Photovoltaic system and its shutdown switch access identification method, operating mode setting method

Abstract

The application provides a photovoltaic system and a method for identifying access of a disconnector of the photovoltaic system and setting an operation mode, the method for identifying access of the disconnector of the photovoltaic system is as follows: voltage disturbance is performed on at least one target photovoltaic string in the photovoltaic system, the target photovoltaic string is a photovoltaic string with a string voltage lower than a safety voltage in the photovoltaic system; it is judged whether at least one string voltage greater than the safety voltage exists in the string voltages of each disturbed target photovoltaic string; if the result is yes, it is identified that the photovoltaic system is connected to the disconnector, that is, the application can utilize the characteristic that the disconnector needs to be subjected to regular voltage disturbance to keep continuous operation, identify the access state of the disconnector of the photovoltaic system by the size relationship between the disturbed photovoltaic string voltage and the safety voltage, and solve the problems of complicated operation and occupation of a large amount of manpower and material resources caused by the current mode of confirming whether the photovoltaic system is connected to the disconnector by the user on site.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of identification processing, in particular to a photovoltaic system and a method for identifying whether a shutdown device is connected to the photovoltaic system and setting an operation mode. BACKGROUND

[0002] When a photovoltaic system with a shutdown device is off-grid due to a fault, the single component is quickly short-circuited from the direct current side, and the direct current side electrical energy is quickly released through the inverter, so as to ensure that the voltage is reduced to a safe voltage within a very short time, thereby greatly enhancing the safety of the photovoltaic system.

[0003] However, since the operation control mode corresponding to the photovoltaic system with or without the shutdown device is different, it is necessary to determine whether the shutdown device is connected to the photovoltaic system before controlling the photovoltaic system to enter the corresponding mode. At present, the user needs to first confirm whether the shutdown device is connected to the photovoltaic system on site, and then manually set the operation mode in which the photovoltaic system needs to be controlled to enter, which is not only cumbersome, but also occupies a large amount of manpower and resources. SUMMARY

[0004] Therefore, the embodiments of the present application provide a photovoltaic system and a method for identifying whether a shutdown device is connected to the photovoltaic system and setting an operation mode, so as to solve the problem of cumbersome operation and occupation of a large amount of manpower and resources caused by the current way of confirming whether the shutdown device is connected to the photovoltaic system on site.

[0005] To achieve the above object, the embodiments of the present application provide the following technical solutions:

[0006] The first aspect of the embodiments of the present application discloses a method for identifying whether a shutdown device is connected to a photovoltaic system, and the method comprises the following steps:

[0007] Performing voltage disturbance on at least one target photovoltaic string in the photovoltaic system, the target photovoltaic string being a photovoltaic string with a string voltage lower than a safe voltage in the photovoltaic system;

[0008] Determining whether at least one string voltage of the string voltages of each disturbed target photovoltaic string is greater than the safe voltage;

[0009] If the determination result is yes, it is identified that the shutdown device is connected to the photovoltaic system.

[0010] Optionally, in the method for identifying whether a shutdown device is connected to a photovoltaic system, before performing voltage disturbance on at least one target photovoltaic string in the photovoltaic system, the method further comprises the following steps:

[0011] Respectively acquiring string voltages of each photovoltaic string in the photovoltaic system;

[0012] According to a size relationship between a string voltage of each of the target photovoltaic strings and the safety voltage, the target photovoltaic string is determined.

[0013] Optionally, in the method for identifying the access of the shutdown device in the photovoltaic system, the voltage perturbation is performed on at least one target photovoltaic string in the photovoltaic system, and the method comprises the following steps of:

[0014] The periodic conduction time and the target number of continuous perturbations of the target photovoltaic string are determined respectively.

[0015] The boost switch tube in the inverter corresponding to the target photovoltaic string is turned on, and the continuous perturbation is performed according to the periodic conduction time until the number of perturbations reaches the target number of continuous perturbations.

[0016] Optionally, in the method for identifying the access of the shutdown device in the photovoltaic system, after the voltage perturbation is performed on at least one target photovoltaic string in the photovoltaic system, the method further comprises the following steps of:

[0017] According to a size relationship between a string voltage of each of the target photovoltaic strings and the safety voltage, the target photovoltaic string is determined.

