JP2020078195A - Vehicular charging control system - Google Patents

Abstract

To provide a vehicular charging control system which reduces occasions when the amount of power stored in a solar battery is decreased to a prescribed value leading to the deterioration and failure of the battery, thereby being able to suppress the occurrence of the deterioration and failure of the solar battery.SOLUTION: A vehicular charging control system includes a control section which performs control by switching, on the basis of the amount of power stored in a solar battery, between a first mode for charging the solar battery with power generated by a solar panel and a second mode for using the power of the solar battery to increase the amount of power stored in a driving battery. In the second mode, the control section allows a decrease in the amount of power stored in the solar battery with an increase in the amount of power stored in the driving battery to a first lower limit value when the solar panel is in a state where the generation of prescribed power can be expected, and allows the decrease in the amount of power stored in the solar battery with the increase in the amount of power stored in the driving battery to a second lower limit value higher than the first lower limit value when the solar panel is not in the state where the generation of the prescribed power can be expected.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a charging control system using a solar panel mounted on a vehicle.

  Patent Document 1 discloses a system for charging a solar battery, which is a battery for temporary storage, with electric power generated by a solar panel. In this system, when the output voltage of the solar panel is higher than the reference voltage, the charging circuit is activated, and when it is lower than the reference voltage, the charging circuit is stopped, but once it is stopped, it is not activated until a predetermined time has elapsed. As a result, it is possible to prevent the charging circuit from being repeatedly started and stopped, and to prevent the electric power of the solar battery from being wasted.

JP, 2014-217218, A

  When the power of the solar battery is used to increase the amount of electricity stored in another battery such as a drive battery, the power of the solar battery is charged to the drive battery up to a predetermined lower limit value. The solar battery whose storage amount has decreased to the lower limit value is newly charged to a predetermined upper limit value by the electric power generated by the solar panel.

  However, if the amount of electricity stored in the drive battery is increased to the lower limit value in a situation where power generation by the solar panel cannot be expected, such as at dusk, the solar panel will be charged even if an attempt is made to charge the solar battery thereafter. The amount of discharged power due to self-discharge or the like becomes larger than the amount of generated power, and the amount of electricity stored in the solar battery may decrease from the lower limit value. A large decrease in the amount of electricity stored in the solar battery may lead to deterioration or failure of the battery.

  The present invention has been made in view of the above problems, and reduces the chances of the amount of electricity stored in a solar battery decreasing to a predetermined value that leads to battery deterioration or failure, and suppresses the occurrence of solar battery deterioration or failure. An object of the present invention is to provide a charging control system for a vehicle, which is capable of.

  In order to solve the above problems, one embodiment of the present invention is a vehicle charge control system using a solar panel, in which a solar battery that is a temporary storage battery, a driving battery, and a solar panel generate power. A control unit that switches between a first mode for charging the solar battery with electric power and a second mode for increasing the amount of electricity stored in the drive battery using the electric power of the solar battery, based on the amount of electricity stored in the solar battery. In the second mode, when the solar panel is expected to generate a predetermined amount of electric power, the control unit reduces the storage amount of the solar battery with the increase of the storage amount of the driving battery. If the lower limit value of 1 is allowed and the solar panel is not in a state where it can be expected to generate a predetermined amount of power, a decrease in the stored amount of the solar battery due to an increase in the stored amount of the driving battery is higher than the first lower limit value. The lower limit of 2 is allowed.

  According to the above-described vehicle charging control system of the present invention, it is possible to reduce the chance that the stored amount of the solar battery drops to a predetermined value that leads to deterioration or failure of the battery, and suppress the occurrence of deterioration or failure of the solar battery. it can.

The figure which shows the structural example of the charge control system for vehicles which concerns on one Embodiment of this invention. Diagram explaining the solar battery charging mode Diagram illustrating the battery charging mode for driving Flowchart explaining the processing procedure of charging control executed by the solar ECU The figure which shows an example which limits the lower limit of the electric power of the solar battery used for charge of a drive battery. The figure which shows another example which limits the lower limit of the electric power of the solar battery used for charge of a drive battery.

