Rapid communication and redundancy control method for AGC substation of distributed photovoltaic power station

Abstract

The invention discloses a rapid communication and redundancy control method for an AGC substation of a distributed photovoltaic power station, and the method comprises the following steps: S1, receiving an automatic power generation control instruction from a power grid dispatching system in parallel and uploading real-time operation data of the photovoltaic power station through two independent communication links; according to the invention, the reliability and robustness of the system are fundamentally improved; by constructing a physical basis of parallel work of two paths of independent communication links and combining real-time state monitoring and a millisecond-level rapid switching mechanism, the method thoroughly changes the fragile situation that the whole substation is disconnected and the function is paralyzed due to a single communication channel or a power supply fault of a traditional system; when the main optical fiber link is interrupted due to construction damage or equipment failure, the system can automatically and seamlessly switch all communication services to the standby Ethernet or wireless link without depending on manual intervention, and it is ensured that the transmission path of the scheduling control instruction is always smooth.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automatic control of power systems, in particular to a distributed photovoltaic power station AGC substation fast communication and redundant control method. BACKGROUND

[0002] According to relevant influences, the distributed photovoltaic installed capacity in some areas has increased sharply, and a large number of 10kV grid-connected power stations are in an "uncontrolled" state. The randomness and volatility of their power generation output pose a serious threat to the safe and stable operation of the power grid. It has become an urgent need for power grid dispatching to realize group control of these distributed photovoltaics.

[0003] Existing AGC control methods are mostly for large centralized power stations, and their communication networks are stable, controllable, and have a limited number of points. However, distributed photovoltaic power stations are numerous, scattered, and have uneven communication conditions. The existing methods face serious challenges: first, the reliability of a single communication link is low, and once it is interrupted, the substation "loses contact" and the control chain is broken; second, the traditional serial data processing method cannot meet the fast response requirements of large-scale power station group control, and the command issuance delay is high; finally, there is a lack of effective redundant switching mechanism, and the system has poor recovery capability when encountering single-point faults such as communication or power supply, and the control continuity cannot be guaranteed. SUMMARY

[0004] To solve the above technical problems, the present application provides a distributed photovoltaic power station AGC substation fast communication and redundant control method.

[0005] The distributed photovoltaic power station AGC substation fast communication and redundant control method comprises the following steps: S1: Through two independent communication links, automatically receive the automatic generation control instructions from the power grid dispatching system and upload the real-time operation data of the photovoltaic power station in parallel; S2: In the dual-core processor of the master control unit, the first processor core executes the analysis and control strategy calculation of the AGC instructions, and the second processor core executes the data exchange management with the communication link and the local photovoltaic inverter; S3: Based on the analyzed control strategy, generate control instructions for each photovoltaic inverter, and issue them to the corresponding photovoltaic inverter through the master control unit; S4: Real-time monitor the on-off state of the two-way communication link and the dual-power supply state of the master control unit; S5: When the main communication link is interrupted or the main power supply fails, automatically switch to the standby communication link or be independently powered by the standby power supply within less than one control cycle to ensure continuous execution of the control instructions.

[0006] As a further technical solution of the present application, in step S1, the double independent communication links include one optical fiber communication link based on IEC 61850 protocol and one Ethernet communication link based on Modbus TCP protocol.

[0007] As a further technical solution of the present application, in step S2, the control strategy calculation includes: based on fuzzy calculation algorithm, the output of the photovoltaic power station is predicted, and combined with the grid scheduling demand and the regional grid carrying capacity, the power adjustment amount of each photovoltaic inverter is calculated.

[0008] As a further technical solution of the present application, after step S5, it further includes step S6: recording and analyzing the instruction execution effect and system switching event, and distributing the income of group regulation and control according to the preset evaluation system.

