CN117410933B

CN117410933B - Overvoltage protection circuit and energy storage power supply

Info

Publication number: CN117410933B
Application number: CN202311675370.0A
Authority: CN
Inventors: 雷健华; 游永亮; 黎香壮; 唐朝垠; 张蒙
Original assignee: Shenzhen Delian Minghai New Energy Co ltd
Current assignee: Shenzhen Delian Minghai New Energy Co ltd
Priority date: 2023-12-08
Filing date: 2023-12-08
Publication date: 2024-05-17
Anticipated expiration: 2043-12-08
Also published as: CN117410933A

Abstract

The embodiment of the application relates to an overvoltage protection circuit and an energy storage power supply. The overvoltage protection circuit is arranged on a power supply line, and a relay is arranged on the power supply line; the relay control module is configured to: when the first control signal is received, the relay is controlled to be closed; and when receiving the second control signal, controlling the relay to be disconnected; the overvoltage detection module is configured to: when the input voltage on the power supply line is greater than a preset threshold value, outputting an overvoltage signal; the overvoltage control module is configured to: when the overvoltage signal is received, the pre-charging module is controlled to be in an off state, and the control signal received by the relay control module is locked to the second control signal. The overvoltage protection circuit detects the input voltage of the power supply line, when the input voltage overvoltage is detected, the pre-charging module is turned off in time, and the relay on the power supply line is forcibly turned off, so that the power on of the later-stage circuit is turned off, and the later-stage circuit is further protected.

Description

Overvoltage protection circuit and energy storage power supply

Technical Field

The present disclosure relates to electronic circuits, and particularly to an overvoltage protection circuit and an energy storage power supply.

Background

Solar energy is becoming an important energy source for human beings, and particularly, the solar energy is relatively easy to obtain, has low exploitation and utilization cost, and is the most widely used new clean energy source. Solar energy is converted into electric energy by photoelectric direct conversion and utilizing photoelectric effect. New energy products currently using solar energy are also under high-speed development, such as solar inversion, energy storage products, and the like.

However, the output voltages provided by the solar panels produced by different manufacturers are different, which easily causes that the products matched with the solar panels are connected with too high voltage, thereby causing damage to the matched products.

Disclosure of Invention

The invention provides an overvoltage protection circuit and an energy storage power supply, which are used for detecting input voltage and turning off the power on of a later-stage circuit when the input voltage is overvoltage.

In a first aspect, an embodiment of the present application provides an overvoltage protection circuit, where the overvoltage protection circuit is disposed on a power supply line, and a relay is disposed on the power supply line, and the overvoltage protection circuit includes an overvoltage detection module, a pre-charging module, an overvoltage control module, and a relay control module; the overvoltage detection module is respectively connected with the power supply circuit and the overvoltage control module, the overvoltage control module is also connected with the pre-charging module and the relay control module, and the relay control module is also connected with the relay; the relay control module is configured to: when a first control signal is received, the relay is controlled to be closed; and when receiving a second control signal, controlling the relay to be disconnected; the overvoltage detection module is configured to: when the input voltage on the power supply line is greater than a preset threshold value, outputting an overvoltage signal; the overvoltage control module is configured to: and when the overvoltage signal is received, controlling the pre-charging module to be in a disconnected state, and locking the control signal received by the relay control module to the second control signal.

Optionally, the overvoltage detection module includes: a first switching unit and an overvoltage detection unit; one end of the overvoltage detection unit is connected with the power supply circuit, the other end of the overvoltage detection unit is connected with the first switch unit, and the first switch unit is also connected with the pre-charging module and the relay control module respectively; the overvoltage detection unit is configured to: outputting an overvoltage detection signal when the input voltage on the power supply line is greater than the preset threshold value; the first switching unit is configured to: when the overvoltage detection signal is received, the first switch unit is turned on to output the overvoltage signal through the first switch unit.

Optionally, the overvoltage control module is further configured to: when the overvoltage signal is received, the pre-charging module is controlled to be in a disconnected state, and meanwhile, the electric energy stored in the pre-charging module is discharged.

Optionally, the overvoltage control module includes: a second switching unit and a third switching unit; the second switch unit is respectively connected with the third switch unit, the pre-charging module and the relay control module, and the third switch unit is respectively connected with the overvoltage detection module and the pre-charging module; the third switching unit is configured to: when the overvoltage signal is received, the third switch unit is conducted so as to output the overvoltage signal through the third switch unit, and the pre-charging module is controlled to be in an off state; the second switching unit is configured to: when the overvoltage signal is received, the second switch unit is conducted, so that the control signal received by the relay control module is locked on the second control signal through the second switch unit, and the electric energy stored in the pre-charging module is discharged.

Optionally, the second switching unit includes: transistor Q1, resistor R1 and resistor R2; the collector electrode of the triode Q1 is respectively connected with the pre-charging module and the relay control module; the base electrode of the triode Q1 is connected with one end of the resistor R1, and the other end of the resistor R1 is connected with the third switch unit; the base electrode of the triode Q1 is connected with one end of the resistor R2, and the other end of the resistor R2 is connected to the ground; the emitter of the transistor Q1 is connected to ground.

