Photovoltaic system anti-countercurrent control system and control method thereof

Abstract

The invention discloses an anti-countercurrent control system of a photovoltaic system and a control method of the anti-countercurrent control system, which are characterized in that complex field configuration work is fully automated through a three-stage self-adaptive (baud rate, address and protocol) technology, plug and play in engineering significance is realized, and the sales, installation and after-sales costs are greatly reduced. Two-stage response (flexible regulation and rapid breaking) is adopted, fine control is achieved in the time dimension and the power dimension, and the traditional contradiction between safety and benefits is broken. Through a protocol library mode of integrating a local protocol library and cloud protocol downloading, a single hardware product has lifelong learning and adaptation capabilities, the long tail demand of the market is effectively met, and the life cycle of the product is prolonged. And finally, the comprehensive targets of simple deployment, intelligent control, friendly power grid and low operation and maintenance cost of small distributed photovoltaic systems such as balcony photovoltaic systems and the like are realized.

Description

Technical Field

[0001] This invention relates to the field of distributed photovoltaic power generation technology, and in particular to a photovoltaic system anti-backflow control system and its control method. Background Technology

[0002] With the increasing popularity of micro-distributed photovoltaic (PV) systems, exemplified by balcony PV systems, a large number of distributed power sources are being connected to low-voltage distribution networks. When the PV power generation exceeds the local load consumption, a "backflow" will be generated and injected into the public grid, potentially leading to voltage exceeding limits, power quality deterioration, and safety hazards. Therefore, grid operators typically require the installation of anti-backflow control devices.

[0003] Existing anti-reverse current technologies have the following main shortcomings: First, the control strategy is simplistic, often employing a rigid "disconnect upon detection of reverse current" approach, resulting in wasted photovoltaic power generation resources and frequent grid disruptions due to frequent start-stop cycles. Second, compatibility is poor; the market offers a wide variety of inverter brands and models with varying communication protocols and parameters, leading to complex installation and commissioning of anti-reverse current control devices. This requires manual configuration by professionals, resulting in a poor user experience and high after-sales costs. Third, they lack scalability and cannot adapt to future inverter models.

[0004] Therefore, there is an urgent need for an anti-backflow solution that can intelligently adapt, flexibly control, and is easy to deploy. Summary of the Invention

[0005] The purpose of this application is to provide a photovoltaic system anti-backflow control system and its control method to solve the problems of poor compatibility, complex deployment and single control strategy of existing photovoltaic anti-backflow technologies.

[0006] To address the aforementioned technical problems, this application provides a photovoltaic system anti-reverse current control system, comprising: A photovoltaic panel, an inverter connected to the photovoltaic panel, an anti-reverse current control device communicatively connected to the inverter, and a power grid connected to the anti-reverse current control device, wherein a load is connected between the anti-reverse current control device and the inverter.

[0007] To address the aforementioned technical problems, this application also provides a photovoltaic system anti-reverse current control method, based on any of the photovoltaic system anti-reverse current control systems described above, comprising: Determine the baud rate, address, and protocol for communication with the photovoltaic inverter; The inverter's power generation and the net load power at the grid connection point are obtained through monitoring equipment, and the reverse power is calculated based on the power generation and the net load power at the grid connection point. Set a flexible control threshold and a fast break threshold, wherein the fast break threshold is greater than the flexible control threshold; Determine whether the reverse current power is greater than zero and less than the fast disconnection threshold; If not, determine whether the reverse current power is less than zero or greater than the fast interruption threshold; If the reverse current power is less than zero, it is determined that the inverter has no reverse current, and the inverter is monitored by the monitoring device without intervention; If the reverse current power is greater than the fast disconnection threshold, fast shutdown is performed, and reclosing is performed after a preset delay. If so, determine whether the reverse current power is greater than zero and less than the flexible control threshold; If so, then the inverter should be observed or adjusted. If not, determine whether the reverse current power is greater than the flexible control threshold and less than the fast disconnection threshold; if yes, then perform flexible control on the inverter.

