A single-string photovoltaic power generation system

Abstract

The present application discloses a single-string photovoltaic power generation system, which adopts a structure in which a photovoltaic inverter is connected to only one photovoltaic string. Since only one photovoltaic string is connected, the emergence of a power line convergence area can be avoided, thereby greatly reducing the risk of local overtemperature, thereby reducing the occurrence of safety accidents. In addition, by introducing a component monitor, it is possible to control whether each photovoltaic component is connected to a photovoltaic string or bypassed, so that when a photovoltaic component fails, the photovoltaic component can be bypassed so that the entire photovoltaic power generation system can still remain in operation, thereby greatly reducing the loss of power generation.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic power generation, in particular to a single-string photovoltaic power generation system. Background Art

[0002] Photovoltaic inverters are an indispensable component of photovoltaic power generation systems. In existing photovoltaic power generation systems, one photovoltaic inverter is usually used to connect multiple photovoltaic strings, and multiple photovoltaic strings are connected to the photovoltaic inverter in parallel. This will result in a large number of power lines being gathered in the area where multiple photovoltaic strings are connected to the photovoltaic inverter, and cable brackets and cable ducts need to be set up to centrally arrange these power lines. Under this arrangement, because a large number of power lines are concentrated, there is a risk of local temperature rise, which will cause fire hazards, and this structure that needs to be concentrated and arranged will also increase the difficulty of construction. In addition, after a photovoltaic module fails, the existing photovoltaic power generation system cannot collect effective safety protection measures and can only cut off the power to the photovoltaic power generation system, which will cause great economic losses. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes a single-string photovoltaic power generation system to solve the safety and other problems caused by the convergence of power lines.

[0004] The single-string photovoltaic power generation system according to the utility model comprises:

[0005] A photovoltaic inverter having a group of string connection terminals and an inverter output terminal group, wherein the inverter output terminal group is used to connect to a power grid;

[0006] Multiple photovoltaic panels;

[0007] A plurality of component monitors are arranged corresponding to the plurality of photovoltaic components in a one-to-one manner. The plurality of photovoltaic components are connected in series through the plurality of component monitors to form a photovoltaic string. Each component monitor is used to control the corresponding photovoltaic component to be connected to the photovoltaic string or to bypass the corresponding photovoltaic component from the photovoltaic string. The photovoltaic string is connected to the group of string connection ends.

[0008] The single-string photovoltaic power generation system according to the embodiment of the utility model has at least the following beneficial effects:

[0009] The single-string photovoltaic power generation system of the embodiment of the utility model adopts a structure in which a photovoltaic inverter is only connected to one photovoltaic string. Because only one photovoltaic string is connected, the emergence of a power line convergence area can be avoided, thereby greatly reducing the risk of local over-temperature, thereby reducing the occurrence of safety accidents. In addition, by introducing a component monitor, it is possible to control whether each photovoltaic component is connected to a photovoltaic string or bypassed, so that when a photovoltaic component fails, the photovoltaic component can be bypassed to allow the entire photovoltaic power generation system to remain in operation, thereby greatly reducing the loss of power generation. In addition, the single-string photovoltaic power generation system of the utility model is easy to standardize and modularize, thereby effectively reducing the generation cost and subsequent maintenance cost. In addition, under the framework of the single-string photovoltaic power generation system of the utility model, the connection between the photovoltaic inverter and the photovoltaic string no longer requires the provision of a large number of cable tubes and cable brackets, thereby greatly reducing the risk of fire.

