A driving protection circuit to prevent solar panels from overcharging and reverse connection

Abstract

The present application relates to a driving protection circuit for preventing overcharging and reverse connection of solar panels, and relates to the field of driving protection circuits for solar panels, including solar terminals, battery terminals, load terminals and charging and discharging circuits, wherein the solar terminals provide PV voltage for the charging and discharging circuits; the charging and discharging circuits are electrically connected to the solar terminals, battery terminals and load terminals; the charging and discharging circuits include an anti-reverse connection unit, an anti-overcharge unit and a control unit; the solar terminals are electrically connected to the control unit through the anti-reverse connection unit and the anti-overcharge unit, the control unit is electrically connected to the battery terminals and the load terminals, and the anti-reverse connection unit and the anti-overcharge unit are connected in series; the anti-overcharge unit can prevent the PV voltage from being loaded onto the load terminals and the control unit. The present application has the effect of reducing the impact of the high voltage of solar energy on the load and the controller when the controller suddenly switches to discharge during the charging process.

Description

Technical Field

[0001] The present application relates to the field of driving protection circuits for solar panels, and more particularly to a driving protection circuit for preventing solar panels from being overcharged and reversely connected. Background Art

[0002] Solar controllers are used in solar photovoltaic systems to coordinate the work of solar panels, batteries, and loads. They are very important components in photovoltaic systems, making the entire solar photovoltaic system operate efficiently and safely. Solar street light controllers are mainly used in solar power supply systems such as homes, commercial areas, factories, transportation, pastoral areas, and communications.

[0003] During the day, the solar panels charge the batteries through the switch devices inside the controller; at night, the batteries light up the street lights through the switch devices inside the controller, and the switch devices are controlled by the main control chip and the half-bridge driver.

[0004] Regarding the above-mentioned related technologies, when the existing controller is discharging at night, if a solar panel is suddenly added or some customers need to confirm whether it is installed correctly after installation, they need to light the lamp during the day. At this time, if the discharge is suddenly switched during the charging process, the load and controller may be burned. Even if some driving and protection circuits include anti-reverse MOS, due to the body diode in the MOS tube, when discharging, a PV voltage higher than the load voltage is suddenly connected, and the PV voltage may burn the load and controller along the body diode of the anti-reverse MOS. Utility Model Content

[0005] In order to reduce the impact of the high voltage of solar energy on the load and the controller when the controller suddenly switches to discharge during the charging process, the present application provides a driving protection circuit that prevents solar panels from overcharging and reverse connection.

[0006] The present application provides a driving protection circuit for preventing solar panels from overcharging and reverse connection, which adopts the following technical solutions:

[0007] A driving protection circuit for preventing overcharging and reverse connection of a solar panel comprises a solar terminal, a battery terminal, a load terminal and a charging and discharging circuit, wherein the solar terminal provides a PV voltage for the charging and discharging circuit; the charging and discharging circuit is electrically connected to the solar terminal, the battery terminal and the load terminal; the charging and discharging circuit comprises an anti-reverse connection unit, an anti-overcharge unit and a control unit; the solar terminal is electrically connected to the control unit via the anti-reverse connection unit and the anti-overcharge unit, the control unit is electrically connected to the battery terminal and the load terminal, the anti-reverse connection unit and the anti-overcharge unit are connected in series; the anti-overcharge unit can prevent the PV voltage from being loaded onto the load terminal and the control unit.

[0008] By adopting the above technical solution, compared with the prior art, the charge-discharge circuit adds an anti-overcharge unit. At this time, when the discharge is suddenly switched during the charging process and the PV voltage is suddenly added, the anti-overcharge unit can prevent the PV voltage from being loaded onto the load terminal and the control unit. Due to the obstruction of the anti-overcharge unit, the PV voltage cannot be loaded onto the load voltage, thereby reducing the damage caused by the PV voltage to the load and the controller.

[0009] Optionally, the anti-reverse connection unit includes an anti-reverse connection control circuit, and the anti-overcharging unit includes an anti-overcharging control circuit. The anti-reverse connection control circuit and the anti-overcharging control circuit are electrically connected to MOS driving circuits respectively. The two MOS driving circuits respectively drive the anti-reverse connection control circuit and the anti-overcharging control circuit to operate. The anti-reverse connection control circuit and the anti-overcharging control circuit jointly control the on-off between the solar terminal and the control unit.