[0008] As a preferred embodiment, a photovoltaic system anti-reverse current control method, wherein determining the baud rate, address, and protocol for communication with the photovoltaic inverter includes: Physical layer parameter adaptation: A list of preset universal baud rates; When the anti-reverse current control device is powered on or triggered for identification, the baud rate is configured to match the inverter according to the baud rate list order; Send a simple, cross-protocol compatible instruction to a broadcast address or a general query address; Listen for serial port responses. If any data that conforms to the byte frame structure and is correctly verified is received within a set time, the current baud rate is determined to be valid and locked. If the serial port does not respond, switch to the next baud rate and return to the step of sending a simple, cross-protocol compatible instruction to the broadcast address or general query address; Output an effective baud rate that matches the target inverter; Link layer parameter adaptation: Preset address scan range; At the locked effective baud rate, start from the beginning of the address range; Send a targeted query command to the current address; If a valid success response with reasonable content is received from the current address, then the current address is deemed valid. If there is no response or the response is incorrect, increment the address and return to the step of sending a targeted query command to the current address; Output a unique communication address that matches the target inverter; Application layer protocol adaptation: The inverter protocol driver library is pre-stored locally in the anti-reverse flow control device; With the established effective baud rate and address, load the local protocol driver in sequence; Communicate with the inverter using dedicated query commands driven by the current protocol; If the response data fully conforms to the format and semantics defined by the current protocol, then the local protocol match is successful; Lock the current protocol driver and complete the full configuration of communication parameters; Output the precise communication protocol used by the inverter and load the corresponding data point mapping table; If the response data does not conform to the format and semantics defined by the current protocol, the local protocol matching fails, and cloud protocol extension is performed.

[0009] As a preferred embodiment, a photovoltaic system anti-reverse current control method, wherein the cloud protocol extension includes: The “feature response” fragments captured in the physical layer parameter adaptation-application layer protocol adaptation step are uploaded to the cloud server through the 4G / Wi-Fi network module in the anti-backflow control device. The cloud server matches the protocol in a more comprehensive global protocol library or has it analyzed by experts to generate corresponding new protocol driver files. Download and securely verify the protocol driver file, and save it to the local protocol library; The application layer protocol adaptation step is automatically returned, and the new protocol driver is used to re-identify the protocol until success is achieved. Output the updated local protocol library and the new protocol driver that is successfully matched.

[0010] The solution requires further elaboration. A photovoltaic system anti-reverse current control method, wherein obtaining the inverter's power generation and the net load power at the grid connection point through monitoring equipment includes: The bidirectional metering module built into the anti-reverse current control device samples and calculates the voltage and current at the grid connection point in real time to obtain the net load power of the grid connection point. Through the established adaptive communication link, the inverter's power generation is read in real time according to the identified protocol; The solution requires further detailed explanation of a photovoltaic system anti-reverse current control method, wherein the rapid shutdown and reclosing after a preset delay include: The core processor in the anti-backflow control device sends a millisecond-level interruption signal to the fast interruption execution unit. The rapid disconnection of the execution unit completely disconnects the photovoltaic system from the power grid electrically; When the load increases and the photovoltaic system detects no risk of reverse current, the power limit can be gradually lifted or relaxed. After the reverse flow conditions disappear and after a preset delay, the reclosing can be performed automatically or manually to restore grid connection.

[0011] Compared with the prior art, the photovoltaic system anti-reverse current control system and control method provided by the present invention have at least the following beneficial effects: To address the challenges of complex configuration and high installation barriers in anti-reverse current control devices caused by the wide variety of photovoltaic inverter brands and models on the market, as well as differences in communication protocols, baud rates, and device addresses, this invention utilizes innovative "three-level adaptive" (baud rate, address, protocol) technology. This enables the anti-reverse current control device to automatically identify and adapt to the vast majority of inverters, achieving true "plug and play" and zero-configuration deployment. This significantly reduces installation and maintenance costs and reliance on professional personnel.

