Optimizer identification method, photovoltaic system, optimizer identification device, and storage medium

Abstract

The application provides an optimizer identification method, a photovoltaic system, an optimizer identification device and a storage medium. The optimizer identification method is applied to the photovoltaic system. The method starts the first optimizer by controlling the first optimizer to have a first set output voltage. The first bus voltage is obtained when the first optimizer is started. The photovoltaic string attribution relationship of each first optimizer is determined according to the first bus voltage and the first set output voltage. Then, the second optimizer is started in turn by controlling each second optimizer to have a second set output voltage based on the photovoltaic string attribution relationship of at least one first optimizer. The second bus voltage is obtained when the second optimizer is started. The photovoltaic string attribution relationship of the second optimizer is determined based on the second bus voltage, the first set output voltage, the second set output voltage and the photovoltaic string attribution relationship of the first optimizer. Thus, the topology relationship of each photovoltaic string of the photovoltaic system is obtained. The optimizer identification method can intelligently identify the topology relationship of the photovoltaic string.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, specifically to an optimizer identification method, a photovoltaic system, an optimizer identification device, and a storage medium. Background Technology

[0002] With the large-scale application of photovoltaic (PV) modules, multiple PV modules are often connected in series to form a single PV string, and these multiple PV strings are connected to an inverter circuit via DC buses. In some PV systems, each PV module is equipped with an optimizer at its output terminal. The optimizer, also known as a power optimizer, is a DC-input, DC-output power electronic device used to optimize the output power of the PV module. In related technologies, the topology of PV strings needs to be manually recorded. However, this manual method has many drawbacks, such as: it is time-consuming and labor-intensive; it is prone to errors in recording or configuration, leading to safety risks and increasing the difficulty of troubleshooting; and it has low operation and maintenance efficiency and poor adaptability. Summary of the Invention

[0003] In view of this, this application provides an optimizer identification method, a photovoltaic system, an optimizer identification device, and a storage medium, which can intelligently identify the topological relationship of photovoltaic strings in a photovoltaic system and avoid many shortcomings caused by manual recording.

[0004] The first aspect of this application provides an optimizer identification method applied to a photovoltaic system. The photovoltaic system includes an inverter circuit and at least two photovoltaic strings. Each photovoltaic string includes multiple photovoltaic modules and multiple optimizers. The output terminal of each photovoltaic module is connected to the input terminal of a corresponding optimizer. The output terminals of the optimizers in each photovoltaic string are connected in series and then connected to the inverter circuit via a DC bus. The method includes: controlling a preset number of first optimizers to start with a corresponding first set output voltage; wherein, different first optimizers correspond to different first set voltages; when the first optimizer starts, acquiring the first bus voltage of the DC bus, and determining the first bus voltage and the first set output voltage accordingly. The photovoltaic string affiliation relationship of each first optimizer is determined; based on the photovoltaic string affiliation relationship of at least one first optimizer, each second optimizer is controlled to start sequentially with a corresponding second set output voltage; the second optimizers are the other optimizers in the photovoltaic system besides the first optimizers; when the second optimizer starts, the second bus voltage of the DC bus is obtained; based on the second bus voltage, the first set output voltage, the second set output voltage, and the photovoltaic string affiliation relationship of the first optimizer, the photovoltaic string affiliation relationship of the second optimizer is determined; according to the photovoltaic string affiliation relationship of the first optimizer and the photovoltaic string affiliation relationship of the second optimizer, the topology relationship of each photovoltaic string in the photovoltaic system is obtained.

[0005] The optimizer identification method of this application includes controlling a preset number of first optimizers to start with corresponding first set output voltages; acquiring the first bus voltage of the DC bus when the first optimizer starts; determining the photovoltaic string affiliation of each first optimizer based on the first bus voltage and the first set output voltage; then, based on the photovoltaic string affiliation of at least one first optimizer, controlling each second optimizer to start sequentially with corresponding second set output voltages; acquiring the second bus voltage of the DC bus when the second optimizer starts; and determining the photovoltaic string affiliation of the second optimizer based on the second bus voltage, the first set output voltage, the second set output voltage, and the photovoltaic string affiliation of the first optimizer; finally, obtaining the topology of each photovoltaic string in the photovoltaic system based on the photovoltaic string affiliation of the first and second optimizers. Understandably, since different first optimizers correspond to different first set output voltages, the DC bus can generate corresponding and specific first bus voltages based on the first set output voltage of each first optimizer and the photovoltaic string affiliation. Therefore, the photovoltaic string affiliation of each first optimizer can be deduced from the first bus voltage and the first set output voltage. Since the DC bus generates different second bus voltages depending on whether the second optimizer and the first optimizer belong to the same photovoltaic string or different photovoltaic strings, the photovoltaic string belonging relationship of the second optimizer can be deduced from the second bus voltage, the first set output voltage, the second set output voltage, and the photovoltaic string belonging relationship of the first optimizer. Finally, the number of parallel photovoltaic strings and the number of optimizers connected in series on each photovoltaic string can be determined based on the photovoltaic string belonging relationship of the first and second optimizers, thus obtaining the topology of the photovoltaic strings. Therefore, the optimizer identification method of this application can intelligently identify the topology of photovoltaic strings in a photovoltaic system, avoiding many shortcomings caused by manually recording the topology of photovoltaic strings.

[0006] In one embodiment, the preset number of first optimizers is at least two; the value of the first set output voltage corresponding to each first optimizer is a prime number and unique, and the summation result of the first set output voltage after any combination of the first optimizers is unique.

[0007] In one embodiment, determining the photovoltaic string affiliation of each first optimizer based on the first bus voltage and the first set output voltage includes: if the first bus voltage is equal to the maximum value among the first set output voltages corresponding to each first optimizer, then each first optimizer is determined to belong to different photovoltaic strings; or, if the first bus voltage is equal to the sum of the first set output voltages corresponding to at least two first optimizers, then at least two first optimizers are determined to belong to the same photovoltaic string.

[0008] In one embodiment, determining the photovoltaic string affiliation of the second optimizer based on the second bus voltage, the first set output voltage, the second set output voltage, and the photovoltaic string affiliation of the first optimizer includes: under the photovoltaic string affiliation of the first optimizer, obtaining the sum of the second set output voltage and any one of the first set output voltages; if the second bus voltage is equal to the sum of the second set output voltage and the first set output voltage corresponding to one of the activated first optimizers, then it is determined that the second optimizer and the corresponding first optimizer are located in the same photovoltaic string; otherwise, it is determined that the second optimizer and any one of the first optimizers are not in the same photovoltaic string.

