Photovoltaic string and photovoltaic system

Abstract

The invention discloses a photovoltaic string and a photovoltaic system, and relates to the technical field of photovoltaic safety, the photovoltaic string comprises a plurality of photovoltaic modules, and every two adjacent photovoltaic modules are connected in series through an inter-plate connecting line; the first magnetic ring is arranged on a connecting line between a head-end photovoltaic module or a tail-end photovoltaic module in the photovoltaic group string and the inverter in a sleeving manner, the emitter is electrically connected with the first magnetic ring, and the emitter is used for sending an alternating current signal with a preset frequency to the photovoltaic group string through the first magnetic ring; the multiple turn-off assemblies are arranged on the inter-board connecting lines respectively, each turn-off assembly comprises a carrier extraction module and a switch control module used for controlling on-off of a direct-current loop of the corresponding inter-board connecting line, and the carrier extraction modules are used for extracting alternating-current electric signals from the inter-board connecting lines and supplying power to the switch control modules. According to the invention, the production cost can be reduced, the generating capacity of the photovoltaic system is not consumed, and the operation stability of the photovoltaic system is improved.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic safety technology, and in particular to a photovoltaic string and a photovoltaic system. Background Art

[0002] Safety is very important in photovoltaic systems. Photovoltaic strings are connected in series with photovoltaic modules through photovoltaic terminals and DC cables to power generation equipment such as the subsequent inverter. Usually, the voltage of a single photovoltaic module is 10~80V, and the voltage of a whole photovoltaic string is 1000V~1500V, which is high-voltage DC. In special circumstances such as fire, if the photovoltaic strings are not disconnected one by one, the high voltage will still exist, which is very dangerous for firefighters and they often miss the first time to put out the fire.

[0003] In order to quickly disconnect the photovoltaic strings, it is necessary to equip the photovoltaic power generation system with a shutdown component. The photovoltaic strings are disconnected by controlling the shutdown component to disconnect, thereby reducing the voltage of the entire photovoltaic string to a safe voltage range for the human body. At present, the shutdown component and the photovoltaic component are mainly connected in parallel. However, since the shutdown component connected to the photovoltaic component in parallel is powered by the photovoltaic component and is affected by the energy of the photovoltaic component, the shutdown component cannot work normally on rainy days or in weak light, and its own power consumption also affects the power generation of the entire photovoltaic system. In addition, a shutdown component must be installed under each photovoltaic component, further increasing the cost and the complexity of installation and maintenance. Summary of the invention

[0004] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art, and to provide a photovoltaic string and a photovoltaic system, which can reduce production costs without consuming the power generation of the photovoltaic system and improve the stability of operation.

[0005] In a first aspect, an embodiment of the present invention provides a photovoltaic string, which is applied to a photovoltaic system, wherein the photovoltaic system includes an inverter and a transmitter; the input end of the inverter is connected to the photovoltaic string, and the output end is connected to a power grid; the photovoltaic string includes: a plurality of photovoltaic components, two adjacent photovoltaic components are connected in series via an inter-board connecting line; a first magnetic ring is sleeved on a connecting line between a head-end photovoltaic component or an end photovoltaic component in the photovoltaic string and the inverter, the transmitter is electrically connected to the first magnetic ring, and the transmitter is used to send an AC signal of a preset frequency to the photovoltaic string through the first magnetic ring; a plurality of shutdown components are respectively arranged on the inter-board connecting lines, and the shutdown components include a carrier extraction module and a switch control module for controlling the on and off of a DC circuit of the inter-board connecting line, and the carrier extraction module is used to extract the AC signal from the inter-board connecting line and supply power to the switch control module.

