KR101035705B1 - Control device for battery charge and dischage using sunlight - Google Patents

Abstract

PURPOSE: A device for controlling the charging/discharging of a battery using solar light is provided to prevent rush currents with additional work and costs, thereby preventing a charging/discharging switch, a battery, and a DC load from being damaged. CONSTITUTION: A device for controlling the charging/discharging of a battery using solar light comprises a solar light module(11), a DC-DC converter, and a microcomputer(30). The solar light module converts insolation into DC power. The DC-DC converter boosts or lowers the ununiform DC power of the solar light module. The microcomputer charges the battery by the DC power.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a control device for a solar battery,

The present invention relates to a battery charge / discharge control device using solar light.

Instead of fossil energy that emits greenhouse gases, research and development on clean energy has progressed, and solar power generation and wind power generation are emerging as future energy sources that can replace fossil energy.

A solar power generation system using solar light includes a solar module for converting the solar radiation amount of solar light into direct current power; A DC-DC converter for boosting or reducing the irregular output DC power of the solar module to a DC power of a predetermined magnitude; And a microcomputer for controlling the DC-DC converter to charge and store the boosted or reduced output DC power in the battery, and to discharge the charged DC power from the battery to the DC load. Or an inverter that converts DC power supplied from the battery of the charge / discharge control device into AC power and supplies the AC power to the power system or supplies the AC power to the AC load.

The micom of the solar power generation system uses the A / D converter, the maximum power point tracking (MPPT) algorithm, and the PWM switching scheme to the DC-DC converter to keep the load output power constant .

As a known example of the above-described solar module and charge / discharge control device, Korean Patent Registration No. 10-0698355 (charge / discharge control system for independent type wind power generation in which pulses are alternately pulse-charged in a plurality of batteries) And Korean Patent No. 10-0454896 (charge / discharge control system for solar street lamps and independent modules for independent photovoltaic power generation, hereinafter referred to as prior art 2).

These patents have the following problems as the charging / discharging control system of the voltage chopping control method at the upper end of the DC link.

1, the conventional technique 1 is a voltage chopping control method using a charge / discharge switch at the upper end of a DC link, which is a (+) terminal of a photovoltaic module, so that the excessive inrush current at the time of charging damages the charge switch and the battery In the prior art 2, referring to FIG. 1, although a fuse is installed for interrupting the inrush current, if the fuse is cut off due to inrush current, it can not be restored. There was a troublesome problem to be done.

Second, since the input voltage and the input current range of the prior art 1 and 2 are fixed at 12V DC, the DC input voltage and the input current of the photovoltaic module are limited, so that the battery charge / discharge control It is difficult to provide a device.

Third, in the prior arts 1 and 2, when the battery is completely discharged during the low period of the rainy season during the rainy season, the power to the microcomputer controlling the charge / discharge control device is shut down to disable the charge / discharge function. Since the battery is used, the volume of the charge / discharge control system becomes large, so that miniaturization can not be achieved.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems of the conventional art described above, to prevent an inrush current without incurring additional work and costs, to simultaneously or individually drive DC loads of various electrical characteristics, Discharge control of the solar battery in order to prevent overcharge of the battery and damage of the DC load in addition to the prevention of the complete discharge of the battery.