[0012] (1) Achieving intelligent and refined control strategies: Addressing the problems of wasted power generation resources, frequent grid disruptions, and poor user experience caused by the rigid "detect and disconnect" control mode of traditional anti-reverse flow schemes, this invention proposes a "two-level response" mechanism. By setting flexible regulation thresholds and rapid disconnection thresholds, when reverse flow is detected, a communication-based flexible power regulation strategy is prioritized to smoothly reduce inverter output and eliminate the reverse flow; rapid electrical disconnection is only executed when the reverse flow exceeds the safety limit. Thus, under the premise of absolutely ensuring grid safety, the online power generation time of the photovoltaic system is maximized, and the user's self-consumption benefits are maximized, achieving a balance between safety and economy.

[0013] (2) Building a sustainable and evolving technological ecosystem: For unknown new inverter models that may appear during the product lifecycle, this invention integrates an extended mechanism of "local protocol library + cloud protocol download" to enable the anti-reverse current control device to have remote learning and updating capabilities. This ensures that the system can not only adapt to the current mainstream equipment on the market, but also adapt to new equipment in the future through cloud services, thereby extending the product technology lifecycle and improving the system's sustainability and market competitiveness.

[0014] In summary, this invention aims to provide a complete solution from intelligent sensing (automatic adaptation), intelligent decision-making (hierarchical control) to intelligent evolution (cloud updates), ultimately achieving the comprehensive goals of simplifying the deployment, intelligentizing control, making grid-friendly, and reducing the cost of operation and maintenance of small distributed photovoltaic systems such as balcony photovoltaic systems. Attached Figure Description

[0015] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0016] Figure 1 This is a schematic diagram of a photovoltaic system anti-backflow control system provided in an embodiment of this application; Figure 2 A simplified flowchart of a photovoltaic system anti-backflow control method provided in this application embodiment; In the diagram: 1. Photovoltaic panel; 2. Inverter; 3. Anti-reverse current control device; 4. Power grid; 5. Load. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0018] The core of this application is to provide a photovoltaic system anti-backflow control system and its control method, which solves the problems of poor compatibility, complex deployment and single control strategy of existing photovoltaic anti-backflow technologies.

[0019] Figure 1 This is a schematic diagram of a photovoltaic system anti-backflow control system provided in an embodiment of this application. Figure 2 A simplified flowchart of a photovoltaic system anti-reverse current control method provided in this application embodiment is shown below. Figures 1 to 2 As shown.

[0020] Example 1 A photovoltaic system anti-backflow control system includes: The system comprises a photovoltaic panel 1, an inverter 2 connected to the photovoltaic panel 1, an anti-reverse current control device 3 communicatively connected to the inverter 2, and a power grid 4 connected to the anti-reverse current control device 3. A load 5 is connected between the anti-reverse current control device 3 and the inverter 2. The inverter 2 and the anti-reverse current control device 3 communicate via RS-485 or wirelessly. When the distance is short and wiring is convenient, a wired RS-485 connection can be used; otherwise, a wireless connection is used.

[0021] The anti-backflow control device 3 (master unit) integrates a bidirectional metering module, a core processor (with computing and control functions), and a 4G / Wi-Fi network module. Inverter 2 (slave unit) is the object being monitored and regulated. In actual operation, there is also a cloud protocol library service: providing long-tail support and updates for protocol-driven operations.

[0022] Example 2 A photovoltaic system anti-reverse current control method, based on any one of the above-mentioned photovoltaic system anti-reverse current control systems, includes the following steps: Determine the baud rate, address, and protocol for communication with photovoltaic inverter 2.