[0006] A photovoltaic string provided according to an embodiment of the present invention has at least the following beneficial effects: the input end of the inverter is connected to the photovoltaic string, the output end is connected to the power grid, two adjacent photovoltaic modules in the photovoltaic string are connected in series through an inter-panel connection line, a shutdown module is arranged on the inter-panel connection line, a first magnetic ring is sleeved on the connection line between the head photovoltaic module or the end photovoltaic module in the photovoltaic string and the inverter, the transmitter is electrically connected to the first magnetic ring, the transmitter is used to send an AC signal of a preset frequency to the photovoltaic string through the first magnetic ring, a carrier extraction module in each shutdown module extracts the AC signal from the inter-panel connection line, each carrier extraction module supplies power to the switch control module, the switch control module controls the DC circuit of the inter-panel connection line to be turned on, so that the entire photovoltaic string has power and the back-end power generation equipment starts to work normally; because the switch control module can control the on and off of the DC circuit of the inter-panel connection line, when encountering an emergency, the switch control modules of all the shutdown modules control the DC circuit of the inter-panel connection line to turn on and off. The current loop is disconnected, and the voltage of the entire photovoltaic string can be quickly reduced to a safe voltage range acceptable to the human body, without affecting the timely adoption of measures to deal with emergencies; compared with the solution in which the photovoltaic components and the shutdown components are connected in parallel, on the one hand, each shutdown component is connected to the photovoltaic component in series, and only two cables need to be set, which saves the cost of the whole machine and reduces the complexity of installation and maintenance, which is conducive to improving installation efficiency. On the other hand, the shutdown component extracts the AC signal from the inter-board connecting line through the carrier extraction module to realize power supply, without obtaining energy from the photovoltaic component, and does not consume the power generation of the photovoltaic system. At the same time, it also avoids the situation where the shutdown component cannot work normally due to unstable power generation of some photovoltaic components, thereby improving the stability of the operation of the photovoltaic system. Moreover, compared with the solution in which the photovoltaic components and the shutdown components are connected in parallel, a shutdown component must be installed under each photovoltaic component, and only one shutdown component is connected between two adjacent photovoltaic components, which reduces the use of shutdown components and further saves costs.

[0007] According to some embodiments of the present invention, a photovoltaic string is provided, wherein the switch control module includes a power supply module, a control module and a switch module, the carrier extraction module is connected to the input end of the power supply module, the output end of the power supply module is connected to the input end of the control module, the output end of the control module is connected to the switch module, and the switch module is connected to the inter-board connecting line to form the DC circuit.

[0008] According to some embodiments of the present invention, a photovoltaic string is provided, the switch module includes a drive module and a first MOS tube, the output end of the control module is connected to the input end of the drive module, the output end of the drive module is connected to the first input end of the first MOS tube, and the inter-board connecting line is connected to the first output end of the first MOS tube and the second output end of the first MOS tube to form the DC circuit.

[0009] According to a photovoltaic string provided by some embodiments of the present invention, the carrier extraction module includes a second magnetic ring and a first filtering module, the second magnetic ring is sleeved on the inter-board connecting line, the second magnetic ring is connected to the input end of the first filtering module, and the output end of the first filtering module is connected to the switch control module.

[0010] According to a photovoltaic string provided by some embodiments of the present invention, the carrier extraction module includes a first inductor and a second filtering module, the first inductor is connected to the inter-board connecting line, the first inductor is connected to the input end of the second filtering module, and the output end of the second filtering module is connected to the switch control module.

[0011] According to a photovoltaic string provided by some embodiments of the present invention, when the transmitter is powered off or the transmitter stops sending the AC signal of the preset frequency, the DC circuit of the inter-panel connecting line is disconnected.

[0012] According to a photovoltaic string provided by some embodiments of the present invention, when the output end of the control module outputs a high level, the DC circuit formed by connecting the switch module and the inter-board connecting line is turned on.

[0013] According to a photovoltaic string provided by some embodiments of the present invention, when the output end of the driving module outputs a high level, the DC circuit formed by connecting the inter-board connecting line with the first output end of the first MOS tube and the second output end of the first MOS tube is turned on.

[0014] In a second aspect, an embodiment of the present invention provides a photovoltaic system, comprising an inverter, a transmitter, and a photovoltaic string as described in any one of the embodiments of the first aspect, wherein an output end of the inverter is connected to a power grid.

[0015] According to some embodiments of the present invention, a photovoltaic system is provided, further comprising a host computer and a first communication module, wherein the first communication module is connected to the transmitter, and the first communication module is in communication connection with the host computer.

[0016] According to a photovoltaic system provided by some embodiments of the present invention, when the host computer sends a first control instruction to the transmitter through the first communication module, the transmitter is powered off.

