Dual-link hot-standby redundant water pump constant pressure control system and control method thereof

Abstract

The application provides a double-link hot backup redundancy water pump constant pressure control system and a control method thereof. The system comprises a master controller (PLC1), a slave controller (PLC2), a first control link (L1), a second control link (L2), a first synchronization link (S1), a second synchronization link (S2), a controlled device, and a pressure sensor. Through the triple hardware redundancy architecture of double-controller redundancy hot backup, double control links and double synchronization links, the unified communication architecture, and the ring network channel composed of a coupler and a control link, data synchronization is realized, and the single point failure risk of the constant pressure water supply control system is completely eliminated. No matter single PLC failure, single control link interruption, or single or even two synchronization link interruptions, the system can automatically detect and quickly and seamlessly switch or maintain control, ensuring the continuous operation of the constant pressure water supply.

Description

A dual-link hot-standby redundant constant pressure water pump control system and its control method Technical Field

[0001] This invention relates to the technical field of constant pressure control systems for water pumps, specifically to a dual-link hot standby redundant constant pressure control system for water pumps and its control method. Background Technology

[0002] In the field of constant pressure water supply control in smart water management, the core objective of the control system is to maintain a constant pressure in the water supply network. This is typically achieved by a programmable logic controller (PLC) adjusting the speed of water pumps (especially variable frequency pumps). Current mainstream implementations rely on a single PLC controller architecture, which suffers from the following significant problems and drawbacks:

[0003] (1) High risk of single point of failure: The control center of the entire system relies on only a single PLC. Once the PLC experiences hardware failure (such as CPU failure, power failure, etc.), software crash, or interference, it will directly lead to the loss of control of the entire constant pressure water supply control system. At this time, the pipeline pressure may drop sharply (leading to water outage for users) or rise sharply (risk of pipe burst), with serious consequences. Although some high-end solutions use PLC hardware redundancy, its cost is significantly higher than that of standard PLC solutions, and it requires dedicated synchronization modules and redundant cables, resulting in high deployment complexity.

[0004] (2) Vulnerability of control link: The PLC and the key controlled equipment (such as couplers or frequency converters) usually rely on only a single physical control link (such as RS485 bus and Ethernet cable). If this link is interrupted due to physical damage (such as cable being cut), loose interface, electromagnetic interference, etc., the PLC will lose its ability to control the frequency converter, which will also lead to system failure.

[0005] (3) Low efficiency of master-slave switching and reliance on manual intervention: Some systems attempt to introduce a backup PLC, but the master-slave switching mechanism is often not perfect. Common problems include: (3.1) Switching detection relies on manual judgment or simple heartbeat timeout, resulting in slow response; (3.2) The switching process requires manual intervention for confirmation or operation; (3.3) The program status of the PLC is inconsistent with that of the master PLC after power-on, requiring reprogramming or complex configuration; (3.4) Long switching time, usually requiring several minutes, which cannot meet the high real-time requirements of water supply system for pressure stability. The long switching time will inevitably cause the pipeline pressure fluctuation to exceed the allowable range.

[0006] (4) Insufficient reliability of master-slave synchronization link: The master PLC and slave PLC need to synchronize status data in real time to achieve hot standby. Existing solutions usually rely on only a single synchronization link (such as an Ethernet cable). Once this link is interrupted, it will cause inconsistency between master and slave PLC data, which may lead to dual-master conflict (both PLCs try to control the device), or the standby PLC cannot effectively take over.

[0007] (5) Lack of collaborative processing mechanism for link interruption: When the control link of the master PLC is interrupted, but it is still running, or when the synchronization link between the master and slave PLCs is interrupted, the existing technology lacks an effective mechanism to allow the slave PLC to quickly and accurately take over control or maintain necessary data synchronization.

[0008] Therefore, there is an urgent need to provide a new solution to address the defects and shortcomings of the existing technologies. Summary of the Invention

[0009] To address the shortcomings and deficiencies in existing technologies, this invention provides a dual-link hot standby redundant constant pressure water pump control system and its control method.

[0010] The specific solution provided by this invention is as follows:

[0011] A dual-link hot-standby redundant constant pressure control system for water pumps, characterized in that: the system includes:

[0012] The main controller receives pipeline pressure data in real time, executes a preset control algorithm, calculates and outputs control commands;

[0013] The slave controller can switch to become the master controller when the master controller fails or is interrupted. It synchronizes the status data and control parameters of the master controller in real time, but does not output control commands.

