Power system and equipment searching method

Abstract

The invention provides a power system and a device searching method, and relates to the field of power. After a power converter broadcasts an information query request, a first direct-current controller receiving the information query request broadcasted by the power converter can forward the information query request in a direct-current string where the first direct-current controller is located; therefore, the second direct-current controller which does not normally receive the information query request broadcasted by the power converter can also receive the information query request, so that the information query request can be responded, and the power converter can search the second direct-current controller. Besides, direct current controllers which are not connected with the power converter are filtered out through communication quality limitation, so that the direct current controllers connected with other power converters are prevented from being determined as own direct current controllers, the accuracy of the direct current controllers which are determined through search operation and connected with the power converter is improved, and the reliability of the power converter is improved. And the control accuracy of the power converter on the direct current controller is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electric power, and in particular to an electric power system and a device searching method. BACKGROUND

[0002] The electric power system comprises a direct current controller and a power converter and the like components. The direct current controller and a photovoltaic assembly are connected in series, and a predictive current and voltage technology is adopted to ensure that the photovoltaic assembly is always in an optimal working state.

[0003] After the direct current controller and the power converter in the electric power system are installed, the power converter can automatically search for all the direct current controllers connected to the power converter. However, in actual scenarios, the accuracy of the direct current controllers connected to the determined power converter is low, which reduces the control accuracy of the power converter on the direct current controller. SUMMARY

[0004] In view of the above problems, the present application provides an electric power system and a device searching method to achieve the purpose of accurately searching for all the direct current controllers connected to the power converter. The specific scheme is as follows:

[0005] The first aspect of the present application provides an electric power system, comprising:

[0006] a power converter and at least one direct current assembly string;

[0007] The direct current assembly string comprises a plurality of direct current controllers, the input end of each direct current controller is used to be connected to a direct current source, and the output end of each direct current controller is connected in series to the input end of the power converter;

[0008] The power converter is used to broadcast an information query request;

[0009] The first direct current controller receiving the information query request broadcast by the power converter is used to, after receiving the information query request, respond to the information query request, feed back feedback information carrying the device identification information of the first direct current controller to the power converter, and forward the information query request within the direct current assembly string where the first direct current controller is located, so that the second direct current controller not receiving the information query request broadcast by the power converter feeds back feedback information carrying the device identification information of the second direct current controller to the power converter based on the forwarded information query request;

[0010] The power converter is also used to receive feedback information from each of the DC controllers; determine feedback information whose communication quality meets preset requirements from the received feedback information, and use it as target feedback information; record the device identification information in the target feedback information, so as to determine that the DC controller corresponding to the recorded device identification information is a DC controller that has a connection relationship with the power converter.

[0011] In one possible implementation, when the power converter is used to broadcast information query requests, it is specifically used for:

[0012] Determine the specified query sequence number and obtain the maximum timeout period;

[0013] Construct an information query request that includes the specified query sequence number and the maximum timeout period;

[0014] Activate the automatic search function and broadcast information query requests to communicable devices around the power converter;

[0015] When the first DC controller sends feedback information carrying the device identification information of the first DC controller to the power converter, it is specifically used for:

[0016] If it is determined that an information query request including the specified query number has been received and the device identification information of the device itself has been reported, the specified query number is marked to avoid reporting the device identification information of the device itself again.

[0017] If it determines that it has not received an information query request including the specified query number, or has received an information query request including the specified query number but has not reported its own device identification information, and if it wins the information reply permission, it will report its own device identification information to the power converter within the maximum timeout period.

[0018] In one possible implementation, when the power converter broadcasts an information query request to communicable devices around the power converter, it is specifically used for:

[0019] The information query request is sent to the magnetic ring connected to the communication module using its own communication module, so that the magnetic ring broadcasts the information query request to the communication link of the communicable devices around the power converter.

[0020] In one possible implementation, the power converter is also used for:

[0021] A device identification information list is determined; the device identification information list includes: device identification information of DC controllers that have been found to be connected to the power converter; the device identification information list can be continuously updated according to the search results of the power converter, and the initial content of the device identification information is empty;

[0022] When the power converter is used to construct an information query request including the specified query number and the maximum timeout time, it is specifically used for:

[0023] Construct an information query request that includes the specified query number, the maximum timeout time, and the device identification information list;

[0024] The first DC controller is used to determine that when it has received an information query request including the specified query number and has reported its own device identification information, it is specifically used to:

[0025] If the device identification information is found to be included in the device identification information list, it is determined that the device identification information has been received and reported by the device itself, including the specified query number.

[0026] In one possible implementation, the second DC controller is also used for:

[0027] After receiving the forwarded information query request, the information query request is forwarded within the DC string where the second DC controller is located;

[0028] When the second DC controller sends feedback information carrying the device identification information of the second DC controller to the power converter based on the forwarded information query request, it is specifically used for:

[0029] In response to the first information query request forwarded by the first DC controller and the first information query request forwarded by other second DC controllers, the system directly feeds back feedback information carrying the device identification information of the second DC controller to the power converter; or, it determines the first DC controller that forwards the information query request to the second DC controller and feeds back the feedback information carrying the device identification information of the second DC controller to the first DC controller, so that the first DC controller forwards the feedback information carrying the device identification information of the second DC controller to the power converter.

[0030] In one possible implementation, after the power converter determines that the DC controller corresponding to the recorded device identification information is a DC controller connected to the power converter, it is further configured to:

[0031] Add the device identification information of the DC controllers that are connected to the power converter found in this search to the device identification information list;

[0032] Reconstruct the information query request, including the specified query number, the maximum timeout, and the latest device identification information list, and broadcast the information query request again.

[0033] In one possible implementation, the feedback information also includes the signal strength of the communication link between the DC controller and the power converter;

[0034] The power converter is used to determine, from the received feedback information, the feedback information in which the communication quality meets the preset requirements, and as the target feedback information, specifically for:

[0035] Feedback information with signal strength greater than the signal strength threshold is used as target feedback information.

[0036] Alternatively, the feedback information may also include the signal strength and signal-to-noise ratio of the communication link between the DC controller and the power converter;

[0037] The power converter is used to determine, from the received feedback information, the feedback information in which the communication quality meets the preset requirements, and as the target feedback information, specifically for:

[0038] The link quality is calculated using the signal strength and the signal-to-noise ratio.

[0039] Determine the feedback information corresponding to link quality exceeding the link quality threshold, and use it as the target feedback information;

[0040] Alternatively, the feedback information may also include the link quality of the communication link between the DC controller and the power converter;

[0041] The power converter is used to determine, from the received feedback information, the feedback information in which the communication quality meets the preset requirements, and as the target feedback information, specifically for:

[0042] Determine the feedback information corresponding to link quality values ​​greater than the link quality threshold, and use this as the target feedback information.

[0043] A second aspect of this application provides a device search method that utilizes a power converter in a power system. The power system further includes at least one DC string, the DC string comprising multiple DC controllers, the input terminals of the DC controllers being connected to a DC source, and the output terminals of each DC controller being connected in series to the input terminal of the power converter.

[0044] The device search method includes:

[0045] The system broadcasts an information query request so that, upon receiving the information query request broadcast by the power converter, the first DC controller responds to the information query request by sending feedback information carrying the device identification information of the first DC controller to the power converter, and forwards the information query request within the DC string where the first DC controller is located, so that the second DC controller, which has not received the information query request broadcast by the power converter, sends feedback information carrying the device identification information of the second DC controller to the power converter based on the forwarded information query request;

[0046] Receive feedback information from each of the DC controllers;

[0047] From the feedback information received from each station, the feedback information whose communication quality meets the preset requirements is determined as the target feedback information;

[0048] Record the device identification information in the target feedback information to determine that the DC controller corresponding to the recorded device identification information is a DC controller that is connected to the power converter.

[0049] In one possible implementation, the broadcast information query request includes:

[0050] Determine the specified query sequence number and obtain the maximum timeout period;

[0051] Construct an information query request that includes the specified query sequence number and the maximum timeout period;

[0052] The automatic search function is activated, broadcasting information query requests to communicable devices around the power converter. If the DC converter determines that it has received an information query request including the specified query number and has already reported its own device identification information, it marks the specified query number to avoid reporting its own device identification information again. If it determines that it has not received an information query request including the specified query number, or has received an information query request including the specified query number but has not reported its own device identification information, and if it wins the information reply permission, it reports its own device identification information to the power converter within the maximum timeout period.

[0053] In one possible implementation, broadcasting the information query request to communicable devices around the power converter includes:

[0054] The information query request is sent to the magnetic ring connected to the communication module using its own communication module, so that the magnetic ring broadcasts the information query request to the communication link of the communicable devices around the power converter.