The present invention relates to a solar module for converting solar radiation amount of sunlight into direct current power and outputting the same; A DC-DC converter for boosting or reducing the irregular output DC power of the solar module to a DC power of a predetermined magnitude; This DC-DC converter is controlled by an A / D converter, a maximum power follow-up (MPPT) algorithm and a PWM switching method to keep the load output power constant, and the boosted or stepped output DC power is charged and stored in the battery. A solar battery charge / discharge control device comprising a microcomputer for discharging a charged DC power from a battery and providing the charged DC power to a DC load, the solar battery charge / discharge control device comprising a microcomputer connected in parallel between a (+ A first voltage sensor for outputting a value to the microcomputer; A first inductor for preventing reverse current flow and rectification, a first inductor for preventing an inrush current during charging, a first switch controlled by a microcomputer, which is connected in series to the (+) terminal of the solar module, A first current sensor for outputting a charging current value to the microcomputer, a second inductor for preventing an inrush current at the time of discharging, a second current sensor for outputting a discharging current value measured at the time of discharging to a microcomputer, A load; A 24V DC direct load of the (-) terminal and a third switch controlled by the microcomputer, a second reverse diode for reverse current prevention and rectification, which is serially connected in series to the (-) terminal of the solar module; A battery charging overvoltage protection circuit, a 24V DC battery, and a second inductor connected in parallel between the first current sensor and the second inductor in parallel, A switch; A second voltage sensor connected in parallel between the battery charging overvoltage protection circuit and the 24V DC battery and between the second rectifier diode and the second switch in reverse direction and outputting the measured battery charging voltage value to the microcomputer; A 24V DC direct load of a (+) terminal connected in parallel between the second current sensor and a (+) terminal of a 12V DC direct load; And a 12V DC direct load connected in parallel between the third switch and the second switch through a fourth switch controlled by a microcomputer so that the microcomputer can turn on / Discharge control operation and the direct-current load damage prevention control operation by the control algorithm based on the charge / discharge control operation.

In the solar battery charge / discharge control device of the present invention, the first diode, the first inductor, the first switch, the first current sensor, the battery charging overvoltage protection circuit, the 24V DC battery, the second switch, and the second diode A DC-DC converter charging circuit is configured and includes a 24V DC battery, a battery charging overvoltage protection circuit, a second inductor, a second current sensor, and both a third switch or a fourth switch or a third and fourth switch, And a discharge circuit is constituted by a plurality of discharge cells.

In the solar battery charge / discharge control device of the present invention, the microcomputer is configured to charge the 24V DC battery when fully charged, and to prevent the battery from being damaged due to the overload of the battery, The microcomputer turns off the first switch and the second switch when the charging current value measured by the microcomputer is I > I _max , secures the minimum current that can be driven by the microcomputer during discharging, The control unit turns off the third switch and the fourth switch when the discharge current value measured by the second current sensor is I < I _low .

In the solar battery charge / discharge control device of the present invention, the microcomputer controls the discharge current measured by the second current sensor by the control algorithm so as to prevent the direct current load from being damaged by flowing the rated current to the 12V DC direct load and the 24V DC direct load And turns off the first switch and the second switch when the value is I > I _high .

Discharge control of the microcomputer is performed by a manual operation mode and an automatic operation mode. In the case of the manual operation mode, the charge / discharge control operation of the microcomputer in the manual mode The microcomputer turns on the first switch and the second switch to charge the 24V DC battery, and when the discharge switch (LOAD) is pressed, the microcomputer switches the third switch or the fourth switch or the third or fourth switch Discharging control operation in which the 24V DC battery is discharged to both the 12V DC direct load or the 24V DC direct load or both the 12V DC and the 24V DC direct load by turning on both of the switches, When the automatic mode provided in the control panel is selected, the microcomputer receiving the solar radiation value measured by the solar radiation sensor for measuring the solar radiation amount of the solar light, If the amount of saturation value is larger than the set value of the solar radiation amount, the first switch and the second switch are turned on to charge the 24V DC battery. If the amount of solar radiation is less than the preset value, the third switch or the fourth switch, 4 switches are turned on to perform charging / discharging control operations in which a 24V DC battery discharges to both a 12V DC direct load or a 24V DC direct load or both a 12V DC and a 24V DC direct load.

The solar battery charge / discharge control device of the present invention further includes a temperature sensor for measuring the internal temperature of the charge / discharge control device. If the internal temperature of the charge / discharge control device is higher than the temperature set in the microcomputer, 3, and 4 switches are all turned off to stop performing the charge control operation until the temperature becomes lower than the set temperature.

