Distributed inverter anti-countercurrent communication architecture and working method thereof

Abstract

The invention discloses a distributed inverter anti-countercurrent communication architecture and a working method thereof. The architecture comprises an electric meter, K data collectors and a plurality of inverters connected to a power grid. The plurality of inverters are divided into K groups according to set requirements, wherein K is greater than or equal to 2; each data acquisition unit carries out real-time data acquisition and instruction issuing on a corresponding group of inverters, and the K data acquisition units are in one-way anti-reflux communication connection in sequence to form a one-way closed ring communication topology; the electricity meter is in communication connection with the one-way closed ring communication topology, and the electricity meter is suitable for transmitting a detected countercurrent signal to each data collector through the one-way closed ring communication topology. The method has the beneficial effects that the communication synchronism is high, the anti-countercurrent response is consistent, and communication resources and local computing resources are fully utilized. Control competition under the condition that multiple data collectors are asynchronous or data are inconsistent is effectively avoided, it is ensured that anti-countercurrent scheduling decisions are consistent in the whole network, and the concurrent processing capacity is improved.

Description

Technical Field

[0001] This application relates to the field of new energy power generation technology, and in particular to a distributed inverter anti-reverse current communication architecture and its working method. Background Technology

[0002] In existing technologies, backflow prevention control can be broadly classified into three typical forms under different scales and layout conditions, with star and ring networks commonly used as networking methods for data acquisition and transmission.

[0003] In small-scale power plants, where the number of inverters is limited and their capacity is small, anti-backflow meters (such as bidirectional meters or current transformers) often communicate directly with each inverter via RS-485 to detect the active power being fed back to the grid in real time and trigger the inverter to switch from MPPT to power limiting mode, reducing the output to near zero. This approach has a short link and simple structure, and basic anti-backflow control can be completed without configuring a data acquisition unit.

[0004] When the number of inverters increases to a small to medium scale, the industry generally adopts a single data acquisition unit + star topology: anti-backflow meters are connected to a centralized data acquisition unit, which simultaneously polls the data of each inverter and meter via RS-485 bus or power line carrier (MBUS / PLC), makes anti-backflow decisions locally, and uniformly issues power commands to all inverters to achieve coordinated control of the entire station. At this time, the uplink usually goes through Ethernet / fiber to the switch to form a star aggregation; the downlink uses multiple RS-485 or MBUS fan-outs to the equipment, which is convenient for deployment and centralized management, but the applicable scale is still limited due to the limitations of bus bandwidth and single-unit processing capacity.

[0005] When power plants are further expanded and the single-unit data acquisition capability becomes a bottleneck, existing systems often shift to a master-slave architecture with multiple data acquisition units. A ring network or star-shaped fiber optic network is used between the acquisition units to improve reliability and coverage. The master acquisition unit interfaces with the anti-backflow meter and the upper-level EMS, periodically summarizing the inverter and meter data reported by multiple slave acquisition units, centrally executing the anti-backflow algorithm and issuing control commands. The acquisition units often form a ring network with two optical ports or form a star aggregation through a switch, while each acquisition unit still connects to its own inverter and metering / environmental equipment locally via RS-485 or MBUS.

[0006] However, for large-capacity multi-inverter sites, a single data acquisition unit is limited by communication distance and processing capacity, making it difficult to cover the entire site and resulting in poor system scalability. Existing master-slave data acquisition architectures in star and ring topologies share common drawbacks: end-to-end latency and jitter are difficult to control, and cross-node consistency is poor; ring network packets converge to the master hop by hop, leading to long-term overload of near-end links and nodes, and idle resources at the far end, resulting in unbalanced utilization; master-slave communication often relies on the cloud to perform anti-backflow calculations before sending the data, increasing uncertainty in backhaul and cloud-side communication, requiring longer communication times, and underutilizing local computing power. Summary of the Invention

[0007] One objective of this application is to provide a distributed inverter anti-reverse communication architecture that can solve at least one of the defects in the aforementioned background art.

[0008] Another objective of this application is to provide a working method for a distributed inverter anti-reverse communication architecture that can solve at least one of the defects in the above-mentioned background art.