[0055] In one possible implementation, the device search method further includes:

[0056] A device identification information list is determined; the device identification information list includes: device identification information of DC controllers that have been found to be connected to the power converter; the device identification information list can be continuously updated according to the search results of the power converter, and the initial content of the device identification information is empty;

[0057] The construction of the information query request, which includes the specified query sequence number and the maximum timeout time, includes:

[0058] An information query request is constructed, including the specified query number, the maximum timeout time, and the device identification information list, so that when the DC controller determines that its own device identification information is included in the device identification information list, it can determine that it has received an information query request including the specified query number and has reported its own device identification information.

[0059] In one possible implementation, after determining that the DC controller corresponding to the recorded device identification information is a DC controller connected to the power converter, the device search method further includes:

[0060] Add the device identification information of the DC controllers that are connected to the power converter found in this search to the device identification information list;

[0061] The information query request is reconstructed, including the specified query sequence number, the maximum timeout time, and the latest device identification information list. The information query request is then broadcast again and executed sequentially.

[0062] In one possible implementation, the feedback information also includes the signal strength of the communication link between the DC controller and the power converter;

[0063] The step of determining, from the received feedback information, the feedback information whose communication quality meets the preset requirements and using it as the target feedback information includes:

[0064] Feedback information with signal strength greater than the signal strength threshold is used as target feedback information.

[0065] Alternatively, the feedback information may also include the signal strength and signal-to-noise ratio of the communication link between the DC controller and the power converter;

[0066] The step of determining, from the received feedback information, the feedback information whose communication quality meets the preset requirements and using it as the target feedback information includes:

[0067] The link quality is calculated using the signal strength and the signal-to-noise ratio.

[0068] Determine the feedback information corresponding to link quality exceeding the link quality threshold, and use it as the target feedback information;

[0069] Alternatively, the feedback information may also include the link quality of the communication link between the DC controller and the power converter;

[0070] The step of determining, from the received feedback information, the feedback information whose communication quality meets the preset requirements and using it as the target feedback information includes:

[0071] Determine the feedback information corresponding to link quality values ​​greater than the link quality threshold, and use this as the target feedback information.

[0072] A third aspect of this application provides a device search method, which uses any one of a plurality of DC controllers in at least one DC string in a power system, wherein the power system further includes a power converter, the input terminal of the DC controller is used to connect to a DC source, and the output terminal of each DC controller is connected in series to the input terminal of the power converter;

[0073] The device search method includes:

[0074] Receive the information query request broadcast by the power converter;

[0075] In the case of a first DC controller receiving an information query request broadcast by the power converter, after receiving the information query request, the controller responds to the information query request by sending feedback information carrying the device identification information of the first DC controller to the power converter, and forwards the information query request within the DC string where the first DC controller is located.

[0076] In the case where the second DC controller has not received the information query request broadcast by the power converter, based on the forwarded information query request, feedback information carrying the device identification information of the second DC controller is sent back to the power converter, so that the power converter receives the feedback information from each DC controller; from each received feedback information, feedback information whose communication quality meets the preset requirements is determined and used as the target feedback information; the device identification information in the target feedback information is recorded to determine that the DC controller corresponding to the recorded device identification information is: the DC controller that has a connection relationship with the power converter.

[0077] In one possible implementation, when the information query request includes the specified query number and the maximum timeout period, feedback information carrying the device identification information of the first DC controller is sent to the power converter, including:

[0078] If it is determined that an information query request including the specified query number has been received and the device identification information of the device itself has been reported, the specified query number is marked to avoid reporting the device identification information of the device itself again.

[0079] If it determines that it has not received an information query request including the specified query number, or has received an information query request including the specified query number but has not reported its own device identification information, and if it wins the information reply permission, it will report its own device identification information to the power converter within the maximum timeout period.

[0080] In one possible implementation, when the information query request includes the specified query number, the maximum timeout time, and the device identification information list, determining that the device identification information that has received the information query request including the specified query number and has been reported includes:

[0081] If the device identification information is found to be included in the device identification information list, it is determined that the device identification information has been received and reported by the device itself, including the specified query number.

[0082] In one possible implementation, in the case of a second DC controller that has not received an information query request broadcast by the power converter, the device search method further includes:

[0083] After receiving the forwarded information query request, the information query request is forwarded within the DC string where the second DC controller is located;

[0084] The information query request based on forwarding, and the feedback information carrying the device identification information of the second DC controller to the power converter, includes:

[0085] In response to the first information query request forwarded by the first DC controller and the first information query request forwarded by other second DC controllers, the system directly feeds back feedback information carrying the device identification information of the second DC controller to the power converter; or, it determines the first DC controller that forwards the information query request to the second DC controller and feeds back the feedback information carrying the device identification information of the second DC controller to the first DC controller, so that the first DC controller forwards the feedback information carrying the device identification information of the second DC controller to the power converter.

[0086] In one possible implementation, the feedback carrying device identification information of the first DC controller to the power converter includes:

[0087] Feedback information carrying the device identification information of the first DC controller and the signal strength of the communication link between the first DC controller and the power converter is sent to the power converter, so that the power converter takes the feedback information with a signal strength greater than the signal strength threshold as the target feedback information;

[0088] Alternatively, feedback information carrying the device identification information of the first DC controller, the signal strength and signal-to-noise ratio of the communication link between the first DC controller and the power converter is sent to the power converter, so that the power converter can use the signal strength and the signal-to-noise ratio to calculate the link quality, determine the feedback information corresponding to the link quality greater than the link quality threshold, and use it as the target feedback information;

[0089] Alternatively, feedback information carrying the device identification information of the first DC controller and the link quality of the communication link between the first DC controller and the power converter is sent to the power converter, so that the power converter determines the feedback information corresponding to the link quality greater than the link quality threshold and uses it as the target feedback information.

[0090] By employing the above technical solution, this application provides a power system and equipment search method. In this application, after a power converter broadcasts an information query request, the first DC controller that receives the information query request broadcast by the power converter can forward the information query request within its DC string. This allows the second DC controller, which did not normally receive the information query request broadcast by the power converter, to also receive the information query request and respond to it. This enables the power converter to search for the second DC controller, avoiding the problem of not finding the DC controller due to the second DC controller not normally receiving the information query request. Furthermore, from the received feedback information, feedback information whose communication quality meets preset requirements is determined and used as target feedback information. The device identification information in the target feedback information is recorded. Only the DC controller corresponding to the recorded device identification information is identified as a DC controller connected to the power converter. Communication quality limitations are used to filter out DC controllers not connected to the power converter, thereby preventing the identification of DC controllers connected to other power converters as the power converter's own DC controller. This improves the accuracy of identifying the DC controllers connected to the power converter through the search operation, and thus improves the control accuracy of the power converter over the DC controllers. Attached Figure Description

[0091] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.

[0092] Figure 1 A schematic diagram of the structure of a power system provided in this application;

[0093] Figure 2 This application provides a schematic diagram of the structure of a photovoltaic string.

[0094] Figure 3 A schematic diagram of another power system provided in this application;

[0095] Figure 4 A schematic diagram of another power system provided in this application;

[0096] Figure 5 An interactive schematic diagram of a device search method provided in this application;

[0097] Figure 6 A flowchart of a broadcast request provided in this application;

[0098] Figure 7 A schematic diagram illustrating a device search method provided in this application;

[0099] Figure 8 A flowchart of a device search method provided in this application;

[0100] Figure 9 A flowchart of another device search method provided in this application. Detailed Implementation

[0101] The embodiments of this application are described below with reference to the accompanying drawings. The terminology used in the implementation section of this application is for explaining specific embodiments only and is not intended to limit the scope of this application.

[0102] The embodiments of this application will now be described with reference to the accompanying drawings. Those skilled in the art will recognize that, with technological advancements and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are equally applicable to similar technical problems.

[0103] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms are interchangeable where appropriate; this is merely a way of distinguishing objects with the same attributes in the embodiments of this application. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, so that a process, method, system, product, or apparatus that comprises a series of elements is not necessarily limited to those elements, but may include other elements not explicitly listed or inherent to those processes, methods, products, or apparatuses.

[0104] In real-world scenarios, see Figure 1 , Figure 1 This application provides a schematic diagram of a power system structure, which includes a power converter and at least one photovoltaic string. The power converter is an electrical device that changes the voltage, frequency, number of phases, and other electrical quantities or characteristics of the power system. The power converter can be a type of converter such as a photovoltaic-storage converter. Based on different functions, power converters can be classified as rectifiers for converting AC to DC, inverters for converting DC to AC, or converters with bidirectional DC-AC conversion capabilities. Depending on the model, the power conversion circuit is connected to the corresponding applicable single-phase or three-phase power grid via a grid-side switch.

[0105] The power conversion circuit contains a power conversion circuit and a boost circuit. When the power converter is a rectifier, the power conversion circuit is a rectifier circuit; when the power converter is an inverter, the power conversion circuit is an inverter circuit; and when the power converter is a converter, the power conversion circuit is a converter circuit.

