KR20130082240A - Control device for charging and discharging of super capacitor and rechargeable battery - Google Patents

Abstract

PURPOSE: A charging and discharging control device can extend the lifetime of a rechargeable battery by discharging a super capacitor having a low energy density and then by discharging a rechargeable battery having a high energy density. CONSTITUTION: A solar cell (12) outputs electric energy (Solar_V) by converting solar energy. First and second boost convertors (18, 19) output a constant voltage by raising/converting electronic energy outputted from the solar cell. The first and second boost convertors charge a super capacitor (14) and a rechargeable battery (16), each of which are connected to an output node. A capacitor discharge unit (22) supplies capacitive voltage (CAP_V) stored in the super capacitor to a load. A battery discharging unit (24) supplies charging voltage (Bat_V) charged in the rechargeable battery to the load. [Reference numerals] (12) Solar cell; (14) Super capacitor; (16) Rechargeable battery; (18) First boost converter; (19) Second boost converter; (22) Capacitor discharge unit; (24) Battery discharging unit

Description

Control device for charging and discharging of super capacitor and Rechargeable battery}

The present invention relates to a device for controlling charging and discharging of a supercapacitor and a rechargeable battery. More particularly, the present invention relates to charging a rechargeable battery and a supercapacitor with a voltage output from a solar cell, and to blocking the voltage. The present invention relates to a supercapacitor and a charge / discharge control device for a rechargeable battery, which control to discharge the supercapacitor from the supercapacitor in the order of the rechargeable battery.

A solar cell converts the energy of solar light into electrical energy when the solar light is applied to a cell formed by the junction of a P-type semiconductor and an N-type semiconductor, and its structure is different from that of a chemical cell. . Such solar cells can obtain electricity at any time as long as they have bright light, and their use is spreading widely. Such solar cells have a different amount of electric power, that is, voltage level, depending on the intensity of light energy. Therefore, in order to stably drive an electronic device operated by a stable DC voltage, a rechargeable battery or a storage battery may be used. The same energy store must be used.

Because storage batteries are very large, small electronic devices, road traffic signs or parks that drive light emitting diode (LED) lamps, etc., are used for solar cells, such as lithium ion batteries with high storage energy density. It is used as an energy storage device. Such rechargeable batteries have been widely used as energy storage devices for solar cells because of their high energy density of 20 to 120 Wh / kg and the ability to repeatedly discharge and charge, but the charge and discharge characteristics are limited to 1000 cycles. Regular maintenance was required, and after a certain period of use, it was troublesome to replace the rechargeable battery.

In order to solve the shortcomings of the rechargeable battery as described above, a technique of using a capacitor as an energy storage device is disclosed in Patent Document 1 below. The "light emitting block" published in the patent document is charged to the capacitor (capacitor) to the voltage output from the solar cell during the day, and discharge the light charged to the capacitor at night to emit light to the light emitting surface It is configured to. The capacitor has the advantage of eliminating the problems appearing when using a rechargeable battery as a storage of solar energy due to the advantage that the charge and discharge is semi-permanent, but because the energy density is low to 1 ~ 10Wh / kg and often need to be charged often during the rainy season Likewise, when the weather is cloudy for a long time, there is a problem in that a sufficient voltage cannot be charged in the capacitor and thus, a light emitting device formed on the light emitting surface, for example, a lamp such as an LED lamp cannot be driven brightly.

US Patent No. 6,655,814 (Dec. 2, 2003 registered)

Accordingly, an object of the present invention is to use a solar energy storage device to charge the electrical energy output from the solar cell to the supercapacitor and the rechargeable battery, and configured to charge and discharge the electrical energy stored in the solar energy storage device in an optimal state for a long time. An object of the present invention is to provide a charge / discharge control device for a supercapacitor and a rechargeable battery.

Another object of the present invention is to charge the electric energy output from the solar cell in a solar energy storage device consisting of a supercapacitor and a rechargeable battery, and loads in order of the rechargeable battery to the supercapacitor when the electric energy is not output from the solar cell. The present invention provides a charge / discharge control device for a supercapacitor and a rechargeable battery that is operated to supply electrical energy.