[0009] In one embodiment, the preset number of first optimizers is three, and the sum of the first set output voltages corresponding to any two first optimizers is greater than the first set output voltages corresponding to the remaining first optimizers. Determining the photovoltaic string affiliation of each first optimizer based on the first bus voltage and the first set output voltage includes: when the first bus voltage is equal to the sum of the first set output voltages corresponding to the three first optimizers, determining that the three first optimizers belong to the same photovoltaic string; when the first bus voltage is equal to the sum of the first set output voltages corresponding to any two first optimizers, determining that the corresponding two first optimizers belong to the same photovoltaic string, and the remaining first optimizers belong to another photovoltaic string; when the first bus voltage is equal to the maximum value among the first set output voltages corresponding to each first optimizer, determining that the three first optimizers belong to different photovoltaic strings.

[0010] In one embodiment, the method further includes: determining the target output voltage of each optimizer corresponding to each photovoltaic string based on the set target bus voltage and the topology of each photovoltaic string; and controlling the operation of each optimizer based on the target output voltage of each optimizer.

[0011] In one embodiment, before controlling a preset number of first optimizers to start with a corresponding first set output voltage, the method further includes: obtaining optimizer identifiers of each optimizer and controlling each optimizer to be in a standby state; obtaining the detection order of each optimizer according to the size relationship of the optimizer identifiers, and taking the preset number of optimizers detected first as the first optimizer, and taking the remaining optimizers detected later than the first optimizer as the second optimizer.

[0012] The second aspect of this application provides a photovoltaic system, which includes an inverter circuit, a controller, and at least two photovoltaic strings. Each photovoltaic string includes multiple photovoltaic modules and multiple optimizers. The output terminal of each photovoltaic module is connected to the input terminal of the corresponding optimizer. The output terminals of the optimizers in each photovoltaic string are connected in series and then connected to the inverter circuit through a DC bus. The controller is used to execute the optimizer identification method described in the first aspect or any embodiment of the first aspect.

[0013] A third aspect of this application provides an electronic device, including a processor and a memory, wherein the memory is used to store programs, instructions or code, and the processor is used to execute the programs, instructions or code in the memory to perform the optimizer identification method described in the first aspect or any embodiment of the first aspect.

[0014] This application provides a fourth aspect of an optimizer identification device, comprising a first control module, a first determination module, a second control module, an acquisition module, a second determination module, and a third determination module; the first control module is used to control a preset number of first optimizers to start with corresponding first set output voltages; wherein, different first optimizers correspond to different first set voltages; the first determination module is used to acquire the first bus voltage of the DC bus when the first optimizer starts, and determine the photovoltaic string affiliation relationship of each first optimizer according to the first bus voltage and the first set output voltage; the second control module is used to control each second optimizer to start sequentially with corresponding second set output voltages based on the photovoltaic string affiliation relationship of at least one first optimizer; the second optimizers are the remaining optimizers in the photovoltaic system other than the first optimizers; the acquisition module is used to acquire the second bus voltage of the DC bus when the second optimizer starts; the second determination module is used to determine the photovoltaic string affiliation relationship of the second optimizer based on the second bus voltage, the first set output voltage, the second set output voltage, and the photovoltaic string affiliation relationship of the first optimizer; the third determination module is used to obtain the topology relationship of each photovoltaic string in the photovoltaic system according to the photovoltaic string affiliation relationship of the first optimizer and the photovoltaic string affiliation relationship of the second optimizer.

[0015] The fifth aspect of this application provides a computer-readable storage medium storing a computer program, which, when executed by a controller, causes the controller to implement the optimizer identification method described in the first aspect or any embodiment of the first aspect.

[0016] Furthermore, the technical effects of any of the embodiments in the second to fifth aspects can be found in the technical effects of the different embodiments in the first aspect, and will not be repeated here. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a photovoltaic system provided in one embodiment of this application.

[0018] Figure 2 This is a flowchart of an optimizer identification method provided in an embodiment of this application.

[0019] Figure 3 yes Figure 2 A detailed flowchart of step S15.

[0020] Figure 4 This is another flowchart of an optimizer identification method provided in one embodiment of this application.

[0021] Figure 5 This is yet another flowchart of an optimizer identification method provided in one embodiment of this application.

[0022] Figure 6 This is a schematic diagram of an electronic device provided in an embodiment of this application.

[0023] Figure 7 This is a schematic diagram of an optimizer identification device provided in an embodiment of this application. Detailed Implementation

[0024] It should be noted that the terms "first" and "second" in the specification, claims and drawings of this application are used to distinguish similar objects, rather than to describe a specific order or sequence.

[0025] It should also be noted that the methods disclosed in the embodiments of this application or the methods shown in the flowcharts include one or more steps for implementing the method. Without departing from the scope of the claims, the execution order of multiple steps can be interchanged, and some steps can also be deleted.

[0026] Some embodiments will now be described with reference to the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0027] With the large-scale application of photovoltaic (PV) modules, multiple PV modules are often connected in series to form a single PV string. These multiple PV strings are then connected to an inverter circuit via DC buses. Each PV module is equipped with an optimizer at its output terminal. The optimizer, also known as a power optimizer, is a DC-input, DC-output power electronic device used to optimize the output power of the PV module.

[0028] In related technologies, the topology of photovoltaic (PV) strings needs to be manually recorded. However, this manual method has many drawbacks, such as: it is time-consuming and labor-intensive; it is prone to errors in recording or configuration, leading to misjudgments of the optimizer's position and the length of the PV strings, as well as mis-controlling the optimizer. This can result in uneven total output voltage across different PV strings, or the output voltage of the entire PV string exceeding the inverter's withstand voltage, causing circulating currents between PV strings, inverter overvoltage damage, and other safety risks. It also increases the difficulty of troubleshooting when PV strings malfunction. Furthermore, whenever PV strings are added or removed, or the optimizer is replaced, manual re-recording and reconfiguration are required, resulting in low operation and maintenance efficiency and poor adaptability.

[0029] Therefore, this application provides an optimizer identification method that can intelligently identify the topological relationship of photovoltaic strings in a photovoltaic system, avoiding many shortcomings caused by manual recording.

[0030] The technical solution of this application will be further described in detail below with reference to the accompanying drawings.

[0031] Figure 1 The diagram illustrates an application scenario of the optimizer identification method provided in this application. Figure 1 The scenario is a photovoltaic system 100. The photovoltaic system 100 includes an inverter circuit 20 and at least two photovoltaic strings 10, which are connected in parallel to form a photovoltaic array and connected to the DC terminal of the inverter circuit 20.

[0032] The photovoltaic system 100 can be a distributed photovoltaic system, such as a rooftop photovoltaic system or a balcony photovoltaic system, etc., without any restrictions.

[0033] Each photovoltaic string 10 includes multiple photovoltaic modules 11 and multiple optimizers 12. The number of photovoltaic modules 11 and optimizers 12 in different photovoltaic strings 10 can be the same or different. For ease of demonstration, Figure 1 The example below illustrates a photovoltaic string of 10, which includes n photovoltaic modules 11 and n optimizers 12, where n is a positive integer greater than 2, and the n photovoltaic modules 11 and n optimizers 12 correspond one-to-one.

