Water pump multi-mode intelligent control method based on PLC

Abstract

The invention belongs to the technical field of intelligent control, and particularly relates to a water pump multi-mode intelligent control method based on a PLC. Operation parameters are acquired in real time through a data acquisition module, a target mode is selected from constant-pressure water supply, constant-flow water supply, energy-saving optimization and fault emergency modes through a mode judgment module according to preset triggering conditions, and an operation strategy including a start-stop sequence, a target rotating speed, a frequency converter output frequency and a pressure set value is generated through a strategy generation module. The control execution module converts the strategy into a control instruction and outputs the control instruction to the water pump driving module, and linkage operation and mode switching of the multiple water pumps are achieved in combination with the mode linkage module. And the recording and optimizing module is used for storing and analyzing the operation data and optimizing mode switching conditions and operation strategies. Self-adaptive control and multi-pump cooperative scheduling in multiple modes are achieved, the stability and energy saving performance of a water supply system are improved, and the service life of equipment is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of intelligent control, and in particular relates to a multi-mode intelligent control method for a water pump based on PLC. Background Art

[0002] Currently, water supply systems are widely used in municipal water supply, industrial circulating water, building fire protection, and agricultural irrigation. Water pumps, as core power equipment, have a direct impact on the stability and energy consumption of water supply systems through their operation and control. Traditional water pump control methods rely on manual operation or a single constant pressure and constant flow mode, operating with fixed parameters to meet water demand. However, when water demand fluctuates significantly or the operating environment changes frequently, fixed control modes are difficult to adapt to actual operating conditions in a timely manner. This can easily lead to problems such as large pressure fluctuations, high energy consumption, and frequent starting and stopping of water pumps, impacting equipment life and system economics.

[0003] With the popularization of PLC technology and the advancement of industrial automation, water pump control systems have gradually integrated multiple operating modes and use sensors to collect real-time parameters such as flow, pressure, and liquid level. However, existing multi-mode control systems still have relatively simple mode switching strategies, typically relying on threshold triggering of a single parameter and lacking dynamic analysis and optimization of the comprehensive state of multiple parameters. Furthermore, when multiple water pumps operate in conjunction, existing systems lack coordination of the operating states of each pump, which can easily lead to uneven load distribution, delayed response, or sudden pressure changes during the switching process.

[0004] Therefore, there is an urgent need for a water pump control method that can combine the real-time control capabilities of PLC, comprehensively analyze the operating status of multiple parameters, and realize intelligent scheduling in multi-mode operation and mode switching, so as to improve the reliability, economy and adaptability of the water supply system. Summary of the Invention

[0005] In view of the above problems, the present invention aims to propose a multi-mode intelligent control method for a water pump based on PLC, comprising the following steps: S1. Operation data collection and input processing: Set multiple operation monitoring points and collect operation parameters in real time through flow sensors, pressure sensors and liquid level sensors; S2. Control mode selection and condition determination: Based on the operating parameter information, call the preset control mode library, including constant pressure water supply mode, constant flow water supply mode, energy-saving optimization mode and fault emergency mode; compare the current multi-dimensional operating parameters with the trigger conditions of each mode to determine the appropriate target control mode; S3. Operation strategy generation and parameter setting: Generate an operation strategy from a strategy template according to the target control mode. The operation strategy includes the pump start and stop sequence, target speed, inverter output frequency, and pressure setting value; S4, Execute control instructions and dynamic adjustment: Convert the operation strategy into control instructions executable by the PLC, output them to the water pump drive module for execution, and dynamically adjust the output frequency, start and stop status, and the number of parallel water pumps based on the real-time collected operating parameters; S5, mode switching and linkage control: When the operating conditions change beyond the set threshold, it automatically switches to other adaptation modes according to the priority rules, and establishes a linkage operation relationship between multiple water pumps; S6. Operation status recording and optimization update: record the operation data, energy consumption indicators and fault alarm information in each mode, generate a historical operation record table, and optimize the mode switching conditions and operation strategy parameters based on the historical data.

