String monitor and photovoltaic monitoring system

Abstract

The utility model discloses a string monitor and a photovoltaic monitoring system, the string monitor is additionally arranged between a photovoltaic string and a photovoltaic inverter, so that the transformation of the existing photovoltaic power generation system can be realized, and the embodiment of the utility model can realize bypass of a string switch unit by using a switch tube, so that the utilization rate of the string switch unit is improved. When the string switch unit is cut off, the string switch unit does not need to be impacted by large current and high voltage, so that the string switch unit can select a switching device which is small in size, low in cost and high in reliability, the switching tube is high in current resistance and voltage resistance, the requirement for photovoltaic string breaking is met, and the switching tube is small in size, low in cost and high in reliability as well. And the production cost of the string monitor is greatly reduced. Moreover, the current change of the photovoltaic string can be detected through the string current sensor, and a feedback basis is provided for subsequent safety control of the photovoltaic string.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic power generation, and particularly relates to a string monitor and a photovoltaic monitoring system. Background Art

[0002] At present, the shutdown of photovoltaic strings in a photovoltaic power generation system is completed by a photovoltaic inverter. However, during the power generation process of the photovoltaic power generation system, the photovoltaic strings have direct current with large current and high voltage. In order to be able to shut down the photovoltaic strings with large current and high voltage in case of a fault, the string control switch in the existing photovoltaic inverter must have the ability to withstand large current and high voltage, resulting in a large volume, high cost, short service life, high power consumption, etc. of the photovoltaic inverter. At present, in order to save costs, some photovoltaic power generation systems on the market do not use high-performance photovoltaic inverters or use photovoltaic inverters with poor performance, and such products have great potential safety hazards. Therefore, how to achieve safe control of photovoltaic strings at a low cost has become an urgent problem to be solved at present. Summary of the Utility Model

[0003] The utility model aims to at least solve one of the technical problems existing in the prior art. For this purpose, the utility model provides a string monitor, which can achieve safe control of photovoltaic strings at a low cost.

[0004] An embodiment of the utility model also provides a photovoltaic string monitoring system.

[0005] The string monitor according to the first aspect embodiment of the utility model includes:

[0006] A string switch unit having a first connection end, a second connection end, and a third connection end. A first set of string connection contacts is formed between the first connection end and the second connection end, and a second set of string connection contacts is formed between the first connection end and the third connection end. The string switch unit is connected between the photovoltaic string and the photovoltaic inverter through the first set of string connection contacts;

[0007] A switching tube having 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;

[0008] A string current sensor for detecting the string current flowing through the string switch unit;

[0009] The string control unit is respectively connected to the string switch unit, the controlled end, and the string current sensor, and is used to adjust the on / off states of the first set of string connection contacts and the second set of string connection contacts, and control the controlled end to adjust the on / off state between the first switch connection end and the second switch connection end;

[0010] The power supply module is used to provide power for the string control unit.

[0011] The string monitor according to the embodiment of the present invention has at least the following beneficial effects:

[0012] By adding a string monitor between the photovoltaic string and the photovoltaic inverter, the transformation of the existing photovoltaic power generation system can be realized. And in the embodiment of the present invention, the string switch unit can be bypassed by using a switching tube, so that when the string switch unit is cut off, it does not need to withstand the impact of large current and high voltage. Therefore, the string switch unit can select switch devices with small volume, low cost and high reliability. And the switching tube has strong current-carrying and voltage-resistant capabilities, meeting the requirements of photovoltaic string breaking. Moreover, the switching tube also has small volume, low cost and high reliability, greatly reducing the production cost of the string monitor. And, the change of the photovoltaic string current can be detected through the string current sensor, providing a feedback basis for subsequent safety control of the photovoltaic string.

[0013] According to some embodiments of the present invention, the power supply module includes a voltage conversion module, and the voltage conversion module obtains the input power from the output side of the photovoltaic string, converts it, and supplies power to the string control unit.