[Embodiment]
The vehicle charging control system using the solar panel of the present invention cannot expect sufficient power generation by the solar panel in the charging mode in which the power of the driving battery is increased by using the electric power of the solar battery that is the temporary power storage battery. In this case, the lower limit value of the amount of electricity stored in the solar battery is increased to increase the amount of electricity stored in the drive battery, compared with the case where sufficient power generation by the solar panel can be expected. By increasing the lower limit value of the amount of electricity stored in the solar battery, the period until the amount of electricity stored reaches 0% is extended, so that the expected value to be charged within the period is increased, and deterioration or failure of the solar battery can be suppressed.

<Structure>
FIG. 1 is a block diagram showing the configuration of a vehicle charging control system 1 according to an embodiment of the present invention. The charging control system 1 illustrated in FIG. 1 includes a solar panel 10, a solar battery 20, a solar ECU 30, a relay circuit 40, a driving battery 50, and a battery monitoring unit 60. Note that, in FIG. 1, solid lines indicate wirings through which electric power is transmitted, and dotted lines indicate wirings through which control signals other than electric power, data signals, and the like are transmitted.

  The solar panel 10 is a solar cell module that is an assembly of solar cells that receives sunlight and generates electricity. The amount of electric power generated by the solar panel 10 depends on the intensity of solar radiation. The electric power generated by the solar panel 10 is output to the solar ECU 30. The solar panel 10 can be installed, for example, on the roof of a vehicle.

  The solar battery 20 is a charge / discharge capable power storage element such as a lithium battery or a nickel hydrogen battery. The solar battery 20 is a battery for temporarily storing the electric power generated by the solar panel 10, can be charged by the generated power, and can discharge the electric power stored by itself to the drive battery 50. It is connected to the solar ECU 30.

  The driving battery 50 is a charge / discharge-enabled power storage element such as a lithium battery or a nickel hydrogen battery. The drive battery 50 is connected to the solar ECU 30 via the relay circuit 40 so that the drive battery 50 can be charged by the electric power generated by the solar panel 10 and can be charged by the electric power stored in the solar battery 20. The drive battery 50 is connected to a predetermined device for driving a vehicle (not shown) and supplies electric power required for the operation of the device.

  A solar ECU (Electronic Control Unit) 30 is connected to a driving battery 50 via a solar panel 10, a solar battery 20, and a relay circuit 40, and connects to each battery using the electric power generated by the solar panel 10. It is a control device that can control the charging of the battery. The solar ECU 30 has a predetermined power conversion function, and can convert (step up / step down) the power generated by the solar panel 10 into a predetermined voltage and store it in the solar battery 20. Further, the solar ECU 30 converts (steps up / down) the electric power stored in the solar battery 20 into a predetermined voltage and outputs the voltage to the driving battery 50 (that is, electric power from the solar battery 20 to the driving battery 50). Transfer of quantity) is possible. Furthermore, the solar ECU 30 can control connection / disconnection of the relay circuit 40.

  This solar ECU 30 monitors the storage state of the solar battery 20, and based on the storage amount SOC of the solar battery 20, whether the battery charging control performed by the charging control system 1 is performed in the solar battery charging mode or not. Select whether to perform in charging mode. Further, the solar ECU 30 monitors the power generation state of the solar panel 10, and the power generation by the solar panel 10 is performed based on the power generation state of the solar panel 10 and information (time, weather, etc.) regarding the environment in which the vehicle is placed. Can be expected or not in the future. When power generation by the solar panel 10 cannot be expected in the future, the solar ECU 30 changes the range in which the storage amount of the solar battery 20 can be controlled in the drive battery charging mode. A method of changing the controllable range of the amount of stored electricity will be described later.

  The solar battery charging mode is a mode for charging the solar battery 20 with the electric power generated by the solar panel 10 as shown in FIG. 2 (corresponding to the “first mode” in the claims). In the solar battery charging mode, the solar ECU 30 cuts off the connection between the solar ECU 30 and the driving battery 50 by the relay circuit 40. This solar battery charging mode is performed in order to efficiently store the electric power obtained by solar radiation on the solar panel 10 in the solar battery 20, and the stored amount SOC of the solar battery 20 is equal to or less than a predetermined threshold SOC_L or a predetermined threshold SOC_C. When the amount of stored power SOC of the solar battery 20 exceeds a predetermined threshold value SOC_H, the operation is performed. The power value α, the threshold SOC_L, the threshold SOC_C, and the threshold SOC_H will be described later.