[0010] By adopting the above technical solution, the on and off of the anti-reverse connection control circuit and the anti-overcharge control circuit are respectively controlled by the MOS driving circuit. When the controller is in the discharging state, the anti-reverse connection control circuit and the anti-overcharge control circuit are both controlled by the MOS driving circuit to be in the off state, so that the PV voltage cannot be loaded on the load voltage, thereby protecting the load and the controller itself from the impact of the PV voltage.

[0011] Optionally, the MOS driving circuit includes a first transistor D1, the emitter of the first transistor D1 receives a control voltage; the collector of the first transistor D1 is connected to the anti-reverse connection control circuit or the anti-overcharge control circuit; and the base of the first transistor D1 is used to receive a control signal input from the outside.

[0012] By adopting the above technical solution, the triode, as the main component in the MOS drive circuit, can provide a higher drive current, which can speed up the switching speed and response speed. At the same time, the triode can generate a larger output signal under a smaller input signal, so that the triode drive circuit can provide a stable current and voltage output, thereby improving the efficiency and stability of the anti-reverse control circuit and the anti-overcharge control circuit.

[0013] Optionally, the two MOS drive circuits are electrically connected to a charge pump drive circuit, and the charge pump drive circuit is electrically connected to the solar terminal for receiving a drive signal input from the outside to provide a control voltage for the MOS drive circuit.

[0014] By adopting the above technical solution, the charge pump driving circuit can adjust the output voltage. By periodically charging and discharging the internal capacitor and utilizing the principle that the capacitor voltage cannot change suddenly, the input voltage can be controlled to obtain the required output voltage, thereby providing a more stable control voltage for the MOS driving circuit.

[0015] Optionally, the MOS driving circuit also includes a second transistor D2, the base of the first transistor D1 receives a control signal input from the outside through the second transistor D2; the emitter of the second transistor D2 is grounded; the collector of the second transistor D2 is electrically connected to the base of the first transistor D1; and the base of the second transistor D2 is used to receive a control signal input from the outside.

[0016] By adopting the above technical solution and the combined design of two transistors, the circuit can withstand higher voltage and current, thereby improving the stability and reliability of the circuit, reducing the risk of circuit damage due to excessive voltage or current, and achieving more precise and stable switching functions, thereby improving the stability and reliability of the MOS drive circuit.

[0017] Optionally, the charge pump drive circuit includes a driver A, an input pin of the driver A is used to receive a drive signal input from the outside, an output pin of the driver A is electrically connected to the solar terminal and the MOS drive circuit, and the driver A receives a PV voltage and provides a control voltage to the MOS drive circuit according to the PV voltage.

[0018] By adopting the above technical solution, a charge pump driving circuit is used to drive two MOS tubes at the same time, and a driving signal is input to raise the voltage of the bootstrap capacitor. A control voltage VD higher than the PV voltage is provided to the anti-reverse connection unit and the anti-overcharge unit according to the PV voltage, thereby improving the driving capability of the charge pump circuit.

[0019] Optionally, the output pin of the driver A is electrically connected to a resistor R10, one end of the resistor R10 is electrically connected to the output pin of the driver A, and the other end is electrically connected to a diode Z2, a diode Z3, a diode Z4 and a diode Z5, the cathode of the diode Z2 is electrically connected to a power supply, and the anode of the diode Z2 is electrically connected to the resistor R10; the cathode of the diode Z3 is electrically connected to the resistor R10, and the anode of the diode Z3 is grounded; the cathode of the diode Z4 is electrically connected to the resistor R10, the anode of the diode Z4 is electrically connected to the resistor R11, and the other end of the resistor R11 is electrically connected to the solar terminal; the anode of the diode Z5 is electrically connected to the resistor R10, the cathode of the diode Z5 is electrically connected to the resistor R12, and the other end of the resistor R12 is electrically connected to the MOS drive circuit.

[0020] By adopting the above technical solution, driver A provides a control voltage VD which is always higher than the PV voltage at a fixed level to the MOS driving circuit through the design of the peripheral circuit, thereby ensuring that driver A has sufficient driving capability to drive two MOS to work simultaneously.

[0021] Optionally, the first transistor D1 is a PNP transistor; the second transistor D2 is an NPN transistor.

[0022] By adopting the above technical solution, the PNP transistor and the NPN transistor are interconnected to form a MOS drive circuit. The two transistors are interconnected to form a complementary control circuit, which effectively suppresses noise and interference in the circuit and improves the stability of the circuit. The combination of the two transistors can generate a larger current and voltage output and obtain a higher driving capability.