[0010] According to some embodiments of the present utility model, the photovoltaic inverter includes:

[0011] The inverter body has a positive input terminal, a negative input terminal, and an AC output terminal group, wherein the AC output terminal group is used to connect to a power grid;

[0012] String positive terminal;

[0013] A string negative terminal connected to the negative input terminal of the inverter; the string positive terminal and the string negative terminal are used together to connect the photovoltaic string;

[0014] A string switch unit, comprising a first connection end, a second connection end, a third connection end, a first drive device and a second drive device, wherein the first connection end and the second connection end constitute a first group of connection contacts, the first connection end and the third connection end constitute a second group of connection contacts, the first connection end is connected to the positive terminal of the string, and the second connection end is connected to the positive input end; the first drive device is used to connect the first group of connection contacts and disconnect the second group of connection contacts after being energized, and the second drive device is used to disconnect the first group of connection contacts and connect the second group of connection contacts after being energized;

[0015] The string switch tube has a controlled end, a first switch connection end and a second switch connection end; the first switch connection end is connected to the first connection end; the second switch connection end is connected to the second connection end;

[0016] A string control unit is connected to the first drive device, the second drive device and the controlled end respectively, and is used to change the power-on state of the first drive device and the power-on state of the second drive device, and to control the controlled end to adjust the on-off state between the first switch connection end and the second switch connection end.

[0017] According to some embodiments of the utility model, the single-string photovoltaic power generation system further includes an energy storage device, which is used to store electrical energy flowing through the single-string photovoltaic power generation system and release the electrical energy stored in the energy storage device.

[0018] According to some embodiments of the present utility model, the single-string photovoltaic power generation system further includes an emergency stop device, and the negative terminal of the string is connected to the positive input end through the emergency stop device.

[0019] According to some embodiments of the present invention, the single-string photovoltaic power generation system further includes a first wireless communication module connected to the string control unit.

[0020] According to some embodiments of the present invention, the single-string photovoltaic power generation system further includes a positioning module connected to the string control unit.

[0021] According to some embodiments of the present invention, the component monitor includes:

[0022] A component switch unit, comprising a fourth connection terminal, a fifth connection terminal, a sixth connection terminal, a third drive device and a fourth drive device, wherein the fourth connection terminal and the fifth connection terminal constitute a third group of connection contacts, the fourth connection terminal and the sixth connection terminal constitute a fourth group of connection contacts, the fifth connection terminal is used to connect the first output terminal of the photovoltaic component, and the sixth connection terminal is used to connect the second output terminal of the photovoltaic component; the third drive device is used to connect the third group of connection contacts and disconnect the fourth group of connection contacts after being powered on, and the fourth drive device is used to disconnect the third group of connection contacts and connect the fourth group of connection contacts after being powered on;

[0023] The component control unit is used to change the power-on state of the third driving device and the power-on state of the fourth driving device.

[0024] According to some embodiments of the present invention, the component monitor further includes a second wireless communication module connected to the component control unit.

[0025] According to some embodiments of the present invention, the component control unit obtains working power from the photovoltaic component.

[0026] According to some embodiments of the present invention, the component monitor further includes a first voltage sensor connected to the component control unit, and the first voltage sensor is connected between the first output terminal and the second output terminal.

[0027] According to some embodiments of the present invention, the component monitor also includes a component current sensor connected to the component control unit, and the component current sensor is connected in series between the fifth connection terminal and the first output terminal; the component monitor also includes a second voltage sensor connected to the component control unit, and the second voltage sensor is connected between the sixth connection terminal and the fourth connection terminal.

[0028] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0030] Figure 1 This is a system diagram of a single-string photovoltaic power generation system according to an embodiment of the utility model;

[0031] Figure 2 A schematic circuit diagram of a photovoltaic inverter according to an embodiment of the present utility model;

[0032] Figure 3 A system diagram of a photovoltaic inverter according to an embodiment of the utility model;

[0033] Figure 4 A schematic circuit diagram of a component monitor according to an embodiment of the present utility model;

[0034] Figure 5 This is a system diagram of a component monitor according to an embodiment of the present invention.