[0014] A first control link connects the main controller and the controlled device, and the main controller can send corresponding control commands to the controlled device through the first control link;

[0015] The second control link connects the slave controller and the controlled device. After the slave controller is converted into the master controller, it can send corresponding control commands to the controlled device through the second control link.

[0016] The first synchronous link connects the master controller and the slave controller. The first synchronous link serves as the primary communication channel, and the master controller and the slave controller can transmit status data, control parameters, and heartbeat signals in real time through the first synchronous link.

[0017] The second synchronous link connects the master controller and the slave controller. The second synchronous link serves as a backup communication channel. The master controller and the slave controller can transmit status data, control parameters, and heartbeat signals in real time through the second synchronous link.

[0018] The controlled device is connected to both the main controller and the slave controller to perform corresponding control actions according to the received control commands.

[0019] A pressure sensor is installed inside the pipeline network to monitor the pipeline network pressure in real time and feed the monitored values ​​back to the current main controller in real time.

[0020] As a further preferred embodiment of the present invention, the controlled device includes at least a coupler, which is connected to the corresponding water pump after passing through an I / O module and a frequency converter.

[0021] As a further preferred embodiment of the present invention, the coupler can send the control commands output by the main controller to the frequency converter after passing through the corresponding I / O module, and the frequency converter can control the water pump accordingly through the control commands; it can also feed back the pipeline pressure monitored in real time by the pressure sensor to the current main controller; it can also receive the synchronization data packet of the main controller through the first control link and then transmit it to the slave controller through the second control link, and receive the synchronization data packet of the slave controller through the second control link and then transmit it to the main controller through the first control link.

[0022] As a further preferred embodiment of the present invention, the controlled device performs corresponding control actions according to the received control instructions, including start-stop control and speed adjustment of the corresponding water pump.

[0023] As a further preferred embodiment of the present invention, the system further includes a unified communication architecture, wherein the first control link and the second control link, as well as the first synchronization link and the second synchronization link, all use the unified communication architecture for data encapsulation and transmission.

[0024] Furthermore, the present invention also provides a control method for a dual-link hot-standby redundant constant pressure water pump control system, characterized by comprising the following steps:

[0025] S100: Power-on start-up dual controllers;

[0026] S200: The initial master-slave relationship between the two controllers is determined through a preset contention mechanism;

[0027] S300: The master controller sends an initialization data packet to the slave controller through the first synchronization link. The slave controller receives and stores the initialization data packet, thus completing the initialization synchronization.

[0028] S400: The main controller receives pipeline pressure data in real time, calculates the required control commands for the counter strain gauge based on the preset control algorithm, and sends the control commands to the counter strain gauge through the first control link;

[0029] S500: The master controller periodically sends synchronization data packets to the slave controller through the first synchronization link;

[0030] S600: Receives and stores synchronization data packets from the controller, updates its internal state image, and ensures that its data is completely consistent with the main controller, but does not send control commands to the corresponding frequency converter through the second control link;

[0031] S700: Take corresponding measures according to different fault types.

[0032] As a further preferred embodiment of the present invention, step S700 includes the following steps:

[0033] S711: The controller continuously monitors heartbeat signals and synchronization data packets from the master controller via the first and second synchronization links;

[0034] S712: If the controller does not receive any valid heartbeat signal or synchronization data packet within the preset timeout threshold, the main controller is determined to have failed.

[0035] S713: The controller immediately switches its state from "slave controller" to "master controller";

[0036] S714: The new master controller, after the switchover is complete, activates its control over the second control link and simultaneously shuts down the first control link;

[0037] S715: The new main controller, based on its stored latest synchronization data, sends control commands to the corresponding frequency converter through the second control link, seamlessly taking over the constant pressure water supply control task.

[0038] S716: The new main controller simultaneously triggers an alarm signal, indicating a main controller failure and a switching event.

[0039] As a further preferred embodiment of the present invention, step S700 includes the following steps:

[0040] S721: After sending a control command, the main controller detects the response of the first control link;

[0041] S722: If no valid response is received after sending control commands multiple times in a row or the link status detection fails, the first control link is determined to have been interrupted or failed.

[0042] S723: The master controller sends a link failure takeover command, current status data, and control parameters to the slave controller via the first or second synchronous link;

[0043] S724: After receiving the instruction from the controller, it switches its own state from "slave controller" to "master controller" within a preset time.

[0044] S725: The new master controller, after the switchover is complete, activates its control over the second control link and simultaneously shuts down the first control link;

[0045] S726: The new main controller, based on its stored latest synchronization data, sends control commands to the corresponding frequency converter through the second control link, seamlessly taking over the constant pressure water supply control task.

