Photovoltaic module turn-off device and photovoltaic system

Abstract

The embodiment of the utility model relates to a photovoltaic module turn-off device and a photovoltaic system, a photovoltaic module is correspondingly provided with a positive output node and a negative output node, the photovoltaic module is connected in series to a direct current power line between the positive output node and the negative output node, and the photovoltaic module turn-off device comprises a signal receiving module, a signal processing module and a switching module, the acquisition module is used for acquiring on-off control signals transmitted on a direct-current power line; the switch module is respectively connected with the negative electrode of the photovoltaic module and the signal receiving module and is used for switching on and off between the negative electrode and the signal receiving module; the voltage detection module is connected with the positive output node and one end, used for connecting the signal receiving module, of the switch module, and the voltage detection module is used for generating a feedback signal according to the voltage difference between the two ends; and the control module is respectively connected with the signal receiving module, the switch module and the voltage detection module and is used for controlling the switch module to switch according to the on-off control signal and the feedback signal.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of photovoltaic technology, and in particular to a photovoltaic component circuit breaker and a photovoltaic system. Background Art

[0002] At present, photovoltaic systems usually form strings by connecting multiple photovoltaic (PV) modules in series, and then connecting to an inverter to convert DC to AC and connect to the grid. PV modules connected in series will form a dangerous DC high voltage. In order to eliminate the safety risks brought by high voltage electricity, a module circuit breaker is added to the output of each PV module. The outputs of each module circuit breaker are connected in series and then connected to the inverter, so that the voltage output of each PV module can be turned off by the module circuit breaker. In related technologies, RS485 communication cables are usually used to transmit the control signals of the module circuit breaker, which brings great installation and space problems to the photovoltaic system. Utility Model Content

[0003] Based on this, it is necessary to provide a photovoltaic module switch and photovoltaic system that do not require additional communication cables to address the above technical problems.

[0004] In a first aspect, the present application provides a photovoltaic assembly shut-off device, wherein the photovoltaic assembly is respectively provided with a positive output node and a negative output node, and the photovoltaic assembly is connected in series to a DC power line between the positive output node and the negative output node, and the photovoltaic assembly shut-off device comprises:

[0005] A signal receiving module, used for acquiring an on / off control signal transmitted on the DC power line;

[0006] A switch module, connected to the negative electrode of the photovoltaic module and the signal receiving module respectively, and used for switching on and off between the negative electrode and the signal receiving module;

[0007] a voltage detection module, connected to the positive output node and one end of the switch module for connecting to the signal receiving module, respectively, and the voltage detection module is used to generate a feedback signal according to a voltage difference between the two ends;

[0008] The control module is connected to the signal receiving module, the switch module and the voltage detection module respectively, and is used to control the switch module to switch according to the on-off control signal and the feedback signal.

[0009] In one embodiment, the signal receiving module includes:

[0010] a sampling unit, connected to the negative output node and one end of the switch module for connecting to the voltage detection module, respectively, and configured to sample the signal transmitted on the DC power line to generate a sampling signal;

[0011] The filtering unit is connected to the sampling unit and the control module respectively, and is used for filtering the sampling signal to generate the on-off control signal.

[0012] In one embodiment, the sampling unit comprises:

[0013] A current transformer, wherein the primary side of the current transformer is respectively connected to the negative output node and one end of the switch module for connecting to the voltage detection module, and the secondary side of the current transformer is connected to the filter unit to output the sampling signal to the filter unit.

[0014] In one embodiment, the switch module comprises:

[0015] A driving unit, connected to the control module, and configured to generate a driving signal under the control of the control module;

[0016] A switch tube, wherein the gate of the switch tube is connected to the driving unit, the source of the switch tube is connected to the cathode of the photovoltaic component, the drain of the switch tube is connected to the negative output node, and the switch tube is used to be turned on and off under the drive of the driving signal.

[0017] In one embodiment, the voltage detection module includes:

[0018] A voltage regulator tube, wherein a cathode of the voltage regulator tube is connected to the positive output node;

[0019] An optical coupling unit, wherein a first input end of the optical coupling unit is connected to the negative electrode of the voltage regulator tube, a second input end of the optical coupling unit is connected to the negative output node, and an output end of the optical coupling unit is connected to the control module.