  The drive battery charging mode is a mode in which the drive battery 50 is charged using the electric power stored in the solar battery 20 to increase the amount of electricity stored in the drive battery 50, as shown in FIG. Corresponding to the "second mode" in. When power is generated by solar radiation, the power generated by the solar panel 10 is also used to charge the driving battery 50, and the amount of electricity stored in the driving battery 50 can be increased. In the drive battery charging mode, the solar ECU 30 connects the solar ECU 30 and the drive battery 50 by the relay circuit 40. This drive battery charging mode is performed to transfer the amount of electric power sufficiently stored in the solar battery 20 to the drive battery 50, and when the stored amount SOC of the solar battery 20 exceeds the threshold value SOC_H, the solar battery 20. It is carried out until the storage amount SOC of is less than or equal to the threshold value SOC_L or becomes equal to or more than the threshold value SOC_C.

  The battery monitoring unit 60 is configured to monitor the state (voltage, current, etc.) of the driving battery 50, and can notify the solar ECU 30 of the result of monitoring the driving battery 50.

<Charge control>
Next, with further reference to FIG. 4, the charging control executed by the vehicle charging control system 1 according to the embodiment of the present invention will be described. FIG. 4 is a flowchart for explaining the processing procedure of charging control executed by the solar ECU 30 of the charging control system 1.

  The charging control shown in FIG. 4 is started when the charging control system 1 is activated by turning on the power of the vehicle, for example, and is repeatedly executed until the charging control system 1 is stopped by turning off the power of the vehicle.

  Step S401: The solar ECU 30 determines whether the current charging is in the solar battery charging mode or the driving battery charging mode. In addition, the charge mode immediately after the charge control system 1 is activated may be set in advance to either the solar battery charge mode or the drive battery charge mode as a default, or the amount of electricity stored in the solar battery 20 immediately after the operation may be performed. It may be determined each time based on the SOC. If the charging mode is the solar battery charging mode, charging of the solar battery 20 is started and the process proceeds to step S402. On the other hand, if the charging mode is the driving battery charging mode, charging of the driving battery 50 is started and the process proceeds to step S404.

  Step S402: In the solar battery charging mode, the solar ECU 30 determines whether or not the stored amount SOC of the solar battery 20 is equal to or greater than a predetermined threshold value SOC_H. This threshold value SOC_H is a threshold value for determining that the solar battery 20 has accumulated sufficient electric power and the solar battery 20 is ready to supply electric power to another battery. For example, the high SOC of the solar battery 20 that does not reach overcharge can be set as the threshold SOC_H. When the stored amount SOC of the solar battery 20 is SOC_H or more (S402, Yes), the process proceeds to step S403. On the other hand, while the stored amount SOC of the solar battery 20 is less than the threshold value SOC_H (S402, No), the determination process of step S402 is continued.

  Step S403: The solar ECU 30 switches the charging mode from the solar battery charging mode to the driving battery charging mode. As a result, charging of the driving battery 50 is started. When the charging mode is switched, the process proceeds to steps S401 and S405.

  Step S404: In the drive battery charging mode, the solar ECU 30 determines whether or not the controllable range of the amount of electricity stored in the solar battery 20 needs to be suppressed. This judgment is made based on whether or not sufficient power generation by the solar panel 10 can be expected even after the judgment, and if sufficient power generation can be expected, the controllable range is not suppressed and sufficient power generation is expected. If not possible, the controllable range is suppressed.