[0046] S727: After the original main controller detects that the first control link is interrupted and has been notified to take over from the controller, it sets its own status to "offline" or "pending repair" and stops sending control commands.

[0047] S728: The new master controller simultaneously triggers an alarm signal, indicating that the first control link has failed and a switching event has occurred.

[0048] As a further preferred embodiment of the present invention, step S700 includes the following steps:

[0049] S731: When the first synchronization link is interrupted: the system automatically switches to the second synchronization link for data synchronization, the master controller and slave controller continue to work normally, and triggers a fault alarm for the first synchronization link;

[0050] S732: When two synchronization links are interrupted simultaneously: both the master controller and the slave controller detect that the synchronization link with the other is completely interrupted;

[0051] S733: The master controller encapsulates the synchronization data packets that would normally be sent to the slave controller into a message with the slave controller as the destination address using the bus protocol;

[0052] S734: The main controller sends this synchronization data packet to the coupler via the first control link;

[0053] S735: When the coupler receives a synchronization data packet with the target address being the slave controller, it does not execute its control content, but instead forwards the synchronization data packet to the slave controller as is through the second control link connected to it.

[0054] S736: Data synchronization is achieved by receiving synchronization data packets from the master controller forwarded by the coupler from the controller via its second control link;

[0055] S737: Synchronization data packets that the slave controller needs to send to the master controller are transmitted to the master controller via the reverse path;

[0056] S738: Triggers an alarm signal, indicating a complete link failure alarm.

[0057] As a further preferred embodiment of the present invention, step S800 is also included, wherein step S800 includes:

[0058] S801: After repairing the previously faulty controller, reconnect it to the system and power it on;

[0059] S802: After starting the controller, it checks the network status. If it finds that there is a valid master controller, it automatically sends a join request signal to the current master controller.

[0060] S803: After receiving the request, the current master controller sends a complete control program image, current operating parameters and device status snapshot to the newly joined controller through an available synchronous link or a ring network channel composed of couplers and control links.

[0061] S804: The newly added controller receives and loads the above data, making its internal state completely synchronized with the current master controller;

[0062] S805: After synchronization is complete, the newly added controller automatically sets its own status to slave controller and backs up the master controller data in real time through the synchronization link;

[0063] S806: Triggers an alarm signal to notify the failed controller that it has recovered and rejoined the system.

[0064] Compared with existing technologies, the technical effects that this invention can achieve include:

[0065] 1) This invention provides a dual-link hot-standby redundant constant pressure water pump control system and its control method, improving system reliability: Through a triple hardware redundancy architecture of dual controller redundancy hot standby, dual control links, and dual synchronization links, combined with a unified communication architecture and a ring network channel composed of couplers and control links to achieve data synchronization, the risk of single-point failure in the constant pressure water supply control system is completely eliminated. Whether it is a single PLC failure, a single control link interruption, or even a single or two synchronization link interruptions, the system can automatically detect and quickly and seamlessly switch or maintain control, ensuring continuous operation of the constant pressure water supply.

[0066] 2) This invention provides a dual-link hot standby redundant constant pressure control system for water pumps and its control method. The fault switching time is greatly shortened and the switching process is fully automated. Based on accurate timeout detection and state transition, the switching time is controlled in milliseconds (typical value ≤50ms), which is much lower than the traditional manual switching (minutes) or simple backup system switching (seconds). This minimizes pipeline pressure fluctuations and meets the high stability requirements of the water supply system.

[0067] 3) This invention provides a dual-link hot-standby redundant constant pressure water pump control system and its control method. The communication link has strong fault tolerance: data packets in the link follow the VSOA format protocol, and the entire system can tolerate the interruption of any single control link; it can also tolerate the interruption of any single synchronization link. In extreme cases (simultaneous interruption of both synchronization links), a ring network channel is constructed using the controlled device (coupler) and the dual control links to maintain the synchronization of critical data. Through control switching and link management coordination logic, the risk of dual-master command conflicts is effectively avoided. This innovation provides a final guarantee for the stability of the constant pressure water supply control system.

[0068] 4) This invention provides a dual-link hot standby redundant constant pressure control system for water pumps and its control method, which improves maintenance convenience while reducing costs. This is reflected in two aspects: First, it eliminates the manual programming process. After the faulty controller is repaired and reconnected, it automatically synchronizes the complete program image and real-time status from the currently running main controller, eliminating the need for technicians to program on-site or manually configure parameters, greatly simplifying the maintenance process and shortening recovery time. Second, it reduces hardware redundancy costs. Compared with dedicated hardware redundancy systems, this invention can be implemented using standard controllers, achieving high reliability through software and communication protocol innovation, and significantly reducing costs.

