A reverse connection protection circuit and a reverse connection protection method

Abstract

The present invention provides an anti-reverse polarity protection circuit and an anti-reverse polarity protection method, comprising a main circuit, a detection circuit and a drive control circuit; the main circuit comprises a photovoltaic panel, a positive main circuit and a negative main circuit, and the positive main circuit and the negative main circuit each comprise at least one electrical control device; the output end of the detection circuit is electrically connected to the input end of the drive control circuit, and the detection circuit is electrically connected to the main circuit for detecting whether the photovoltaic panel is reversely connected; the drive control circuit is electrically connected to the main circuit for controlling the electrical control device to softly shut down after detecting that the photovoltaic panel is reversely connected, thereby ensuring that the reverse connection of the photovoltaic panel can be detected, and actively responding after the photovoltaic panel is reversely connected to protect the circuit.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, and in particular to an anti-reverse connection protection circuit and an anti-reverse connection protection method. Background Art

[0002] In a photovoltaic power supply system, photovoltaic panels need to be connected to the DC bus. However, the positive and negative terminals of the photovoltaic panels may be reversed. If reversed, it will cause serious damage to the photovoltaic inverter or other components in the circuit. Therefore, the interface between the photovoltaic panel and the photovoltaic inverter must be reversed to detect the connection and respond when the photovoltaic panel is reversed.

[0003] In the prior art, the anti-reverse polarity protection circuit generally detects the voltage of the photovoltaic panel through a voltage sensor to detect whether the photovoltaic panel is reversely connected. This solution is relatively expensive and can only detect the reverse polarity anomaly, but cannot directly handle the reverse polarity anomaly. In other technical solutions, the DC end reverse polarity protection technology is implemented through a diode. Within a certain voltage and current range, the unidirectional conduction characteristic of the diode can achieve a DC reverse polarity protection function of forward conduction and reverse cutoff. However, in this solution, the forward conduction voltage drop of the diode is large, which will further lead to increased losses when the photovoltaic inverter is in a high current working condition, damaging components in the circuit. Summary of the Invention

[0004] The problem solved by the present invention is how to actively cut off the circuit when a photovoltaic panel is reversely connected.

[0005] In order to solve the above problems, the present invention provides an anti-reverse connection protection circuit, comprising a main circuit, a detection circuit and a drive control circuit;

[0006] The main circuit includes a photovoltaic panel, a positive main circuit and a negative main circuit, and each of the positive main circuit and the negative main circuit includes at least one electric control device;

[0007] The output end of the detection circuit is electrically connected to the input end of the drive control circuit, and the detection circuit is electrically connected to the main circuit, for detecting whether the photovoltaic panel is reversely connected;

[0008] The drive control circuit is electrically connected to the main circuit and is used to control the electric control device to softly shut down after detecting that the photovoltaic panel is reversely connected.

[0009] Optionally, the detection circuit includes a differential sampling circuit, and the differential sampling circuit includes a positive sampling resistor, a negative sampling resistor, a positive current limiting resistor, and a negative current limiting resistor;

[0010] One end of the positive sampling resistor is electrically connected to the positive main circuit, and the other end of the positive sampling resistor is electrically connected to the differential sampling circuit through the positive current limiting resistor; one end of the negative sampling resistor is electrically connected to the negative main circuit, and the other end of the negative sampling resistor is electrically connected to the negative main circuit through the negative current limiting resistor.

[0011] Optionally, the detection circuit also includes a hysteresis comparison circuit and an AND gate circuit, the input end of the hysteresis comparison circuit is electrically connected to the output end of the differential sampling circuit, the output end of the hysteresis comparison circuit is electrically connected to the input end of the AND gate circuit, and the AND gate circuit is used to logically compare the output signal of the hysteresis comparison circuit with a reference circuit.