[0106] Boost circuit can be Figure 1 The system contains m Boost circuits, where m is a positive integer greater than or equal to 1. Each Boost circuit has an input port, which can also be called an MPPT (Maximum Power Point Tracking) port. Each MPPT port can be divided into multiple parallel PV (Photovoltaic) ports within the power converter, or it can be directly configured as a single PV port. Each PV port can connect to one photovoltaic string, or two parallel photovoltaic strings can be connected via a bus terminal. At least one photovoltaic string can be connected to a power system.

[0107] A photovoltaic string consists of multiple DC controllers. The specific structure of a photovoltaic string can be found in [reference needed]. Figure 2As shown, the power system can be a system in which each photovoltaic string is equipped with a DC controller. A photovoltaic string includes at least one photovoltaic module (e.g., photovoltaic module 1 to photovoltaic module n, where n is a positive integer), and each photovoltaic module includes a DC controller (e.g., ...). Figure 2 The DC controllers in the diagram are 1, 2, 3...n, where n is a positive integer. These DC controllers can be optimizers or shutdown devices. The optimizer can be a photovoltaic power optimizer, which is a module-level power electronic device (MLPE) with DC input and DC output.

[0108] The input terminal of the DC controller is used to connect to a DC source, which can be a photovoltaic unit. The photovoltaic unit includes at least one photovoltaic module, which is connected to the input side of the DC controller. The output terminals of each DC controller are connected in series to the input terminal of the power converter. In specific implementation, the negative output terminal of the previous DC controller is connected to the positive output terminal of this DC controller, the negative output terminal of this DC controller is connected to the positive output terminal of the next DC controller, and finally connected to a PV port of the power converter. Figure 2 In the diagram, the input + of DC controller 1 is connected to the output + of photovoltaic module 1. Figure 2 The input of DC controller 1 is connected to the output of photovoltaic module 1. The output of DC controller 1 is used as PV+. The output of DC controller 1 is connected to the output of DC controller 2. The remaining connections are described in the above description.

[0109] By connecting the DC controller and photovoltaic modules in series, the DC controller can use current and voltage prediction technology to ensure that the photovoltaic modules are always in the optimal working state. This can solve the problem of the impact of shading, inconsistent orientation, or differences in electrical specifications of photovoltaic power plants on power generation, realize the maximum power output of photovoltaic modules, and improve the power generation of the power system.

[0110] It should be noted that the number of photovoltaic modules in different photovoltaic strings connected to the same power system can be the same or different. Furthermore, the series-parallel connection method of photovoltaic strings connected to different MPPT ports can be the same or different. Additionally, the power output of the photovoltaic units can be the same or different.

[0111] In one implementation, a schematic diagram of a power system can be referenced. Figure 3 As shown, k photovoltaic (PV) strings are connected to m Boost circuits of a power converter. A Boost circuit may or may not be connected to any PV strings. Each Boost circuit may or may not have any PV strings connected to its MPPT port. Here, k and m are positive integers.

[0112] When the power converter is an inverter, the power conversion circuit includes, in addition to the inverter circuit and the boost circuit, such as Figure 4 As shown, it may also include an inverter control module and a communication module. The inverter control module acts as a control module, used to implement the control functions of various components in the inverter. The communication module can communicate with the DC controller and other inverters via a magnetic ring. Specifically, the communication module can be a PLC (Power Line Communication) master node. When the inverter and DC controller communicate via the PLC, the PLC master node in the inverter acts as the master node, and the DC controller acts as the slave node.

[0113] After the DC controller and power converter in the power system are installed, during the site search process (specifically, the inverter can automatically search for all DC controllers installed under the machine), the power converter can automatically search for all DC controllers connected to the power converter through the communication module. However, in actual scenarios, since it is impossible to guarantee good communication between the inverter and all DC controllers, the problem of not completely searching for all DC controllers often occurs, i.e., the problem of missing searches.

[0114] Furthermore, in a photovoltaic power plant, the AC and DC lines of multiple inverters converge together. One inverter (such as inverter A) sends a search signal, which is transmitted to the DC controller installed under another inverter (such as inverter B) via the AC or DC line. The DC controller under inverter B will reply to inverter A, causing inverter A to recognize the DC controller under inverter B as its own installed DC controller. That is, it identifies the DC controllers connected to other power converters that it has searched as its own connected DC controllers, resulting in more DC controllers being searched than actually searched, i.e., the over-search problem.

[0115] Whether it's the aforementioned few-search problem or many-search problem, both will result in lower accuracy of the DC controller connected to the power converter determined through the search operation, thus reducing the control accuracy of the power converter over the DC controller.

[0116] To address this, this application provides a power system and equipment search method. In this application, after a power converter broadcasts an information query request, the first DC controller receiving the broadcast request can forward the request within its DC string. This allows the second DC controller, which did not normally receive the broadcast request, to also receive it and respond to it. This enables the power converter to search for the second DC controller, avoiding the problem of not finding the DC controller due to the second DC controller not normally receiving the request. Furthermore, from the received feedback information, feedback information whose communication quality meets preset requirements is determined and used as target feedback information. The device identification information in the target feedback information is recorded. Only the DC controllers corresponding to the recorded device identification information are identified as DC controllers connected to the power converter. Communication quality limitations are used to filter out DC controllers not connected to the power converter, thus preventing the identification of other power converters' connected DC controllers as the power converter's own. This improves the accuracy of identifying the DC controllers connected to the power converter through the search operation, thereby improving the power converter's control accuracy over the DC controllers.

[0117] Based on the above, one embodiment of this application provides a power system including a power converter and at least one DC string; the DC string includes multiple DC controllers, the input terminals of which are connected to a DC source, and the output terminals of each DC controller are connected in series to the input terminal of the power converter. For a specific structure, please refer to [reference needed]. Figures 1 to 4 As shown.

[0118] In this embodiment, the following examples will be used to illustrate the concept of a power converter as an inverter and a power conversion circuit as an inverter circuit. The implementation process of other types of power converters is similar.

[0119] The interaction process between the power converter and the DC controller can be referred to Figure 5 Specifically, it includes the following steps:

[0120] S11, Power converter broadcast information query request.

[0121] The information query request is used to search for DC controllers that are connected to the power converter. The content of the information query request can be configured according to actual needs.

[0122] In practical scenarios, taking a power converter as an inverter as an example, the PLC master node in the inverter acts as the master node, and the DC controller acts as the slave node. The two communicate with each other through PLC communication.

[0123] The PLC master node in the inverter initiates an automatic search, broadcasting a discovery request (discovery_command) to all surrounding communicable devices. These communicable devices can be DC controllers connected to the power converter, or DC controllers connected to other power converters that are susceptible to crosstalk but capable of receiving the query request. In practical scenarios, this application does not specify which communicable devices will receive the query request during the broadcast operation by the PLC master node in the inverter.

[0124] S12. After receiving the information query request, the first DC controller responds to the information query request and sends feedback information carrying the device identification information of the first DC controller to the power converter.

[0125] The first DC controller is the DC controller that directly receives the information query request broadcast by the power converter. In actual scenarios, the first DC controller can be all or some of the DC controllers that are connected to the power converter, depending on the communication situation.

[0126] In practical scenarios, PLC communication mechanisms can employ CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance). CSMA / CA is an algorithm that avoids data transmission conflicts between stations during data transmission. Its characteristic is that it cannot detect channel collisions while sending packets; it can only try to "avoid" them. At any given time, only the master node is allowed to send a signal or one slave node can reply to the master node during PLC communication. After the master node sends an information query request, multiple DC controllers will receive the request, but they are not allowed to reply simultaneously. Instead, they compete through the CSMA / CA mechanism. The DC controller that wins the competition reports its progress. If the competition fails, after the successful DC controller reports its progress, the competition can resume until the competition time exceeds the maximum reporting timeout `maxseq_time`, at which point no reply is sent.

[0127] In this embodiment, the DC controllers compete using a CSMA / CA mechanism. If a DC controller wins the information reply permission through the CSMA / CA mechanism, it can reply to the power converter. In this embodiment, the DC controller reports feedback information carrying the device identification information of the first DC controller to the power converter. This device identification information can be an identification code (iden_code), which can be numbers, letters, or a combination of them. In one example, the identification code (iden_code) is the DC controller's SN (Serial Number), which is used to uniquely identify a DC controller. The device identification information can be reported in the form of an information response message (response_data).

[0128] S13. The first DC controller forwards the information query request within the DC string where the first DC controller is located.

[0129] Specifically, to address the issue of insufficient search due to the inability to guarantee good communication between the power converter and all DC controllers, in this embodiment, the first DC controller forwards the information query request after receiving it. This allows the second DC controller, whose communication quality with the power converter is not ideal, to indirectly receive the information query request through this forwarding operation. In practical scenarios, the first DC controller can forward the request via broadcast within its own DC string, and if communication quality permits, it can also forward it to DC controllers under other power converters.