Optionally, the third switching unit includes: transistor Q2 and resistor R3; the base electrode of the triode Q2 is respectively connected with the overvoltage detection module and one end of the resistor R3, and the other end of the resistor R3 is connected with the power supply circuit; the collector electrode of the triode Q2 is respectively connected with the second switch unit and the pre-charging module; and the emitter of the triode Q2 is connected with the power supply circuit.

Optionally, the pre-charging module comprises a pre-charging switch unit and a pre-charging time unit which are connected with each other, and the over-voltage control module is also connected with the pre-charging switch unit and the pre-charging time unit respectively; the overvoltage control module is configured to: when the overvoltage signal is received, the pre-charging switch unit is controlled to be in an off state, and meanwhile, the electric energy stored in the pre-charging time unit is discharged.

Optionally, the pre-charging time unit includes: a capacitor C1 and a resistor R4; the first end of the resistor R4 is respectively connected with the first output end of the overvoltage control module and the pre-charging switch unit, the second end of the resistor R4 is respectively connected with the second output end of the overvoltage control module and the first end of the capacitor C1, and the second end of the capacitor C1 is grounded; the overvoltage control module is configured to: when the overvoltage signal is received, the pre-charging switch unit is controlled to be in an off state, and meanwhile, the electric energy stored in the capacitor C1 is discharged.

Optionally, the pre-charging time unit further includes: a diode D1; the positive pole of diode D1 is connected with the first end of electric capacity C1 and the second end of resistance R4 respectively, the negative pole of diode D1 is connected with the second output of overvoltage control module.

Optionally, the relay control module includes: a fourth switching unit, a diode D3 and a control signal input terminal; the control end of the fourth switch unit is respectively connected with the control signal input end and the positive electrode of the diode D3, and the negative electrode of the diode D3 is connected with the overvoltage control module; the connecting end of the fourth switch unit is connected with the coil end of the relay; the overvoltage control module is configured to: when the overvoltage signal is received, the control signal received by the control signal input end is connected to the ground through the diode D3, so that the control signal received by the fourth switch unit is locked on the second control signal.

Optionally, the fourth switching unit includes: transistor Q3, resistor R5 and resistor R6; the base electrode of the triode Q3 is respectively connected with one end of the resistor R5 and one end of the resistor R6, the other end of the resistor R5 is respectively connected with the control signal input end and the positive electrode of the diode D3, and the other end of the resistor R6 is connected to the ground; the collector electrode of the triode Q3 is connected with the coil end of the relay; the emitter of the transistor Q3 is connected to ground.

Optionally, an input end of the power supply line is connected with a solar panel.

In a second aspect, embodiments of the present application provide an energy storage power supply comprising an overvoltage protection circuit as described above.

At least one advantageous aspect of the overvoltage protection circuit provided by the embodiment of the application is that: the input voltage of the power supply line is detected through the overvoltage detection module, when the input voltage overvoltage is detected, the overvoltage control module is used for controlling the pre-charging module to be turned off, and the control signal received by the relay control module is locked into the second control signal, so that the relay on the power supply line is forcibly turned off, the power on of the later-stage circuit is turned off, the later-stage circuit is protected, the damage of the product connected with the solar panel due to the fact that the solar panel is not matched with the later-stage circuit due to the fact that the solar panel outputs too high voltage is avoided, in addition, the circuit components are fewer, and the design cost of the whole circuit is low.

Drawings

One or more embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which the figures of the drawings are not to be taken in a limiting sense, unless otherwise indicated.

FIG. 1 is a functional block diagram of an energy storage power supply according to an embodiment of the present application;

FIG. 2 is a functional block diagram of an overvoltage protection circuit provided in an embodiment of the present application;

FIG. 3 is a functional block diagram of an overvoltage protection circuit provided in another embodiment of the present application;

Fig. 4 is a schematic diagram of an overvoltage protection circuit according to an embodiment of the present application.

Detailed Description

In order that the invention may be readily understood, a more particular description thereof will be rendered by reference to specific embodiments that are illustrated in the appended drawings. It will be understood that when an element is referred to as being "fixed" to another element, it can be directly on the other element or one or more intervening elements may be present therebetween. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or one or more intervening elements may be present therebetween. The terms "upper," "lower," "inner," "outer," "bottom," and the like as used in this specification are used in an orientation or positional relationship based on that shown in the drawings, merely to facilitate the description of the invention and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the invention. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used in this specification includes any and all combinations of one or more of the associated listed items.

In addition, the technical features mentioned in the different embodiments of the invention described below can be combined with one another as long as they do not conflict with one another.

The pre-charging circuit is a circuit for charging the bus capacitor at the initial stage of system power-on, and generally, current limiting and pre-charging are performed through a pre-charging resistor so as to prevent the damage of the components caused by surge current generated when the bus capacitor is not fully charged.