[0017] According to a photovoltaic system provided by some embodiments of the present invention, when the host computer sends a second control instruction to the transmitter through the first communication module, the transmitter stops sending an alternating current signal of a preset frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0019] The present invention is further described below in conjunction with the accompanying drawings and embodiments; Figure 1 is a structural diagram of a photovoltaic system provided by an embodiment of the present invention; Figure 2 is a structural diagram of a photovoltaic assembly and a shutdown device connected in parallel provided by an embodiment of the present invention; Figure 3 is a structural diagram of another photovoltaic system provided by an embodiment of the present invention; Figure 4 is a structural diagram of a first type of shutdown device in a photovoltaic string provided by an embodiment of the present invention; Figure 5 is a structural diagram of a second type of shutdown device in a photovoltaic string provided by an embodiment of the present invention; Figure 6 is a structural diagram of a third type of shutdown device in a photovoltaic string provided by an embodiment of the present invention; Figure 7 is a structural diagram of a fourth type of shutdown device in a photovoltaic string provided by an embodiment of the present invention; Figure 8 It is a structural diagram of the fifth type of shutdown device in the photovoltaic string provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0020] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0021] In the description of the present invention, if there is a description of first and second, it is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0022] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0023] Safety is very important in photovoltaic systems. Photovoltaic strings are connected in series with photovoltaic modules through photovoltaic terminals and DC cables to power generation equipment such as the subsequent inverter. Usually, the voltage of a single photovoltaic module is 10~80V, and the voltage of the entire photovoltaic string is 1000V~1500V, which is high-voltage DC. In special circumstances such as fire, if the photovoltaic strings are not disconnected one by one, the high voltage will still exist, which is very dangerous for firefighters and they often miss the first time to put out the fire.

[0024] In order to quickly disconnect the photovoltaic string, it is necessary to equip the photovoltaic power generation system with a shutdown component RSD. By controlling the shutdown component to disconnect, the photovoltaic string is disconnected, and the voltage of the entire photovoltaic string is reduced to a safe voltage range for human body. At present, the connection method of the shutdown component and the photovoltaic component is mainly parallel connection. Figure 1 , Figure 2 Specifically, a power supply module, a control module, a MOS tube and a communication module are provided in the shutdown component. The power supply module obtains power from the photovoltaic component. The control module is respectively connected to the power supply module, the communication module and the MOS tube. The MOS tube is used to control the on and off of adjacent photovoltaic components, so that the photovoltaic string can be quickly disconnected in case of an emergency. However, since the shutdown component connected to the photovoltaic panel in parallel is powered by the photovoltaic component, on the one hand, the shutdown component needs to be provided with four DC cables, of which two DC cables are respectively connected to the positive and negative ends of the photovoltaic component, and the other two cables are used to connect two adjacent shutdown components, which increases the cost of the whole machine; on the other hand, affected by the energy supply of the photovoltaic component, on rainy days or under weak light, the power supply of the photovoltaic component is insufficient, so that the shutdown component cannot work normally on rainy days or under weak light, and the power consumption of the shutdown component itself also affects the power generation of the entire photovoltaic system; in addition, a shutdown component must be installed under each photovoltaic panel, which further increases the cost and increases the complexity of installation and maintenance.

[0025] Based on this, the embodiments of the present invention provide a photovoltaic string and a photovoltaic system, which can reduce production costs without consuming the power generated by the photovoltaic system, and improve the stability of the operation of the photovoltaic system.

[0026] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0027] Reference Figure 3 , Figure 4The first aspect of the present invention provides a photovoltaic string, which is applied to a photovoltaic system. The photovoltaic system includes an inverter and a transmitter 300; the input end of the inverter is connected to the photovoltaic string, and the output end is connected to the power grid; the photovoltaic string includes: a plurality of photovoltaic modules 100, and two adjacent photovoltaic modules 100 are connected in series through an inter-board connecting line 101; a first magnetic ring 310 is sleeved on the connecting line between the head photovoltaic module 110 or the end photovoltaic module 120 in the photovoltaic string and the inverter, the transmitter 300 is electrically connected to the first magnetic ring 310, and the transmitter 300 is used to send an AC signal of a preset frequency to the photovoltaic string through the first magnetic ring 310; a plurality of shutdown components 200 are respectively arranged on the inter-board connecting line 101, and the shutdown component 200 includes a carrier extraction module 210 and a switch control module 220 for controlling the on and off of the DC circuit of the inter-board connecting line 101, and the carrier extraction module 210 is used to extract the AC signal from the inter-board connecting line 101 and supply power to the switch control module 220.