[0023] In summary, the present application includes at least one of the following beneficial technical effects:

[0024] 1. Compared with the prior art, the charge-discharge circuit is equipped with an anti-overcharge unit. When the discharge is suddenly switched during the charging process and the PV voltage is suddenly added, the anti-overcharge unit can prevent the PV voltage from being loaded onto the load terminal and the control unit. Due to the barrier of the anti-overcharge unit, the PV voltage cannot be loaded onto the load voltage, thereby reducing the damage caused by the PV voltage to the load and the controller;

[0025] 2. This solution uses a charge pump drive circuit to drive two MOS tubes at the same time, and inputs a drive signal to raise the voltage of the bootstrap capacitor. According to the PV voltage, a control voltage that is always higher than the PV voltage is provided to the anti-reverse connection unit and the anti-overcharge unit, ensuring that the driver has sufficient driving capability to drive the two MOS tubes to work at the same time, thereby improving the driving capability of the charge pump circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a module schematic diagram of an embodiment of the present application.

[0027] Figure 2 It is a module schematic diagram of an anti-overcharge unit and an anti-reverse connection unit in an embodiment of the present application.

[0028] Figure 3 is a circuit diagram of a MOS driving circuit according to an embodiment of the present application.

[0029] Figure 4 is a circuit diagram of a charge pump driving circuit according to an embodiment of the present application.

[0030] Explanation of the accompanying drawings: 1. Solar terminal; 2. Battery terminal; 3. Load terminal; 4. Charging and discharging circuit; 41. Anti-overcharging unit; 411. Anti-overcharging control circuit; 42. Anti-reverse connection unit; 421. Anti-reverse connection control circuit; 43. Control unit; 44. MOS driving circuit; 45. Charge pump driving circuit. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of this application more clear, the following Figure 1-4 It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0032] The present application embodiment discloses a driving protection circuit for preventing overcharging and reverse connection of a solar panel. Figure 1 A driving protection circuit for preventing solar panels from overcharging and reverse connection includes a solar terminal 1, a battery terminal 2, a load terminal 3 and a charging and discharging circuit 4. The charging and discharging circuit 4 is electrically connected to the solar terminal 1, the battery terminal 2 and the load terminal 3. The solar terminal 1 provides a PV voltage to the charging and discharging circuit 4. During the day, the solar panel charges the battery through the charging and discharging circuit 4; at night, the battery lights up the street lamp through the charging and discharging circuit 4.

[0033] Reference Figure 1 , the charge-discharge circuit 4 includes an anti-reverse connection unit 42, an anti-overcharge unit 41 and a control unit 43; the anti-reverse connection unit 42 and the anti-overcharge unit 41 are connected in series, the solar terminal 1 is electrically connected to the control unit 43 through the anti-reverse connection unit 42 and the anti-overcharge unit 41, and the control unit 43 is electrically connected to the battery terminal 2 and the load terminal 3. Compared with the prior art, the charge-discharge circuit 4 adds an anti-overcharge unit 41. At this time, when the discharge is suddenly switched during the charging process and the PV voltage is suddenly added, the anti-overcharge unit 41 can prevent the PV voltage from being loaded on the load terminal 3 and the control unit 43. Due to the obstruction of the anti-overcharge unit 41, the PV voltage cannot be loaded on the load voltage, thereby reducing the damage caused by the PV voltage to the load and the controller.

[0034] Reference Figure 2 The overcharge prevention unit 41 includes an overcharge prevention control circuit 411, which includes a MOS tube Q1. The drain of the MOS tube Q1 is electrically connected to the solar terminal 1 to receive the PV voltage; the source of the MOS tube Q1 is electrically connected to the anti-reverse connection unit 42; the gate of the MOS tube Q1 is electrically connected to a resistor R1 and a resistor R2, one end of the resistor R1 is electrically connected to the MOS tube Q1, and the other end is electrically connected to the MOS driving circuit 44, one end of the resistor R2 is electrically connected to the gate of the MOS tube Q1, and the other end is electrically connected to the source of the MOS tube Q1.

[0035] Reference Figure 2The anti-reverse connection unit 42 includes an anti-reverse connection control circuit 421, and the anti-overcharge control circuit 411 includes a MOS tube Q2, the drain of the MOS tube Q2 is electrically connected to the control unit 43; the source of the MOS tube Q2 is electrically connected to the anti-overcharge unit 41; the gate of the MOS tube Q2 is electrically connected to a resistor R3 and a resistor R4, one end of the resistor R3 is electrically connected to the MOS tube Q2, and the other end is electrically connected to the MOS driving circuit 44, one end of the resistor R4 is electrically connected to the gate of the MOS tube Q2, and the other end is electrically connected to the source of the MOS tube Q2.