[0012] Optionally, the detection circuit also includes an auxiliary power supply and a reference circuit, the auxiliary power supply is respectively connected to the drive control circuit, the differential sampling circuit, the hysteresis comparison circuit, the AND gate circuit and the reference circuit, the reference circuit is used to generate the reference signal, and the reference signal is used to compare with the output signal of the hysteresis comparison circuit.

[0013] Optionally, the main circuit further includes a photovoltaic inverter, a second relay and a third relay;

[0014] The output end of the drive control circuit is connected to the electromagnetic parts of the second relay and the third relay;

[0015] The contact portion of the second relay is arranged in the positive main circuit, and the contact portion of the second relay is electrically connected to the positive output terminal of the photovoltaic panel and the positive input terminal of the photovoltaic inverter;

[0016] The contact portion of the third relay is arranged in the negative main circuit, and the contact portion of the third relay is electrically connected to the negative output terminal of the photovoltaic panel and the negative input terminal of the photovoltaic inverter.

[0017] Optionally, the main circuit further includes a first relay and a switch tube;

[0018] Two ends of the contact portion of the first relay are electrically connected to two ends of the switch tube respectively, and the electromagnetic portion of the first relay is electrically connected to the output end of the drive control circuit;

[0019] The switch tube is arranged in the positive main circuit, and the switch tube is electrically connected to the positive output terminal of the photovoltaic panel and the positive input terminal of the photovoltaic inverter.

[0020] Optionally, if the sampled voltage is less than a first voltage threshold, controlling the detection circuit to generate a logic control signal includes:

[0021] When the sampled voltage is less than the first voltage threshold, a high level voltage is output through the hysteresis comparison circuit;

[0022] An AND gate circuit performs a logic comparison on the high-level voltage and then outputs an isolated and amplified high-level signal, wherein the logic control signal includes the high-level signal.

[0023] On the other hand, the present invention also provides an anti-reverse connection protection method, based on the anti-reverse connection protection circuit as described above, the anti-reverse connection protection method includes:

[0024] Acquire a sampled voltage of the main circuit, wherein the sampled voltage includes a positive electrode sampled voltage and a negative electrode sampled voltage;

[0025] If the sampled voltage is greater than a first voltage threshold, the detection circuit is controlled to generate a reverse connection protection signal;

[0026] Controlling the drive control circuit to output a first control signal and a second control signal through the reverse connection protection signal;

[0027] turning off the first relay, the second relay, and the third relay based on the first control signal;

[0028] The switch tube is turned off based on the second control signal.

[0029] Optionally, after obtaining the sampled voltage of the main circuit, the method further includes:

[0030] If the sampled voltage is less than the first voltage threshold, the detection circuit is controlled to generate a logic control signal;

[0031] Controlling the drive control circuit to control the second relay and the third relay to be attracted according to the logic control signal;

[0032] After the second relay and the third relay are energized, controlling the drive control circuit to turn on the switch tube;

[0033] After a preset period of time, the drive controller is controlled to control the first relay to be energized and the switch tube to be turned off.

[0034] Optionally, if the sampled voltage is greater than a first voltage threshold, controlling the detection circuit to generate a reverse connection protection signal includes:

[0035] When the sampling voltage is greater than the first voltage threshold, a low-level voltage is output through a hysteresis comparison circuit;

[0036] An AND gate circuit performs a logic comparison on the low-level voltage and then outputs an isolated and amplified low-level signal, wherein the reverse connection protection signal includes the low-level signal.

[0037] In a third aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon; when the computer program is executed by a processor, the anti-reverse connection protection method as described above is implemented.