According to the technical construction of the present invention described above, it is possible to prevent the damage of the charge / discharge switch, the battery, and the DC load by preventing the inrush current without adding any additional work and cost, Discharge control device capable of driving a battery can be provided. In addition to the prevention of the complete discharge of the battery using one battery, the charge / discharge control device can be miniaturized while preventing overcharge of the battery and damage of the direct current load.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a conceptual diagram of charge / discharge and DC load damage prevention control operations of the present invention. FIG. 3 is a schematic view of a charge / FIG. 4 is a photograph of an embodiment of the control panel of FIG. 3, and FIG. 5 is a photograph of an embodiment of a solar radiation sensor installed in FIG. 3 for measuring solar radiation.

The solar battery charge / discharge control apparatus of the present invention comprises a solar module (11) for converting and outputting the solar radiation amount of solar light to DC power; A DC-DC converter for boosting or reducing the irregular output DC power of the solar module to a DC power of a predetermined magnitude; The DC-DC converter is controlled by an A / D converter 31, a control algorithm 32 and a PWM switching method for maintaining the load output power at a constant level to charge and store the boosted or reduced output DC power, And a microcomputer 30 for discharging the charged DC power to the DC load.

The solar battery charging / discharging control device of the present invention having such a structure is characterized in that the generated voltage value measured by the solar module between the (+) terminal and the (-) terminal of the solar module 11 is supplied to the microcomputer 30, And a first inductor L1 for preventing inrush current during charging and a first inductor L1 for preventing inrush current in charging are connected to the (+) terminal of the photovoltaic module in parallel, A first switch SW1 controlled by the microcomputer 30, a first current sensor 12 outputting a measured charge current value to the microcomputer 30 during charging, a second inductor A second current sensor 21 for outputting the discharge current value measured at the time of discharge to the microcomputer 30 and a 12V DC direct load 22 (Load 12V of FIG. 4) of the (+) terminal are sequentially A reverse second diode (D2) for preventing reverse current flow and rectifying current to the (-) terminal of the solar module (), and a third diode And a 24V DC direct load 23 (Load 24V in FIG. 4) of a position SW3 and a negative terminal are serially connected in series and a battery 24 is connected between the first current sensor 12 and the second inductor L2. The charging overvoltage protection circuit 13, the 24V DC battery 14 and the second switch SW2 controlled by the microcomputer 30 are sequentially connected in parallel while the reverse second diode D2 and the third switch The second switch SW2 is connected in parallel.

The first diode D1, the first inductor L1, the first switch SW1, the first current sensor 12, the battery charging overvoltage protection circuit 13, the 24V DC battery 14, the second switch And the second diode D2 constitute a DC-DC converter charging circuit.

The battery charge voltage measured between the battery charging overvoltage protection circuit 13 and the 24V DC battery 14 and between the second rectifier diode 16 and the second switch 15 is output to the microcomputer 30 And the second voltage sensor 18 are connected in parallel.

(+) Terminal of a 24V DC direct load is connected in parallel between the second current sensor 21 and the (+) terminal of the 12V DC direct load 22, and the third switch SW3 and the second switch (-) terminals of the 12V DC direct-current load 22 are connected in parallel through a fourth switch SW4 controlled by the microcomputer 30 between the first switch SW1 and the second switch SW2.

The 24V DC battery 14, the battery charging overvoltage protection circuit 13, the second inductor L2, the second current sensor 21 and the third switch SW3 or the fourth switch SW4 or the third, Both the four switches SW3 and SW4, and the second switch SW2 constitute a discharge circuit.

The first, second, third, and fourth switches are MOSFET semiconductor switching elements. The 12V DC load 22 is a guide sign such as a low power DC motor and an emergency lamp, for example. For example, DC lamps such as mid-current DC motors and LEDs.

