JP2019050713A - Charge control system and charge control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a charge control system capable of reducing the number of processes of alternately charging and discharging a battery while suppressing a decrease in utilization efficiency of generated electric power of a solar panel. SOLUTION: A solar panel that generates electricity by sunlight, a first battery that can be charged and discharged, a second battery that can be charged and discharged, and a solar panel, a first battery, and a second battery are connected to generate electricity from the solar panel. The first mode in which the process of charging the first battery and the process of indirectly charging the power stored in the first battery to the second battery are repeated according to the amount of electricity stored in the first battery, and the power generated by the solar panel. A second mode for directly charging the second battery is provided with a control unit that switches at least based on the generated power of the solar panel. [Selection diagram] Fig. 1

Description

  The present invention relates to a charge control system using a solar panel and a charge control method executed by the system.

  For example, Patent Document 1 describes charging efficiency by charging the generated power of the solar panel to a solar battery, which is a temporary storage battery, and then charging the main battery using the power stored in the solar battery. An improved system is disclosed.

JP, 2014-007937, A

  In the system described in Patent Document 1, the charging to the solar battery and the discharging from the solar battery are simply switched according to the change in the storage amount (SOC) of the solar battery. Therefore, when the power generated by the solar panel is large, the utilization efficiency of the generated power in the system may be reduced.

  Further, the process of alternately charging and discharging the solar battery affects the durability and the life of the solar battery itself and the relay circuit connecting the solar panel and the main battery. For this reason, it is not preferable for the system to increase the number of processes for alternately charging and discharging the battery carelessly.

  The present invention has been made in view of the above problems, and a charge control system capable of reducing the number of processes for alternately charging and discharging a battery while suppressing a decrease in utilization efficiency of generated power of a solar panel Intended to be provided.

  In order to solve the above problems, one aspect of the present invention is a solar panel generating electric power by solar light, a first chargeable / dischargeable battery, a second chargeable / dischargeable battery, a solar panel, a first battery, and A process connected to the second battery and charging the power generated by the solar panel to the first battery and a process indirectly charging the power stored on the first battery to the second battery are repeated according to the storage amount of the first battery And a control unit configured to switch a first mode to be performed and a second mode to directly charge the second battery with the generated power of the solar panel based on at least the generated power of the solar panel.

  In the control of the above aspect, the first mode and the second mode are switched based on at least the generated power of the solar panel. This can prevent the battery charging from being performed while the utilization efficiency of the generated power is low. In addition, since the second mode is executed, the number of processes for alternately charging and discharging the first battery in the first mode can be reduced.

  In this one aspect, the control unit switches the mode at a different timing from that at the time when the generated power of the solar panel changes across the first threshold at which the mode in which the utilization efficiency of the generated power becomes relatively high switches. Can.

  In the above control, since the mode is not switched immediately even if the power generated by the solar panel changes over the first threshold, the instantaneous fluctuation of the power generated by the solar panel causes the first mode and the second mode to be frequently used. Switching (control chattering) can be avoided.

  In this one aspect, the control unit may switch to the first mode if the generated power of the solar panel becomes equal to or less than a second threshold smaller than the first threshold while the second mode is being executed.

  In the above control, the second mode can be continuously executed by setting the second threshold to the lower limit power value at which the decrease in the generated power utilization efficiency of the solar panel in the charge control system is allowed. . As a result, the number of processes for alternately charging and discharging the first battery in the first mode can be reduced.

  At this time, the control unit determines that the accumulated generated power amount exceeding the first threshold in the predetermined period is the first threshold while the generated power of the solar panel is between the first threshold and the second threshold and the second mode is being executed. The first mode may be switched to the first mode if the accumulated power generation amount does not exceed.

  In the above control, even if it is determined that the generated power utilization efficiency of the solar panel is significantly reduced based on the accumulated generated power even if the generated power of the solar panel does not reach the lower limit power value, the second mode The charging mode can be switched to the mode. As a result, the number of processes for alternately charging and discharging the first battery in the first mode can be reduced, and the charging process in the second mode can be prevented from being performed while the generated power utilization efficiency is low.