Fig. 1 is a functional block diagram of an energy storage power supply according to an embodiment of the present application, which may determine a specific implementation form according to a practical application scenario, for example, a power supply output by a solar panel. As shown in fig. 1, the energy storage power supply includes: a voltage source Power and an overvoltage protection circuit 10. The stored energy power source is capable of providing power to the load 20.

The voltage source Power is an energy source capable of continuously providing Power. Any suitable implementation manner may be selected according to the actual situation, so as to provide the required target voltage, for example, the Power output by the solar panel, and in other embodiments, the voltage source Power may be external and Power is supplied through a specific interface.

The overvoltage protection circuit 10 is a circuit capable of detecting a voltage of a power supply line of an energy storage power supply, and when an input voltage on the power supply line does not exceed a preset threshold value, the energy storage power supply keeps energization to a subsequent stage circuit (load); when the input voltage on the power supply line exceeds a preset threshold, the energization of the subsequent stage circuit (load) is turned off.

The load 20 refers to any type of portion that requires power to be consumed to perform a corresponding function, including but not limited to a main controller or a power management system. For example, the load may be an energy storage battery, and the power source output by the solar panel powers the energy storage battery. For another example, the load may be a product matched with a solar panel, or may be a photovoltaic inverter. The load 20 corresponds to an input voltage of the voltage source, and when the input voltage does not exceed a preset threshold, the load 20 consumes electric energy, and when the input voltage exceeds the preset threshold, the load 20 stops operating due to the turn-off of the input voltage by the overvoltage protection circuit 10.

It should be noted that, for simplicity and convenience of presentation, the embodiment of the application exemplarily shows an application scenario of the overvoltage protection circuit in a new solar energy product. However, it will be appreciated by those skilled in the art that the overvoltage protection circuit provided in the embodiments of the present application can be applied to other electronic circuit scenarios requiring overvoltage detection and protection based on similar principles. The inventive concept disclosed in the embodiments of the present application is not limited to application to the energy storage power supply shown in fig. 1, but may be used in other similar electronic circuits.

Fig. 2 is a functional block diagram of an overvoltage protection circuit provided in an embodiment of the present application. The overvoltage protection circuit can be applied to the energy storage power supply shown in fig. 1, and protection of the circuit is realized.

As shown in fig. 2, the overvoltage protection circuit 10 may include: an overvoltage detection module 110, a pre-charge module 120, an overvoltage control module 130, and a relay control module 140.

The overvoltage protection circuit 10 is provided on a power supply line, and a relay 30 is provided on the power supply line.

The overvoltage detection module 110 is connected with the power supply line and the overvoltage control module 130, the overvoltage control module 130 is also connected with the pre-charging module 120 and the relay control module 140, and the relay control module 140 is also connected with the relay 30.

It should be noted that the pre-charge module 120 is connected to a power supply line. In an embodiment, the power supply line is a photovoltaic power supply line, that is, the power supply line is connected to the photovoltaic input source, and the overvoltage protection circuit provided in this embodiment is used for protecting input overvoltage of the photovoltaic input source. In one embodiment, the photovoltaic input source may be a power source for the output of a solar panel.

The relay control module 140 is configured to control the closing or opening of the relay 30, the relay control module 140 being configured to: upon receiving the first control signal, the control relay 30 is closed; and upon receiving the second control signal, the control relay 30 is turned off. It should be noted that the first control signal is used for indicating an electrical signal with a voltage value greater than or equal to a first preset value, and the second control signal is used for indicating an electrical signal with a voltage value less than or equal to a second preset value, wherein the first preset value is greater than the second preset value. By way of example and not limitation, the first preset value may be 3 volts (V), may also be 4 volts (V), and is not limited herein, and the second preset value may be 0.5 volts (V), may also be 1 volt (V), and is not limited herein, as long as the first preset value is greater than the second preset value. In one embodiment, the first control signal is a high level signal and the second control signal is a low level signal.

The overvoltage detection module 110 is configured to detect an input voltage on a power supply line, and the overvoltage detection module 110 is configured to: and outputting an overvoltage signal when the input voltage on the power supply line is greater than a preset threshold value. By way of example and not limitation, the preset threshold may be 50 volts (V) or 60 volts (V), and the specific preset threshold may be set according to practical application requirements, which is not limited herein.

The overvoltage control module 130 is configured to control the pre-charge module 120 and the relay control module 140, the overvoltage control module 130 being configured to: upon receiving the over-voltage signal, the pre-charge module 120 is controlled to be in an off state, and the control signal received by the relay control module 140 is locked to the second control signal, so that the relay control module 140 controls the relay 30 to be turned off.

At least one advantageous aspect of the overvoltage protection circuit provided in the embodiments of the present application is: the input voltage of the power supply circuit is detected through the overvoltage detection module, when the overvoltage of the input voltage is detected, the pre-charging module is controlled to be turned off through the overvoltage control module, and a control signal received by the relay control module is locked into a second control signal so as to forcibly turn off a relay on the power supply circuit, thereby turning off the power on of a later-stage circuit, protecting the later-stage circuit and avoiding the damage of the product connected with the solar panel due to the fact that the excessive voltage is output by an incompatible solar panel.