The present invention for achieving the above object, the solar cell unit for converting and outputting solar energy into electrical energy; A supercapacitor and a rechargeable battery for charging the electrical energy between negative electrodes; A capacitor discharge unit for supplying a capacitive voltage stored in the supercapacitor to a load when the voltage level of the electrical energy is less than or equal to a preset level; When the voltage level of all the electrical energy and the capacitive voltage is less than a predetermined level is characterized in that the battery discharge unit for supplying the charge voltage charged in the rechargeable battery to the load.

The solar cell unit converts light energy into electrical energy and outputs it, a first boost converter that charges the supercapacitor by converting the electrical energy into a constant voltage of a first level, and the electrical energy. And a second boost converter configured to convert the voltage into a constant voltage of a second level to charge the rechargeable battery.

The capacitor discharge unit outputs a first discharge control signal for discharging the capacitive voltage in response to a voltage level of the electrical energy being below a predetermined level, and in response to an input of the first discharge control signal; And a third boost converter which converts the capacitive voltage into a constant voltage and provides the load to the load.

The first discharge controller is configured to provide a capacitive voltage sensing supplying the activated first discharge control signal to the third boost converter in response to the case where the level of the capacitive voltage is higher than or equal to a predetermined level, and the voltage level of the electrical energy is increased. And a first discharge circuit breaker for blocking the first discharge control signal provided to the third boost converter when a predetermined level or more is exceeded.

The battery discharge unit outputs a second discharge control signal for discharging the charging voltage in response to the voltage level of the electrical energy and the level of the capacitive voltage being below a predetermined level;

And a fourth boost converter configured to convert the charging voltage into a constant voltage and provide the load to the load in response to the input of the second discharge control signal.

The second discharge control unit may include a charge voltage detector configured to supply an activated second discharge control signal to the four boost converter in response to the case where the level of the charge voltage is greater than or equal to a predetermined level, and any one of the level of the electric energy and the capacitive voltage. And a charge voltage discharge circuit breaker for blocking the second discharge control signal supplied to the fourth boost converter when one is above a predetermined level.

A reverse current prevention diode may be connected to each of the output nodes of the first and second boost converters to prevent reverse current inflow from the supercapacitor and the rechargeable battery to the first and second boost converters.

Charge and discharge control device according to an embodiment of the present invention charges the electric energy to the supercapacitor and the rechargeable battery by a voltage that converts the solar energy into electrical energy in the solar cell during the day, and is charged in the supercapacitor at night The electrical energy is first discharged to the load side, and when the level of the capacitive voltage charged in the supercapacitor is discharged below a predetermined voltage, the charging voltage charged in the rechargeable battery, which is the secondary battery, is discharged to continuously apply a constant voltage to the load. By supplying, it is possible to operate the load for a long time without input of commercial AC power.

1 is a block diagram of a charge / discharge control apparatus of a supercapacitor and a rechargeable battery according to an exemplary embodiment of the present invention.
FIG. 2 is a view illustrating a specific embodiment of the capacitor discharge unit shown in FIG. 1. FIG.
3 is a diagram illustrating a specific embodiment of the battery discharge unit shown in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. It should be understood, however, that the invention can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It should be noted that the embodiments of the present invention described below are intended to sufficiently convey the spirit of the present invention to those skilled in the art.

Referring to FIG. 1, the charge / discharge control apparatus 10 of a supercapacitor and a rechargeable battery according to an exemplary embodiment of the present invention converts solar energy into electrical energy and outputs a DC voltage corresponding to solar energy 12. Equipped with. The electrical energy Solar_V output from the solar cell 12 is supplied to the first and second boost converters 18. 19, the capacitor discharge unit 22, and the battery discharge unit 24. In the solar cell 12 as described above, since the output voltage level changes in response to the amount of sunlight falling down during the day, the first and second boost converters 18 and 19 as described above may be used.