[0034] The output terminals of each photovoltaic module 11 in each photovoltaic string 10 are connected to the input terminals of the corresponding optimizer 12. The output terminals of the optimizers 12 in each photovoltaic string 10 are connected in series and then connected to the DC terminal of the inverter circuit 20 through DC buses (BUS+, BUS-). Therefore, the optimizers 12 in the same photovoltaic string 10 are connected in series, while the optimizers 12 in different photovoltaic strings 10 are connected in parallel.

[0035] Based on this design, the photovoltaic power generated by each photovoltaic module 11 in each photovoltaic string 10 is output through the corresponding optimizer 12. The optimizer 12 can track the maximum power point of the photovoltaic module 11, ensuring that the photovoltaic module 11 always outputs maximum power. All the photovoltaic power of each photovoltaic string 10 is transmitted to the inverter circuit 20 through the DC bus. The inverter circuit 20 can convert the received photovoltaic power to supply power to the load (not shown in the figure) on the AC terminal of the inverter circuit 20.

[0036] The output voltage of each photovoltaic string 10 is equal to the sum of the output voltages of each optimizer 12 connected in series within that photovoltaic string 10. For example... Figure 1In the above, the output voltage V1 of photovoltaic string A is equal to the sum of the output voltages of the n optimizers 12 in photovoltaic string A (such as V11, V12, ..., V1n), that is, V1 = V11 + V12 + ... + V1n. The output voltage V2 of photovoltaic string B is equal to the sum of the output voltages of the n optimizers 12 in photovoltaic string B (such as V21, V22, ..., V2n), that is, V2 = V21 + V22 + ... + V2n.

[0037] When only the optimizer 12 in one photovoltaic string 10 is started, the bus voltage Vbus on the DC bus is equal to the output voltage of that photovoltaic string 10.

[0038] When all the optimizers 12 in the parallel photovoltaic strings 10 are started, the bus voltage Vbus on the DC bus is equal to the maximum value of the output voltages of the parallel photovoltaic strings 10, that is, equal to the maximum value of the output voltages of the optimizers 12 belonging to different photovoltaic strings 10. For example Figure 1 In the photovoltaic system 100, the output voltage V1 of photovoltaic string A is the maximum value among the output voltages of each photovoltaic string 10, so Vbus = V1.

[0039] It is understood that the photovoltaic module 11 includes multiple photovoltaic panels, and the number and connection method of the photovoltaic panels can be set according to the actual situation, without specific limitations here. The optimizer 12 can be a power optimizer with maximum power point tracking function. The inverter circuit 20 can be any circuit with DC-to-AC function, such as a dual active bridge (DAB) inverter circuit, without specific limitations here. The load is, for example, a household AC load or the power grid. When the load is the power grid, the photovoltaic power can be fed into the power grid through the inverter circuit 20, provided that the inverter circuit 20 is allowed to feed power.

[0040] Additionally, please refer to... Figure 1 The photovoltaic system 100 also includes a controller 30. For example... Figure 1 As shown by the dashed lines, the controller 30 is electrically connected to the optimizer 12 in each photovoltaic string 10 and is used to control the operation of the optimizer 12. The controller 30 may be, for example, a microcontroller unit (MCU) or other control circuit. In some embodiments, the controller 30 may be a standalone controller. In other embodiments, the controller 30 may also be the controller of the inverter circuit 20, electrically connected to the inverter circuit 20 and used to control the operation of the inverter circuit 20. The controller 30 may be integrated independently or as part of the inverter circuit 20; this is not limited here.

[0041] In some implementations, the controller 30 can send commands to the optimizer 12 via power line communication (PLC) to control the startup and voltage output of the optimizer 12. Of course, other common communication methods can also be used between the controller 30 and the optimizer 12, and it is not limited to the PLC method.

[0042] In some embodiments, each optimizer 12 has a unique optimizer identifier, which is used to characterize the optimizer 12. Based on the optimizer identifier, the controller 30 can accurately control the optimizer 12 characterized by the optimizer identifier.

[0043] The optimizer identifier can be composed of letters, Arabic numerals, Chinese characters, Roman numerals, and / or other characters or identifiers, according to a set rule or format. The optimizer identifier can be a single character or a string; this application does not specifically limit this. In one specific example, the optimizer identifier can be a product serial number. The product serial number can be a serial number (also called SN code) defined by the manufacturer according to product-related specifications. The optimizer 12 pre-stores the optimizer identifier and reports it to the controller 30 upon startup. In another example, the optimizer identifier can be the address of the optimizer 12. In yet another example, the optimizer identifier can be an optimizer name, optimizer number, or code defined by the user on a remote device (such as a host computer, mobile phone, or other mobile terminal). The remote device can establish a wireless communication connection with the controller 30 to send the optimizer identifier to the controller 30, and the controller 30 can store the optimizer identifier in internal or external memory.

[0044] In addition, the controller 30 also automatically identifies the topological relationship of the photovoltaic string 10 in the photovoltaic system 100 by executing the optimizer identification method provided in the embodiments of this application, which is beneficial to the control accuracy and control efficiency of the optimizer.

[0045] Figure 2 A flowchart of an optimizer identification method provided in an embodiment of this application is shown.

[0046] like Figure 2 As shown, the optimizer identification method may include the following steps: Step S11: Control the preset number of first optimizers to start with the corresponding first set output voltage.

[0047] The first optimizer is a subset of the optimizers in the photovoltaic system, and the output voltage of the first optimizer after startup is the corresponding first set output voltage.

[0048] The initial output voltage setting can be adjusted according to actual conditions, and no specific limit is set here.

[0049] The preset number is, for example, 2, 3 or more, and can be set according to the actual situation; no limit is imposed here. Different first optimizers correspond to different first set voltages. Therefore, when at least two first optimizers are activated, these first optimizers each have a unique and distinguishable output voltage.

[0050] Step S12: When the first optimizer starts, the first bus voltage of the DC bus is obtained, and the photovoltaic string affiliation of each first optimizer is determined according to the first bus voltage and the first set output voltage.

[0051] Understandably, each photovoltaic string is connected in parallel to the DC bus. Therefore, when the first optimizer in the photovoltaic string starts up, the first bus voltage on the DC bus is equivalent to the voltage response when the first optimizer starts up. The controller can obtain the first bus voltage by sampling the DC bus voltage in real time through a voltage sampling circuit.

[0052] The photovoltaic string affiliation of each first optimizer refers to which photovoltaic string each first optimizer belongs to.

[0053] Understandably, optimizers within the same photovoltaic string are connected in series, and series-connected optimizers exhibit a linear superposition of output voltages. Optimizers in different photovoltaic strings are connected in parallel, and parallel-connected optimizers exhibit the characteristic of maximizing the output voltage. Therefore, when there are two or more first optimizers, the output voltage of each first optimizer and its photovoltaic string affiliation jointly determine the first bus voltage Vbus1 on the DC bus. Moreover, since different first optimizers correspond to different first set output voltages, different first optimizers generate different output voltages, allowing the DC bus to generate a corresponding, specific first bus voltage under the photovoltaic string affiliation of each first optimizer. In other words, there is a correspondence between the first bus voltage, the photovoltaic string affiliation of each first optimizer, and the first set output voltage. Therefore, in step S12, the controller can deduce the photovoltaic string affiliation of the first optimizer based on the first bus voltage and the first set output voltage of the first optimizer.