[0014] According to some embodiments of the present invention, the string monitor further includes a string wireless communication module connected to the string control unit.

[0015] According to some embodiments of the present invention, the string switch unit adopts a dual-drive device switch, and the dual-drive device switch is internally provided with a first drive device and a second drive device both connected to the string control unit. The first drive device is used to connect the first set of string connection contacts and disconnect the second set of string connection contacts after being powered on. The second drive device is used to disconnect the first set of string connection contacts and connect the second set of string connection contacts after being powered on.

[0016] According to some embodiments of the present invention, the dual-drive device switch adopts a pulse-triggered control switch, and the pulse-triggered control switch is internally provided with a first control coil serving as the first drive device and a second control coil serving as the second drive device.

[0017] According to some embodiments of the present utility model, the string switch unit adopts a single-coil control switch, and the single-coil control switch is internally provided with a third control coil, and the third control coil is used to adjust the on-off state of the first set of string connection contacts and the second set of string connection contacts after being powered on, wherein the first set of string connection contacts is a normally closed contact.

[0018] According to some embodiments of the present utility model, the switching tube adopts an IGBT.

[0019] According to some embodiments of the present utility model, the string monitor further includes a string voltage sensor connected to the string control unit, and the string voltage sensor is used to detect the DC voltage of the photovoltaic string.

[0020] According to some embodiments of the present utility model, the string monitor further includes an emergency stop device, and the emergency stop device is used to cut off the connection between the photovoltaic string and the photovoltaic inverter.

[0021] According to some embodiments of the present utility model, the string monitor further includes a positioning module connected to the string control unit.

[0022] According to the photovoltaic monitoring system of the second aspect embodiment of the present utility model, it includes the string monitor as described above and a photovoltaic module monitor corresponding to each photovoltaic module in the photovoltaic string; the photovoltaic module monitor includes a module control unit, a module switch unit, a module wireless communication module, and a first voltage sensor connected to the module control unit; the first voltage sensor is used to collect the module voltage data corresponding to the photovoltaic module; the module switch unit is used to connect the photovoltaic module to the photovoltaic string or bypass the photovoltaic module from the photovoltaic string; each of the module wireless communication modules is used to perform wireless communication with the string wireless communication module.

[0023] The photovoltaic monitoring system according to the embodiments of the present utility model has at least the following beneficial effects:

[0024] Since the photovoltaic monitoring system adopts the technical solution of the string monitor in the above embodiments, it has at least all the beneficial effects brought by the string monitor in the above embodiments, and by further providing a photovoltaic module monitor corresponding to each photovoltaic module in the photovoltaic string, it can effectively monitor each photovoltaic module, so that when a fault occurs in the photovoltaic string or any photovoltaic module, timely and effective management and control can be carried out.

[0025] The additional aspects and advantages of the present utility model will be partially given in the following description, partially will become obvious from the following description, or be understood through the practice of the present utility model. Description of the Drawings

[0026] The above and / or additional aspects and advantages of the present utility model will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, wherein:

[0027] Figure 1 is the circuit diagram of the string monitor according to the embodiment of the present utility model;

[0028] Figure 2 is the system diagram of the string monitor according to the embodiment of the present utility model;

[0029] Figure 3 is the circuit diagram of the component monitor according to the embodiment of the present utility model;

[0030] Figure 4 is the system diagram of the photovoltaic monitoring system according to the embodiment of the present utility model.

[0031] Reference numerals:

[0032] String switch unit 110, switching tube 120, string control unit 130, string current sensor 140, power supply module 150, string wireless communication module 160, emergency stop device 170, positioning module 180, string voltage sensor 190;

[0033] Component switch unit 210, component control unit 220, first voltage sensor 230, component current sensor 240, second voltage sensor 250, photovoltaic module 270. Detailed implementation manners

[0034] The embodiments of the present utility model will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary only for explaining the present utility model and should not be construed as limiting the present utility model.

[0035] In the description of the present utility model, if the first, second, etc. are described, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0036] In the description of the present utility model, it should be understood that the orientation or positional relationship involved, such as up, down, etc., indicates the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present utility model.

