System for automatically adjusting and controlling water level and flow of trunk canal gate

Abstract

The invention relates to the technical field of electrical automation, and discloses an automatic adjustment and control system for water level and flow of a trunk canal gate, which comprises a throw-in type liquid level meter, a frequency converter, an opening load instrument, a PLC (Programmable Logic Controller) and a touch screen, and the automatic adjustment and control of the system comprises the following steps: S1, multi-source signal acquisition, S2, control mode decision, S3, modeling control execution, and S4, modeling control execution. And S4, performing real-time data interaction and protection. Under the condition that the throw-in type liquid level transmitter has no fault, the system can automatically adjust the opening degree of the gate according to the water level of the reservoir as long as the upper computer gives the flow value requirement, operation and maintenance personnel can control the gate to ascend or descend only by remotely setting the flow in the central control room even if the throw-in type liquid level transmitter has the fault, and the operation and maintenance efficiency is greatly improved. And on-site actual operation is not needed, so that the manpower consumption is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of electrical automation technology, specifically to an automatic adjustment and control system for water level and flow rate of a canal gate. Background Technology

[0002] The existing main canal gates of the hydropower plant primarily serve to provide downstream water for production, domestic use, and agricultural irrigation. At a given reservoir water level, to simultaneously meet the water demand of both the hydropower station and downstream users, the main canal gate control system needs to frequently adjust its opening to control the flow and achieve water conservation. The existing main canal gate control system requires on-site personnel to manually operate the gates based on water level changes, which is inconvenient, time-consuming, and labor-intensive, and also detrimental to water conservation.

[0003] In addition, the existing gate hoists for the main canal can only be operated locally and do not have the capability for remote operation, automatic control adjustment and monitoring. They cannot monitor the opening degree and flow of the main canal gates in real time or operate them remotely, which does not meet the requirements of hydropower plants for fewer staff on duty, unattended operation and energy saving. Therefore, it is necessary and feasible to upgrade them.

[0004] Based on the above problems, we decided to design a gate control system with more comprehensive protection functions and a higher degree of automation to solve these problems. Summary of the Invention

[0005] The purpose of this invention is to provide an automatic adjustment and control system for water level and flow rate of gates in dry canals, so as to solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: This invention relates to an automatic adjustment and control system for water level and flow rate of a canal gate. The system includes a submersible level gauge, a frequency converter, an opening load cell, a PLC controller, and a touch screen. The automatic adjustment and control of the system includes the following steps: Step S1, Multi-source signal acquisition, includes the following process: S1-1. Real-time acquisition of reservoir water level using an immersion level gauge and conversion into a 4-20mA electrical signal; S1-2. The gate opening value and weight data are simultaneously acquired using an opening load cell; S1-3. Receive the target flow command issued by the central control room monitoring system; Step S2, Control Mode Decision, includes the following process: S2-1. Perform quality judgment on the water level signal. If the signal is valid, trigger the automatic control mode. If the signal fails, trigger the remote control mode and send a fault alarm. S2-2. When responding to local operation instructions, local mode is triggered; Step S3, Execution of Modular Control, including automatic control mode, remote control mode, and local mode, specifically involves the following process: S3-1. Automatic control mode; S3-2. Remote control mode: Parses operation commands issued by the monitoring system and executes gate lifting, lowering, stopping, or emergency stop. S3-3. Local mode; Step S4, Real-time Data Interaction and Protection, includes the following processes: S4-1. Upload gate opening, load, water level, control status and alarm data to the monitoring system; S4-2. When the load cell detects an abnormal weight, it triggers the emergency stop protection and uploads an alarm.

[0007] Furthermore, the automatic control mode described in step S3 includes the following process; a. Based on the target flow rate and the current water level, calculate the target opening by calling the pre-stored opening-flow mathematical model in the PLC; b. Perform closed-loop control of the opening degree. If the target opening degree is greater than the current opening degree, drive the gate to rise until the two are the same. If the target opening degree is less than the current opening degree, drive the gate to fall until the two are the same. c. When the real-time opening degree is greater than or equal to the preset limit threshold, the lifting action is forcibly terminated.