[0009] To achieve at least one of the above objectives, the technical solution adopted in this application is as follows: a distributed inverter anti-reverse current communication architecture, including an electricity meter, a data acquisition unit, and multiple inverters connected to the power grid; the multiple inverters are divided into K groups according to set requirements, where K≥2; the number of data acquisition units is K, each data acquisition unit performs real-time data acquisition and command issuance to a corresponding group of inverters, and the K data acquisition units sequentially establish unidirectional communication connections to form a unidirectional closed-loop communication topology; the electricity meter communicates with the unidirectional closed-loop communication topology, and the electricity meter is adapted to transmit the detected reverse current signal to each data acquisition unit through the unidirectional closed-loop communication topology.

[0010] Preferably, the data packets sent by each of the data collectors have different identifiers; a data transmission cycle is defined as the period from when a single data collector sends an identifier data packet to the unidirectional closed-loop communication topology until it receives its own identifier data packet again.

[0011] Preferably, a single data transmission cycle comprises K consecutive data transmission stages; the data collector is adapted to complete the processing and packaging of its own data within the first K-1 data transmission stages to form an identification data packet for the next data transmission cycle, and then, when looping back its own data in the Kth data transmission stage, it updates the identification data packet of the current loop based on the identification data packet of the next data transmission cycle.

[0012] Preferably, one of the data acquisition units is communicatively connected to the electricity meter; when the electricity meter detects a reverse current signal, a reverse current detection flag is added to the identification data packet of the data acquisition unit connected to the electricity meter, and then the reverse current detection flag is transmitted to each of the data acquisition units through a single data transmission cycle.

[0013] Preferably, the identification data of the data collector includes a frame header, a variable area, a payload area, and a frame tail; the frame header is used to carry protocol identifiers, length, and addressing information, the variable area is used to carry synchronization-related information, the payload area is used to carry service data, and the frame tail is used for frame-level integrity verification.

[0014] Preferably, after receiving data sent by the previous data collector, the data collector waits for a set time before forwarding the data to the next data collector; the variable area is adapted to record and carry time-limited control information for the set waiting time required for data forwarding.

[0015] Preferably, the time-limited control information carried by the variable area during each data forwarding includes the number of times the current data is forwarded, the waiting time for the previous data collector to forward the data, and the receiving time of the previous data collector when it receives the data. When the data collector receives the current data, it calculates the set waiting time required for the current data collector by using the local receiving time and the waiting time for the previous data collector to forward the data recorded in the variable area.

[0016] A method for operating the above-mentioned distributed inverter anti-reverse communication architecture includes the following steps: when one of the data acquisition units detects a reverse current signal, the inverter signal is transmitted to all data acquisition units within one data transmission cycle through a unidirectional closed-loop communication topology; all data acquisition units synchronously send a power reduction signal for anti-reverse current control to all inverters at a selected time base.

[0017] Preferably, based on the data transmission cycle of the reverse signal transmission, the start time of the next data transmission cycle is used as the selected time reference; or, the time delay of the loopback time of the identification data of the data acquisition device that identifies the inverter signal is fixed and used as the selected time reference.

[0018] Preferably, when performing anti-reverse current control, each data acquisition unit calculates the anti-reverse current load reduction power required for the inverter it is responsible for based on the global power data within the data transmission cycle and the local power generation ratio. Then, the calculated anti-reverse current load reduction power is evenly distributed to each inverter it is responsible for to obtain the required power reduction signal.

[0019] Compared with the prior art, the beneficial effects of this application are as follows: This application features strong communication synchronization and consistent anti-backflow response, making full use of communication and local computing resources. Using its own identification data loopback as the period boundary and backflow events synchronized to all nodes via flags, it effectively avoids control competition in situations where multiple data collectors are asynchronous or have inconsistent data, ensuring consistent anti-backflow scheduling decisions across the entire network and improving concurrent processing capabilities. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the basic architecture of this application.

[0021] Figure 2 This is a schematic diagram of the architecture of a complete data transmission cycle in this application.

[0022] Figure 3 This is a schematic diagram of the working timing of the data acquisition device in this application within a single data transmission cycle.

[0023] Figure 4 This is a schematic diagram illustrating the transmission of the reverse flow flag for each data acquisition device in this application.

[0024] Figure 5 This is a schematic diagram of the structure of the data packet in this application.

[0025] In the diagram: Inverter 100, Electricity Meter 200, Data Acquisition Unit 300, Power Grid 400, Switch 500, Network Manager 600. Detailed Implementation

[0026] The present application will now be further described in conjunction with specific embodiments. It should be noted that, in the description of this specification, the use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicates that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0027] In the description of this application, it should be noted that the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., which indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and should not be construed as limiting the specific protection scope of this application.