[0069] 5) This invention provides a dual-link hot standby redundant constant pressure control system for water pumps and its control method, which has a high degree of intelligence: the entire fault detection, decision-making, switching and recovery process is fully automated, requiring no manual intervention, reducing the risk of human error, and improving the intelligence level and availability of the system.

[0070] 6) This invention provides a dual-link hot standby redundant constant pressure control system for water pumps and its control method, which has high engineering implementation value: it significantly shortens the downtime of the water supply system caused by equipment or link failures, improves the quality of water supply services, reduces operation and maintenance costs, and has significant engineering application value. Attached Figure Description

[0071] Figure 1 shows the logic structure diagram of the control system provided by the present invention.

[0072] Figure 2 shows a flowchart of the control method provided by the present invention. Detailed Implementation

[0073] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0074] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for 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. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0075] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0076] [First Embodiment]

[0077] As shown in Figure 1, the first embodiment of the present invention provides a dual-link hot standby redundant water pump constant pressure control system, the system comprising:

[0078] The main controller, PLC1, receives pipeline pressure data in real time, executes a preset control algorithm, calculates and outputs control commands. The preset control algorithm can be, for example, a PID numerical control algorithm, which adjusts system errors through proportional, integral, and derivative control methods to achieve precise control. Its controller parameters can be tuned through theoretical calculations or engineering experience. It features a simple structure, good stability, and convenient adjustment, and is widely used in industrial automation.

[0079] Slave controller PLC2 can switch to master controller PLC1 when the master controller fails or is interrupted. It synchronizes the status data and control parameters of the master controller in real time, but does not output control commands. Slave controller PLC2 acts as a hot standby machine for master controller PLC1, ready to take over control at any time when master controller PLC1 or its control link fails.

[0080] The first control link L1 connects the main controller and the controlled device. The main controller PLC1 can send corresponding control commands to the controlled device through the first control link L1.

[0081] The second control link L2 connects the slave controller and the controlled device. After the slave controller PLC2 is converted into the master controller PLC1, it can send corresponding control commands to the controlled device through the second control link L2. The first control link L1 and the second control link L2 use independent and physically isolated communication channels, such as the serial communication standard RS485 or Ethernet, to ensure that the interruption of a single control link does not affect the use of the other link.

[0082] The first synchronous link S1 connects the master controller PLC1 and the slave controller PLC2. The first synchronous link S1 serves as the primary communication channel, enabling the master controller PLC1 and the slave controller PLC2 to transmit status data, control parameters, and heartbeat signals in real time through the first synchronous link S1.

[0083] The second synchronous link S2 connects the master controller PLC1 and the slave controller PLC2. The second synchronous link S2 serves as a backup communication channel, enabling real-time transmission of status data, control parameters, and heartbeat signals between the master controller PLC1 and the slave controller PLC2. The first synchronous link S1 and the second synchronous link S2 can be physical communication channels such as Ethernet. The first synchronous link S1 and the second synchronous link S2 are also set as physically isolated communication channels to ensure that data synchronization can be maintained by switching to the backup link when a single synchronous link is interrupted.

[0084] The controlled device is connected to both the main controller and the slave controller to perform corresponding control actions based on the received control commands. In this embodiment, the controlled device includes at least a coupler, which is connected to the corresponding water pump after passing through an I / O module and a frequency converter. The corresponding control actions performed by the controlled device based on the received control commands include start-stop control and speed adjustment of the corresponding water pump. A pressure sensor is installed inside the pipeline network to monitor the pipeline network pressure in real time and feeds back the monitored values ​​to the current main controller in real time.

[0085] It is worth noting that in the water pump constant pressure control system network mentioned in this embodiment, multiple water pump pipelines are set up, and each water pump pipeline is equipped with a water pump. In addition, each water pump pipeline is also equipped with a corresponding I / O module, frequency converter and pressure sensor, so as to detect the real-time pipeline network pressure of each water pump pipeline, and at the same time, different control commands can be received through the frequency converter to adjust the speed of the water pump in the current water pump pipeline accordingly.

[0086] In this embodiment, the coupler can send the control commands output by the main controller to the frequency converter after passing through the corresponding I / O module. The frequency converter then controls the water pump accordingly using the control commands. It can also feed back the pipeline pressure monitored in real time by the pressure sensor to the current main controller. Furthermore, it can receive synchronization data packets from the main controller via the first control link and transmit them to the slave controller via the second control link, and vice versa. In extreme cases (when both synchronization links are interrupted simultaneously), a ring network channel is constructed using the coupler in the controlled device and the dual control links L1 and L2 (forming a data synchronization path: main controller PLC1 → first control link L1 → coupler → second control link L2 → slave controller PLC2 or slave controller PLC2 → second control link L2 → coupler → first control link L1 → main controller PLC1), maintaining critical data synchronization. Through control switching and link management coordination logic, the risk of dual-master command conflicts is effectively avoided.

