CN106816948B - A 12V battery photovoltaic mains mutual supplement and discharge maintenance device - Google Patents

Abstract

A12V storage battery photovoltaic mains supply complementary charge-discharge maintenance device comprises a photovoltaic mains supply complementary combination logic control module and a storage battery charge-discharge comparison control module, wherein the values of R1, R2, R3 and R4 and first and second reference voltages are set, when the terminal voltage of the storage battery reaches an overcharge-off voltage, a first voltage hysteresis comparator is used for disconnecting the charge of the storage battery through a third relay, the overcharge-off state is maintained until the terminal voltage of the storage battery reaches a charge-off recovery voltage, the charge of the storage battery is recovered when the terminal voltage of the storage battery reaches the charge-off recovery voltage, and when the terminal voltage of the storage battery reaches the overdischarge-off voltage, a second voltage hysteresis comparator is used for disconnecting the discharge of a load through a fourth relay, and the overdischarge-off state is maintained until the terminal voltage of the storage battery reaches the discharge-off recovery voltage. The invention can automatically detect the state of the storage battery, and perform automatic charge and discharge and turn-off control and turn-off recovery control.

Description

A 12V battery photovoltaic mains mutual supplement and discharge maintenance device

Technical field

The invention relates to a photovoltaic mains power mutual supplement and discharge maintenance device for a battery with a nominal voltage of 12V.

Background technique

In daily life, because batteries have the advantages of portability and reusability, many commonly used electronic devices or instruments are powered by 12V batteries. Most of these electronic devices are mainly portable. With the development of renewable new energy, It will become a trend to use photovoltaic and mains electricity complementary methods to charge batteries. In addition, the correct charging and discharging method not only saves costs, but also effectively extends the service life of the battery. The ideal terminal voltage range of a battery with a nominal voltage of 12V is 12V ~ 13.5V. Whether the battery is in an overdischarge or overcharge state will affect the battery life. Regarding the service life of the battery, when using a battery with a nominal voltage of 12V, you should try to avoid the terminal voltage of the battery being less than 12V or higher than 14.5V for a long time.

For batteries that have been in an over-discharged or overcharged state for a long time, the internal conductive ions cannot be effectively stimulated, and the battery's service life will be greatly affected by improper use. Users often do not know the remaining battery power when using the battery, and the battery does not perform maintenance. Timely and effective charging and discharging may lead to insufficient power or unstable use of the equipment during operation.

Contents of the invention

Aiming at the above-mentioned deficiencies in the prior art, the present invention provides a 12V battery photovoltaic mains power mutual supplement and discharge maintenance device, which can detect the state of the battery with a nominal voltage of 12V, and perform automatic charge and discharge and shutdown control, so that The voltage of the battery has been stable within a relatively normal range for a long time.

In order to solve the above technical problems, the present invention adopts the following technical solutions:

A 12V battery photovoltaic mains complementary supplement and discharge maintenance device, including a power module, a photovoltaic mains complementary combination logic control module, and a battery charge and discharge comparison control module. The nominal voltage of the battery is 12V;

The photovoltaic mains complementary combination logic control module includes a non-self-locking button. The non-self-locking button realizes binary addition counting of the number of button presses through a double D trigger counting module. The output end of the non-self-locking button also triggers a data through a delay circuit. Latch circuit output, the output terminals of the two D flip-flops of the double D trigger counting module are connected to the data input terminal of the data latch circuit, and a data output terminal of the data latch circuit is connected to the first relay through an optocoupler isolation circuit , the contact of the first relay can connect the output port OUT1 to the photovoltaic interface P1 for charging, the other data output end of the data latch circuit is connected to the second relay through the optocoupler isolation circuit, and the contact of the second relay can connect the output port OUT1 Mains interface P2 is charged. The output levels of the two D flip-flops of the double D trigger counting module can enable the output port OUT1 to be connected to one of the photovoltaic interface and the mains interface for charging alone, and to be connected to the photovoltaic interface and the mains interface for charging at the same time. , and in shutdown mode, neither the photovoltaic interface nor the mains interface charges the output port;

A first diode to prevent current reverse charging is connected between the photovoltaic interface P1 and the output port, and a second diode to prevent current reverse charging is connected between the mains interface P2 and the output port. When the photovoltaic interface When P1 and mains interface P2 charge the output port at the same time, the first diode can prevent the current from flowing back to the photovoltaic interface when mains charging is dominant, and the second diode can prevent the current from flowing back to the photovoltaic interface when photovoltaic charging is dominant. to the mains power interface to prevent damage to the photovoltaic power supply or mains power supply;

The battery charge and discharge comparison control module includes a first voltage hysteresis comparator and a second voltage hysteresis comparator, which are inverting voltage hysteresis comparators. The non-inverting input end of the first voltage hysteresis comparator is connected to the first voltage hysteresis comparator through a first resistor R1. The positive terminal of the reference voltage V _R1 has a first feedback resistor R2 connected between its non-inverting input terminal and the output terminal, and its reverse input terminal is connected to the positive terminal of the battery. The non-inverting input terminal of the second voltage hysteresis comparator passes through the third Three resistors R3 are connected to the positive terminal of the second reference voltage V _R2 , a second feedback resistor R4 is connected between its positive input terminal and the output terminal, and its reverse input terminal is connected to the positive terminal of the battery; the first voltage hysteresis comparator The output end is connected to the electromagnetic coil of the third relay through an NPN transistor. The charging indicator light is connected in parallel to both ends of the electromagnetic coil of the third relay. The normally closed contact of the third relay is connected to the overcharge shutdown indicator light and then connected in parallel to both ends of the output port OUT1. , its normally open contact is connected to the output port OUT1 on the battery charging circuit; the output end of the second voltage hysteresis comparator is connected to the electromagnetic coil of the fourth relay through an NPN transistor, and the over-discharge shutdown indicator light is connected in parallel to the fourth relay At both ends of the electromagnetic coil, the normally closed contact of the fourth relay is connected to the discharge circuit of the battery to the load, and the discharge indicator light is connected to the normally closed contact of the fourth relay and then connected in parallel to both ends of the battery;