[0038] Compared with the existing technology, the present invention detects the voltage of the positive main circuit and the negative main circuit through a detection circuit, thereby obtaining the photovoltaic panel connection result based on the detection result. When the detection result is abnormal, it indicates that the photovoltaic panel is reversely connected, and the electrical control devices on the positive main circuit and the negative main circuit are driven by the driving circuit, thereby realizing soft shutdown of the main circuit when the photovoltaic panel is reversely connected, thereby protecting the safe and reliable operation of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic block diagram of an anti-reverse connection protection circuit according to an embodiment of the present invention;

[0040] Figure 2 A circuit diagram of an anti-reverse connection protection circuit according to an embodiment of the present invention;

[0041] Figure 3 Schematic diagram of the flow of the anti-reverse connection protection method according to an embodiment of the present invention;

[0042] Figure 4 1 is a flow chart of the anti-reverse connection protection circuit after step S100 according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein. Instead, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0044] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0045] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc. mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0046] It should be noted that the modifications of "one" and "multiple" mentioned in the present invention are illustrative rather than restrictive. Those skilled in the art should understand that unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0047] like Figure 1 As shown, an embodiment of the present invention provides a reverse connection protection circuit, including a main circuit, a detection circuit and a drive control circuit;

[0048] The main circuit includes a photovoltaic panel, a positive main circuit and a negative main circuit, and each of the positive main circuit and the negative main circuit includes at least one electric control device;

[0049] The output end of the detection circuit is electrically connected to the input end of the drive control circuit, and the detection circuit is electrically connected to the main circuit, for detecting whether the photovoltaic panel is reversely connected;

[0050] The drive control circuit is electrically connected to the main circuit and is used to control the electric control device to softly shut down after detecting that the photovoltaic panel is reversely connected.

[0051] For the sake of clarity, in the present invention, the main circuit refers to a circuit composed of photovoltaic panels and other electric energy conversion devices.

[0052] In one embodiment, the main circuit includes a positive main circuit and a negative main circuit, wherein the positive main circuit is electrically connected to the positive output terminal of the photovoltaic panel, and the negative main circuit is electrically connected to the negative output terminal of the photovoltaic panel, and the positive main circuit, the photovoltaic panel, the negative main circuit and other devices in the main circuit form a pathway.

[0053] In one embodiment, a detection circuit is used to detect whether a photovoltaic panel is reversely connected. If reverse connection is detected, the detection circuit generates a corresponding detection signal for transmission to a drive control circuit. The drive control circuit has an input electrically connected to the detection circuit and an output drive connected to the main circuit. The drive control circuit receives the detection signal from the detection circuit and processes the detection signal to generate a drive control signal to drive electrical control devices in the positive and negative main circuits. This signal is used to promptly disconnect the main circuits when the photovoltaic panel is reversely connected, thereby protecting the photovoltaic power generation equipment.

[0054] In another embodiment, after the electrical control device and the detection circuit are powered normally, if the detection circuit detects that the photovoltaic panel is normally connected, the detection circuit generates a corresponding detection signal and transmits it to the drive control circuit, which then drives the electrical control device in the main circuit normally to achieve normal opening of the circuit.

[0055] Preferably, the electrical control device includes a mechanical switch such as a relay or a contactor that is controlled by an electrical signal as input.

[0056] Optionally, the detection circuit includes a differential sampling circuit, and the differential sampling circuit includes a positive sampling resistor, a negative sampling resistor, a positive current limiting resistor, and a negative current limiting resistor;

[0057] One end of the positive sampling resistor is electrically connected to the positive main circuit, and the other end of the positive sampling resistor is electrically connected to the differential sampling circuit through the positive current limiting resistor; one end of the negative sampling resistor is electrically connected to the negative main circuit, and the other end of the negative sampling resistor is electrically connected to the negative main circuit through the negative current limiting resistor.

[0058] Specifically, due to the advantages of differential sampling circuits, such as high sampling accuracy, a wide range of applications, and the ability to achieve isolation, amplification, and interference resistance, the detection circuit samples voltage signals through a differential sampling circuit. A positive sampling resistor is provided in the positive main circuit, and a negative sampling resistor is provided in the negative main circuit. These resistors are used to receive the stepped-down positive and negative voltages of the main circuits and input them into the inverting and non-inverting inputs of the differential sampling circuits through current-limiting resistors, thereby sampling the positive and negative voltages of the main circuits.