[0009] In summary, the present application includes the following at least beneficial technical effects: In terms of system reliability and robustness, the present application has achieved fundamental improvement; by constructing the physical basis of double independent communication links working in parallel, and combining real-time state monitoring and millisecond-level fast switching mechanism, this method completely changes the fragile situation of traditional system that the whole substation is "lost" and function paralysis due to single communication channel or power failure; when the main optical fiber link is interrupted due to construction damage or equipment failure, the system can automatically and seamlessly switch all communication services to the standby Ethernet or wireless link without relying on manual intervention, ensuring that the transmission path of the dispatching control instruction is always smooth; similarly, the double redundant power supply design cooperates with the fast electronic switching circuit, which can cope with abnormal situations such as power fluctuations or single power module failure, and provides uninterrupted energy supply for the substation hardware; this inherent redundancy feature makes the system have high fault tolerance and continuous service capability when facing the common and unpredictable single-point failure in distributed environment, greatly enhancing the overall reliability and robustness of the group regulation and control system; In terms of control real-time and response speed, the application realizes a qualitative leap; the core is to adopt the architecture of dual-core processor parallel processing, to physically separate and synchronously execute the I / O intensive tasks of communication management and the computing intensive tasks of strategy calculation; the communication management core is responsible for data transmission and reception with the dispatching master station and the local inverter, checking and protocol conversion, to ensure efficient use of communication interface and low delay of data flow; at the same time, the strategy calculation core can concentrate on running complex fuzzy prediction algorithm, power grid carrying capacity analysis and power distribution calculation without disturbance; this parallel task processing mode avoids the time overhead and resource competition introduced by single-core processor switching between multiple tasks, so that the whole closed-loop processing time from receiving dispatching instructions to generating and issuing specific control instructions is greatly compressed, which can meet the response demand of seconds or even sub-seconds of the power grid for fast power regulation of distributed photovoltaic, effectively suppressing the rapid fluctuation of photovoltaic power; In terms of control intelligence and decision scientificity, the application introduces advanced prediction and optimization algorithms; the method is no longer limited to simply forwarding and executing dispatching instructions, but can accurately predict the short-term power generation output of photovoltaic power station group based on historical data, real-time weather information and power grid operation state through integration of artificial intelligence technologies such as fuzzy calculation; on this basis, the system can intelligently decompose the macro dispatching instructions into fine control strategies suitable for each photovoltaic inverter in the region, taking into account economy and safety; this not only improves the control of renewable energy uncertainty, changes the control behavior from "passive response" to "active foresight", but also optimizes the power distribution in the region, fully taps the control potential of distributed photovoltaic, and improves the consumption capacity and operation stability of the local power grid; In terms of system efficiency and scalability, the application constructs a complete management and control loop; the method covers the whole process from instruction reception, intelligent decision, redundant execution to effect evaluation and benefit distribution; detailed operation data recording and control effect post-evaluation mechanism provides a solid data foundation for continuous optimization of control strategy parameters, fair quantification of the contribution of each photovoltaic power station and benefit distribution accordingly; this transparent and fair mechanism helps to mobilize the enthusiasm of distributed power owners to participate in power grid interaction; at the same time, the modular design concept of the method makes it flexible to adapt to photovoltaic power station groups of different scales and different communication conditions, providing a replicable and scalable technical framework and solution for coordinated control of massive distributed energy in the future power grid. DETAILED DESCRIPTION

[0010] In order to make the purpose, technical scheme and advantages of the embodiments of the application clearer, the technical scheme of the application will be described clearly and completely below with reference to the embodiments.

[0011] The application overcomes the deficiencies of the prior art and provides a distributed photovoltaic power station AGC substation fast communication and redundant control method.

[0012] The application is further described in detail below in combination with embodiments.