[0023] The power generation of inverter 2 and the net load power at the grid connection point are obtained through monitoring equipment, and the reverse power is calculated based on the power generation and the net load power at the grid connection point. Set a flexible control threshold and a fast break threshold, with the fast break threshold being greater than the flexible control threshold; Determine whether the reverse current power is greater than zero and less than the fast break threshold; If not, determine whether the reverse current power is less than zero or greater than the fast disconnection threshold; If the reverse current power is less than zero, it is determined that there is no reverse current in inverter 2, and inverter 2 is monitored by the monitoring equipment without intervention. If the reverse current power is greater than the fast interruption threshold, fast shutdown is performed, and reclosing is performed after a preset delay. If so, determine whether the reverse current power is greater than zero and less than the flexible control threshold; If so, then observe or adjust inverter 2. If not, determine whether the reverse current power is greater than the flexible control threshold and less than the fast disconnection threshold; if yes, then perform flexible control on inverter 2.

[0024] Specifically, Phase 1: Fully Automated Establishment of Communication Links (Plug and Play Foundation) The goal of this stage is to establish reliable data communication with any unknown inverter model with zero configuration, which is a prerequisite for all subsequent advanced functions.

[0025] Step 1.1: Physical Layer Parameter Adaptation (Baud Rate Scan) Input: A list of preset general baud rates (e.g., [1200, 2400, 9600, 19200, 38400, 57600, 115200]).

[0026] process: 1. When the anti-backflow control device 3 is powered on or triggered for identification, it first tries the most commonly used baud rate (such as 9600).

[0027] 2. Send a simple, cross-protocol compatible instruction (such as "read the holding register at address 0x0000" in Modbus RTU format) to the broadcast address or general query address.

[0028] 3. Listen for serial port responses. If any data that conforms to the byte frame structure and is correctly verified is received within the timeout period, the current baud rate is determined to be valid and locked.

[0029] 4. If the serial port does not respond, switch to the next baud rate in the list order and repeat steps 2-3.

[0030] 5. Output: Effective baud rate matched to the target inverter.

[0031] Step 1.2: Link Layer Parameter Adaptation (Device Address Discovery) Input: Preset address scan range (e.g., Modbus slave address 1-247).

[0032] process: 1. At the locked effective baud rate, start from the beginning of the address range.

[0033] 2. Send a targeted query instruction (a more specific "read register" instruction) to the current address.

[0034] 3. If a valid success response is received from the current address (e.g., the returned power value is within the normal range), the current address is considered valid.

[0035] 4. If the address does not respond or responds with an error (such as returning an exception code), the address is incremented, and steps 2-3 are repeated.

[0036] 5. Output: The unique communication address of the target inverter.

[0037] Step 1.3: Application Layer Protocol Adaptation (Protocol Identification) Input: Pre-stored locally in the inverter protocol driver library in the anti-reverse flow control device 3.

[0038] process: 1. Load the local protocol drivers in sequence, given the established effective baud rate and address.

[0039] 2. Communicate with the inverter using the dedicated query instructions defined by the current driver (such as reading a specific manufacturer's register or querying a model string).

[0040] 3. If the response data fully conforms to the format and semantics defined by the current protocol (such as correctly parsing the known manufacturer identifier and product model), then the protocol matching is successful.

[0041] 4. Lock the current protocol driver and complete the full configuration of communication parameters.

[0042] Output: The precise communication protocol used by the inverter, and the corresponding data point mapping table (such as the register address of the power generation and status code).

[0043] If the response data does not conform to the format and semantics defined by the current protocol, the local protocol matching fails, and cloud protocol extension is performed.

[0044] Step 1.4: Cloud Protocol Extension (Backup and Evolution) Triggering condition: Local protocol library traversal and matching failed.

[0045] process: 1. The "characteristic response" fragments captured in steps 1.1-1.3 are uploaded to the cloud server via the 4G / Wi-Fi network module in the anti-reverse flow control device. During protocol adaptation, a dedicated query command is sent to communicate with the inverter. When none of the inverter commands in the device match, all response messages communicated with the inverter during this period are uploaded to the cloud server. The "characteristic response" can be understood as the reply message to the dedicated query command.

[0046] 2. The cloud server matches the protocol in a more comprehensive global protocol library or has it analyzed by experts to generate corresponding new protocol driver files.