[0008] Furthermore, the in-situ mode described in step S3 is the following process: a. Directly control the gate in response to start / stop commands from local buttons; b. Adjust the inverter output frequency via the touchscreen to change the operating speed.

[0009] Furthermore, the aperture-flow mathematical model is constructed as follows: a1. Measure the flow rate data at N typical water level values. At each water level value, the gate is opened at an arithmetic interval. After the gate stabilizes at each opening point, the corresponding flow rate is collected by an ultrasonic flow meter. a2. Construct an independent mapping function for each water level segment, and use cubic spline interpolation to generate a continuous curve of opening degree-flow rate. Store this curve in the PLC as a two-dimensional lookup table, with the row index being the normalized water level value and the column index being the opening degree value. a3. Online model correction mechanism: When the deviation between measured flow and predicted flow continues, the curve coefficients are self-learned, and the parameters are continuously optimized by updating the mapping relationship.

[0010] Furthermore, the construction function of the opening-flow mathematical model Including the following: a1. At five characteristic water points, the flow rate was adjusted in increments of ΔL = 10 cm, and the stable flow rate Q was recorded using an ultrasonic flow meter. Among them, 5 characteristic water points are To form a dataset ; a2. For each water level segment, construct a continuous function using cubic spline interpolation. Inverse function generation ; Among them, the water level section is extracted as ; The parameterized matrix stored in PLC a3. is:

[0011] Where row index i corresponds to the normalized water level, column index j corresponds to the openness, and element This represents the flow rate value.

[0012] Furthermore, the quality judgment described in step S2 specifically includes signal validity verification and fault diagnosis and handling, which are divided into the following processes: a1. Signal validity verification involves range detection and fluctuation detection. If the current value is <3.8mA or >20.5mA for 500ms, it is determined to be out of range. Calculate the standard deviation of 10 sampling points within the sliding window. ,like Then the fluctuation is determined to be abnormal; a2. Fault diagnosis and handling: A retry mechanism is initiated for abnormal signals. Three consecutive data collections are performed at 100ms intervals. If the abnormality persists after the retry, it is marked as a "hard fault" and the automatic mode is locked. If the retry is successful, it is marked as a "soft fault" but the automatic mode is maintained.

[0013] Furthermore, the automatic control mode described in step S3 also includes a dual-loop structure for the opening closed-loop control and variable speed control for gate lifting / lowering, specifically as follows: a1. The outer loop is the position loop. The PID controller inputs the opening deviation and outputs the speed command, which consists of a proportional term, an integral term s, and a derivative term s. a2. The inner loop is the speed loop. The PI controller inputs the speed deviation and outputs the motor torque command. The torque limit is 75% to 85% of the motor's rated torque. a3. Speed ​​control for gate lifting / lowering: when the gate is at 100% of rated speed, when the gate is at 60% of rated speed, when the gate is at 30% of rated speed.

[0014] Furthermore, the speed control in the automatic control mode satisfies the following parameters: Position loop PID parameters:

[0015] Velocity feedforward compensation: in, .

[0016] Furthermore, the real-time data interaction and protection described in step S4 also includes the linkage of a data interaction protocol stack and a multi-level protection mechanism, as follows: a. The data interaction protocol stack consists of a physical layer, a transport layer, and an application layer. The physical layer adopts the IEEE 802.3 Ethernet standard, the transport layer encapsulates real-time data packets based on the UDP protocol, and the application layer defines a custom binary frame structure. b. The multi-level protection mechanism is divided into primary protection, secondary protection and manual protection. Primary protection issues an early warning and reduces the speed to 50% when the load is greater than 105% of the rated value. Secondary protection triggers a 0.2s emergency stop when the load is greater than 115% of the rated value or the opening change rate is greater than 8cm / s². Manual protection is to manually confirm the protection reset on site.