[0028] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0029] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0030] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0031] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0032] One aspect of this application provides a distributed inverter anti-reverse current communication architecture, such as... Figure 1As shown, one preferred embodiment includes an electricity meter 200, K data acquisition units 300, and multiple inverters 100 connected to the power grid 400. The multiple inverters 100 are divided into K groups according to set requirements, where K ≥ 2. Each data acquisition unit 300 performs real-time data acquisition and command issuance to its corresponding group of inverters 100. The K data acquisition units 300 sequentially establish unidirectional anti-reverse current communication connections to form a unidirectional closed-loop communication topology. The electricity meter 200 communicates with the unidirectional closed-loop communication topology, and the electricity meter 200 can transmit detected reverse current signals to each data acquisition unit 300 through the unidirectional closed-loop communication topology.

[0033] Understandably, the distributed inverter anti-reverse current communication architecture based on a unidirectional closed-loop communication topology provided in this application can achieve efficient collaboration among multiple data acquisition units 300 and improve the robustness of the entire communication architecture. Specifically, by dividing the multiple inverters 100 in the entire station into K groups, each group is responsible for collecting the operating data of the inverters 100 in its group. The data acquisition units 300 are interconnected through a unidirectional closed-loop communication topology, and transmit the locally collected and received global data in a fixed order. This ensures that each data acquisition unit 300 can completely obtain the reverse current status information collected by the inverters 100 and meters 200 in the entire station. Each data acquisition unit 300 autonomously runs an anti-reverse current algorithm locally, independently judges based on global information, and issues power adjustment commands to achieve distributed anti-reverse current control.

[0034] Compared to traditional methods, this application offers strong communication synchronization, consistent anti-backflow response, and full utilization of communication and local computing resources. Using its own identification data loop as the periodic boundary and synchronizing backflow events to all nodes via flags, it effectively avoids control competition in situations where multiple data collectors 300 are asynchronous or have inconsistent data, ensuring consistent anti-backflow scheduling decisions across the entire network and effectively improving concurrent processing capabilities. Furthermore, each data collector 300 only needs to collect data from its own group of inverters 100 and forward it to the next data collector 300. Therefore, the data packet size and forwarding path within the unidirectional closed-loop communication topology are small; and each data collector 300 possesses complete global awareness and independent decision-making capabilities.

[0035] It should be understood that the specific grouping method of multiple inverters 100 can be allocated according to principles such as geographical location or similar capacity; multiple inverters 100 can be connected to the power grid 400 in series and / or parallel. The specific number of inverters 100 in each group can be selected according to the actual needs of those skilled in the art; for ease of understanding, a specific example will be used to describe it in detail below.

[0036] Specifically, such as Figure 1As shown, there are 11 inverters 100 in total, which can be divided into 4 groups, i.e., K takes the value of 4. Group 1 includes 2 inverters 100, and the other 3 groups each include 3 inverters 100. The 4 groups of inverters 100 can be labeled as inverter group #1 to #4 in sequence. Inverter group #1 includes 2 inverters 100, so the 2 inverters 100 in inverter group #1 can be labeled as inverter #1-1 and inverter #2. Similarly, the three inverters 100 in inverter group #2 are labeled as inverter #2-1, inverter #2-2, and inverter #2-3, respectively; the three inverters 100 in inverter group #3 are labeled as inverter #3-1, inverter #3-2, and inverter #3-3, respectively; and the three inverters 100 in inverter group #4 are labeled as inverter #4-1, inverter #4-2, and inverter #4-3, respectively. Correspondingly, there are four data acquisition units 300. The data acquisition unit 300 corresponding to inverter group #1 can be labeled as data acquisition unit #1, the data acquisition unit 300 corresponding to inverter group #2 can be labeled as data acquisition unit #2, the data acquisition unit 300 corresponding to inverter group #3 can be labeled as data acquisition unit #3, and the data acquisition unit 300 corresponding to inverter group #4 can be labeled as data acquisition unit #4.

[0037] It should be understood that the four data acquisition units 300 are connected end-to-end via communication links, forming a unidirectional closed ring topology, enabling the directional sequential transmission of data packets among the data acquisition units 300. The specific method of the communication link can be selected according to the actual needs of those skilled in the art, such as using optical fiber. The data packets generated by each data acquisition unit 300 always flow unidirectionally in the ring link, ensuring system synchronization, clear structure, and effective support for distributed synchronization decision-making and anti-backflow response.