[0036] The two MOS driving circuits 44 respectively drive the anti-reverse connection control circuit 421 and the anti-overcharge control circuit 411 to operate, and the anti-reverse connection control circuit 421 and the anti-overcharge control circuit 411 jointly control the connection between the solar terminal 1 and the control unit 43 .

[0037] Reference Figure 3 , the MOS driving circuit 44 includes a first transistor D1 and a second transistor D2, the first transistor D1 is a PNP transistor, and the second transistor D2 is an NPN transistor. The emitter of the first transistor D1 is electrically connected to the charge pump driving circuit 45, and receives the control voltage VD output by the charge pump driving circuit 45. The collector of the first transistor D1 is electrically connected to the anti-reverse connection control circuit 421 or the anti-overcharge control circuit 411. The base of the first transistor D1 is electrically connected to a resistor R5 and a diode Z1, the other end of the resistor R5 is electrically connected to the emitter of the first transistor D1, the anode of the diode Z1 is electrically connected to the base of the first transistor D1, the cathode of the diode Z1 is electrically connected to a resistor R6, and the other end of the resistor R6 is electrically connected to the collector of the second transistor D2. The emitter of the second transistor D2 is electrically connected to a resistor R7, the other end of the resistor R7 is grounded, the base of the second transistor D2 is electrically connected to a resistor R8, the other end of the resistor R8 is grounded, and the base of the second transistor D2 receives a control signal Ctrl input from the outside.

[0038] Reference Figure 4The charge pump driving circuit 45 includes a driver A, which is preferably EG27324. An input pin of the driver A is electrically connected to a resistor R9, and the other end of the resistor R9 receives a driving signal Trig input from the outside. The output pin of driver A is electrically connected to resistor R10, one end of resistor R10 is electrically connected to the output pin of driver A, and the other end is electrically connected to diode Z2, diode Z3, diode Z4 and diode Z5, the cathode of diode Z2 is electrically connected to power supply +12V, and the anode of diode Z2 is electrically connected to resistor R10; the cathode of diode Z3 is electrically connected to resistor R10, and the anode of diode Z3 is grounded; the cathode of diode Z4 is electrically connected to resistor R10, and the anode of diode Z4 is electrically connected to resistor R11, the other end of resistor R11 is electrically connected to solar terminal 1 to receive PV voltage, and is electrically connected to resistor R13 and capacitor C1; the anode of diode Z5 is electrically connected to resistor R10, and the cathode of diode Z5 is electrically connected to resistor R12, the other end of resistor R12 is electrically connected to the anti-reverse connection unit 42 and the anti-overcharge unit 41, outputs control voltage VD, and is electrically connected to the other end of resistor R13 away from resistor R11 and the other end of capacitor C1 away from resistor R11.

[0039] This embodiment uses a charge pump driving circuit 45 to drive two MOS tubes at the same time. A driving chip is used to input a 30khz driving signal Trig, receive a PV voltage, and raise the voltage of the bootstrap capacitor. According to the PV voltage, a control voltage VD higher than the PV voltage is provided to the anti-reverse connection unit 42 and the anti-overcharge unit 41 to drive the two MOS to work. The driving voltage obtained by this circuit is more stable.

[0040] The implementation principle of a driving protection circuit for preventing overcharging and reverse connection of a solar panel in an embodiment of the present application is as follows: the charge pump driving circuit 45 always provides a MOS driving circuit 44 with a high and stable PV voltage control voltage VD to ensure the stable operation of the MOS driving circuit 44. When the controller is in a charging state (i.e., when the solar energy charges the battery through the controller), the two MOS control circuits receive control signals input from the outside, and control the MOS tube Q1 and the MOS tube Q2 to be turned on according to the control signals, so that the solar energy charges the battery through the controller. When the controller is in a discharging state (i.e., when the battery provides the load with the electric energy required for lighting through the controller), the two MOS control circuits control the MOS tube Q1 and the MOS tube Q2 to be turned off according to the control signals, and disconnect the connection between the solar terminal 1 and the control unit 43. If the discharge is suddenly switched at this time, due to the shutdown of the MOS tube Q1 and the MOS tube Q2, the PV voltage cannot be directly loaded on the load terminal 3 and the control unit 43, and the MOS tube Q1 and the MOS tube Q2 play a blocking role, thereby reducing the damage caused by the PV voltage to the load and the controller.

