JP6953997B2 - Charge control system and charge control method - Google Patents

Description

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

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

Japanese Unexamined Patent Publication No. 2014-007937

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

Further, the process of alternately charging and discharging the solar battery affects the durability and 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 in the system to increase the number of processes in which the battery is charged and discharged alternately.

The present invention has been made in view of the above problems, and is 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 power of a solar panel. The purpose is to provide.

In order to solve the above problems, one aspect of the present invention includes 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, a solar panel, a first battery, and the like. The process of charging the first battery with the power generated by the solar panel connected to the second battery and the process of indirectly charging the second battery with the power stored in the first battery are repeated according to the amount of electricity stored in the first battery. It is characterized by including a control unit that switches between the first mode to be performed and the second mode for directly charging the generated power of the solar panel to the second battery 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 at least based on the generated power of the solar panel. As a result, it is possible to prevent the battery from being charged while the utilization efficiency of the generated power is low. Further, since the second mode is executed, the number of times of the process of alternately charging and discharging the first battery in the first mode can be reduced.

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

In the above control, even if the generated power of the solar panel changes across the first threshold value, the mode is not immediately switched. Therefore, the first mode and the second mode are frequently switched due to the momentary fluctuation of the generated power of the solar panel. It is possible to avoid switching (control chattering).

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

In the above control, the second mode can be continuously executed by setting the second threshold value to the lower limit power value at which the decrease in the power generation efficiency of the solar panel in the charge control system is allowed. .. This makes it possible to reduce the number of processes for alternately charging and discharging the first battery in the first mode.

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

In the above control, even if the generated power of the solar panel does not reach the lower limit power value, if it is determined that the power generation efficiency of the solar panel has significantly decreased based on the cumulative generated power amount, the second mode to the first You can switch the charging mode to mode. As a result, it is possible to reduce the number of processes for alternately charging and discharging the first battery in the first mode, and it is possible to prevent the charging process in the second mode from being performed while the power generation efficiency is low.

Further, in the above aspect, when the generated power of the solar panel exceeds the first threshold value while the first mode is being executed, the control unit switches to the second mode when a predetermined time elapses after switching the mode. You may.

According to the above control, even if the generated power of the solar panel exceeds the first threshold value, the first mode can be continuously executed until a predetermined time elapses. As a result, it is possible to prevent the first mode and the second mode from being frequently switched due to the momentary fluctuation of the generated power of the solar panel.

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

According to the above control, for example, when the second battery sets the minimum required power value for charging, the generated power of the solar panel is the predetermined power value (= third threshold value). When the amount exceeds, the first battery is charged with the surplus power amount exceeding the predetermined power value (third threshold value) while executing the second mode. As a result, there is no waste of generated power such as discarding surplus power.

At this time, the control unit does not charge the first battery with the surplus power when the stored power of the first battery rises to a predetermined upper limit value even if the generated power of the solar panel exceeds the third threshold value. Can be done. 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 the control unit switches to the second mode, if the generated power of the solar panel does not exceed the third threshold value, the control unit directly charges the second battery with all the generated power of the solar panel. In addition, the second battery may be charged with the insufficient electric power that is less than the third threshold value.

According to the above control, for example, when the second battery sets a predetermined minimum power value required for charging, the generated power of the solar panel is a predetermined power value (= third threshold value). When the value falls below the above value, the shortage of power less than the predetermined power value (third threshold value) is taken out from the first battery and charged to the second battery to continue the execution of the second mode. As a result, it is possible to prevent the second mode from being immediately switched to the first mode, and it is possible to prevent the first mode and the second mode from being frequently switched.

At this time, the control unit can switch to the first mode when the amount of electricity stored in the first battery drops to a predetermined lower limit even if the generated power of the solar panel does not exceed the third threshold value. By this control, it is possible to prevent the first battery from being discharged below the lower limit value and becoming an over-discharged state.

Further, each process performed by the control unit of the charge control system described above can be regarded as a charge control method for giving a series of processing procedures. This method is provided in the form of a program that causes a computer to perform a series of processing procedures. The program may be installed in a computer in the form of being 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 in which the battery is charged and discharged alternately while suppressing the decrease in the utilization efficiency of the generated power of the solar panel.