[0047] 3. Download and securely verify the driver file, and save it to your local protocol library.

[0048] 4. Automatically return to step 1.3, use the new protocol driver to re-identify, until successful.

[0049] Output: Updated local protocol library and new protocol driver that is successfully matched.

[0050] Phase Two: Intelligent Hierarchical Backflow Prevention Control (Core of "Safety and Economy") Building upon the establishment of a reliable data channel in the first phase, this phase focuses on implementing core power management and security protection.

[0051] Step 2.1: Real-time data synchronization monitoring Load-side monitoring: Through the built-in bidirectional metering module of the anti-reverse current control device 3, the voltage and current at the grid connection point are sampled and calculated in real time to obtain the net load power. (Positive values ​​indicate electricity consumption, negative values ​​indicate reverse flow).

[0052] Generation-side monitoring: Through the established adaptive communication link, the inverter's power generation is read in real time according to the identified protocol. .

[0053] Core calculation: Reverse power (when When the value is negative, its absolute value represents the input power from the power grid (this formula is universal). More directly, when the metering module directly detects that the power flow is towards the power grid, it determines that reverse flow has occurred, and its magnitude is... .

[0054] Step 2.2: Hierarchical Judgment and Decision Making Strategy: Set two key thresholds to divide the control response into two levels.

[0055] (Flexible control threshold): Usually the limit of small reverse current allowed by the power grid (e.g., 50W).

[0056] (Rapid Disconnection Threshold): The hard action threshold required by power grid safety regulations (e.g., 200W), and .

[0057] Decision-making logic: Normal range ( ): Determine that there is no reverse current in inverter 2, and monitor inverter 2 through monitoring equipment without intervention.

[0058] Flexible control range ( ): Entering the regulatory logic.

[0059] like Observe or adjust inverter 2.

[0060] like If so, a Level 1 response will be initiated: flexible regulation.

[0061] Quickly break intervals ( ): Initiate Level 2 response immediately: rapid disconnection.

[0062] Step 2.3: Execution and Feedback Level 1 Response Implementation (Flexible Control): Calculate the target power: .in For a positive safety margin, For load power, This represents the total power consumption of the current local load (unit: watts / W or kilowatts / kW).

[0063] Sending control commands: Sending a command to the inverter via the adaptive communication link to "limit output power to..." The instruction is "...". Modern inverters typically support this type of remote power control function.

[0064] Effect: The inverter smoothly reduces its output. The power generation is reduced to near zero while the system remains connected to the grid, maximizing self-consumption of generated electricity.

[0065] Level 2 response execution (fast breakout): Issue a disconnection command: The core processor in the anti-backflow control device 3 sends a millisecond-level disconnection signal to the fast disconnection execution unit (built-in magnetic latching relay or external circuit breaker control interface).

[0066] Physical isolation: The execution unit operates to completely disconnect the photovoltaic system from the power grid 4 electrically.

[0067] Effect: The reverse flow is terminated instantly, absolutely ensuring the safety of the power grid.

[0068] System status recovery: Recovery after adjustment: When the load increases and the system detects no risk of reverse current, the power limit can be gradually lifted or relaxed.

[0069] Reclosing after disconnection: The reclosing can only be performed automatically or manually to restore grid connection after the reverse current conditions disappear (such as reduced load power or reduced sunlight) and after a preset delay (such as 5 minutes).

[0070] A photovoltaic system anti-reverse current control method fully automates complex on-site configuration through "three-level adaptive" (baud rate, address, protocol) technology, achieving "plug and play" in an engineering sense and significantly reducing sales, installation, and after-sales costs. Employing "two-level response" (flexible regulation, rapid disconnection), it achieves refined control in both time and power dimensions, breaking the traditional contradiction between safety and efficiency. By integrating a protocol library model of "local protocol library + cloud protocol download," it enables individual hardware products to have lifelong learning and adaptation capabilities, effectively addressing long-tail market demands and extending product lifecycles. Ultimately, it achieves the comprehensive goals of simplified deployment, intelligent control, grid-friendly operation, and low-cost operation and maintenance for small-scale distributed photovoltaic systems such as balcony photovoltaic systems.

