications. For this reason, electric power can be used efficiently without causing waste in the electric power that can be supplied by the entire charging system.

  In the above charging system, when the power that can be supplied is small and surplus power is generated based on the charging current value with respect to the distributed power, the control device distributes the surplus power to another charging device. .

  According to this configuration, it is possible to increase the power that can be supplied by the other charging devices by distributing the surplus power to the other charging devices. As a result, electric power that can be supplied to an electric vehicle that is being charged by another charging device is increased, and charging efficiency can be improved.

  In the charging system described above, the control device indicates a difference between the charging current value and the actual current value when a value obtained by adding the current of the predetermined difference to the actual current value is indicated as the charging current value. When the difference becomes smaller than a predetermined difference, the charging current value is corrected and instructed so as to maintain the difference between the charging current value and the actual current value at the predetermined difference.

  According to this configuration, it is possible to detect that the electric vehicle has increased the current used for charging by maintaining the difference between the charging current value and the actual current value at a predetermined difference. As a result, even after the charging current value is corrected, the power supplied to the electric vehicle can be increased. That is, even when the charging current value is once lowered, it is possible to avoid the electric vehicle from being continuously charged in the lowered state. Therefore, the efficiency of charging can be improved.

  In the charging system described above, the control device indicates, as the charging current value, an added current value obtained by adding the charging current value and a predetermined current value every predetermined cycle, and the charging current value and the actual current value When the difference between the charging current value and the actual current value becomes smaller than a predetermined difference, the charging current value is corrected and instructed so as to maintain the difference between the charging current value and the actual current value at the predetermined difference.

  According to this configuration, it is possible to detect that the electric vehicle has increased the current used for charging by maintaining the difference between the charging current value and the actual current value at a predetermined difference. As a result, even after the charging current value is corrected, the power supplied to the electric vehicle can be increased. That is, even when the charging current value is once lowered, it is possible to avoid the electric vehicle from being continuously charged in the lowered state. Therefore, the efficiency of charging can be improved.

  According to the present invention, power can be used efficiently.

The block diagram which shows the structure of a charging system. The schematic diagram which shows the specific example of transition of a charging current value and an actual current value. (A), (b) is a schematic diagram which shows the specific example of the transition of the charging current value in embodiment. (A), (b) is a schematic diagram which shows the specific example of the transition of the charging current value in a comparative example. (A), (b) is a schematic diagram which shows the specific example of the transition of the charging current value in embodiment. The schematic diagram which shows the specific example of the transition of the charging current value and actual electric current value in another example.

Hereinafter, an embodiment embodying a charging system will be described with reference to FIGS.
As shown in FIG. 1, an electric vehicle 10 such as an EV or a PHV is equipped with a storage battery 11 that stores power supplied to an electric motor (motor) (not shown) serving as a prime mover. In the storage battery 11, the power supplied from the vehicle charging system 12 is converted into a form suitable for charging, and is charged by the converted power.

  The charging system 12 according to the present embodiment includes a control device 13 that controls charging of the electric vehicle 10 and a charging device (charging station) 15 that is connected to the electric vehicle 10 via a charging plug 14 during charging. . The charging system 12 includes a plurality of charging devices 15, and the charging system 12 of this embodiment includes three charging devices 15.

  The charging system 12 is connected to the power system 17 via the power transmission line 16. In the charging system 12, a power transmission path for transmitting power from the power system 17 to each charging device 15 through the power transmission line 16 is constructed. The electric power system 17 is a power transmission system for transmitting electric power, and is owned by an electric power company. The charging system 12 can use the power determined by the supply and demand contract between the owner of the charging system 12 and the power company.

  The control device 13 and each charging device 15 are connected by a signal line 18 that transmits a control signal. The charging plug 14 includes a power transmission line for transmitting charging power and a signal line for transmitting and receiving signals between the charging device 15 and the electric vehicle 10.

  The control device 13 includes a charge control unit 19 that controls the power supplied from each charging device 15. Each charging device 15 includes a measuring unit 20 that measures an actual current value supplied to the electric vehicle 10.

Next, the control contents when the charging system 12 performs charging will be described together with the operation thereof.
When the charging control unit 19 of the control device 13 confirms the connection of the vehicle to the charging device 15, it determines the distribution power to be distributed to the charging device 15 to be charged for charging. At this time, the charging control unit 19 determines the distribution power to each charging device 15 so that the total distribution power does not exceed the power set in the supply and demand contract. In this embodiment, the charging control unit 19 determines the distributed power so that the power is evenly distributed to the charging device 15 to be charged. In addition, the charging control unit 19 of this embodiment controls confirmation of connection between the charging device 15 and the electric vehicle 10 and supply of power using a CPLT (control pilot) function.