[0035] Reference numerals:

[0036] Photovoltaic inverter 100, inverter body 110, inverter unit 111, AC switch unit 112, input filter unit 113, output filter unit 114, string switch unit 121, string switch tube 122, string control unit 123, emergency stop device 130, first wireless communication module 140, positioning module 150, energy storage device 160;

[0037] The component monitor 200, the component switch unit 210, the component control unit 220, the second wireless communication module 230, the first voltage sensor 240, the component current sensor 250, and the second voltage sensor 260;

[0038] Photovoltaic module 300. DETAILED DESCRIPTION

[0039] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0040] In the description of the present utility model, if there is a description of first, second, etc., it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0041] In the description of the present invention, it should be understood that the descriptions involving orientation, such as the orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0042] In the description of the present invention, it should be noted that, 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 in combination with the specific content of the technical solution.

[0043] The technical solution of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described below are only part of the embodiments of the present utility model, not all of the embodiments.

[0044] See also Figure 1 , Figure 1 1 is a system diagram of a single-string photovoltaic power generation system according to an embodiment of the present utility model, wherein the single-string photovoltaic power generation system comprises: a photovoltaic inverter 100, a plurality of photovoltaic modules 300 and a plurality of module monitors 200;

[0045] The photovoltaic inverter 100 has a group of string connection terminals and an inverter output terminal group, and the inverter output terminal group is used to connect to the power grid;

[0046] A plurality of photovoltaic modules 300;

[0047] A plurality of component monitors 200 are arranged corresponding to a plurality of photovoltaic components 300 in a one-to-one manner. The plurality of photovoltaic components 300 are connected in series through the plurality of component monitors 200 to form a photovoltaic string. Each component monitor 200 is used to control the corresponding photovoltaic component 300 to be connected to the photovoltaic string or to bypass the corresponding photovoltaic component 300 from the photovoltaic string; the photovoltaic string is connected to a group of string connection ends.

[0048] refer to Figures 1 to 5 After the photovoltaic modules 300 are connected to the module monitor 200, they are no longer directly connected to form a photovoltaic string through adjacent photovoltaic modules 300, but are connected in series through the module monitor 200 corresponding to each photovoltaic module 300 to form a string, so that the photovoltaic modules 300 can be connected to the photovoltaic string and the bypass control in the photovoltaic string can be realized through the module monitor 200. Therefore, when a photovoltaic module 300 fails, the photovoltaic module 300 can be bypassed to keep the entire photovoltaic power generation system running, thereby greatly reducing the loss of power generation.

[0049] The single-string photovoltaic power generation system of the embodiment of the utility model also adopts a structure in which a photovoltaic inverter 100 is only connected to one photovoltaic string. Because only one photovoltaic string is connected, the emergence of a power line convergence area can be avoided, thereby greatly reducing the risk of local excessive temperature, thereby reducing the occurrence of safety accidents. At the same time, because there is no power line convergence area, auxiliary structures for power line layout such as cable brackets and cable ducts can be cancelled, which greatly reduces the difficulty of installation and saves a certain amount of installation cost. In addition, the single-string photovoltaic power generation system of the utility model is easy to standardize and modularize, thereby effectively reducing the generation cost and later maintenance cost. In addition, under the framework of the single-string photovoltaic power generation system of the utility model, the connection between the photovoltaic inverter 100 and the photovoltaic string no longer needs to be provided with a large number of cable tubes and cable brackets, thereby greatly reducing the risk of fire.

[0050] In addition, in the embodiment of the utility model, a photovoltaic inverter 100 only regulates and controls one photovoltaic string, which can achieve optimal control, so that the photovoltaic string is at the best power generation efficiency. In addition, because the number of photovoltaic strings connected to a single photovoltaic inverter 100 is reduced, the heat generated by the photovoltaic inverter 100 is greatly reduced, and there is no need to set up a fan for heat dissipation. While increasing the service life of the inverter, the overall volume of the photovoltaic inverter 100 can be reduced, and the layout of the photovoltaic inverter 100 is more flexible.