The upper threshold voltage of the first voltage hysteresis comparator lower threshold voltage Where V _R1 is the above-mentioned first reference voltage, V _Z is the voltage stabilization value of the output Zener diode, let the upper threshold voltage V _p1 = overcharge shutdown voltage, and the lower threshold voltage V _p2 = charge shutdown recovery voltage, then it can Calculate the ratio of the first resistor R1 and the first feedback resistor R2 and the required value of the first reference voltage V _R1 ;

In the same way, the upper threshold voltage of the second voltage hysteresis comparator Lower threshold voltage/> Where V _R2 is the above-mentioned second reference voltage, V _Z is the voltage stabilization value of the output Zener diode, let the upper threshold voltage V _p1 = discharge shutdown recovery voltage, and the lower threshold voltage V _p2 = over-discharge shutdown voltage, then it can Calculate the ratio of the third resistor R3 and the second feedback resistor R4 and the required value of the second reference voltage V _R2 ;

When the terminal voltage of the battery rises to the overcharge shutdown voltage, the first voltage hysteresis comparator flips and outputs a low level, which cuts off charging of the battery through the NPN transistor and the third relay. At this time, the overcharge shutdown indicator light Lights up, and this overcharge shutdown state is maintained until the terminal voltage of the battery drops to the charge shutdown recovery voltage. When the charge shutdown recovery voltage is reached, the first voltage hysteresis comparator flips to high level, turning on the charging of the battery. At this time, the charging indicator light lights up; when the terminal voltage of the battery drops to the over-discharge shutdown voltage, the second voltage hysteresis comparator flips and outputs a high level, which disconnects the battery from discharging the load through the NPN transistor and the fourth relay. , at this time the over-discharge shutdown indicator light lights up. This over-discharge shutdown state is maintained until the terminal voltage of the battery reaches the discharge shutdown recovery voltage. When the discharge shutdown recovery voltage is reached, the first voltage hysteresis comparator flips to low level. , turn on the discharge of the battery, and the discharge indicator light will light up at this time.

Further, the first reference voltage V _R1 is composed of a first adjustable DC power supply, and the second reference voltage V _R2 is composed of a second adjustable DC power supply; the battery charge and discharge comparison control module is connected between the output port OUT1 and the battery. The diode D0 that prevents current reverse charging prevents the battery from discharging to the output port OUT1.

Further, the double D trigger counting module includes a cascaded first D flip-flop and a second D flip-flop. The clock end of the first D flip-flop is connected to the output end of the key anti-shake circuit. The first D flip-flop The D terminal of the second D flip-flop is connected to its reverse output terminal, the D terminal of the second D flip-flop is connected to its reverse output terminal, and the reverse output terminal of the first flip-flop is connected to the D terminal of the second D flip-flop, thus forming an asynchronous clock. Binary addition counting module, in which the second flip-flop is a high-bit output and the first flip-flop is a low-bit output;

The reverse output end of the first D flip-flop and the reverse output end of the second D flip-flop of the double D trigger counting module are connected to the data latch circuit, and a data output end IN0_out of the data latch circuit passes through an optocoupler. The isolation circuit and the PNP transistor Q1 are connected to the first relay. When the data output terminal IN0_out of the data latch circuit outputs a low level, the PNP transistor Q1 is turned on through the optocoupler isolation circuit, and the first relay is powered on. The normal state of the first relay The open contact is closed, allowing the output port OUT1 to connect to the photovoltaic interface P1 for charging;

The other data output terminal IN1_out of the data latch circuit is connected to the second relay through the optocoupler isolation circuit and the PNP transistor Q2. When the data output terminal IN1_out of the data latch circuit outputs a low level, the PNP transistor Q2 is connected through the optocoupler isolation circuit. is turned on, the second relay is powered on, and the normally open contact of the second relay is closed, allowing the output port OUT1 to connect to the mains interface P2 for charging;

When the data output terminal IN0_out and the data output terminal IN1_out of the data latch circuit U7 both output low level, it can be seen that it can drive the first relay and the second relay to power on at the same time, so that the photovoltaic interface P1 and the mains interface P2 are output at the same time. Port OUT1 supplies power;

When the data output terminal IN0_out and the data output terminal IN1_out of the data latch circuit U7 both output high level, this is the shutdown mode, and neither the photovoltaic interface nor the mains interface supplies power to the output port OUT1.

Further, the forward output terminals of the first D flip-flop and the second D flip-flop of the double D flip-flop are connected to the decoder, the first D flip-flop is connected to the low input terminal of the decoder, and the second D flip-flop is connected to the decoder. Connect the high-bit input terminal of the decoder. The decoder converts the input binary code into decimal and displays it through the digital tube. This can display the number of key presses of the non-self-locking key.

Preferably, the non-self-locking key is a double-pole double-throw switch S1, one blade of the double-pole double-throw switch S1 is connected to the input end of the key anti-shake circuit, and the other blade of the double-pole double-throw switch S1 is connected to the delay At the triggering end of the circuit, the two blades of the double-pole double-throw switch are linked, and the non-opening end of the double-pole double-throw switch S1 is grounded;

The key anti-shake circuit is an RS trigger anti-shake circuit. The RS trigger anti-shake circuit is composed of two NAND gates. After the double-pole double-throw switch S1 is pressed and released, the RS trigger anti-shake circuit The output end of the circuit triggers the double D trigger counting module to start working by rising edge level. The first D flip-flop and the second D flip-flop of the double D trigger counting module are both rising edge level triggered;

The delay circuit uses a 555 delay trigger circuit, which is a low-level trigger that starts delaying until the high level after the non-self-locking button is released to charge the charging capacitor C13 to a certain voltage. The 555 delay trigger circuit The output terminal only outputs a low level to trigger the data latch circuit to output data. The delay time of the 555 delay trigger circuit can be realized by adjusting its charging capacitor C13 and adjustable resistor R7.