The microcomputer 30 not only calculates the charging current value of the first current sensor, the discharge voltage value of the second current sensor, the photovoltaic module generation voltage value of the first voltage sensor, and the battery charging voltage value of the first voltage sensor, The solar radiation amount measured by the irradiation amount sensor 40 as shown in Fig.

3, a temperature sensor 50 for measuring the internal temperature of the charge / discharge control device is provided in the charge / discharge control device of the present invention. When the microcomputer 30 receives the measured value of the temperature sensor, When the temperature is higher than the temperature set in the microcomputer 30, the microcomputer 30 turns off all of the first, second, third and fourth switches by the control algorithm 32 and stops performing the charge control operation until the temperature becomes lower than the set temperature Thereby preventing the charge / discharge control device from being damaged due to the temperature rise.

The measured values of the first and second current sensors, the first and second voltage sensors, the irradiation dose sensor, and the temperature sensor are buffered by the buffer (buffer of FIG. 1) and input to the microcomputer. The switch is controlled by a drive circuit (SW1, SW2, SW3, SW4 drive circuit in Fig. 1) controlled by the microcomputer.

The first diode D1 is connected to the positive terminal of the solar module 11 in the positive direction and the second diode D2 is connected to the negative terminal of the solar module 11 in the reverse direction This is because when the solar module 11 is reversely connected to the (+) terminal and the (-) terminal of the solar module connection part (Solar) of FIG. 4, which is the control panel of the charge / discharge control device of the present invention, DC converter charging circuit in order to prevent current from flowing.

The first inductor L1 allows an excessive inrush current input to the first switch and the battery to be smoothly inputted until the initial steady current is reached when the first and second switches are turned on in the DC-DC converter charging circuit It performs a function to prevent an excessive inrush current. Accordingly, the first inductor L1 can prevent the first switch and the 24V DC battery from being damaged, and can be restored by using the fuse, thereby reducing the replacement work and replacement cost of the new replacement.

The second inductor L2 allows the excessive inrush current to be inputted to the DC load side at the time of the ON and OFF of the third switch and / or the fourth switch in the discharging circuit to be smoothly input until the initial steady current, It performs a function to prevent inrush current. Accordingly, the second inductor L2 as a novel technology structure not realized in the prior art can prevent the damage of the DC load.

The charging / discharging circuit of the charging / discharging control device of the present invention having the above structure controls the charging / discharging control operation and the DC load damage prevention control operation by the microcomputer 30 on / off control of the first, second, (MPPT) algorithm.

The charging / discharging control operation of the microcomputer is performed manually or automatically by selecting the manual operation mode or the automatic operation mode of the control panel as shown in FIGS.

In the case of the manual operation mode, the automatic / manual mode selection switch (Auto / Menu) provided in the control panel of FIG. 4 of the charge and discharge control apparatus of FIG. 3 is pressed once to select the manual mode, When the upper charging light is turned on, the microcomputer 30 turns on the first switch SW1 and the second switch SW2 to charge the 24V DC battery 14. When the overcharge is detected, the automatic / manual mode selection switch When the discharge switch LOAD is turned on, the discharge lamp Discharge is turned on and the microcomputer 30 turns on the third switch SW3 and / or the fourth switch SW4 are turned on to perform the charging and discharging control operation in which the 24V DC battery 14 is discharged to both the 12V DC direct load 22 or the 24V DC direct load 23 or both the 12V DC and the 24V DC direct load.

In the case of the automatic operation mode, when the automatic mode (Auto) is selected by pressing the auto / manual mode selection switch (Auto / Menu) provided on the control panel of FIG. 4 of the charge / discharge control device of FIG. 3 twice, When the solar radiation amount measured by the control algorithm 32 is greater than the set solar radiation amount, the microcomputer 30 receives the solar radiation amount measured by the solar radiation sensor 40 of FIG. The third switch SW3 and / or the fourth switch SW4 are turned on to determine that the 24V DC is in the nighttime, and the second switch SW2 is turned on to charge the 24V DC battery 14, Discharging control operation in which the battery 14 is discharged to both the 12V DC direct load 22 or the 24V DC direct load 23 or both the 12V DC and the 24V DC direct load.