[0054] Step S13: Based on the photovoltaic string affiliation relationship of at least one first optimizer, control each second optimizer to start sequentially with the corresponding second set output voltage.

[0055] The second optimizer refers to all optimizers in the photovoltaic system other than the first optimizer. The output voltage of the second optimizer after startup is the corresponding second preset output voltage. The magnitude of the second preset output voltage can be set according to actual conditions; the second preset output voltages for each second optimizer can be the same or different, and no specific limitation is made here.

[0056] In step S13, the controller can control each second optimizer to start sequentially according to a set detection order. The detection order can be the sorting of optimizer identifiers or a user-defined order, which is not specifically limited here. Furthermore, during the startup control process of each second optimizer, the controller can control the startup of the second optimizer based on the photovoltaic string affiliation relationship of at least one first optimizer, while simultaneously controlling the startup of some or all of the first optimizers.

[0057] For example, when starting the first second optimizer: If each first optimizer belongs to the same photovoltaic string, the controller can control the first second optimizer and each first optimizer to start simultaneously.

[0058] If each first optimizer belongs to a different photovoltaic string, the controller can control the first second optimizer to start simultaneously with the first optimizer in one of the photovoltaic strings. Understandably, after starting the first second optimizer, the controller can proceed to steps S14 and S15 to determine the photovoltaic string affiliation of the first second optimizer. In some scenarios, the controller can also control the first second optimizer to start simultaneously with the first optimizers in different photovoltaic strings multiple times, and proceed to steps S14 and S15 multiple times.

[0059] When starting the next second optimizer: If each first optimizer and the previously started second optimizer belong to the same photovoltaic string, the controller can control each first optimizer, the previously started second optimizer, and the next second optimizer to start simultaneously.

[0060] If the previously activated second optimizers and each of the first optimizers belong to different photovoltaic strings, the controller can control the next second optimizer to start simultaneously with either the first or second optimizer in one of these photovoltaic strings. Understandably, after starting the next second optimizer, the controller can proceed to steps S14 and S15 to determine the photovoltaic string affiliation of the next second optimizer. In some scenarios, the controller can also control the next second optimizer to start simultaneously with either the first or second optimizer in different photovoltaic strings multiple times, and proceed to steps S14 and S15 multiple times.

[0061] This process continues until the startup control of the last second optimizer is completed.

[0062] Step S14: When the second optimizer starts, obtain the second bus voltage of the DC bus.

[0063] Understandably, when the second optimizer in the photovoltaic string starts up, the second bus voltage on the DC bus is equivalent to the voltage response when the second optimizer starts up. The controller can obtain the second bus voltage by sampling the DC bus voltage in real time through the voltage sampling circuit.

[0064] Step S15: Based on the second bus voltage, the first set output voltage, the second set output voltage, and the photovoltaic string affiliation relationship of the first optimizer, determine the photovoltaic string affiliation relationship of the second optimizer.

[0065] Understandably, optimizers within the same photovoltaic string exhibit a linear superposition of output voltages, while optimizers in different photovoltaic strings have the characteristic of maximizing their output voltage. Therefore, when the second optimizer and the first optimizer belong to the same photovoltaic string, or to different photovoltaic strings, the DC bus will generate corresponding, different second bus voltages. In other words, the second bus voltage corresponds to the photovoltaic string affiliation of each first optimizer, the first set output voltage, and the second set output voltage.

[0066] Therefore, in step S15, the controller can deduce the photovoltaic string affiliation of the second optimizer based on the second bus voltage, the first set output voltage, the second set output voltage, and the photovoltaic string affiliation of the first optimizer.

[0067] Step S16: Based on the photovoltaic string affiliation relationship of the first optimizer and the photovoltaic string affiliation relationship of the second optimizer, obtain the topological relationship of each photovoltaic string in the photovoltaic system.

[0068] Understandably, the controller can calculate the number of photovoltaic strings in parallel and the number of optimizers connected in series on each photovoltaic string based on the photovoltaic string affiliation relationship of the first optimizer and the photovoltaic string affiliation relationship of the second optimizer, thereby obtaining the topological relationship of each photovoltaic string in the photovoltaic system.

[0069] In summary, in the optimizer identification method of this application embodiment, a preset number of first optimizers are first controlled to start with corresponding first set output voltages, and the first bus voltage of the DC bus is acquired when the first optimizer starts. Since the first set output voltages of different first optimizers are different, the DC bus can generate corresponding and specific first bus voltages based on the first set output voltages of the first optimizers and the photovoltaic string affiliation relationship. Therefore, after acquiring the first bus voltage, the photovoltaic string affiliation relationship of each first optimizer can be determined according to the first bus voltage and the first set output voltage. Then, based on the photovoltaic string affiliation relationship of at least one first optimizer, each second optimizer is controlled to start sequentially with corresponding second set output voltages, and the second bus voltage of the DC bus is acquired when the second optimizer starts. Since the DC bus generates different second bus voltages depending on whether the second optimizer and the first optimizer belong to the same or different photovoltaic strings, after obtaining the second bus voltage, the photovoltaic string affiliation of the second optimizer can be determined based on the second bus voltage, the first set output voltage, the second set output voltage, and the photovoltaic string affiliation of the first optimizer. Finally, the topology of each photovoltaic string in the photovoltaic system can be obtained based on the photovoltaic string affiliation of the first and second optimizers. Therefore, the optimizer identification method of this application can intelligently identify the topology of photovoltaic strings in a photovoltaic system, saving time and effort, quickly obtaining accurate photovoltaic string topology, avoiding errors, facilitating accurate optimizer control, and simplifying photovoltaic string inspection, maintenance, and expansion. This helps improve the intelligence, safety, operation and maintenance efficiency, and adaptability of the photovoltaic system.

[0070] Moreover, the optimizer identification method in this application embodiment is very simple, does not require additional hardware identification circuits, and does not require labor costs, so it will not increase the application cost of the photovoltaic system.

[0071] In the embodiments of this application, the first set output voltage of each first optimizer will not be repeated. When the preset number is at least two, the summation result of the first set output voltage of any plurality of first optimizers will also not be repeated.

[0072] In some embodiments, the value of the first set output voltage corresponding to each first optimizer is a prime number and is unique, and the sum of the first set output voltages after any combination of the first optimizers is unique. It is understood that a prime number is a natural number greater than 1 that is only divisible by 1 and itself, such as 2, 3, 5, 7, 11, 13, 17, 19, 23, etc. Setting the first set output voltage to a prime number ensures its uniqueness.

[0073] Therefore, regardless of the photovoltaic string affiliation of each first optimizer, that is, regardless of whether the first optimizers are connected in parallel or in series, the first bus voltage Vbus1 generated based on the first set output voltage of the first optimizer and the photovoltaic string affiliation is always unique when the first optimizer starts.