[0028] According to a photovoltaic string provided by an embodiment of the present invention, the input end of the inverter is connected to the photovoltaic string, the output end is connected to the power grid, two adjacent photovoltaic modules 100 in the photovoltaic string are connected in series through an inter-board connecting line 101, the shut-off component 200 is arranged on the inter-board connecting line 101, the first magnetic ring 310 is sleeved on the connecting line between the head photovoltaic module 110 or the end photovoltaic module 120 in the photovoltaic string and the inverter, the transmitter 300 is electrically connected to the first magnetic ring 310, and the transmitter 300 is used to send an AC signal of a preset frequency to the photovoltaic string through the first magnetic ring 310, and each The carrier extraction module 210 in each shutdown component 200 extracts the AC signal from the inter-panel connection line 101, and each carrier extraction module 210 supplies power to the switch control module 220, which controls the DC circuit of the inter-panel connection line 101 to be turned on, so that the entire photovoltaic string is powered and the back-end power generation equipment starts to work normally; since the switch control module 220 can control the on and off of the DC circuit of the inter-panel connection line 101, when encountering an emergency, the switch control modules 220 of all the shutdown components 200 control the DC circuit of the inter-panel connection line 101 to be disconnected, and the entire photovoltaic string is powered on. The voltage of the string can be quickly reduced to a safe voltage range acceptable to the human body, without affecting the timely adoption of measures to deal with emergencies; compared with the solution in which the photovoltaic components 100 and the shutdown components 200 are connected in parallel, on the one hand, each shutdown component 200 is connected to the photovoltaic component 100 in series, and only two cables are required, which saves the cost of the whole machine and reduces the complexity of installation and maintenance, which is conducive to improving the installation efficiency; on the other hand, the shutdown component 200 extracts the AC signal from the inter-board connection line 101 through the carrier extraction module 210 to realize power supply, without the need for To obtain energy from the photovoltaic module 100, the power generation of the photovoltaic system will not be consumed. At the same time, it also avoids the situation where the shutdown component 200 cannot work normally due to unstable power generation of some photovoltaic modules 100, thereby improving the stability of the operation of the photovoltaic system. In addition, compared with the solution in which the photovoltaic module 100 and the shutdown component 200 are connected in parallel and a shutdown component 200 is installed under each photovoltaic module 100, only one shutdown component 200 is connected between two adjacent photovoltaic modules 100, thereby reducing the use of the shutdown component 200 and further saving costs.

[0029] It should be noted that the transmitter 300 can be powered by a power generation device on the inverter side or by its own power module.

[0030] It should be noted that the transmitter 300 is used to send an AC signal of a preset frequency to the photovoltaic string through the first magnetic ring 310 , that is, the transmitter 300 is used to send a carrier signal of a preset frequency to the photovoltaic string through the first magnetic ring 310 .

[0031] It should be noted that the inter-board connecting line 101 is connected to some devices in the switch control module 220 to form a DC circuit of the inter-board connecting line 101. The on-off of the DC circuit can be further controlled by controlling the on-off of some devices in the switch control module 220 connected to the inter-board connecting line 101. The carrier extraction module 210 is connected to the switch control module 220 and supplies power to the switch control module 220.

[0032] It should be noted that a capacitor element is provided in the inter-board connection line 101 as a path for the AC signal of a preset frequency sent by the transmitter 300 , and the carrier extraction module 210 is used to extract the AC signal from the inter-board connection line 101 and supply power to the switch control module 220 .

[0033] According to a photovoltaic string provided by some embodiments of the present invention, when the transmitter 300 is powered off or the transmitter 300 stops sending an AC signal of a preset frequency, the DC circuit of the inter-panel connecting line 101 is disconnected.

[0034] It is understandable that when the transmitter 300 is powered off, the transmitter 300 cannot send an AC signal of a preset frequency to the photovoltaic string through the first magnetic ring 310 .

[0035] It should be noted that when the transmitter 300 is powered off, or the transmitter 300 stops sending the AC signal of the preset frequency, the carrier extraction module 210 cannot extract the AC signal from the inter-board connecting line 101, and the carrier extraction module 210 cannot supply power to the switch control module 220, thereby making it impossible for the switch control module 220 to control the conduction of the DC circuit of the inter-board connecting line 101.

[0036] According to some embodiments of the present invention, a photovoltaic string is provided, referring to Figure 5 The switch control module 220 includes a power supply module 221, a control module 222 and a switch module 223. The carrier extraction module 210 is connected to the input end of the power supply module 221, the output end of the power supply module 221 is connected to the input end of the control module 222, the output end of the control module 222 is connected to the switch module 223, and the switch module 223 is connected to the inter-board connection line 101 to form a DC circuit.