[0017] Furthermore, the aforementioned multi-level protection mechanism linkage specifically includes: a1. Primary protection ( (This includes reducing the speed to 50% and uploading a warning code 0xF1.) a2. Secondary protection ( or (This refers to the hardware emergency stop circuit, which has a response time of ≤100ms.) a3. Protection reset must be met simultaneously: press the local confirmation button + load recovery to normal for 5 seconds.

[0018] The present invention has the following beneficial effects: (1) When the submersible level transmitter is fault-free, the system will automatically adjust the gate opening according to the reservoir water level as long as the host computer gives the required flow rate. Even if the submersible level transmitter is faulty, the maintenance personnel can control the gate to rise or fall by remotely setting the flow rate in the central control room without having to go to the site for actual operation, thereby reducing manpower consumption and improving production efficiency.

[0019] (2) The present invention communicates with the monitoring system (including information such as water level, current gate opening, gate weight, level gauge failure, frequency converter failure, power supply failure, PLC failure, etc.), and the host computer can monitor the working status of the gate control system in real time to achieve real-time monitoring.

[0020] (3) The frequency converter control of the wound motor starting method of the present invention is more reliable than the previous rotor series resistance starting method, avoiding the problem of frequent replacement of AC contactors, reducing the amount of equipment maintenance, and the opening limit function can be set through the touch screen to avoid the problem of automatic opening of the gate due to the previous gate malfunction.

[0021] (4) The present invention imports the flow rate opening degree and reservoir water level curve through the program, so that the gate can be automatically adjusted. According to the given flow rate, the gate control detection curve automatically controls the gate at a certain opening degree to ensure that the flow rate is constant.

[0022] (5) The present invention sets the opening limit through the program. When the upper limit of the opening is reached, the PLC activates the relay to automatically lift the K6 contact to disconnect, thereby cutting off the control circuit lockout. When the lower limit of the opening is reached, the PLC activates the relay to automatically lift the K7 contact to disconnect, thereby cutting off the control circuit lockout. This prevents the gate from running automatically due to human error or contact adhesion.

[0023] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a flow rate curve corresponding to the reservoir water level of this invention; Figure 2 This is the control loop diagram for the present invention. Detailed Implementation

[0026] 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.

[0027] Please see Figures 1-2 As shown, this invention relates to an automatic adjustment and control system for water level and flow rate of a main canal gate. The system includes a submersible level gauge, a frequency converter, an opening and load cell, a PLC controller, and a touch screen. In this embodiment, the submersible level gauge is installed upstream of the reservoir to measure the reservoir water level and participate in the logic control of the main canal gate. The frequency converter is installed in the control cabinet to control the forward and reverse rotation of the motor, thereby controlling the opening, closing, and speed of the gate. The opening and load cell is installed in the control cabinet to measure the current gate opening and weight, and also for protection control. The touch screen is installed in the control cabinet to set various parameters and display gate opening, load, and alarm data.

[0028] Preferably, the PLC controller is installed inside the control cabinet to collect external switch and analog signals. After internal program processing, it outputs corresponding gate start / stop signals and protection signals. It communicates with the central control room monitoring system via network port, transmitting current gate opening, load, reservoir water level, control status, and alarm status to the monitoring system. The automatic adjustment control of this system includes the following steps: Step S1, Multi-source signal acquisition, includes the following process: S1-1. Real-time acquisition of reservoir water level using an immersion level gauge and conversion into a 4-20mA electrical signal; S1-2. The gate opening value and weight data are simultaneously acquired using an opening load cell; S1-3. Receive the target flow command issued by the central control room monitoring system; Step S2, Control Mode Decision, includes the following process: S2-1. Perform quality judgment on the water level signal. If the signal is valid, trigger the automatic control mode. If the signal fails, trigger the remote control mode and send a fault alarm. In this embodiment, the quality judgment specifically includes signal validity verification and fault diagnosis and handling, which are divided into the following processes: a1. Signal validity verification involves range detection and fluctuation detection. If the current value is <3.8mA or >20.5mA for 500ms, it is determined to be out of range. Calculate the standard deviation of 10 sampling points within the sliding window. ,like Then the fluctuation is determined to be abnormal; a2. Fault diagnosis and handling: A retry mechanism is initiated for abnormal signals. Three consecutive data collections are performed at 100ms intervals. If the abnormality persists after the retry, it is marked as a "hard fault" and the automatic mode is locked. If the retry is successful, it is marked as a "soft fault" but the automatic mode is maintained.