[0051] refer to Figure 2 , Figure 3In some embodiments, the photovoltaic inverter 100 includes an inverter body 110, a string positive terminal, a string negative terminal, a string switch unit 121, a string switch tube 122 and a string control unit 123;

[0052] The inverter body 110 has a positive input terminal, a negative input terminal, and an AC output terminal group, and the AC output terminal group is used to connect to the power grid;

[0053] The negative terminal of the string is connected to the negative input terminal of the inverter; the positive terminal of the string and the negative terminal of the string are used together to connect the photovoltaic strings;

[0054] The string switch unit 121 has a first connection end, a second connection end, a third connection end, a first drive device and a second drive device. The first connection end and the second connection end constitute a first group of connection contacts, the first connection end and the third connection end constitute a second group of connection contacts, the first connection end is connected to the positive terminal of the string, and the second connection end is connected to the positive input end; the first drive device is used to connect the first group of connection contacts and disconnect the second group of connection contacts after power is supplied, and the second drive device is used to disconnect the first group of connection contacts and connect the second group of connection contacts after power is supplied;

[0055] The string switch tube 122 has a controlled end, a first switch connection end, and a second switch connection end; the first switch connection end is connected to the first connection end; the second switch connection end is connected to the second connection end;

[0056] The string control unit 123 is connected to the first driving device, the second driving device and the controlled end respectively, and is used to change the power-on state of the first driving device and the power-on state of the second driving device, and control the controlled end to adjust the on-off state between the first switch connection end and the second switch connection end.

[0057] The string switch tube 122 has good voltage and current impact resistance. When the photovoltaic string needs to be disconnected, the first group of connection contacts of the string switch unit 121 is bypassed by first controlling the string switch tube 122, and then the first group of connection contacts of the string switch unit 121 is disconnected and the second group of connection contacts are closed. At this time, the voltage and current impact that the string switch unit 121 needs to face will be much smaller, so that the low-cost string switch unit 121 can be selected. After the string switch unit 121 completes the adjustment of the connection contacts, the power supply of the string switch unit 121 can be disconnected, and then the string switch tube 122 is controlled to disconnect, that is, the circuit disconnection of the entire photovoltaic string is completed. And after the photovoltaic string circuit is disconnected, because the circuit is disconnected, the component monitor 200 is disconnected and does not need to face high voltage and large current, thereby reducing the cost of the component switch unit 210, that is, the technical solution in the embodiment of the utility model can be implemented at a very low cost.

[0058] In addition, the string switch unit 121 adopts a device with a dual-drive structure, so that it can only provide short-term power supply when the switch action needs to be driven, and stop supplying power after the action is completed, which can greatly save energy.

[0059] refer to Figure 2 , Figure 3 In some embodiments, the string switch tube 122 uses an IGBT. The gate of the IGBT is connected to the string control unit 123, and the source and drain are connected to the first connection terminal and the second connection terminal respectively. When the string control unit 123 outputs a control voltage to the gate of the IGBT, the IGBT is turned on, so that the source and drain are connected, and the first group of connection contacts are bypassed. At this time, the string control unit 123 can switch the power-on state of the control coil, so that the first group of connection contacts are disconnected and the second group of connection contacts are connected.

[0060] refer to Figure 2 , in some embodiments, the inverter body 110 includes an inverter unit 111 and an AC switch unit 112;

[0061] The inverter unit 111 has a first DC input terminal, a second DC input terminal, and an inverter AC output terminal group, wherein the first DC input terminal is connected to the second connection terminal, and the second DC input terminal is connected to the negative terminal DC- of the string;

[0062] The AC switch unit 112 has a switch AC input terminal group and a switch AC output terminal group. The switch AC input terminal is connected to the inverter AC input terminal group. The switch AC output terminal group is used to output the inverted AC power.

[0063] The inverter unit 111 can realize the inversion of the DC power input by the photovoltaic string, so that the photovoltaic inverter 100 can be connected to the mains. The AC switch unit 112 can realize the disconnection of the AC circuit of the single-string photovoltaic power generation system, which can improve the safety and convenience of use.