[0020] In one embodiment, the voltage detection module further includes:

[0021] The first resistor is connected to the anode of the voltage regulator tube and the first input terminal of the optical coupling unit respectively.

[0022] In one embodiment, the on-off control signal includes a conduction control signal, and the conduction control signal is used to instruct the control module to control the switch tube to be turned on;

[0023] Among them, the Zener diode is used to break down when the switching tube is turned on, the optocoupler unit is used to output a low-level feedback signal when the Zener diode breaks down, and the control module is also used to output a fault indication signal when the conduction control signal is received and the optocoupler unit outputs a high-level feedback signal.

[0024] In one embodiment, the on-off control signal further includes a shut-off control signal, and the shut-off control signal is used to instruct the control module to shut down the switch tube;

[0025] The control module is further configured to control the switch tube to be turned on when the shutdown control signal is received and the optical coupling unit outputs a low-level feedback signal.

[0026] In one embodiment, it also includes:

[0027] The DCDC module is respectively connected to the anode of the photovoltaic module, the voltage detection module and the control module, and is used to generate power supply signals for the voltage detection module and the control module according to the voltage signal output by the photovoltaic module.

[0028] In one embodiment, it also includes:

[0029] a bypass diode, wherein an anode of the bypass diode is connected to one end of the switch module used for connecting to the voltage detection module, and a cathode of the bypass diode is connected to the positive output node;

[0030] A capacitor is connected in parallel with the bypass diode.

[0031] In a second aspect, the present application provides a photovoltaic system, comprising:

[0032] Multiple photovoltaic panels connected together;

[0033] A plurality of photovoltaic assembly disconnectors as described above, wherein the plurality of assembly disconnectors are respectively connected to a plurality of photovoltaic assemblies correspondingly;

[0034] The transmitter is connected to the plurality of component switches respectively and is used for sending the on-off control signal.

[0035] The above-mentioned photovoltaic module circuit breaker and photovoltaic system, when the negative pole of the photovoltaic module is connected to the signal receiving module, the photovoltaic module can output the current generated by photoelectric conversion to the outside through the positive output node and the negative output node via the DC power line. By multiplexing the DC power line, there is no need to set up additional signal lines, and the transmission of the on-off control signal can be realized in the form of power line carrier communication, thereby greatly reducing the space occupied by the signal line for the photovoltaic system. Further, combined with the detection of the voltage detection module, the control module can control the switching of the switch module according to the voltage difference between the positive output node and the negative output node and the received on-off control signal, thereby controlling the on-off of the path between the photovoltaic module and other devices to improve the safety of the photovoltaic system. Therefore, the present application provides a photovoltaic module circuit breaker with a small number of signal cables. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 This is one of the structural schematic diagrams of a photovoltaic module shutdown device according to an embodiment;

[0038] Figure 2 A schematic diagram of photovoltaic module connection according to an embodiment;

[0039] Figure 3 This is a second structural schematic diagram of a photovoltaic module shutdown device according to an embodiment;

[0040] Figure 4 This is a third structural schematic diagram of a photovoltaic module shutdown device according to an embodiment;

[0041] Figure 5 This is a fourth structural schematic diagram of a photovoltaic module shutdown device according to an embodiment;

[0042] Figure 6 FIG. 4 is a schematic structural diagram of a photovoltaic system according to an embodiment of the present invention.

[0043] Component number description:

[0044] Photovoltaic module: 10; signal receiving module: 200; sampling unit: 210; filtering unit: 220; switching module: 300; driving unit: 310; voltage detection module: 400; control module: 500; DCDC module: 600; photovoltaic module shut-off device: 20; transmitter: 30; inverter: 40. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0046] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor without departing from the scope of this application.

[0047] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. "Multiple" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined. "Several" means at least one, such as one, two, etc., unless otherwise clearly and specifically defined.

[0048] The embodiment of the present application provides a photovoltaic module switch. Figure 1 FIG. 1 is a schematic diagram of a photovoltaic module switch according to an embodiment of the present invention. Figure 1 , the photovoltaic assembly 10 is respectively provided with a positive output node VPV1+ and a negative output node Vds-, and the photovoltaic assembly 10 is connected in series to the DC power line between the positive output node VPV1+ and the negative output node Vds-. The photovoltaic assembly 10 can output the current generated by the photoelectric conversion to the outside through the positive output node and the negative output node via the DC power line. It can be understood that other circuit structures can also be connected in series to the DC power line, which is not limited in this embodiment, such as the following signal receiving module 200 and switch module 300. The photovoltaic assembly shut-off device 20 includes a signal receiving module 200, a switch module 300, a voltage detection module 400 and a control module 500.