[0130] S14. The second DC controller feeds back feedback information carrying the device identification information of the second DC controller to the power converter.

[0131] In this context, a second DC controller refers to a DC controller that does not directly receive information query requests broadcast by the power converter. The number of second DC controllers can be zero or at least one, meaning there may be no second DC controller. In one example, a power converter is connected to three DC controllers. These three DC controllers have good communication quality with the power converter and can normally receive requests from it. In this case, all three DC controllers are considered first DC controllers, and there are no second DC controllers. In another example, if two DC controllers have good communication quality with the power converter and can normally receive requests, and one DC controller has poor communication quality and cannot normally receive requests, then the two DC controllers with good communication quality with the power converter are considered first DC controllers, and the one with poor communication quality is considered the second DC controller.

[0132] In one implementation, after receiving the forwarded information query request, the second DC controller forwards the information query request within the DC string where the second DC controller is located. That is, the second DC controller can also forward the information query request so that the DC controller that has not received the forwarded information query request from the first DC controller can receive the information query request normally.

[0133] For example, a power converter is connected to four DC controllers: DC controller 1, DC controller 2, DC controller 3, and DC controller 4. After the power converter broadcasts a query request, DC controller 1 receives the request normally, becoming the first DC controller. DC controller 1 then forwards the query request. DC controllers 2 and 3 receive the forwarded query request, becoming the second DC controllers. Subsequently, DC controllers 2 and 3 also forward the query request. DC controller 4 receives the query request forwarded by DC controller 2, and can also become a second DC controller. It can then compete using a CSMA / CA mechanism to reply with feedback information carrying its device identification information to the power converter. Afterward, DC controller 4 can also forward the query request. That is, after each DC controller receives the query request, it performs a forwarding operation to ensure that each DC controller receives the query request, even when the power converter is connected to a large number of DC controllers.

[0134] In a real-world scenario, the second DC controller may receive at least one information query request forwarded by the first DC controller, and / or at least one information query request forwarded by the second DC controller. In this case, to avoid duplicate responses to the requests, only the first information query request forwarded by the first DC controller and the first information query request forwarded by the other second DC controllers will be responded to. For other information query requests received after the first information query request, an invalid bit can be marked to avoid responding again.

[0135] After responding to the first information query request, the second DC controller can directly feed back feedback information carrying its device identification information to the power converter via its communication link with the power converter through a CSMA / CA competition mechanism. Alternatively, in another implementation, the second DC controller can also upload the feedback information to the power converter via forwarding. Specifically, the second DC controller determines the first DC controller to which to forward the information query request, and feeds back the feedback information carrying its device identification information to the first DC controller, so that the first DC controller forwards the feedback information carrying the second DC controller's device identification information to the power converter. This first DC controller can be the first DC controller or another second DC controller.

[0136] It should be noted that since the power converter sends a request to the DC controller via a downlink communication link, there may be situations where the DC controller cannot receive the request sent by the power converter. However, the DC controller reports information to the power converter via an uplink communication link. Under normal circumstances, the power converter can receive the information reported by the DC controller. Therefore, although the second DC controller did not receive the information query request directly broadcast by the power converter, it can directly report feedback information to the power converter.

[0137] For example, a power converter is connected to four DC controllers: DC controller 1, DC controller 2, DC controller 3, and DC controller 4. After the power converter broadcasts an information query request, DC controller 1 normally receives the request. At this point, DC controller 1 is the first DC controller. Then, DC controller 1 forwards the information query request. DC controller 2 and DC controller 3 also receive the forwarded information query requests. DC controller 2 will forward the request again, and DC controller 3 will receive the request forwarded by DC controller 2. At this point, DC controller 3 has received the information query requests forwarded by DC controller 1 and DC controller 2 in sequence. Since it received the request forwarded by DC controller 1 first, it will only respond to the request forwarded by DC controller 1, directly sending feedback information carrying the device identification information of DC controller 3 to the power converter, or transmitting the feedback information to DC controller 1 first, and then DC controller 1 forwarding the feedback information to the power converter.

[0138] S15. The power converter receives feedback information from each DC controller; from the received feedback information, it determines the feedback information whose communication quality meets the preset requirements and uses it as the target feedback information; it records the device identification information in the target feedback information to determine that the DC controller corresponding to the recorded device identification information is: the DC controller that has a connection relationship with the power converter.

[0139] In practical scenarios, after the DC controller responds to the query request and sends feedback information to the power converter, the power converter can receive feedback information from at least one DC controller. In subsequent implementations, to avoid crosstalk, the DC controllers connected to other power converters are identified as the DC controllers connected to the power converter itself. This leads to searching for more DC controllers than actually connected, a problem known as the "multiple search problem." Analysis reveals that DC controllers with actual connections to the power converter are not affected by crosstalk, resulting in higher communication link quality. Conversely, DC controllers without actual connections to the power converter are affected by crosstalk, leading to lower communication link quality. Therefore, although crosstalk may cause a power converter to receive responses from DC controllers connected to other power converters, the communication signal quality of these other controllers is lower than that of the DC controllers connected to the power converter. Thus, the problem of multiple search problems can be solved by filtering out non-connected DC controllers based on communication quality.

[0140] In order to filter out DC controllers that are not connected to itself by means of communication quality, the embodiments of this application will set preset requirements. The preset requirements may be the corresponding thresholds for communication signal quality data, and the thresholds can be configured according to the actual scenario.

[0141] If the communication quality between the DC controller and the power converter meets the preset requirements, such as the communication signal quality data being greater than the corresponding threshold, it indicates that the DC controller is the DC controller connected to the power converter. At this time, the feedback information that the communication quality meets the preset requirements is determined as the target feedback information. The device identification information in the target feedback information is recorded to determine that the DC controller corresponding to the recorded device identification information is the DC controller that has a connection relationship with the power converter.

[0142] If the communication quality between the DC controller and the power converter does not meet the preset requirements, such as the communication signal quality data not being greater than the corresponding threshold, it indicates that the DC controller is connected to another power converter. Due to crosstalk, it reports its own device identification information to this power converter. In this case, filtering the DC controller will allow you to find the DC controller directly connected to the power converter.

[0143] In this embodiment, after the converter broadcasts an information query request, the DC controller that receives the broadcast request can forward it within its DC string. This allows DC controllers that did not normally receive the request to also receive it and respond, enabling the power converter to find the DC controller and avoiding the problem of not finding the DC controller due to the DC controller not normally receiving the request. Furthermore, from the received feedback information, feedback information whose communication quality meets preset requirements is identified as target feedback information. The device identification information in the target feedback information is recorded. Only the DC controllers corresponding to the recorded device identification information are identified as DC controllers connected to the power converter. Communication quality limitations are used to filter out DC controllers not connected to this power converter, thus preventing the identification of DC controllers connected to other power converters as the power converter's own DC controller. This improves the accuracy of identifying the DC controllers connected to the power converter through the search operation, thereby improving the control accuracy of the power converter over the DC controllers.

[0144] Based on any of the above embodiments, the information query request carries corresponding data. In one implementation, refer to... Figure 6 When a power converter is used to request broadcast information, the specific steps include the following:

[0145] S21. Determine the specified query sequence number and obtain the maximum timeout period.

[0146] In one implementation, since a single search operation requires multiple interactions between the power converter and the DC controller, to ensure the DC controller can determine that each interaction belongs to a single search, this embodiment includes a specified query number seq_num in the information query request. The specified query number seq_num refers to the sequence number of the current search operation; different search operations may have the same or different sequence numbers, depending on the actual configuration. This specified query number seq_num remains unchanged until the current automatic search ends.

[0147] Regarding the specified query number, it can be randomly generated by the power converter. Before initiating the automatic search, the inverter control module in the power converter first randomly generates the specified query number seq_num. Alternatively, the specified query number seq_num can be generated according to certain rules, such as incrementing the specified query number seq_num from the previous search operation to obtain the specified query number for the current search. In one implementation, the specified query number can be at least one number, at least one letter, or a combination of numbers and letters.

[0148] In one implementation, to ensure timely communication, the maximum response time of the DC controller can be limited. The maximum response time refers to the maximum timeout time maxseq_time reported by the node. maxseq_time is an empirical value that can be agreed upon in advance. After receiving the information query request, the DC controller should reply to the power converter within maxseq_time. If the timeout occurs, no reply will be given.

[0149] S22. Construct an information query request that includes the specified query sequence number and the maximum timeout period.

[0150] Specifically, the information query request `discovery_command` carries the specified query sequence number `seq_num` and the maximum timeout, i.e., the maximum timeout for reporting from the node, `maxseq_time`. The request construction process can be based on the PLC communication mechanism.

[0151] S23. Activate the automatic search function and broadcast information query requests to communicable devices around the power converter.

[0152] The PLC master node in the power converter starts automatic search and broadcasts information query requests to all surrounding communicable devices. The DC controller that receives the information query request will forward the information query request.