[0041] The above are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Any feature disclosed in this specification (including the abstract and drawings), unless otherwise stated, can be replaced by other equivalent or alternative features with similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

Claims

1. A driving protection circuit for preventing solar panels from overcharging and reverse connection, characterized in that: It comprises a solar terminal (1), a battery terminal (2), a load terminal (3) and a charging and discharging circuit (4), wherein the solar terminal (1) provides a PV voltage for the charging and discharging circuit (4); The charging and discharging circuit (4) is electrically connected to the solar terminal (1), the battery terminal (2), and the load terminal (3); the charging and discharging circuit (4) comprises an anti-reverse connection unit (42), an anti-overcharge unit (41), and a control unit (43); the solar terminal (1) is electrically connected to the control unit (43) via the anti-reverse connection unit (42) and the anti-overcharge unit (41); the control unit (43) is electrically connected to the battery terminal (2) and the load terminal (3); the anti-reverse connection unit (42) and the anti-overcharge unit (41) are connected in series; the anti-overcharge unit (41) can prevent the PV voltage from being loaded onto the load terminal (3) and the control unit (43).

2. A driving protection circuit for preventing overcharging and reverse connection of a solar panel according to claim 1, characterized in that: The anti-reverse connection unit (42) comprises an anti-reverse connection control circuit (421), and the anti-overcharging unit (41) comprises an anti-overcharging control circuit (411). The anti-reverse connection control circuit (421) and the anti-overcharging control circuit (411) are respectively electrically connected to a MOS driving circuit (44). The two MOS driving circuits (44) respectively drive the anti-reverse connection control circuit (421) and the anti-overcharging control circuit (411) to operate. The anti-reverse connection control circuit (421) and the anti-overcharging control circuit (411) jointly control the on-off between the solar terminal (1) and the control unit (43).

3. A driving protection circuit for preventing solar panels from overcharging and reverse connection according to claim 2, characterized in that: The MOS drive circuit (44) comprises a first transistor D1, the emitter of the first transistor D1 receives a control voltage; the collector of the first transistor D1 is connected to the anti-reverse connection control circuit (421) or the anti-overcharge control circuit (411); and the base of the first transistor D1 is used to receive a control signal input from the outside.

4. A driving protection circuit for preventing solar panels from overcharging and reverse connection according to claim 2, characterized in that: The two MOS drive circuits (44) are electrically connected to a charge pump drive circuit (45) in common. The charge pump drive circuit (45) is electrically connected to the solar terminal (1) and is used to receive a drive signal input from the outside and provide a control voltage for the MOS drive circuit (44).

5. A driving protection circuit for preventing solar panels from overcharging and reverse connection according to claim 3, characterized in that: The MOS driving circuit (44) further comprises a second transistor D2, the base of the first transistor D1 receives a control signal input from the outside through the second transistor D2; the emitter of the second transistor D2 is grounded; the collector of the second transistor D2 is electrically connected to the base of the first transistor D1; and the base of the second transistor D2 is used to receive a control signal input from the outside.

6. A driving protection circuit for preventing solar panels from overcharging and reverse connection according to claim 4, characterized in that: The charge pump drive circuit (45) comprises a driver A, wherein an input pin of the driver A is used to receive a drive signal input from the outside, an output pin of the driver A is electrically connected to the solar terminal (1) and the two MOS drive circuits (44), and the driver A receives a PV voltage and provides a control voltage to the two MOS drive circuits (44) according to the PV voltage.

7. A driving protection circuit for preventing solar panels from overcharging and reverse connection according to claim 6, characterized in that: The output pin of the driver A is electrically connected to a resistor R10, one end of the resistor R10 is electrically connected to the output pin of the driver A, and the other end is electrically connected to a diode Z2, a diode Z3, a diode Z4 and a diode Z5, the cathode of the diode Z2 is electrically connected to a power supply, and the anode of the diode Z2 is electrically connected to the resistor R10; the cathode of the diode Z3 is electrically connected to the resistor R10, and the anode of the diode Z3 is grounded; the cathode of the diode Z4 is electrically connected to the resistor R10, the anode of the diode Z4 is electrically connected to the resistor R11, and the other end of the resistor R11 is electrically connected to the solar terminal (1); the anode of the diode Z5 is electrically connected to the resistor R10, the cathode of the diode Z5 is electrically connected to the resistor R12, and the other end of the resistor R12 is electrically connected to the two MOS drive circuits (44).

8. A driving protection circuit for preventing solar panels from overcharging and reverse connection according to claim 5, characterized in that: The first transistor D1 is a PNP transistor; the second transistor D2 is an NPN transistor.

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