[0049] in, Figure 2 FIG. 1 is a schematic diagram of a photovoltaic module 10 according to an embodiment of the present invention. Figure 2 In the case where the photovoltaic system includes multiple photovoltaic modules 10, the positive output node VPV1+ of one photovoltaic module 10 is connected to the negative output node Vds- of another photovoltaic module 10 to achieve the series connection of the photovoltaic modules 10, and the multiple photovoltaic modules 10 connected in series form a string ( Figure 2 The output node PV1+ of one string is connected to the output node PV2+ of another string, and together they serve as Figure 2 PV+ shown in FIG, and the output node PV1- of one string is connected to the output node PV2- of another string, and together they serve as Figure 2 The PV-V shown in FIG. 1 is connected to the inverter 40 to convert the DC signal into the AC signal.

[0050] Among them, continue to refer to Figure 1The signal receiving module 200 is used to obtain the on-off control signal transmitted on the DC power line, and the on-off control signal includes a conduction control signal and a shutdown control signal. The switch module 300 is connected to the negative pole of the photovoltaic component 10 and the signal receiving module 200 respectively, and is used to switch the on-off between the negative pole and the signal receiving module 200. The conduction control signal is used to control the switch module 300 to conduct the negative pole of the photovoltaic component 10 and the signal receiving module 200, and the shutdown control signal is used to control the switch module 300 to conduct the negative pole of the photovoltaic component 10 and the signal receiving module 200.

[0051] Specifically, the on-off control signal can be generated by an external device and loaded on the DC power line. For example, when the photovoltaic module 10 needs to be repaired, the operator can operate the external device to generate a shutdown control signal. The shutdown control signal disconnects different photovoltaic modules 10, thereby eliminating the DC high voltage in the photovoltaic system and reducing the risk of electric shock. On the contrary, the operator can also control the external device to generate a conduction control signal after completing the maintenance to enable the photovoltaic system to output normally. It can be understood that if the switch controls the on-off only based on the output parameters of the photovoltaic module 10 itself, it is easy to misjudge, and when danger occurs, there is a risk of fire caused by failure to shut down in time. Therefore, in this embodiment, obtaining the on-off control signal from the external device can greatly improve the safety of the photovoltaic system. Moreover, the power line carrier communication (Power Line Carrier, PLC) method of this embodiment can save the laying of communication cables, low cost and good stability.

[0052] The voltage detection module 400 is respectively connected to the positive output node VPV1+ and one end of the switch module 300 for connecting to the signal receiving module 200, and the voltage detection module 400 is used to generate a feedback signal according to the voltage difference between the two ends. That is, the voltage detection module 400 is used to detect the voltage output state of the photovoltaic component 10, so as to automatically determine whether the photovoltaic component 10 has an output voltage, so as to determine whether the states of the photovoltaic component 10 and the switch module 300 are abnormal.

[0053] The control module 500 is respectively connected to the signal receiving module 200, the switch module 300, and the voltage detection module 400, and is used to control the switch module 300 to switch according to the on-off control signal and the feedback signal. By integrating the on-off control signal and the feedback signal, not only can the external device control the circuit breaker, but also a certain degree of control can be performed based on the output state of the photovoltaic module 10, so that when the communication with the external device is shut down and the photovoltaic module 10 or the switch module 300 is abnormal, the corresponding operation is performed in time, thereby further improving the reliability of the circuit breaker.

[0054] In this embodiment, when the negative pole of the photovoltaic component 10 is connected to the signal receiving module 200, the photovoltaic component 10 can output the current generated by the photoelectric conversion to the outside through the positive output node VPV1+ and the negative output node Vds- via the DC power line. By reusing the DC power line, the transmission of the on-off control signal can be realized in the form of power line carrier communication without setting up additional signal lines, thereby greatly reducing the space occupied by the signal line for the photovoltaic system. Further, in combination with the detection of the voltage detection module 400, the control module 500 can control the switch module 300 to switch according to the voltage difference between the positive output node VPV1+ and the negative output node Vds- and the received on-off control signal, thereby controlling the on-off of the path between the photovoltaic component 10 and other devices to improve the safety of the photovoltaic system. Therefore, the present application provides a photovoltaic component circuit breaker 20 with a small number of signal cables.