[0071] To enable those skilled in the art to better understand this solution, the following detailed explanation is provided using specific application scenarios: Example 3: Photovoltaic System for Balcony of High-Rise Apartment Building in the City (Micro Inverter Scenario) 1. Application Scenarios and Configuration Scenario: A user installed a 1.2kW micro inverter on the south-facing balcony of a one-bedroom apartment. The daytime base load (refrigerator, router, etc.) is approximately 80W. Local power grid regulations stipulate that reverse power exceeding 200W must be cut off within 2 seconds.

[0072] Device: An integrated anti-backflow meter with a built-in relay is installed in the indoor distribution box and supports Wi-Fi connectivity.

[0073] Inverter: A new type of micro inverter from a certain brand, with a default communication address of 1, a baud rate of 115200, and using the manufacturer's proprietary protocol.

[0074] Threshold settings: P_set1=50W, P_set2=200W.

[0075] 2. Fully automatic operation process Step 1: Plug and Play Deployment The installer connected the power after completing the wiring. The anti-reverse current meter automatically activates its three-level adaptive function. Complete baud rate scan within 30 seconds and lock onto 115200.

[0076] A quick scan of addresses 1-5 was performed, and the inverter serial number was successfully obtained at address 1.

[0077] The system iterated through the local protocol library and successfully read the model "MICRO -1.2" when it attempted to access the "Brand C Private Protocol" V3, indicating a successful protocol match. No manual configuration was required throughout the process.

[0078] Step Two: Daily Intelligent Control On a sunny morning on a weekday, the photovoltaic power generation was 1.0kW, with a load of 80W.

[0079] Anti-backflow meter detected = 920W> .

[0080] Triggering a secondary response: The anti-reverse current meter controls the built-in relay to disconnect within 100 milliseconds, causing the inverter to shut down due to power outage. This prioritizes the absolute safety of the power grid.

[0081] Step 3: Automatic Recovery and Flexible Control Users return home in the evening and turn on their TVs and computers (load 500W), while the ambient light decreases.

[0082] The meter continuously monitors the circuit, and automatically recloses the circuit breaker after 5 minutes if the recovery conditions are met.

[0083] The inverter restarted, and the power generation dropped to 600W. At this time... = 600W - 500W = 100W.

[0084] because < (100W) ≤ This triggers a Level 1 response.

[0085] The anti-reverse current meter sends a command to the inverter via the established communication link to limit its output power to 450W. = 500W - 50W).

[0086] With the backflow eliminated, the system continues to operate at limited power, neither disconnecting from the grid nor preventing illegal backflow.

[0087] The value of this embodiment lies in demonstrating the principle of prioritizing system safety under stringent power grid regulations, as well as the practicality of flexible control in scenarios with small power fluctuations, achieving fully automated, safe, and compliant operation in the "apartment balcony photovoltaic" scenario.

[0088] Example 4: Hybrid Roof / Balcony System for Suburban Villas (Complex Scenarios and Cloud Adaptation) 1. Application Scenarios and Configuration Scenario: A villa resident has installed a 5kW string inverter, connected to multiple solar panels on the roof and balcony. During the day, the household's base load (water pump, NAS, etc.) fluctuates between approximately 400W and 800W. The grid's allowable reverse current threshold is relatively high, at 500W.

[0089] Device: Rail-mounted anti-backflow controller, with an external 100A AC contactor as the disconnecting unit. Built-in 4G communication module.

[0090] Inverter: A string inverter from a niche brand, with communication parameters of 38400 baud rate, address 3, and using a modified version of the Modbus protocol.

[0091] Threshold setting: =100W, =500W.

[0092] 2. Fully automatic operation process Step 1: Adaptive Obstacle Encounter and Cloud-based Solution After the device is powered on, it successfully adapts to the baud rate (38400) and address (3).