[0153] In one implementation, when the power converter broadcasts an information query request to a communicable device around the power converter, it can use its own communication module to send the information query request to a magnetic ring connected to the communication module, so that the magnetic ring broadcasts the information query request to the communication link where the communicable device around the power converter is located.

[0154] like Figure 4 As shown, a magnetic ring is installed on the communication link between the Boost circuit and the photovoltaic string. The power converter uses its own PLC master node to send information query requests to the magnetic ring. Then, the magnetic ring can broadcast the information query requests to the communication links of the communication devices around the power converter, thus realizing the broadcast operation of the request.

[0155] After the power converter broadcasts the information query request, when the first DC controller sends feedback information carrying the device identification information of the first DC controller to the power converter, if it determines that it has received an information query request including the specified query number and has reported its own device identification information, it marks the specified query number to avoid reporting its own device identification information again.

[0156] Specifically, in addition to identifying the current search operation, the specified query number seq_num is also used to instruct the DC controller that has received a query request containing the specified query number and has reported its own device identification information to mark the specified query number when it receives another query request containing the specified query number, so as to avoid responding to the query request containing the specified query number again.

[0157] To elaborate, since only one DC controller is allowed to respond to the request at any given time, in order to avoid the same DC controller successfully competing multiple times and thus responding to the power converter multiple times, in this embodiment of the application, multiple information query requests are issued during a search process. When a DC controller that has received an information query request including a specified query number and has reported its own device identification information receives another information query request including a specified query number, it marks the specified query number and will not respond to information query requests including the specified query number again, so that the DC controller that did not succeed in competing has the opportunity to report its own information.

[0158] If the DC controller determines that it has not received an information query request including the specified query number, or has received an information query request including the specified query number but has not reported its own device identification information, and if it wins the information reply permission, it will report its own device identification information to the power converter within the maximum timeout period.

[0159] In practice, if the DC controller determines that it has not received an information query request including the specified query number, or has received an information query request including the specified query number but has not reported its own device identification information, it can compete for the information reply permission through the CSMA / CA mechanism. If it wins the information reply permission, it will report its own device identification information to the power converter within the maximum timeout period.

[0160] If a DC controller detects that it has reached the maximum timeout period and has failed to report its own device identification information because it has not successfully competed for the information reply permission, it will stop reporting and wait for the next information query request before reporting again. If it wins the information reply permission within the maximum timeout period, the DC controller must report its own device identification information within the maximum timeout period.

[0161] In this embodiment, according to the CSMA / CA mechanism, only at least one DC controller can be found in a single interaction. For example, within the maximum timeout period, DC controller 1 first competes for the information reply permission and reports feedback information. After successful reporting, DC controller 2 competes for the information reply permission and reports feedback information. After successful reporting, DC controller 3 competes for the information reply permission and reports feedback information. After successful reporting, the maximum timeout period is reached. At this time, the power converter receives the feedback information reported by DC controllers 1, 2, and 3, that is, three DC controllers have been found. Subsequently, the DC controllers with which the power converter has a connection relationship are determined based on the communication quality.

[0162] Based on any of the above-described device search methods, in one implementation, the power converter is further used for:

[0163] Determine the device identification information list conf_list.

[0164] The device identification information list includes: device identification information of DC controllers that have been found to be connected to the power converter.

[0165] The initial content of the device identification information is empty, and the device identification information list can be continuously updated based on the search results of the power converter. In specific implementation, as the power converter continuously searches for DC controllers, it gradually finds a DC controller. If the communication quality between the DC controller and the power converter meets preset requirements, the power converter considers the DC controller to be a DC controller with a connection relationship with the power converter. At this point, in one implementation, the device identification information of the DC controller can be added to the device identification information list. That is, the DC controller in the device identification information list has received an information query request including a specified query number and has reported its own device identification information.

[0166] In real-world scenarios, as the number of interactions during the search increases, more DC controllers can be identified, and the device identification information list can be continuously updated based on the search results for power converters.

[0167] After determining the list of device identification information, when constructing an information query request that includes a specified query number and a maximum timeout, it can be as follows:

[0168] Construct an information query request that includes a specified query sequence number, a maximum timeout period, and a list of device identification information.

[0169] In one implementation, the first DC controller is used to determine that it has received an information query request including a specified query number and has reported its own device identification information. If it determines that its own device identification information is included in the device identification information list, it then determines that it has received an information query request including a specified query number and has reported its own device identification information.

[0170] Specifically, after receiving an information query request, the DC controller matches its own device identification information with the device identification information in the device identification information list. If its own device identification information is found in the list, it means that it has already received an information query request including the specified query number and reported its own device identification information. It does not need to report the device identification information again, and can mark the specified query number as reported. If it receives another information query request with the same number, it will not respond. If its own device identification information is not found in the list, it means that it has not reported its device identification information. It can then compete for information response rights through the CSMA / CA mechanism. If it wins the competition, it can report its own device identification information. If the communication quality between the DC controller and the power converter meets preset requirements, the DC controller is considered to be connected to the power converter, and the device identification information of the DC controller connected to the power converter found in this search is added to the device identification information list.

[0171] After the maximum timeout period is reached in this interaction operation, the power converter can reconstruct the information query request, which includes the specified query number, the maximum timeout period, and the latest device identification information list, and broadcast the information query request again. The above steps are repeated until there are no DC controllers reporting their own device identification information or the maximum search time is reached.

[0172] In this embodiment, by configuring a device identification information list and including the device identification information list in each information query request, the DC controller can promptly know whether it has reported device identification information. If it has already reported device identification information, it will not report it again, thus avoiding duplicate reporting of device identification information.

[0173] Based on any of the above embodiments, the feedback information also includes the signal strength of the communication link between the DC controller and the power converter.

[0174] In a real-world scenario, upon receiving an information query request broadcast by the power converter, the DC controller can acquire communication data from the communication link at the time the query request was received. This communication data can include signal power, amplitude, noise, etc. Based on this communication data, the signal strength and / or signal-to-noise ratio of the communication link between the DC controller and the power converter are then calculated.

[0175] Among them, the signal strength (RSSI, Received Signal Strength Indicator) refers to the strength or power level of the PLC signal transmitted on the power line. The higher the signal strength, the more reliable and wider the coverage of the PLC communication.

[0176] Signal-to-noise ratio (SNR) refers to the ratio of signal to noise in PLC communication. The higher the SNR, the easier and more accurate the receiver can decode the received signal.

[0177] After the DC controller calculates the signal strength and / or signal-to-noise ratio, the target DC controller can report only the signal strength to the power converter. In specific reporting, it can be reported together with the device identification information in the form of an information response message (response_data).

[0178] After receiving the signal strength reported by the target DC controller, the power converter can use feedback information, including signal strengths greater than the signal strength threshold, as target feedback information.

[0179] Specifically, if the signal strength between the DC controller and the power converter is greater than the signal strength threshold, it indicates that the communication quality between the two is relatively good. It also indicates that the DC controller is able to communicate with the power converter not due to crosstalk. The DC controller is the DC controller connected to the power converter. At this time, the feedback information reported by the DC controller can be used as the target feedback information, and the DC controller can be identified as the DC controller connected to the power converter.

[0180] The above embodiment only reports signal strength. In another implementation, the target DC controller can also report signal strength and signal-to-noise ratio (SNR) simultaneously. Specifically, this can be reported along with device identification information in the form of a response_data message. In this case, the feedback information also includes the signal strength and SNR of the communication link between the DC controller and the power converter. The power converter can receive the signal strength and SNR reported by the DC controller and calculate the link quality using these parameters. The link quality is determined by the signal strength and SNR. The power converter can calculate the link quality between the target DC controller and the power converter based on the correspondence between RSSI, SNR, and link quality. This correspondence can be based on the Shannon-Hartley theorem, etc., and can be configured according to actual needs. A higher link quality value indicates better communication quality.

[0181] After the power converter calculates the link quality, it determines the feedback information corresponding to link quality values ​​greater than a link quality threshold and uses this as the target feedback information. Specifically, if the link quality between the DC controller and the power converter is greater than the link quality threshold, it indicates that the communication quality between the two is relatively good, and it also indicates that the DC controller is not communicating with the power converter due to crosstalk. This DC controller is the DC controller connected to the power converter. In this case, the feedback information reported by the DC controller is used as the target feedback information, and subsequently, this DC controller is determined to be the DC controller connected to the power converter.

[0182] The above embodiment calculates the link quality using the power converter. In another implementation, the DC controller can calculate the link quality using signal strength and signal-to-noise ratio, and report the link quality to the power converter. In this case, the feedback information also includes the link quality of the communication link between the DC controller and the power converter. The power converter receives the link quality reported by the DC controller, determines the feedback information corresponding to link quality values ​​greater than a link quality threshold, and uses this as the target feedback information. Subsequently, the DC controller corresponding to this target feedback information is identified as the DC controller connected to the power converter.