[0037] It should be noted that the carrier extraction module 210 is used to extract the AC signal from the inter-board connection line 101 and supply power to the power supply module 221. The power supply module 221 is connected to the control module 222. The power supply module 221 is used to provide the control module 222 with a stable voltage that meets its requirements, ensuring that the control module 222 can obtain the required electrical energy, thereby maintaining the stable operation of the shutdown component 200.

[0038] According to a photovoltaic string provided by some embodiments of the present invention, when the output terminal of the control module 222 outputs a high level, the DC circuit formed by connecting the switch module 223 and the inter-panel connecting line 101 is turned on.

[0039] It should be noted that the control module 222 is used to control the on and off of the switch module 223. When the switch module 223 is turned on, the switch module 223 is connected to the inter-board connection line 101 to form a DC circuit that is turned on. When the switch module 223 is turned off, the switch module 223 is connected to the inter-board connection line 101 to form a DC circuit that is turned off. When the output end of the control module 222 outputs a high level, the switch module 223 is turned on, so the DC circuit formed by the switch module 223 and the inter-board connection line 101 is turned on. When the transmitter 300 is powered off, or the transmitter 300 stops sending the preset frequency The carrier extraction module 210 cannot extract the AC signal from the inter-board connecting line 101, the carrier extraction module 210 cannot supply power to the power supply module 221, the control module 222 connected to the power supply module 221 stops working, the output end of the control module 222 cannot output a high level, the switch module 223 is disconnected, and the DC circuit formed by the switch module 223 and the inter-board connecting line 101 is disconnected, so that the photovoltaic string is disconnected, and the voltage of the entire photovoltaic string can be quickly reduced to a safe voltage range acceptable to the human body, without affecting the timely adoption of measures to deal with emergencies.

[0040] According to some embodiments of the present invention, a photovoltaic string is provided, referring to Figure 6 The switch module 223 includes a driving module 10 and a first MOS tube Q1. The output end of the control module 222 is connected to the input end of the driving module 10. The output end of the driving module 10 is connected to the first input end of the first MOS tube Q1. The inter-board connecting line 101 is connected to the first output end of the first MOS tube Q1 and the second output end of the first MOS tube Q1 to form a DC circuit.

[0041] Optionally, the first MOS tube Q1 can be an NMOS tube, the output end of the driving module 10 is connected to the first input end of the first MOS tube Q1, that is, the gate of the NMOS tube, and the inter-board connecting line 101 is connected to the first output end of the first MOS tube Q1, that is, the source of the NMOS tube, and the second output end of the first MOS tube Q1, that is, the drain of the NMOS tube to form a DC circuit.

[0042] It should be noted that the carrier extraction module 210 is used to extract the AC signal from the inter-board connection line 101 and supply power to the power supply module 221. The power supply module 221 is connected to the control module 222. The power supply module 221 is used to provide a stable voltage that meets its requirements to the control module 222 to ensure that the control module 222 can obtain the required electrical energy. The control module 222 is connected to the drive module 10, and the drive module 10 is used to control the conduction and cutoff of the first MOS tube Q1; when the first MOS tube Q1 is turned on, the inter-board connection line 101 is connected to the first output end of the first MOS tube Q1 and the second output end of the first MOS tube Q1 to form a DC circuit conduction; when the first MOS tube Q1 is turned off, the inter-board connection line 101 is connected to the first output end of the first MOS tube Q1 and the second output end of the first MOS tube Q1 to form a DC circuit disconnection.

[0043] It can be understood that a driving module 10 is arranged between the control module 222 and the first MOS tube Q1. On the one hand, the driving module 10 can effectively increase the driving current of the MOS tube, ensure that the MOS tube can be quickly and reliably shut down, and protect the MOS tube; on the other hand, the driving module 10 has overcurrent, overvoltage and other protection functions, which can protect the MOS tube from damage under abnormal circumstances.

[0044] According to a photovoltaic string provided by some embodiments of the present invention, when the output end of the driving module 10 outputs a high level, the DC circuit formed by connecting the inter-board connecting line 101 with the first output end of the first MOS tube Q1 and the second output end of the first MOS tube Q1 is turned on.