[0093] However, during the protocol adaptation phase, traversing the local library (including standard protocols) failed, and the response data format was incorrect.

[0094] The device automatically uploads the captured response data characteristics (such as the return value of a specific function code) to the manufacturer's cloud protocol platform via the 4G network.

[0095] After comparison by the platform's AI engine, it was identified as "an extension protocol for a niche brand" and the corresponding driver file was distributed.

[0096] The device updated its local library, automatically retried, and successfully identified the inverter model "Niche - Power 5.0". This resolved the compatibility issue for long-tail devices.

[0097] Step 2: Dynamic flexible regulation to cope with power fluctuations On a cloudy day, the photovoltaic power generation capacity fluctuated rapidly between 1kW and 4kW, with a load of approximately 600W.

[0098] When the power generation capacity instantly rises to 3kW ≈ 2400W The system should have been disconnected.

[0099] However, the proactive role of flexible regulation: as the countercurrent rises from 0W to over... During the process, the system has calculated = 600W - 50W = 550W, and issued a power reduction command in advance.

[0100] The inverter output is limited to around 550W, therefore the actual... No breakthrough ever This perfectly avoids frequent start-stop cycles caused by power fluctuations.

[0101] Step 3: Responding to Sudden Load Increases and Releasing Control Measures The user suddenly turned on an instant electric water faucet (load 6kW).

[0102] The net load power detected by the electricity meter instantly changed from -550W (slight backflow) to +5450W (high power consumption).

[0103] The core processor immediately sends a command to the inverter via the communication link to release the power limit and generate full power.

[0104] The inverter boosts its output to its maximum capacity (e.g., 4kW) within seconds to fully support the load and reduce electricity purchases from the grid. This maximizes the revenue generated by the power generation.

[0105] The value of this embodiment lies in demonstrating the system's advanced capabilities in handling complex protocols, fluctuating power, and abrupt load changes. Cloud adaptation addresses the compatibility issues of niche devices; proactive and flexible control avoids unnecessary interruptions; and intelligent linkage responds to load changes, maximizing cost-effectiveness.

[0106] The core of this application lies in creating a technical system that deeply couples "full-stack adaptive access" and "two-stage intelligent control." It revolutionizes the entire process of photovoltaic anti-reverse current equipment, from deployment and sensing to decision-making and execution: at the access layer, through a three-level adaptive approach of "physical layer-link layer-application layer," it achieves zero-configuration, intelligent connection with unknown inverters. At the control layer, through a two-stage hierarchical strategy of "flexible control first, rapid disconnection as a fallback," it maximizes the economic efficiency of photovoltaic power generation under the hard constraints of grid security.

[0107] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and incorporate common knowledge or customary techniques in the art disclosed herein. The specification and examples are to be considered exemplary only, and the true scope of this application is indicated by the claims.

[0108] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The above embodiments of this application do not constitute a limitation on the scope of protection of this application.

Claims

1. A photovoltaic system anti-backflow control system, characterized in that, include: A photovoltaic panel (1), an inverter (2) connected to the photovoltaic panel (1), an anti-reverse current control device (3) connected to the inverter (2) in communication, and a power grid (4) connected to the anti-reverse current control device (3). A load (5) is connected between the anti-reverse current control device (3) and the inverter (2).

2. A photovoltaic system anti-backflow control method, based on the photovoltaic system anti-backflow control system of claim 1, characterized in that, include: Determine the baud rate, address, and protocol for communication with the photovoltaic inverter (2); The power generation of the inverter (2) and the net load power of the grid connection point are obtained by the monitoring equipment, and the reverse power is calculated based on the power generation and the net load power of the grid connection point. Set a flexible control threshold and a fast break threshold, wherein the fast break threshold is greater than the flexible control threshold; Determine whether the reverse current power is greater than zero and less than the fast disconnection threshold; If not, determine whether the reverse current power is less than zero or greater than the fast interruption threshold; If the reverse current power is less than zero, it is determined that the inverter (2) has no reverse current, and the inverter (2) is monitored by the monitoring device without intervention; If the reverse current power is greater than the fast disconnection threshold, fast shutdown is performed, and reclosing is performed after a preset delay. If so, determine whether the reverse current power is greater than zero and less than the flexible control threshold; If so, then the inverter (2) is observed or adjusted. If not, determine whether the reverse current power is greater than the flexible control threshold and less than the rapid disconnection threshold; If so, the inverter (2) is flexibly regulated.