[0059] For clarity, in the figure, PV+ represents the positive output voltage of the photovoltaic panel, and PV- represents the negative output voltage of the photovoltaic panel.

[0060] In one embodiment, if Figure 2As shown, the negative sampling resistor R2 connected to the negative main circuit receives the negative voltage V_PV1- after the main circuit is stepped down. After current limiting by the negative current limiting resistor R3, the voltage is input to the inverting input terminal of the differential sampling circuit. The positive sampling resistor R1 connected to the positive main circuit receives the positive voltage V_PV1+ after the main circuit is stepped down. After current limiting by the negative current limiting resistor R4, the voltage is input to the positive input terminal of the differential sampling circuit. This realizes the sampling of the positive and negative voltages of the main circuit, and the differential sampling circuit outputs the voltage V13.

[0061] Optionally, the detection circuit also includes a hysteresis comparison circuit and an AND gate circuit, the input end of the hysteresis comparison circuit is electrically connected to the output end of the differential sampling circuit, the output end of the hysteresis comparison circuit is electrically connected to the input end of the AND gate circuit, and the AND gate circuit is used to logically compare the output signal of the hysteresis comparison circuit with a reference circuit.

[0062] Specifically, the detection circuit also includes a hysteresis comparison circuit and an AND gate circuit, wherein the hysteresis comparison circuit includes comparing the output voltage from the differential sampling circuit to determine whether the output voltage is normal, and then generating a high level or a low level based on the judgment result, and passing it to the AND gate circuit for logical comparison. After the logical comparison, the comparison result is processed into an isolated and amplified high level / low level signal to provide a logical control signal for the drive control circuit.

[0063] The hysteresis comparator circuit is a comparator with hysteresis loop transmission characteristics. It has two threshold voltages. When the input changes in one direction, the output only jumps once, and it has strong anti-interference ability.

[0064] like Figure 2 As shown, in one embodiment, a hysteresis comparator circuit compares the input voltage V21 of the voltage divider circuit with the voltage V22 of the output voltage V13 of the differential sampling circuit after current limiting by the current limiting resistor, and determines whether the voltages are normal. A high level or a low level is output based on the determination result, and the output level V32 is transmitted to the AND gate circuit. The AND gate circuit then performs a logic comparison and outputs an isolated and amplified level signal to provide a logic control signal IO_1 for the drive control circuit.

[0065] Optionally, the detection circuit also includes an auxiliary power supply and a reference circuit, the auxiliary power supply is respectively connected to the drive control circuit, the differential sampling circuit, the hysteresis comparison circuit, the AND gate circuit and the reference circuit, the reference circuit is used to generate the reference signal, and the reference signal is used to compare with the output signal of the hysteresis comparison circuit.

[0066] Among them, the input of the auxiliary power supply is industrial frequency alternating current.

[0067] In one embodiment, after the AC side of the photovoltaic inverter is powered on, the auxiliary power supply is used to power the detection circuit and other electrical control components in the main circuit. The reference circuit is used to provide a reference signal V31 to the AND gate circuit in the detection circuit for logical comparison with the output level V32 from the hysteresis comparator circuit.

[0068] Optionally, the main circuit further includes a photovoltaic inverter, a second relay and a third relay;

[0069] The output end of the drive control circuit is connected to the electromagnetic parts of the second relay and the third relay;

[0070] The contact portion of the second relay is arranged in the positive main circuit, and the contact portion of the second relay is electrically connected to the positive output terminal of the photovoltaic panel and the positive input terminal of the photovoltaic inverter;

[0071] The contact portion of the third relay is arranged in the negative main circuit, and the contact portion of the third relay is electrically connected to the negative output terminal of the photovoltaic panel and the negative input terminal of the photovoltaic inverter.

