JPH11243650A - Solar street light charging/discharging controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To compare a charged value with a fundamental lighting power value, calculate an insufficient power value or an excessive power value, control the discharge value so as to have the storage capacity of a battery constant, avoid the overcharging and overdischarging of a battery, improve the load utilization factor of an illumination light, and furthermore, realize a stable load operation in order to utilize solar generation which fluctuates substantially by the weather. SOLUTION: A charge value and a load power value are calculated by a current detection unit 10, which detects the charge current of a solar cell 2 and the load current of an illumination light 7. The charge value is compared with a predetermined basic lighting power value for calculating an insufficient power value or an excessive power value. IF the charged value is larger than a predetermined fundamental lighting power value, and furthermore, the insufficient integrated power value is zero, the load is increased. If the charge value is smaller than the predetermined basic lighting power value, the load illumination lights corresponding to the fundamental lighting power value are lit. The power control is practiced so as to fill the then insufficient power value with the excessive power value on days, when the charge value was larger than the fundamental lighting power value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charge / discharge control device for a solar street light, which controls charging and discharging of a solar street light by a combination of a storage battery, a solar cell, and an illumination light.

[0002]

2. Description of the Related Art A conventional control device for a solar street light uses a control device as shown in FIG.
FIG. 5 is a block circuit diagram of a charge / discharge control device for a solar street light. (2) a solar cell, (3) a backflow prevention diode, (4) a storage battery protection switch or element,
(5) is a storage battery, (6) is a switch or element for load connection, and (7) is an illumination lamp as a load. (8) is a storage battery voltage detection unit, and (9) is a solar cell voltage detection unit.
It is input to the charge / discharge control means of 6). (17) is a timer control unit based on the timer control signal of (18) (1).
6) is connected to the charge / discharge control means. (14) is a load connection control signal which is output from the charge / discharge control means of (16) and input to the load connection switch or element of (6). (15) is a storage battery protection control signal (1
It is outputted from the charge / discharge control means of 6) and inputted to the storage battery protection switch or element of 4).

The operation of the charge / discharge control device (1) having the above configuration will be described below. The storage battery protection switch or element (4), which is normally closed in FIG. 5, causes the storage battery to be charged by the charging current supplied from the solar battery, and the storage battery voltage detected by the storage battery voltage detection unit of (8) to be lower. When the battery voltage rises and reaches the overcharge voltage determined by the storage battery (5), the storage battery protection control signal (15) is output from the charge / discharge control means (16), and the storage battery protection switch or element (4) is opened. Stop charging. Also, a normally open load connection switch or element (6)
The load connection control signal (14) is output from the charge / discharge control means when the solar cell voltage detected by the solar cell voltage detection unit in (9) has dropped to a predetermined sunset voltage, and the load is closed, and the illumination lamp of the load is turned on. (7) lights up. At the same time, the timer control section (17) starts counting time, and after a lapse of a predetermined time, a timer control signal (18) is output, and the load connection switch or element (6) is opened by the charge / discharge control means, and the illumination lamp ( 6) goes out. When the load connection switch or the element (6) is closed, that is, when the illumination lamp (7) is turned on, when the discharge of the storage battery (5) progresses and drops to the overdischarge voltage determined by the storage battery, The load connection switch or element (6) opens and the illuminator (7) turns off.

As described above, in the conventional charge / discharge control device for a solar street light, a protection circuit for preventing overcharging and overdischarge of a storage battery and a control device for controlling a lighting time by a timer are widely used. In the discharge control device, if the setting of the lighting time is shortened in accordance with the amount of solar radiation in winter, it will be overcharged and the solar power generation will be cut off. It cannot be used, which is a great disadvantage for the user. In the case of a stand-alone solar street light, the size of the solar cell supported by the pole is limited, and the electric energy that can be generated is also limited. Furthermore, the amount of solar power generated daily varies greatly depending on the weather, so that it is necessary to control solar power generation effectively.

[0005]

According to the present invention, in order to make effective use of photovoltaic power generation, the amount of charge and the basic lighting power are compared, the amount of insufficient power or the amount of excess power is calculated, and the battery capacity of the storage battery is kept constant. Control the amount of discharge so that
An object of the present invention is to provide a charge / discharge control device for a solar street light that can avoid overdischarge, increase the load operation rate of an illumination lamp, and realize stable load operation.