Each of the first and second boost converters 18 and 19 has a DC-DC converter therein. In the DC-DC converter, when a DC voltage of a predetermined level or more is input, it is preferable to use a device for boosting the voltage to a constant voltage level to perform a constant voltage. An example of such a DC-DC converter can be implemented using a TPS6101X series boost converter manufactured by semiconductor maker "Texas Instruments Incorporated". The output of each of the first and second boost converters 18 and 19 may be appropriately set according to the charge level of the supercapacitor 14 and the rechargeable battery 16. In addition, when the capacity of the supercapacitor 14 and the rechargeable battery 16 is the same, only one of the first and second boost converters 18 and 19 may be used.

The first and second boost converters 18 and 19 output a constant voltage by boosting / converting electrical energy output from the solar cell 12 during a day in which solar energy is present. 12) and the first and second booster converters 18 and 19 are defined as solar cell units, and the constant voltage output from the first and second booster converters 18 and 19 should also be defined as electrical energy.

The electrical energy output from the output node of the first boost converter 18, that is, the constant voltage is supplied to the supercapacitor 14 and the capacitor discharge unit 22 through the one-way diode 20, and the second boost converter 19. The electrical energy, that is, the constant voltage that is output from the output node of the power supply is supplied to the rechargeable battery 16 and the battery discharge part 24 through the one-way diode 21. At this time, the two diodes 20 and 21 are for blocking the reverse voltage flowing back from the supercapacitor 14 and the rechargeable battery 16.

When the sun light falls on the surface of the solar cell 12 during the day, the solar cell 12 converts solar energy into electrical energy (Solar_V) as already known, and thus, the first and second boost converters 18. The first and second boost converters 18 and 19 boost the electrical energy (Solar_V) and convert them into constant constant voltages, respectively, to supply the supercapacitor 14 and the rechargeable battery 16 respectively connected to the output node. To charge. In the present invention, the voltage charged or discharged from the supercapacitor 14 is defined as the capacitive voltage CAP_V, and the voltage charged or discharged from the rechargeable battery 16 is defined as the charging voltage Bat_V.

On the other hand, the capacitor discharge unit 22 and the battery discharge unit 24 for inputting the electric energy (Solar_V) output from the solar cell 12 is disabled when the electric energy (Solar_V) is above a certain voltage level (Disable) Thus, the discharge operation is not performed. That is, during the day, only the operation of charging the supercapacitor 14 and the rechargeable battery 16 by the electric energy (Solar_V) output from the solar cell 12 is performed.

If the energy of light is not supplied to the solar cell 12 after sunset or because it is very dark, the voltage level of the electric energy (Solar_V) output from the solar cell 12 becomes 0 volts, thereby increasing the first and second boosts. No voltage is output from the converters 18 and 19.

On the other hand, the capacitor discharge unit 22 is enabled by the voltage level of the electric energy Solar_V being lowered and the capacitive voltage CAP_V charged in the supercapacitor 14 to the operating voltage VDD of the load. And the battery discharge part 24 is enabled when the voltage levels of the electric energy Solar_V and the capacitive voltage CAP_V are lower than a predetermined level, and are charged in the rechargeable battery 16. The charging voltage Bat_V is discharged to the operating voltage VDD on the load side. At this time, when the level of the capacitive voltage CAP_V is such that the load can be operated, the battery discharge part 24 maintains the disabled state to start discharging after the voltage discharged in the supercapacitor 14 is discharged. It can be seen that.

The configuration and operation of the capacitor discharge unit 22 and the battery discharge unit 24 shown in FIG. 1 will be described below with reference to FIGS. 2 and 3, respectively.

Referring to FIG. 2, the capacitor discharge unit 22 is largely composed of a first discharge control unit 26 and a third boost converter 28. The capacitive voltage sensor 30 in the first discharge control unit 26 divides the capacitive voltage CAP_V discharged from the supercapacitor 14 by two resistors R13 and R14 connected in series to form a transistor ( Supply to the base of Q5). At this time, when the voltage divided by the two resistors R13 and R14 is high enough to turn on the transistor Q5, for example, 0.7 volts, the transistor Q5 is 'turned on' and the transistor is turned on. Since Q6 is 'turned off', the first discharge control signal CAP-V-On in a logic 'high' state is enabled by the enable terminal EN of the DC-DC converter 29 in the third boost converter 28. Is supplied.