[0072] Specifically, the main circuit also includes a photovoltaic inverter and multiple relays. The positive and negative input terminals of the photovoltaic inverter are electrically connected to the positive and negative output terminals of the photovoltaic panel, forming a circuit to achieve the photovoltaic power generation function. The positive main circuit also includes at least one relay, designated as a second relay; the negative main circuit also includes at least one relay, designated as a third relay. The opening and closing of the second and third relays are controlled by a drive signal from the drive control circuit. When the second relay is turned off, the positive main circuit is also disconnected; when the third relay is turned off, the negative main circuit is also disconnected. Thus, the detection circuit detects whether the photovoltaic panel is reversely connected and transmits the detection signal to the drive control circuit, which generates a drive signal to achieve the photovoltaic panel's anti-reverse connection function.

[0073] A relay is a remotely controlled or automatically controlled electromagnetic device that changes the circuit condition to activate and switch other devices (such as converters, circuit breakers) in the same circuit or different circuits to operate.

[0074] In one embodiment, if Figure 2 As shown, the contact parts of the second relay K2 and the third relay K3 are respectively arranged in the positive main circuit and the negative main circuit, and the electromagnetic parts are respectively electrically connected to the output ends of the drive control circuit, and are used to be opened or closed by the control signal IO_PV1 of the drive control circuit.

[0075] Optionally, the main circuit further includes a first relay and a switch tube;

[0076] Two ends of the contact portion of the first relay are electrically connected to two ends of the switch tube respectively, and the electromagnetic portion of the first relay is electrically connected to the output end of the drive control circuit;

[0077] The switch tube is arranged in the positive main circuit, and the switch tube is electrically connected to the positive output terminal of the photovoltaic panel and the positive input terminal of the photovoltaic inverter.

[0078] Optionally, if the sampled voltage is less than a first voltage threshold, controlling the detection circuit to generate a logic control signal includes:

[0079] When the sampled voltage is less than the first voltage threshold, a high level voltage is output through the hysteresis comparison circuit;

[0080] An AND gate circuit performs a logic comparison on the high-level voltage and then outputs an isolated and amplified high-level signal, wherein the logic control signal includes the high-level signal.

[0081] Preferably, the switch tube includes an IGBT, a MOSFET, a BJT or other semiconductor switching devices.

[0082] Specifically, the first relay is arranged in the positive main circuit in the main circuit, and is electrically connected to the switching tube. When the first relay is in different on and off states, the switching tube is also isolated from the positive main circuit or connected to the positive main circuit by the first relay.

[0083] The two ends of the contact part of the first relay are electrically connected to the two ends of the switching tube respectively. When the contact part of the first relay is closed, the switching tube is isolated from the positive main circuit to turn off the switching tube. When the contact part of the first relay is disconnected, the switching tube is connected from the positive main circuit to turn on the switching tube. The output end of the drive control circuit is connected to the electromagnetic part of the first relay for driving the first relay on and off.

[0084] In one embodiment, if Figure 2As shown, the drive controller is connected to the electromagnetic component of the first relay K1. The contact of the first relay K1 is connected in parallel with the switching transistor V1. The first relay K1 and the switching transistor V1 are arranged in the positive main circuit. After the detection circuit determines that the photovoltaic panel is reversely connected, it outputs an isolated and amplified low-level signal IO_1 to the drive control circuit. The drive control circuit is at a low level and outputs a control signal IO_PV1 to the second and third relays K2 and K3, eliminating the pressure difference between the electromagnetic components of the second and third relays K2 and K3, thereby disconnecting the second and third relays K2 and K3. The control signal Relay_PV1 is also output to the first relay K1, eliminating the pressure difference between the electromagnetic components of the first relay K1, thereby disconnecting the first relay K1. In this reverse connection state, to further ensure that the DC input of the inverter is completely disconnected and prevent the second and third relays K2 and K3 from sticking or other faults that may cause the relays to abnormally engage, the drive control circuit simultaneously outputs a control signal Vge to shut off the switching transistor V1, further enhancing the protection function of the photovoltaic inverter when the DC input is reversely connected.