[0037] In the description of the present utility model, it should be noted that unless otherwise clearly defined, terms such as "arrangement", "installation", and "connection" should be understood in a broad sense, and those skilled in the relevant technical field can reasonably determine the specific meanings of the above terms in the present utility model in combination with the specific content of the technical solution.

[0038] Next, the technical solution of the present utility model will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the following described embodiments are some embodiments of the present utility model, not all embodiments.

[0039] See Figure 1 , Figure 1 is the circuit diagram of the string monitor of the embodiment of the present utility model. The string monitor includes: a string switch unit 110, a switching transistor 120, a string current sensor 140, a string control unit 130, and a power supply module 150;

[0040] The string switch unit 110 has a first connection end, a second connection end, and a third connection end. A first set of string connection contacts is formed between the first connection end and the second connection end, and a second set of string connection contacts is formed between the first connection end and the third connection end. The string switch unit 110 is connected between the photovoltaic string and the photovoltaic inverter through the first set of string connection contacts;

[0041] The switching transistor 120 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;

[0042] The string current sensor 140 is used to detect the string current flowing through the string switch unit 110;

[0043] The string control unit 130 is respectively connected to the string switch unit 110, the controlled end, and the string current sensor 140, and is used to adjust the on-off states of the first set of string connection contacts and the second set of string connection contacts, and control the controlled end to adjust the on-off state between the first switch connection end and the second switch connection end;

[0044] The power supply module 150 is used to provide power for the string control unit 130.

[0045] The above-mentioned string switch unit 110 is connected in series between the photovoltaic string and the photovoltaic inverter.

[0046] The above-mentioned string switch unit 110 can choose to cut off the positive connection wire between the photovoltaic string and the photovoltaic inverter, or can choose to cut off the negative connection wire, or can cut off both connection wires at the same time.

[0047] The switching transistor 120 of the above-mentioned string switch unit 110 can bypass the string switch. Thus, when the string switch unit 110 needs to be turned on or off, the string switch unit 110 can be bypassed by the switching transistor 120 first, and then the string switch unit 110 can be turned off or on, so as to avoid the impact of large current and high voltage on the string switch unit 110.

[0048] The above-mentioned string current sensor 140 can monitor the current of the photovoltaic string loop, enabling the string control unit 130 to determine whether there is an abnormal current in the photovoltaic string according to the string current, which is convenient for quickly cutting off the photovoltaic string when the current is abnormal. In addition, by further combining with the first voltage sensor 230 in the photovoltaic module monitor, the operating state of each photovoltaic module 270 in the photovoltaic string can be monitored.

[0049] The above-mentioned string control unit 130 can be selected according to actual computing power requirements. DSP, single-chip microcomputer, ARM, etc. can be selected. Specifically, the STM32 series processor can be selected.

[0050] The above-mentioned power supply module 150 is used to supply power to the string control unit 130. The power source of the power supply module 150 can be obtained from the photovoltaic module 270 closest to the string monitor, or from the photovoltaic inverter. The specific way of obtaining power is diverse and can be designed according to actual usage requirements.

[0051] The string monitor of the embodiment of the present utility model can transform the existing photovoltaic power generation system by adding a string monitor between the photovoltaic string and the photovoltaic inverter. And the switching transistor 120 of the embodiment of the present utility model can bypass the string switch unit 110, so that when the string switch unit 110 is cut off, it does not need to withstand the impact of large current and high voltage. Thus, the string switch unit 110 can select switch devices with small volume, low cost and high reliability. And the switching transistor 120 has strong current resistance and voltage resistance, meeting the requirements of photovoltaic string breaking. And the switching transistor 120 also has small volume, low cost and high reliability, greatly reducing the production cost of the string monitor. Moreover, the change of the photovoltaic string current can be detected through the string current sensor 140, providing a feedback basis for subsequent safety control of the photovoltaic string.