  In addition, in the above aspect, when the generated power of the solar panel exceeds the first threshold during execution of the first mode, the control unit switches to the second mode when a predetermined time has elapsed after switching the mode. May be

  According to the above control, the first mode can be continuously executed until the predetermined time elapses even when the power generated by the solar panel exceeds the first threshold. This makes it possible to avoid frequent switching between the first mode and the second mode due to instantaneous fluctuations in the power generated by the solar panel.

  In the above aspect, when the control unit switches to the second mode, at least a third of the generated power of the solar panel is generated if the generated power of the solar panel exceeds a third threshold larger than the first threshold. The threshold power may be directly charged to the second battery, and the remaining surplus power not directly charged may be charged to the first battery.

  According to the above control, for example, when the second battery sets a predetermined power value required at least for charging, the generated power of the solar panel is a predetermined power value (= third threshold) In the second mode, the first battery is charged with the surplus power exceeding the predetermined power value (third threshold). This eliminates waste of generated power, such as discarding surplus power.

  At this time, the control unit does not charge the first battery by the surplus power if the storage amount of the first battery rises to a predetermined upper limit value even if the generated power of the solar panel exceeds the third threshold You can do so. By this control, it is possible to prevent the first battery from being charged beyond the upper limit value and becoming overcharged.

  Further, in the above aspect, when switching to the second mode, the control unit directly charges all of the generated power of the solar panel to the second battery if the generated power of the solar panel does not exceed the third threshold. In addition, insufficient power less than the third threshold may be charged from the first battery to the second battery.

  According to the above control, for example, when the second battery sets a predetermined power value required at least for charging, the generated power of the solar panel is a predetermined power value (= third threshold) When the power of the battery is less than the predetermined power value (third threshold value), the second battery is continuously carried out by taking out the insufficient power from the first battery and charging the second battery. Thus, it is possible to prevent the second mode from being switched to the first mode immediately, and to avoid frequent switching between the first mode and the second mode.

  At this time, the control unit can switch to the first mode if the storage amount of the first battery decreases to a predetermined lower limit value even if the generated power of the solar panel does not exceed the third threshold. This control can prevent the first battery from being discharged below the lower limit value and becoming an overdischarged state.

  Moreover, each process which the control part of the charge control system mentioned above performs can be grasped as a charge control method which gives a series of process procedures. This method is provided in the form of a program for causing a computer to execute a series of processing procedures. This program may be introduced into a computer in a form recorded on a computer readable recording medium.

  As described above, according to the charge control system of the present invention, it is possible to reduce the number of processes for alternately charging and discharging the battery while suppressing a decrease in the utilization efficiency of the generated power of the solar panel.

A diagram showing a configuration example of a charge control system according to an embodiment of the present invention Diagram showing the relationship between solar panel power generation and system utilization efficiency Flow chart for explaining the processing procedure of the first charge control executed by the charge control unit Diagram showing mode switching timing in first charge control A diagram showing an example of fluctuation of generated power in charge processing in the second mode Flow chart for explaining the processing procedure of the second charge control executed by the charge control unit Diagram showing the mode switching timing in the second charge control A diagram showing an example of fluctuation of generated power in charge processing in the second mode

[Overview]
The charge control system and the charge control method using the solar panel according to the present invention switch the battery to the charge mode in which the utilization efficiency of the generated power in the system is relatively high based on the magnitude of the generated power of the solar panel. Charge the battery. This can prevent the battery charging from being performed while the utilization efficiency of the generated power is low.

System Configuration
FIG. 1 is a diagram showing a configuration example of a charge control system 1 according to an embodiment of the present invention. The present charge control system 1 illustrated in FIG. 1 includes a solar panel 11, a solar battery 12, a drive battery 13, a charge control unit 14, and a battery monitoring unit 15. In FIG. 1, a wire through which power flows is indicated by a solid line, and a wire through which control signals other than power are flowing is indicated by a broken line.