[0064] refer to Figure 2 In some embodiments, the single-string photovoltaic power generation system further includes an input filter unit 113, which is used to filter the direct current input to the inverter unit 111. The input filter unit 113 can filter the direct current side and improve the quality of power conversion.

[0065] refer to Figure 2 In some embodiments, the single-string photovoltaic power generation system further includes an output filter unit 114, which is used to filter the AC power output by the inverter unit 111. The output filter unit 114 can filter the AC side and improve the quality of power output.

[0066] refer to Figure 3In some embodiments, the single-string photovoltaic power generation system further includes an energy storage device 160, which is used to store the electric energy flowing through the single-string photovoltaic power generation system and release the electric energy stored in the energy storage device 160. The energy storage device 160 can store the surplus electric energy generated by the photovoltaic string, and can release the stored electric energy to the grid for power supply when the output power of the photovoltaic inverter 100 is insufficient.

[0067] refer to Figure 2 In some embodiments, the single-string photovoltaic power generation system also includes an emergency stop device 130, and the negative terminal of the string is connected to the positive input terminal through the emergency stop device 130. The emergency stop device 130 can realize the emergency disconnection of the photovoltaic string, which is suitable for emergency protection directly and quickly locally in an emergency. The emergency stop device 130 can use an emergency stop switch or other switch components with a manual disconnection function. It should be noted that after the emergency stop device 130 performs an emergency operation, the AC switch unit 112, the string switch unit 121, and the component switch unit 210 can be disconnected with one button to eliminate the risks brought by high voltage.

[0068] refer to Figure 3 In some embodiments, the single-string photovoltaic power generation system further includes a first wireless communication module 140 connected to the string control unit 123. The photovoltaic inverter 100 needs to interact with the photovoltaic module 300 to obtain the operation data of each photovoltaic module 300 in the photovoltaic string. Compared with the wired communication module, the first wireless communication module 140 can reduce the complexity of wiring to a certain extent and reduce the construction labor cost. In addition, after the photovoltaic inverter 100 cuts off the photovoltaic string, carrier communication (a traditional solution that does not require additional wiring) cannot be used, and the use of the first wireless communication module 140 can avoid this problem.

[0069] refer to Figure 3 In some embodiments, the single-string photovoltaic power generation system further includes a positioning module 150 connected to the string control unit 123. The positioning module 150 can realize real-time positioning of the single-string photovoltaic power generation system. On the one hand, it can facilitate the subsequent real-time monitoring of the operation of the single-string photovoltaic power generation system, and on the other hand, it can also complete the requirements of asset management based on the positioning module 150. In some embodiments, the positioning module 150 can adopt a Beidou positioning module, a GPS positioning module or other single-core positioning modules, and a fusion positioning module.

[0070] In some embodiments, the single-string photovoltaic power generation system further includes a power storage unit, and the string control unit 123 is used to obtain power supply from the power storage unit and / or the inverter AC output terminal group of the inverter unit 111 and / or the first DC input terminal and the second DC input terminal of the inverter unit 111. Redundant power supply using the power storage unit, the AC side, and the DC side can ensure the stability of the operation of the string control unit 123 to a great extent, and even if the DC side and the AC side are powered off at the same time, it still has the working ability and completes the rapid disconnection of the photovoltaic string.

[0071] refer to Figure 4 , Figure 5 ,In some embodiments, the component monitor 200 includes a component switch unit 210 and a component control unit 220;

[0072] The assembly switch unit 210 has a fourth connection terminal, a fifth connection terminal, a sixth connection terminal, a third driving device and a fourth driving device. The fourth connection terminal and the fifth connection terminal constitute a third group of connection contacts, the fourth connection terminal and the sixth connection terminal constitute a fourth group of connection contacts, the fifth connection terminal is used to connect the first output terminal of the photovoltaic assembly 300, and the sixth connection terminal is used to connect the second output terminal of the photovoltaic assembly 300; the third driving device is used to connect the third group of connection contacts and disconnect the fourth group of connection contacts after being powered on, and the fourth driving device is used to disconnect the third group of connection contacts and connect the fourth group of connection contacts after being powered on;

[0073] The component control unit 220 is used to change the power-on state of the third driving device and the power-on state of the fourth driving device.