Further, the 12V battery photovoltaic mains mutual supplement and discharge maintenance device also includes a battery voltage acquisition and display module. The battery voltage acquisition and display module uses the A/D conversion chip ICL7107, which is connected to both ends of the battery through a voltage acquisition circuit. The voltage The sampling point of the sampling circuit is connected to the high input terminal of ICL7107. The output terminal of ICL7107 directly drives four LED digital tubes. By setting the decimal point, the display range is ±19.99, which can realize the terminal voltage of the battery with a nominal voltage of 12V. Display, ICL7107 and LED digital tube constitute a digital voltmeter.

Preferably, the overcharge shutdown voltage of the battery is 14.1-14.5V, the charging shutdown recovery voltage is 13.1-13.5V, the over-discharge shutdown voltage is 10.8-12V, and the discharge shutdown recovery voltage is 11.5-12V.

Preferably, the NPN transistor is an NPN type composite transistor, which is composed of an NPN transistor and a PNP transistor cascaded. When the input terminal is high level, the NPN type composite transistor is turned on, and when the input terminal is low level , NPN type composite transistor cut-off.

Preferably, the overcharge shutdown voltage of the battery is 14.5V, the charge shutdown recovery voltage is 13.5V, the overdischarge shutdown voltage is 11V, and the discharge shutdown recovery voltage is 12V.

Preferably, the delay circuit uses chip NE555, the data latch circuit uses chip 74HC573, the double D flip-flop uses chip 74LS74, and the decoder uses chip 74LS47.

The beneficial effects of the present invention are: (1) It can automatically detect the state of a battery with a nominal voltage of 12V, thereby performing automatic charge and discharge, overcharge shutdown control, overdischarge shutdown control, and charge shutdown recovery control; Discharge shutdown and recovery control keeps the battery voltage stable within a relatively normal range for a long time, which can improve the battery's working efficiency and service life; users do not need to manually control the battery's charge, discharge, shutdown and recovery based on the battery's terminal voltage, and the degree of automation is high ;

(2) The output levels of the two D flip-flops of the dual D trigger counting module enable the output port OUT1 to be connected to one of the photovoltaic interface and the mains interface for charging alone, and simultaneously connected to the photovoltaic interface and the mains interface for charging, and in shutdown mode. Neither the photovoltaic interface nor the mains interface charges the output port OUT1; it is in line with the development direction of renewable new energy and has the advantages of energy saving and environmental protection.

Description of drawings

Figure 1 is one of the circuit diagrams of the photovoltaic mains complementary combinational logic control module of the present invention.

Figure 2 is the second circuit diagram of the photovoltaic mains complementary combinational logic control module of the present invention.

Figure 3 is the third circuit diagram of the photovoltaic mains complementary combinational logic control module of the present invention.

Figure 4 is the fourth circuit diagram of the photovoltaic mains complementary combinational logic control module of the present invention.

Figure 5 is a circuit schematic diagram of a battery charge and discharge comparison control module according to an embodiment of the present invention.

Figure 6 is a circuit diagram of a non-inverting voltage hysteresis comparator.

Figure 7 is the transfer characteristic diagram of the non-directional voltage hysteresis comparator.

FIG. 8 is a transmission characteristic diagram of the first voltage hysteresis comparator according to the embodiment of the present invention.

FIG. 9 is a transmission characteristic diagram of the second voltage hysteresis comparator according to the embodiment of the present invention.

Figure 10 is a circuit diagram of a battery voltage acquisition and display module according to an embodiment of the present invention.

FIG. 11 is a circuit diagram of dual 15V power supplies of the power module according to the embodiment of the present invention.

Figure 12 is a circuit diagram of dual 5V power supplies of the power module according to the embodiment of the present invention.

Detailed ways

The present invention will be described in further detail below with reference to the accompanying drawings and examples. It should be understood that the embodiments described here are only used to specifically illustrate the implementation of the present invention and do not constitute a limitation of the present invention.

Refer to Figure 1-12: A 12V battery photovoltaic mains complementary supplement and discharge maintenance device, including a power module, a photovoltaic mains complementary combination logic control module, and a battery charge and discharge comparison control module. The nominal voltage of the battery is 12V.

The photovoltaic mains complementary combination logic control module includes a non-self-locking button. In this embodiment, it is a double-pole double-throw switch S1 with two linked blades. One blade of the double-pole double-throw switch S1 passes through the RS button. The anti-shake circuit is connected to the double D trigger counting module, and the other knife of the double-pole double-throw switch is connected to the delay circuit U6. That is, the 4-terminal key_in of the double-pole double-throw switch in the figure is connected to the trigger terminal TRIG of the delay circuit U6. When When the double-pole double-throw switch S1 is pressed, key_in is low level and the delay circuit U6 is triggered;

The output terminal of the delay circuit U6 is connected to the enable terminal OE of the data latch circuit U7, and the reverse output terminals IN0 and IN1 of each D flip-flop of the double D trigger counting module are connected to the data input terminal of the data latch circuit U7. , after the delay circuit U6 delays for a certain period of time, the data output terminals IN0_out and IN1_out of the data latch circuit U7 are triggered to correspondingly output the data of their data input terminals IN0 and IN1; the data output terminal IN0_out of the data latch circuit U7 passes The optocoupler isolation circuit U9 and the PNP transistor Q1 are connected to the first relay K1. When the data output terminal IN0_out of the data latch circuit outputs a low level, the optocoupler isolation circuit U9 is turned on, the PNP transistor Q1 is turned on, and the first relay K1 electricity, the normally open contact of the first relay K1 is closed, so that the output port OUT1 is connected to the photovoltaic interface P1. In the figure, the positive end of the photovoltaic interface P1 is connected to the K+ of the output port OUT1 through D5, and the negative end of the photovoltaic interface P1 is connected through the closed The normally open contact is connected to K— of the output port OUT1;

The other data output terminal IN1_out of the data latch circuit U7 is connected to the second relay K2 through the optocoupler isolation circuit U12 and the PNP transistor Q2. When the data output terminal IN1_out of the data latch circuit outputs a low level, the optocoupler isolation circuit U12 conducts pass, the PNP transistor Q2 is turned on, the second relay K2 is powered on, and the normally open contact of the second relay K2 is closed, so that the output port OUT1 is connected to the mains interface P2, and the output port OUT1 is used to connect to the battery for charging;