[0085] In another embodiment, when the photovoltaic panel is connected to the positive voltage, the detection circuit outputs an isolated and amplified high-level signal IO_1 to the drive control circuit. The drive control circuit is at a high level, and the drive control circuit first outputs a signal IO_PV1 to close the second and third relays K2 and K3. It then outputs a drive control signal Vge to turn on the switch V1, thereby implementing a soft-start process before the photovoltaic inverter is properly connected. After a preset period of time, i.e., after the photovoltaic inverter is operating normally, the drive control circuit outputs a control signal Relay_PV1 to close the first relay K1. When the first relay K1 is fully closed, the switch V1 is turned off, thereby providing a safe, stable, and efficient input voltage for the photovoltaic inverter.

[0086] When the photovoltaic inverter is shut down or the photovoltaic DC side input terminal is shut down, in order to ensure that the photovoltaic inverter is soft shut down, the drive control circuit first outputs the control signal Vge to control the switch tube V1 to turn on. After the switch tube V1 is turned on, the output control signal Relay_PV1 controls the first relay K1 to disconnect the contact part, and then the output control signal IO_PV1 disconnects the contacts of the second relay K2 and the third relay K3, thereby achieving soft shutdown of the DC input terminal of the photovoltaic inverter.

[0087] On the other hand, Figure 3 As shown, an embodiment of the present invention provides an anti-reverse connection protection method. Based on the anti-reverse connection protection circuit described above, the anti-reverse connection protection method includes:

[0088] Step S100, obtaining a sampled voltage of the main circuit, wherein the sampled voltage includes a positive sampled voltage and a negative sampled voltage;

[0089] Step S200: If the sampled voltage is greater than a first voltage threshold, the detection circuit is controlled to generate a reverse connection protection signal;

[0090] Step S300, controlling the drive control circuit to output a first control signal and a second control signal through the reverse connection protection signal;

[0091] Step S400: turning off the first relay, the second relay, and the third relay based on the first control signal;

[0092] Step S500: turning off the switch tube based on the second control signal.

[0093] Preferably, the first voltage threshold is 2.5V, and the first voltage threshold is determined by electronic components of the hysteresis comparison circuit.

[0094] In one embodiment, if Figure 2 As shown, the voltages of the positive main circuit and the negative main circuit are collected through the voltage-dividing resistor and the current-limiting resistor between the differential sampling circuit and the main circuit, and are input to the non-inverting input terminal and the inverting input terminal of the differential sampling circuit. If the input voltage of the differential sampling circuit is greater than 2.5V, it means that the photovoltaic panel is reversely connected. The hysteresis comparator circuit outputs a low level after comparison, and the AND gate circuit performs a logic comparison on the reference circuit and the high level and outputs an isolated and amplified low level signal to provide a logic control signal for the drive control circuit. The logic control signal includes a first control signal and a second control signal.

[0095] In this embodiment, the first control signal is the IO_PV1 signal and the Relay_PV1 signal, which are used to control the relays in the circuit to disconnect the relays. When the first relay K1 is disconnected, in order to prevent the second relay K2 and the third relay K3 from sticking or other faults that may cause the relays to be abnormally attracted, the second control signal, i.e., the Vge signal, is used to turn off the switch tube V1, thereby further enhancing the protection function of the photovoltaic inverter when the DC input terminal is in a reverse connection state.

[0096] Alternatively, as Figure 4 As shown, after obtaining the sampled voltage of the main circuit, the method further includes:

[0097] Step S110, if the sampled voltage is less than the first voltage threshold, controlling the detection circuit to generate a logic control signal;

[0098] Step S120, controlling the drive control circuit to control the second relay and the third relay to be energized according to the logic control signal;

[0099] Step S130, after the second relay and the third relay are energized, controlling the drive control circuit to turn on the switch tube;

[0100] Step S140: After a preset period of time, control the drive controller to control the first relay to be energized and turn off the switch tube.