[0038] It's important to understand that to ensure the safe operation of the distributed inverter system, all inverters 100 need to synchronously perform anti-reverse power regulation when reverse current occurs. Since data packets are transmitted unidirectionally in a one-way closed-loop communication topology, when one data acquisition unit 300 collects a reverse current signal, it needs to transmit the data packet carrying the reverse current signal to each data acquisition unit 300. Furthermore, after the transmission of the inverter signal is complete, each data acquisition unit 300 needs a synchronized time base for anti-reverse current control; therefore, a specific data transmission cycle needs to be set. That is, the reverse current signal needs to be transmitted within a single data transmission cycle, and then an appropriate timing should be selected to perform anti-reverse current control on all inverters 100. There are several ways to set the specific data transmission cycle; for ease of understanding, a specific method for setting the data transmission cycle will be given below.

[0039] Specifically, such as Figure 2As shown, the data packets sent by each data collector 300 have different identifiers; a data transmission cycle is defined as the period from when a single data collector 300 sends an identifier data packet to a unidirectional closed-loop communication topology until it receives its own identifier data packet again.

[0040] For ease of understanding, the following will use the aforementioned four data collectors #1 to #4 as examples to describe a single data transmission cycle in detail. For ease of description, the data packet generated by data collector #1 can be identified as data #1, the data packet generated by data collector #2 as data #2, the data packet generated by data collector #3 as data #3, and the data packet generated by data collector #4 as data #4.

[0041] like Figure 2 As shown, at the beginning of the data transmission cycle, data collector #1 receives data #4 and sends its own generated data #1 to data collector #2. Data collector #2 receives data #1 and sends its own generated data #2 to data collector #3. Data collector #3 receives data #3 and sends its own generated data #3 to data collector #4. Data collector #4 receives data #3 and sends its own generated data #4 to data collector #1.

[0042] In the second phase, data collector #1 forwards the data #4 received in the initial phase to data collector #2, data collector #2 forwards the data #1 received in the initial phase to data collector #3, data collector #3 forwards the data #2 received in the initial phase to data collector #4, and data collector #4 forwards the data #3 received in the initial phase to data collector #1.

[0043] In the third stage, data collector #1 forwards the data #3 received in the previous stage to data collector #2, data collector #2 forwards the data #4 received in the previous stage to data collector #3, data collector #3 forwards the data #1 received in the previous stage to data collector #4, and data collector #4 forwards the data #2 received in the previous stage to data collector #1.

[0044] In the final stage, data collector #1 forwards data #2 received in the previous stage to data collector #1, data collector #2 forwards data #3 received in the previous stage to data collector #3, data collector #3 forwards data #4 received in the previous stage to data collector #4, and data collector #4 forwards data #1 received in the previous stage to data collector #1.

[0045] After four stages, the identification data packet generated by each data collector 300 in the initial stage will eventually return to the original sender through the nodes formed by the other three data collectors 300, realizing the data packet loop. At this time, each data collector 300 immediately enters the next new data transmission cycle, re-collects and encapsulates new local data, and starts a new round of data flow. Through this communication method that divides the cycle based on its own data loop, the synchronization of data across the entire network and the complete awareness of the entire site's data by each data collector 300 are ensured, facilitating the consistency of distributed decision-making and anti-backflow control.

[0046] It is important to know that, in order to ensure the continuity of the data transmission cycle, after each data collector 300 completes the distribution of its own identification data packet at the beginning of the current data transmission cycle, it needs to complete the packaging of the new local data for the next data transmission cycle before the end of the current data transmission cycle, so that the data collector 300 can immediately distribute the new identification data packet at the beginning of the next data transmission cycle.

[0047] Specifically, each data acquisition unit 300 is not only responsible for real-time data acquisition from the local inverter 100, but also needs to perform necessary data cleaning, preprocessing, and formatting packaging operations on the acquired raw data to ensure data accuracy and standardization. After sending its own identification data packet for the current data transmission cycle, it immediately starts the data acquisition and packaging process for the next data transmission cycle, completing a new round of data processing and preparation before the current identification data packet returns to the local machine. When the next data transmission cycle begins, the data acquisition unit 300 can immediately encapsulate the latest and complete local data into a new identification data packet and send it to the next node. The identification data packet contains various data types, some of which are immutable data, and some are variable data; therefore, when packaging the identification data packet corresponding to the next data transmission cycle, only the variable data of the current data transmission cycle needs to be updated, thereby improving data packaging efficiency.