[0087] Based on this, the control system mentioned in this embodiment also adopts a unified communication architecture. The first control link L1 and the second control link L2, as well as the first synchronization link S1 and the second synchronization link S2, all adopt a unified communication architecture for data encapsulation and transmission. This unified communication architecture preferably adopts the communication architecture of the VSOA (Virtual Service Oriented Architecture) soft bus communication protocol to facilitate the unified encapsulation and transmission of data.

[0088] Through a triple hardware redundancy architecture—dual controller redundancy hot standby, dual control links, and dual synchronization links—coupled with a unified communication architecture and a ring network channel composed of couplers and control links to achieve data synchronization, the risk of single-point failure in the constant pressure water supply control system is completely eliminated. Whether it is a single PLC failure, a single control link interruption, or even a single or two synchronization link interruptions, the system can automatically detect and quickly and seamlessly switch or maintain control, ensuring continuous operation of the constant pressure water supply.

[0089] The data packets in the link follow the VSOA format protocol, and the entire system can tolerate the interruption of any single control link and any single synchronization link. In extreme cases (simultaneous interruption of both synchronization links), a ring network channel is constructed using the controlled device (coupler) and the two control links to maintain the synchronization of critical data. Through control switching and link management coordination logic, the risk of dual-master command conflicts is effectively avoided. This innovation provides a final guarantee for the stability of the constant pressure water supply control system.

[0090] Each device in the system (such as controllers, couplers, frequency converters, etc.) exists in the form of resources and is accessed through standardized URLs to achieve structured and efficient interaction between control commands and status data, providing underlying communication guarantees for redundancy switching.

[0091] [Second Embodiment]

[0092] Figure 2 shows a control method for a dual-link hot standby redundant water pump constant pressure control system in the first embodiment provided by the second embodiment of the present invention, including the following steps:

[0093] First, perform system initialization and determine the master-slave relationship, including the following steps:

[0094] S100: Power-on start-up dual controllers;

[0095] S200: The initial master-slave relationship between the two controllers is determined by a preset competition mechanism. The preset competition mechanism can be set according to actual needs. For example, the master controller PLC1 can be established by comparing the unique ID numbers of the devices and giving priority to the smaller one.

[0096] S300: The main controller PLC1 sends an initialization data packet to the slave controller PLC2 through the first synchronization link S1. The slave controller PLC2 receives and stores the initialization data packet, completing the initialization synchronization. The initialization data packet includes at least the current flow rate, constant pressure setpoint, PID control parameters, and equipment status flags.

[0097] The normal constant pressure control process includes the following steps:

[0098] S400: The main controller PLC1 receives pipeline pressure data in real time, calculates the required control commands for the counter strain gauge based on the preset control algorithm, and sends the control commands to the counter strain gauge through the first control link L1.

[0099] S500: The main controller PLC1 periodically (e.g., every 50ms) sends a synchronization data packet to the slave controller PLC2 through the first synchronization link S1; the synchronization data packet in this embodiment includes at least the real-time flow value, pressure value, calculated frequency command value, main controller status flag, timestamp, and information such as data integrity for verification.

[0100] S600: Receives and stores synchronization data packets from controller PLC2, updates its internal state mirror, and ensures that its data is completely consistent with the main controller PLC1, but does not send control commands to the corresponding frequency converter through the second control link L2.

[0101] S700: Implement corresponding handling measures based on different fault types. This embodiment mainly addresses fault types such as main controller failure, first control link L1 interruption failure, and synchronization link interruption.

[0102] For the fault type of main controller failure (e.g., main controller PLC1 crashing or freezing), step S700 in this embodiment includes the following steps:

[0103] S711: The slave controller PLC2 continuously monitors the heartbeat signal and synchronization data packets from the master controller PLC1 through the first synchronization link S1 and the second synchronization link S2;

[0104] S712: If the controller PLC2 does not receive any valid heartbeat signal or synchronization data packet within the preset timeout threshold (e.g., 50ms) (i.e., both the first synchronization link S1 and the second synchronization link S2 are detected to be faulty), then the main controller PLC1 is determined to have failed.