[0052] In some embodiments, the power supply module 150 includes a voltage conversion module. The voltage conversion module obtains the input power from the output side of the photovoltaic string, converts it, and then supplies power to the string control unit 130.

[0053] In this embodiment, the method of obtaining the input power from the output side of the photovoltaic string is adopted. In this way, no matter which photovoltaic module 270 has a problem, it will be due to the bypass diode in the photovoltaic module 270 (such asFigure 3 The existence of D1) can continue to form a photovoltaic string with the remaining photovoltaic modules 270 and continue to supply power, improving the stability of the power source. It should be noted that if power is taken from any one of the photovoltaic modules 270, problems such as the inability to provide a power source may easily occur when the photovoltaic module 270 is blocked or fails.

[0054] The above voltage conversion module can adopt a DC / DC voltage conversion module, preferably a product with wide voltage input. A DC transformer can also be used for bucking voltage, or a bucking circuit can be designed. The specific method to be selected can be chosen according to the actual situation.

[0055] In some embodiments, referring to Figure 2 , the string monitor further includes a string wireless communication module 160 connected to the string control unit 130.

[0056] In this embodiment, the string wireless communication module 160 can be used to wirelessly communicate with the component wireless communication module in the photovoltaic module monitor corresponding to the photovoltaic module 270.

[0057] In some embodiments, the string switch unit 110 adopts a dual-drive device switch. The dual-drive device switch is internally provided with a first drive device and a second drive device both connected to the string control unit 130. The first drive device is used to connect the first set of string connection contacts and disconnect the second set of string connection contacts after being powered on. The second drive device is used to disconnect the first set of string connection contacts and connect the second set of string connection contacts after being powered on.

[0058] The above control method of the string switch unit 110 adopting a dual-drive device can be energized for a short time only when the corresponding connection contacts need to be switched, and continuous power supply is not required to maintain the contact action.

[0059] Specifically, because the string switch unit 110 adopts drive device control, the first drive device or the second drive device can be powered on only when the states of the first set of connection contacts and the second set of connection contacts need to be switched. That is, power supply is only required during switching, so that energy can be saved to a great extent. And because dual-drive control does not require continuous power supply, the risk of misoperation due to sudden power failure caused by insufficient power supply like a common coil can be avoided, greatly increasing the reliability.

[0060] In some embodiments, the dual-drive device switch adopts a pulse trigger control switch. The pulse trigger control switch is internally provided with a first control coil serving as the first drive device and a second control coil serving as the second drive device.

[0061] In this embodiment, a pulse-triggered control switch with two control coils is selected. The pulse-triggered control switch only switches to different connection contacts when different coils are energized, and can be well applied to the photovoltaic module 270 controller of the embodiment of the present utility model.

[0062] In some embodiments, the string switch unit 110 adopts a single-coil control switch. The single-coil control switch is internally provided with a third control coil, and the third control coil is used to adjust the on-off state of the first set of string connection contacts and the second set of string connection contacts after being energized. Among them, the first set of string connection contacts is a normally closed contact.

[0063] In this embodiment, the string switch unit 110 adopts a single-coil control switch, which can also continuously connect the photovoltaic string and the photovoltaic inverter. And compared with the double-drive device switch, it can reduce costs to a certain extent. At the same time, the normally open contact and the normally closed contact of the string switch unit are always in opposite states. When the string control unit 130 controls the string switch unit 110, only the on-off of the third control coil of the string switch unit 110 needs to be controlled to realize the on-off control between the photovoltaic string and the photovoltaic inverter. It should be noted that the photovoltaic string and the photovoltaic inverter are in the on state for most of the time. Therefore, in this embodiment, using a normally closed contact to connect the photovoltaic string and the photovoltaic inverter can only perform operations when disconnection is required, thereby greatly reducing energy consumption.

[0064] In some embodiments, the switching transistor 120 adopts an IGBT.