[0048] As can be understood from the foregoing, a single data transmission cycle comprises K consecutive data transmission stages. The data collector 300 can process and package its own data within the first K-1 data transmission stages to form the identification data packet for the next data transmission cycle. Then, during the loopback of its own data in the Kth data transmission stage, it updates the loopback identification data packet based on the identification data packet for the next data transmission cycle. For ease of understanding, the following description, using data collector #1 as an example, details the process of issuing and updating its own identification data packet.

[0049] Specifically, such as Figure 2 and Figure 3As shown above, a single data transmission cycle can be divided into four data transmission stages based on the number of data acquisition devices 300: the initial stage, the second stage, the third stage, and the final stage.

[0050] At the beginning of the initial phase, data collector #1 can receive data #4 and send its own data #1 to data collector #2. Throughout the initial phase, data collector #1 will process the received data #4, such as data identification, and prepare for forwarding. During this phase, data collector #1 can also receive and process the data from the inverter 100 in this group in real time.

[0051] At the start of the second phase after the initial phase ends, data collector #1 can receive data #3 and send data #4 to data collector #2; throughout the second phase, data collector #1 will process the received data #3 and prepare it for forwarding; during this phase, data collector #1 can also receive and process the data from the inverter 100 of this group in real time.

[0052] At the beginning of the third phase after the end of the second phase, data collector #1 can receive data #2 and send data #3 to data collector #2. Throughout the third phase, data collector #1 will process the received data #2 and prepare it for forwarding. During this phase, data collector #1 can also receive and process the data from the inverters 100 in this group in real time, and at the end of the second phase, it will complete the packaging of the inverters 100 data in this group to form new data #1 for the next data transmission cycle.

[0053] At the beginning of the final stage after the end of the third stage, data collector #1 can receive the local loopback data #1 and send data #2 to data collector #2; throughout the final stage, data collector #1 will update the loopback data #1 according to the new data #1 that was packaged in the previous stage.

[0054] It is important to understand that reverse current in a distributed inverter system can be detected by a meter 200 located between the grid 400 and the inverter 100. Specifically, meter 200 considers reverse current to have occurred when it detects reverse active power. The specific process by which meter 200 identifies the reverse current signal is well-known to those skilled in the art and will not be elaborated upon here. When meter 200 detects a reverse current signal, it needs to communicate with data acquisition unit 300. Meter 200 can communicate with all or some of the data acquisition units 300. Since anti-reverse current control requires synchronized operation of all inverters 100, to ensure synchronization, the reverse current signal needs to flow once along a unidirectional closed-loop communication topology. Therefore, meter 200 only needs to communicate with one data acquisition unit 300. When the meter 200 detects a reverse current, a reverse current detection flag is added to the identification data packet of the data acquisition unit 300 connected to the meter 200, and then the reverse current detection flag is transmitted to each data acquisition unit 300 through a single data transmission cycle.

[0055] It should be understood that the electricity meter 200 can communicate with any data acquisition unit 300. In this embodiment, it is preferable to connect the electricity meter 200 with the data acquisition unit 300 that has the fewest inverters 100 in the corresponding group. For example Figure 1 As shown, the inverter group #1 corresponding to data acquisition unit #1 contains the fewest inverters 100, so meter 200 can be connected to data acquisition unit #1 for communication. Then, when meter 200 detects a reverse current signal, a reverse current detection flag can be added to data acquisition unit #1. For ease of understanding, the specific process of data acquisition unit #1 connecting to meter 200 and performing reverse current detection flag cycling will be described in detail below.

[0056] Specifically, such as Figure 4 As shown, in the Nth data transmission cycle, if data collector #1 detects reverse current in meter 200, that is, it finds current flowing to the power grid 400 when collecting data locally, then in the subsequent N+1th data transmission cycle, data collector #1 adds a reverse current detection flag to the identification data packet it sends. This data #1 containing the reverse current detection flag ( Figure 4The data is transmitted sequentially through data collectors #2, #3, and #4 along a one-way closed-loop communication topology. Simultaneously, each data collector 300 also completes its own synchronous forwarding of data packets, achieving network-wide data synchronization. The anti-backflow algorithm is activated when each data collector 300 receives a data packet with a backflow detection flag, and its own flag data packet has been looped back to its local unit, ensuring that all data collectors 300 use the same global data view for judgment and response. That is, at the end of the N+1 data transmission cycle, each data collector 300 synchronously activates the anti-backflow algorithm and immediately issues corresponding control commands to its assigned inverters 100, ensuring that anti-backflow measures are uniform across the network and respond promptly, avoiding scheduling conflicts and inconsistencies caused by data asynchrony in distributed sites.