[0101] In one embodiment, if Figure 2 As shown, when the sampled voltage is less than 2.5V, that is, when the output voltage of the differential sampling circuit is less than 2.5V, the hysteresis comparator circuit compares and outputs a high-level output voltage V32. This is then compared with the AND gate circuit and then outputs an isolated and amplified high-level signal, providing a logic control signal IO_1 to the drive control circuit. The drive control circuit generates a Relay_PV1 signal to control the first relay K1 to energize. When the first relay K1 is fully energized, it generates a Vge signal to control the switch V1 to turn off, thereby providing a safe, stable, and efficient input voltage for the photovoltaic inverter. When the photovoltaic inverter is shut down or its DC input is shut down, the drive control circuit generates a control signal Vge to turn on the switch V1 to achieve a soft shutdown of the photovoltaic inverter. It then outputs a control signal Relay_PV1 to control the first relay K1 to disconnect. The output control signal IO_PV1 then controls the second and third relays K2 and K3 to disconnect, thereby achieving a soft shutdown of the photovoltaic inverter's DC input.

[0102] Optionally, if the sampled voltage is greater than a first voltage threshold, controlling the detection circuit to generate a reverse connection protection signal includes:

[0103] When the sampling voltage is greater than the first voltage threshold, a low-level voltage is output through a hysteresis comparison circuit;

[0104] An AND gate circuit performs a logic comparison on the low-level voltage and then outputs an isolated and amplified low-level signal, wherein the reverse connection protection signal includes the low-level signal.

[0105] Another embodiment of the present invention provides an electronic device, comprising a memory and a processor; the memory is used to store a computer program; the processor is used to implement the above-mentioned anti-reverse connection protection method when executing the computer program.

[0106] Yet another embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the above-mentioned anti-reverse connection protection method is implemented.

[0107] An electronic device that can serve as a server or client of the present invention will now be described, which is an example of a hardware device that can be applied to various aspects of the present invention. Electronic devices are intended to represent various forms of digital electronic computer devices, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0108] An electronic device includes a computing unit that can perform various appropriate actions and processes based on a computer program stored in a read-only memory (ROM) or a computer program loaded from a storage unit into a random access memory (RAM). Various programs and data required for device operation can also be stored in the RAM. The computing unit, ROM, and RAM are connected to each other via a bus. An input / output (I / O) interface is also connected to the bus.

[0109] A computer system may include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The client and server relationship arises through computer programs running on the respective computers and having a client-server relationship to each other.

[0110] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM). In this application, the units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiments of the present invention. In addition, the functional units in the various embodiments of the present invention can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into a single unit. The above-mentioned integrated units can be implemented in the form of hardware or software functional units.

[0111] Although the present disclosure is disclosed as above, the protection scope of the present disclosure is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present disclosure, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A reverse connection protection circuit, characterized in that: Including main circuit, detection circuit and drive control circuit; The main circuit includes a photovoltaic panel, a positive main circuit and a negative main circuit, and each of the positive main circuit and the negative main circuit includes at least one electric control device; The detection circuit includes a differential sampling circuit, a positive sampling resistor, a negative sampling resistor, a positive current limiting resistor and a negative current limiting resistor; One end of the positive sampling resistor is electrically connected to the positive main circuit, and the other end of the positive sampling resistor is electrically connected to the differential sampling circuit through the positive current limiting resistor; one end of the negative sampling resistor is electrically connected to the negative main circuit, and the other end of the negative sampling resistor is electrically connected to the negative main circuit through the negative current limiting resistor; The detection circuit further includes a hysteresis comparison circuit and an AND gate circuit, wherein the input end of the hysteresis comparison circuit is electrically connected to the output end of the differential sampling circuit, the output end of the hysteresis comparison circuit is electrically connected to the input end of the AND gate circuit, and the AND gate circuit is used to perform a logical comparison between the output signal of the hysteresis comparison circuit and a reference signal; The output end of the detection circuit is electrically connected to the input end of the drive control circuit, and the detection circuit is electrically connected to the main circuit, for detecting whether the photovoltaic panel is reversely connected; The drive control circuit is electrically connected to the main circuit and is used to control the electric control device to softly shut down after detecting that the photovoltaic panel is reversely connected.