[0074] When the photovoltaic system is put into use, the third group of connection contacts is in a closed state, and the fourth group of connection contacts is in an open state. At this time, the photovoltaic assembly 300 connected to the photovoltaic monitor is connected to the photovoltaic string through the photovoltaic monitor. When all photovoltaic assemblies 300 in the photovoltaic string are working normally, the photovoltaic string is in a normal working state. When a photovoltaic assembly 300 connected to the assembly monitor 200 has a problem, in order to ensure that the photovoltaic string continues to generate electricity, at this time, the assembly control unit 220 can control the fourth drive device of the assembly switch unit 210 to disconnect the third group of connection contacts and connect the fourth group of connection contacts, so that the photovoltaic assembly 300 is separated from the photovoltaic string and bypassed by the assembly switch unit 210, so that the remaining photovoltaic assemblies 300 in a normal state can continue to form a photovoltaic string to generate electricity. In addition, because the assembly switch unit 210 adopts a dual control coil control method, it can only be powered on for a short time when the connection contacts need to be switched. Whether the photovoltaic assembly 300 is normally connected or bypassed, it is not necessary to continuously supply power to maintain the contact action.

[0075] In this embodiment, the component monitor can bypass the photovoltaic component 300 through the component switch unit 210, and can also connect the photovoltaic component 300 to the photovoltaic string, so that when the photovoltaic component 300 fails and the diode is turned on, the string current that originally flows through the diode is transferred to the component switch unit 210, and the component switch unit 210 itself no longer uses the diode as a bypass device, so that the heating problem caused by the diode can be effectively solved. At the same time, because double coil control is adopted, the third drive device or the fourth drive device can be energized when only the third group of connection contacts and the fourth group of connection contacts need to be switched, that is, power supply is only required during switching, and when the photovoltaic component 300 is normally connected or the photovoltaic component 300 is bypassed, no electric energy is wasted, so that energy can be saved to a great extent. In addition, when the photovoltaic component 300 has other faults and needs to be removed from the photovoltaic string, the component monitor 200 of the embodiment of the utility model can also be used to complete the bypass to ensure that the remaining photovoltaic components 300 in a normal state can continue to generate electricity.

[0076] refer to Figure 4 , Figure 5 In some embodiments, both the string switch unit 121 and the component switch unit 210 use a pulse-triggered control switch. A pulse-triggered control switch having two control coils is selected, and the pulse-triggered control switch switches to different connection contacts only when different coils are energized, which can be well applied to the single-string photovoltaic power generation system of the embodiment of the utility model. It should be noted that the component switch unit 210 can use a common single-coil driven conversion switch and relay according to actual needs, and can use a normally closed contact to connect the photovoltaic component 300 to the photovoltaic string, and a normally open contact for bypass operation.

[0077] refer to Figure 4 , Figure 5 In some embodiments, the component monitor 200 further includes a second wireless communication module 230 connected to the component control unit 220. The component monitor 200 usually needs to exchange data with the photovoltaic inverter 100. Compared with the wired communication module, the second wireless communication module 230 can reduce the complexity of wiring to a certain extent and reduce the construction labor cost. In addition, under normal circumstances, the component monitor 200 will consider taking power from the corresponding connected photovoltaic component 300, and at the same time, in order to reduce the cost of the component switch unit 210 (i.e., select ordinary products instead of high-voltage resistant products), when bypassing, the photovoltaic string will be cut off through the photovoltaic inverter 100 end first, and then the photovoltaic component 300 will be cut off. At this time, carrier communication (a traditional solution without additional wiring) cannot be used, and the use of the second wireless communication module 230 can avoid this problem.