[0018] According to the multiple activation results of the shutdown device corresponding to at least one of the target photovoltaic strings, whether the photovoltaic system is accessed by the shutdown device is identified.

[0019] Optionally, in the method for identifying the access of the shutdown device in the photovoltaic system, according to a size relationship between a string voltage of each of the target photovoltaic strings and the safety voltage, the target photovoltaic string is determined.

[0020] If the string voltage of the target photovoltaic string is greater than the safety voltage, the activation result of the shutdown device corresponding to the target photovoltaic string is that the activation is successful.

[0021] If the string voltage of the target photovoltaic string is not greater than the safety voltage, the activation result of the shutdown device corresponding to the target photovoltaic string is that the activation fails.

[0022] Optionally, in the method for identifying the access of the shutdown device in the photovoltaic system, according to the multiple activation results of the shutdown device corresponding to at least one of the target photovoltaic strings, whether the photovoltaic system is accessed by the shutdown device is identified.

[0023] The activation success ratio and the activation failure ratio in the multiple activation results of the shutdown device corresponding to the target photovoltaic string are determined respectively.

[0024] According to the activation success proportion and the activation failure proportion, it is identified whether the photovoltaic system is connected with the shutdown device; wherein, if the activation success proportion is greater than the activation failure proportion, it is identified that the photovoltaic system is connected with the shutdown device, and if the activation success proportion is not greater than the activation failure proportion, it is identified that the photovoltaic system is not connected with the shutdown device.

[0025] Optionally, in the shutdown device connection identification method of the photovoltaic system, according to the multiple activation results of the shutdown device corresponding to the target photovoltaic string, it is identified whether the photovoltaic system is connected with the shutdown device, comprising:

[0026] The number of activation successes and / or the number of activation failures in the multiple activation results of the shutdown device corresponding to the target photovoltaic string are determined;

[0027] According to the number of activation successes and / or the number of activation failures, it is identified whether the photovoltaic system is connected with the shutdown device; wherein, if the number of activation successes is greater than a preset activation success threshold, it is identified that the photovoltaic system is connected with the shutdown device, and if the number of activation failures is greater than a preset activation failure threshold, it is identified that the photovoltaic system is not connected with the shutdown device.

[0028] Optionally, in the shutdown device connection identification method of the photovoltaic system, after judging whether there is at least one string voltage greater than the safety voltage in the string voltage of each disturbed target photovoltaic string, it further comprises:

[0029] If it is judged that there is no at least one string voltage greater than the safety voltage in the string voltage of each disturbed target photovoltaic string, it is identified that the photovoltaic system is not connected with the shutdown device.

[0030] The second aspect of the embodiments of the present application discloses a photovoltaic system operation mode setting method, comprising:

[0031] The shutdown device connection state of the photovoltaic system is determined; wherein, the shutdown device connection state is obtained by using any one of the shutdown device connection identification methods of the photovoltaic system disclosed in the first aspect;

[0032] According to the shutdown device connection state of the photovoltaic system, the operation mode that needs to be set for the photovoltaic system is determined.

[0033] Optionally, in the photovoltaic system operation mode setting method, according to the shutdown device connection state of the photovoltaic system, the operation mode that needs to be set for the photovoltaic system is determined, comprising:

[0034] If the shutdown device connection state of the photovoltaic system is connected, the operation mode that needs to be set for the photovoltaic system is the shutdown device system mode;

[0035] If the access state of the disconnector of the photovoltaic system is not accessed, the operation mode to be set for the photovoltaic system is the non-disconnector system mode.

[0036] The third aspect of the embodiments of the present application discloses a photovoltaic system, comprising at least one photovoltaic string, at least one inverter and a controller; the photovoltaic string is connected to a power grid through the inverter;

[0037] The controller is respectively connected in communication with the photovoltaic string and the inverter, and is used for executing the disconnector access identification method of the photovoltaic system according to any one of the first aspect, and / or the operation mode setting method of the photovoltaic system according to any one of the second aspect.

[0038] Optionally, in the photovoltaic system, the controller is arranged inside the inverter.