  The solar panel 11 is, for example, a solar cell module that receives power of sunlight and generates power. The amount of power generated by the solar panel 11 depends on the intensity of solar radiation. The power generated by the solar panel 11 is output to the charge control unit 14. The solar panel 11 can be installed, for example, on the roof of a vehicle.

  The solar battery 12 is an electric power storage element configured to be chargeable and dischargeable, such as a lead storage battery or a nickel hydrogen battery. The solar battery 12 is connected to the charge control unit 14 so as to be chargeable by the power generated by the solar panel 11 and to discharge the power stored therein to the driving battery 13. The solar battery 12 corresponds to the "first battery" in the claims.

  The driving battery 13 is an electric power storage element configured to be chargeable and dischargeable, such as a lead storage battery or a nickel hydrogen battery, for example. The drive battery 13 is connected to the charge control unit 14 so as to be chargeable by the power generated by the solar panel 11 and chargeable by the stored power of the solar battery 12. The driving battery 13 is connected to a predetermined device for driving a vehicle (not shown), and supplies power power necessary for the operation of the device. The driving battery 13 corresponds to the “second battery” in the claims.

  The battery monitoring unit 15 is configured to be able to monitor the storage amount (SOC) of the drive battery 13, and notifies the charge control unit 14 and the like of the monitoring result. The battery monitoring unit 15 is supplied with power from a predetermined battery only while the drive battery 13 is being charged under the control of the charge control unit 14 described later, and the storage amount (SOC) of the drive battery 13 is Can be monitored.

  The charge control unit 14 is connected to the solar panel 11, the solar battery 12, the driving battery 13, and the battery monitoring unit 15. The charge control unit 14 monitors the storage amount (SOC) of the solar battery 12, and based on the magnitude of the generated power X input from the solar panel 11 and the storage amount of the solar battery 12, the generated power X It is configured to be able to control the charge to each battery using. Specifically, based on at least the generated power X of the solar panel 11, the first mode and the second mode are switched so as to improve the utilization efficiency of the generated power X.

  The charge processing in the first mode includes processing A for charging the generated power X of the solar panel 11 to the solar battery 12, and the generated power X of the solar panel 11 and the power stored in the solar battery 12 as the driving battery 13. The process B for charging is repeatedly performed according to the storage amount of the solar battery 12. Specifically, the process A is performed until the storage amount of the solar battery 12 reaches a predetermined upper limit, and then the process B is repeatedly performed until the storage amount of the solar battery 12 reaches a predetermined lower limit. Be done. That is, the charging process in the first mode is a process of indirectly charging the generated power X of the solar panel 11 to the driving battery 13 via the solar battery 12.

  On the other hand, the charging process in the second mode is a process for charging all or part of the generated power X of the solar panel 11 directly to the driving battery 13.

  The utilization efficiency of the generated power X of the solar panel 11 in the charge control system 1 is, as shown in FIG. 2, at the point of a predetermined threshold value α (corresponding to the “first threshold value” in the claims) The high-low relationship is switched between the charging process in the second mode and the second mode. Therefore, if the generated power X of the solar panel 11 is less than or equal to the threshold value α, the generated power utilization efficiency is relatively higher when the charging process is performed in the first mode than in the second mode. If the threshold value α is exceeded, the generated power utilization efficiency is relatively higher when the charging process is performed in the second mode than in the first mode.

  Note that the threshold α represents the power consumption by the DCDC converter (not shown) used in the charge control system 1, the power loss (wiring loss) by the wiring connecting the charge control unit 14 and the solar battery 12, the solar battery 12 It can be determined based on the power loss based on the charge and discharge efficiency (charge and discharge loss), the power loss due to the power supply for operating the battery monitoring unit 15 (power source loss), and the like.