[0006]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a method of charging a storage battery with electric energy obtained from a solar cell (2) via a backflow prevention diode (3) and a switch or element (4) for protecting the storage battery. A solar cell voltage detecting section (9) for detecting the solar cell voltage of the storage battery, a storage battery voltage detecting section (8) for detecting the voltage of the storage battery that fluctuates by charging and discharging, and charging the storage battery (5) from the solar battery (2). A current detecting unit (10) for detecting a charging current flowing at the time and a discharging current flowing to the illumination lamp (7) via a load connection switch or element (6) having means for increasing a load from the storage battery; CPU having a current amplification unit (11) for amplifying the voltage to be applied, and a constant voltage circuit unit (13) for producing a control power supply with a constant voltage from a storage battery whose voltage fluctuates by charging and discharging, and having a time measurement function. The control means (12) judges sunset and dawn from the solar cell voltage obtained by the solar cell voltage detection section (9), and determines the charge amount and the charge amount from the charge current and the discharge current obtained by the current detection means (10). Calculate the load power amount, compare the charged amount with the preset basic lighting power amount, calculate the insufficient power amount or surplus power amount, and find that the charging amount is larger than the basic lighting power amount and the shortage until the previous day. When the integrated power amount is zero, the illumination lamp (7) of the load is turned on so as to increase the load power amount by the surplus power amount, and when the charging amount is smaller than the basic lighting power amount, the basic lighting power amount In this case, the lighting lamp (7) of the load is turned on. The insufficient power amount at that time is added to the insufficient integrated power amount, and the load is replenished with the surplus power amount on the day when the charging amount is larger than the basic lighting power amount. Connection with means for increasing the load A solar street lamp charge and discharge control device for controlling the switch or element (6).

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments with reference to the drawings. FIG. 1 is a block circuit diagram of a charge / discharge control device for a solar street light according to the present invention. FIG.
In the above, the solar cell (2) is connected to the storage battery (5) via the backflow prevention diode (3) and the storage battery protection switch or element (4), and includes means for increasing the load connected to the storage battery (5). The load connection switch or element (6) is connected to an illumination lamp (7) as a load.

As means for increasing the load, the load connection switch or element (6) has two switches or elements, and the illumination lamp has a structure in which two lamps are put in one lamp. ing.

[0009] A solar cell voltage detector (9) for detecting the voltage of the solar cell and a storage battery voltage detector (8) for detecting the voltage of the storage battery are input to the CPU control means (12) and charged by the solar cell. A current detection unit (10) that detects a current and a load current of a lighting lamp is input to a current amplification unit (11) that amplifies a voltage corresponding to the current, and outputs a current measurement signal (1).
9) is connected to the CPU control means (12). The output of the CPU control means (12) is supplied to a load connection switch or element (6) having means for increasing the load and a load connection control signal (14) and a storage battery protection switch or element (4). Each is connected by a control signal (15).

The CPU control means (12) has a well-known configuration having a CPU, a storage device, an input / output interface, and an A / D converter. The constant voltage circuit section (13) controls a constant voltage from a storage battery whose voltage fluctuates by charging and discharging. A voltage control power supply is made, and a CPU control means (12) and a current amplification section (11)
To supply.

FIG. 2 is a timing chart showing the setting of the basic lighting pattern.
Represents time. The above description is based on the assumption that the basic lighting power amount of the illuminating lamp determined from the average annual sunshine time and the rated current of the solar cell used and the manner of lighting the illuminating lamp are the basic lighting pattern shown in FIG. The operation of the charge / discharge control device (1) having the above configuration will be described below.

FIG. 3 is a flowchart of the main routine of the CPU control means. The sunset detection determination unit (21) in FIG. 3 determines whether or not sunset has occurred. When the voltage of the solar cell voltage detection unit (9) is equal to or lower than the voltage at the time of sunset, it is determined that sunset. You. When the sunset detection determining unit (21) determines that it is not sunset, that is, in the case of NO, the charging control is performed, and the storage battery (5) is charged with the current supplied from the solar battery (2). Next, the process proceeds to an overcharge determination section (22), where it is determined whether or not overcharge has occurred. The overcharge is determined when the charging proceeds and the voltage of the storage battery voltage detector (8) rises to the overcharge voltage determined by the storage battery (5), and the overcharge is determined by the overcharge determination unit (22). Not charging,
That is, if NO, after a lapse of a predetermined time at the reference time (23), the process proceeds to the charge amount calculation process (24), and the value of the charge current of the solar cell multiplied by the charge / discharge coefficient of the storage battery detected by the current detection unit (10) is obtained. The value is stored in the charge amount register, and the process returns to the sunset detection determining unit (21). Therefore, the determination unit for sunset detection (21)
The process is repeated until sunset is detected, so the charge amount that day is stored in the charge amount register. If the overcharge determination section (22) determines that the battery is overcharged, that is, if YES, the process proceeds to the overcharge process (25), and the normally closed battery protection switch or element (4) is opened. To set the charging prohibition state, and store the preset maximum charging amount in the charging amount register. The charging prohibition state is released when it is determined that the sunset is detected by the sunset detection determination unit (21).