[0074] Based on this, in step S12, the controller can accurately determine the photovoltaic string affiliation of each first optimizer according to the first bus voltage and the first set output voltage, avoiding confusion and misjudgment caused by the same first set output voltage or the same summation result of the first set output voltage. Moreover, the controller can realize the parallel detection of at least two first optimizers, thus improving the optimizer detection efficiency.

[0075] Specifically, step S12, which involves determining the affiliation of at least one first optimizer with the first photovoltaic string based on the first bus voltage and the set output voltage, may include: If the first bus voltage is equal to the maximum value among the first set output voltages corresponding to each first optimizer, then each first optimizer is determined to belong to a different photovoltaic string.

[0076] If the voltage of the first bus is equal to the sum of the first set output voltages corresponding to at least two first optimizers, then it is determined that at least two first optimizers belong to the same photovoltaic string.

[0077] In other words, when the first bus voltage is the maximum value among the first set output voltages, it means that the first bus voltage conforms to the characteristic of the voltage taking the maximum value in a parallel circuit. At this time, each first optimizer is in parallel, so it can be determined that each first optimizer belongs to a different photovoltaic string.

[0078] When the first bus voltage is the sum of the first set output voltage, it means that the first bus voltage conforms to the characteristic of linear voltage superposition of a series circuit. At this time, each first optimizer is in series, so it can be determined that each first optimizer belongs to the same photovoltaic string.

[0079] To better understand, step S12 is illustrated below using three first optimizers as examples.

[0080] In this example, the three first optimizers are: first optimizer a, first optimizer b, and first optimizer c. The first set output voltage values ​​of these three first optimizers are different prime numbers, and the sum of the first set output voltages corresponding to any two first optimizers is greater than the first set output voltage corresponding to the remaining first optimizer. For example, first optimizer a corresponds to a first set output voltage of 7V, first optimizer b corresponds to a first set output voltage of 11V, and first optimizer c corresponds to a first set output voltage of 13V.

[0081] When the first optimizers a, b, and c start with their corresponding first set output voltages: Case 1: If the voltage of the first bus is Vbus1 = 31V, that is, Vbus1 = 7V + 11V + 13V, then the first optimizers a, b, and c belong to the same photovoltaic string and are connected in series.

[0082] Case 2: If the first bus voltage Vbus1 = 13V, that is, the first bus voltage is equal to the maximum value of the output voltages of the first optimizers a, b, and c, then these three first optimizers are determined to belong to different photovoltaic strings and form a parallel relationship.

[0083] Case 3: If the voltage of the first bus is Vbus1 = 18V, that is, Vbus1 = 7V + 11V, then the first optimizers a and b belong to the same photovoltaic string and are connected in series; the first optimizer c belongs to another photovoltaic string and is connected in parallel with the first optimizers a and b.

[0084] Case 4: If the voltage of the first bus is Vbus1 = 20V, that is, Vbus1 = 7V + 13V, then the first optimizers a and c belong to the same photovoltaic string and are connected in series; the first optimizer b belongs to another photovoltaic string and is connected in parallel with the first optimizers a and c.

[0085] Case 5: If the voltage of the first bus is Vbus1 = 24V, that is, Vbus1 = 11V + 13V, then the first optimizers b and c belong to the same photovoltaic string and are connected in series; the first optimizer a belongs to another photovoltaic string and is connected in parallel with the first optimizers b and c.

[0086] Therefore, when the number of first optimizers is three, step 12 can specifically include: When the first bus voltage equals the sum of the first set output voltages corresponding to the three first optimizers, it is determined that the three first optimizers belong to the same photovoltaic string.

[0087] When the voltage of the first bus is equal to the sum of the first set output voltages corresponding to any two first optimizers, the two corresponding first optimizers are determined to belong to the same photovoltaic string, and the remaining first optimizers are assigned to another photovoltaic string.

[0088] When the first bus voltage is equal to the maximum value among the first set output voltages corresponding to each first optimizer, the three first optimizers are determined to belong to different photovoltaic strings.

[0089] In summary, based on the uniqueness of the first set output voltage and the uniqueness of the sum of the first set output voltages, a unique first bus voltage corresponding to the photovoltaic string affiliation of the first optimizer can be generated on the DC bus when the first optimizer starts. The controller can then quickly identify which photovoltaic string the first optimizer is located in based on the linear relationship between the first bus voltage and the first set output voltage, thus obtaining an accurate photovoltaic string affiliation for the first optimizer. This is also beneficial when subsequently using the photovoltaic string affiliation of the first optimizer to determine the photovoltaic string affiliation of the second optimizer, thereby obtaining an accurate photovoltaic string affiliation for the second optimizer.

[0090] In one embodiment, if each first optimizer belongs to a different photovoltaic string: Then please see Figure 3 The process of determining the photovoltaic string affiliation of the second optimizer each time the second optimizer is started, based on the second bus voltage, the second set output voltage, and the photovoltaic string affiliation of the first optimizer (i.e., step S15), may include the following steps: Step S151: Under the photovoltaic string affiliation relationship of the first optimizer, obtain the sum of the second set output voltage and any one of the first set output voltages.

[0091] Specifically, the controller can iteratively sum the second set output voltage corresponding to the currently activated second optimizer with the first set output voltage corresponding to a first optimizer on different photovoltaic strings, thus obtaining multiple summation results. Each first optimizer on each photovoltaic string corresponds to a different summation result.

[0092] Understandably, if the currently activated second optimizer is connected in series to one of the photovoltaic strings to which one of the first optimizers belongs, then the second bus voltage will be equal to the sum of the second set output voltage and the first set output voltage of one of the first optimizers. If the currently activated second optimizer and each of the first optimizers are connected in parallel to different photovoltaic strings, then the second bus voltage will not be equal to the sum of the second set output voltage and the first set output voltage of one of the first optimizers. Therefore, obtaining the sum of the second set output voltage and any one of the first set output voltages in step S151 can facilitate the subsequent deduction of the photovoltaic string affiliation relationship of the second optimizer based on the summation result.

[0093] Step S152: Determine whether the second bus voltage is equal to the sum of the second set output voltage and the first set output voltage corresponding to one of the activated first optimizers.

[0094] Understandably, the controller can compare the second bus voltage with each summation result. If the second bus voltage equals one of the summation results, then proceed to step S153. Otherwise, proceed to step S154.

[0095] Step S153: Determine that the second optimizer and the corresponding first optimizer are located in the same photovoltaic string.

[0096] In other words, when the second bus voltage is equal to the sum of the second set output voltage and the first set output voltage corresponding to one of the started first optimizers, it indicates that the second bus voltage conforms to the characteristic of linear voltage superposition in a series circuit. Therefore, it is determined that the currently started second optimizer and one of the first optimizers are located in the same photovoltaic string.

[0097] Step S154: Determine that the second optimizer and any one of the first optimizers are not in the same photovoltaic string.