[0039] Based on the disconnector access identification method of the photovoltaic system provided by the embodiments of the present application, the method is to perform voltage disturbance on at least one target photovoltaic string in the photovoltaic system, the target photovoltaic string being a photovoltaic string with a string voltage lower than a safety voltage in the photovoltaic system; judging whether there is at least one string voltage greater than the safety voltage in the string voltages of each disturbed target photovoltaic string; if the result is yes, it is identified that the photovoltaic system is accessed to the disconnector, that is, the present application can utilize the characteristic that the disconnector needs to be disturbed by voltage at regular intervals to maintain continuous operation, and identify the access state of the photovoltaic system disconnector by the size relationship between the disturbed photovoltaic string voltage and the safety voltage, thereby solving the problem of complicated operation and occupying a large amount of manpower and material resources caused by the current way of confirming whether the photovoltaic system is accessed to the disconnector by the user on site. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only embodiments of the present application, and those skilled in the art can obtain other drawings according to the provided drawings without any creative effort.

[0041] Figure 1 A flowchart of the disconnector access identification method of the photovoltaic system provided by the embodiments of the present application;

[0042] Figure 2 A flowchart of voltage disturbance on the target photovoltaic string provided by the embodiments of the present application;

[0043] Figure 3 A voltage disturbance waveform diagram provided by the embodiments of the present application;

[0044] Figures 4 to 6 Another flowchart of a method for identifying access of a disconnector of a photovoltaic system according to an embodiment of the present application is provided as follows;

[0045] Figure 7 A flowchart of a method for setting an operation mode of a photovoltaic system according to an embodiment of the present application is provided as follows. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0047] In the present application, the term "comprising" or "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or further includes elements inherent to such a process, method, article or device. Without more limitations, the element defined by the phrase "including a" does not exclude the presence of additional identical elements in the process, method, article or device including the element.

[0048] The embodiments of the present application provide a method for identifying access of a disconnector of a photovoltaic system, to solve the problem of complicated operation and occupation of a large amount of manpower and resources caused by the current way that users confirm whether the photovoltaic system is connected to the disconnector through the field.

[0049] Please refer to Figure 1 The method for identifying access of a disconnector of a photovoltaic system mainly includes the following steps:

[0050] S101, performing voltage disturbance on at least one target photovoltaic string in the photovoltaic system.

[0051] The target photovoltaic string is a photovoltaic string in the photovoltaic system whose string voltage is lower than a safety voltage.

[0052] Specifically, the safety voltage can be a voltage on the photovoltaic string when the disconnector corresponding to the photovoltaic string in the photovoltaic system is in an inactive state, for example, 30V, which is not limited in the present application and is within the protection scope of the present application.

[0053] In actual application, the specific process of performing voltage disturbance on at least one target photovoltaic string in the photovoltaic system in step S101 can be as shown in Figure 2 which mainly includes steps S201 and S202:

[0054] S201, respectively determine the periodic conduction time of the target photovoltaic string and the target number of continuous disturbances.

[0055] The periodic conduction time of the target photovoltaic string can be the conduction time of the target photovoltaic string in each disturbance period. Assuming that the periodic conduction time is Tp and the disturbance period is T, the relationship between the periodic conduction time Tp and the disturbance period T can be as shown in the following formula. Figure 3

[0056] It should be noted that the target number of continuous disturbances generally needs to be determined in combination with the specific situation in which the shutdown device is determined to be activated successfully. The target number of continuous disturbances is generally the number of disturbances required for the shutdown device to be determined to be activated successfully. Specifically, if it is assumed that the shutdown device is considered to be activated successfully after 10 continuous disturbances, the target number of continuous disturbances can be 10.

[0057] S202, turn on the boost switch tube in the inverter corresponding to the target photovoltaic string, and continuously disturb according to the periodic conduction time until the number of disturbances reaches the target number of continuous disturbances.

[0058] In actual application, during the disturbance of the photovoltaic string, the boost switch tube in the inverter corresponding to the target photovoltaic string can be turned on first, and the conduction time of the boost switch is set to the periodic conduction time in each disturbance period, so as to realize one disturbance of the target photovoltaic module. The above operation is repeated continuously until the number of disturbances reaches the target number of continuous disturbances.