The figure which shows the structural example of the charge control system which concerns on one Embodiment of this invention. Diagram showing the relationship between the power generated by solar panels and the efficiency of system utilization A flowchart illustrating a first charge control processing procedure executed by the charge control unit. The figure which shows the mode switching timing in the 1st charge control The figure which shows the fluctuation example of the generated power in the charge processing of the 2nd mode A flowchart illustrating a second charge control processing procedure executed by the charge control unit. The figure which shows the mode switching timing in the 2nd charge control The figure which shows the fluctuation example of the generated power in the charge processing of the 2nd mode

[Overview]
In the charge control system and charge control method using the solar panel of the present invention, the battery is switched 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. As a result, it is possible to prevent the battery from being charged 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 main 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, the wiring through which electric power flows is shown by a solid line, and the wiring through which control signals other than electric power flow is shown by a broken line.

The solar panel 11 is, for example, a solar cell module that generates electricity by being irradiated with sunlight. The amount of power generated by the solar panel 11 depends on the intensity of solar radiation. The electric 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 a chargeable and dischargeable power storage element such as a lead storage battery or a nickel hydrogen battery. The solar battery 12 is connected to the charge control unit 14 so that it can be charged by the electric power generated by the solar panel 11 and can discharge the electric power stored by itself to the drive battery 13. The solar battery 12 corresponds to the "first battery" in the claims.

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

The battery monitoring unit 15 is configured to be able to monitor the stored 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, which will be described later, and the storage amount (SOC) of the drive battery 13 is supplied. Can be monitored.

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

The charging process in the first mode is the process A of 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 into the driving battery 13. This is a process in which the charging process B is repeated according to the amount of electricity stored in the solar battery 12. Specifically, the process A is performed until the stored amount of the solar battery 12 reaches a predetermined upper limit value, and then the process B is performed until the stored amount of the solar battery 12 reaches a predetermined lower limit value. Will be done. That is, the charging process in this first mode is a process of indirectly charging the generated power X of the solar panel 11 to the drive battery 13 via the solar battery 12.

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

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

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

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

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

<First charge control>
FIG. 3 is a flowchart illustrating a processing procedure of the first charge control executed by the charge control unit 14 of the charge control system 1. FIG. 4 is a diagram showing a switching timing between the first mode and the second mode in the first charge control. FIG. 5 is a diagram showing an example of fluctuation 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, turning on the power, and is repeatedly executed until the charge control system 1 is stopped by, for example, turning off the power.

Step S301: It is determined whether the charging mode currently being executed is the first mode or the second mode. As the charging mode immediately after the charge control system 1 is operated, for example, either the first mode or the second mode may be set as the default in advance, or the generated power X of the solar panel 11 immediately after the operation may be set. It may be determined based on. When the charging mode is the first mode, the process proceeds to step S302. When the charging 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 the threshold value α whose utilization efficiency is relatively higher in the second mode than in the first mode. When 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 the time T2 elapsed since the previous switching from the first mode to the second mode has reached the predetermined time T1. This determination is made to switch the mode at a timing (T2 ≧ T1) different from that when the generated power X of the solar panel 11 changes across the threshold value α. The predetermined time T1 drives, for example, a process of charging the solar battery 12 with the generated power X executed in the first mode and driving the power stored in the solar battery 12, which is determined based on the generated power X of the solar panel 11. The time required for the process of charging the solar panel 13 can be set.

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

Step S304: The charging mode is switched from the first mode to the second mode. As a result, the charging process in the second mode is executed. In the first charge control, all of 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 the time counting of the elapsed time T2 is newly started. When the timekeeping is newly started, the process returns to step S301 for determining the charging mode.

Step S306: Accumulation of cumulative power generation amounts S1 and S2 is started. As shown in FIG. 5, the cumulative power generation amount S1 is the amount of the power generation power X of the solar panel 11 that exceeds the threshold value α and is cumulatively integrated for a predetermined period. Further, as shown in FIG. 5, the cumulative power generation amount S2 is an amount obtained by cumulatively integrating the power portion of the power generation power X of the solar panel 11 that is equal to or less than the threshold value α for a predetermined period. When the accumulation of the cumulative 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 the threshold value α whose 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 equal to or less than the threshold value α (S307, No), the process of step S307 is determined again.