  For example, if the power generated by the solar panel 10 is less than the predetermined power value α, it can be determined that sufficient power generation by the solar panel 10 cannot be expected in the future. The power value α is set to a power value that is expected to be less likely to increase when the generated power falls below this value. As an example, the power value generated by the solar panel 10 before sunset. Can be used. Note that it may be determined that sufficient power generation by the solar panel 10 cannot be expected in the future after waiting for a state in which the generated power of the solar panel 10 is less than the power value α to continue for a predetermined time T. By determining the continuation of the time T in this way, for example, it is possible to avoid a phenomenon in which the solar panel 10 can generate sufficient power, but the sun hides in the clouds and the generated power temporarily becomes less than the power value α. be able to.

  Further, for example, if the current time is within the predetermined time zone Tp, it can be determined that sufficient power generation by the solar panel 10 cannot be expected in the future. The time zone Tp is set to a time zone that is unlikely to be generated by the solar panel 10 at this time, and as an example, a time zone from sunset time to sunrise time (for example, 19:00). ~ 5 o'clock next day) can be used. It should be noted that the power generation state of the solar panel 10 is recorded every time the vehicle travels, and based on the average value of the power generation performance up to now and the power generation performance of the previous travel, the time when the power generation is started to the time when the power generation is finished. May be set as the time zone Tp.

  When it is not necessary to suppress the controllable range of the stored amount of the solar battery 20 (S404, No), the process proceeds to step S405. On the other hand, when it is necessary to suppress the controllable range of the stored amount of the solar battery 20 (S404, Yes), the process proceeds to step S406.

  Step S405: The solar ECU 30 does not need to suppress the controllable range of the stored amount of the solar battery 20, so the controllable range is set to the normal range. The normal range is, for example, as shown on the left side of FIG. 5, a range in which the upper limit value of the stored amount is SOC_H and the lower limit value of the stored amount is SOC_L (corresponding to the “first lower limit value” in claim 1). is there. The upper limit SOC_H can be set to, for example, a high power storage amount of the solar battery 20 that does not reach overcharge. The lower limit value SOC_L can be set to, for example, a low storage amount of the solar battery 20 that does not reach overdischarge. In this normal range, the solar ECU 30 controls the charging / discharging of the solar battery 20 so that the amount of stored electricity falls within the range from the upper limit value SOC_H to the lower limit value SOC_L. Therefore, the charging action of increasing the charged amount of the driving battery 50 is allowed until the charged amount of the solar battery 20 decreases to the lower limit value SOC_L. When the controllable range of the storage amount of the solar battery 20 is set to the normal range, the process proceeds to step S407.

  Step S406: The solar ECU 30 sets the controllable range to the controllable range because it is necessary to suppress the controllable range of the amount of electricity stored in the solar battery 20. The suppression range is, for example, as shown on the right side of FIG. 5, a range in which the upper limit value of the stored amount is SOC_H and the lower limit value of the stored amount is SOC_C (corresponding to the "second lower limit value" in claim 1). is there. The upper limit value SOC_H in the suppression range is the same as the upper limit value SOC_H in the normal range, but the lower limit value SOC_C in the suppression range is set higher than the lower limit value SOC_L in the normal range. In this suppression range, the solar ECU 30 controls the charging / discharging of the solar battery 20 so that the stored amount of electricity falls within the range from the upper limit value SOC_H to the lower limit value SOC_C. Therefore, the charging action of increasing the charged amount of the driving battery 50 is allowed until the charged amount of the solar battery 20 decreases to the lower limit value SOC_C. With such a setting, the electric power of the solar battery 20 used to increase the amount of electricity stored in the driving battery 50 can be suppressed, and the amount of electricity stored in the solar battery 20 can be kept larger than the normal range. ..

As an example, the lower limit value SOC_C [%] of the suppression range can be determined using the following formula (1).
SOC_C = Drop_Time × Drop_SOC (1)
Here, Drop_Time [hour] is a period (for example, one month) in which it is assumed that if the solar battery 20 is charged once by the power generated by the solar panel 10 during the period, the battery will not deteriorate or fail. ). The period during which the solar battery 20 can be charged once can be determined based on the frequency of use of the vehicle by the user, the parking environment of the vehicle, and the like. Drop_SOC is the power consumption rate [% / hour] of the solar battery 20 per unit time. This power consumption rate is determined based on the specifications of the charging control system mounted on the vehicle and the like, and is substantially constant when the solar panel 10 does not generate power for a long period of time.