[0098] In other words, when the second bus voltage is not equal to the sum of the second set output voltage and the first set output voltage corresponding to any of the first optimized units that are started, it indicates that the second bus voltage does not conform to the characteristic of linear voltage superposition in a series circuit. Therefore, it is determined that the currently started second optimized unit and any of the first optimized units are not in the same photovoltaic string, that is, the currently started second optimized unit is located in another photovoltaic string.

[0099] In another embodiment, if at least some of the first optimizers belong to the same photovoltaic string, for example, all the first optimizers belong to the same photovoltaic string, or for example, at least two first optimizers belong to the same photovoltaic string, and the remaining first optimizers are not in this photovoltaic string: Therefore, the process of determining the photovoltaic string affiliation of the second optimizer (i.e., step S15) based on the second bus voltage, the second set output voltage, and the photovoltaic string affiliation of the first optimizer each time the second optimizer is started may include the following steps: The first step is to obtain the sum of the second set output voltage and the first set output voltage corresponding to the first optimizer on any photovoltaic string, under the photovoltaic string affiliation relationship of the first optimizer.

[0100] Understandably, the controller can iterate through the second set output voltage corresponding to the currently activated second optimizer and sum it sequentially with the first set output voltage corresponding to all the first optimizers on different photovoltaic strings, thus obtaining multiple summation results. Each photovoltaic string corresponds to a different summation result.

[0101] The second step is to determine whether the second bus voltage is equal to the sum of the second set output voltage and the first set output voltage corresponding to the first optimizer on one of the photovoltaic strings.

[0102] If so, it means that the voltage of the second bus conforms to the characteristic of linear superposition of voltages in a series circuit. Therefore, it is determined that the currently started second optimizer and the first optimizer on one of the photovoltaic strings are located in the same photovoltaic string.

[0103] Otherwise, it indicates that the voltage of the second bus does not conform to the characteristic of linear voltage superposition in a series circuit. Therefore, it is determined that the currently started second optimizer and the first optimizer on one of the photovoltaic strings are not in the same photovoltaic string, that is, the currently started second optimizer is located in another photovoltaic string.

[0104] To better understand, step S15 is described below as an example.

[0105] Continuing with the previous examples of first optimizer a, first optimizer b, and first optimizer c. Assume that first optimizer a corresponds to a first set output voltage of 7V, first optimizer b corresponds to a first set output voltage of 11V, first optimizer c corresponds to a first set output voltage of 13V, and second optimizer d corresponds to a second set output voltage of 7V. The photovoltaic system includes three photovoltaic strings.

[0106] In scenario 1, the first optimizers a, b, and c are all located in photovoltaic string A, and Vbus1 = 7V + 11V + 13V = 31V: Case 1.1: The first optimizer a, b, c and the second optimizer d start at the same time. If the second bus voltage Vbus2 = 38V, that is, Vbus2 = 31V + 7V, then the second optimizer d is located in the photovoltaic string A where the first optimizers a, b, c are located.

[0107] Case 1.2: The first optimizer a, b, c and the second optimizer d start at the same time. If the second bus voltage Vbus2 = 31V, that is, Vbus2 = 31V, then it is determined that the second optimizer d is not in photovoltaic string A. The second optimizer d is located in other photovoltaic strings, such as photovoltaic strings B or C.

[0108] Understandably, "PV string A," "PV string B," and "PV string C" are illustrative names used only to facilitate the distinction between the three different PV strings. Any PV string can be called PV string A, PV string B, or PV string C.

[0109] Scenario 2: First optimizer a is located in photovoltaic string A, first optimizer b is located in photovoltaic string B, and first optimizer c is located in photovoltaic string C, with Vbus1 = 13V: Case 2.1: The first optimizer a and the second optimizer d start at the same time. If the second bus voltage Vbus2 = 14V, that is, Vbus2 = 7V + 7V, then the second optimizer d is located in the photovoltaic string A where the first optimizer a is located.

[0110] Case 2.2: The first optimizer a and the second optimizer d start simultaneously. If the second bus voltage Vbus2 = 7V, then it is determined that the second optimizer d is not located in photovoltaic string A where the first optimizer a is located. The second optimizer d is located in another photovoltaic string, which may be photovoltaic string B or C.

[0111] To identify whether the second optimizer d is located in photovoltaic string B or C, we can proceed to case 2.3 to continue the judgment.

[0112] Case 2.3: The first optimizer b and the second optimizer d start simultaneously. If the second bus voltage Vbus2 = 18V, that is, Vbus2 = 11V + 7V, then the second optimizer d is located in the photovoltaic string B where the first optimizer b is located.

[0113] Case 2.4: The first optimizer b and the second optimizer d start simultaneously. If the second bus voltage Vbus2 = 11V, then it is determined that the second optimizer d is not located in the photovoltaic string B where the first optimizer b is located. Therefore, it is determined that the second optimizer d is located in the photovoltaic string C.

[0114] In scenario 3, where the first optimizers a and b are both located in photovoltaic string A, and the first optimizer c is located in photovoltaic string B, and Vbus1 = 7V + 11V = 18V: Case 3.1: If the second bus voltage Vbus2 = 25V, that is, Vbus2 = 7V + 11V + 7V, then the second optimizer d is located in the photovoltaic string A where the first optimizers a and b are located.

[0115] Case 3.2: If the second bus voltage Vbus2 = 18V, that is, Vbus2 = 7V + 11V, then the second optimizer d is not in photovoltaic string A where the first optimizers a and b are located, nor in photovoltaic string C where the first optimizer c is located. Therefore, the second optimizer d is located in photovoltaic string B.

[0116] Case 3.3: If the second bus voltage Vbus2 = 20V, that is, Vbus2 = 13V + 7V, then the second optimizer d is located in the photovoltaic string C where the first optimizer c is located.

[0117] Understandably, after determining the photovoltaic string affiliation of each second optimizer, the controller can activate the next second optimizer and re-execute step S15 to determine the photovoltaic string affiliation of the next second optimizer. During this process, the already detected second optimizers can be considered as first optimizers. Therefore, the process for determining the photovoltaic string affiliation of the next second optimizer can be referred to the above description and will not be repeated here.

[0118] In summary, based on the uniqueness of the first set output voltage and the uniqueness of the sum of the first set output voltages, the DC bus can generate a unique second bus voltage corresponding to the photovoltaic string affiliation of the second optimizer when the second optimizer starts. The controller can then quickly identify which photovoltaic string the second optimizer is located in based on the linear relationship between the second bus voltage, the first set output voltage, and the second set output voltage, thus obtaining an accurate photovoltaic string affiliation for the second optimizer. This is beneficial for obtaining an accurate photovoltaic string topology when subsequently determining the overall topology of the photovoltaic strings using the photovoltaic string affiliation relationships of the first and second optimizers.

[0119] Understandably, after obtaining the topology of each photovoltaic string in the photovoltaic system (i.e., step S16), the controller can also perform balanced control on each photovoltaic string based on the topology of the photovoltaic strings.