[0057] In this embodiment, the identification data packet of the data collector 300 has various specific structural types. For ease of understanding, a specific structure will be described in detail below. For example... Figure 5 As shown, the identification data of the data collector 300 includes a frame header, a variable area, a payload area, and a frame trailer. The frame header serves as a general control and parsing entry point, carrying protocol identifiers, length, and necessary addressing information to ensure the receiver can quickly locate and correctly interpret subsequent content. The variable area carries synchronization-related information and is a unique extended area specific to this application's technical solution; it can be updated during data packet forwarding. The payload area carries service data, such as power, voltage / frequency, status, and event summaries. The frame trailer is used for frame-level integrity verification; if necessary, an authentication tag can be attached without affecting the organization of the aforementioned segments. Compared to traditional methods, the overall structure of the identification data packet in this application can achieve data forwarding synchronization functionality simply by adding a variable area without altering conventional data frame parsing practices.

[0058] It's important to understand that, to avoid the impact on forwarding synchronization and communication caused by uncontrollable data forwarding delays accumulating at each level, it's necessary to force data collector 300 to wait a fixed time after receiving data before forwarding it. That is, after receiving data from the previous data collector 300, data collector 300 waits a set time before forwarding the data to the next data collector 300. Considering that distributed inverter systems are often installed outdoors and lack network connectivity, preventing time synchronization between data collectors 300, the total forwarding delay time of the data packet throughout the entire data transmission cycle can be set. In layman's terms, theoretically, the waiting time required for data forwarding is T. Within a data transmission cycle, data needs to be forwarded K times. Theoretically, the waiting time for each forwarding needs to be controlled to be T. However, since it is difficult to synchronize the time between the various data acquisition units 300, setting the waiting time T for a single forwarding may cause time synchronization disorder. Therefore, in the technical solution of this application, the total waiting time of the data packet within a data transmission cycle can be set to KT, without needing to set the waiting time for a single forwarding. In this way, it is only necessary to confirm the waiting time when the local loopback occurs.

[0059] It should be understood that, in order to ensure that the total waiting time of a data packet at the end of a single data transmission cycle meets the set value requirement, a variable area can be designed for the data packet. This variable area can record and carry time-limited control information regarding the waiting time required for data forwarding. Thus, even without full network time synchronization, the "received and then forwarded within a time limit" control information can be transmitted along with the packet to the next data collector 300. Furthermore, when data is forwarded to the next node, the forwarding waiting time of the previous node is calculated, and the forwarding waiting time for the current stage is adjusted based on the calculation result.

[0060] Specifically, the time-limited control information carried by the variable area during each data forwarding includes the number of times the current data has been forwarded, the waiting time for the previous data collector 300 to forward the data, and the reception time of the previous data collector 300 when receiving the data. When the data collector 300 receives the current data, it calculates the set waiting time required by the current data collector 300 by comparing the local reception time with the waiting time for the previous data collector 300 to forward the data and the reception time of the previous data collector 300 recorded in the variable area; thereby converging the end-to-end delay of the data in the multi-stage propagation process to near the expected target.

[0061] It is understandable that the set waiting time required by the current data collector 300 can be defined as the current node's waiting time, the waiting time for the previous data collector 300 to forward data can be defined as the previous node's waiting time, and the actual waiting time for the previous data collector 300 to forward data can be defined as the actual time consumed by the previous node. Therefore, the current node's waiting time = set waiting time - (the actual time consumed by the previous node - the previous node's waiting time). For ease of understanding, specific parameters will be used to illustrate this below.

[0062] Specifically, let's assume the data is received at time t. A That is, the local reception time is t A The previous data acquisition unit 300 received this data at time t. B The data identification time within the previous data collector 300 is T1, the actual waiting time for the previous data collector 300 to forward the data is T2, that is, the actual time consumed by the previous node is T2, and the time for the data to be transmitted from the previous data collector 300 to this machine is T3; therefore, t A - t B = T1 + T2 + T3. Where T1 and T3 are known data, so the required T2 can be calculated directly.