[0065] In this embodiment, the gate of the IGBT is connected to the string control unit 130, and the source and drain are respectively connected to the first connection end and the second connection end. When the string control unit 130 outputs a control voltage to the gate of the IGBT, the IGBT is turned on, causing the source and drain to be connected, realizing the bypass of the first set of connection contacts. At this time, the string control unit 130 can switch the energization state of the control coil, causing the first set of connection contacts to be disconnected and the second set of connection contacts to be connected. And the IGBT has a low cost and is easy to obtain, which is suitable for industrial application.

[0066] In some embodiments, referring to Figure 1 、 Figure 2 , the string monitor further includes a string voltage sensor 190 connected to the string control unit 130, and the string voltage sensor 190 is used to detect the DC voltage of the photovoltaic string.

[0067] In this embodiment, the string voltage sensor 190 can be used to detect the string voltage. By detecting the change of the string voltage, it is also possible to determine to a certain extent whether there is a fault in the photovoltaic string. For example, it is possible to determine whether the photovoltaic string is disconnected, whether the current power supply voltage is stable, and whether there is a bypass of the photovoltaic module 270 in the photovoltaic string.

[0068] In some embodiments, referring to Figure 1 , the string monitor further includes an emergency stop device 170, and the emergency stop device 170 is used to cut off the connection between the photovoltaic string and the photovoltaic inverter.

[0069] In this embodiment, the emergency stop device 170700170 can achieve an emergency cut-off between the photovoltaic string and the photovoltaic inverter, which is suitable for directly performing emergency protection locally quickly in an emergency. The emergency stop device 170700170 can use an emergency stop switch or other switch components with a manual cut-off function.

[0070] The above-mentioned emergency stop device 170700170 can feedback the on / off state signal to the string control unit 130. Thus, when the emergency stop device 170 is disconnected, the string control unit 130 can send a component disconnection instruction to each photovoltaic module 270 in the photovoltaic string, so that each photovoltaic module 270 in the photovoltaic string can be completely disconnected, avoiding the existence of high voltage in the photovoltaic string and solving some safety problems caused by high voltage.

[0071] In some embodiments, referring to Figure 2 , the string monitor further includes a positioning module 180 connected to the string control unit 130.

[0072] In this embodiment, the positioning module 180 can achieve real-time positioning of the optical string monitor. On the one hand, it is convenient for subsequent real-time monitoring of the operation of the string monitor. On the other hand, it can also meet the requirements of asset management based on the positioning module 180.

[0073] The above-mentioned positioning module 180900180 can adopt a Beidou positioning module 180900180, a GPS positioning module 180900180 or other single-core positioning modules 180900180, as well as a fusion positioning module 180900180.

[0074] Referring to Figure 4, The embodiment of the present utility model also provides a photovoltaic monitoring system, which includes the above-mentioned string monitor and a photovoltaic module monitor corresponding to each photovoltaic module 270 in the photovoltaic string; the photovoltaic module monitor includes a module control unit 220, a module switch unit 210, a module wireless communication module, and a first voltage sensor 230 connected to the module control unit 220; the first voltage sensor 230 is used to collect the module voltage data of the corresponding photovoltaic module 270; the module switch unit 210 is used to connect the photovoltaic module 270 to the photovoltaic string or bypass the photovoltaic module 270 from the photovoltaic string; each module wireless communication module is used to perform wireless communication with the string wireless communication module 160.

[0075] In the photovoltaic monitoring system of the embodiment of the present utility model, since the photovoltaic monitoring system adopts the technical solution of the string monitor in the above embodiment, it has at least all the beneficial effects brought by the string monitor in the above embodiment, and by further providing a photovoltaic module monitor corresponding to each photovoltaic module 270 in the photovoltaic string, the effective monitoring of each photovoltaic module 270 can be realized, so that when a failure occurs in the photovoltaic string or any photovoltaic module 270, timely and effective management and control can be carried out.