  The charge control unit 14 includes, for example, a solar ECU (Electronic Control Unit) 14 a and a relay circuit 14 b. The solar ECU 14a has a predetermined power conversion function, and can convert the generated power of the solar panel 11 into a predetermined voltage (step-up / step-down) to store the solar battery 12, and the solar battery 12 It is possible to convert the power stored therein into a predetermined voltage (step-up / step-down) and discharge it to the drive battery 13. In addition, while performing the process A in the first mode, the solar ECU 14a operates the relay circuit 14b to cut off the connection between the charge control unit 14 and the drive battery 13. The supply of power to the battery monitoring unit 15 is stopped while the relay circuit 14 b is operating.

[Control executed by system]
Next, charge control performed by the charge control system 1 according to an embodiment of the present invention will be described with further reference to FIGS. 3 to 8.

<First charge control>
FIG. 3 is a flowchart illustrating the procedure of the first charge control performed by the charge control unit 14 of the charge control system 1. FIG. 4 is a diagram showing switching timing between the first mode and the second mode in the first charging control. FIG. 5 is a diagram showing a variation example of the generated power X in the charging process of the second mode.

  The first charge control shown in FIG. 3 is started when the charge control system 1 is operated by, for example, power on, and is repeatedly executed until the charge control system 1 is stopped by, for example, power off.

  Step S301: It is determined whether the charging mode currently being executed is the first mode or the second mode. In the charge mode immediately after the charge control system 1 is operated, for example, either the first mode or the second mode may be set in advance as a default, or the generated power X of the solar panel 11 immediately after the operation may be set. It may be determined based on If the charge mode is the first mode, the process proceeds to step S302. If the charge mode is the second mode, the process proceeds to step S306.

  Step S302: It is determined whether or not the generated power X of the solar panel 11 exceeds a threshold α at which the utilization efficiency is relatively higher in the second mode than in the first mode. If the generated power X exceeds the threshold value α (S302, Yes), the process proceeds to step S303. On the other hand, when the generated power X does not exceed the threshold value α (S302, No), the process of step S302 is determined again.

  Step S303: It is determined whether or not a time T2 elapsed from the previous switching from the first mode to the second mode has reached a predetermined time T1. This determination is made to switch the mode at a timing (T2 ≧ T1) different from that at the time when the generated power X of the solar panel 11 changes over the threshold value α. The predetermined time T1 is determined based on the generated power X of the solar panel 11, for example. The process of charging the solar battery 12 with the generated power X executed in the first mode and the power stored in the solar battery 12 are driven. The time required for the process of charging the battery 13 can be set.

  If the elapsed time T2 has reached the predetermined time T1 (S303, Yes), the process proceeds to step S304 (process (1) in FIG. 4). On the other hand, if the elapsed time T2 has not reached the predetermined time T1 (S303, No), the process returns to step S302.

  Step S304: The charge mode is switched from the first mode to the second mode. Thereby, the charging process in the second mode is performed. In the first charge control, all the generated power X of the solar panel 11 is directly charged to the drive battery 13. When the charging mode is switched, the process proceeds to step S305.

  Step S305: The elapsed time T2 so far is reset, and counting of the elapsed time T2 is newly started. When the clocking is newly started, the process returns to step S301 for determining the charging mode.

  Step S306: Accumulation of accumulated power generation amounts S1 and S2 is started. The accumulated power generation amount S1 is, as shown in FIG. 5, an amount obtained by cumulatively integrating, for a predetermined period, a power component exceeding the threshold α among the power generation X of the solar panel 11. Further, as shown in FIG. 5, the accumulated power generation amount S2 is an amount obtained by cumulatively integrating, for a predetermined period, a power portion of the generated power X of the solar panel 11 that is equal to or less than the threshold α. When accumulation of accumulated power generation amount is started, the process proceeds to step S307.