[0063] Since the theoretical waiting time for data forwarding is set to a constant value T, the current node's waiting time T4' = T - (T2 - T4) can be calculated; where T4 represents the previous node's waiting time, stored in the variable area of ​​the identifier data packet. After calculating the current node's waiting time T4', the previous node's waiting time in the variable area of ​​the identifier data packet is updated.

[0064] More specifically, assuming T is 10ms, if the previous node's waiting time T4 is 8ms and the previous node's actual time T2 is 10ms, then the calculated waiting time for this node, T4', is 8ms. This means that the local node needs to forward data 2ms earlier than the theoretical waiting time. If the actual time consumed by this node, T2', is 7ms, then the next node's waiting time, T4'' = T - (T2' - T4') = 11ms. This means that the next node's data forwarding waiting time is delayed by 1ms compared to the theoretical waiting time.

[0065] In layman's terms, the actual time consumed by the previous node can be calculated by subtracting the local reception time from the reception time of the previous data acquisition unit 300. Compared to traditional methods, in the anti-backflow and collaborative control scenario of this application, the variable area of ​​the data packet can ensure that each data collector 300 obtains a stable and controllable time window within the fixed process of "receiving - calculating - waiting - forwarding", while also having a self-recovery tendency for abnormal links; and achieves synchronization function with minimal protocol modifications.

[0066] In this embodiment, as Figure 1 As shown, the distributed inverter anti-backflow communication architecture of this application also includes a switch 500. The switch 500 can communicate with a unidirectional closed-loop communication topology and is in bypass mirroring mode, not participating in data forwarding. During the process of the unidirectional closed-loop communication topology sending data packets from upstream to downstream, the switch 500 can monitor the data through mirroring or other methods and upload the monitored data to the network manager 600 so that users can view the working status of the distributed inverter system.

[0067] Another aspect of this application provides a method for operating the above-described distributed inverter anti-reverse communication architecture, wherein a preferred embodiment includes the following steps: when one of the data acquisition units 300 detects a reverse current signal, the inverter signal is transmitted to all data acquisition units 300 within one data transmission cycle through a unidirectional closed-loop communication topology; all data acquisition units 300 synchronously send a power reduction signal for anti-reverse current control to all inverters 100 at a selected time reference.

[0068] Understandably, during anti-reverse current control, each data acquisition unit 300 calculates the anti-reverse current load reduction power required for its assigned inverter 100 based on the global power data within the data transmission cycle and the local power generation ratio. This calculated anti-reverse current load reduction power is then evenly distributed to each assigned inverter 100 to obtain the required power reduction signal. For ease of understanding, the following detailed explanation will use data acquisition unit #1 as an example.

[0069] Specifically, assuming that the total power generation of inverters #1-1 and #1-2 under the responsibility of data acquisition unit #1 accounts for 10% of the local power generation; if inverters #1-1 and #1-2 have the same power rating, then the anti-reverse current load reduction power required for both inverters #1-1 and #1-2 is 5%ΔP, where ΔP represents the total global anti-reverse current load limiting power; if inverters #1-1 and #1-2 have different power ratings, with the power rating of inverter #1-1 being 1.5 times that of inverter #1-2, then the anti-reverse current load reduction power required for inverter #1-1 is 6%ΔP, and the anti-reverse current load reduction power required for inverter #1-2 is 4%ΔP.

[0070] It should be noted that in the technical solution of this application, data forwarding has a strong synchronization mechanism. Therefore, the anti-reverse current commands issued by each data acquisition unit 300 to the corresponding inverter 100 need to be synchronized with a set time base. There are several ways to select the time base; for example, based on the data transmission cycle of the reverse current signal transmission, the start time of the next data transmission cycle can be used as the selected time base; or, the time delay of the loopback time of the identification data of the data acquisition unit 300 that identifies the inverter signal can be fixed as the selected time base.

[0071] Specifically, for the selected time base of using the start time of the next data transmission cycle, such as... Figure 4 As shown, from the moment data collector #1 detects the backflow and sends data #1 containing the backflow detection flag, until the end of the third stage of the current data transmission cycle, data collectors #2 to #4 all receive data #1 containing the backflow detection flag. Therefore, in the final stage of the current data transmission cycle, the four data collectors 300 can complete the preparation of the anti-backflow command and send it at the beginning of the next data transmission cycle.