[0045] It should be noted that when the output end of the driving module 10 outputs a high level, the first MOS transistor Q1 is turned on, and the DC circuit formed by connecting the inter-board connecting line 101 with the first output end of the first MOS transistor Q1 and the second output end of the first MOS transistor Q1 is turned on; when the transmitter 300 is powered off, or the transmitter 300 stops sending the AC signal of the preset frequency, the carrier extraction module 210 cannot extract the AC signal from the inter-board connecting line 101, the carrier extraction module 210 cannot supply power to the power supply module 221, the control module 222 connected to the power supply module 221 stops working, the output end of the control module 222 cannot output a high level, the driving module 10 connected to the control module 222 stops working, the first MOS transistor Q1 is turned off, and the DC circuit formed by connecting the inter-board connecting line 101 with the first output end of the first MOS transistor Q1 and the second output end of the first MOS transistor Q1 is disconnected, so that the photovoltaic string is disconnected, and the voltage of the entire photovoltaic string can be quickly reduced to a safe voltage range acceptable to the human body, without affecting the timely adoption of measures to deal with emergencies.

[0046] According to some embodiments of the present invention, a photovoltaic string is provided, referring to Figure 7The carrier extraction module 210 includes a second magnetic ring 211 and a first filtering module 212 . The second magnetic ring 211 is sleeved on the inter-board connecting line 101 . The second magnetic ring 211 is connected to the input end of the first filtering module 212 . The output end of the first filtering module 212 is connected to the switch control module 220 .

[0047] It should be noted that a second magnetic ring 211 is sleeved on the inter-board connecting line 101, and the second magnetic ring 211 in the carrier extraction module 210 is used to extract an AC signal of a preset frequency from the inter-board connecting line 101. The second magnetic ring 211 is connected to the input end of the first filtering module 212, and the output end of the first filtering module 212 is connected to the switch control module 220. The first filtering module 212 is used to filter the AC signal extracted by the second magnetic ring 211, filter out high-frequency noise and interference in the signal after being suppressed by the second magnetic ring 211, and decouple energy through the filtering processing of the first filtering module 212 and supply power to the switch control module 220.

[0048] According to some embodiments of the present invention, a photovoltaic string is provided, and the carrier extraction module 210 includes a second magnetic ring 211 and a first filter module 212. The second magnetic ring 211 is sleeved on the inter-board connecting line 101, the second magnetic ring 211 is connected to the input end of the first filter module 212, the output end of the first filter module 212 is connected to the input end of the power supply module 221, the output end of the power supply module 221 is connected to the input end of the control module 222, the output end of the control module 222 is connected to the switch module 223, and the switch module 223 is connected to the inter-board connecting line 101 to form a DC circuit.

[0049] According to some embodiments of the present invention, a photovoltaic string is provided, referring to Figure 7 The carrier extraction module 210 includes a second magnetic ring 211 and a first filter module 212. The second magnetic ring 211 is sleeved on the inter-board connecting line 101. The second magnetic ring 211 is connected to the input end of the first filter module 212. The output end of the first filter module 212 is connected to the input end of the power supply module 221. The output end of the power supply module 221 is connected to the input end of the control module 222. The output end of the control module 222 is connected to the input end of the driving module 10. The output end of the driving module 10 is connected to the first input end of the first MOS tube Q1. The inter-board connecting line 101 is connected to the first output end of the first MOS tube Q1 and the second output end of the first MOS tube Q1 to form a DC circuit.

[0050] According to some embodiments of the present invention, a photovoltaic string is provided, referring to Figure 8The carrier extraction module 210 includes a first inductor L1 and a second filtering module 213 . The first inductor L1 is connected to the inter-board connecting line 101 . The first inductor L1 is connected to the input end of the second filtering module 213 . The output end of the second filtering module 213 is connected to the switch control module 220 .

[0051] The first inductor L1 in the carrier extraction module 210 is connected to the inter-board connecting line 101, and the first inductor L1 is used to extract an AC signal of a preset frequency from the inter-board connecting line 101. The first inductor L1 is connected to the input end of the second filtering module 213, and the output end of the second filtering module 213 is connected to the switch control module 220. The second filtering module 213 is used to filter the AC signal extracted by the first inductor L1. Through the filtering processing of the second filtering module 213, energy is decoupled and power is supplied to the switch control module 220.