Step S308: It is determined whether or not 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 when the generated power X of the solar panel 11 changes across the threshold value α. The threshold value β can be set at a point where 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 battery monitoring unit 15 consumes more power than the generated power X of the solar panel 11, there is no advantage in charging the driving battery 13 with the generated power X, so that the battery monitoring unit 15 consumes the power. Power may be set as the threshold β.

When 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 or not the cumulative power generation amount S2 exceeds the cumulative power generation amount S1. This determination is also made to switch the mode at a timing (S2> S1) different from that when the generated power X of the solar panel 11 changes across the threshold value α. By comparing the cumulative power generation amount S1 and the cumulative power generation amount S2, it is possible to detect that the utilization efficiency has decreased in the charging process in the second mode.

When the cumulative power generation amount S2 exceeds the cumulative power generation amount S1 (S309, Yes), the process proceeds to step S310 (process (3) in FIG. 4). On the other hand, when the cumulative power generation amount S2 does not exceed the cumulative power generation amount S1 (S309, No), the process returns to step S307.

Step S310: The charging mode is switched from the second mode to the first mode. As a result, the charging process in the first mode is executed. In the first charge control, the drive battery 13 is charged with the process A of 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. Process B is repeated according to the amount of electricity stored in the solar battery 12. When the charging mode is switched, the process proceeds to step S311.

Step S311: Cumulative generated power amounts S1 and S2 are reset. When the cumulative power generation amount is reset, the process returns to step S301 for determining the charging mode.

<Second charge control>
FIG. 6 is a flowchart illustrating a second charge control processing procedure executed by the charge control unit 14 of the charge control system 1. FIG. 7 is a diagram showing a switching timing between the first mode and the second mode in the second charge control. FIG. 8 is a diagram showing an example of fluctuation 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 with a focus on this different process.

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

Step S601: It is determined whether or not 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 made to determine whether or not the generated power X of the solar panel 11 satisfies the charge permitted power value, which is the minimum power value required for charging in the drive battery 13. .. Therefore, the threshold value γ can be set to this charge permitted power value.

When 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 the time T2 elapsed since the previous switching from the first mode to the second mode has reached the predetermined time T1. When the elapsed time T2 reaches the predetermined time T1 (S303, Yes), the process proceeds to step S602. On the other hand, when the elapsed time T2 has not reached the predetermined time T1 (S303, No), the process returns to step S601.

Step S602: The charging mode is switched from the first mode to the second mode. As a result, the charging process in the second mode is executed. In the second charge control, the electric power up to the threshold value γ, which is a part of the generated electric 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 S306: Accumulation of cumulative power generation amounts S1 and S2 is started. When the accumulation of the cumulative power generation amount is started, the process proceeds to step S603.

Step S603: It is determined whether or not the generated power X of the solar panel 11 is equal to or less than 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 minimum charge permitted power value required for charging preset in the drive battery 13. When the generated power X is equal to or less than the threshold value γ (S603, Yes), the process proceeds to step S604 (range (4) in FIG. 7). On the other hand, when 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 or not the stored amount SB SOC} of the solar battery 12 exceeds the predetermined lower limit value L. _{This determination is made in order to prevent the stored amount SB SOC} of the solar battery 12 from reaching an over-discharged state. Therefore, the lower limit value L is set based on the amount of electricity stored in the over-discharged state. When the stored amount SB _SOC exceeds the lower limit value L (S604, Yes), the process proceeds to step S307. On the other hand, when the stored amount SB _SOC is equal to or less than the lower limit value L (S604, No), the process proceeds to step S310.

Step S307: It is determined whether or not the generated power X of the solar panel 11 is 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 or not the stored amount SB SOC} of the solar battery 12 is less than a predetermined upper limit value H. This determination is made in order to prevent _{the stored amount SB SOC} of the solar battery 12 from reaching an overcharged state. Therefore, the upper limit value H is set based on the amount of electricity stored in the overcharged state. When the stored 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 stored amount SB _SOC is equal to or higher 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, the power exceeding the threshold value γ, that is, the remaining surplus power that is not directly charged to the drive battery 13 is stored in the solar battery 12 (surplus power storage). NS. As shown in FIG. 8, during 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 stored amount SB _SOC increases. When the surplus electricity is stored, the process returns to step S603.