[0072] For the selected time reference, a fixed time delay is used for the loopback time of the identified data from the data acquisition unit 300 that detects the inverter signal. From the time data acquisition unit #1 detects reverse current and sends data #1 containing the reverse current detection flag until it receives data #1 containing the reverse current detection flag again, a delay of 0.25t, 0.5t, or t is applied to issue the anti-reverse current command, ensuring that each data acquisition unit 300 has sufficient time to prepare the anti-reverse current command; where t represents the duration of a single data transmission cycle.

[0073] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A distributed inverter anti-backflow communication architecture, characterized in that, include: Multiple inverters connected to the power grid; The inverters are divided into K groups according to the set requirements, where K ≥ 2; as well as K data acquisition units; Each of the data acquisition units performs real-time data acquisition and command issuance to a corresponding set of inverters. The K data acquisition units sequentially establish unidirectional communication connections to form a unidirectional closed-loop communication topology. An electricity meter is communicatively connected to the unidirectional closed-loop communication topology, and the electricity meter is adapted to transmit the detected reverse current signal to each of the data acquisition units through the unidirectional closed-loop communication topology.

2. The distributed inverter anti-reverse current communication architecture as described in claim 1, characterized in that, Each of the data acquisition devices sends data packets with different identifiers; a data transmission cycle begins when a single data acquisition device sends an identifier data packet to the unidirectional closed-loop communication topology and ends when it receives its own identifier data packet again.

3. The distributed inverter anti-reverse current communication architecture as described in claim 2, characterized in that, A single data transmission cycle comprises K consecutive data transmission phases; The data collector is adapted to process and package its own data in the first K-1 data transmission stages to form the identification data packet for the next data transmission cycle, and then update the identification data packet of the current loop based on the identification data packet of the next data transmission cycle when performing its own data loopback in the Kth data transmission stage.

4. The distributed inverter anti-reverse current communication architecture as described in claim 2, characterized in that, One of the data acquisition devices is connected in communication with the electricity meter; When the electricity meter detects a reverse current signal, a reverse current detection flag is added to the identification data packet of the data acquisition device connected to the electricity meter, and then the reverse current detection flag is transmitted to each of the data acquisition devices through a single data transmission cycle.

5. The distributed inverter anti-reverse current communication architecture as described in any one of claims 2-4, characterized in that, The identification data of the data acquisition device includes frame header, variable area, load area and frame tail; The frame header carries the protocol identifier, length, and addressing information; the variable area carries synchronization-related information; the payload area carries service data; and the frame tail is used for frame-level integrity verification.

6. The distributed inverter anti-reverse current communication architecture as described in claim 5, characterized in that, After receiving data from the previous data collector, the data collector waits for a set time before forwarding the data to the next data collector; the variable area is adapted to record and carry time-limited control information for the set waiting time required for data forwarding.

7. The distributed inverter anti-reverse current communication architecture as described in claim 6, characterized in that, The time-limited control information carried by the variable area during each data forwarding includes the number of times the current data is forwarded, the waiting time for the previous data collector to forward the data, and the receiving time of the previous data collector to receive the data. When the data collector receives the current data, it calculates the set waiting time required by the current data collector by comparing the local receiving time with the waiting time for the previous data collector to forward data recorded in the variable area and the receiving time of the previous data collector to receive the data.

8. A method for operating the distributed inverter anti-reverse current communication architecture as described in any one of claims 1-7, characterized in that, Includes the following steps: When one of the data acquisition units detects the reverse signal, the inverter signal is transmitted to all the data acquisition units within one data transmission cycle through a unidirectional closed-loop communication topology. All data acquisition units synchronously send a power reduction signal for backflow prevention control to all inverters at the selected time base.

9. The working method of the distributed inverter anti-reverse current communication architecture as described in claim 8, characterized in that, Based on the data transmission cycle of the reverse signal transmission, the start time of the next data transmission cycle is taken as the selected time base. Alternatively, the time delay of the loopback time of the data acquisition device that identifies the inverter signal can be fixed as the selected time reference.

10. The working method of the distributed inverter anti-reverse current communication architecture as described in claim 8, characterized in that, When performing anti-reverse flow control, each data acquisition unit calculates the anti-reverse flow load reduction power required for the inverter it is responsible for based on the global power data within the data transmission cycle and the local power generation ratio. Then, the calculated anti-reverse flow load reduction power is evenly distributed to each inverter it is responsible for to obtain the required power reduction signal.

Images