[0013] The application designs a distributed photovoltaic power station AGC substation fast communication and redundant control method, including the following steps: S1: parallel double-link data communication; The AGC substation simultaneously performs data interaction with the dispatching master station through two physically and logically independent communication links. For example, link A adopts an optical fiber network based on the IEC 61850 protocol as a main communication channel, and link B adopts an industrial Ethernet based on the Modbus TCP protocol as a backup channel. The substation receives AGC instructions issued by the dispatching in parallel through the two links and simultaneously uploads real-time operation data of the substation and the inverters under its jurisdiction. This parallel mechanism lays a foundation for fast switching and avoids the delay caused by serial detection; S2: dual-core parallel task processing; The dual-core processor of the substation master unit performs parallel processing on the received data. The first processor core (computing core) is specially responsible for core control tasks: analyzing AGC instructions and running group dispatching and group control strategy algorithms (such as power generation output prediction based on fuzzy calculation, power grid carrying capacity analysis, and power distribution calculation) to generate specific control instruction sets. The second processor core (communication management core) is specially responsible for internal and external data exchange: managing the receiving and sending queues of the two communication links and communicating with local photovoltaic inverters (such as collecting data and issuing instructions through the RS485 bus). This task separation parallel processing architecture effectively avoids communication I / O occupying computing resources and greatly shortens the response time from receiving instructions to generating control results; S3: control instruction distribution and execution; The control instructions generated by the first processor core are transmitted to the second processor core through the internal high-speed bus, and then issued to each target photovoltaic inverter through the corresponding communication interface (such as the CAN bus or Ethernet), so as to realize fast and accurate adjustment of the output power of the inverters. S4: real-time monitoring of system state; A separate monitoring process is established to continuously and real-timely monitor the state of key components, including monitoring the signal quality and connection state (on / off) of the two communication links, monitoring the input voltage and working state of the dual-path power supply module, and monitoring the working state of the dual-core processor. All status information is collected to the master unit, which provides the basis for the redundancy switching decision.

[0014] S5: fast and seamless redundancy switching; This is the core step to achieve high reliability; when the status monitoring system detects that the main communication link (link A) is interrupted or the main power supply fails, the system will not wait for a complete communication timeout period; but immediately (in less than a typical control period, such as seconds) trigger the switching logic; Communication switching: immediately switch all data transmission tasks from the failed main communication module to the normal standby communication module, seamlessly connect the business, and the dispatching master station is almost unaware; Power switching: immediately transfer the system power supply load to the normal standby power supply module, ensuring continuous and stable operation of the device; Through this step, it is ensured that in any single communication or power failure scenario, the group dispatching and group control function will not be interrupted; S6 (optional): effect evaluation and benefit allocation; The system records the execution of each control instruction, switching events, and the final power regulation effect; Based on these data, the control effect is evaluated through a preset evaluation model, and according to the evaluation results, a fair benefit allocation algorithm is used to compensate or allocate benefits to the photovoltaic power stations participating in the control, thereby encouraging photovoltaic power stations to actively participate in grid control.