When the two data output terminals IN0_out and IN1_out of the data latch circuit U7 both output low level, the first relay K1 and the second relay K2 are driven to power on at the same time, so that the photovoltaic interface P1 and the mains interface P2 both supply power to the output port OUT1. , that is, charging the battery at the same time; when the data output terminal IN0_out and the data output terminal IN1_out of the data latch circuit U7 both output high level, this is the shutdown mode, and neither the photovoltaic interface nor the mains interface supplies power to the output port OUT1;

The delay circuit U6 is used to wait for the completion of the non-self-locking key input and the final output of the double D trigger counting module to trigger the output of the data latch circuit;

A first diode D5 to prevent current reverse charging is connected between the photovoltaic interface P1 and the output port OUT1, and a second diode D7 to prevent current reverse charging is connected between the mains interface P2 and the output port OUT1. When the photovoltaic interface P1 and the mains interface P2 charge the output port OUT1 at the same time, the first diode D5 can prevent the current from flowing back to the photovoltaic interface when the mains charging is dominant, and the second diode D7 can prevent the photovoltaic charging from being dominant. When the current flows back to the mains interface, it prevents damage to the photovoltaic power supply or mains power supply;

The double D trigger counting module includes a cascaded first D flip-flop U11A and a second D flip-flop U11B. The clock end of the first D flip-flop is connected to the output end of the RS button anti-shake circuit. The D terminal of the second D flip-flop is connected to its reverse output terminal, the D terminal of the second D flip-flop is connected to its reverse output terminal, and the reverse output terminal of the first flip-flop is connected to the D terminal of the second D flip-flop, thus forming an asynchronous clock. Binary addition counting module, in which the second flip-flop is a high-bit output and the first flip-flop is a low-bit output;

The RS flip-flop anti-shake circuit is composed of two NAND gates U10A and U10B connected. When the non-self-locking button is pressed, its terminal 1 is low level. No matter whether the non-self-locking button is released from its terminal 1, as long as it does not contact its terminal 3, U10A always outputs low level, realizing the anti-shake function of the button. . After the non-self-locking button is pressed and released until it contacts its 3 terminals, U10A outputs a rising edge level, and the clock terminal CLK of the double D trigger counting module is a rising edge trigger. U10A outputs a rising edge level, and the double D trigger counting module The clock terminal CLK is triggered by the rising edge. In Figure 6, U11B is the high-order output and U11A is the low-order output. U11B and U11A realize the addition counting of 00, 01, 10, and 11 in sequence;

The specific process is that the logic function of the D flip-flop is: Q ⁿ⁺¹ =D, and the 74LS74 is a rising edge trigger. Therefore, in the figure, IN0=D0, IN1=D1, assuming that in the initial state, the outputs of the first and second D flip-flops are both 0, that is, A=0, B=0; then the first and second D flip-flops The reverse output terminals of the flip-flop are both 1, that is, IN0=1, IN1=1, so the D-end states of the first and second D flip-flops are D0=1, D1=1; when the output of the RS flip-flop anti-shake circuit terminal, that is, when the clock terminal CLK of the first D flip-flop changes from 0 to 1 for the first time, the state of U11A changes to A=1, IN0=0, D0=0; IN0=0 makes the clock terminal CLK of U11B Falling edge pulse, so the state of U11B does not change, that is, B=0, IN1=1, D1=1. At this time, the output of the double D trigger counting module (from high to low) is 01, that is, B=0, A=1;

When the clock terminal CLK of the first D flip-flop changes from 0 to 1 for the second time, the state of U11A changes to A=0, IN0=1, D0=1; IN0=1 makes the clock terminal CLK of U11B a rising edge. pulse, so the state change of U11B is B=1, IN1=0, D1=0. At this time, the output of the double D trigger counting module (from high to low) is 10, that is, B=1, A=0;

When the clock terminal CLK of the first D flip-flop changes from 0 to 1 for the third time, the state of U11A changes to A=1, IN0=0, D0=0; IN0=0 makes the clock terminal CLK of U11B fall on the falling edge. pulse, so the state of U11B does not change, that is, B=1, IN1=0, D1=0. At this time, the output of the double D trigger counting module (from high to low) is 11, that is, B=1, A=1;

When the clock terminal CLK of the first D flip-flop changes from 0 to 1 for the fourth time, the state of U11A changes to A=0, IN0=1, D0=1; IN0=1 makes the clock terminal CLK of U11B a rising edge. pulse, so the state of U11B changes to B=0, IN1=1, D1=1, and the output of the double D trigger counting module (from high to low) is 00, that is, B=0, A=0, returning the logical relationship to the initial status, thereby achieving the effect of additive counting.

According to the connection circuit between IN0 and IN1 of the double D trigger counting module and the first relay and the second relay through the data latch, it can be seen that in the initial state when the output of the double D trigger counting module is 00, when the button is pressed once, IN0 = 0, IN1＝1 connects the output port OUT1 to the photovoltaic interface for power supply. Press the button twice, IN0＝1, IN1＝0 enables the output port OUT1 to connect to the mains interface for power supply. Press the button three times, IN0＝0, IN1＝0. The output port OUT1 is connected to the photovoltaic interface and the mains interface for power supply at the same time. Press the button four times to return to the initial state. This is the shutdown mode. At this time, IN0=1 and IN1=1 make the photovoltaic interface and the mains interface not an output port. OUT1 is powered.

Table 1. Output status of photovoltaic mains complementary combinational logic control module

In this embodiment, the forward output ends of the first D flip-flop U11A and the second D flip-flop U11B of the double D flip-flop are connected to the decoder U8. The decoder U8 uses the chip 74LS74, and the first D flip-flop U11A Connect the low input terminal of the decoder U8, and the second D flip-flop U11B is connected to the high input terminal of the decoder U8. The decoder U8 converts the binary code output by the double D trigger counting module into decimal and displays it through the digital tube. , which can display the number of key presses of the non-self-locking key, and thus prompt the corresponding output status.