[0052] According to some embodiments of the present invention, a photovoltaic string is provided, and the carrier extraction module 210 includes a first inductor L1 and a second filter module 213. The first inductor L1 is connected to the inter-board connection line 101, the first inductor L1 is connected to the input end of the second filter module 213, the output end of the second filter module 213 is connected to the input end of the power supply module 221, the output end of the power supply module 221 is connected to the input end of the control module 222, the output end of the control module 222 is connected to the switch module 223, and the switch module 223 is connected to the inter-board connection line 101 to form a DC circuit.

[0053] According to some embodiments of the present invention, a photovoltaic string is provided, referring to Figure 8 The carrier extraction module 210 includes a first inductor L1 and a second filtering module 213. The first inductor L1 is connected to the inter-board connecting line 101, the first inductor L1 is connected to the input end of the second filtering module 213, the output end of the second filtering module 213 is connected to the input end of the power supply module 221, the output end of the power supply module 221 is connected to the input end of the control module 222, the output end of the control module 222 is connected to the input end of the driving module 10, the output end of the driving module 10 is connected to the first input end of the first MOS tube Q1, and the inter-board connecting line 101 is connected to the first output end of the first MOS tube Q1 and the second output end of the first MOS tube Q1 to form a DC circuit.

[0054] According to a photovoltaic string provided by some embodiments of the present invention, the shutdown component 200 also includes a collection module and a second communication module, the collection module is connected to the switch control module 220, the collection module is used to collect current data of the photovoltaic component 100, the second communication module is connected to the switch control module 220, and the second communication module is used to send the current data to the transmitter 300.

[0055] It can be understood that the transmitter 300 receives the current data sent by the second communication module. For example, when the photovoltaic component 100 is poorly connected, the processing module built into the transmitter 300 will detect that the current data is lower than the preset parameters and generate a prompt message, so that maintenance personnel can quickly go to the location of a photovoltaic component 100 for inspection.

[0056] In a second aspect, an embodiment of the present invention provides a photovoltaic system, which includes an inverter, a transmitter 300 and a photovoltaic string as described in any one of the embodiments of the first aspect, wherein an output end of the inverter is connected to a power grid.

[0057] According to some embodiments of the present invention, a photovoltaic system is provided, referring to Figure 3 , also includes a host computer and a first communication module 400, the first communication module 400 is connected to the transmitter 300, and the first communication module 400 is communicatively connected to the host computer.

[0058] It should be noted that the host computer sends control instructions to the transmitter 300 through the first communication module 400 to realize the remote control of the transmitter 300. When an emergency occurs, such as a fire or other special situation, the user can use the host computer to remotely control the transmitter 300 to stop sending the AC signal of a preset frequency to the photovoltaic string through the first magnetic ring 310, so that the switch control module 220 of the shutdown component 200 in the photovoltaic string controls the DC circuit of the inter-board connecting line 101 to be disconnected, and the voltage of the entire photovoltaic string can be quickly reduced to a safe voltage range acceptable to the human body, without affecting the timely adoption of measures to deal with emergencies.

[0059] According to a photovoltaic system provided by some embodiments of the present invention, when the host computer sends a first control instruction to the transmitter 300 through the first communication module 400, the transmitter 300 is powered off.

[0060] It is understandable that when the host computer sends the first control instruction to the transmitter 300 through the first communication module 400, the transmitter 300 is powered off. When the transmitter 300 is powered off, the transmitter 300 cannot send an AC signal of a preset frequency to the photovoltaic string through the first magnetic ring 310.

[0061] According to a photovoltaic system provided by some embodiments of the present invention, when the host computer sends a second control instruction to the transmitter 300 through the first communication module 400, the transmitter 300 stops sending an alternating current signal of a preset frequency.

[0062] It should be noted that when the host computer sends a first control instruction to the transmitter 300 through the first communication module 400, the transmitter 300 is powered off, or the host computer sends a second control instruction to the transmitter 300 through the first communication module 400, the transmitter 300 stops sending the AC signal of the preset frequency, and the carrier extraction module 210 of the shutdown component 200 cannot extract the AC signal from the inter-board connecting line 101, and the carrier extraction module 210 cannot supply power to the switch control module 220, so that the switch control module 220 cannot control the DC circuit of the inter-board connecting line 101 to be turned on, so that the switch control module 220 of the shutdown component 200 in the photovoltaic string controls the DC circuit of the inter-board connecting line 101 to be disconnected, and the voltage of the entire photovoltaic string can be quickly reduced to a safe voltage range acceptable to the human body, without affecting timely measures to deal with emergencies.