Fig. 3 is a functional block diagram of an overvoltage protection circuit provided in another embodiment of the present application. The overvoltage protection circuit can be applied to the energy storage power supply shown in fig. 1, and protection of the circuit is realized.

In some embodiments, as shown in fig. 3, the overvoltage detection module 110 includes: a first switching unit 111 and an overvoltage detection unit 112.

One end of the overvoltage detection unit 112 is connected to a power supply line, the other end of the overvoltage detection unit 112 is connected to the first switch unit 111, and the first switch unit 111 is further connected to the pre-charging module 120 and the relay control module 140, respectively.

The overvoltage detection unit 112 is configured to detect an input voltage on a power supply line, and the overvoltage detection unit 112 is configured to: and outputting an overvoltage detection signal when the input voltage on the power supply line is greater than a preset threshold value.

The first switching unit 111 is configured to: when receiving the overvoltage detection signal, the first switching unit 111 is turned on to output the overvoltage signal through the first switching unit 111.

In some embodiments, as shown in fig. 3, the overpressure control module 130 is further configured to: when the overvoltage signal is received, the precharge module 120 is controlled to be in an off state, and at the same time, the electric energy stored in the precharge module 120 is discharged.

It should be noted that, the pre-charging module is generally provided with a delay capacitor as a delay turn-off device, and is used for charging the delay capacitor by the input electric energy on the power supply line at the initial stage of system power-up, and driving the pre-charging switch to conduct for pre-charging, and driving the pre-charging switch to break after the delay capacitor is fully charged, so as to stop the pre-charging. Thus, automatic switching from pre-charging to normal power supply can be realized.

In this embodiment, the discharging of the stored electric energy of the pre-charging module 120 refers to the discharging of the electric energy of the delay capacitor in the pre-charging module.

In some embodiments, as shown in fig. 3, the overvoltage protection circuit is connected to the load 20 via a supply line, wherein a busbar capacitance EC1 is provided on the supply line.

It is understood that when the power supply line is connected with the photovoltaic input source, as the output voltage of the solar panel changes along with the illumination intensity, the higher the illumination is, the weaker the illumination is, and the lower the output voltage is. When overvoltage protection occurs, the relay and the pre-charging module are in an off state, and the electric energy of the bus capacitor EC1 can be discharged, so that when the system is recovered to work normally, the pre-charging needs to be performed again. In this embodiment, when the voltage output by the solar panel is converted from the overvoltage state to the normal power supply state (for example, when the illumination intensity is weakened), the pre-charging module can be ensured to work normally to perform pre-charging by discharging the electric energy stored in the pre-charging module 120 when the overvoltage protection is received. Therefore, on one hand, the solar panel which is not matched with the solar panel can also provide electric energy for products, so that the solar panel can supply power for loads when normal power supply voltage is input, the energy utilization rate is improved, and on the other hand, when the overvoltage state is converted into the normal power supply state, the pre-charging module can be ensured to work normally for pre-charging.

In some embodiments, as shown in fig. 3, the overpressure control module 130 includes: a second switching unit 131 and a third switching unit 132.

The second switch unit 131 is connected to the third switch unit 132, the pre-charging module 120, and the relay control module 140, and the third switch unit 132 is connected to the over-voltage detection module 110 and the pre-charging module 120.

The third switching unit 132 is used for controlling the pre-charging module 120, and the third switching unit 132 is configured to: when receiving the overvoltage signal, the third switch unit 132 is turned on to output the overvoltage signal through the third switch unit 132, and control the pre-charging module 120 to be in an off state.

The second switching unit 131 is configured to: when receiving the overvoltage signal, the second switching unit 131 is turned on to lock the control signal received by the relay control module 140 to the second control signal through the second switching unit 131 and discharge the electric energy stored in the pre-charge module 120.

In some embodiments, as shown in fig. 3, the priming module 120 includes: the precharge switching unit 121 and the precharge time unit 122 are connected to each other.

The over-voltage control module 130 is further connected to the pre-charge switch unit 121 and the pre-charge time unit 122, respectively.

The overpressure control module 130 is configured to: upon receiving the overvoltage signal, the precharge switching unit 121 is controlled to be in an off state while discharging the electric energy stored in the precharge time unit 122.

Specifically, the pre-charge switch unit 121 is disposed on a power supply line, and the switch ends of the relay 30 are connected in parallel to two ends of the pre-charge switch unit 121.

In some embodiments, as shown in fig. 3, the precharge switching unit 121 is connected to a power supply line.

In some embodiments, as shown in fig. 3, the third switching unit 132 is connected to the precharge switching unit 121, and the second switching unit 131 is connected to the precharge time unit 122. The endpoint pv_en1 is used to indicate the same circuit point.

In some embodiments, as shown in fig. 3, the relay control module 140 includes: the fourth switching unit 141, the diode D3, and the control signal input terminal pv_en.