In this embodiment, the delay circuit is a 555 delay trigger circuit. The output end of the non-self-locking button is connected to the TRIG end of the 555 trigger circuit. It is a low-level trigger. After triggering, the timing starts until the non-self-locking button is released. After the button is released, the high level charges the charging capacitor C13 to a certain voltage, and then the output terminal of the 555 delay trigger circuit outputs a low level to trigger the output of the data latch circuit 74HCT573, thus achieving delay, 555 delay The delay time of the trigger circuit is jointly realized by the charging capacitor C13 and the adjustable resistor R7.

The battery charge and discharge comparison control module includes a first voltage hysteresis comparator U14A and a second voltage hysteresis comparator U14B, which are inverting voltage hysteresis comparators. The non-inverting input end of the first voltage hysteresis comparator U14A passes through the first resistor R1 Connect the positive terminal of the first reference voltage V _R1 , the first feedback resistor R2 is connected between its non-inverting input terminal and the output terminal, its reverse input terminal is connected to the positive terminal of the battery, and its output terminal is connected to the Zener diode ZD1. The non-inverting input terminal of the two voltage hysteresis comparators U14B is connected to the positive terminal of the second reference voltage V _R2 through the third resistor R3. A second feedback resistor R4 is connected between its non-inverting input terminal and the output terminal, and its inverse input terminal is connected to the positive terminal of the second reference voltage VR2. Connect the positive terminal of the battery, and its output terminal is connected to the Zener diode ZD2. The first reference voltage V _R1 is composed of the first adjustable DC power supply, and the second reference voltage V _R2 is composed of the second adjustable DC power supply;

The output end of the first voltage hysteresis comparator U14A is connected to the electromagnetic coil of the third relay through an NPN type composite transistor (composed of a cascade connection of NPN transistor Q3 and PNP transistor Q4). The charging indicator light is connected in parallel to both ends of the electromagnetic coil of the third relay. , the normally closed contact of the third relay is connected to the overcharge shutdown indicator LED10 and then connected in parallel to both ends of the charging input port IN1, and its normally open contact is connected to the charging circuit of the battery from the charging input port IN1; the second voltage hysteresis comparison The output end of the device U14B is connected to the electromagnetic coil of the fourth relay through an NPN type composite transistor (Q3, Q4). The over-discharge shutdown indicator LED10 is connected in parallel to both ends of the electromagnetic coil of the fourth relay. The normally closed contact of the fourth relay Connected to the discharge circuit of the battery to the load, the discharge indicator LED11 is connected to the normally closed contact of the fourth relay and then connected in parallel to both ends of the battery;

Since the output signal of the first voltage hysteresis comparator is too small to directly drive the third relay, Q3 and Q4 are used to form a composite transistor to drive the third relay (one end is connected to the positive end of the charging input port IN1, and the other end is connected to the emitter of Q4) To realize battery charging control, battery discharge control is similar;

The upper threshold voltage of the first voltage hysteresis comparator lower threshold voltage Where V _R1 is the above-mentioned first reference voltage, V _Z is the voltage stabilization value of the output Zener diode, let the upper threshold voltage V _p1 = overcharge shutdown voltage 14.5V, and the lower threshold voltage V _p2 = charge shutdown recovery voltage 13.5 V, then the ratio of the first resistor R1 and the first feedback resistor R2 and the required value of the first reference voltage V _R1 can be calculated;

In the characteristic curve, adjusting the value of the Zener diode ZD1 can move the characteristic curve of the first voltage hysteresis comparator up and down. The value of the Zener diode ZD1 can move the characteristic curve to the output high level 1 and low level 0. time value;

In the same way, the upper threshold voltage of the second voltage hysteresis comparator Lower threshold voltage/> Where V _R2 is the above-mentioned second reference voltage, V _Z is the voltage stabilization value of the output Zener diode, let the upper threshold voltage V _p1 = discharge shutdown recovery voltage 11.5V, and the lower threshold voltage V _p2 = over-discharge shutdown voltage 11V , then the ratio of the third resistor R3 and the second feedback resistor R4 and the required value of the second reference voltage V _R2 can be calculated;

In the same way, the value of the Zener diode ZD2 can move the characteristic curve of the second voltage hysteresis comparator to the value when it outputs high level 1 and low level 0;

The characteristic of the zener diode ZD1 is that when the output terminal of the first voltage hysteresis comparator outputs a high level, the high level is stabilized, and when the output terminal of the first voltage hysteresis comparator outputs a low level, the voltage is not stabilized. Low level has an impact, and the same applies to the Zener diode ZD2;

Therefore, it can be realized that when the terminal voltage of the battery is lower than the overcharge shutdown voltage of 14.5V, the first voltage hysteresis comparator U14A flips and outputs a low level. This low level causes the NPN type composite transistor to cut off. Specifically, The low level turns off the NPN transistor Q3, and the output of Q3 is high, which turns off the PNP transistor Q4. Therefore, the electromagnetic coil K3A of the third relay is not powered, and the normally open contact of the bidirectional switch K3B is disconnected, causing the charging input port IN1 to be disconnected. When the battery charging is turned on, the normally closed contact of K3B is closed, causing the overcharge shutdown indicator LED9 to light up. This overcharge shutdown state is maintained until the terminal voltage of the battery drops to the charge shutdown recovery voltage of 13.5V; thereafter, when When the terminal voltage of the battery drops to the charge shutdown recovery voltage of 13.5V, the first voltage hysteresis comparator U14A flips and outputs a high level. This high level causes the NPN type composite transistor to conduct. Specifically, the high level The NPN transistor Q3 is turned on, and Q3 outputs a low level, which turns the PNP transistor Q4 on. Then the electromagnetic coil K3A of the third relay is powered on, and the normally closed contact of K3B is disconnected, causing the overcharge shutdown indicator LED9 to turn off. Lights up, and the normally open contact of K3B closes, allowing the charging input port IN1 to resume charging the battery. When K3A is powered on, the charging indicator LED8 lights up. This charging state is maintained until the terminal voltage of the battery rises to the charging shutdown voltage. 14.5V;