[0029] S2-2. When responding to local operation instructions, local mode is triggered; Step S3, Execution of Modular Control, including automatic control mode, remote control mode, and local mode, specifically involves the following process: S3-1. Automatic control mode, including the following processes; a. Based on the target flow rate and the current water level, calculate the target opening degree using the pre-stored opening degree-flow rate mathematical model in the PLC. The target opening degree is... ; b. Perform closed-loop control of the opening degree. If the target opening degree is greater than the current opening degree, drive the gate to rise until the two are equal. If the target opening degree is less than the current opening degree, drive the gate to fall until the two are equal. The current opening degree value is... ; c. When the real-time opening degree is greater than or equal to the preset limit threshold, the lifting action is forcibly terminated and the motor output is locked. The preset limit threshold is... .

[0030] Preferably, in remote control mode, the PLC controller collects the 4-20mA signal from the reservoir's submersible level gauge and performs a quality judgment on this signal. If a level signal fault is detected, the PLC control system program locks the automatic control process, jumps to the remote control mode, and sends a level transmitter fault signal to the monitoring system. At this time, the system receives command signals from the monitoring system to control the gate's raising, lowering, stopping, and emergency stop, thereby avoiding maintenance personnel having to operate the gate on-site, ensuring safe equipment operation, and reducing manpower consumption.

[0031] In addition, when maintenance or on-site operation is required, switch to on-site mode to operate multiple gates via on-site lift, lower, and stop buttons. At the same time, the lifting speed can be changed by changing the motor frequency via the touch screen.

[0032] S3-2. Remote control mode: Parses operation commands issued by the monitoring system and executes gate lifting, lowering, stopping, or emergency stop. S3-3. Local mode, which consists of the following process: a. Directly control the gate in response to start / stop commands from local buttons; b. Adjust the inverter output frequency via the touchscreen to change the operating speed; Step S4, Real-time Data Interaction and Protection, includes the following processes: S4-1. Upload gate opening, load, water level, control status and alarm data to the monitoring system; S4-2. When the load cell detects an abnormal weight, it triggers the emergency stop protection and uploads an alarm.

[0033] In this S4 step, gate opening, load, water level, control status and alarm data are uploaded to the monitoring system via Ethernet. The data update cycle is ≤200ms. In addition, when the opening load cell detects that the weight exceeds the rated value by 115%, the hardware emergency stop circuit is triggered and alarm code 0xE2 is uploaded.

[0034] Preferably, the frequency converter-controlled wound motor starting method is more reliable than the previous rotor series resistance starting method, avoids the problem of frequent replacement of AC contactors, reduces equipment maintenance, and allows the opening limit function to be set through the touch screen, avoiding problems such as automatic gate opening due to gate malfunctions.

[0035] In this embodiment, the aperture-flow mathematical model is constructed as follows: a1. At N typical water level values The measured flow rate data is given below, with each water level value set at an arithmetic interval. Open the gate, At each opening point L j After stabilization, the corresponding flow rate Q is collected using an ultrasonic flow meter. j ; a2. For each water level segment An independent mapping function is constructed, and a continuous curve of opening degree-flow rate is generated using cubic spline interpolation. This curve is stored in the PLC as a two-dimensional lookup table, with the row index being the normalized water level value and the column index being the opening degree value. a3. Online model correction mechanism: when the deviation between measured and predicted flow continues... At that time, the curve coefficient self-learning is triggered, according to... Update the mapping relationship. Parameters optimized for scrolling.