Step S607: A process of discharging the insufficient electric power in the generated electric power X of the solar panel 11 from the solar battery 12 and charging the drive battery 13 in order to satisfy the electric power portion of the threshold value γ (insufficient charge). Is carried out. As shown in FIG. 8, during the “insufficient” period in which the generated power X is below the threshold value γ, power is taken out from the solar battery 12 to the drive battery 13 and the stored amount SB _SOC decreases. When the insufficient charge is performed, the process returns to step S603.

<Modification example of charge control>
In steps S307, S308, S309, and S603, the elapse of a predetermined time (for example, 1 minute) is awaited so that the charging mode is not momentarily switched due to the momentary fluctuation of the generated power X. You may make a decision after that.

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

Further, the reset of the elapsed time T2 and the start of recounting performed in step S305 may be performed after switching to the first mode in step S310. Further, in the comparative determination performed in step S303, the number of times the charging mode is switched may be used as the determination criterion instead of the time T2 at which the charging mode switching has elapsed.

Further, in the comparative determination performed in step S308, instead of the threshold value β, the amount of fluctuation of the generated power X of the solar panel 11 within a certain period of time may be used as the determination criterion. Further, in the comparative determination performed in step S308, instead of the threshold value β, the input / output current (power) of the auxiliary battery acquired by the newly provided auxiliary battery input / output current acquisition means may be used as the determination criterion. ..

Further, in the comparative determination performed in steps S306 and S309, the threshold value α is set instead of the amount of the power generation power X of the solar panel 11 that exceeds or is equal to or less than the threshold value and is cumulatively integrated for a predetermined period. The time obtained by accumulating the period exceeding or decreasing may be used as a criterion.

Further, at the time when it is determined in step S302 or S307 that the threshold value α has been exceeded or has been exceeded or equal to or less than the threshold value α without performing the comparative determination in steps S303, S308, and S309, or in step S601. When it is determined that the threshold value has been exceeded, the charging mode may be switched immediately (steps S304, S602, or S310 described above).

[Action / effect in this embodiment]
As described above, according to the charge control system 1 and the charge control method thereof according to the embodiment of the present invention, for example, the utilization efficiency of the generated power X is based on at least the magnitude of the generated power X of the solar panel 11. Switch between the first mode and the second mode to improve. As a result, it is possible to prevent the drive battery 13 from being charged while the utilization efficiency of the generated power X is low. Further, since the second mode is executed, the number of times of processing in which the solar battery 12 is alternately charged and discharged by the first mode can be reduced.

Further, since the mode is not immediately switched even if the generated power X of the solar panel 11 changes across the threshold value α, the first mode and the second mode are frequently performed due to the momentary fluctuation of the generated power X of the solar panel 11. It is possible to avoid switching to (control chattering).

Further, if the lower limit power value at which the decrease in the power generation power utilization efficiency of the solar panel 11 in the charge control system 1 is allowed is set as the threshold value β, the second mode is continued within the range where the decrease in the utilization efficiency is allowed. Can be executed. This makes it possible to reduce the number of processes in which the solar battery 12 is alternately charged and discharged in the first mode.

Further, even if the generated power X of the solar panel 11 does not reach the threshold value β, if it is determined that the power generation efficiency of the solar panel 11 is significantly reduced based on the cumulative generated power amounts S1 and S2, the second mode is started. The charging mode can be switched to the first mode. As a result, the number of processes for alternately charging and discharging the solar battery 12 in the first mode can be reduced, and it is possible to prevent the charging process in the second mode from being performed while the utilization efficiency of the generated power X is low. can.

Further, even if the generated power X of the solar panel 11 exceeds the threshold value α, the first mode can be continuously executed until the predetermined time T2 elapses. As a result, it is possible to prevent the first mode and the second mode from being frequently switched due to the momentary fluctuation of the generated power X of the solar panel 11.

Further, when the mode is switched to the second mode, if the generated power X of the solar panel 11 exceeds the threshold value γ, at least the power portion of the generated power X having the threshold value γ is directly charged to the drive battery 13 and directly. The remaining uncharged surplus power can be charged to the solar battery 12. As a result, for example, when the drive battery 13 presets the minimum charge permission power value (threshold γ) required for charging, the threshold γ of the generated power X of the solar panel 11 is set. The surplus electric power that exceeds the amount can be charged to the solar battery 12 without waste without wasting it.