  Step S307: It is determined whether or not the generated power X of the solar panel 11 is equal to or less than a threshold α at which the utilization efficiency is relatively higher in the first mode than in the second mode. When the generated power X becomes equal to or less than the threshold value α (S307, Yes), the process proceeds to step S308. On the other hand, when the generated power X is not less than or equal to the threshold value α (S307, No), the process of step S307 is determined again.

  Step S308: It is determined whether the generated power X of the solar panel 11 exceeds a predetermined threshold value β (corresponding to the “second threshold value” in the claims) smaller than the threshold value α. This determination is made to switch the mode at a timing (X ≦ β) different from that at the time when the generated power X of the solar panel 11 changes over the threshold value α. The threshold value β can be set to a point at which it is determined that the efficiency of using the generated power X of the solar panel 11 in the charge control system 1 is significantly reduced. For example, if the power consumed by the battery monitoring unit 15 is greater than the power generation X of the solar panel 11, there is no advantage in charging the generated battery X to the driving battery 13, so the battery monitoring unit 15 consumes the power. Power may be set as the threshold value β.

  If the generated power X exceeds the threshold value β (S308, Yes), the process proceeds to step S309 (process (2) in FIG. 4). On the other hand, when the generated power X does not exceed the threshold value β (S308, No), the process proceeds to step S310.

  Step S309: It is determined whether the accumulated generated energy S2 exceeds the accumulated generated energy S1. This determination is also made to switch the mode at a timing (S2> S1) different from that at the time when the generated power X of the solar panel 11 changes across the threshold value α. By comparing the accumulated power generation amount S1 with the accumulated power generation amount S2, it is possible to detect that the utilization efficiency has decreased in the charging process in the second mode.

  If the accumulated generated energy S2 exceeds the accumulated generated energy S1 (S309, Yes), the process proceeds to step S310 (process (3) in FIG. 4). On the other hand, when the accumulated generated energy S2 does not exceed the accumulated generated energy S1 (S309, No), the process returns to step S307.

  Step S310: The charge mode is switched from the second mode to the first mode. Thereby, the charging process in the first mode is performed. In the first charge control, the process A for charging the generated power X of the solar panel 11 to the solar battery 12 and the generated power X of the solar panel 11 and the power stored in the solar battery 12 are charged to the driving battery 13 The processing B is repeated according to the storage amount of the solar battery 12. When the charging mode is switched, the process proceeds to step S311.

  Step S311: The accumulated power generation amounts S1 and S2 are reset. When the accumulated power generation amount is reset, the process returns to step S301 for determining the charge mode.

<Second charge control>
FIG. 6 is a flow chart for explaining the processing procedure of the second charge control that the charge control unit 14 of the charge control system 1 executes. FIG. 7 is a diagram showing switching timing between the first mode and the second mode in the second charge control. FIG. 8 is a diagram showing a variation example of the generated power X in the charging process of the second mode.

  The second charge control shown in FIG. 6 is different from the first charge control shown in FIG. 3 described above in the processes of steps S601 to S607. Hereinafter, the second charge control will be described focusing on the different processing.

  Step S301: It is determined whether the charging mode currently being executed is the first mode or the second mode. If the charge mode is the first mode, the process proceeds to step S601. If the charge mode is the second mode, the process proceeds to step S306.

  Step S601: It is determined whether the generated power X of the solar panel 11 exceeds a predetermined threshold value γ (corresponding to the “third threshold value” in the claims) larger than the threshold value α. This determination is performed to determine whether the generated power X of the solar panel 11 satisfies the charge permitting power value, which is the minimum required power value for charging preset in the driving battery 13. . Therefore, threshold value γ can be set to this charge permitting power value.

  If the generated power X exceeds the threshold value γ (S601, Yes), the process proceeds to step S303. On the other hand, when the generated power X does not exceed the threshold value γ (S601, No), the process of step S601 is determined again.