Therefore, it can be realized that when the terminal voltage of the battery is higher than the discharge shutdown voltage of 11V, the second voltage hysteresis comparator U14B outputs a low level, and the low level causes the NPN type composite transistor to turn off, specifically, the NPN transistor Q5 turns off , Q5 outputs a high level, causing the PNP transistor Q6 to cut off, so the electromagnetic coil K4A of the fourth relay is not powered, and the normally closed contact of K4B is closed, turning on the battery to discharge the load, and the normally closed contact of K4B is also closed. The discharge indicator LED11 lights up, and the electromagnetic coil K4A of the fourth relay is not powered on so that the over-discharge shutdown indicator LED10 does not light up. This discharge state is maintained until the terminal voltage of the battery drops to the over-discharge shutdown voltage of 11V; when the battery's When the terminal voltage reaches the over-discharge shutdown voltage of 11V, the second voltage hysteresis comparator U14B flips and outputs a high level. This high level turns on the NPN type composite transistor. Specifically, the high level turns on the NPN transistor Q5. , Q5 outputs a low level, causing the PNP transistor Q6 to conduct, so the electromagnetic coil K4A of the fourth relay is powered on, and the normally closed contact of K4B is disconnected, disconnecting the battery from discharging to the load. When K4A is powered on, it also turns off the over-discharge The disconnection indicator LED10 lights up, and the disconnection of the normally closed contact of K4B also makes the discharge indicator LED11 not light up. This discharge shutdown state is maintained until the terminal voltage of the battery rises to the discharge shutdown recovery voltage of 12V. Among them, BT+ is connected to the positive terminal of the battery.

The first voltage hysteresis comparator U14A and the second voltage hysteresis comparator U14B are powered by the three-terminal adjustable voltage regulator U13. U13 uses the chip LM317. The input end of the LM317 is connected to the battery, which can achieve a stable voltage output when the input voltage changes. , adjusting RP5 can change the size of the output voltage. The output terminal VCC1 of LM317 is connected to the positive power supply terminals of the first and second voltage hysteresis comparators.

The charging input port IN1 of the battery charge and discharge comparison control module is connected to the output port OUT1 of the photovoltaic mains complementary combination logic control module. OUT2 in Figure 5 is the discharge port of the battery to the load.

The battery charge and discharge comparison control module connects a diode D0 to prevent current reverse charging between the charging input port IN1 and the battery to prevent the battery from discharging to the charging input port IN1. The positive terminal of the third relay is not connected to the positive terminal of the battery but to the positive terminal of the charging input port IN1, which can reduce the power consumption of the battery and save more power.

The following explains the working principle of the inverting voltage hysteresis comparator. Figure 6 is the circuit diagram of the reverse voltage hysteresis comparator. Figure 7 is the transmission characteristic diagram of the inverting voltage hysteresis comparator. Only when the input voltage reaches the upper limit of U, the inverting voltage hysteresis comparator outputs a low level. After that, the input voltage As long as it does not drop to the lower limit of U, it will continue to output a low level. Only when the input voltage drops to the lower limit of U, the inverting voltage hysteresis comparator will flip and output a high level. After that, as long as the input voltage does not rise to the upper limit of U, it will continue to output a high level. flat.

Figure 8 is a transmission characteristic diagram of the first voltage hysteresis comparator U14A in this embodiment, which forms a charging circuit, in which the upper limit of U is 14.5V and the lower limit of U is 13.5V. Figure 9 is a transmission characteristic diagram of the second voltage hysteresis comparator U14B in this embodiment, which constitutes a discharge circuit. In the diagram, the upper limit of U is 12V and the lower limit of U is 11V. Table 2 below shows the charging and discharging states corresponding to the battery voltage.

Table 2 Charging and discharging states corresponding to battery voltage

In this embodiment, as shown in Figure 10, the invention also includes a battery voltage acquisition and display module for collecting and displaying the terminal voltage of the battery, which uses the A/D conversion chip ICL7107 to connect both ends of the battery through a voltage acquisition circuit. , the voltage acquisition circuit is shown on the right side in Figure 10. The sampling point Test_in of the voltage sampling circuit is connected to the high input terminal of pin 31 of ICL7107. The output terminal of ICL7107 directly drives four LED digital tubes, and the decimal point is set through R29 , so that the display range is ±19.99, so the terminal voltage display of the battery with a nominal voltage of 12V can be realized. The four LED digital tubes are common anode LED digital tubes. The Test1 button is used to test the circuit signal integrity. When pressed, the LED digital tube outputs the character "1888".

The 36-pin reference voltage of ICL7107 needs to be calibrated to 100 millivolts by adjusting RP7. Pins 27, 28, and 29 are 0.22uF, 47kΩ, and 0.47uF resistor-capacitor networks, thereby achieving A/D conversion output. ICL7107 and LED digital tube constitute a digital voltmeter.

The power module is shown in Figures 11 and 12. The power module includes dual 15V power supplies and dual 5V power supplies. The dual 15V power supply is connected to the two three-terminal voltage regulators LM7815 through the transformer, rectifier and filter capacitor from the mains. They output +15V and -15V power respectively. When the output is normal, LED1 and LED2 light up. There is a gap between the rectifier and the filter capacitor. Control switch S2; Dual 5V power supply The ±15V power supply obtained from the dual 15V power supply is connected to two three-terminal voltage regulators LM7805 after filtering capacitors, which output +5V and -5V power supply respectively. When the output is normal, LED3 and LED4 light up, ± There is a control switch S3 between the 15V power supply and the filter capacitor.

In the present invention, the overcharge shutdown voltage, charge shutdown recovery voltage, discharge shutdown voltage, and discharge shutdown recovery voltage of the 12V battery are not limited to 14.5V, 13.5V, 11V, and 12V as described in the above embodiments, and can be within a certain range. Make adjustments within the range. For example, preferably, the overcharge shutdown voltage can be 14.1~14.5V, the charge shutdown recovery voltage can be 13.1~13.5V, the discharge shutdown voltage can be 10.8~11.5V, and the discharge shutdown recovery voltage can be 11.5~12V .