[0015] System initialization and communication link establishment After the system is powered on, the AGC substation first performs hardware self-checking to confirm that the dual-core processor, dual communication module and dual power module are working properly; then, the system starts the communication initialization process: Main communication link establishment: the main communication module (for example, the module located in slot A) is activated, which uses the IEC 61850 protocol to establish a connection with the secure access area of the dispatching data network through the SC / LC single-mode optical fiber interface; this link is set as the default data transmission channel; Standby communication link establishment: almost at the same time, the standby communication module (for example, the module located in slot B) is initialized, which can use the Modbus TCP protocol to connect to the standby access point of the dispatching center through the RJ-45 Ethernet interface or establish a connection through the wireless private network; the initial state of this link is hot standby, which continuously maintains the link handshake signal, but does not carry the main business data; Local communication link establishment: the substation establishes communication connection with each photovoltaic inverter in the station through its built-in RS485 interface or industrial Ethernet interface according to the preset address table, and periodically collects DC voltage, AC power, operating status and other data; Data reception and parallel processing flow Data reception: The AGC command (usually the total regional regulation power value) issued by the power grid dispatch center is simultaneously sent to the main and backup communication links; the two communication modules of the AGC substation receive the command data packet in parallel and perform cyclic redundancy check; after the check passes, the data is temporarily stored in the dual-port memory; Dual-core task allocation and processing: Communication Management Core (Second Core): Responsible for managing all communication-related I / O operations; it continuously polls the receive buffers of the two communication modules to ensure that instruction data is completely acquired; at the same time, it is also responsible for packaging the aggregated real-time inverter data and uploading it to the dispatch center in parallel through the primary and backup links; Strategy Calculation Core (First Core): Dedicated to performing control strategy calculations; once a new AGC instruction is obtained from shared memory, it immediately starts the control algorithm; the algorithm first uses a fuzzy calculation model based on historical power generation data, real-time irradiance and weather forecast information to predict the power output curve of this power station group in the near future; then, it integrates and analyzes the dispatch instructions with the prediction results and real-time power flow data of the power grid to calculate the power value that each photovoltaic inverter in the region needs to adjust, and generates a specific, executable sequence of control instructions; Control command distribution and execution The strategy calculation core writes the generated control instruction sequence into the instruction queue; the communication management core reads the instructions from the queue and distributes them to the corresponding photovoltaic inverters through the local communication network (such as RS485 bus); after receiving the instructions, the inverter adjusts its power output and feeds back the new operating status to the AGC substation, thus completing a basic control cycle; Real-time system status monitoring A separate, high-priority monitoring thread runs in the system, monitoring the following: Communication status: Continuously send heartbeat packets to the scheduling master station and monitor the round-trip delay and packet loss rate of the primary and backup links; if the heartbeat of the primary link times out or the delay exceeds the threshold (e.g., 500ms) for a continuous period of time, it is determined to be abnormal; Power status: Real-time monitoring of the output voltage and current of the dual power supply modules; if a drop in main power supply voltage or power failure is detected, the fault is recorded immediately; Hardware resources: Monitor the load rate, memory usage, and core temperature of the dual-core processor to ensure that the system is not overloaded; Fast redundancy switching mechanism When the status monitoring module detects a fault, the switching logic is immediately triggered: Communication link switching: If the main communication link fails, the system will block the data transmission and reception of the main communication module within milliseconds and seamlessly switch all communication services (including receiving dispatch instructions and uploading power plant data) to the backup communication module; the dispatch master terminal may only perceive a brief data jitter, but the control connection will not be interrupted; Power switching: If the main power supply fails, the backup power module can take over the entire load within microseconds. Because it is a hot backup mode, the voltage output is uninterrupted, ensuring the continuous and stable operation of the substation hardware without restarting. Control loop and post-evaluation At the end of each control cycle, the system will perform a post-evaluation process: Command execution effect analysis: Compare the deviation between the actual output of the inverter and the output required by the command, and calculate the response time and adjustment accuracy; Data recording and uploading: All process data of this control, including original instructions, calculation process, issued instructions, actual feedback, switching events (if any), etc., are encrypted and stored in local non-volatile memory, and uploaded to the data center when appropriate; Strategy optimization and revenue distribution: Long-term data is used to train and optimize the fuzzy prediction model; at the same time, based on accurate instruction execution records, revenue is fairly distributed to different photovoltaic power plants participating in the regulation according to the preset contribution model, thereby incentivizing them to actively cooperate with grid dispatch. Through the detailed steps described above, this invention achieves fully automated and intelligent control of the entire process from instruction reception, intelligent decision-making, reliable execution to effect evaluation, providing a specific and feasible technical implementation plan for the safe and efficient grid connection of large-scale distributed photovoltaic power.