  The charging control unit 19 that has determined the distributed power calculates the distributed current value Ic based on the distributed power as the charging current value Ia when each charging device 15 performs charging. Then, the charging control unit 19 instructs the calculated charging current value Ia to the charging device 15 that is a charging target. Thereby, electric power is supplied to the electric vehicle 10 through the charging device 15 with the electric power based on the charging current value Ia as an upper limit, and the storage battery 11 of the electric vehicle 10 is charged.

  The charge control unit 19 that has started charging acquires the measurement result of the measurement unit 20 of the charging device 15 that is the target of charging for each predetermined period, and obtains the charge current value Ia and the actual current value Ib that is the measurement result. The difference is monitored based on equation (1).

Charging current value Ia−actual current value Ib ≦ predetermined difference ΔI (1)
In the above monitoring, when the difference between the charging current value Ia and the actual current value Ib is equal to or smaller than the predetermined difference ΔI, the charging control unit 19 maintains the current charging current value Ia as the instruction current value. . In this case, the formula (1) is established, and the electric vehicle 10 is supplied with electric power that matches or substantially matches the electric power based on the charging current value Ia (distributed current value Ic), and charging is performed.

  On the other hand, when the difference between the charging current value Ia and the actual current value Ib is larger than the predetermined difference ΔI, the charging control unit 19 instructs the charging device 15 that does not hold Expression (1) to the current charging current value. Ia is corrected. In the charging device 15 in which the expression (1) is not satisfied, the electric vehicle 10 is charged with less electric power than the electric power based on the charging current value Ia (distributed current value Ic). An event in which the electric power supplied to the electric vehicle 10 decreases can occur when the current for charging the storage battery 11 is lowered by the control of the electric vehicle 10. For example, when the temperature of the storage battery 11 rises, the electric vehicle 10 may reduce the current for charging. Thus, when the electric power supplied to the electric vehicle 10 decreases, the charging control unit 19 newly calculates the charging current value Ia based on Expression (2).

Charging current value Ia = actual current value Ib + predetermined difference ΔI (2)
Then, the charging control unit 19 instructs the charging device 15 using the charging current value Ia based on the formula (2) as an instruction current value. Further, the charging control unit 19 distributes the power to the other charging devices 15 when the power supplied from the charging device 15 instructing the charging current value Ia based on the formula (2) is decreased.

With reference to FIG. 2 and FIG. 3, the control contents when distributing power to the other charging devices 15 will be described with specific examples.
FIG. 2 illustrates the transition of the charging current value Ia and the actual current value Ib in one charging device 15 to be charged. A period T0 in FIG. 2 is a period in which the above expression (1) is established. In this period T0, electric power based on the first distributed power is supplied to the electric vehicle 10 and charging is performed. The charging current value Ia based on the distributed power initially distributed is the same value as the distributed current value Ic. When the difference between the charging current value Ia and the actual current value Ib becomes larger than ΔI after the period T0 elapses, and the expression (1) is not satisfied, the charging current value Ia is corrected based on the expression (2). . As a result, the charging current value Ia is controlled to a value smaller than the distributed current value Ic based on the distributed power initially distributed, as shown in FIGS. 2 and 3A.

  As a result, in the charging device 15 that corrects the charging current value Ia, the charging current value Ia decreases as the power supplied to the electric vehicle 10 decreases as shown in FIG. A surplus ΔS1 occurs between the charging current value Ia and the distribution current value Ic. The power corresponding to the surplus ΔS1 becomes surplus power that is not supplied to the electric vehicle 10 through the charging device 15. For this reason, the charging control unit 19 distributes the surplus power corresponding to the difference between the distributed power and the power that can be supplied based on the corrected charging current value Ia to the charging device 15 that performs charging. be able to.

  For example, when there is one other charging device 15 that performs charging, the charging control unit 19 distributes excess power to the other charging devices 15. That is, as shown in FIG. 3B, the charging current value Ia instructed to the other charging device 15 is increased by the surplus amount ΔS1. As a result, the charging current value Ia of the other charging device 15 is changed to a value obtained by adding the surplus ΔS1 to the distribution current value Ic. As a result, the power supplied to the other charging device 15 increases. In addition, when there are a plurality of other charging devices 15 that perform charging, the charging control unit 19 evenly distributes power according to the number of charging devices 15. Further, the power distribution destination in the charging control unit 19 is the charging device 15 that performs charging with the charging current value Ia based on the distribution current value Ic.