[0036] Among them, the construction function of the opening-flow mathematical model in the above embodiments Including the following: a1. At five characteristic water points, the flow rate was adjusted in increments of ΔL = 10 cm, and the stable flow rate Q was recorded using an ultrasonic flow meter. Among them, 5 characteristic water points are To form a dataset Specifically

[0037] a2. For each water level segment, construct a continuous function using cubic spline interpolation. Inverse function generation ; Among them, the water level section is extracted as ; The parameterized matrix stored in PLC a3. is:

[0038] Where row index i corresponds to the normalized water level, column index j corresponds to the openness, and element This represents the flow rate value.

[0039] In this embodiment, the automatic control mode also includes a dual-loop structure for the opening closed-loop control and variable speed control for gate lifting / lowering, specifically as follows: a1. The outer loop is the position loop, and the PID controller input opening deviation. Output speed command proportional term Integral term s, differential term s; a2. The inner loop is the speed loop, and the PI controller inputs the speed deviation. It outputs motor torque commands, with the torque limit set at 75% to 85% of the motor's rated torque. a3. Speed ​​control for gate lifting / lowering, when When operating at 100% of rated speed, At that time, it runs at 60% of the rated speed. At that time, it operates at 30% of the rated speed.

[0040] The speed control in automatic control mode satisfies the following parameters: Position loop PID parameters:

[0041] Velocity feedforward compensation: in, .

[0042] Preferably, in automatic control mode, the PLC controller acquires the 4-20mA signal from the reservoir's submersible level gauge and performs a quality judgment on this signal. If the water level signal is normal, the PLC control system program jumps to the automatic control process lockout remote control mode process and then, based on the required flow rate value transmitted from the monitoring system communication, and according to the water level, opening degree, and flow rate curve (… Figure 1 The PLC's internal program calculates the required gate opening and compares it with the current gate opening. If the required opening is greater than the current opening, the system controls the gate to rise until the gate opening equals the required opening, at which point the gate stops rising. (To prevent the gate opening from becoming too large, a gate opening limit function is provided; when the current gate opening exceeds the limit value, the lifting control loop is cut off, thus preventing the gate from rising further.) If the required opening is less than the current opening, the system controls the gate to descend until the gate opening equals the required opening, at which point the gate stops descending.

[0043] In this embodiment, real-time data interaction and protection also includes the linkage of a data interaction protocol stack and a multi-level protection mechanism, as follows: a. The data interaction protocol stack consists of a physical layer, a transport layer, and an application layer. The physical layer adopts the IEEE 802.3 Ethernet standard, the transport layer encapsulates real-time data packets based on the UDP protocol, and the application layer defines a custom binary frame structure. b. The multi-level protection mechanism linkage is divided into primary protection, secondary protection and manual protection. Among them, the primary protection issues an early warning and reduces the speed to 50% when the load is greater than 105% of the rated value. The secondary protection triggers a 0.2s-level emergency stop when the load is greater than 115% of the rated value or the opening change rate is greater than 8cm / s². The manual protection is to manually confirm the protection reset on site. Preferably, the multi-level protection mechanism linkage is as follows: a1. Primary protection ( (This includes reducing the speed to 50% and uploading a warning code 0xF1.) a2. Secondary protection ( or (This refers to the hardware emergency stop circuit, which has a response time of ≤100ms.) a3. Protection reset must be met simultaneously: press the local confirmation button + load recovery to normal for 5 seconds.

[0044] This application imports flow rate, opening degree, and reservoir water level curves into a program, enabling the gate to automatically adjust. Based on the given flow rate, the gate control detection curve automatically controls the gate to a certain opening degree to ensure a constant flow rate. In addition, through program-defined opening degree limits, when the upper limit of the opening degree is reached, the PLC activates a relay to automatically open contact K6, thus cutting off the control circuit interlock. When the lower limit of the opening degree is reached, the PLC activates a relay to automatically open contact K7, thus cutting off the control circuit interlock. This prevents the gate from operating automatically due to human error or contact adhesion.