When the sunset detection judging section (21) detects sunset, that is, when YES, discharge control is performed. In the discharge control, first, the power shortage flag is turned off as a process of control preparation (26), and the basic lighting power amount is stored in the power shortage register in order to know the power shortage when the charged amount is smaller than the basic lighting power amount. Then, the process proceeds to the step processing of lighting the illumination lamp according to the basic lighting pattern described above.

The step process is a process in which the time from the start of lighting of the basic lighting pattern to the end of lighting is divided into several steps, the lighting time and the lighting amount are set in the steps, and the steps are sequentially executed. One step includes a step setting, a dimming determination process (28), and a lighting control subroutine (29). (27a)
In the setting of step 1, the lighting time and the lighting amount of the basic lighting pattern are set, and the processing of the lighting control subroutine of (29) is performed. Before that, the dimming determination processing of (28) is performed. The dimming determination process is performed when the lighting amount of the step is not the maximum, for example, when the lighting amount is one electric lamp or 50%, the shortage control flag is OFF, and the charging amount exceeds a predetermined charging amount. As shown in FIG. 5B, the lighting amount in the step setting is changed so as to increase the lighting amount, and when the shortage control flag is ON, the lighting amount is not changed.

FIG. 4 shows the processing of the lighting control subroutine.
First, in the output processing of (41), the lighting amount set in the step setting and the dimming determination processing is output to the load connection switch or element (6), and the illumination lamp (7) is turned on. Next, after a lapse of a predetermined time at the reference time (23), the process proceeds to the discharge amount calculation process (43), and the load current detected by the current detection unit (10) is subtracted from the charge amount of the charge amount register described above to charge again. Store in quantity register. Next, the process proceeds to the charge amount determination unit (44), and when the calculation result obtained by subtracting the load current from the charge amount in the charge amount register is “negative”, that is, when the result is NO, the power shortage flag is turned on, and the charge amount register Set the charge amount to zero and proceed to time-up determination (50).
When the result of subtracting the load current from the charge amount in the charge amount register by the charge amount determination unit (44) is “positive” or zero, that is, when YES, the operation unit (4)
Proceeding to 7), the result obtained by subtracting the load current from the power shortage register is stored again in the power shortage register. Next, when the result of subtracting the load current from the power shortage register is "negative", that is, when the result of the determination is negative, the value of the power shortage register is set to zero, and the determination of the time-up in step (50) is made. If NO, the process directly proceeds to the time-up determination (50). The time-up determination (50) is a portion for determining whether or not the lighting time set in the step setting has ended. Is not completed, that is, if NO, the process returns to the reference time (42). Therefore, when the charged amount becomes zero during the processing of the lighting control subroutine, the insufficient power calculation processing (4
Since 7) is not performed, the value of the power shortage register remains and the amount of power shortage is known. Further, when there is a charge amount in the charge amount register, the determination of time-up is YES, and when returning to the main routine, the charge amount becomes the surplus power amount.

In the above-described step processing, after the end of the last step processing composed of the subroutines of step setting, dimming determination processing, and lighting control, the process proceeds to the power shortage flag determination (30) in FIG. In the lighting control subroutine, it is determined whether or not the power shortage flag has been turned ON. If the power shortage flag is ON and the power shortage occurs, that is, if YES, the shortage control flag is turned ON in steps (35) and (36), and the value of the power shortage register is added to the power shortage integrated power register to turn off the light. Proceed to (37),
When the power shortage determination unit (30) determines that the power shortage flag is OFF and there is a surplus power amount, that is, NO, the surplus power amount is subtracted from the shortage integrated power amount register, and the determination unit (3)
Proceed to 2). When the result obtained by subtracting the surplus power from the shortage integrated power amount register is “positive” and there is still a shortage of power, that is, when the determination is NO, the determination unit (32) proceeds to the light-off process (37). In the case where the calculation result is “negative” or zero in (32) and the power shortage is eliminated,
That is, when YES, the shortage control flag is turned off,
The lighting time extension process of (34) is executed.