[0055] Figure 3 This is a second structural diagram of a photovoltaic module switch 20 according to an embodiment of the present invention. Figure 3 In one embodiment, the signal receiving module 200 includes a sampling unit 210 and a filtering unit 220 .

[0056] Among them, the sampling unit 210 is respectively connected to the negative output node Vds- and one end of the switch module 300 for connecting the voltage detection module 400, and the sampling unit 210 is used to sample the signal transmitted on the DC power line to generate a sampling signal. Optionally, the sampling unit 210 may include a coupler, which can separate the power frequency signal and the carrier signal transmitted on the power line, thereby ensuring that the carrier signal can be processed and analyzed independently of the power transmission. The coupler can be, for example, a coupling capacitor, which allows high-frequency carrier signals to pass through and can simultaneously block the high voltage of the power line, thereby protecting communication equipment and personal safety. The filtering unit 220 is respectively connected to the sampling unit 210 and the control module 500, and the filtering unit 220 is used to filter the sampling signal to generate the on-off control signal. Specifically, the filtering unit 220 can filter out the interference signal in the signal transmitted on the DC power line, and the filtering method of the filtering unit 220 can be, but not limited to, a limiting filtering method, a median filtering method, an average filtering method, a hardware filtering method, etc., which is not limited in this embodiment. In this embodiment, by providing a filtering module, the accuracy of the on-off control signal output by the signal receiving module 200 can be greatly improved.

[0057] Continue to refer Figure 3In one embodiment, the sampling unit 210 includes a current transformer L1. The primary side of the current transformer L1 is respectively connected to the negative output node Vds- and one end of the switch module 300 for connecting to the voltage detection module 400, and the secondary side of the current transformer L1 is connected to the filter unit 220 to output the sampling signal to the filter unit 220. The current transformer L1 is a device that works on the principle of electromagnetic induction and can convert a large current on the primary side into a small current on the secondary side. In this embodiment, by using the current transformer L1, the measurement and monitoring of the sampling signal can be greatly facilitated.

[0058] Continue to refer Figure 3 In one embodiment, the switch module 300 includes a drive unit 310 and a switch tube Q1. The drive unit 310 is connected to the control module 500 and is used to generate a drive signal under the control of the control module 500. The gate of the switch tube Q1 is connected to the drive unit 310, the source of the switch tube Q1 is connected to the cathode of the photovoltaic component 10, the drain of the switch tube Q1 is connected to the negative output node Vds-, and the switch tube Q1 is used to turn on and off under the drive of the drive signal. The drive module can process the signal output by the control module 500 to generate a drive signal with stronger driving capability to achieve on-off control of the switch tube Q1. Optionally, the switch tube Q1 can be an N-type enhancement MOSFET. Accordingly, when the drive signal makes the gate-source voltage of the switch tube Q1 less than the threshold voltage, the switch tube Q1 is turned off; when the drive signal makes the gate-source voltage of the switch tube Q1 greater than the threshold voltage, the switch tube Q1 is turned on.

[0059] Continue to refer Figure 3 In one embodiment, the voltage detection module 400 includes a voltage regulator tube Z1 and an optocoupler unit U1. The cathode of the voltage regulator tube Z1 is connected to the positive output node VPV1+. The first input terminal of the optocoupler unit U1 is connected to the cathode of the voltage regulator tube Z1, the second input terminal of the optocoupler unit U1 is connected to the negative output node Vds-, and the output terminal of the optocoupler unit U1 is connected to the control module 500. Specifically, when the switch tube Q1 is turned on, the output voltage of the photovoltaic module 10 breaks through the voltage regulator tube Z1, and the optocoupler unit U1 is turned on, and the optocoupler unit U1 outputs a low-level feedback signal to the control module 500. When the switch tube Q1 is turned off, the light-emitting diode of the optocoupler unit U1 is turned off, and the optocoupler unit U1 outputs a high-level feedback signal to the control module 500. In this embodiment, through the voltage regulator tube Z1 and the optocoupler unit U1, rapid feedback of the voltage can be achieved, so that the control module 500 monitors the on-off state of the switch tube Q1 and the output state of the photovoltaic module 10.