[0016] Working principle A systematic control mechanism of "parallel reception, dual-core processing, real-time monitoring, and rapid switching" enables reliable and rapid regulation of distributed photovoltaic power station clusters; its specific workflow is as follows: After the system is started, the AGC substations deployed in each photovoltaic power station first establish communication connections with the power grid dispatch center and local photovoltaic inverters; the substations maintain parallel connections with the dispatch center through two physically independent communication links with different protocols (such as a primary fiber optic link and a backup Ethernet link); this dual-link architecture constitutes the physical basis for reliable communication of the system; When the dispatch center issues a group dispatch and control command, the command is received in parallel to the AGC substation via two communication links. The dual-core processor in the substation then starts a parallel processing flow: one processor core (communication management core) is dedicated to communication link management, data verification, and protocol conversion to ensure the complete reception of command data; the other processor core (strategy calculation core) performs command parsing and control strategy calculation simultaneously. The strategy calculation process integrates real-time operating data, historical power generation patterns, and short-term weather forecast information. Through the built-in fuzzy computing algorithm, it accurately predicts the changing trend of photovoltaic power output and comprehensively considers the real-time load of the power grid and the regional carrying capacity to generate an optimal set of specific power control commands for each photovoltaic inverter. During the instruction issuance and execution phase, the strategy calculation core transmits the generated instruction set to the communication management core via the internal high-speed bus, which then distributes it to the target inverter via the local communication network (such as RS485 or CAN bus). The entire data processing and instruction generation process achieves time overlap between communication I / O and complex calculations due to the dual-core parallel architecture, significantly shortening the control cycle. When the system is running stably, an independent status monitoring process runs continuously in the background. This process scans and diagnoses the connectivity of the dual communication links, signal quality, working status of the dual power supplies, and operational health of key hardware units at a high frequency. All monitoring data is aggregated and evaluated in real time to form a "health status profile" of the system. The redundancy switching mechanism is the key to the high reliability of this system. When the status monitoring process detects abnormal conditions such as loss of primary communication link signal, excessive delay, or failure of primary power module, it will not wait for the traditional timeout judgment, but will immediately trigger the switching logic. The system will seamlessly and smoothly switch all communication services to the backup communication link or completely transfer the system power load to the backup power supply in a time much less than a typical control cycle (such as seconds). This rapid switching process is almost imperceptible to the dispatch master station, thereby ensuring the continuous and stable execution of group dispatch and control commands in any single communication or power failure scenario, effectively avoiding the risk of the entire photovoltaic power station group going out of control due to single point of failure of equipment or link. Finally, the system has complete control closed-loop and post-evaluation functions; the execution effect of each control command, including the actual power change of the inverter, the command response time, and the system switching event itself, will be recorded in detail; this data is not only used to judge whether the control target has been achieved in real time, but also provides an objective and quantitative data basis for the subsequent construction of a control effect evaluation system, optimization of control strategy parameters, and even fair distribution of benefits, thereby continuously improving the overall efficiency and economy of group control.

[0017] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.

Claims

1. A method for fast communication and redundant control of AGC substation of distributed photovoltaic power station, characterized in that, characterized in that, The method comprises the following steps: S1: receiving the automatic generation control instruction from the power grid dispatching system and uploading the real-time operation data of the photovoltaic power station through two independent communication links in parallel; S2: in the dual-core processor of the master control unit, the first processor core executes the analysis of the AGC instruction and the calculation of the control strategy, while the second processor core executes the data exchange management of the communication link and the local photovoltaic inverter; S3: based on the analyzed control strategy, generating the regulation and control instruction for each photovoltaic inverter, and issuing it to the corresponding photovoltaic inverter through the master control unit; S4: real-time monitoring of the on-off state of the two-way communication link and the two-way power supply state of the master control unit; S5: when the main communication link is interrupted or the main power supply fails, automatically switch to the standby communication link or independently powered by the standby power supply within less than one control cycle to ensure continuous execution of the control instruction.

2. The distributed photovoltaic power station AGC substation fast communication and redundant control method according to claim 1, characterized in that: In step S1, the two independent communication links include one optical fiber communication link based on IEC 61850 protocol and one Ethernet communication link based on Modbus TCP protocol. 3.The method of claim 1, wherein the method further comprises: In step S2, the control strategy calculation includes: based on the fuzzy calculation algorithm, the output of the photovoltaic power station is predicted, and combined with the power grid dispatching demand and the regional power grid carrying capacity, the power adjustment amount of each photovoltaic inverter is calculated.

4. The distributed photovoltaic power station AGC substation fast communication and redundant control method according to claim 1, characterized in that: After step S5, step S6 is further included: recording and analyzing the instruction execution effect and system switching event, and distributing the income of group regulation and control according to the preset evaluation system.