3. The photovoltaic system anti-reverse current control method according to claim 2, characterized in that, The determination of the baud rate, address, and protocol for communication with the photovoltaic inverter (2) includes: Physical layer parameter adaptation: A list of preset universal baud rates; When the anti-reverse flow control device (3) is powered on or triggered for identification, the baud rate matching the inverter (2) is configured according to the baud rate list order; Send a simple, cross-protocol compatible instruction to a broadcast address or a general query address; Listen for serial port responses. If any data that conforms to the byte frame structure and is correctly verified is received within a set time, the current baud rate is determined to be valid and locked. If the serial port does not respond, switch to the next baud rate and return to the step of sending a simple, cross-protocol compatible instruction to the broadcast address or general query address; Output an effective baud rate that matches the target inverter; Link layer parameter adaptation: Preset address scan range; At the locked effective baud rate, start from the beginning of the address range; Send a targeted query command to the current address; If a valid success response with reasonable content is received from the current address, then the current address is deemed valid. If there is no response or the response is incorrect, increment the address and return to the step of sending a targeted query command to the current address; Output a unique communication address that matches the target inverter (2); Application layer protocol adaptation: The inverter (2) protocol driver library is stored locally in the anti-reverse flow control device (3); With the established effective baud rate and address, load the local protocol driver in sequence; Communicate with the inverter (2) using a dedicated query command driven by the current protocol; If the response data fully conforms to the format and semantics defined by the current protocol, then the local protocol match is successful; Lock the current protocol driver and complete the full configuration of communication parameters; The output inverter (2) uses the precise communication protocol and loads the corresponding data point mapping table; If the response data does not conform to the format and semantics defined by the current protocol, the local protocol matching fails, and cloud protocol extension is performed.

4. The photovoltaic system anti-reverse current control method according to claim 3, characterized in that, The cloud protocol extension includes: The "feature response" fragment captured in the physical layer parameter adaptation-application layer protocol adaptation step is uploaded to the cloud server through the 4G / Wi-Fi network module in the anti-reverse flow control device (3); The cloud server matches the protocol in a more comprehensive global protocol library or has it analyzed by experts to generate corresponding new protocol driver files. Download and securely verify the protocol driver file, and save it to the local protocol library; The application layer protocol adaptation step is automatically returned, and the new protocol driver is used to re-identify the protocol until success is achieved. Output the updated local protocol library and the new protocol driver that is successfully matched.

5. The photovoltaic system anti-reverse current control method according to claim 2, characterized in that, The process of obtaining the power generation of the inverter (2) and the net load power at the grid connection point through monitoring equipment includes: The voltage and current of the grid connection point are sampled and calculated in real time by the bidirectional metering module built into the anti-reverse flow control device (3) to obtain the net load power of the grid connection point. Through the established adaptive communication link, the power generation of the inverter (2) is read in real time according to the identified protocol.

6. The photovoltaic system anti-reverse current control method according to claim 5, characterized in that, The step of performing rapid shutdown and reclosing after a preset delay includes: The core processor in the anti-backflow control device (3) sends a millisecond-level interruption signal to the fast interruption execution unit; The rapid disconnection of the execution unit action completely disconnects the photovoltaic system from the power grid (4) electrically; When the load (5) increases, the power limit can be gradually lifted or relaxed after the photovoltaic system detects no risk of reverse current. After the reverse flow conditions disappear and after a preset delay, the reclosing can be performed automatically or manually to restore grid connection.

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