[0060] In one embodiment, the voltage detection module 400 further includes a first resistor R1, which is connected to the anode of the voltage regulator tube Z1 and the first input terminal of the optical coupling unit U1 respectively. The first resistor R1 is used to limit the current between the voltage regulator tube Z1 and the optical coupling unit U1 to protect the optical coupling unit U1.

[0061] In one embodiment, the on-off control signal includes a conduction control signal, and the conduction control signal is used to instruct the control module 500 to control the switch tube Q1 to be turned on. Among them, the voltage regulator tube Z1 is used to break down when the switch tube Q1 is turned on, and the optical coupling unit U1 is used to output a low-level feedback signal when the voltage regulator tube Z1 breaks down. The control module 500 is also used to output a fault indication signal when the conduction control signal is received and the optical coupling unit U1 outputs a high-level feedback signal. It can be understood that if the control module 500 is also used to receive the conduction control signal, the switch tube Q1 should be turned on, but the optical coupling unit U1 outputs a high-level feedback signal indicating that the switch tube Q1 is not turned on. That is, there is a fault in the switch tube Q1 or the signal transmission path between the control module 500 and the switch tube Q1. In this case, the control module 500 outputs a fault indication signal to the external device, and the operator can promptly repair the switch module 300, thereby improving the reliability of the photovoltaic component circuit breaker 20. Optionally, the control module 500 may send the fault indication signal to an external device via a wired communication module or a wireless communication module.

[0062] In one of the embodiments, when the control module 500 receives a conduction control signal and the switch tube Q1 is turned on, the output voltage of the photovoltaic component 10 breaks down the voltage regulator tube Z1, and the output voltage of the photovoltaic component 10 passes through the current limiting resistor and the light-emitting diode of the optocoupler unit U1 to turn on the optocoupler unit U1. The optocoupler unit U1 outputs a low-level feedback signal to the control module 500, and the control module 500 thereby determines that the switch tube Q1 is working normally.

[0063] In one embodiment, the on-off control signal also includes a shutdown control signal, and the shutdown control signal is used to instruct the control module 500 to control the switch tube Q1 to be turned off. Wherein, the control module 500 is also used to control the switch tube Q1 to be turned on when the shutdown control signal is received and the optocoupler unit U1 outputs a low-level feedback signal. It can be understood that the photovoltaic component 10 also has a safety risk of backflow. If the voltage of one of the strings is lower than the voltage of other parallel strings for some reason, then in the absence of an anti-reverse diode between the strings, the current will flow in reverse into the string with lower voltage. If the switch tube Q1 connected to the photovoltaic component 10 with lower voltage is in the off state at this time, this large current will flow into the photovoltaic component 10 through the body diode of the switch tube Q1, which can easily burn the switch tube Q1. In this embodiment, when the control module 500 receives a shutdown control signal, or does not receive an on / off control signal and the switch tube Q1 is turned off, when there is a reverse current between different branches, the reverse current will flow through the parasitic body diode of the switch tube Q1, the output voltage will break through the voltage regulator tube Z1, and pass through the current limiting resistor and the light-emitting diode of the optocoupler, so that the optocoupler module is turned on and outputs a low level to the control module 500. When the control module 500 detects a low-level feedback signal, the switch tube Q1 is controlled to be turned on, so that the reverse current passes through the switch tube Q1 to reduce the loss of the entire switch and prevent the switch tube Q1 from being overheated and damaged, thereby having a reverse current protection function between strings.

[0064] Figure 4 This is a third structural diagram of a photovoltaic module switch 20 according to an embodiment of the present invention. Figure 4 In one embodiment, the photovoltaic module shut-off device 20 further includes a DCDC module 600. The DCDC module 600 is respectively connected to the anode of the photovoltaic module 10, the voltage detection module 400 and the control module 500, and is used to generate power supply signals for the voltage detection module 400 and the control module 500 according to the voltage signal output by the photovoltaic module 10. The DCDC module 600 can be connected to the optical coupling unit U1 via the second resistor R2. In this embodiment, by setting the DCDC module 600, the power supply signal can be flexibly adjusted, so that the voltage detection module 400 and the control module 500 can work stably.