  When the controllable range of the storage amount of the solar battery 20 is set to the suppression range, the process proceeds to step S408.

  Step S407: The solar ECU 30 determines whether or not the amount of electricity stored in the solar battery 20 has become equal to or lower than the lower limit value SOC_L in the normal range. If the amount of electricity stored in the solar battery 20 is less than or equal to the lower limit value SOC_L (S407, Yes), the process proceeds to step S409. On the other hand, when the stored amount of the solar battery 20 exceeds the lower limit value SOC_L (S407, No), the charging action of increasing the stored amount of the driving battery 50 is continued, and the process proceeds to step S404.

  Step S408: The solar ECU 30 determines whether or not the amount of electricity stored in the solar battery 20 has become equal to or lower than the lower limit value SOC_C in the suppression range. When the amount of electricity stored in the solar battery 20 is equal to or lower than the lower limit value SOC_C (S408, Yes), the process proceeds to step S409. On the other hand, when the stored amount of the solar battery 20 exceeds the lower limit value SOC_L (S408, No), the charging action of increasing the stored amount of the driving battery 50 is continued, and the process proceeds to step S404.

  Step S409: The solar ECU 30 switches the charging mode from the driving battery charging mode to the solar battery charging mode. As a result, charging of the solar battery 20 is started. When the charging mode is switched, the process proceeds to steps S401 and S402.

  In the above description, the case where the upper limit value SOC_H in the suppression range is the same as the upper limit value SOC_H in the normal range has been described, but the upper limit value SOC_H in the suppression range is set to be higher than the upper limit value SOC_H in the normal range as shown in FIG. 6, for example. May be set higher. Such a setting is suitable, for example, in the case where a large change in the amount of change ΔSOC in the amount of stored electricity may affect other parts of the system.

[Action / effect]
As described above, according to the vehicle charging control system 1 according to the embodiment of the present invention, the drive battery charging mode in which the electric power of the solar battery 20 is used to increase the amount of electricity stored in the drive battery 50 (second Mode), if sufficient power generation by the solar panel 10 cannot be expected in the future, a solar battery that is allowed to increase the amount of electricity stored in the driving battery 50 than if sufficient power generation by the solar panel 10 can be expected in the future. Increase the lower limit value of the storage amount of 20.

  Increasing the lower limit of the amount of electricity stored in the solar battery 20 to extend the period until the amount of electricity stored in the solar panel 10, which decreases with constant power consumption, reaches 0% in a situation where there is no power generation by the solar panel 10. You can Therefore, the expected value for charging the solar battery 20 by the power generation of the solar panel 10 is increased by the extended period, and the chance that the stored amount of the solar battery 20 is reduced to a predetermined value leading to deterioration or failure of the battery is reduced. .. As a result, it is possible to suppress the deterioration and failure of the solar battery 20.

  INDUSTRIAL APPLICABILITY The present invention can be used for a charging control system that uses electric power generated by a solar panel, such as a vehicle.

1 Vehicle charge control system 10 Solar panel 20 Solar battery 30 Solar ECU
40 relay circuit 50 drive battery 60 battery monitoring unit

Claims (1)

A charging control system for a vehicle using a solar panel,
A solar battery that is a battery for temporary storage,
A drive battery,
A first mode for charging the solar battery with electric power generated by the solar panel and a second mode for increasing the amount of electricity stored in the drive battery by using the electric power of the solar battery A control unit for switching and controlling based on the amount of stored electricity,
In the second mode, when the solar panel is in a state where it can expect to generate a predetermined amount of electric power, the control unit reduces the amount of electricity stored in the solar battery with an increase in the amount of electricity stored in the drive battery. If the lower limit value of 1 is allowed and the solar panel is not in a state where power generation of the predetermined electric power can be expected, a decrease in the amount of electricity stored in the solar battery due to an increase in the amount of electricity stored in the driving battery is reduced to the first value. Allow up to the second lower limit, which is higher than the lower limit,
Vehicle charge control system.

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