The control terminal 1411 of the fourth switching unit 141 is connected to the control signal input terminal pv_en and the positive terminal of the diode D3, respectively, and the negative terminal of the diode D3 is connected to the overvoltage control module 130.

The connection terminal 1412 of the fourth switching unit 141 is connected to the coil terminal 31 of the relay 30.

The overpressure control module 130 is configured to: when receiving the overvoltage signal, the control signal received by the control signal input end pv_en is connected to the ground through the diode D3 and the second switch unit 131, so as to lock the control signal received by the fourth switch unit 141 to the second control signal, and further lock the relay to be in an off state, so as to avoid malfunction of the relay driven by the control signal received by the control signal input end pv_en.

In some embodiments, as shown in fig. 3, the cathode of the diode D3 is connected with the second switching unit 131 in the overvoltage control module 130.

In some embodiments, as shown in fig. 3, the switch end 32 of the relay 30 is disposed on a power supply line.

Fig. 4 is a schematic diagram of an overvoltage protection circuit according to an embodiment of the present application. The overvoltage protection circuit can be applied to the energy storage power supply shown in fig. 1, and protection of the circuit is realized.

In some embodiments, as shown in fig. 4, the second switching unit 131 includes: transistor Q1, resistor R1 and resistor R2.

The collector of the triode Q1 is respectively connected with the pre-charging module 120 and the relay control module 140; the base electrode of the triode Q1 is connected with one end of a resistor R1, and the other end of the resistor R1 is connected with a third switching unit 132; the base electrode of the triode Q1 is connected with one end of a resistor R2, and the other end of the resistor R2 is connected to the ground GND; the emitter of transistor Q1 is connected to ground GND.

In some embodiments, as shown in fig. 4, the collector of transistor Q1 is connected to the cathode of diode D3 in relay control module 140.

In some embodiments, as shown in fig. 4, the third switching unit 132 includes: transistor Q2 and resistor R3.

The base electrode of the triode Q2 is respectively connected with the overvoltage detection module 110 and one end of the resistor R3, and the other end of the resistor R3 is connected with a power supply circuit; the collector of the triode Q2 is respectively connected with the second switch unit 131 and the pre-charging module 120; the emitter of the triode Q2 is connected with a power supply circuit. In one embodiment, the input end PV+ of the power supply circuit is connected with the solar panel, and the output end of the power supply circuit is connected with the load.

In some embodiments, as shown in fig. 4, the precharge time unit 122 includes: a capacitor C1 and a resistor R4.

The first end of the resistor R4 is connected to the first output end A1 of the overvoltage control module 130 and the precharge switching unit 121, and the second end of the resistor R4 is connected to the second output end A2 of the overvoltage control module 130 and the first end of the capacitor C1, respectively, and the second end of the capacitor C1 is grounded.

The overpressure control module 130 is configured to: upon receiving the overvoltage signal, the precharge switching unit 121 is controlled to be in an off state while discharging the electric energy stored in the capacitor C1.

It can be understood that the capacitor C1 is a delay capacitor, which is used as a delay turn-off device, and by discharging the electric energy stored in the capacitor C1 when the input voltage of the power supply line is over-voltage, the input electric energy on the power supply line charges the capacitor C1 when the input voltage of the power supply line is switched from an over-voltage state to a normal power supply state, and drives the pre-charging switch unit to conduct for pre-charging. Therefore, when the input voltage is switched from an overvoltage state to normal power supply, the circuit is prevented from being damaged by the fact that the circuit cannot be precharged to generate surge heavy current.

In some embodiments, as shown in fig. 4, the precharge time unit 122 further includes: diode D1.

The positive electrode of the diode D1 is connected to the first end of the capacitor C1 and the second end of the resistor R4, and the negative electrode of the diode D1 is connected to the second output end A2 of the overvoltage control module 130.

In some embodiments, as shown in fig. 4, the collector of transistor Q1 forms a second output A2 of the overvoltage control module 130.

In some embodiments, as shown in fig. 4, the precharge time unit 122 further includes: diode D2.

The positive electrode of the diode D2 is connected to the first end of the capacitor C1, and the negative electrode of the diode D2 is connected to the power supply line.

The negative electrode of the diode D2 is connected with the power supply line, so that when the input voltage of the power supply line is zero (namely, the power supply line is powered off and is equivalent to the ground of the power supply line), the electric energy stored in the capacitor C1 can be discharged, when the power supply line is electrified again, the input electric energy on the power supply line charges the capacitor C1, and the pre-charging switch unit is driven to conduct for pre-charging, and when the capacitor C1 is fully charged, the pre-charging switch unit is driven to break so as to stop the pre-charging operation.

In some embodiments, as shown in fig. 4, the fourth switching unit 141 includes: transistor Q3, resistor R5 and resistor R6.

The base electrode of the triode Q3 is respectively connected with one end of a resistor R5 and one end of a resistor R6, the other end of the resistor R5 is respectively connected with the control signal input end PV_EN and the positive electrode of a diode D3, and the other end of the resistor R6 is connected to the ground; the collector of the triode Q3 is connected with the coil end 31 of the relay 30; the emitter of transistor Q3 is connected to ground GND.