[0105] S713: The PLC2 controller immediately switches its status from "slave controller" to "master controller";

[0106] S714: After the switchover is complete, the new master controller PLC1 activates its control over the second control link L2, and at the same time shuts down the first control link L1;

[0107] S715: The new main controller PLC1, based on its stored latest synchronous data (such as flow rate, pressure value, PID status, etc.), sends control commands to the corresponding frequency converter through the second control link L2, seamlessly taking over the constant pressure water supply control task.

[0108] S716: The new main controller PLC1 simultaneously triggers an alarm signal, indicating that a fault or switching event has occurred in the main controller PLC1. For example, corresponding prompt information can be sent to the SCADA system or the mobile phone of maintenance personnel via RS485 or Ethernet. SCADA (Supervisory Control and Data Acquisition) is a computer-based industrial automation control system that is widely used in fields such as power, petroleum, chemical, and transportation to achieve real-time monitoring, data acquisition, and control of the production process.

[0109] For the fault type of interruption failure of the first control link L1 (with the main controller PLC1 functioning normally), namely step S700 in this embodiment, the following steps are included:

[0110] S721: After sending control commands, the main controller PLC1 detects the response of the first control link L1 (e.g., the coupler's response signal).

[0111] S722: If no valid response is received or the link status detection fails after sending control commands multiple times (e.g., 3 times), it is determined that the first control link L1 has been interrupted and failed.

[0112] S723: The main controller PLC1 sends a link failure takeover command, current status data, and control parameters to the slave controller PLC2 through the first synchronous link S1 (if the first synchronous link S1 is normal) or the second synchronous link S2 (if the first synchronous link S1 is interrupted but the second synchronous link S2 is normal);

[0113] S724: After receiving this instruction from the PLC2 controller, it will switch its own status from "slave controller" to "master controller" within a preset time (e.g., ≤50ms);

[0114] S725: After the switchover is complete, the new master controller PLC1 activates its control over the second control link L2, and at the same time shuts down the first control link L1;

[0115] S726: The new main controller PLC1, based on its stored latest synchronization data, sends control commands to the corresponding frequency converter through the second control link L2, seamlessly taking over the constant pressure water supply control task.

[0116] S727: After the original master controller PLC1 detects that the first control link L1 is interrupted and has notified the slave controller PLC2 to take over, it sets its own status to "offline" or "pending repair" and stops sending control commands.

[0117] S728: The new main controller PLC1 simultaneously triggers an alarm signal, indicating that the first control link L1 has failed due to an interruption and a switching event has occurred.

[0118] Regarding the fault type of synchronous link interruption, step S700 mentioned in this embodiment includes the following steps:

[0119] Regarding the interruption of the first synchronization link S1: S731: When the first synchronization link S1 is interrupted: the system automatically switches to the second synchronization link S2 for data synchronization, the master controller PLC1 and the slave controller PLC2 continue to work normally, and trigger the first synchronization link S1 fault alarm.

[0120] For simultaneous interruption of two synchronization links: S732: When two synchronization links are interrupted simultaneously: both the master controller PLC1 and the slave controller PLC2 detect that the synchronization link with the other is completely interrupted.

[0121] S733: The master controller PLC1 encapsulates the synchronization data packets (including at least real-time flow value, pressure value, frequency command, status flag, etc.) that originally needed to be sent to the slave controller PLC2 into a message with the target address of the slave controller PLC2 using a bus protocol (e.g., URL addressing format).

[0122] S734: The main controller PLC1 sends this synchronization data packet to the coupler through the first control link L1;

[0123] S735: When the coupler receives a synchronization data packet with the target address being the slave controller PLC2, it does not execute its control content. Instead, it forwards the synchronization data packet to the slave controller PLC2 as is through the second control link L2 connected to it.

[0124] S736: The slave controller PLC2 receives the synchronization data packet from the master controller PLC1 forwarded by the coupler through its second control link L2, thereby realizing data synchronization; at this time, the data synchronization path is: master controller PLC1 → first control link L1 → coupler → second control link L2 → slave controller PLC2;

[0125] S737: If the synchronization data packet that the slave controller PLC2 needs to send to the master controller PLC1 is transmitted to the master controller PLC1 through the reverse path; at this time, the data synchronization path is: slave controller PLC2 → second control link L2 → coupler → first control link L1 → master controller PLC1;

[0126] S738: Triggers an alarm signal, indicating a complete link failure alarm.

[0127] By utilizing the coupler in the controlled device as a data relay node, and combining it with control links L1 and L2 to form a ring network redundancy channel, even in the extreme case where both synchronization links S1 and S2 fail, the minimum critical data synchronization between the master controller and the slave controller is still maintained, providing a data foundation for possible control handover.