[0059] It should be noted that in addition to the voltage disturbance mode shown above, other disturbance modes can also be used in actual application to realize voltage disturbance of the target photovoltaic module. The specific disturbance implementation mode is not limited in the present application, and is within the protection scope of the present application.

[0060] In actual application, before performing step S101, voltage disturbance on at least one target photovoltaic string in the photovoltaic system, as shown in the following formula, the shutdown device access identification method of the photovoltaic system can further include steps S301 and S302: Figure 4

[0061] S301, respectively acquire the string voltage of each photovoltaic string in the photovoltaic system.

[0062] In some embodiments, the string voltage of each photovoltaic string can be acquired by setting a corresponding voltage sensor in each photovoltaic string to acquire the string voltage of each photovoltaic string through the sensor. Of course, the string voltage of each photovoltaic string in the photovoltaic system can also be acquired by other existing methods, which are not limited in the present application and are within the protection scope of the present application.

[0063] ​​S302, determining the target photovoltaic string according to the size relationship between the string voltage of each photovoltaic string and the safety voltage.

[0064] In some embodiments, after obtaining the string voltage of each photovoltaic string in the photovoltaic system, the photovoltaic string with a voltage less than the safety voltage can be determined as the target photovoltaic string based on the size relationship between the string voltage of each photovoltaic string and the safety voltage.

[0065] It should be noted that the specific number of target photovoltaic strings in the photovoltaic system that need to be subjected to voltage disturbance can be determined according to the application environment and user demand, and the present application does not limit the same, which is within the protection scope of the present application.

[0066] It should be further noted that the more the number of target photovoltaic strings participating in the disturbance, the higher the accuracy of the access condition of the shut-off device in the photovoltaic system determined according to the disturbance result.

[0067] S102, judging whether there is at least one string voltage greater than the safety voltage in the string voltage of each disturbed target photovoltaic string.

[0068] In actual application, it can be judged whether the string voltage of each disturbed target photovoltaic string is greater than the safety voltage, so as to judge whether there is at least one string voltage greater than the safety voltage in the string voltage of each disturbed target photovoltaic string.

[0069] If it is judged that there is at least one string voltage greater than the safety voltage in the string voltage of each disturbed target photovoltaic string, that is, the judgment result is yes, then step S103 is executed.

[0070] S103, identifying that the photovoltaic system accesses the shut-off device.

[0071] Since the photovoltaic system accessing the shut-off device needs to be disturbed at regular intervals to maintain the continuous operation of the shut-off device, otherwise the shut-off device will be closed automatically, the machine has no output power, and the power station power generation is greatly affected; the photovoltaic system not accessing the shut-off device does not need to be disturbed at regular intervals. Therefore, the voltage of the target photovoltaic string can be disturbed, and whether the photovoltaic system accesses the shut-off device can be identified according to the size relationship between the string voltage change of the target photovoltaic string after the disturbance and the safety voltage.

[0072] Specifically, for each disturbed target photovoltaic string, it can be judged whether its string voltage is greater than the safety voltage, and if it is judged that there is at least one string voltage of the disturbed target photovoltaic string greater than the safety voltage, it can be identified that the photovoltaic system accesses the shut-off device.

[0073] Based on the above principle, the method for identifying the access of the shutdown device of the photovoltaic system provided in the embodiment includes: performing voltage disturbance on at least one target photovoltaic string in the photovoltaic system, the target photovoltaic string being a photovoltaic string with a string voltage lower than a safe voltage in the photovoltaic system; determining whether there is at least one string voltage greater than the safe voltage in the string voltages of each disturbed target photovoltaic string; and if the result is yes, identifying that the photovoltaic system is accessed to the shutdown device. That is, the present application can identify the access state of the shutdown device of the photovoltaic system by using the characteristic that the shutdown device needs to be disturbed by voltage at regular intervals to keep continuous operation, and by determining the size relationship between the disturbed photovoltaic string voltage and the safe voltage, thereby solving the problem of complicated operation and occupation of a large amount of manpower and resources caused by the current way of confirming whether the photovoltaic system is accessed to the shutdown device by the user on site.