[0006] As a preferred technical solution, in step S2, the triggering condition of the control mode includes at least one of a flow threshold, a pressure threshold, a liquid level threshold and an equipment operation time threshold.

[0007] As an optimal technical solution, when multiple control mode triggering conditions are met, the target control mode is selected in the following priority order: the first priority is the fault emergency mode; the second priority is the constant pressure water supply mode; the third priority is the constant flow water supply mode; and the fourth priority is the energy-saving optimization mode.

[0008] As a preferred technical solution, step S4 includes: S4-1, output start-stop control signal: send start or stop instructions to the water pump drive module according to the operation strategy; S4-2, output frequency control signal: adjust the inverter output frequency according to the deviation between the real-time pressure or flow and the set value; S4-3. Execute the pump group switching operation: when the operating conditions meet the preset switching standards, switch the working status of the running pump and the standby pump.

[0009] As a preferred technical solution, in S4-3, the preset switching criteria include any one or more of the cumulative operating time, operating temperature rise, vibration amplitude and energy efficiency ratio change.

[0010] As a preferred technical solution, in step S5, the priority rule method includes: S5-1. Global operating condition matrix generation: When the mode switch is triggered, a multi-dimensional operating condition matrix is ​​constructed with each pump as a row and instantaneous flow, outlet pressure, input power, cumulative operating time, temperature rise, vibration amplitude and frequency setting value as columns. The cumulative parameters and amplitude parameters are respectively subjected to interval normalization and zero-mean normalization to obtain a standardized operating condition matrix; S5-2. Window Statistics and Derived Index Calculation: Within the PLC fixed-length sampling window, the mean, range, and variance of each column of the standardized operating condition matrix are calculated sequentially to form a statistical matrix. Simultaneously, by applying frequency perturbations to the target pump channel, derived parameters are measured, including: pressure rise rate, flow recovery rate, and energy consumption per unit frequency change rate. These derived parameters are then combined with the standardized operating condition matrix to form an extended operating condition characteristic matrix. S5-3. Candidate pump group screening: Set the pump group feasibility criteria, including: T1: The safety performance judgment conditions are formed based on the safety threshold, including vibration not exceeding the set value, temperature rise not exceeding the set value, and frequency not exceeding the set upper limit; T2 uses the steady-state performance threshold to form steady-state performance judgment conditions, including pressure recovery time not exceeding the set value, flow stabilization time not exceeding the set value, and energy consumption change rate not exceeding the set value; The feasibility criteria of the pump group are compared row by row with the extended working condition characteristic matrix to obtain the feasible water pump set, and the parameters of the pump group combination of the feasible set are aggregated to generate the combination characteristic matrix; S5-4. Determine the optimal pump group: In the combination characteristic matrix, use pressure recovery time, flow stabilization time, energy consumption change rate, and newly added start and stop times as optimization objectives to determine the Pareto optimal set. Within this set, minimize newly added start and stop times, pressure recovery time, and energy consumption change rate in order of priority, and select a unique pump group combination as the current operating combination. S5-5, hysteresis and backtracking control: After switching to a new combination, if the outlet pressure drop rate or flow rate drop rate is detected to exceed the set limit value within a PLC scan cycle, it will fall back to the operating combination before switching, and set symmetrical hysteresis intervals on both sides of the trigger threshold. The matrix is ​​updated only outside the hysteresis interval.

[0011] As a preferred technical solution, in step S6, the historical operation record table is stored in the form of a structured data table, including a timestamp, an operation mode number, an energy consumption value, an output frequency, a flow value, and a pressure value.

[0012] As a preferred technical solution, the optimization update of the mode switching conditions is implemented based on a weighted algorithm, which calculates a comprehensive score based on energy consumption weight, water supply stability weight and equipment health status weight.