The resistors R15, R16 and R17 connected to the capacitive voltage CAP_V and the base and emitter of the transistor Q6, respectively, are used for current control. Accordingly, the capacitive voltage sensor 30 may apply the first discharge control signal CAP_V_On activated in response to the case where the level of the capacitive voltage CAP_V is higher than or equal to a predetermined level. It can be seen that it is supplied to the enable terminal EN of the DC converter 29.

The first discharge breaker 31 in the first discharge control unit 26 is configured to generate a predetermined voltage when the voltage level of the electric energy Solar_V is higher than or equal to a predetermined level, that is, when a constant voltage is output from the solar cell 12 during the day. The first discharge control signal CAP_V_On is bypassed through the collector and the emitter path of the transistor Q7 to transition the first discharge control signal CAP_V to logic "low". Therefore, when the capacitive voltage CAP_V charged in the supercapacitor 14 is sufficiently high and the electric energy Solar_V is not output from the solar cell 12 at night by the above technical configuration, the third boost converter 28 is used. The DC-DC converter 29 in the parentheses is enabled.

When the first discharge control signal CAP_V_On remains in a logic " high " state, the coil L2, capacitors C5 to C7, resistors R21 and R22 and a DC-DC converter 29 are configured. The third boost converter 28 converts the capacitive voltage CAP_V discharged from the supercapacitor 14 into a constant voltage and outputs the constant voltage to the operating voltage VDD of the load. In this case, the DC-DC converter 29 and related components constituting the third booster converter 28 may be configured by using the boost converter of the TPS6101X series of "Texas Instruments Incorporated".

When the capacitive voltage CAP_V falls below a predetermined level due to continuous discharge of the supercapacitor 14, the transistor Q5 in the capacitive voltage sensor 30 is 'turned off' and the transistor Q6 is 'turned on'. Then, the first discharge control signal CAP_V is shifted to a logic " low " to disable the third booster converter 28 to stop the operation.

At this time, the battery discharge unit 24 configured as shown in FIG. 3 discharges the voltage charged in the rechargeable battery 16 just before the operation of the third boost converter 28 of FIG. 2 is supplied to the load. same.

Referring to FIG. 3, the battery discharge control unit 24 is largely composed of a second discharge control unit 32 and a fourth boost converter 34. The first discharge controller 26 includes a charge voltage detector 36, a second discharge breaker 38, and a second capacitor substantially the same as those of the capacitive voltage detector 30 and the first discharge breaker 31 of FIG. 2. The three discharge interrupting portions 40 are provided.

The charging voltage sensor 36 composed of the transistors Q1 and Q2 and the resistors R1 to R5 has a second discharge control signal activated with a logic 'high' in response to the case where the voltage level of the charging voltage Bat_V is higher than or equal to a predetermined level. (Bat_V_On) is supplied to the enable terminal EN of the DC-DC converter 35 in the four boost converter 34. Of course, since the voltage divided by the resistors R1 and R2 cannot turn on the transistor Q1, the level of the charging voltage Bat_V is discharged or the capacitive voltage CAP_V is sufficiently high, so that the resistor R6 The second discharge when the transistor Q3 is turned on by the voltage divided by R7 or the output of the resistors R6 and R7 divides the voltage of the electric energy Solar_V. The control signal Bat_V_On is output as "logical".

The second discharge controller 36 configured as described above is configured to generate the voltage when the voltage level of the electric energy Solar_V7 and the capacitive voltage CAP_V is less than or equal to a predetermined level when the voltage level of the charging voltage Bat_V is higher than or equal to a predetermined level. The DC-DC converter 35 in the 4-boost converter 28 is enabled. When the DC-to-DC converter 35 in the fourth boost converter 28 is enabled, the first circuit includes a coil L1, capacitors C2 to C4, resistors R10 and R11, and a DC-DC converter 35. The four boost converter 34 converts the charging voltage Bat-_V output from the rechargeable battery 16 into a constant voltage and outputs it to the operating voltage VDD of the load. In this case, the fourth boost converter 34 is also configured in the same manner as the third boost converter 28 described above.