[0120] For details, please refer to Figure 4 Optimizer identification methods also include: Step S21: Based on the set target bus voltage and the topology of each photovoltaic string, determine the target output voltage of each optimizer corresponding to each photovoltaic string.

[0121] The target bus voltage Vtarget can be set according to the operating requirements of the inverter circuit, and no specific limitation is made here.

[0122] The topology of each photovoltaic (PV) string includes the number of PV strings connected in parallel and the number of optimizers connected in series for each PV string. Therefore, the controller can assign a suitable target output voltage to the optimizer of each PV string based on the target bus voltage, the number of PV strings connected in parallel, and the number of optimizers connected in series for each PV string.

[0123] The target output voltage of each photovoltaic string is negatively correlated with the number of optimizers connected in series.

[0124] In one embodiment, the target output voltage Vself of each photovoltaic string is inversely proportional to the number N of its optimizers connected in series, and the calculation formula can be as follows: Vself = Vtarget / N For example, suppose a photovoltaic system has three photovoltaic strings, with optimizers connected in series with 8, 7 and 6 units respectively, and the target bus voltage Vtarget is 400V.

[0125] The controller can first identify that the photovoltaic system has three photovoltaic strings through the aforementioned steps S11~S16, and the number of optimizers connected in series for the three photovoltaic strings are 8, 7 and 6 respectively. Then, the controller can allocate the target output voltage through the above calculation formula.

[0126] For a photovoltaic string containing 8 optimizers, the target output voltage of each optimizer is 400V / 8=50V.

[0127] For a single photovoltaic string containing 7 optimizers, the target output voltage of each optimizer is: 400V / 7≈ 57.14V.

[0128] For a single photovoltaic string containing 6 optimizers, the target output voltage of each optimizer is: 400V / 6≈ 66.66V.

[0129] Step S22: Control the operation of each optimizer according to the target output voltage of each optimizer.

[0130] Under the control of the controller, each optimizer outputs the corresponding target output voltage, and the output voltage of each photovoltaic string is equal to the sum of the target output voltages of all optimizers on that photovoltaic string, that is, all of them are the target bus voltage.

[0131] Therefore, through the steps S21-S22 described above, the output voltage of the optimizer can be adaptively adjusted according to the topology of the photovoltaic strings, achieving balanced control of the output voltage of each photovoltaic string. This design avoids circulating currents between photovoltaic strings and ensures that the actual output voltage of each photovoltaic string is within the inverter's withstand voltage range, preventing damage to the optimizer and inverter. It also enables precise voltage allocation for the optimizer, which is beneficial for maximizing the power generation efficiency of the photovoltaic system.

[0132] In some embodiments, please refer to Figure 5 Before controlling the first optimizer to start with the corresponding first set output voltage (i.e., step S11), the optimizer identification method further includes: Step S31: Obtain the optimizer identifier of each optimizer and control each optimizer to be in standby mode.

[0133] For example, after detecting that all optimizers are online (i.e., after establishing communication connections with each optimizer), the controller can obtain the optimizer identifier of each optimizer from each optimizer, a remote device, or a storage medium. Based on the optimizer identifier, the controller can then put the optimizer corresponding to that identifier into a standby state. Optimizers in standby state do not output voltage.

[0134] Step S32: Obtain the detection order of each optimizer according to the size relationship of the optimizer identifiers, and take the preset number of optimizers detected first as the first optimizer, and take the remaining optimizers detected later than the first optimizer as the second optimizer.

[0135] For example, the controller can use the optimizer identifiers arranged in descending order as the detection order, or the optimizer identifiers arranged in ascending order as the detection order. Then, it identifies the first preset number of optimizers detected in the detection order as the first optimizer, and the remaining optimizers are the second optimizers. After that, the controller can execute steps S11~S16 to identify the photovoltaic string affiliation relationship between the first optimizer and the second optimizer.

[0136] Based on this design, errors in the first and second bus voltages caused by the premature start of the optimizer before identifying the photovoltaic string affiliation of the optimizer can be avoided, which would affect the accuracy of identifying the photovoltaic string affiliation of the first and second optimizers. Furthermore, unnecessary power consumption can be reduced.

[0137] It should be noted that, for the sake of simplicity, the aforementioned method embodiments are described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, because according to this application, some steps may be performed in other orders or simultaneously.

[0138] Please see Figure 6 The diagram shows a structural schematic of an electronic device provided in an embodiment of this application.

[0139] like Figure 6 As shown, the electronic device 200 may include a processor 201 and a memory 202.

[0140] Processor 201 can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. General-purpose processors can be microprocessors or any conventional processors, etc.

[0141] The memory 202 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed discs, laser discs, optical discs, digital universal discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. The memory 202 may exist independently and be connected to the processor 201 via a bus. The memory 202 may also be integrated with the processor 201.

[0142] The memory 202 stores programs, instructions, or code for executing the optimizer identification method described above. The processor 201 executes the programs, instructions, or code stored in the memory 202. The programs, instructions, or code stored in the memory 202 can execute some or all of the steps in the aforementioned optimizer identification method embodiments.

[0143] Please see Figure 7 The diagram illustrates an optimizer identification device provided in an embodiment of this application. This optimizer identification device can be used to implement the aforementioned optimizer identification method.

[0144] Specifically, such as Figure 7As shown, the optimizer identification device 300 includes: a first control module 301, a first determination module 302, a second control module 303, an acquisition module 304, a second determination module 305, and a third determination module 306.

[0145] The first control module 301 is used to control a preset number of first optimizers to start with a corresponding first set output voltage; wherein, different first optimizers correspond to different first set voltages.

[0146] The first determining module 302 is used to obtain the first bus voltage of the DC bus when the first optimizer starts, and determine the photovoltaic string affiliation of each first optimizer based on the first bus voltage and the first set output voltage.

[0147] The second control module 303 is used to control each second optimizer to start sequentially with a corresponding second set output voltage based on the photovoltaic string affiliation relationship of at least one first optimizer; the second optimizer is the other optimizers in the photovoltaic system other than the first optimizer.

[0148] The acquisition module 304 is used to acquire the second bus voltage of the DC bus when the second optimizer is started.

[0149] The second determining module 305 is used to determine the photovoltaic string affiliation of the second optimizer based on the second bus voltage, the first set output voltage, the second set output voltage, and the photovoltaic string affiliation of the first optimizer.

[0150] The third determining module 306 is used to obtain the topological relationship of each photovoltaic string in the photovoltaic system based on the photovoltaic string affiliation relationship of the first optimizer and the photovoltaic string affiliation relationship of the second optimizer.

[0151] It is understood that the division of the various modules in the optimizer identification device 300 described above is only for illustrative purposes. In other embodiments, the optimizer identification device 300 can be divided into different modules as needed to complete all or part of the functions of the optimizer identification device 300 described above.

[0152] The specific implementation of each module in the embodiments of this application can also refer to the corresponding description of the aforementioned optimizer identification method embodiments, so it will not be described in detail here.