  Step S303: It is determined whether or not a time T2 elapsed from the previous switching from the first mode to the second mode has reached a predetermined time T1. If the elapsed time T2 has reached the predetermined time T1 (S303, Yes), the process proceeds to step S602. On the other hand, if the elapsed time T2 has not reached the predetermined time T1 (S303, No), the process returns to step S601.

  Step S602: The charge mode is switched from the first mode to the second mode. Thereby, the charging process in the second mode is performed. In the second charge control, the drive battery 13 is directly charged with the power up to the threshold γ which is a part of the generated power X of the solar panel 11. When the charging mode is switched, the process proceeds to step S305.

  Step S306: Accumulation of accumulated power generation amounts S1 and S2 is started. When the accumulation of the accumulated power generation amount is started, the process proceeds to step S603.

  Step S603: It is determined whether the generated power X of the solar panel 11 is less than or equal to the threshold value γ. This determination is also made to determine whether or not the generated power X of the solar panel 11 satisfies the charge permission power value that is the minimum necessary for charging preset in the drive battery 13. If the generated power X is less than or equal to the threshold value γ (S603, Yes), the process proceeds to step S604 (range (4) in FIG. 7). On the other hand, if the generated power X exceeds the threshold value γ (S603, No), the process proceeds to step S605 (range (5) in FIG. 7).

Step S604: It is determined whether the storage amount SB _SOC of the solar battery 12 exceeds a predetermined lower limit value L or not. This determination is performed to avoid the state of charge SB _SOC of the solar battery 12 reaching an overdischarged state. Therefore, the lower limit value L is set based on the amount of stored power in the overdischarged state. If the storage amount SB _SOC exceeds the lower limit L (S604, Yes), the process proceeds to step S307. On the other hand, when the storage amount SB _SOC is equal to or less than the lower limit L (S604, No), the process proceeds to step S310.

  Step S307: It is determined whether the generated power X of the solar panel 11 has become equal to or less than the threshold value α. When the generated power X becomes equal to or less than the threshold value α (S307, Yes), the process proceeds to step S308. On the other hand, when the generated power X exceeds the threshold value α (S307, No), the process proceeds to step S607.

Step S605: It is determined whether the storage amount SB _SOC of the solar battery 12 is less than a predetermined upper limit value H. This determination is made to prevent the storage amount SB _SOC of the solar battery 12 from being overcharged. Therefore, the upper limit value H is set based on the amount of stored power in the overcharged state. If the storage amount SB _SOC is less than the upper limit value H (S605, Yes), the process proceeds to step S606. On the other hand, when the storage amount SB _SOC is equal to or larger than the upper limit value H (S605, No), the process returns to step S603.

Step S606: Of the generated power X of the solar panel 11, processing for storing the excess power exceeding the threshold value γ, ie, the remaining surplus power not directly charged to the driving battery 13 in the solar battery 12 (surplus charge storage) is performed Ru. As shown in FIG. 8, in the “surplus” period in which the generated power X exceeds the threshold value γ, the surplus power is stored in the solar battery 12 and the storage amount SB _SOC increases. When the surplus charge storage is performed, the process returns to step S603.

Step S607: Processing for discharging the power shortage from the solar battery 12 from the solar battery 12 and charging the drive battery 13 (short charge) in order to satisfy the power requirement of the threshold γ Will be implemented. As shown in FIG. 8, during the “insufficient” period in which the generated power X falls below the threshold value γ, power is brought out from the solar battery 12 to the driving battery 13 and the storage amount SB _SOC falls. When the shortfall charging is performed, the process returns to step S603.

<Modification example of charge control>
In the above steps S307, S308, S309, and S603, a lapse of a predetermined time (for example, one minute) is waited so that instantaneous switching of the charge mode does not occur with the fluctuation of the generated power X instantaneously. The determination may be made after that.

  Further, the magnitude of the generated power X of the solar panel 11 to be compared and determined in the above steps S302, S307, S308, S601 and S603 is obtained from the solar radiation intensity received by the solar panel 11 obtained by the solar radiation intensity acquisition means separately provided separately May be Further, the threshold value α to be compared and determined in step S302 and the threshold value α to be compared and determined in step S307 may be set to different values.