[0078] In some embodiments, the component control unit 220 obtains working power from the photovoltaic component 300. The component control unit 220 directly obtains power from the photovoltaic component 300, so after the photovoltaic component 300 is bypassed by the diode, the working power will be lost; the component control unit 220 can communicate wirelessly with the photovoltaic inverter 100 side through the second wireless communication module 230. When the working power is lost, it will no longer be able to communicate with the photovoltaic inverter 100 side. At this time, the photovoltaic inverter 100 can determine that the photovoltaic component 300 is faulty. At this time, the photovoltaic inverter 100 will disconnect the circuit in the photovoltaic string where the photovoltaic component 300 is located, so that the entire photovoltaic string is in an open circuit state, and the bypass diode of the faulty photovoltaic component 300 will be restored to the cut-off state. At this time, the photovoltaic component 300 will not be bypassed by the diode and can emit weak electricity again, but because it does not need to carry a large load, it can have a higher output voltage. The component control unit 220 can restart working under the drive of this voltage. After the photovoltaic inverter 100 re-establishes a wireless connection with the component control unit 220, it can send a component bypass instruction to the component control unit 220. At this time, the component control unit 220 will control the component switch unit 210 to bypass the photovoltaic component 300. After the photovoltaic component 300 is bypassed, the photovoltaic component 300 will remain in an open circuit state, so that the component control unit 220 can be continuously powered, so that the component switch unit 210 can always remain in the bypass state.

[0079] refer to Figure 4 , Figure 5 In some embodiments, the component monitor 200 further includes a first voltage sensor 240 connected to the component control unit 220, and the first voltage sensor 240 is connected between the first output terminal and the second output terminal. The first voltage sensor 240 can detect the voltage of the photovoltaic component 300, so that the component control unit 220 can monitor the voltage data of the photovoltaic component 300, and each monitor in the photovoltaic string can be transmitted to the photovoltaic inverter 100 in one step through the second wireless communication module 230, so that the photovoltaic inverter 100 can monitor the voltage of all photovoltaic components 300 in the entire string in real time.

[0080] refer to Figure 4 , Figure 5In some embodiments, the component monitor 200 further includes a component current sensor 250 connected to the component control unit 220, and the component current sensor 250 is connected in series between the fifth connection terminal and the first output terminal; the component monitor 200 further includes a second voltage sensor 260 connected to the component control unit 220, and the second voltage sensor 260 is connected between the sixth connection terminal and the fourth connection terminal. When the photovoltaic component 300 is normally connected to the string, the component current sensor 250 can detect the current of the photovoltaic component 300. When the component switch unit 210 bypasses the photovoltaic component 300, the component current sensor 250 will be in an open circuit state, so that the current cannot be detected. By using this characteristic, it can be determined whether the component switch unit 210 has completed the bypass successfully. When the photovoltaic module 300 is normally connected to the string, the second voltage sensor 260 can detect the voltage of the photovoltaic module 300. When the module switch unit 210 bypasses the photovoltaic module 300, the second voltage sensor 260 will be in a short-circuit state, so that the voltage cannot be detected. By using this characteristic, it can be determined whether the module switch unit 210 has successfully completed the bypass, and the closed-loop feedback of the bypass control can be achieved. After the second voltage sensor 260 and the module current sensor 250 are combined, it can be realized to detect whether the fourth group of connection contacts are closed and whether the third group of connection contacts are disconnected, so as to achieve the closed-loop feedback of the bypass control.

[0081] In addition, in the embodiment of the present application, the AC switch unit 112, the string switch unit 121, and the component switch unit 210 can be linked to provide a basis for realizing one-button start and stop.

[0082] The embodiments of the present invention are described in detail above in conjunction with 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 relevant technical field without departing from the purpose of the present invention.