As described above, according to the present invention, the microcomputer 30 turns on the third switch SW3 and / or the fourth switch SW4 to change the rated voltage according to the electrical characteristics of the DC load (12 V DC or 24 V DC) And can be applied to various DC loads by providing them to the load.

The microcomputer 30 performs the control operation as shown in FIG. 2 by the control algorithm 32 during charging / discharging by the automatic operation mode.

The microcomputer 30 controls the charge current value measured by the first current sensor 12 as the battery overcharge condition by the control algorithm 32 so as to prevent the battery damage due to the overload while fully charging the 24V DC battery 14 during charging, (current) than I> I _max if (control algorithm 32 of the MPPT algorithm the maximum power operating point (MPPT operating) by) one (the I battery damage threshold current set in the charging current value I is a microcomputer (30) _max The first switch SW1 and the second switch SW2 are turned off.

Then, the microcomputer controls the current using the PWM switching method in the non-MPPT operating range of FIG. 2 by the control algorithm 32 as follows.

The microcomputer 30 maintains a minimum current that can be driven by the microcomputer during discharging so as to prevent the microcomputer from being driven due to the full discharge of the 24V DC battery 14 by the control algorithm 32, When the discharge current value measured by the current sensor 21 is I < I _low (when the discharge current value I is smaller than the microcomputer-driven threshold current I _low set in the microcomputer 30) And the fourth switch SW4 are turned off.

Also, the microcomputer can measure the full charge and the full discharge by the second voltage sensor 16 in addition to the battery overcharge condition and the over discharge condition described above.

Then, the microcomputer 30 controls the second current sensor (not shown), which is the DC load damage condition, by the control algorithm 32 so as to prevent the DC load from being damaged by flowing the rated current to the 12V DC load 22 and the 24V DC load 23 When the discharge current value measured by the first switch SW1 and the second switch 21 is I > I _high (when the discharge current value I is larger than the load damage threshold current I _high set in the microcomputer 30) (SW2) is turned off.

By the control algorithm 32 of the microcomputer, it is possible to prevent the battery from being overcharged and the DC load from being damaged by using one 24V DC battery 14 in addition to the prevention of the complete discharge of the battery, .

1 is a block diagram of a control circuit of a charge / discharge control device of the present invention.

FIG. 2 is a conceptual diagram of charge / discharge and DC load damage prevention control operations of the present invention. FIG.

3 is a photograph of an embodiment of the charge / discharge control device of the present invention.

4 is a photograph of an embodiment of the control panel of Fig.

FIG. 5 is a photograph of an embodiment of the irradiation dose sensor installed in FIG. 3; FIG.

DESCRIPTION OF REFERENCE NUMERALS

11; Solar module 12: first current sensor

14: 24V DC battery 15: first voltage sensor

16: second voltage sensor 21: second current sensor

22: 12V DC load 23: 24V DC load

30: Microcomputer 32: Control algorithm

40: Solar radiation sensor 50: Temperature sensor

D1, D2: first and second diodes L1, L2: first and second inductors

SW1, SW2, SW3, SW4: 1st, 2nd, 3rd, 4th switch

Claims (6)