The above embodiments are merely enumerations of implementation forms of the technical concept of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent replacements and improvements made based on the technical concept of the present invention shall be included in the scope of protection of the present invention. .

Claims (10)

1. A12V storage battery photovoltaic commercial power complementary charge-discharge maintenance device is characterized in that: the photovoltaic power supply system comprises a power supply module, a photovoltaic commercial power complementary combination logic control module and a storage battery charge-discharge comparison control module, wherein the nominal voltage of the storage battery is 12V;

the power supply module comprises a double 15V power supply and a double 5V power supply; the double 15V power supply is connected with two three-terminal voltage regulators LM7815 after a commercial power passes through a transformer, a rectifier and a filter capacitor, and outputs +15V and-15V power supplies respectively; the + -15V power supply obtained by the double-15V power supply is connected with two three-terminal voltage regulators LM7805 after passing through a filter capacitor, and +5V power supply and-5V power supply are respectively output;

the photovoltaic commercial power complementary combination logic control module comprises a non-self-locking key, the non-self-locking key realizes binary addition counting of key times through a double-D trigger counting module, the output end of the non-self-locking key triggers a data latch circuit to output through a delay circuit, the output ends of two D triggers of the double-D trigger counting module are both connected with the data input end of the data latch circuit, one data output end of the data latch circuit is connected with a first relay through an optocoupler isolation circuit, a contact of the first relay can enable an output port OUT1 to be charged by a photovoltaic interface P1, the other data output end of the data latch circuit is connected with a second relay through the optocoupler isolation circuit, the contact of the second relay can enable the output port OUT1 to be charged by a commercial power interface P2, the output end levels of the two D triggers of the double-D trigger counting module can enable the output port OUT1 to be singly connected with the photovoltaic interface, one of the commercial power interface is simultaneously connected with the photovoltaic interface and the commercial power interface is charged, and the output port is not charged by the photovoltaic interface and the commercial power interface under a shutdown mode;

a first diode for preventing reverse current charging is connected between the photovoltaic interface P1 and the output port, a second diode for preventing reverse current charging is connected between the mains supply interface P2 and the output port, when the photovoltaic interface P1 and the mains supply interface P2 charge the output port at the same time, the first diode can prevent the reverse current of the mains supply interface when the mains supply charge is dominant, and the second diode can prevent the reverse current of the photovoltaic interface when the photovoltaic charge is dominant, so that the photovoltaic power supply or the mains supply is prevented from being damaged;

the storage battery charge-discharge comparison control module comprises a first voltage hysteresis comparator and a second voltage hysteresis comparator which are reverse-phase voltage hysteresis comparators, wherein the homodromous input end of the first voltage hysteresis comparator is connected with a first reference voltage V through a first resistor R1 _R1 A first feedback resistor R2 is connected between the same-direction input end and the output end, the reverse input end of the first feedback resistor is connected with the positive end of the storage battery, and the same-direction input end of the second voltage hysteresis comparator is connected with a second reference voltage V through a third resistor R3 _R2 A second feedback resistor R4 is connected between the same-direction input end and the output end, and the reverse input end of the second feedback resistor R4 is connected with the positive end of the storage battery; the output end of the first voltage hysteresis comparator is connected with the electromagnetic coil of the third relay through an NPN triode, the charging indicator lamp is connected in parallel with the two ends of the electromagnetic coil of the third relay, the normally closed contact of the third relay is connected with the over-charging turn-off indicator lamp and then connected in parallel with the two ends of the output port OUT1, and the normally open contact of the third relay is connected with the charging loop of the output port OUT1 to the storage battery; the output end of the second voltage hysteresis comparator is connected with the electromagnetic coil of the fourth relay through an NPN triode, the over-discharge turn-off indicator lamp is connected with the two ends of the electromagnetic coil of the fourth relay in parallel, the normally closed contact of the fourth relay is connected with the discharging loop of the storage battery to the load, and the discharging indicator lamp is connected with the normally closed contact of the fourth relay and then connected with the two ends of the storage battery in parallel;

upper threshold voltage of first voltage hysteresis comparatorLower threshold voltageWherein V is _R1 For the first reference voltage, V _Z For the voltage stabilizing value of the voltage stabilizing diode at the output end, the upper threshold voltage V _p1 =overcharge-off voltage, lower threshold voltage V _p2 The ratio of the first resistor R1 to the first feedback resistor R2 can be calculated to obtain the required first reference voltage V _R1 Is a numerical value of (2);

similarly, the upper threshold voltage of the second voltage hysteresis comparatorLower threshold voltageWherein V is _R2 For the second reference voltage, V _Z For the voltage stabilizing value of the voltage stabilizing diode at the output end, the upper threshold voltage V _p1 Discharge turn-off recovery voltage, lower threshold voltage V _p2 The ratio of the third resistor R3 to the second feedback resistor R4 can be calculated to obtain the required second reference voltage V _R2 Is a numerical value of (2);

when the terminal voltage of the storage battery rises to the over-charge turn-off voltage, the first voltage hysteresis comparator turns over to output a low level, the charging of the storage battery is disconnected through the NPN triode and the third relay, the over-charge turn-off indicator lamp is turned on at the moment, the over-charge turn-off state is maintained until the terminal voltage of the storage battery is reduced to the charge turn-off recovery voltage, the first voltage hysteresis comparator turns over to a high level when the charge turn-off recovery voltage is reached, and the charging of the storage battery is turned on, so that the charge indicator lamp is turned on at the moment; when the terminal voltage of the storage battery drops to the over-discharge turn-off voltage, the second voltage hysteresis comparator turns over to output a high level, the over-discharge turn-off indicator lamp is turned on at the moment when the second voltage hysteresis comparator turns off the discharge of the storage battery to the load through the NPN triode and the fourth relay, the over-discharge turn-off state is maintained until the terminal voltage of the storage battery reaches the discharge turn-off recovery voltage, the first voltage hysteresis comparator turns over to a low level when the discharge turn-off recovery voltage is reached, and the discharge indicator lamp is turned on at the moment.