Claims

1. A single-string photovoltaic power generation system, characterized in that: include: A photovoltaic inverter having a group of string connection terminals and an inverter output terminal group, wherein the inverter output terminal group is used to connect to a power grid; Multiple photovoltaic panels; A plurality of component monitors are arranged corresponding to the plurality of photovoltaic components one by one, and the plurality of photovoltaic components are connected in series through the plurality of component monitors to form a photovoltaic string, and each component monitor is used to control the corresponding photovoltaic component to be connected to the photovoltaic string or to bypass the corresponding photovoltaic component from the photovoltaic string; the photovoltaic string is connected to the group of string connection terminals; The photovoltaic inverter comprises: The inverter body has a positive input terminal, a negative input terminal, and an AC output terminal group, wherein the AC output terminal group is used to connect to a power grid; String positive terminal; A string negative terminal connected to the negative input terminal of the inverter; the string positive terminal and the string negative terminal are used together to connect the photovoltaic string; A string switch unit, comprising a first connection end, a second connection end, a third connection end, a first drive device and a second drive device, wherein the first connection end and the second connection end constitute a first group of connection contacts, the first connection end and the third connection end constitute a second group of connection contacts, the first connection end is connected to the positive terminal of the string, and the second connection end is connected to the positive input end; the first drive device is used to connect the first group of connection contacts and disconnect the second group of connection contacts after being energized, and the second drive device is used to disconnect the first group of connection contacts and connect the second group of connection contacts after being energized; The string switch tube has a controlled end, a first switch connection end and a second switch connection end; the first switch connection end is connected to the first connection end; the second switch connection end is connected to the second connection end; a string control unit, connected to the first drive device, the second drive device and the controlled end respectively, for changing the power-on state of the first drive device and the power-on state of the second drive device, and controlling the controlled end to adjust the on-off state between the first switch connection end and the second switch connection end; The component monitor includes: A component switch unit, comprising a fourth connection terminal, a fifth connection terminal, a sixth connection terminal, a third drive device and a fourth drive device, wherein the fourth connection terminal and the fifth connection terminal constitute a third group of connection contacts, the fourth connection terminal and the sixth connection terminal constitute a fourth group of connection contacts, the fifth connection terminal is used to connect the first output terminal of the photovoltaic component, and the sixth connection terminal is used to connect the second output terminal of the photovoltaic component; the third drive device is used to connect the third group of connection contacts and disconnect the fourth group of connection contacts after being powered on, and the fourth drive device is used to disconnect the third group of connection contacts and connect the fourth group of connection contacts after being powered on; The component control unit is used to change the power-on state of the third driving device and the power-on state of the fourth driving device.

2. The single-string photovoltaic power generation system according to claim 1, characterized in that: The single-string photovoltaic power generation system further includes a first wireless communication module connected to the string control unit.

3. The single-string photovoltaic power generation system according to claim 1, characterized in that: The single-string photovoltaic power generation system further includes a positioning module connected to the string control unit.

4. The single-string photovoltaic power generation system according to claim 1, characterized in that: The single-string photovoltaic power generation system further includes an energy storage device, which is used to store the electrical energy flowing through the single-string photovoltaic power generation system and release the electrical energy stored in the energy storage device.

5. The single-string photovoltaic power generation system according to claim 1, characterized in that: The component monitor also includes a second wireless communication module connected to the component control unit.

6. The single-string photovoltaic power generation system according to claim 5, characterized in that: The component control unit obtains working power from the photovoltaic component.

7. The single-string photovoltaic power generation system according to claim 1, characterized in that: The component monitor further includes a first voltage sensor connected to the component control unit, wherein the first voltage sensor is connected between the first output terminal and the second output terminal.

8. The single-string photovoltaic power generation system according to claim 1, characterized in that: The component monitor further includes a component current sensor connected to the component control unit, wherein the component current sensor is connected in series between the fifth connection terminal and the first output terminal; the component monitor further includes a second voltage sensor connected to the component control unit, wherein the second voltage sensor is connected between the sixth connection terminal and the fourth connection terminal.

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