[0065] Figure 5 FIG. 4 is a schematic diagram of the structure of a photovoltaic module switch 20 according to an embodiment of the present invention. Figure 5In one embodiment, the photovoltaic module switch 20 further includes a bypass diode D1 and a capacitor C1. The anode of the bypass diode D1 is connected to one end of the switch module 300 for connecting to the voltage detection module 400, and the cathode of the bypass diode D1 is connected to the positive output node VPV1+. The capacitor C1 is connected in parallel with the bypass diode D1. In this embodiment, by setting the bypass diode D1, when part of the photovoltaic module 10 is damaged or shaded, the current of the photovoltaic module 10 that is still generating current can bypass the shaded part, so that the entire photovoltaic system can continue to operate normally. The capacitor can help smooth the fluctuations of direct current, reduce the noise in voltage and current, and provide a more stable power output.

[0066] based on Figure 5 The schematic diagram of the structure of the photovoltaic module switch 20 is shown, and the working mechanism of the photovoltaic module switch 20 is described in detail here. The sampling unit 210 is suitable for receiving the signal sent by the external transmitter to the control module 500, and the interference signal in the sampling signal is filtered out by the filtering unit 220 to generate an on-off control signal, and send it to the control module 500. When the control module 500 receives the on-control signal, and the driving unit 310 drives the switch tube Q1 to turn on, the output voltage of the photovoltaic module 10 breaks through the voltage regulator tube Z1, and the output voltage of the photovoltaic module 10 passes through the first resistor R1 and the light-emitting diode of the optical coupling unit U1, so that the optical coupling unit U1 is turned on and outputs a low-level feedback signal to the control module 500. The control module 500 detects the low-level feedback signal and determines that the switch tube Q1 is working normally. When the control module 500 receives the on-control signal, but the switch tube Q1 is still off, the light-emitting diode of the optocoupler unit U1 is turned off, and the optocoupler unit U1 outputs a high-level feedback signal to the control module 500. The control module 500 detects the high-level feedback signal and determines that the switch tube Q1 is faulty. When the control module 500 receives the off-control signal and the drive unit 310 drives the switch tube Q1 to turn off, if there is a reverse current, the reverse current will flow through the parasitic body diode of the switch tube Q1, and the output voltage will break through the voltage regulator tube Z1 to turn on the optocoupler unit U1. The optocoupler unit U1 outputs a low-level feedback signal to the control module 500. After the control module 500 detects the low-level feedback signal, it controls the switch tube Q1 to turn on.

[0067] It should be noted that the on-off control signal and feedback signal of each embodiment of the present application are both high and low level signals, and the signal output by the control module 500 can also be a high and low level signal. Therefore, the control module 500 can be implemented by a logic digital circuit, in which one output pin is used to connect the drive module, and the other output pin is used to output a fault indication signal. Specifically, when the control module 500 receives a low level feedback signal, the control module 500 controls the drive module to output a high level drive signal so that the switch tube Q1 of the N-type enhancement MOSFET is turned on. When the control module 500 receives a shutdown control signal and the feedback signal is a high level, the control module 500 controls the drive module to output a low level drive signal so that the switch tube Q1 of the N-type enhancement MOSFET is disconnected. When the control module 500 receives a conduction control signal and the feedback signal is a high level, a fault indication signal is output.

[0068] The present application also provides a photovoltaic system, Figure 6 is a schematic diagram of the structure of a photovoltaic system according to an embodiment, referring to Figure 6 The photovoltaic system includes a plurality of photovoltaic modules 10, a plurality of photovoltaic module disconnectors 20 as described above, and a transmitter 30. The connection method between the plurality of photovoltaic modules 10 can refer to Figure 2 , which will not be described in detail here. The plurality of component switches are respectively connected to the plurality of photovoltaic components 10. The transmitter 30 is respectively connected to the plurality of component switches for sending the on-off control signal. Furthermore, the photovoltaic system further includes an inverter 40 to realize the DC to AC conversion of the voltage signal output by the photovoltaic component.

[0069] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] The above-described embodiments only express several implementation methods of the embodiments of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the utility model patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the embodiments of the present application, and these all belong to the protection scope of the embodiments of the present application. Therefore, the protection scope of the patent of the embodiments of the present application shall be subject to the attached claims.