[0074] Optionally, in another embodiment provided in the present application, after performing step S102 of determining whether there is at least one string voltage greater than the safe voltage in the string voltages of each disturbed target photovoltaic string, if it is determined that there is no at least one string voltage greater than the safe voltage in the string voltages of each disturbed target photovoltaic string, please refer to Figure 5 , the method for identifying the access of the shutdown device of the photovoltaic system further includes:

[0075] S401, identifying that the photovoltaic system is not accessed to the shutdown device.

[0076] In actual application, in the case that the shutdown device is accessed to the photovoltaic system, after the target photovoltaic string in the photovoltaic system is disturbed, the string voltage of the target photovoltaic string will rise and exceed the safe voltage. Therefore, whether the photovoltaic system is accessed to the shutdown device can be identified by determining whether the string voltage of each disturbed target photovoltaic string is greater than the safe voltage.

[0077] If it is determined that the string voltage of all disturbed target photovoltaic strings is not greater than the safe voltage, it can be identified that the photovoltaic system is accessed to the shutdown device.

[0078] It should be noted that, in addition to using the criterion that the string voltage of all disturbed target photovoltaic strings is not greater than the safe voltage as the criterion for identifying that the photovoltaic system is not accessed to the shutdown device, in actual application, other criteria can also be used as the criterion for identifying that the photovoltaic system is not accessed to the shutdown device according to specific conditions and user requirements, such as the voltage of most target photovoltaic strings in all disturbed target photovoltaic strings is not greater than the safe voltage, or the string voltage of at least one disturbed target photovoltaic string is not greater than the safe voltage, and the like.

[0079] It should be further noted that in specific application, the compatibility of the criterion for identifying that the photovoltaic system is accessed to the shutdown device and the criterion for identifying that the photovoltaic system is not accessed to the shutdown device should be considered to ensure that the two criteria do not conflict, so as to avoid affecting the implementation of the present application.

[0080] Optionally, in another embodiment provided in this application, after performing step S101, which involves voltage perturbation of at least one target photovoltaic string in the photovoltaic system, please refer to... Figure 6 The photovoltaic system's switchgear connection identification method also includes:

[0081] S501. For each disturbed target photovoltaic string, determine the activation result of the corresponding shutdown device for each target photovoltaic string based on the relationship between the string voltage and the safety voltage of the disturbed target photovoltaic string.

[0082] In practical applications, the activation result of the shutdown device can be divided into activation success and activation failure. Specifically, if the string voltage of the target photovoltaic string is greater than the safe voltage, the activation result of the shutdown device corresponding to that target photovoltaic string can be determined as: activation success; if the string voltage of the target photovoltaic string is not greater than the safe voltage, the activation result of the shutdown device corresponding to that target photovoltaic string can be determined as: activation failure.

[0083] It should be noted that, to ensure the accuracy of the activation results of the shutdown devices corresponding to the identified target photovoltaic strings, after perturbing the voltage of at least one target photovoltaic string in the photovoltaic system, a certain period of time can be waited before determining the activation results of the shutdown devices corresponding to each target photovoltaic string based on the relationship between the string voltage and the safe voltage of the perturbed target photovoltaic string. The specific waiting time can be determined according to the specific application and user requirements, such as 10s, 20s, etc., all of which are within the scope of protection of this application.

[0084] S502. Based on the multiple activation results of the switch corresponding to at least one target photovoltaic string, identify whether the photovoltaic system is connected to the switch.

[0085] In practical applications, each pair of target photovoltaic strings undergoes a voltage perturbation once, i.e., by executing step S101 sequentially, resulting in one activation result for the corresponding shutdown device of the target photovoltaic string. Therefore, multiple activation results for the shutdown device corresponding to the target photovoltaic string require multiple voltage perturbations of the target photovoltaic string. The specific number of perturbations can be determined according to the application environment and user requirements; for example, the number of perturbations can be set to 3, 5, 7, 9, etc., all of which are within the scope of protection of this application.

[0086] It should be noted that the multiple activation results of the shutdown device corresponding to the target photovoltaic string can be the activation results of the corresponding shutdown device during multiple consecutive voltage disturbances of the target photovoltaic string. Of course, it is not limited to this; it can also be the activation results of the shutdown device corresponding to multiple disturbances of the target photovoltaic string within a preset time period, depending on the specific application environment and user needs, all of which are within the protection scope of this application.