[0128] It also includes step S800, a fault recovery and self-healing mechanism, which includes:

[0129] S801: After repairing the previously faulty controller, reconnect it to the system and power it on;

[0130] S802: After starting the controller, it checks the network status. If it finds that there is a valid master controller, it automatically sends a join request signal to the current master controller.

[0131] S803: After receiving the request, the current master controller sends a complete control program image, current operating parameters (PID parameters and other preset values, etc.) and a snapshot of the device status to the newly joined controller through an available synchronous link or a ring network channel composed of couplers and control links.

[0132] S804: The newly added controller receives and loads the above data, making its internal state completely synchronized with the current master controller;

[0133] S805: After synchronization is complete, the newly added controller automatically sets its own status to slave controller and backs up the master controller data in real time through the synchronization link;

[0134] S806: Triggers an alarm signal to notify the failed controller that it has recovered and rejoined the system.

[0135] The entire process eliminates the need for manual programming. After the faulty controller is repaired and reconnected, it automatically synchronizes the complete program image and real-time status from the currently running main controller. This eliminates the need for technicians to program on-site or manually configure parameters, greatly simplifying the maintenance process and shortening recovery time.

[0136] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A dual-link hot standby redundant constant pressure control system for water pumps, characterized in that: The system includes: a main controller (PLC1), which receives pipeline pressure data in real time, executes a preset control algorithm, calculates and outputs control commands; a slave controller (PLC2), which can switch to the main controller (PLC1) when the main controller fails or is interrupted, synchronizing the main controller's status data and control parameters in real time, but not outputting control commands; and a first control link (L1), which connects the main controller and the controlled device, allowing the main controller (PLC1) to send commands to the controlled device via the first control link (L1). The system includes: a corresponding control command; a second control link (L2) connecting the slave controller (PLC2) and the controlled device; and a first synchronization link (S1) connecting the master controller (PLC1) and the slave controller (PLC2). The first synchronization link (S1) serves as the primary communication channel, enabling communication between the master controller (PLC1) and the slave controller (PLC2) via the first synchronization link. The system includes: a first synchronous link (S1) for real-time transmission of status data, control parameters, and heartbeat signals; a second synchronous link (S2) connecting the master controller (PLC1) and the slave controller (PLC2), serving as a backup communication channel; a controlled device connected to both the master and slave controllers to perform corresponding control actions based on received control commands; and a pressure sensor. The pressure sensor is installed inside the pipeline network to monitor the pipeline network pressure in real time and feeds back the monitored value to the current main controller in real time. The controlled device includes at least a coupler, which is connected to the corresponding water pump after passing through the I / O module and the frequency converter. The coupler can send the control commands output by the main controller to the frequency converter after passing through the corresponding I / O module. It can also receive the synchronization data packets of the main controller through the first control link and then transmit them to the slave controller through the second control link, and receive the synchronization data packets of the slave controller through the second control link and then transmit them to the main controller through the first control link.

2. The dual-link hot standby redundant water pump constant pressure control system according to claim 1, characterized in that: The frequency converter controls the water pump according to the control commands; the coupler can also feed back the pipeline pressure monitored in real time by the pressure sensor to the current main controller.

3. The dual-link hot standby redundant water pump constant pressure control system according to claim 1, characterized in that: The controlled equipment performs corresponding control actions according to the received control commands, including start / stop control and speed adjustment of the corresponding water pump.

4. The dual-link hot standby redundant water pump constant pressure control system according to claim 1, characterized in that: The system also includes a unified communication architecture, in which the first control link (L1) and the second control link (L2), as well as the first synchronization link (S1) and the second synchronization link (S2), all use the unified communication architecture for data encapsulation and transmission.

5. The control method for a dual-link hot standby redundant constant pressure water pump control system according to any one of claims 1-4, characterized in that: The process includes the following steps: S100: Power on and start the dual controllers; S200: Determine the initial master-slave relationship of the dual controllers through a preset competition mechanism; S300: The master controller (PLC1) sends an initialization data packet to the slave controller (PLC2) through the first synchronization link (S1), and the slave controller (PLC2) receives and stores the initialization data packet, completing the initialization synchronization; S400: The master controller (PLC1) receives pipeline pressure data in real time and calculates the required control commands for the counter frequency converter based on a preset control algorithm, and sends the control commands to the counter frequency converter through the first control link (L1); S500: The master controller (PLC1) periodically sends synchronization data packets to the slave controller (PLC2) through the first synchronization link (S1); S600: The slave controller (PLC2) receives and stores the synchronization data packets, updates its internal state mirror, and ensures that its data is completely consistent with that of the master controller (PLC1), but does not send control commands to the counter frequency converter through the second control link (L2); S700: Take corresponding measures according to different fault types.