[0153] In the various embodiments of this application, all functional modules can be integrated into one processing module / unit, or each module can be a separate module, or two or more modules can be integrated into one module; the integrated module can be implemented in hardware or in the form of hardware plus software functional modules.

[0154] If the integrated modules described above in this application are implemented as software functional modules and sold or used as independent products, they can also be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, or the parts that contribute to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as mobile storage devices, ROM, RAM, magnetic disks, or optical disks.

[0155] This application also provides a computer-readable storage medium for storing a computer program, which, when executed by a controller, causes the controller to implement all or part of the steps described in the aforementioned optimizer identification method embodiments. The computer-readable storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Specific implementations of the computer-readable storage medium can be found in the aforementioned description of the memory, and will not be repeated here.

[0156] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application.

Claims

1. An optimizer identification method, characterized in that, The method is applied to a photovoltaic system, which includes an inverter circuit and at least two photovoltaic strings. Each photovoltaic string includes multiple photovoltaic modules and multiple optimizers. The output terminal of each photovoltaic module is connected to the input terminal of the corresponding optimizer. The output terminals of the optimizers in each photovoltaic string are connected in series and then connected to the inverter circuit via a DC bus. A preset number of first optimizers are activated with a corresponding first set output voltage; wherein, different first optimizers correspond to different first set voltages; When the first optimizer starts, the first bus voltage of the DC bus is obtained, and the photovoltaic string affiliation of each first optimizer is determined according to the first bus voltage and the first set output voltage. Based on the photovoltaic string affiliation relationship of at least one of the first optimizers, each of the second optimizers is controlled to start sequentially with a corresponding second set output voltage; the second optimizers are the other optimizers in the photovoltaic system besides the first optimizer. When the second optimizer starts, the second bus voltage of the DC bus is acquired; Based on the second bus voltage, the first set output voltage, the second set output voltage, and the photovoltaic string affiliation of the first optimizer, the photovoltaic string affiliation of the second optimizer is determined. Based on the photovoltaic string affiliation relationships of the first optimizer and the second optimizer, the topological relationships of each photovoltaic string in the photovoltaic system are obtained.

2. The method as described in claim 1, characterized in that, The preset number of the first optimizers is at least two; the value of the first set output voltage corresponding to each of the first optimizers is a prime number and unique, and the summation result of the first set output voltage after any combination of the first optimizers is unique.

3. The method as described in claim 2, characterized in that, The step of determining the photovoltaic string affiliation of each of the first optimizers based on the first bus voltage and the first set output voltage includes: If the first bus voltage is equal to the maximum value among the first set output voltages corresponding to each of the first optimizers, then each of the first optimizers is determined to belong to a different photovoltaic string. Alternatively, if the first bus voltage is equal to the sum of the first set output voltages corresponding to at least two of the first optimizers, then it is determined that at least two of the first optimizers belong to the same photovoltaic string.

4. The method as described in claim 2 or 3, characterized in that, The step of determining the photovoltaic string affiliation relationship of the second optimizer based on the second bus voltage, the first set output voltage, the second set output voltage, and the photovoltaic string affiliation relationship of the first optimizer includes: Under the photovoltaic string affiliation relationship of the first optimizer, obtain the sum of the second set output voltage and any one of the first set output voltages; If the second bus voltage is equal to the sum of the second set output voltage and the first set output voltage corresponding to one of the activated first optimizers, then it is determined that the second optimizer and the corresponding first optimizer are located in the same photovoltaic string; otherwise, it is determined that the second optimizer and any one of the first optimizers are not in the same photovoltaic string.

5. The method as described in claim 1, characterized in that, The preset number of the first optimizers is three, and the sum of the first set output voltages corresponding to any two of the first optimizers is greater than the first set output voltages corresponding to the remaining first optimizers. The step of determining the photovoltaic string affiliation of each of the first optimizers based on the first bus voltage and the first set output voltage includes: When the voltage of the first bus is equal to the sum of the first set output voltages corresponding to the three first optimizers, it is determined that the three first optimizers belong to the same photovoltaic string. When the voltage of the first bus is equal to the sum of the first set output voltages corresponding to any two of the first optimizers, it is determined that the two corresponding first optimizers belong to the same photovoltaic string, and the remaining first optimizers belong to another photovoltaic string. When the first bus voltage is equal to the maximum value among the first set output voltages corresponding to each of the first optimizers, it is determined that the three first optimizers belong to different photovoltaic strings.

6. The method according to any one of claims 1 to 5, characterized in that, The method further includes: Based on the set target bus voltage and the topology of each photovoltaic string, the target output voltage of each optimizer corresponding to each photovoltaic string is determined; The operation of each optimizer is controlled according to the target output voltage of each optimizer.

7. The method according to any one of claims 1 to 6, characterized in that, Before the first optimizer, which controls a preset number of operations, is activated with a corresponding first set output voltage, the method further includes: Obtain the optimizer identifier of each optimizer and control each optimizer to be in standby mode; The detection order of each optimizer is obtained according to the size relationship of the optimizer identifiers, and the preset number of optimizers detected first are designated as the first optimizer, and the remaining optimizers detected later than the first optimizer are designated as the second optimizer.

8. A photovoltaic system, characterized in that, The photovoltaic system includes an inverter circuit, a controller, and at least two photovoltaic strings. Each photovoltaic string includes multiple photovoltaic modules and multiple optimizers. The output terminal of each photovoltaic module is connected to the input terminal of the corresponding optimizer. The output terminals of the optimizers in each photovoltaic string are connected in series and then connected to the inverter circuit through a DC bus. The controller is used to execute the optimizer identification method as described in any one of claims 1 to 7.

9. An optimizer identification device, characterized in that, It includes a first control module, a first determination module, a second control module, an acquisition module, a second determination module, and a third determination module; The first control module is used to control a preset number of first optimizers to start with a corresponding first set output voltage; wherein, different first optimizers correspond to different first set voltages; The first determining module is used to obtain the first bus voltage of the DC bus when the first optimizer is started, and determine the photovoltaic string affiliation relationship of each of the first optimizers based on the first bus voltage and the first set output voltage. The second control module is used to control each second optimizer to start sequentially with a corresponding second set output voltage based on the photovoltaic string affiliation relationship of at least one of the first optimizers; the second optimizers are the other optimizers in the photovoltaic system other than the first optimizer; The acquisition module is used to acquire the second bus voltage of the DC bus when the second optimizer is started; The second determining module is used to determine the photovoltaic string affiliation of the second optimizer based on the second bus voltage, the first set output voltage, the second set output voltage, and the photovoltaic string affiliation of the first optimizer. The third determining module is used to obtain the topological relationship of each photovoltaic string in the photovoltaic system based on the photovoltaic string affiliation relationship of the first optimizer and the photovoltaic string affiliation relationship of the second optimizer.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by the controller, causes the controller to implement the optimizer identification method as described in any one of claims 1 to 7.

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