[0183] It should be noted that the process of calculating link quality by the DC controller is the same as that by the power converter, only the device used to calculate the link quality is different. If the power converter has a large processing load, the link quality calculation can be performed by the DC controller. If the power converter has a small processing load, the link quality calculation can be performed by either the DC controller or the power converter, depending on the actual configuration.

[0184] In this embodiment, the power converter filters out non-local sites based on one of the signal strength, signal strength and signal-to-noise ratio, and link quality carried in the information response message reported by the DC controller, in order to solve the multi-search problem.

[0185] Specifically, in order to enable those skilled in the art to better understand this application, the following is combined with... Figure 7 The following example illustrates a specific implementation of this application. In this example, the power converter is the master node, and the DC controller is the slave node (or site). The master node obtains its connected slave nodes through a search operation.

[0186] 1) The master node randomly generates a specified query sequence number seq_num, which remains unchanged until the end of this automatic search.

[0187] 2) The master node starts automatic search and broadcasts a query request, discovery_command, to all surrounding slave nodes. The discovery_command carries seq_num, the maximum timeout time reported by the slave node, maxseq_time, and a list of device identification information of the slave nodes found in the previous round, conf_list. When the master node broadcasts the query request for the first time, the content of conf_list is empty.

[0188] 3) Since the initial `conf_list` is empty, the slave node starts timing upon receiving the `discovery_command` and simultaneously initiates the CSMA / CA mechanism. It either forwards the `discovery_command` first, then reports the response message `response_data`, or reports the response message `response_data` first, then forwards the `discovery_command`. The `response_data` carries a generated identifier `iden_code` to identify itself as a slave node, and also includes communication signal quality data (signal strength, signal strength and signal-to-noise ratio, or link quality). If the timing reaches `maxseq_time` and the slave node fails to report due to unsuccessful contention, it stops reporting and waits for the next `discovery_command` before resuming reporting.

[0189] 4) After receiving the response_data reported by the nearby slave node, the master node compares the communication signal quality data of the response_data with the threshold. If it is greater than or equal to the threshold, the master node records the idea_code of the reporting slave node in the conf_list. The conf_list is used to mark which slave nodes have replied with information response messages response_data.

[0190] 5) The master node keeps seq_num unchanged, reassembles the packet information query request, and continues to broadcast the information query request discovery_command to all surrounding slave nodes, while carrying code_list. conf_list includes a list composed of the idea_code of all slave nodes that have successfully reported in the previous rounds.

[0191] 7) When a nearby node receives a discovery_command, it first forwards the discovery_command, then matches the idea_code in the code_list. If it does not find its own idea_code, it will re-report response_data. If it finds that its own random_code already exists, it will not report response_data again, and at the same time mark that the current seq_num has been reported. If it receives a request message with the same sequence number again in the future, it will not respond.

[0192] 8) After receiving the response_data reported by the nearby node, the master node compares the communication signal quality data of the response_data with the threshold. If it is greater than or equal to the threshold, the master node records the idea_code of the reported slave node in the conf_list.

[0193] 9) Repeat steps 5-8 above until no nearby nodes report (or the number of times no nodes report exceeds the specified number) or the search time exceeds the timeout period (where the timeout period refers to the maximum search time for the master node to search for the slave node; if this time is exceeded, the master node will no longer send query signals, and the search ends).

[0194] In this embodiment, the master node broadcasts an information query request. Upon receiving the request, the slave node initiates the process, first forwarding the query request and then reporting an information response message, or vice versa, to address the issue of insufficient searches. Additionally, the master node filters out sites not belonging to its own machine based on the link quality information carried in the information response message, thus addressing the issue of excessive searches.

[0195] Based on the above, one embodiment of this application provides a device search method that uses a power converter in a power system. The power system also includes at least one DC string, which includes multiple DC controllers. The input terminals of the DC controllers are used to connect to a DC source, and the output terminals of each DC controller are connected in series to the input terminal of the power converter.

[0196] Reference Figure 8 Device search methods include:

[0197] S31. Broadcasting an information query request, so that after receiving the information query request broadcast by the power converter, the first DC controller responds to the information query request and sends back feedback information carrying the device identification information of the first DC controller to the power converter; and forwarding the information query request within the DC string where the first DC controller is located, so that the second DC controller, which has not received the information query request broadcast by the power converter, sends back feedback information carrying the device identification information of the second DC controller to the power converter based on the forwarded information query request.

[0198] S32, Receive feedback information from each DC controller;

[0199] S33. From the feedback information received from each station, determine the feedback information whose communication quality meets the preset requirements, and use it as the target feedback information;

[0200] S34. Record the device identification information in the target feedback information to determine that the DC controller corresponding to the recorded device identification information is a DC controller that is connected to the power converter.

[0201] In one implementation, the broadcast information query request includes:

[0202] Determine the specified query sequence number and obtain the maximum timeout period;

[0203] Construct an information query request that includes a specified query sequence number and a maximum timeout period;

[0204] The automatic search function is activated, broadcasting information query requests to communicable devices around the power converter. If the DC converter determines that it has received an information query request with a specified query number and has reported its own device identification information, it will mark the specified query number to avoid reporting its own device identification information again. If it determines that it has not received an information query request with a specified query number, or has received an information query request with a specified query number but has not reported its own device identification information, and if it wins the information reply permission, it will report its own device identification information to the power converter within the maximum timeout period.

[0205] In one implementation, broadcasting an information query request to communicable devices around the power converter includes:

[0206] The information query request is sent to the magnetic ring connected to the communication module using its own communication module, so that the magnetic ring broadcasts the information query request to the communication link where the communicable devices around the power converter are located.

[0207] In one implementation, the device search method further includes:

[0208] The device identification information list is determined; the device identification information list includes: device identification information of DC controllers that are connected to the power converter and have been found by the power converter; the device identification information list can be continuously updated according to the search results of the power converter, and the initial content of the device identification information is empty;

[0209] Construct an information query request that includes a specified query sequence number and a maximum timeout period, including:

[0210] A query request is constructed that includes a specified query number, a maximum timeout period, and a list of device identification information. This allows the DC controller to determine, if it finds that its own device identification information is included in the list, that it has received a query request with the specified query number and has reported its own device identification information.

[0211] In one implementation, after determining that the DC controller corresponding to the recorded device identification information is a DC controller connected to the power converter, the device search method further includes:

[0212] Add the device identification information of the DC controllers that are connected to the power converter found in this search to the device identification information list;

[0213] Reconstruct the information query request, including the specified query sequence number, maximum timeout, and the latest device identification information list, broadcast the information query request again, and execute them sequentially.

[0214] In one implementation, the feedback information also includes the signal strength of the communication link between the DC controller and the power converter;

[0215] From the received feedback information, identify the feedback information that meets the preset requirements for communication quality and use it as the target feedback information, including:

[0216] Feedback information with signal strength greater than the signal strength threshold is used as target feedback information.

[0217] Alternatively, the feedback information may also include the signal strength and signal-to-noise ratio of the communication link between the DC controller and the power converter;

[0218] From the received feedback information, identify the feedback information that meets the preset requirements for communication quality and use it as the target feedback information, including:

[0219] The link quality is calculated using signal strength and signal-to-noise ratio.

[0220] Determine the feedback information corresponding to link quality exceeding the link quality threshold, and use it as the target feedback information;

[0221] Alternatively, the feedback information may also include the link quality of the communication link between the DC controller and the power converter;

[0222] From the received feedback information, identify the feedback information that meets the preset requirements for communication quality and use it as the target feedback information, including:

[0223] Determine the feedback information corresponding to link quality values ​​greater than the link quality threshold, and use this as the target feedback information.

[0224] In this embodiment, after the power converter broadcasts an information query request, the first DC controller that receives the broadcast request can forward it within its DC string. This allows the second DC controller, which may not have received the broadcast request, to also receive it and respond to it. This enables the power converter to locate the second DC controller, avoiding the problem of not finding the controller due to the second controller not receiving the request. Furthermore, from the received feedback information, feedback information whose communication quality meets preset requirements is identified as target feedback information. The device identification information in the target feedback information is recorded. Only the DC controllers corresponding to the recorded device identification information are identified as having a connection to the power converter. Communication quality limitations filter out DC controllers not connected to the power converter, thus preventing the identification of other power converters' connected DC controllers as the power converter's own. This improves the accuracy of identifying the DC controllers connected to the power converter through the search operation, thereby improving the power converter's control accuracy over the DC controllers.

[0225] It should be noted that the specific implementation of each step in this embodiment is described in the corresponding descriptions above.

[0226] Based on the above, one embodiment of this application provides a device search method, which applies any one of a plurality of DC controllers in at least one DC string in a power system. The power system also includes a power converter. The input terminal of the DC controller is used to connect to a DC source, and the output terminal of each DC controller is connected in series to the input terminal of the power converter.