[0063] According to a photovoltaic system provided by some embodiments of the present invention, the shutdown component 200 in the photovoltaic string also includes a collection module and a second communication module, the collection module is connected to the switch control module 220, the collection module is used to collect current data of the photovoltaic component 100, the second communication module is connected to the switch control module 220, the second communication module is used to send current data to the transmitter 300, the first communication module 400 is connected to the transmitter 300, and the first communication module 400 is connected to the host computer for communication.

[0064] It can be understood that the transmitter 300 receives the current data sent by the second communication module. For example, when the photovoltaic component 100 is poorly connected, the processing module built into the transmitter 300 will detect that the current data is lower than the preset parameters, and generate a prompt message and send it to the host computer through the first communication module 400, so that maintenance personnel can quickly go to the location of a photovoltaic component 100 for inspection.

[0065] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A photovoltaic string, applied to a photovoltaic system, characterized in that: The photovoltaic system includes an inverter and a transmitter; the input end of the inverter is connected to the photovoltaic string, and the output end is connected to the power grid; the photovoltaic string includes: A plurality of photovoltaic modules, two adjacent photovoltaic modules are connected in series via an inter-panel connecting line; A first magnetic ring is sleeved on a connection line between a head-end photovoltaic assembly or a terminal photovoltaic assembly in the photovoltaic string and the inverter, the transmitter is electrically connected to the first magnetic ring, and the transmitter is used to send an AC signal of a preset frequency to the photovoltaic string through the first magnetic ring; A plurality of disconnecting components are respectively arranged on the inter-board connecting lines, and the disconnecting components include a carrier extraction module and a switch control module for controlling the on and off of the DC circuit of the inter-board connecting line. The carrier extraction module is used to extract the AC power signal from the inter-board connecting line and supply power to the switch control module.

2. The photovoltaic string according to claim 1, characterized in that: The switch control module includes a power supply module, a control module and a switch module. The carrier extraction module is connected to the input end of the power supply module, the output end of the power supply module is connected to the input end of the control module, the output end of the control module is connected to the switch module, and the switch module is connected to the inter-board connecting line to form the DC circuit.

3. The photovoltaic string according to claim 2, characterized in that: The switch module includes a driving module and a first MOS tube, the output end of the control module is connected to the input end of the driving module, the output end of the driving module is connected to the first input end of the first MOS tube, and the inter-board connecting line is connected to the first output end of the first MOS tube and the second output end of the first MOS tube to form the DC circuit.

4. The photovoltaic string according to claim 1, characterized in that: The carrier extraction module includes a second magnetic ring and a first filtering module. The second magnetic ring is sleeved on the inter-board connecting line. The second magnetic ring is connected to the input end of the first filtering module. The output end of the first filtering module is connected to the switch control module.

5. The photovoltaic string according to claim 1, characterized in that: The carrier extraction module includes a first inductor and a second filtering module. The first inductor is connected to the inter-board connecting line, the first inductor is connected to the input end of the second filtering module, and the output end of the second filtering module is connected to the switch control module.

6. The photovoltaic string according to claim 1, characterized in that: When the transmitter is powered off or stops sending the AC signal of the preset frequency, the DC circuit of the inter-board connecting line is disconnected.

7. The photovoltaic string according to claim 2, characterized in that: When the output end of the control module outputs a high level, the DC circuit formed by connecting the switch module and the inter-board connecting line is turned on.

8. The photovoltaic string according to claim 3, characterized in that: When the output end of the driving module outputs a high level, the DC circuit formed by connecting the inter-board connection line with the first output end of the first MOS tube and the second output end of the first MOS tube is turned on.

9. A photovoltaic system, characterized in that: The photovoltaic system comprises an inverter, a transmitter and a photovoltaic string according to any one of claims 1 to 8, wherein an output end of the inverter is connected to a power grid.

10. The photovoltaic system according to claim 9, characterized in that: It also includes a host computer and a first communication module, wherein the first communication module is connected to the transmitter, and the first communication module is in communication connection with the host computer.

11. The photovoltaic system according to claim 10, characterized in that: When the host computer sends a first control instruction to the transmitter through the first communication module, the transmitter is powered off.

12. The photovoltaic system according to claim 10, characterized in that: When the host computer sends a second control instruction to the transmitter through the first communication module, the transmitter stops sending the alternating current signal of the preset frequency.

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