[0087] In some embodiments, the specific process of performing step S502, identifying whether the photovoltaic system is connected to the shutdown device according to the multiple activation results of the shutdown device corresponding to the target photovoltaic string, can be as follows, mainly including steps S601 and S602:

[0088] S601, respectively determining the activation success ratio and the activation failure ratio in the multiple activation results of the shutdown device corresponding to the target photovoltaic string.

[0089] In practice, assuming that the total number of the multiple activation results of the shutdown device corresponding to the target photovoltaic string is A, the number of activation successes is B, and the number of activation failures is C, the activation success ratio can be determined by B / A, and the activation failure ratio can be determined by C / A.

[0090] S602, identifying whether the photovoltaic system is connected to the shutdown device according to the activation success ratio and the activation failure ratio.

[0091] Wherein, if the activation success ratio is greater than the activation failure ratio, it is identified that the photovoltaic system is connected to the shutdown device, and if the activation success ratio is not greater than the activation failure ratio, it is identified that the photovoltaic system is not connected to the shutdown device.

[0092] Assuming that the activation success ratio is greater than 50% and the activation failure ratio is less than 50%, it can be identified that the photovoltaic system is connected to the shutdown device; assuming that the activation success ratio is less than 50% and the activation failure ratio is greater than 50%, it can be identified that the photovoltaic system is not connected to the shutdown device.

[0093] In some embodiments, the specific process of performing step S502, identifying whether the photovoltaic system is connected to the shutdown device according to the multiple activation results of the shutdown device corresponding to the target photovoltaic string, can also be as follows, mainly including steps S701 and S702:

[0094] SS701, determining the number of activation successes and / or the number of activation failures in the multiple activation results of the shutdown device corresponding to the target photovoltaic string.

[0095] In practical application, the number of activation successes and / or the number of activation failures in the multiple activation results of the shutdown device corresponding to the target photovoltaic string can be determined by statistical means.

[0096] S702, identifying whether the photovoltaic system is connected to the shutdown device according to the number of activation successes and / or the number of activation failures.

[0097] Wherein, if the number of activation successes is greater than a preset activation success threshold, it is identified that the photovoltaic system is connected to the shutdown device, and if the number of activation failures is greater than a preset activation failure threshold, it is identified that the photovoltaic system is not connected to the shutdown device.

[0098] In actual application, the preset activation success threshold and the preset activation failure threshold are generally preset, and the two can be the same or different, and can be determined according to application environment and user demand, which is not limited in the present application and is within the protection scope of the present application.

[0099] Based on the above principle, the disconnector access identification method of the photovoltaic system provided in the embodiment can identify whether the photovoltaic system is connected to the disconnector through the multiple activation results of the target photovoltaic string corresponding to the disconnector. Compared with the method of directly determining whether the photovoltaic system is connected to the disconnector by judging whether the string voltage of the disturbed target photovoltaic string is greater than the safety voltage, the accuracy is higher.

[0100] In actual application, because the operation control mode of the photovoltaic system corresponding to the disconnector is different, if the operation mode setting of the photovoltaic system is inconsistent with the disconnector access state of the photovoltaic system, the photovoltaic system cannot operate normally. Based on this, on the basis of the disconnector access identification method of the photovoltaic system provided in the above embodiment, another embodiment of the present application further provides an operation mode setting method of the photovoltaic system, which can avoid the problem that the photovoltaic system cannot operate normally due to the inconsistency between the operation mode setting of the photovoltaic system and the disconnector access state of the photovoltaic system.

[0101] Please refer to Figure 7 The operation mode setting method of the photovoltaic system mainly includes:

[0102] S801, determining the disconnector access state of the photovoltaic system.

[0103] The disconnector access state is obtained by using the disconnector access identification method of the photovoltaic system according to any one of the above embodiments.

[0104] It should be noted that the specific process of determining the disconnector access state of the photovoltaic system can be referred to the corresponding embodiment described above, which will not be repeated here.

[0105] S802, determining the operation mode to be set of the photovoltaic system according to the disconnector access state of the photovoltaic system.

[0106] In actual application, if the disconnector access state of the photovoltaic system is connected, the operation mode to be set of the photovoltaic system is the disconnector system mode; if the disconnector access state of the photovoltaic system is not connected, the operation mode to be set of the photovoltaic system is the non-disconnector system mode.