[0227] Reference Figure 9 Device search methods include:

[0228] S41. Receive the information query request broadcast by the power converter;

[0229] S42. In the case of a first DC controller receiving an information query request broadcast by a power converter, after receiving the information query request, responding to the information query request, sending back feedback information carrying the device identification information of the first DC controller to the power converter, and forwarding the information query request within the DC string where the first DC controller is located.

[0230] S43. In the case where the second DC controller has not received the information query request broadcast by the power converter, based on the forwarded information query request, feedback information carrying the device identification information of the second DC controller is sent back to the power converter, so that the power converter can receive the feedback information from each DC controller; from each received feedback information, the feedback information whose communication quality meets the preset requirements is determined and used as the target feedback information; the device identification information in the target feedback information is recorded to determine that the DC controller corresponding to the recorded device identification information is: the DC controller that has a connection relationship with the power converter.

[0231] In one implementation, when the information query request includes a specified query number and a maximum timeout period, feedback information carrying device identification information of the first DC controller is sent to the power converter, including:

[0232] If it is determined that a query request containing the specified query number has been received and the device identification information of the device has been reported, the specified query number is marked to avoid reporting the device identification information of the device again.

[0233] If it determines that it has not received an information query request including the specified query number, or has received an information query request including the specified query number but has not reported its own device identification information, and if it wins the information reply permission, it shall report its own device identification information to the power converter within the maximum timeout period.

[0234] In one implementation, when the information query request includes a specified query number, a maximum timeout period, and a list of device identification information, determining the device identification information that has received an information query request including the specified query number and has been reported includes:

[0235] If the device identification information is found to be included in the device identification information list, it is determined that the device identification information has been received with a query request including the specified query number and has been reported.

[0236] In one implementation, in the case of a second DC controller that has not received an information query request broadcast by the power converter, the device search method further includes:

[0237] After receiving the forwarded information query request, the information query request is forwarded within the DC string where the second DC controller is located.

[0238] Based on the forwarded information query request, feedback information carrying the device identification information of the second DC controller is sent back to the power converter, including:

[0239] In response to the first information query request forwarded by the first DC controller and the first information query request forwarded by the other second DC controllers, the first DC controller directly feeds back feedback information carrying the device identification information of the second DC controller to the power converter; or, the first DC controller determines that the information query request is forwarded to the second DC controller, and feeds back the feedback information carrying the device identification information of the second DC controller to the first DC controller, so that the first DC controller forwards the feedback information carrying the device identification information of the second DC controller to the power converter.

[0240] In one implementation, feedback information carrying device identification information of a first DC controller is fed back to the power converter, including:

[0241] Feedback information carrying the device identification information of the first DC controller and the signal strength of the communication link between the first DC controller and the power converter is sent to the power converter, so that the power converter takes the feedback information with a signal strength greater than the signal strength threshold as the target feedback information.

[0242] Alternatively, the device identification information of the first DC controller, the signal strength and signal-to-noise ratio of the communication link between the first DC controller and the power converter are fed back to the power converter, so that the power converter can use the signal strength and signal-to-noise ratio to calculate the link quality, determine the feedback information corresponding to the link quality that is greater than the link quality threshold, and use it as the target feedback information.

[0243] Alternatively, feedback information carrying the device identification information of the first DC controller and the link quality of the communication link between the first DC controller and the power converter is sent to the power converter, so that the power converter can determine the feedback information corresponding to the link quality greater than the link quality threshold and use it as the target feedback information.

[0244] In this embodiment, after the power converter broadcasts an information query request, the first DC controller that receives the broadcast request can forward it within its DC string. This allows the second DC controller, which may not have received the broadcast request, to also receive it and respond to it. This enables the power converter to locate the second DC controller, avoiding the problem of not finding the controller due to the second controller not receiving the request. Furthermore, from the received feedback information, feedback information whose communication quality meets preset requirements is identified as target feedback information. The device identification information in the target feedback information is recorded. Only the DC controllers corresponding to the recorded device identification information are identified as having a connection to the power converter. Communication quality limitations filter out DC controllers not connected to the power converter, thus preventing the identification of other power converters' connected DC controllers as the power converter's own. This improves the accuracy of identifying the DC controllers connected to the power converter through the search operation, thereby improving the power converter's control accuracy over the DC controllers.

[0245] It should be noted that the specific implementation of each step in this embodiment is described in the corresponding descriptions above.

[0246] This application also provides a computer program product including computer-readable instructions, which, when executed on an electronic device, cause the electronic device to implement any of the device search methods provided in this application.

[0247] This application also provides a computer-readable storage medium that carries one or more computer programs. When the one or more computer programs are executed by an electronic device, the electronic device can implement any of the device search methods provided in this application.

[0248] It should also be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. In addition, in the accompanying drawings of the device embodiments provided in this application, the connection relationship between modules indicates that they have a communication connection, which can be implemented as one or more communication buses or signal lines.

[0249] Through the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware, or it can be implemented by special-purpose hardware including application-specific integrated circuits, special-purpose CPUs, special-purpose memory, special-purpose components, etc. Generally, any function performed by a computer program can be easily implemented by corresponding hardware, and the specific hardware structure used to implement the same function can also be diverse, such as analog circuits, digital circuits, or special-purpose circuits. However, for this application, software program implementation is more often the preferred implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a readable storage medium, such as a computer floppy disk, USB flash drive, mobile hard disk, ROM, RAM, magnetic disk, or optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, training equipment, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0250] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product.

[0251] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, training device, or data center to another website, computer, training device, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a training device or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives (SSDs)).

Claims

1. A power system, characterized in that, include: Power converter and at least a DC string; The DC string includes multiple DC controllers, the input terminals of which are connected to a DC source, and the output terminals of each DC controller are connected in series to the input terminal of the power converter. The power converter is used to broadcast information query requests; A first DC controller that receives an information query request broadcast by the power converter is configured to respond to the information query request after receiving it, and send feedback information carrying the device identification information of the first DC controller to the power converter, and forward the information query request within the DC string where the first DC controller is located, so that a second DC controller that has not received the information query request broadcast by the power converter can send feedback information carrying the device identification information of the second DC controller to the power converter based on the forwarded information query request; The power converter is also used to receive feedback information from each of the DC controllers; determine feedback information whose communication quality meets preset requirements from the received feedback information, and use it as target feedback information; record the device identification information in the target feedback information, so as to determine that the DC controller corresponding to the recorded device identification information is a DC controller that has a connection relationship with the power converter.

2. The power system according to claim 1, characterized in that, The power converter is used for broadcast information query requests, specifically for: Determine the specified query sequence number and obtain the maximum timeout period; Construct an information query request that includes the specified query sequence number and the maximum timeout period; Activate the automatic search function and broadcast information query requests to communicable devices around the power converter; When the first DC controller sends feedback information carrying the device identification information of the first DC controller to the power converter, it is specifically used for: If it is determined that an information query request including the specified query number has been received and the device identification information of the device itself has been reported, the specified query number is marked to avoid reporting the device identification information of the device itself again. If it determines that it has not received an information query request including the specified query number, or has received an information query request including the specified query number but has not reported its own device identification information, and if it wins the information reply permission, it will report its own device identification information to the power converter within the maximum timeout period.

3. The power system according to claim 2, characterized in that, When the power converter broadcasts an information query request to communicable devices around it, it is specifically used for: The information query request is sent to the magnetic ring connected to the communication module using its own communication module, so that the magnetic ring broadcasts the information query request to the communication link of the communicable devices around the power converter.

4. The power system according to claim 2, characterized in that, The power converter is also used for: A device identification information list is determined; the device identification information list includes: device identification information of DC controllers that have been found to be connected to the power converter; the device identification information list can be continuously updated according to the search results of the power converter, and the initial content of the device identification information is empty; When the power converter is used to construct an information query request including the specified query number and the maximum timeout time, it is specifically used for: Construct an information query request that includes the specified query number, the maximum timeout time, and the device identification information list; The first DC controller is used to determine that when it has received an information query request including the specified query number and has reported its own device identification information, it is specifically used to: If the device identification information is found to be included in the device identification information list, it is determined that the device identification information has been received and reported by the device itself, including the specified query number.

5. The power system according to claim 1, characterized in that, The second DC controller is also used for: After receiving the forwarded information query request, the information query request is forwarded within the DC string where the second DC controller is located; When the second DC controller sends feedback information carrying the device identification information of the second DC controller to the power converter based on the forwarded information query request, it is specifically used for: In response to the first information query request forwarded by the first DC controller and the first information query request forwarded by other second DC controllers, the system directly feeds back feedback information carrying the device identification information of the second DC controller to the power converter; or, it determines the first DC controller that forwards the information query request to the second DC controller and feeds back the feedback information carrying the device identification information of the second DC controller to the first DC controller, so that the first DC controller forwards the feedback information carrying the device identification information of the second DC controller to the power converter.