Claims

1. A photovoltaic module switch, characterized in that: The photovoltaic components are respectively provided with a positive output node and a negative output node, the photovoltaic components are connected in series to the DC power line between the positive output node and the negative output node, and the photovoltaic component switch includes: A signal receiving module, used for acquiring an on / off control signal transmitted on the DC power line; A switch module, connected to the negative electrode of the photovoltaic module and the signal receiving module respectively, and used for switching on and off between the negative electrode and the signal receiving module; a voltage detection module, connected to the positive output node and one end of the switch module for connecting to the signal receiving module, respectively, and configured to generate a feedback signal according to a voltage difference between the two ends; The control module is connected to the signal receiving module, the switch module and the voltage detection module respectively, and is used to control the switch module to switch according to the on-off control signal and the feedback signal.

2. The photovoltaic module shut-off device according to claim 1, characterized in that: The signal receiving module comprises: a sampling unit, connected to the negative output node and one end of the switch module for connecting to the voltage detection module, respectively, and configured to sample the signal transmitted on the DC power line to generate a sampling signal; The filtering unit is connected to the sampling unit and the control module respectively, and is used for filtering the sampling signal to generate the on-off control signal.

3. The photovoltaic module shut-down device according to claim 2, characterized in that: The sampling unit comprises: A current transformer, wherein the primary side of the current transformer is respectively connected to the negative output node and one end of the switch module for connecting to the voltage detection module, and the secondary side of the current transformer is connected to the filter unit to output the sampling signal to the filter unit.

4. The photovoltaic module shut-off device according to any one of claims 1 to 3, characterized in that: The switch module includes: A driving unit, connected to the control module, and configured to generate a driving signal under the control of the control module; A switch tube, wherein the gate of the switch tube is connected to the driving unit, the source of the switch tube is connected to the cathode of the photovoltaic component, the drain of the switch tube is connected to the negative output node, and the switch tube is used to be turned on and off under the drive of the driving signal.

5. The photovoltaic module shut-off device according to claim 4, characterized in that: The voltage detection module comprises: A voltage regulator tube, wherein a cathode of the voltage regulator tube is connected to the positive output node; An optical coupling unit, wherein a first input end of the optical coupling unit is connected to the negative electrode of the voltage regulator tube, a second input end of the optical coupling unit is connected to the negative output node, and an output end of the optical coupling unit is connected to the control module.

6. The photovoltaic module shut-off device according to claim 5, characterized in that: The voltage detection module also includes: The first resistor is connected to the anode of the voltage regulator tube and the first input terminal of the optical coupling unit respectively.

7. The photovoltaic module shut-off device according to claim 5, characterized in that: The on-off control signal includes a conduction control signal, and the conduction control signal is used to instruct the control module to control the switch tube to be turned on; Among them, the Zener diode is used to break down when the switching tube is turned on, the optocoupler unit is used to output a low-level feedback signal when the Zener diode breaks down, and the control module is also used to output a fault indication signal when the conduction control signal is received and the optocoupler unit outputs a high-level feedback signal.

8. The photovoltaic module shut-off device according to claim 5, characterized in that: The on-off control signal also includes a shut-off control signal, and the shut-off control signal is used to instruct the control module to control the switch tube to shut down; The control module is further configured to control the switch tube to be turned on when the shutdown control signal is received and the optical coupling unit outputs a low-level feedback signal.

9. The photovoltaic module shut-off device according to claim 1, characterized in that: Also includes: The DCDC module is respectively connected to the anode of the photovoltaic module, the voltage detection module and the control module, and is used to generate power supply signals for the voltage detection module and the control module according to the voltage signal output by the photovoltaic module.

10. The photovoltaic module shut-off device according to claim 1, characterized in that: Also includes: a bypass diode, wherein an anode of the bypass diode is connected to one end of the switch module used for connecting to the voltage detection module, and a cathode of the bypass diode is connected to the positive output node; A capacitor is connected in parallel with the bypass diode.

11. A photovoltaic system, characterized in that: include: Multiple photovoltaic panels connected together; A plurality of photovoltaic assembly shut-off devices according to any one of claims 1 to 10, wherein the plurality of assembly shut-off devices are respectively connected to the plurality of photovoltaic assemblies; The transmitter is connected to the plurality of component switches respectively and is used for sending the on-off control signal.

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