  In addition, the reset of the elapsed time T2 performed in step S305 and the start of re-measurement may be performed after switching to the first mode in step S310. In addition, in the comparison determination performed in step S303, instead of the time T2 when the switching of the charging mode has elapsed, the number of times of switching the charging mode may be used as the determination criterion.

  Further, in the comparison determination performed in step S308, instead of the threshold value β, the variation amount of the generated power X of the solar panel 11 within a certain time may be used as a determination criterion. Further, in the comparison determination performed in the step S308, the input / output current (power) of the accessory battery acquired by the accessory battery input / output current acquiring unit newly separately provided may be used as the judgment reference instead of the threshold value β. .

  Further, in the comparison determination performed in the above steps S306 and S309, the threshold α is used instead of the cumulative integration of the generated power X of the solar panel 11 that exceeds or is less than the threshold α for a predetermined period. You may use the time which cumulatively added the period which exceeded or became below as a judgment standard.

  Furthermore, when it is determined in step S302 or S307 that the threshold value α has been exceeded or is less than the threshold value in step S302 or S307 without performing the comparison determination in steps S303, S308, and S309, or the threshold value in step S601. When it is determined that γ has been exceeded, the charging mode may be switched immediately (steps S304, S602, or S310).

[Operation and effect in the present embodiment]
As described above, according to the charge control system 1 and the charge control method thereof according to one embodiment of the present invention, for example, the utilization efficiency of the generated power X is at least based on the magnitude of the generated power X of the solar panel 11. The first mode and the second mode are switched to improve. As a result, it is possible to prevent the charging of the drive battery 13 from being performed while the utilization efficiency of the generated power X is low. Further, since the second mode is performed, the number of processes for alternately charging and discharging the solar battery 12 in the first mode can be reduced.

  In addition, since the mode is not immediately switched even if the generated power X of the solar panel 11 changes over the threshold value α, the instantaneous fluctuation of the generated power X of the solar panel 11 frequently causes the first mode and the second mode to be frequent. Can be avoided (control chattering).

  In addition, if the lower limit power value at which the decrease in the generated power utilization efficiency of the solar panel 11 in the charge control system 1 is permitted is set as the threshold value β, the second mode is continued within the range where the decrease in utilization efficiency is permitted. Can be implemented. As a result, the number of processes for alternately charging and discharging the solar battery 12 in the first mode can be reduced.

  Further, even if the power generation efficiency of the solar panel 11 is judged to be significantly reduced based on the accumulated power generation amounts S1 and S2, even if the power generation power X of the solar panel 11 does not reach the threshold value β, from the second mode The charge mode can be switched to the first mode. Thereby, the number of processes for alternately charging and discharging the solar battery 12 in the first mode can be reduced, and the charging process in the second mode is prevented from being performed while the utilization efficiency of the generated power X is low. it can.

  In addition, the first mode can be continuously executed until the predetermined time T2 elapses even when the generated power X of the solar panel 11 exceeds the threshold value α. Thereby, it can be avoided that the first mode and the second mode are frequently switched due to the instantaneous fluctuation of the generated power X of the solar panel 11.

  In addition, when switched to the second mode, if the generated power X of the solar panel 11 exceeds the threshold γ, the driving battery 13 is directly charged with at least the threshold γ of the generated power X, and directly The remaining surplus power not to be charged can be charged to the solar battery 12. Thus, for example, in the case where the charge permission electric power value (threshold value γ) required at least for charging the driving battery 13 is set in advance, the threshold value γ of the generated power X of the solar panel 11 is It is possible to charge the solar battery 12 without waste for excess surplus power without waste.

At this time, in order to prevent the solar battery 12 from being overcharged, the surplus power is not charged when the storage amount SB _SOC of the solar battery 12 rises to a predetermined upper limit value H. It is preferable to do.