In some embodiments, as shown in fig. 4, the overpressure detection unit 112 includes: a zener diode ZD1 and a resistor R7.

The negative electrode of the zener diode ZD1 is connected to the power supply line, the positive electrode of the zener diode ZD1 is connected to one end of the resistor R7, and the other end of the resistor R7 is connected to the first switching unit 111.

It should be noted that, the connection mode of the zener diode ZD1 in the overvoltage protection circuit is reverse connection, and the effect is that: when the voltage applied across the zener diode ZD1 exceeds a regulated value (i.e., a preset threshold), the zener diode ZD1 breaks down, and the current flowing through the zener diode ZD1 increases sharply, but the voltage across it remains unchanged and remains at the regulated value. When the voltage applied across the zener diode ZD1 does not exceed the regulated value, the dynamic resistance exhibited by it is very high, and the current passing through it is very small and negligible.

In some embodiments, as shown in fig. 4, the first switching unit 111 includes: transistor Q4, resistor R8 and resistor R9.

The base electrode of the triode Q4 is respectively connected with one end of a resistor R7 and one end of a resistor R8, and the other end of the resistor R8 is connected to the ground GND; the collector of the triode Q4 is connected with one end of a resistor R9, and the other end of the resistor R9 is connected with the base of the triode Q2 in the third switch unit 132; the emitter of transistor Q4 is connected to ground GND.

In some embodiments, as shown in fig. 4, the overvoltage protection circuit further includes: and a diode D4, wherein the diode D4 is disposed between the overvoltage detection module 110 and the pre-charging module 120, the anode of the diode D4 is connected with the collector of the triode Q2, and the cathode of the diode D4 is connected with the first end of the resistor R4.

In some embodiments, as shown in fig. 4, the precharge switching unit 121 includes: transistor Q5, resistor R10 and resistor R11.

The base electrode of the triode Q5 is connected with one end of a resistor R10, and the other end of the resistor R10 is connected with a first output end A1 of the overvoltage control module 130; the collector of the triode Q5 is connected with one end of a resistor R11, the other end of the resistor R11 is connected with the output end of a power supply circuit, and the emitter of the triode Q5 is connected with the power supply circuit.

In some embodiments, as shown in fig. 4, a first terminal of the pre-charge capacitor EC1 is connected to an output terminal of the power supply line, a second terminal of the pre-charge capacitor EC1 is connected to ground GND, and the output terminal of the power supply line is also connected to the load 20.

In some embodiments, the anode of the diode D2 is connected to the first terminal of the capacitor C1 and the second terminal of the resistor R4, respectively, and the cathode of the diode D2 is connected to the power supply line. Through being connected the negative pole of diode D2 with the power supply line, can be when the input voltage of power supply line is zero (i.e. when solar cell panel loses the power, the input of power supply line is equivalent to ground), the electric energy that stores in electric capacity C1 is connected to ground through diode D2 to the electric energy that stores electric capacity C1 is released, thereby when the power supply line is on again, the input electric energy on the power supply line charges for electric capacity C1, and drive prefill switch unit switches on and carries out the precharge action, after electric capacity C1 is full charge, drive prefill switch unit disconnection, with the stop precharge action.

As an example and not by way of limitation, the transistor may be a P-type transistor or an N-type transistor, and the specific transistor may be selected according to the voltage-withstanding level required by the practical application, which is not limited herein, so long as the same technical effect can be achieved.

By way of example and not limitation, the precharge capacitor EC1 described above is an electrolytic capacitor.

In some embodiments, the stored energy power supply further comprises: when the input voltage of the power supply line is smaller than or equal to a preset threshold value, the main control chip judges whether the voltage difference between the input voltage and the voltage at two ends of the precharge capacitor EC1 is smaller than or equal to a preset voltage difference or not; if the voltage difference is smaller than or equal to the preset voltage difference, generating a first control signal, and transmitting the first control signal to the relay control module; if the voltage difference is larger than the preset voltage difference, generating a second control signal, and transmitting the second control signal to the relay control module.

By way of example and not limitation, the preset voltage difference may be 5 volts (V) or 6 volts (V), and the specific preset voltage difference may be set according to the actual application scenario.

In order to fully explain the overvoltage protection circuit according to the embodiment of the present application, a specific implementation and an operation principle of the overvoltage protection circuit will be described in detail with reference to fig. 4.

(1) When the input voltage of the power supply line is greater than a preset threshold value, the zener diode ZD1 is broken down, voltage division is performed through the resistor R7 and the resistor R8, and when the voltage at two ends of the resistor R8 is greater than the base voltage of the triode Q4, the triode Q4 is conducted. The resistor R7 and the resistor R8 are used for voltage division, so that an overvoltage protection trigger point can be accurately adjusted, and meanwhile, the resistor R7 can limit the base current of the triode Q4 after the triode Q4 is conducted. The resistor R8 is a BE electrode resistor of the triode Q4, the BE electrode resistor is a resistor between a base electrode and an emitter electrode in the triode Q4, and when the zener diode ZD1 is not broken down, the base electrode of the triode Q4 can BE pulled down to GND, so that misconduction of the triode Q4 is avoided.