[0107] In the embodiment, the access state of the shutdown device of the photovoltaic system can be determined by intelligent identification without the user confirming on site, the determination accuracy of the access state of the shutdown device of the photovoltaic system obtained by the access state identification method of the shutdown device of the photovoltaic system is high, the running mode of the photovoltaic system determined based on the access state of the shutdown device of the photovoltaic system is more reliable, and the running mode of the photovoltaic system does not need to be manually set by the user, which can effectively avoid the problem that the running mode of the photovoltaic system is inconsistent with the access state of the shutdown device of the photovoltaic system, and the photovoltaic system cannot normally run.

[0108] Based on the access state identification method of the shutdown device of the photovoltaic system and the running mode setting method of the photovoltaic system provided in the above embodiments, another embodiment of the present application further provides a photovoltaic system, which comprises:

[0109] at least one photovoltaic string, at least one inverter, and a controller. The photovoltaic string is connected to a power grid through the inverter.

[0110] The controller is in communication with the photovoltaic string and the inverter, respectively, and is used to execute the access state identification method of the shutdown device of the photovoltaic system as described in any of the above embodiments, and / or the running mode setting method of the photovoltaic system as described in any of the above embodiments.

[0111] In actual application, the photovoltaic string can include at least one photovoltaic component. The inverter can be a photovoltaic inverter or a storage inverter. In actual application, the inverter can also be connected to an optional load.

[0112] In some embodiments, the controller can store programs, variables, and electronic devices supporting information interaction, and can be used to execute the access state identification method of the shutdown device of the photovoltaic system as described in any of the above embodiments, and / or the running mode setting method of the photovoltaic system as described in any of the above embodiments.

[0113] It should be noted that in actual application, the controller can be arranged in the inverter. Of course, it is not limited to this, and can be determined according to specific application environment and user demand, which is not limited in the present application and is within the protection scope of the present application.

[0114] In the embodiment, the controller can execute the access state identification method of the shutdown device of the photovoltaic system as described in any of the above embodiments, and / or the running mode setting method of the photovoltaic system as described in any of the above embodiments, to intelligently identify whether the photovoltaic system is connected to the shutdown device and set the running mode of the photovoltaic system, which is safe and reliable, does not require any hardware cost, saves manpower selection, improves customer experience, and improves the competitiveness of the product.

[0115] The various embodiments described in this specification are described in progressive order, and each embodiment can be understood independently of the other embodiments. Each embodiment is directed to the differences between the embodiments. For example, for the system or system embodiments, the description is relatively simple because the system embodiments are substantially similar to the method embodiments. The system embodiments are described with reference to the method embodiments. The system and system embodiments described above are merely illustrative of the principles of the application. The units shown as separate components in the above description can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., can be located at one place or distributed over multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purposes of the embodiments. Those skilled in the art can understand and implement without creative labor.

[0116] Those skilled in the art will further appreciate that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the examples have been described in general terms above. Whether the functions are performed in hardware or software depends on the particular application and design constraints. Those skilled in the art can implement the described functions in different ways for each particular application, but such implementation should not be considered to be beyond the scope of the present application.

[0117] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to the embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for shutdown switch access identification of a photovoltaic system, characterized in that, The method comprises: performing voltage perturbation on at least one target photovoltaic string in the photovoltaic system, the target photovoltaic string being a photovoltaic string in the photovoltaic system with a string voltage lower than a safety voltage; determining whether at least one of the string voltages of each perturbed target photovoltaic string is greater than the safety voltage; if the determination result is yes, identifying that the photovoltaic system is connected to a shutdown device.

2. The method of claim 1, wherein the method further comprises: Before performing voltage perturbation on at least one target photovoltaic string in the photovoltaic system, the method further comprises: obtaining the string voltage of each photovoltaic string in the photovoltaic system respectively; determining the target photovoltaic string according to the size relationship between the string voltage of each photovoltaic string and the safety voltage.

3. The method of claim 1, wherein the method further comprises: The performing voltage perturbation on at least one target photovoltaic string in the photovoltaic system comprises: determining the periodic conduction time and the target number of continuous perturbations of the target photovoltaic string respectively; turning on the boost switch tube in the inverter corresponding to the target photovoltaic string, and performing continuous perturbation according to the periodic conduction time until the perturbation number reaches the target number of continuous perturbations.