As described above, the voltage divided by the two resistors R1 and R2 connected in series between both ends of the charging voltage Bat_V charged in the rechargeable battery 16 cannot cause the transistor Q1 to be 'on'. When the voltage level of the voltage Bat_V drops, the second discharge control signal Bat_V_On is deactivated to a logic "low" to prevent the full discharge of the rechargeable battery 14, thereby stopping the operation of the fourth boost converter 34.

The charge / discharge control device 10 of the supercapacitor and the rechargeable battery of the present invention having the configuration as described above charges the voltage to the supercapacitor 14 and the rechargeable battery 16 during the day when the solar energy falls, and the super at night The capacitor 14 is discharged in the order from the capacitive voltage CAP_V charged in the capacitor 14 to the charging voltage Bat_V charged in the rechargeable battery 16. Therefore, when the capacitive voltage CAP_V charged to the supercapacitor 14 can sufficiently drive a load such as an LED lamp at night, the rechargeable battery 16 may not be charged or discharged. ) Can extend the life of the.

10 Charge / discharge control device, 22 Capacitor discharge unit, 24 Battery discharge unit, 26 First discharge control unit, 28 Third boost converter, 29, 35 DC-DC converter, 30 Capacitive voltage sensor, 31 First discharge breaker, 32 2 discharge control unit, 34 fourth boost converter, 36 charge voltage sensor, 38 second discharge breaker, 40 third discharge breaker

Claims (6)

A charge / discharge control device for a supercapacitor and a rechargeable battery, the apparatus comprising: a solar cell unit converting solar energy into electrical energy and outputting the electrical energy; A supercapacitor and a rechargeable battery for charging the electrical energy between negative electrodes; A capacitor discharge unit for supplying a capacitive voltage stored in the supercapacitor to a load when the voltage level of the electrical energy is less than or equal to a preset level; Charge and discharge control of the supercapacitor and the rechargeable battery, characterized in that the battery discharge unit for supplying the charge voltage charged in the rechargeable battery to the load when all voltage levels of the electrical energy and the capacitive voltage is less than a predetermined level. Device. The solar cell unit of claim 1, wherein the solar cell unit converts light energy into electrical energy and outputs the electrical energy, a first boost converter that converts the electrical energy into a constant voltage of a first level, and charges the supercapacitor; And a second boost converter configured to convert energy into a constant voltage of a second level to charge the rechargeable battery. 3. The first discharge controller of claim 2, wherein the capacitor discharge unit outputs a first discharge control signal for discharging the capacitive voltage in response to a voltage level of the electrical energy being lower than or equal to a predetermined level. And a third boost converter configured to convert the capacitive voltage into a constant voltage and provide the load to the load in response to an input of a signal. The second discharge control signal according to any one of claims 1 to 3, wherein the battery discharge unit discharges the charging voltage in response to the voltage level of the electrical energy and the level of the capacitive voltage being lower than or equal to a predetermined level. And a fourth boost converter configured to output a second discharge controller and a fourth boost converter to convert the charging voltage into a constant voltage and provide the load to the load in response to an input of the second discharge control signal. And a charge / discharge control device of a rechargeable battery. 5. The capacitive voltage sensing device of claim 4, wherein the first discharge control unit supplies the first discharge control signal activated to the third boost converter in response to the case where the level of the capacitive voltage is greater than or equal to a predetermined level. And a first discharge circuit breaker for blocking the first discharge control signal provided to the third boost converter when the voltage level of the electric energy is higher than or equal to a predetermined level. 5. The charging device of claim 4, wherein the second discharge control unit supplies a second discharge control signal activated to the four boost converters in response to the case where the level of the charging voltage is higher than or equal to a predetermined level. A charge / discharge control device for a supercapacitor and a rechargeable battery, characterized in that it comprises a charge voltage discharge circuit breaker that cuts off the second discharge control signal supplied to the fourth boost converter when any one of the levels of the gender voltage is above a predetermined level.

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