The lighting time extension process shown in FIG. 5C is performed by the reference time (23) by the absolute value of the result obtained by subtracting the surplus power from the insufficient integrated power register of (31).
Each time, the load current is subtracted, the illumination lamp (7) is turned on until the surplus power becomes zero, and the process proceeds to the turn-off process (30). Open, turn off the illumination lamp, and proceed to night light detection (38).
The dawn detection determination section is a section that determines whether or not dawn has occurred. When the voltage of the solar cell voltage detection section (9) becomes equal to or higher than the dawn voltage, it is determined to be dawn, and the detection is performed until it is determined to be dawn. When the dawn is detected, the process returns to the sunset detection (21) to start the charging control again.

[0018]

The present invention is constructed and controlled as described above, and has the following effects.

Since a current detector for detecting the charging current supplied from the solar cell and the load current of the illuminating lamp is provided, the charge amount and the discharge amount can be monitored. If there is a large amount and the accumulated energy shortage is zero,
By controlling to increase the power amount of the load by the surplus power amount, overcharging can be avoided and the operating rate of the load can be increased.

If the charging amount is smaller than the set basic lighting power amount, the lighting lamp of the load is turned on by the basic lighting power amount. At this time, the insufficient power amount is larger than the basic lighting power amount. Overdischarge is avoided by the control of replenishment with the surplus electric energy of the day, and stable load operation can be realized.

In addition, even if the sunless day continues to some extent, the insufficient integrated power amount is monitored and supplemented with surplus power, so that the battery capacity is recovered. As described above, the photovoltaic power generation can be effectively used by controlling the battery capacity of the storage battery to be constant.

[Brief description of the drawings]

FIG. 1 is a block circuit diagram of a solar street light charge / discharge control device according to an embodiment.

FIG. 2 is a timing chart illustrating setting of a basic lighting pattern according to the embodiment.

FIG. 3 is a flowchart of a main routine of a CPU control unit of the embodiment.

FIG. 4 is a flowchart of a lighting control subroutine of a CPU control unit of the embodiment.

FIG. 5 is a block circuit diagram of a conventional solar street light charge / discharge control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Charge / discharge control device 2 Solar cell 3 Backflow prevention diode 4 Storage battery protection switch or element 5 Storage battery 6 Load connection switch or element 7 Illumination lamp 8 Battery voltage detection unit 9 Solar cell voltage detection unit 10 Current detection unit 11 Current amplification unit 12 CPU control unit 13 Constant voltage circuit unit 14 Load connection control signal 15 Storage battery protection control signal 16 Charge / discharge control unit 17 Timer control unit 18 Timer control signal 19 Current measurement signal

Claims (1)

[Claims] 1. A solar cell voltage for detecting a solar cell voltage when electric energy obtained from a solar cell (2) is charged to a storage battery via a backflow prevention diode (3) and a storage battery protection switch or element (4). A detection unit (9); a storage battery voltage detection unit (8) for detecting a voltage of the storage battery that fluctuates due to charging / discharging; a charging current flowing when charging the storage battery (5) from the solar battery (2); and a load from the storage battery. A current detector (10) for detecting a discharge current flowing through the illumination lamp (7) via a load connection switch or element (6) having a means for increasing the current, and a current amplifier (11) for amplifying a voltage corresponding to the current. ) And a constant voltage circuit unit (1) that generates a control power supply with a constant voltage from a storage battery whose voltage fluctuates due to charging and discharging.
3) The CPU control means (12) having a time measurement function determines sunset and dawn from the solar cell voltage obtained by the solar cell voltage detection section (9), and determines whether the current detection section (10 ), The charge amount and the load power amount are calculated from the charge current and the discharge current obtained, and the charge amount is compared with a preset basic lighting power amount to calculate an insufficient power amount or an excess power amount. Is larger than the basic lighting power amount and the shortage integrated power amount up to the previous day is zero, the load lamp (7) is turned on so as to increase the load power amount by the surplus power amount, and the charging amount is reduced. If less than the basic lighting power, the lighting of the load by the basic lighting power (7)
For the load connection, there is a means for increasing the load so that the insufficient power amount at that time is added to the insufficient integrated power amount and the amount of charge is supplemented with the surplus power amount on the day when the charge amount is larger than the basic lighting power amount. A charge / discharge control device for a solar street light, characterized by controlling a switch or an element (6).