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

Further, when the mode is switched to the second mode, if the generated power X of the solar panel 11 does not exceed the threshold value γ, the entire generated power X is directly charged to the drive battery 13, and the insufficient power is less than the threshold value γ. Minutes can be charged from the solar battery 12 to the drive battery 13. As a result, for example, when the drive battery 13 has a charge permission power value (threshold γ) set in advance, the insufficient power portion in which the generated power X of the solar panel 11 is less than the threshold γ is reduced from the solar battery 12. Since the second mode can be continuously executed by taking it out and charging the drive battery 13, it is possible to avoid frequent switching between the first mode and the second mode.

At this time, in order to prevent the solar battery 12 from being over-discharged, it is preferable to switch to the first mode when _{the stored amount SB SOC of the solar battery 12 drops to a predetermined lower limit value L.}

The present invention can be used in a charge control system that utilizes the generated power of a solar panel, for example, a vehicle.

1 Charge control system 11 Solar panel 12 Solar battery 13 Drive battery 14 Charge control unit 14a Solar ECU
14b Relay circuit 15 Battery monitoring unit

Claims (7)

Solar panels that generate electricity with sunlight and
The first battery that can be charged and discharged and
A second battery that can be charged and discharged,
A process of charging the first battery with the generated power of the solar panel connected to the solar panel, the first battery, and the second battery, and indirectly charging the power stored in the first battery to the second battery. The first mode in which the charging process is repeated according to the amount of electricity stored in the first battery, and the second mode in which the generated power of the solar panel is directly charged to the second battery are set to at least the generated power of the solar panel. Equipped with a control unit that switches based on
The control unit
When the generated power of the solar panel changes across the first threshold value at which the mode in which the utilization efficiency of the generated power becomes relatively high is switched, the mode can be switched at a timing different from that time.
If the generated power of the solar panel becomes equal to or less than the second threshold value smaller than the first threshold value during the execution of the second mode, the mode is switched to the first mode.
While the generated power of the solar panel is between the first threshold value and the second threshold value and the second mode is being executed, the cumulative generated power amount exceeding the first threshold value in a predetermined period exceeds the first threshold value. If it is lower than the cumulative power generation amount, the mode is switched to the first mode.
Charge control system. When the generated power of the solar panel exceeds the first threshold value while the first mode is being executed, the control unit switches to the second mode if a predetermined time elapses after switching the mode.
The charge control system according to claim 1. When the control unit switches to the second mode, if the generated power of the solar panel exceeds a third threshold value larger than the first threshold value, at least the third threshold value of the generated power of the solar panel is exceeded. The second battery is directly charged, and the remaining surplus power that is not directly charged is charged to the first battery.
The charge control system according to claim 2. Even if the generated power of the solar panel exceeds the third threshold value, the control unit charges the first battery with the surplus power if the stored amount of the first battery rises to a predetermined upper limit value. No,
The charge control system according to claim 3. When the control unit switches to the second mode, if the generated power of the solar panel does not exceed the third threshold value larger than the first threshold value, the entire generated power of the solar panel is used as the second battery. The first battery charges the second battery with the insufficient electric power that does not meet the third threshold value.
The charge control system according to claim 2. The control unit switches to the first mode if the amount of electricity stored in the first battery drops to a predetermined lower limit even if the generated power of the solar panel does not exceed the third threshold value.
The charge control system according to claim 5. It is a charge control method executed by a control device that controls charging of the battery based on the generated power of the solar panel that generates electricity with sunlight.
The process of charging the first battery capable of charging and discharging the generated power of the solar panel and the process of indirectly charging the second battery capable of charging and discharging the power stored in the first battery are performed by the first battery. It has a first mode that repeats according to the amount of electricity stored, and a second mode that directly charges the second battery with the generated power of the solar panel.
A step of switching between the first mode and the second mode based on at least the generated power of the solar panel is provided .
In the above step
When the generated power of the solar panel changes across the first threshold value at which the mode in which the utilization efficiency of the generated power becomes relatively high is switched, the mode can be switched at a timing different from that time.
If the generated power of the solar panel becomes equal to or less than the second threshold value smaller than the first threshold value during the execution of the second mode, the mode is switched to the first mode.
While the generated power of the solar panel is between the first threshold value and the second threshold value and the second mode is being executed, the cumulative generated power amount exceeding the first threshold value in a predetermined period exceeds the first threshold value. If it is lower than the cumulative power generation amount, the mode is switched to the first mode.
Charge control method.

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