6. The control method for a dual-link hot standby redundant constant pressure water pump control system according to claim 5, characterized in that: In step S700 The process includes the following steps: S711: The slave controller (PLC2) continuously monitors the heartbeat signal and synchronization data packets from the master controller (PLC1) through the first synchronization link (S1) and the second synchronization link (S2); S712: If the slave controller (PLC2) does not receive any valid heartbeat signal or synchronization data packets within a preset timeout threshold, it determines that the master controller (PLC1) has failed; S713: The slave controller (PLC2) immediately switches its status from "slave controller" to "master controller"; S714: The new master controller, after the switch is completed, activates its control over the second control link (L2) and simultaneously closes the first control link (L1); S715: Based on its latest stored synchronization data, the new master controller sends control commands to the corresponding strain gauge through the second control link (L2), seamlessly taking over the constant pressure water supply control task; S716: The new master controller simultaneously triggers an alarm signal, indicating that the master controller (PLC1) has failed and the switchover event has occurred.

7. The control method for a dual-link hot standby redundant constant pressure water pump control system according to claim 5, characterized in that: Step S700 includes the following steps: S721: After sending a control command, the master controller (PLC1) detects the response of the first control link (L1); S722: If no valid response is received after sending multiple control commands consecutively, or if the link status detection fails, the first control link (L1) is determined to have failed; S723: The master controller (PLC1) sends a link fault takeover command, current status data, and control parameters to the slave controller (PLC2) through the first synchronous link (S1) or the second synchronous link (S2); S724: After receiving the command, the slave controller (PLC2) switches its status from "slave controller" to "master controller" within a preset time; S725: The new master controller, after the switch is complete, activates its control over the second control link (L2). S726: The new main controller, based on its latest stored synchronization data, sends control commands to the corresponding frequency converter through the second control link (L2), seamlessly taking over the constant pressure water supply control task; S727: After the original main controller (PLC1) detects the interruption of the first control link (L1) and has notified the slave controller (PLC2) to take over, it sets its own status to "offline" or "pending repair" and stops sending control commands; S728: The new main controller simultaneously triggers an alarm signal, indicating that the first control link (L1) has failed and a switching event has occurred.

8. The control method for a dual-link hot standby redundant constant pressure water pump control system according to claim 5, characterized in that: In step S700 The process includes the following steps: S731: When the first synchronization link (S1) is interrupted: the system automatically switches to the second synchronization link (S2) for data synchronization. The master controller (PLC1) and the slave controller (PLC2) continue to operate normally, and a fault alarm is triggered for the first synchronization link (S1); S732: When both synchronization links are interrupted simultaneously: both the master controller (PLC1) and the slave controller (PLC2) detect that the synchronization link with each other is completely interrupted; S733: The master controller (PLC1) encapsulates the synchronization data packet that was originally to be sent to the slave controller (PLC2) into a message with the destination address of the slave controller (PLC2) using the bus protocol; S734: The master controller (PLC1) transmits the data via the first control link (L1). S735: The coupler receives this synchronization data packet destined for the slave controller (PLC2), but does not execute its control content. Instead, it forwards the synchronization data packet to the slave controller (PLC2) as is through the second control link (L2) connected to it. S736: The slave controller (PLC2) receives the synchronization data packet forwarded by the coupler from the master controller (PLC1) through its second control link (L2), thereby achieving data synchronization. S737: If the slave controller (PLC2) needs to send a synchronization data packet to the master controller (PLC1), it transmits it to the master controller (PLC1) through the reverse path. S738: An alarm signal is triggered, indicating a link complete interruption failure alarm.

9. The control method for a dual-link hot standby redundant constant pressure water pump control system according to claim 5, characterized in that: The system also includes step S800, which comprises: S801: After repairing the previously faulty controller, reconnect it to the system and power it on; S802: After starting the controller, check the network status. If a valid master controller is found, automatically send a join request signal to the current master controller; S803: After receiving the request, the current master controller sends a complete control program image, current operating parameters, and device status snapshot to the newly joined controller through an available synchronization link or a ring network channel composed of couplers and control links; S804: The newly joined controller receives and loads the above data, making its internal state completely synchronized with the current master controller; S805: After synchronization is completed, the newly joined controller automatically sets its own state to slave controller and backs up the master controller data in real time through the synchronization link; S806: Trigger an alarm signal to notify that the failed controller has recovered and rejoined the system.

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