  The charging control unit 19 monitors the difference between the charging current value Ia and the actual current value Ib based on the above equation (1) for each predetermined period. That is, even when the charging current value Ia is corrected, the charging control unit 19 continues the monitoring until the charging is completed. Then, when the formula (1) is not satisfied, the charging control unit 19 corrects the charging current value Ia based on the formula (2). In addition, when surplus power is generated, the charging control unit 19 distributes the power to the other charging devices 15. The period T2 in FIG. 2 illustrates a state in which the charging current value Ia (actual current value Ib + predetermined difference ΔI) decreases as the actual current value Ib decreases.

  4A and 4B illustrate a case where the charge control unit 19 of the present embodiment is not controlled. In this case, as shown in FIG. 4A, even if the electric power supplied to the electric vehicle 10 decreases, the charging current value Ia maintains the distributed current value Ic. For example, it is assumed that the instruction current value necessary for supplying the reduced power is the current value Iy. At this time, a surplus ΔS2 is generated between the charging current value Ia and the current value Iy. However, when the power corresponding to the surplus ΔS2 is not distributed to the other charging devices 15, the power corresponding to the surplus ΔS2 is maintained in a state of being distributed to the charging device 15 as surplus power. As a result, as shown in FIG. 4B, the electric power supplied to the electric vehicle 10 that is being charged by the other charging device 15 maintains the charging current value Ia (distributed current value Ic) and does not increase.

  In addition, after reducing the current as described above, the electric vehicle 10 may increase the current for charging the storage battery 11 again when the factor that reduced the current has been resolved. That is, in this case, the electric power supplied to the electric vehicle 10 increases. Therefore, after the charging current value Ia is corrected, that is, when charging is not controlled with the charging current value Ia based on the distributed current value Ic, the charging control unit 19 changes the actual current value Ib based on the equation (3). Monitor.

Charging current value Ia−actual current value Ib <setting difference α (3)
The setting difference α is a predetermined difference, and is set to the same value as the predetermined difference ΔI or a value smaller than the predetermined difference ΔI.

  In the monitoring, the charging control unit 19 performs a process for correcting the current charging current value Ia when the difference between the charging current value Ia and the actual current value Ib is smaller than the setting difference α. When the formula (3) is established, the difference between the actual current value Ib and the charging current value Ia becomes smaller as the actual current value Ib increases. That is, it means that the electric vehicle 10 increases the current for charging the storage battery 11 and the electric power supplied to the electric vehicle 10 increases.

  Therefore, the charging control unit 19 corrects the current charging current value Ia based on the formula (2). Thereby, the charging current value Ia is corrected to a value obtained by adding the predetermined difference ΔI to the actual current value Ib. On the other hand, when the difference between the charging current value Ia and the actual current value Ib matches the set difference α or is larger than the predetermined difference ΔI, the charging control unit 19 maintains the current charging current value Ia as the instruction current value. In this case, the electric vehicle 10 is supplied with electric power that matches or substantially matches the electric power based on the charging current value Ia, and charging is performed.

The control content when correcting the charging current value Ia will be described with a specific example according to FIGS.
A period T2 in FIG. 2 is a period in which the above expression (3) is established. In this period T2, the power supplied to the electric vehicle 10 increases as the actual current value Ib increases. Then, as shown in FIG. 5A, the charging current value Ia is corrected when the difference between the charging current value Ia and the actual current value Ib becomes smaller than the set difference α.

  When the charging current value Ia is corrected, the charging control unit 19 decreases the charging current value Ia of the charging device 15 to which the surplus power has been distributed by a predetermined value before instructing the corrected charging current value Ia. To instruct. The predetermined value is an amount of electric power that is insufficient with respect to the charging current value Ia calculated by Expression (2). As a result, as shown in FIG. 5B, the charging current value Ia of the other charging device 15 to which the surplus power has been distributed decreases, and the power supplied to the electric vehicle 10 decreases. By this control, the charging control unit 19 secures necessary power from the other charging devices 15 so that the total distributed power does not exceed the power set in the supply and demand contract. Then, after securing the necessary power, the charging control unit 19 instructs the charging device 15 with the charging current value Ia calculated by Expression (2). As a result, in the charging device 15 that corrects the charging current value Ia, the electric power supplied to the electric vehicle 10 increases as shown in FIG.