2. The anti-reverse connection protection circuit according to claim 1, characterized in that: The detection circuit also includes an auxiliary power supply and a reference circuit. The auxiliary power supply is respectively connected to the drive control circuit, the differential sampling circuit, the hysteresis comparison circuit, the AND gate circuit and the reference circuit for power supply. The reference circuit is used to generate the reference signal, and the reference signal is used to compare with the output signal of the hysteresis comparison circuit.

3. The anti-reverse connection protection circuit according to claim 1, characterized in that: The main circuit also includes a photovoltaic inverter, a second relay and a third relay; The output end of the drive control circuit is connected to the electromagnetic parts of the second relay and the third relay; The contact portion of the second relay is arranged in the positive main circuit, and the contact portion of the second relay is electrically connected to the positive output terminal of the photovoltaic panel and the positive input terminal of the photovoltaic inverter; The contact portion of the third relay is arranged in the negative main circuit, and the contact portion of the third relay is electrically connected to the negative output terminal of the photovoltaic panel and the negative input terminal of the photovoltaic inverter.

4. The anti-reverse connection protection circuit according to claim 3, characterized in that: The main circuit also includes a first relay and a switch tube; Two ends of the contact portion of the first relay are electrically connected to two ends of the switch tube respectively, and the electromagnetic portion of the first relay is electrically connected to the output end of the drive control circuit; The switch tube is arranged in the positive main circuit, and the switch tube is electrically connected to the positive output terminal of the photovoltaic panel and the positive input terminal of the photovoltaic inverter.

5. A reverse connection protection method, characterized in that: Based on the anti-reverse connection protection circuit according to any one of claims 1 to 4, the anti-reverse connection protection method includes: Acquire a sampled voltage of the main circuit, wherein the sampled voltage includes a positive electrode sampled voltage and a negative electrode sampled voltage; If the sampled voltage is greater than a first voltage threshold, the detection circuit is controlled to generate a reverse connection protection signal; Controlling the drive control circuit to output a first control signal and a second control signal through the reverse connection protection signal; turning off the first relay, the second relay, and the third relay based on the first control signal; The switch tube is turned off based on the second control signal.

6. The anti-reverse connection protection method according to claim 5, characterized in that: After obtaining the sampled voltage of the main circuit, the method further includes: If the sampled voltage is less than the first voltage threshold, the detection circuit is controlled to generate a logic control signal; Controlling the drive control circuit to control the second relay and the third relay to be attracted according to the logic control signal; After the second relay and the third relay are energized, controlling the drive control circuit to turn on the switch tube; After a preset period of time, the drive control circuit is controlled to control the first relay to be energized and the switch tube to be turned off.

7. The anti-reverse connection protection method according to claim 6, characterized in that: If the sampled voltage is greater than the first voltage threshold, controlling the detection circuit to generate a reverse connection protection signal includes: When the sampling voltage is greater than the first voltage threshold, a low-level voltage is output through a hysteresis comparison circuit; An AND gate circuit performs a logic comparison on the low-level voltage and then outputs an isolated and amplified low-level signal, wherein the reverse connection protection signal includes the low-level signal.

8. The anti-reverse connection protection method according to claim 5, characterized in that: If the sampled voltage is less than the first voltage threshold, controlling the detection circuit to generate a logic control signal includes: When the sampled voltage is less than the first voltage threshold, a high level voltage is output through the hysteresis comparison circuit; An AND gate circuit performs a logic comparison on the high-level voltage and then outputs an isolated and amplified high-level signal, wherein the logic control signal includes the high-level signal.

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