[0076] The above-mentioned string monitor obtains the string current through the string current sensor 140, and obtains the module voltage data collected by the first voltage sensor 230 in each photovoltaic module monitor transmitted by each module wireless communication module through the string wireless communication module 160, and then can determine the operating state of each photovoltaic module 270 to complete the monitoring of each photovoltaic module 270. In addition, within a data reception period, if the voltage data sent by a certain photovoltaic monitor is not received, it can also be determined that the operation of the photovoltaic module 270 is abnormal.

[0077] In some embodiments, referring to Figure 3 , the module switch unit 210 has a fourth connection end, a fifth connection end, and a sixth connection end. A first set of module connection contacts is formed between the fourth connection end and the fifth connection end, and a second set of module connection contacts is formed between the fourth connection end and the sixth connection end. The fifth connection end and the sixth connection end are respectively connected to the two positive output ends and negative output ends of the photovoltaic module 270; the fourth connection end and the fifth connection end are used to connect the photovoltaic module 270 to the photovoltaic string.

[0078] In this embodiment, after the photovoltaic module monitor is put into use, the first group of module connection contacts are in a closed state, and the second group of module connection contacts are in an open state. At this time, the photovoltaic module 270 connected to the photovoltaic module monitor is connected to the photovoltaic string through the photovoltaic module monitor. When all photovoltaic modules 270 in the photovoltaic string are working normally, the photovoltaic string is in a normal working state. When a photovoltaic module 270 connected to the photovoltaic module monitor has a problem, in order to ensure that the photovoltaic string continues to generate electricity, at this time, the first group of module connection contacts of the module switch unit 210 can be controlled by the module control unit 220 to disconnect and the second group of module connection contacts to connect, so that the photovoltaic module 270 is separated from the photovoltaic string and bypassed by the module switch unit 210, so that the remaining photovoltaic modules 270 in a normal state can continue to form a new photovoltaic string for power generation.

[0079] In some embodiments, the component switch unit 210 can select a dual driver switch or a single coil control switch.

[0080] In this embodiment, the advantages and disadvantages of the dual drive device switch or the single coil control switch have been discussed in the above discussion of the string switch unit 110. The component switch unit 210 also has the same advantages and disadvantages, which will not be repeated here.

[0081] In some embodiments, reference Figure 3 The photovoltaic component monitor further includes a component current sensor 240 connected to the component control unit 220 , and the component current sensor 240 is connected in series between the second connection terminal and the first output terminal.

[0082] In this embodiment, when the photovoltaic component 270 is normally connected to the string, the component current sensor 240 can detect the current of the photovoltaic component 270. When the component switch unit 210 bypasses the photovoltaic component 270, the component current sensor 240 will be in an open circuit state, so that the current cannot be detected. Using this characteristic, it can be determined whether the component switch unit 210 has successfully completed the bypass. It should be noted that whether to set the component current sensor 240 needs to be adjusted according to the actual situation. If the component current sensor 240 needs to be used to review the string current detected by the string current sensor 140, it can be set. Or based on other clear requirements, under normal circumstances, it can be chosen not to set the component current sensor 240 to control the overall cost.

[0083] In some embodiments, reference Figure 3 The photovoltaic component monitor further includes a second voltage sensor 250 connected to the component control unit 220 , and the second voltage sensor 250 is connected between the sixth connection terminal and the fourth connection terminal.

[0084] In this embodiment, when the second voltage sensor 250 is normally connected to the string, it can detect the voltage of the photovoltaic module 270. When the module switch unit 210 bypasses the photovoltaic module 270, the second voltage sensor 250 will be in a short-circuit state and thus unable to detect the voltage. By using this characteristic, it can be determined whether the module switch unit 210 has successfully completed bypassing, achieving a closed-loop feedback for bypass control. After the second voltage sensor 250 and the module current sensor 240 are combined, it can detect whether the second set of module connection contacts are closed and whether the first set of module connection contacts are disconnected, achieving a closed-loop feedback for bypass control.