[0045] When in use, firstly, the entire gate control cabinet of the main canal is upgraded, the gate control cabinet and accessories of the main canal are replaced, and a set of water level gauges is installed upstream of the reservoir in the main canal (for the control system to collect data).

[0046] Secondly, the upper computer monitoring system communicates with the PLC of the local canal gate control system. The Modbus TCP protocol is used to collect data and hard contacts for control, so as to realize remote control of the central canal gate, real-time fault monitoring, real-time monitoring of the opening degree, flow rate and other operation and alarm data of the central canal gate.

[0047] Furthermore, by developing a program that corresponds to the flow rate curve of the reservoir's upstream water level, the main canal gate control system program is equipped with the ability to automatically adjust the opening of the main canal gates based on the flow rate curve of the upstream water level of the reservoir.

[0048] Finally, by adding a protective interlock to the control circuit, dual protection is adopted. By setting the program opening limit, when the upper limit of the opening is reached, the PLC activates the relay to automatically lift the K6 contact to open, thereby cutting off the control circuit interlock; when the lower limit of the opening is reached, the PLC activates the relay to automatically lift the K7 contact to open, thereby cutting off the control circuit interlock.

[0049] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An automatic adjustment and control system for water level and flow rate of a canal gate, the system comprising a submersible level gauge, a frequency converter, an opening load cell, a PLC controller, and a touch screen, characterized in that, The automatic adjustment control of this system includes the following steps: Step S1, Multi-source signal acquisition, includes the following process: S1-1. Real-time acquisition of reservoir water level using an immersion level gauge and conversion into a 4-20mA electrical signal; S1-2. The gate opening value and weight data are simultaneously acquired using an opening load cell; S1-3. Receive the target flow command issued by the central control room monitoring system; Step S2, Control Mode Decision, includes the following process: S2-1. Perform quality judgment on the water level signal. If the signal is valid, trigger the automatic control mode. If the signal fails, trigger the remote control mode and send a fault alarm. S2-2. When responding to local operation instructions, local mode is triggered; Step S3, Execution of Modular Control, including automatic control mode, remote control mode, and local mode, specifically involves the following process: S3-1. Automatic control mode; S3-2. Remote control mode: Parses operation commands issued by the monitoring system and executes gate lifting, lowering, stopping, or emergency stop. S3-3. Local mode; Step S4, Real-time Data Interaction and Protection, includes the following processes: S4-1. Upload gate opening, load, water level, control status and alarm data to the monitoring system; S4-2. When the load cell detects an abnormal weight, it triggers the emergency stop protection and uploads an alarm.

2. The automatic adjustment and control system for water level and flow rate of a main canal gate according to claim 1, characterized in that, The automatic control mode described in step S3 includes the following process; a. Based on the target flow rate and the current water level, calculate the target opening by calling the pre-stored opening-flow mathematical model in the PLC; b. Perform closed-loop control of the opening degree. If the target opening degree is greater than the current opening degree, drive the gate to rise until the two are the same. If the target opening degree is less than the current opening degree, drive the gate to fall until the two are the same. c. When the real-time opening degree is greater than or equal to the preset limit threshold, the lifting action is forcibly terminated.

3. The automatic adjustment and control system for water level and flow rate of a main canal gate according to claim 1, characterized in that, The in-situ mode described in step S3 is the following process: a. Directly control the gate in response to start / stop commands from local buttons; b. Adjust the inverter output frequency via the touchscreen to change the operating speed.

4. The automatic adjustment and control system for water level and flow rate of a main canal gate according to claim 1, characterized in that, The aperture-flow mathematical model is constructed as follows: a1. At N typical water level values The measured flow rate data is given below, with each water level value set at an arithmetic interval. Open the gate, At each opening point L j After stabilization, the corresponding flow rate Q is collected using an ultrasonic flow meter. j ; a2. For each water level segment An independent mapping function is constructed, and a continuous curve of opening degree-flow rate is generated using cubic spline interpolation. This curve is stored in the PLC as a two-dimensional lookup table, with the row index being the normalized water level value and the column index being the opening degree value. a3. Online model correction mechanism: when the deviation between measured and predicted flow continues... At that time, the curve coefficient self-learning is triggered, and then... Update the mapping relationship. Parameters optimized for scrolling.