(2) After the triode Q4 is conducted, the triode Q2 is conducted, R3 is a BE electrode resistor of the triode Q2, when the triode Q4 is not conducted, the base electrode of the triode Q2 is pulled up to an input voltage, misconduction of the triode Q2 is avoided, after the triode Q4 is conducted, the voltage at two ends of the resistor R3 is equal to the voltage difference between the emitter electrode and the base electrode of the triode Q2, R9 is a base electrode current limiting resistor of the triode Q2, and after the triode Q4 is conducted, the base electrode current of the triode Q2 can BE limited. The resistor R2 is a BE electrode resistor of the triode Q1, the resistor R1 is a base electrode current limiting resistor of the triode Q1, after the triode Q2 is conducted, the voltage at two ends of the resistor R2 is equal to the voltage difference between an emitter electrode and a base electrode of the triode Q1, the resistor R1 limits the current flowing through the base electrode of the triode Q1 so as to drive the triode Q1 to BE conducted, and the triode Q1 is connected with the triode Q3 due to the fact that the triode Q1 is conducted to BE grounded and then the base electrode of the triode Q3 is pulled down to GND, and when the triode Q2 is not conducted, the triode Q1 is in a disconnected state.

(3) After the triode Q2 is conducted, the triode Q1 is conducted, a control signal received by the control signal input end is forced to be pulled down through the diode D3 and the triode Q1, namely, the triode Q3 is forced to be cut off no matter whether the control signal sent by the main control chip is a first control signal or a second control signal, so that the relay is in a cut-off state, the input voltage cannot reach a load, and further the rear-stage circuit is protected from being damaged by overhigh voltage.

(4) After the triode Q2 is conducted, the input voltage passes through the triode Q2 and the diode D4, one end of the resistor R10 is boosted to be the input voltage, so that the triode Q5 is cut off, namely, when the input voltage is larger than a preset threshold value, the triode Q5 is cut off, and the charging of the pre-charge capacitor EC1 is stopped, so that a later-stage circuit is protected from being damaged by the excessively high voltage.

(5) Diode D1 is added to connect to pv_en1 and diode D2 is connected to the power supply line in the precharge time unit, respectively. Thus, when triggering overvoltage protection, triode Q2 switches on, and input voltage passes through triode Q2, resistance R1 drive triode Q1 switches on, and PV_EN1 ground connection this moment, and the return circuit of circuit this moment is: the input voltage passes through the transistor Q2, the diode D4, the resistor R4, the diode D1 and the transistors Q1 to GND, so that the capacitor C1 discharges through the diode D1 and the transistors Q1 to GND, and the capacitor C1 is always kept in a zero state (the voltage drop across the capacitor C1 is close to 0V). When the input voltage is zero, namely the power supply line is powered off, which is equivalent to the grounding of the power supply line, the capacitor C1 discharges through the diode D2, so that the voltage at two ends of the capacitor C1 is zero when the power supply line is electrified again or the input voltage is converted from an overvoltage state to a normal state, so that the input electric energy on the power supply line charges the capacitor C1, the triode Q5 is driven to be conducted for the precharge action, and after the capacitor C1 is fully charged, the triode Q5 is driven to be disconnected for stopping the precharge action. The condition for the transistor Q5 to be turned off is: the conduction voltage drop of transistor Q2 plus the voltage drop of diode D4 is less than the base voltage drop of transistor Q5 plus the voltage across resistor R10.

(6) When the input voltage of the power supply line is smaller than or equal to a preset threshold value and the input voltage is larger than zero, or when the input voltage of the power supply line is recovered to a normal state from an overvoltage state, the triode Q2 is cut off, the triode Q1 is cut off, the triode Q5 is conducted, the input voltage charges the capacitor C1 through the base electrode of the triode Q5, the resistor R10 and the resistor R4, and meanwhile, the input voltage charges the pre-charge capacitor EC1 through the collector electrode of the triode Q5 and the resistor R11, so that the pre-charge effect of the overvoltage protection circuit when the input voltage is over-voltage is achieved, and the function of the overvoltage protection circuit rapidly recovering the pre-charge when the input voltage is released in the overvoltage state is achieved.