  The charging control unit 19 constantly monitors whether the value calculated based on the equation (2), that is, the value obtained by adding the predetermined difference ΔI to the actual current value Ib exceeds the distribution current value Ic. Thereby, when the charging current value Ia is corrected, the charging control unit 19 performs control so that the total distributed power does not exceed the power determined in the supply and demand contract.

Therefore, according to the present embodiment, the following effects can be obtained.
(1) Excess power generated by correcting the charging current value Ia out of the distributed power distributed to the charging device 15 by correcting the charging current value Ia so as to maintain a predetermined difference ΔI with the actual current value Ib. Can be used for other applications. Specifically, the surplus power can be distributed to the other charging devices 15. Therefore, the power that can be supplied by the entire charging system 12 is not wasted and the power can be used efficiently. Moreover, in the charging device 15 to which the surplus power is distributed, the power that can be supplied to the electric vehicle 10 that is being charged can be increased, so that the charging efficiency can be improved.

  (2) By maintaining the difference between the charging current value Ia and the actual current value Ib at the predetermined difference ΔI, it is possible to detect that the electric vehicle 10 has increased the current used for charging. As a result, even after the charging current value Ia is corrected, the power supplied to the electric vehicle 10 can be increased. That is, even when the charging current value Ia is once lowered, it is possible to avoid the electric vehicle 10 from being continuously charged in the lowered state. Therefore, the efficiency of charging can be improved. That is, by correcting the charging current value Ia, it is possible to suppress the occurrence of such a situation that the charging time of the electric vehicle 10 is extended more than necessary. As a result, the convenience of the user of the charging system 12 can be achieved.

  (3) Further, when increasing the charging current value Ia, first, the charging current value Ia of the charging device 15 to which the power is distributed is decreased to ensure necessary power. For this reason, it is possible to prevent the power that can be supplied by the entire charging system 12 from exceeding the power in the supply-demand contract.

  (4) Moreover, the charging current value Ia has already been corrected by setting the target for distributing the surplus power as the charging device 15 that performs charging with the distributed current value Ic (charging current value Ia) based on the distributed power. Distribution to the charging device 15 can be avoided. As a result, generation of useless power can be suppressed.

In addition, you may change the said embodiment as follows.
In the specific example of FIG. 6, charging is performed in a state where the difference between the charging current value Ia and the actual current value Ib is a minute difference ΔIm. That is, the charging control unit 19 starts charging with the distribution current value Ic based on the distribution power as the charging current value Ia as in the period T0 in FIG. 6, and the actual current value Ib and the distribution current value Ic (charging current value Ia). Is larger than the predetermined difference ΔIm, the charging current value Ia is corrected such that the difference between the charging current value Ia and the actual current value Ib is maintained at the predetermined difference ΔIm. A period T1 in FIG. 6 is a period in which the charging current value Ia is corrected and charged by the above control so that the difference between the charging current value Ia and the actual current value Ib is maintained at a predetermined difference ΔIm. That is, in this period T1, the charging control unit 19 instructs the charging current value Ia to be a value obtained by adding a current having a predetermined difference ΔIm to the actual current value Ib. In this specific example, the charging control unit 19 can distribute the surplus power based on the difference between the distribution current value Ic and the charging current value Ia to the other charging devices 15 in the period T1 as in the embodiment.

  Furthermore, in this specific example, the charging control unit 19 instructs, as the charging current value Ia, an added current value obtained by adding a predetermined current value ΔIx to the charging current value Ia every predetermined period in the period T1. When the charging current value Ia is instructed in this way, a difference corresponding to the current value ΔIx may occur between the charging current value Ia and the actual current value Ib. Then, the charging control unit 19 monitors the difference between the charging current value Ia corresponding to the added current value and the actual current value Ib, and when the difference becomes smaller than a predetermined difference, the electric vehicle 10 is stored in the storage battery 11. It is detected that the current for charging is increased. Therefore, the charging control unit 19 corrects the charging current value Ia so as to maintain the difference between the charging current value Ia and the actual current value Ib at a predetermined difference ΔIm, as shown in a period T2 in FIG. At this time, when instructing the charging current value Ia, the charging control unit 19 reduces the power distributed to the other charging devices 15 and secures the necessary power as in the embodiment. Even when configured in this manner, it is possible to detect that the electric vehicle 10 has increased the current for charging the storage battery 11 as in the embodiment, and the same operational effects as in the embodiment can be produced.

O Excessive power generated with respect to the distributed power is not limited to distribution to other charging devices 15, and may be used for other purposes.
O The number of charging devices 15 constituting the charging system 12 may be changed. For example, the charging system 12 may be embodied in two or four or more charging devices 15.