5. The automatic adjustment and control system for water level and flow rate of a main canal gate according to claim 4, characterized in that, The construction function of the opening-flow mathematical model Including the following: a1. At five characteristic water points, the flow rate was adjusted in increments of ΔL = 10 cm, and the stable flow rate Q was recorded using an ultrasonic flow meter. Among them, 5 characteristic water points are To form a dataset ； a2. For each water level segment, construct a continuous function using cubic spline interpolation. Inverse function generation ; Among them, the water level section is extracted as ; The parameterized matrix stored in PLC a3. is: Where row index i corresponds to the normalized water level, column index j corresponds to the openness, and element This represents the flow rate.

6. The automatic adjustment and control system for water level and flow rate of a main canal gate according to claim 1, characterized in that, The quality judgment mentioned in step S2 specifically includes signal validity verification and fault diagnosis and handling, which are divided into the following processes: a1. Signal validity verification involves range detection and fluctuation detection. If the current value is <3.8mA or >20.5mA for 500ms, it is determined to be out of range. Calculate the standard deviation of 10 sampling points within the sliding window. ,like Then the fluctuation is determined to be abnormal; a2. Fault diagnosis and handling: A retry mechanism is initiated for abnormal signals. Three consecutive data collections are performed at 100ms intervals. If the abnormality persists after the retry, it is marked as a "hard fault" and the automatic mode is locked. If the retry is successful, it is marked as a "soft fault" but the automatic mode is maintained.

7. The automatic adjustment and control system for water level and flow rate of a main canal gate according to claim 2, characterized in that, The automatic control mode described in step S3 also includes a dual-loop structure for the opening closed-loop control and variable speed control for gate lifting / lowering, specifically as follows: a1. The outer loop is the position loop, and the PID controller input opening deviation. Output speed command proportional term Integral term s, differential term s; a2. The inner loop is the speed loop, and the PI controller inputs the speed deviation. It outputs motor torque commands, with the torque limit set at 75% to 85% of the motor's rated torque. a3. Speed ​​control for gate lifting / lowering, when When operating at 100% of rated speed, At that time, it runs at 60% of the rated speed. At that time, it operates at 30% of the rated speed.

8. The automatic adjustment and control system for water level and flow rate of a main canal gate according to claim 7, characterized in that, The speed control in the automatic control mode satisfies the following parameters: Position loop PID parameters: Velocity feedforward compensation: in, .

9. A control system for automatic adjustment of water level and flow rate of a main canal gate according to claim 1, characterized in that, The real-time data interaction and protection described in step S4 also includes the linkage of a data interaction protocol stack and a multi-level protection mechanism, as follows: a. The data interaction protocol stack consists of a physical layer, a transport layer, and an application layer. The physical layer adopts the IEEE 802.3 Ethernet standard, the transport layer encapsulates real-time data packets based on the UDP protocol, and the application layer defines a custom binary frame structure. b. The multi-level protection mechanism is divided into primary protection, secondary protection and manual protection. Primary protection issues an early warning and reduces the speed to 50% when the load is greater than 105% of the rated value. Secondary protection triggers a 0.2s emergency stop when the load is greater than 115% of the rated value or the opening change rate is greater than 8cm / s². Manual protection is to manually confirm the protection reset on site.

10. A control system for automatic adjustment of water level and flow rate of a main canal gate according to claim 9, characterized in that, The aforementioned multi-level protection mechanism linkage specifically refers to: a1. Primary protection ( (This includes reducing the speed to 50% and uploading a warning code 0xF1.) a2. Secondary protection or Among them, the hardware emergency stop circuit has a response time of ≤100ms; a3. Protection reset must be met simultaneously: press the local confirmation button + load recovery to normal for 5 seconds.

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