It should be noted that the above-mentioned "first" and "second" are used for illustration only and are not intended to limit the importance of the terms modified thereafter or the specific implementation form. Those skilled in the art may choose to use the same or different implementations as the actual situation requires.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; the technical features of the above embodiments or in the different embodiments may also be combined within the idea of the invention, the steps may be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims

1. The overvoltage protection circuit is characterized by being arranged on a power supply line, a relay is arranged on the power supply line, and the overvoltage protection circuit comprises an overvoltage detection module, a pre-charging module, an overvoltage control module and a relay control module;

The overvoltage detection module is respectively connected with the power supply circuit and the overvoltage control module, the overvoltage control module is also connected with the pre-charging module and the relay control module, and the relay control module is also connected with the relay;

the relay control module is configured to: when a first control signal is received, the relay is controlled to be closed; and when receiving a second control signal, controlling the relay to be disconnected;

The overvoltage detection module is configured to: when the input voltage on the power supply line is greater than a preset threshold value, outputting an overvoltage signal;

the overvoltage control module is configured to: when the overvoltage signal is received, the pre-charging module is controlled to be in a disconnected state, and the control signal received by the relay control module is locked in the second control signal;

The overvoltage detection module includes: a first switching unit and an overvoltage detection unit;

One end of the overvoltage detection unit is connected with the power supply circuit, the other end of the overvoltage detection unit is connected with the first switch unit, and the first switch unit is also connected with the pre-charging module and the relay control module respectively;

The overvoltage detection unit is configured to: outputting an overvoltage detection signal when the input voltage on the power supply line is greater than the preset threshold value;

the first switching unit is configured to: when the overvoltage detection signal is received, the first switch unit is conducted so as to output the overvoltage signal through the first switch unit;

The overvoltage control module is further configured to: when the overvoltage signal is received, the pre-charging module is controlled to be in a disconnected state, and meanwhile, the electric energy stored in the pre-charging module is discharged;

The overvoltage control module includes: a second switching unit and a third switching unit;

The second switch unit is respectively connected with the third switch unit, the pre-charging module and the relay control module, and the third switch unit is respectively connected with the overvoltage detection module and the pre-charging module;

the third switching unit is configured to: when the overvoltage signal is received, the third switch unit is conducted so as to output the overvoltage signal through the third switch unit, and the pre-charging module is controlled to be in an off state;

The second switching unit is configured to: when the overvoltage signal is received, the second switch unit is conducted, so that the control signal received by the relay control module is locked on the second control signal through the second switch unit, and the electric energy stored in the pre-charging module is discharged.

2. The overvoltage protection circuit of claim 1, wherein the second switching unit comprises: transistor Q1, resistor R1 and resistor R2; the third switching unit includes: transistor Q2 and resistor R3;

the collector electrode of the triode Q1 is respectively connected with the pre-charging module and the relay control module;

the base electrode of the triode Q1 is connected with one end of the resistor R1, and the other end of the resistor R1 is connected with the collector electrode of the triode Q2;

the base electrode of the triode Q1 is connected with one end of the resistor R2, and the other end of the resistor R2 is connected to the ground;

the emitter of the triode Q1 is connected to the ground;

The base electrode of the triode Q2 is respectively connected with the overvoltage detection module and one end of the resistor R3, and the other end of the resistor R3 is connected with the power supply circuit;

the collector electrode of the triode Q2 is connected with the pre-charging module;

and the emitter of the triode Q2 is connected with the power supply circuit.

3. The overvoltage protection circuit of claim 1, wherein the pre-charge module comprises a pre-charge switch unit and a pre-charge time unit that are connected to each other, and the overvoltage control module is further connected to the pre-charge switch unit and the pre-charge time unit, respectively;

The overvoltage control module is configured to: when the overvoltage signal is received, the pre-charging switch unit is controlled to be in an off state, and meanwhile, the electric energy stored in the pre-charging time unit is discharged.

4. The overvoltage protection circuit of claim 3, wherein the precharge time unit comprises: a capacitor C1 and a resistor R4;

The first end of the resistor R4 is respectively connected with the first output end of the overvoltage control module and the pre-charging switch unit, the second end of the resistor R4 is respectively connected with the second output end of the overvoltage control module and the first end of the capacitor C1, and the second end of the capacitor C1 is grounded;

The overvoltage control module is configured to: when the overvoltage signal is received, the pre-charging switch unit is controlled to be in an off state, and meanwhile, the electric energy stored in the capacitor C1 is discharged.

5. The overvoltage protection circuit of claim 4, wherein the precharge time unit further comprises: a diode D1;

the positive pole of diode D1 is connected with the first end of electric capacity C1 and the second end of resistance R4 respectively, the negative pole of diode D1 is connected with the second output of overvoltage control module.

6. The overvoltage protection circuit of claim 1, wherein the relay control module comprises: triode Q3, resistance R5, resistance R6, diode D3 and control signal input end;

the base electrode of the triode Q3 is respectively connected with one end of the resistor R5 and one end of the resistor R6, the other end of the resistor R5 is respectively connected with the control signal input end and the positive electrode of the diode D3, and the other end of the resistor R6 is connected to the ground;

the cathode of the diode D3 is connected with the overvoltage control module;

The collector electrode of the triode Q3 is connected with the coil end of the relay; the emitter of the triode Q3 is connected to the ground;

The overvoltage control module is configured to: when the overvoltage signal is received, the control signal received by the control signal input end is connected to the ground through the diode D3, so that the control signal received by the triode Q3 is locked on the second control signal.

7. Overvoltage protection circuit according to any one of claims 1 to 6, characterized in that the input of the supply line is connected to a solar panel.

8. An energy storage power supply, comprising: an overvoltage protection circuit according to any one of claims 1 to 7.