  (Circle) the charge control part 19 of embodiment has instruct | indicated the electric current value (charge electric current value Ia) to the charging device 15. FIG. However, under conditions such as when the voltage is constant or when the voltage can be specified, instructing with the current value is substantially equivalent to instructing with the power value. For this reason, in embodiment, you may perform the instruction | indication from the charge control part 19 to the charging device 15 by an electric power value. The instruction from the charging device 15 to the electric vehicle 10 may be a current value or a power value.

(Circle) the charge control part 19 may produce a difference for every charging device 15 as distribution electric power, and may distribute it. Similarly, when surplus power is generated, the distribution amount may be different for each charging device 15.
O Transmission / reception of information with the electric vehicle 10, the control device 13, and the charging device 15 may be performed by wireless communication.

  The control device 13 may be provided in any one of the plurality of charging devices 15. In this case, the charging device 15 provided with the control device 13 and the other charging device 15 are connected by a signal line so as to transmit and receive signals. And the control apparatus 13 performs control similarly to embodiment.

  In the embodiment, the charging device 15 is embodied in a configuration in which the charging plug 14 is mechanically connected to the electric vehicle 10 to perform charging. However, the vehicle and the charging unit (ground side) are used without using the charging plug 14. A non-contact type charging device that performs charging by electrically connecting the equipment) may be embodied. In the non-contact type charging device, the electric vehicle is stopped by aligning the power receiving side coil attached to the vehicle and the power transmitting side coil of the ground side equipment embedded in the floor of the charging station or the like. At this time, the power reception side coil and the power transmission side coil are separated and brought into a non-contact state. In this state, the non-contact charging device is connected in a state where the vehicle and the charging unit can be energized. In the non-contact charging system, the storage battery of the electric vehicle is charged by receiving the power from the power transmission side coil with the power reception side coil. Such a contactless charging device includes a resonance method and an electromagnetic induction method.

In the non-contact charging system described in the above other example, signal transmission / reception between the vehicle-side controller and the power-supply-side controller may be superimposed on power transmission.
The charging system 12 may be embodied as a public facility (such as an educational institution or a public hall), a commercial facility (such as an accommodation facility, a shopping facility, or a charging station) or a home facility.

  A power storage unit may be provided in the charging system 12 so that electric power for charging is supplied from the charging system 12 to the electric vehicle by discharging the power system 17 and the power storage unit. In this case, any number of power storage units may be provided in the charging system 12. The power storage unit may be charged using the electric power of the electric power system 17 or may be performed by a power generation system using natural energy such as a solar power generation system or a wind power generation system.

  DESCRIPTION OF SYMBOLS 10 ... Electric vehicle, 11 ... Storage battery, 12 ... Charging system, 13 ... Control apparatus, 15 ... Charging apparatus, 20 ... Measurement part, Ia ... Charging current value, Ib ... Actual current value, Ic ... Distribution current value, (DELTA) I, (DELTA) Im ... predetermined difference, ΔIx ... current value.

Claims (4)

A plurality of charging devices for supplying power to a storage battery of an electric vehicle;
A control device for controlling the power distributed to each charging device;
A measurement unit for measuring an actual current value supplied to the vehicle through the charging device,
The control device determines the distribution power to be distributed to each charging device at the start of charging, and instructs the charging device to determine a charging current value for charging based on the distributed power, while charging the charging device. When the difference between the charging current value and the actual current value is greater than a predetermined difference, the charging current value is set to maintain the difference between the charging current value and the actual current value at the predetermined difference. A charging system characterized by correcting and instructing.   2. The control device according to claim 1, wherein when the power that can be supplied based on the charging current value is small with respect to the distributed power and surplus power is generated, the control device distributes the surplus power to another charging device. Charging system.   When the control device indicates a value obtained by adding the current of the predetermined difference to the actual current value as the charging current value, a difference between the charging current value and the actual current value is greater than a predetermined difference. 3. The charging system according to claim 1, wherein the charging current value is corrected and instructed so that a difference between the charging current value and the actual current value is maintained at the predetermined difference when the value becomes smaller.   The control device indicates an addition current value obtained by adding the charging current value and a predetermined current value every predetermined cycle as the charging current value, and a difference between the charging current value and the actual current value is determined in advance. The charging current value is corrected and instructed so as to maintain the difference between the charging current value and the actual current value at the predetermined difference when the difference becomes smaller than the difference. Charging system.