6. The power system according to claim 4, characterized in that, The power converter is used to determine that the DC controller corresponding to the recorded device identification information is a DC controller connected to the power converter, and is further used to: Add the device identification information of the DC controllers that are connected to the power converter found in this search to the device identification information list; Reconstruct the information query request, including the specified query number, the maximum timeout, and the latest device identification information list, and broadcast the information query request again.

7. The power system according to claim 1, characterized in that, The feedback information also includes the signal strength of the communication link between the DC controller and the power converter; The power converter is used to determine, from the received feedback information, the feedback information in which the communication quality meets the preset requirements, and as the target feedback information, specifically for: Feedback information with signal strength greater than the signal strength threshold is used as target feedback information. Alternatively, the feedback information may also include the signal strength and signal-to-noise ratio of the communication link between the DC controller and the power converter; The power converter is used to determine, from the received feedback information, the feedback information in which the communication quality meets the preset requirements, and as the target feedback information, specifically for: The link quality is calculated using the signal strength and the signal-to-noise ratio. Determine the feedback information corresponding to link quality exceeding the link quality threshold, and use it as the target feedback information; Alternatively, the feedback information may also include the link quality of the communication link between the DC controller and the power converter; The power converter is used to determine, from the received feedback information, the feedback information in which the communication quality meets the preset requirements, and as the target feedback information, specifically for: Determine the feedback information corresponding to link quality values ​​greater than the link quality threshold, and use this as the target feedback information.

8. A device search method, characterized in that, The application of a power converter in a power system further includes at least one DC string, the DC string including multiple DC controllers, the input terminal of the DC controller being connected to a DC source, and the output terminal of each DC controller being connected in series to the input terminal of the power converter; The device search method includes: The system broadcasts an information query request so that, upon receiving the information query request broadcast by the power converter, the first DC controller responds to the information query request by sending feedback information carrying the device identification information of the first DC controller to the power converter, and forwards the information query request within the DC string where the first DC controller is located, so that the second DC controller, which has not received the information query request broadcast by the power converter, sends feedback information carrying the device identification information of the second DC controller to the power converter based on the forwarded information query request; Receive feedback information from each of the DC controllers; From the feedback information received from each station, the feedback information whose communication quality meets the preset requirements is determined as the target feedback information; Record the device identification information in the target feedback information to determine that the DC controller corresponding to the recorded device identification information is a DC controller that is connected to the power converter.

9. The device search method according to claim 8, characterized in that, The broadcast information query request includes: Determine the specified query sequence number and obtain the maximum timeout period; Construct an information query request that includes the specified query sequence number and the maximum timeout period; The automatic search function is activated, broadcasting information query requests to communicable devices around the power converter. If the DC converter determines that it has received an information query request including the specified query number and has already reported its own device identification information, it marks the specified query number to avoid reporting its own device identification information again. If it determines that it has not received an information query request including the specified query number, or has received an information query request including the specified query number but has not reported its own device identification information, and if it wins the information reply permission, it reports its own device identification information to the power converter within the maximum timeout period.

10. The device search method according to claim 9, characterized in that, The broadcast information query request to communicable devices around the power converter includes: The information query request is sent to the magnetic ring connected to the communication module using its own communication module, so that the magnetic ring broadcasts the information query request to the communication link of the communicable devices around the power converter.

11. The device search method according to claim 9, characterized in that, The device search method also includes: A device identification information list is determined; the device identification information list includes: device identification information of DC controllers that have been found to be connected to the power converter; the device identification information list can be continuously updated according to the search results of the power converter, and the initial content of the device identification information is empty; The construction of the information query request, which includes the specified query sequence number and the maximum timeout time, includes: An information query request is constructed, including the specified query number, the maximum timeout time, and the device identification information list, so that when the DC controller determines that its own device identification information is included in the device identification information list, it can determine that it has received an information query request including the specified query number and has reported its own device identification information.

12. The device search method according to claim 11, characterized in that, After determining that the DC controller corresponding to the recorded device identification information is a DC controller connected to the power converter, the device search method further includes: Add the device identification information of the DC controllers that are connected to the power converter found in this search to the device identification information list; The information query request is reconstructed, including the specified query sequence number, the maximum timeout time, and the latest device identification information list. The information query request is then broadcast again and executed sequentially.

13. The device search method according to claim 8, characterized in that, The feedback information also includes the signal strength of the communication link between the DC controller and the power converter; The step of determining, from the received feedback information, the feedback information whose communication quality meets the preset requirements and using it as the target feedback information includes: Feedback information with signal strength greater than the signal strength threshold is used as target feedback information. Alternatively, the feedback information may also include the signal strength and signal-to-noise ratio of the communication link between the DC controller and the power converter; The step of determining, from the received feedback information, the feedback information whose communication quality meets the preset requirements and using it as the target feedback information includes: The link quality is calculated using the signal strength and the signal-to-noise ratio. Determine the feedback information corresponding to link quality exceeding the link quality threshold, and use it as the target feedback information; Alternatively, the feedback information may also include the link quality of the communication link between the DC controller and the power converter; The step of determining, from the received feedback information, the feedback information whose communication quality meets the preset requirements and using it as the target feedback information includes: Determine the feedback information corresponding to link quality values ​​greater than the link quality threshold, and use this as the target feedback information.

14. A device search method, characterized in that, The power system utilizes any one of a plurality of DC controllers in at least a DC string, the power system further comprising a power converter, wherein the input terminal of the DC controller is used to connect to a DC source, and the output terminal of each DC controller is connected in series to the input terminal of the power converter; The device search method includes: Receive the information query request broadcast by the power converter; In the case of a first DC controller receiving an information query request broadcast by the power converter, after receiving the information query request, the controller responds to the information query request by sending feedback information carrying the device identification information of the first DC controller to the power converter, and forwards the information query request within the DC string where the first DC controller is located. In the case where the second DC controller has not received the information query request broadcast by the power converter, based on the forwarded information query request, feedback information carrying the device identification information of the second DC controller is sent back to the power converter, so that the power converter receives the feedback information from each DC controller; from each received feedback information, feedback information whose communication quality meets the preset requirements is determined and used as the target feedback information; the device identification information in the target feedback information is recorded to determine that the DC controller corresponding to the recorded device identification information is: the DC controller that has a connection relationship with the power converter.

15. The device search method according to claim 14, characterized in that, When the information query request includes the specified query number and the maximum timeout period, feedback information carrying the device identification information of the first DC controller is sent to the power converter, including: If it is determined that an information query request including the specified query number has been received and the device identification information of the device itself has been reported, the specified query number is marked to avoid reporting the device identification information of the device itself again. If it determines that it has not received an information query request including the specified query number, or has received an information query request including the specified query number but has not reported its own device identification information, and if it wins the information reply permission, it will report its own device identification information to the power converter within the maximum timeout period.

16. The device search method according to claim 15, characterized in that, When the information query request includes the specified query number, the maximum timeout time, and the device identification information list, determining that the device identification information that has received the information query request including the specified query number and has been reported includes: If the device identification information is found to be included in the device identification information list, it is determined that the device identification information has been received and reported by the device itself, including the specified query number.

17. The device search method according to claim 14, characterized in that, In the case of a second DC controller that has not received an information query request broadcast by the power converter, the device search method further includes: After receiving the forwarded information query request, the information query request is forwarded within the DC string where the second DC controller is located; The information query request based on forwarding, and the feedback information carrying the device identification information of the second DC controller to the power converter, includes: In response to the first information query request forwarded by the first DC controller and the first information query request forwarded by other second DC controllers, the system directly feeds back feedback information carrying the device identification information of the second DC controller to the power converter; or, it determines the first DC controller that forwards the information query request to the second DC controller and feeds back the feedback information carrying the device identification information of the second DC controller to the first DC controller, so that the first DC controller forwards the feedback information carrying the device identification information of the second DC controller to the power converter.

18. The device search method according to claim 14, characterized in that, The feedback information carrying the device identification information of the first DC controller to the power converter includes: Feedback information carrying the device identification information of the first DC controller and the signal strength of the communication link between the first DC controller and the power converter is sent to the power converter, so that the power converter takes the feedback information with a signal strength greater than the signal strength threshold as the target feedback information; Alternatively, feedback information carrying the device identification information of the first DC controller, the signal strength and signal-to-noise ratio of the communication link between the first DC controller and the power converter is sent to the power converter, so that the power converter can use the signal strength and the signal-to-noise ratio to calculate the link quality, determine the feedback information corresponding to the link quality greater than the link quality threshold, and use it as the target feedback information; Alternatively, feedback information carrying the device identification information of the first DC controller and the link quality of the communication link between the first DC controller and the power converter is sent to the power converter, so that the power converter determines the feedback information corresponding to the link quality greater than the link quality threshold and uses it as the target feedback information.

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