2. The 12V battery photovoltaic utility power complementary charge-discharge maintenance device of claim 1, wherein: the first reference voltage V _R1 Is composed of the first adjustable DC power supply and the second reference voltage V _R2 Is composed of a second adjustable direct current power supply; the storage battery charge-discharge comparison control module is connected between the output port OUT1 and the storage battery through a diode D0 for preventing reverse charge of current, and the storage battery is prevented from discharging to the output port OUT1.

3. The 12V battery photovoltaic utility power complementary charge-discharge maintenance device according to claim 1 or 2, wherein: the double-D trigger counting module comprises a first D trigger and a second D trigger which are connected in cascade, wherein the clock end of the first D trigger is connected with the output end of the key anti-shake circuit, the D end of the first D trigger is connected with the reverse output end of the first D trigger, the D end of the second D trigger is connected with the reverse output end of the second D trigger, and the reverse output end of the first trigger is connected with the D end of the second D trigger, so that a binary addition counting module of an asynchronous clock is formed, wherein the second trigger is high-order output, and the first trigger is low-order output;

the reverse output end of the first D trigger and the reverse output end of the second D trigger of the double-D trigger counting module are connected with the data latch circuit, a data output end In0_out of the data latch circuit is connected with the first relay through the optocoupler isolation circuit and the PNP triode Q1, when the data output end In0_out of the data latch circuit outputs a low level, the PNP triode Q1 is conducted through the optocoupler isolation circuit, the first relay is electrified, and a normally open contact of the first relay is closed, so that the output port OUT1 is connected with the photovoltaic interface P1 for charging;

the other data output end In1_out of the data latch circuit is connected with a second relay through an optocoupler isolation circuit and a PNP triode Q2, when the data output end In1_out of the data latch circuit outputs a low level, the PNP triode Q2 is conducted through the optocoupler isolation circuit, the second relay is electrified, a normally open contact of the second relay is closed, and an output port OUT1 is connected with a mains interface P2 for charging;

when the data output terminal in0_out and the data output terminal in1_out of the data latch circuit U7 both output low level, it can be seen that the data latch circuit U7 can drive the first relay and the second relay to power up simultaneously, so that the photovoltaic interface P1 and the mains interface P2 supply power to the output port OUT1 simultaneously;

when the data output terminal in0_out and the data output terminal in1_out of the data latch circuit U7 both output a high level, this is IN the shutdown mode, and neither the photovoltaic interface nor the utility interface supplies power to the output port OUT1.

4. The 12V battery photovoltaic utility power complementary charge-discharge maintenance device of claim 1, wherein: the positive output ends of the first D trigger and the second D trigger of the double D triggers are connected with a decoder, the first D trigger is connected with the low-order input end of the decoder, the second D trigger is connected with the high-order input end of the decoder, the decoder converts an input binary code into decimal and displays the decimal through a nixie tube, and therefore the number of times of keys of the non-self-locking keys can be displayed.

5. The 12V battery photovoltaic utility power complementary charge-discharge maintenance device of claim 1, wherein: the system also comprises a storage battery voltage acquisition and display module, wherein the storage battery voltage acquisition and display module adopts an A/D conversion chip ICL7107, the storage battery voltage acquisition module is connected with two ends of a storage battery through a voltage acquisition circuit, a sampling point of the voltage acquisition circuit is connected with a high-order input end of the ICL7107, an output end of the ICL7107 directly drives four LED nixie tubes, a display range is enabled to be +/-19.99 by setting decimal point positions, terminal voltage display of the storage battery with a nominal voltage of 12V can be realized, and the ICL7107 and the LED nixie tubes form a digital voltmeter.

6. A 12V battery photovoltaic utility power complementary charge-discharge maintenance device as defined in claim 3, wherein: the non-self-locking key is a double-pole double-throw switch S1, one knife of the double-pole double-throw switch S1 is connected with the input end of the key anti-shake circuit, the other knife of the double-pole double-throw switch S1 is connected with the trigger end of the delay circuit, the two knives of the double-pole double-throw switch are linked, and the non-opening and closing end of the double-pole double-throw switch S1 is grounded;

the key anti-shake circuit is an RS trigger anti-shake circuit, the RS trigger anti-shake circuit is formed by connecting two NAND gates, and after the double-pole double-throw switch S1 is pressed and loosened, the output end of the RS trigger anti-shake circuit triggers the double-D trigger counting module to start working through rising edge level, and the first D trigger and the second D trigger of the double-D trigger counting module are both triggered by rising edge level;

the delay circuit adopts a 555 delay trigger circuit which starts delay for low level triggering until the charging capacitor C13 is charged to a certain voltage by the high level after the non-self-locking key is released, and the output end of the 555 delay trigger circuit can not output the low level so as to trigger the data latch circuit to output data, and the delay time of the 555 delay trigger circuit can be realized by adjusting the charging capacitor C13 and the adjustable resistor R7.

7. The 12V battery photovoltaic utility power complementary charge-discharge maintenance device of claim 2, wherein: the over-charge and off voltage of the storage battery is 14.1-14.5V, the charge and off recovery voltage is 13.1-13.5V, the over-discharge and off voltage is 10.8-12V, and the discharge and off recovery voltage is 11.5-12V.

8. The 12V battery photovoltaic utility power complementary charge-discharge maintenance device of claim 1, wherein: the NPN triode is a composite triode of NPN type and is formed by cascading an NPN triode and a PNP triode, when the input end is at a high level, the composite triode of NPN type is conducted, and when the input end is at a low level, the composite triode of NPN type is cut off.

9. The 12V battery photovoltaic utility power complementary charge-discharge maintenance device of claim 7, wherein: the over-charge and off-voltage of the storage battery is 14.5V, the charge and off-recovery voltage is 13.5V, the over-discharge and off-voltage is 11V, and the discharge and off-recovery voltage is 12V.

10. The 12V battery photovoltaic utility power complementary charge-discharge maintenance device of claim 6, wherein: the delay circuit adopts a chip NE555, the data latch circuit adopts a chip 74HC573, the double-D trigger adopts a chip 74LS74, and the decoder adopts a chip 74LS47.