[0085] In some embodiments, the photovoltaic module monitor further includes a module temperature sensor (such as Figure 3 PT2 shown in the figure) connected to the module control unit 220. The temperature sensor is used to detect the module temperature inside the photovoltaic module 270. The temperature sensor can detect the temperature of the battery body inside the photovoltaic module 270, so that when the temperature exceeds the preset safe temperature threshold, an over-temperature signal can be sent to the photovoltaic inverter side in a timely manner, and further an alarm instruction can be pushed by the photovoltaic inverter to the inspection personnel to handle potential risks in a timely manner.

[0086] In some embodiments, the string monitor further includes a string temperature sensor (such as Figure 1 PT1 shown in the figure) connected to the string control unit 130. The temperature sensor is used to detect the component temperature inside the string monitor housing. The temperature sensor can detect the temperature inside the string monitor housing, so that when the temperature exceeds the preset safe temperature threshold, an alarm instruction can be pushed to the inspection personnel in a timely manner to handle potential risks in a timely manner.

[0087] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes can be made without departing from the purpose of the present invention.

Claims

1. A string monitor, characterized in that, Including: A string switch unit having a first connection end, a second connection end, and a third connection end. A first set of string connection contacts is formed between the first connection end and the second connection end, and a second set of string connection contacts is formed between the first connection end and the third connection end. The string switch unit is connected between a photovoltaic string and a photovoltaic inverter through the first set of string connection contacts; A switching tube having 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 current sensor for detecting the string current flowing through the string switch unit; A string control unit respectively connected to the string switch unit, the controlled end, and the string current sensor, for adjusting the on / off states of the first set of string connection contacts and the second set of string connection contacts, and controlling the controlled end to adjust the on / off state between the first switch connection end and the second switch connection end; A power supply module for supplying power to the string control unit.

2. The string monitor according to claim 1, wherein The power supply module includes a voltage conversion module, and the voltage conversion module obtains an input power supply from the output side of the photovoltaic string, converts it, and supplies power to the string control unit.

3. The string monitor according to claim 1, characterized in that The string monitor further includes a string wireless communication module connected to the string control unit.

4. The string monitor according to claim 1, wherein The string switch unit adopts a dual-drive device switch, and the dual-drive device switch is internally provided with a first drive device and a second drive device both connected to the string control unit. The first drive device is used to connect the first set of string connection contacts and disconnect the second set of string connection contacts after being powered on, and the second drive device is used to disconnect the first set of string connection contacts and connect the second set of string connection contacts after being powered on.

5. The string monitor according to claim 4, wherein The dual-drive device switch adopts a pulse-triggered control switch, and the pulse-triggered control switch is internally provided with a first control coil serving as the first drive device and a second control coil serving as the second drive device.

6. The string monitor according to claim 1, wherein The string switch unit adopts a single-coil control switch, and the single-coil control switch is internally provided with a third control coil. The third control coil is used to adjust the on / off states of the first set of string connection contacts and the second set of string connection contacts after being powered on, wherein the first set of string connection contacts is a normally closed contact.

7. The string monitor according to claim 1, wherein The string monitor further includes a string voltage sensor connected to the string control unit, and the string voltage sensor is used to detect the DC voltage of the photovoltaic string.

8. The string monitor according to claim 1, wherein The string monitor further includes an emergency stop device for cutting off the connection between the photovoltaic string and the photovoltaic inverter.

9. The string monitor according to claim 1, wherein The string monitor further includes a positioning module connected to the string control unit.

10. A photovoltaic monitoring system, characterized in that, It includes a string monitor as described in any one of claims 1 to 9 and a photovoltaic component monitor provided corresponding to each photovoltaic component in the photovoltaic string; the string monitor further includes a string wireless communication module; the photovoltaic component monitor includes a component control unit, a component switch unit connected to the component control unit, a component wireless communication module, and a first voltage sensor; the first voltage sensor is used to collect the component voltage data corresponding to the photovoltaic component; the component switch unit is used to connect the photovoltaic component to the photovoltaic string or bypass the photovoltaic component from the photovoltaic string; each of the component wireless communication modules is used to perform wireless communication with the string wireless communication module.

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