  In addition, when switched to the second mode, if the generated power X of the solar panel 11 does not exceed the threshold γ, all the generated power X is directly charged to the drive battery 13 and the insufficient power does not satisfy the threshold γ. A minute can be charged from the solar battery 12 to the drive battery 13. Thereby, for example, when the driving battery 13 sets the charge permission power value (threshold value γ) in advance, the insufficient power for which the generated power X of the solar panel 11 does not reach the threshold value Since the second mode can be continuously executed by taking it out and charging the driving battery 13, frequent switching between the first mode and the second mode can be avoided.

At this time, in order to prevent the solar battery 12 from being in an overdischarged state, it is preferable to switch to the first mode when the storage amount SB _SOC of the solar battery 12 falls to a predetermined lower limit L.

  The present invention is applicable to, for example, a charge control system that uses the generated power of a solar panel, such as a vehicle.

DESCRIPTION OF SYMBOLS 1 charge control system 11 solar panel 12 solar battery 13 drive battery 14 charge control part 14a solar ECU
14b Relay Circuit 15 Battery Monitoring Unit

Claims (10)

Solar panels that generate electricity from sunlight,
A first battery that can be charged and discharged,
A second battery that can be charged and discharged,
It is connected to the solar panel, the first battery, and the second battery, and the process of charging the first battery with the generated power of the solar panel and the power stored in the first battery indirectly to the second battery The first mode of repeatedly performing the process of charging according to the storage amount of the first battery, and the second mode of directly charging the generated power of the solar panel to the second battery are at least the generated power of the solar panel And a control unit that switches based on the
Charge control system. The control unit can switch the mode at a timing different from that at the time when the generated power of the solar panel changes across a first threshold at which a mode in which the utilization efficiency of the generated power becomes relatively high switches.
The charge control system according to claim 1. The control unit switches to the first mode when the generated power of the solar panel becomes equal to or less than a second threshold smaller than the first threshold while executing the second mode.
The charge control system according to claim 2. The control unit is configured to, while the generated power of the solar panel is between the first threshold and the second threshold and execute the second mode, an accumulated generated power amount exceeding the first threshold in a predetermined period is Switching to the first mode if the accumulated power generation amount does not exceed the first threshold value;
The charge control system according to claim 3. When the generated power of the solar panel exceeds the first threshold during execution of the first mode, the control unit switches to the second mode when a predetermined time has elapsed after switching the mode.
The charge control system according to claim 2. When the control unit switches to the second mode, if the generated power of the solar panel exceeds a third threshold larger than the first threshold, at least the third threshold of the generated power of the solar panel Charging the second battery directly with the power of the second battery, and charging the first battery with the remaining surplus power not directly charging the second battery;
The charge control system according to claim 5. The control unit charges the first battery with the surplus power if the storage amount of the first battery rises to a predetermined upper limit value even if the generated power of the solar panel exceeds the third threshold. Absent,
The charge control system according to claim 6. When the control unit switches to the second mode, if the power generated by the solar panel does not exceed a third threshold larger than the first threshold, the controller converts all of the power generated by the solar panel to the second battery. Directly charge the battery, and charge the second battery from the first battery with insufficient electric power less than the third threshold,
The charge control system according to claim 5. The control unit switches to the first mode if the storage amount of the first battery decreases to a predetermined lower limit value even if the generated power of the solar panel does not exceed the third threshold.
The charge control system according to claim 8. A charge control method executed by a control device that controls charging of a battery based on generated power of a solar panel generated by solar light,
A process of charging the first battery capable of charging and discharging the generated power of the solar panel, and a process of indirectly charging the second battery capable of charging and discharging the electric power stored in the first battery It has a first mode which is repeatedly performed according to the storage amount, and a second mode which directly charges the second battery with the generated power of the solar panel,
Switching between the first mode and the second mode based at least on the generated power of the solar panel,
Charge control method.

Images