A solar module for converting and outputting a solar radiation amount of solar light into direct current power; A DC-DC converter for boosting or reducing the irregular output DC power of the solar module to a DC power of a predetermined magnitude; This DC-DC converter is controlled by an A / D converter, a maximum power follow-up (MPPT) algorithm and a PWM switching method to keep the load output power constant, and the boosted or stepped output DC power is charged and stored in the battery. And a microcomputer for discharging the charged DC power from the battery and providing the DC load to the DC load, the charge / A first voltage sensor connected in parallel between the (+) terminal and the (-) terminal of the photovoltaic module and outputting the measured power generation voltage value to the microcomputer; A first inductor for preventing reverse current flow and rectification, a first inductor for preventing an inrush current during charging, a first switch controlled by a microcomputer, which is connected in series to the (+) terminal of the solar module, A first current sensor for outputting a charging current value to the microcomputer, a second inductor for preventing an inrush current at the time of discharging, a second current sensor for outputting a discharging current value measured at the time of discharging to a microcomputer, A load; A 24V DC direct load of the (-) terminal and a third switch controlled by the microcomputer, a second reverse diode for reverse current prevention and rectification, which is serially connected in series to the (-) terminal of the solar module; A battery charging overvoltage protection circuit, a 24V DC battery, and a second inductor connected in parallel between the first current sensor and the second inductor in parallel, A switch; A second voltage sensor connected in parallel between the battery charging overvoltage protection circuit and the 24V DC battery and between the second rectifier diode and the second switch in reverse direction and outputting the measured battery charging voltage value to the microcomputer; A 24V DC direct load of a (+) terminal connected in parallel between the second current sensor and a (+) terminal of a 12V DC direct load; And a 12V DC direct load of a (-) terminal connected in parallel through a fourth switch controlled by a microcomputer between the third switch and the second switch Wherein the microcomputer performs the charge / discharge control operation and the DC load damage prevention control operation by a control algorithm by on / off control of the first, second, third, and fourth switches. The method according to claim 1, A DC-DC converter charging circuit is constituted by a first diode, a first inductor, a first switch, a first current sensor, a battery charging overvoltage protection circuit, a 24V DC battery, a second switch, and a second diode, The discharge circuit is constituted by the 24V DC battery, the battery charging overvoltage protection circuit, the second inductor, the second current sensor, and both the third switch or the fourth switch or the third and fourth switches, and the second switch Charge / discharge control device for a solar battery. The method according to claim 1 or 2, The microcomputer calculates the charge current value measured by the first current sensor by the maximum power follow-up (MPPT) algorithm of the control algorithm so that the charge current value of the 24V DC battery is I> I _max The first switch and the second switch are turned off, The microcomputer sets the discharge current value measured by the second current sensor to I < I _low by the control algorithm so as to prevent the microcomputer from being driven due to the full discharge of the 24V DC battery by securing the minimum current that can be driven by the microcomputer during discharge. , The third switch and the fourth switch are turned off. The method according to claim 1 or 2, When the discharge current value measured by the second current sensor is I> I _high by the control algorithm to prevent the DC load from being damaged by flowing the rated current to the 12V DC direct load and the 24V DC direct load, And the second switch is turned off. The method according to claim 1 or 2, The charge / discharge control operation of the microcomputer is performed by the manual operation mode and the automatic operation mode, In the manual operation mode, the microcomputer turns on the first switch and the second switch to charge the 24V DC battery by selecting the manual mode provided on the control panel of the charge / discharge control device and press the charge switch (Charge) LOAD), the microcomputer turns on either the third switch or the fourth switch or the third or fourth switch so that the 24V DC battery discharges to both a 12V DC load or a 24V DC load or a 12V DC and a 24V DC load Discharge control operation, In the case of the automatic operation mode, when the automatic mode provided in the control panel of the charge / discharge control device is selected, the microcomputer having received the irradiation value measured by the irradiation amount sensor for measuring the irradiation amount of sunlight, If it is determined that it is a day, the first switch and the second switch are turned on to charge the 24V DC battery. If the value is less than the set value, it is determined to be the nighttime, and the third switch, the fourth switch, Discharge control operation in which the 24V DC battery is discharged to both the 12V DC direct load or the 24V DC direct load or both the 12V DC and the 24V DC direct load by turning on the other. The method according to claim 1 or 2, When the internal temperature of the charge / discharge control device is higher than the temperature set in the microcomputer, the microcomputer turns off all of the first, second, third and fourth switches by a control algorithm to set And stops the execution of the charge control operation until the temperature becomes lower than the predetermined temperature.

Images