4. The method of claim 1, wherein the method further comprises: After performing voltage perturbation on at least one target photovoltaic string in the photovoltaic system, the method further comprises: for each perturbed target photovoltaic string, determining the activation result of the shutdown device corresponding to the target photovoltaic string according to the size relationship between the string voltage of the perturbed target photovoltaic string and the safety voltage; identifying whether the photovoltaic system is connected to a shutdown device according to the multiple activation results of the shutdown device corresponding to at least one target photovoltaic string.

5. The method of claim 4, wherein the method further comprises: For each perturbed target photovoltaic string, determining the activation result of the shutdown device corresponding to the target photovoltaic string according to the size relationship between the string voltage of the perturbed target photovoltaic string and the safety voltage comprises: if the string voltage of the target photovoltaic string is greater than the safety voltage, the activation result of the shutdown device corresponding to the target photovoltaic string is activation success; if the string voltage of the target photovoltaic string is not greater than the safety voltage, the activation result of the shutdown device corresponding to the target photovoltaic string is activation failure.

6. The method of claim 4, wherein the method further comprises: Identifying whether the photovoltaic system is connected to a shutdown device according to the multiple activation results of the shutdown device corresponding to at least one target photovoltaic string comprises: determining the activation success ratio and the activation failure ratio in the multiple activation results of the shutdown device corresponding to the target photovoltaic string respectively; identifying whether the photovoltaic system is connected to a shutdown device according to the activation success ratio and the activation failure ratio; wherein, if the activation success ratio is greater than the activation failure ratio, it is identified that the photovoltaic system is connected to a shutdown device, and if the activation success ratio is not greater than the activation failure ratio, it is identified that the photovoltaic system is not connected to a shutdown device.

7. The method of claim 4, wherein the method further comprises: Identifying whether the photovoltaic system is connected to a shutdown device according to the multiple activation results of the shutdown device corresponding to at least one target photovoltaic string comprises: determining the number of activation successes and / or the number of activation failures in the multiple activation results of the shutdown device corresponding to the target photovoltaic string; According to the number of successful activations and / or the number of failed activations, it is identified whether the photovoltaic system is connected to the shutdown device; wherein if the number of successful activations is greater than a preset threshold of successful activations, it is identified that the photovoltaic system is connected to the shutdown device, and if the number of failed activations is greater than a preset threshold of failed activations, it is identified that the photovoltaic system is not connected to the shutdown device.

8. The method of claim 1, wherein the method further comprises: After judging whether there is at least one string voltage greater than the safety voltage in the string voltage of each disturbed target photovoltaic string, further comprising: If it is judged that there is no at least one string voltage greater than the safety voltage in the string voltage of each disturbed target photovoltaic string, it is identified that the photovoltaic system is not connected to the shutdown device.

9. A method of setting an operating mode of a photovoltaic system, characterized by, Comprising: The shutdown device connection state of the photovoltaic system is determined; wherein the shutdown device connection state is obtained by using the shutdown device connection identification method of the photovoltaic system according to any one of claims 1-8; According to the shutdown device connection state of the photovoltaic system, the operation mode that needs to be set for the photovoltaic system is determined.

10. The method of claim 9, wherein, According to the shutdown device connection state of the photovoltaic system, the operation mode that needs to be set for the photovoltaic system is determined, comprising: If the shutdown device connection state of the photovoltaic system is connected, the operation mode that needs to be set for the photovoltaic system is the shutdown device system mode; If the shutdown device connection state of the photovoltaic system is not connected, the operation mode that needs to be set for the photovoltaic system is the non-shutdown device system mode.

11. A photovoltaic system characterized by, Comprising: At least one photovoltaic string, at least one inverter and a controller; the photovoltaic string is connected to the power grid through the inverter; The controller is respectively connected in communication with the photovoltaic string and the inverter, and is used to execute the shutdown device connection identification method of the photovoltaic system according to any one of claims 1-8, and / or the operation mode setting method of the photovoltaic system according to any one of claims 9 or 10.

12. The photovoltaic system of claim 11, wherein, The controller is arranged inside the inverter.

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