[0013] The present invention also provides a PLC-based multi-mode intelligent control system for a water pump, which is used to implement the method described above, including: A data acquisition module, configured to obtain water pump operating parameters and water supply system status parameters and generate first data information; A mode determination module, configured to determine and select a target control mode according to the first data information; A strategy generation module is used to generate an operation strategy that matches the target control mode; The control execution module is used to convert the operation strategy into control instructions and output them to the water pump drive module for execution; Mode linkage module, used to establish linkage operation relationships between multiple water pumps and perform mode switching; The recording and optimization module is used to store operation data and optimize mode switching conditions and operation strategy parameters based on historical data.

[0014] The present invention also provides a PLC-based multi-mode intelligent control terminal for a water pump, comprising at least one processor and a memory in communication with the processor, wherein a computer program is stored in the memory, and when the program is executed by the processor, the processor is enabled to execute the described method.

[0015] Beneficial effects: This invention achieves refined management of the pump's operating status by introducing a multi-mode operation and real-time operating matrix scheduling algorithm into the PLC control system. Compared to traditional methods that rely on a single parameter threshold to switch modes, this invention integrates multi-dimensional parameters such as flow rate, pressure, liquid level, operating time, temperature rise, and vibration amplitude for standardized processing and window statistical analysis. It also combines frequency perturbation to obtain dynamic response indicators. This allows for comprehensive multi-conditional judgment during mode switching and pump group selection, significantly improving switching accuracy and adaptability.

[0016] In the coordinated operation of multiple water pumps, the present invention effectively avoids pressure fluctuations and flow instability caused by improper switching through a dual screening mechanism of safety performance and steady-state performance, and uses the Pareto optimization method to achieve a balance between pressure recovery time, flow stabilization time, energy consumption change rate and the number of additional start and stop times, thereby achieving a balance between water supply stability and energy-saving effects.

[0017] In addition, the present invention has set up a hysteresis and backtracking mechanism. If a rapid deterioration of key operating parameters is detected after switching, it can immediately fall back to a stable combination to prevent mechanical wear and system impact caused by frequent switching, extend the service life of the equipment and reduce maintenance costs, thereby improving the reliability, economy and intelligence level of the water supply system as a whole. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the method flow of the present invention; Figure 2 Schematic diagram of the system structure of the present invention. DETAILED DESCRIPTION

[0019] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the examples. The examples are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0020] Example 1 according to Figure 1 As shown, this embodiment provides a PLC-based multi-mode intelligent control method for water pumps, which is applicable to various water supply system scenarios such as municipal water supply, industrial circulating water, building fire protection, and agricultural irrigation. It can realize multi-mode operation, intelligent switching and multi-pump coordinated scheduling of water pumps under different working conditions, thereby taking into account water supply stability, energy consumption optimization and equipment life extension.

[0021] S1. Operation data collection and input processing: In the PLC control system, multiple operation monitoring points are set at key nodes of the pipe network, the main water outlet pipe of the pump room, and the water pump outlet according to the structure of the water supply system and water demand.

[0022] Each monitoring point is equipped with a flow sensor, a pressure sensor and a liquid level sensor. The flow sensor is used to measure the instantaneous flow rate, the pressure sensor is used to measure the outlet pressure or the pipe network pressure, and the liquid level sensor is used to monitor the liquid level height of the water storage tank or the high-level water tank.

[0023] The PLC uses a high-speed data acquisition module to collect operating parameters in seconds or less. After collection, the data undergoes preprocessing, including signal filtering, outlier removal, and data standardization, to ensure the stability and accuracy of the data fed into the subsequent control logic. The processed operating parameters are converted into primary data information in a unified format, providing the data foundation for mode determination.

[0024] S2. Control mode selection and condition determination: The control mode library is preset inside the PLC, including four operating modes: constant pressure water supply mode, constant flow water supply mode, energy-saving optimization mode and fault emergency mode.

[0025] Mode selection is determined based on the degree of matching between the first data information and each mode triggering condition. The mode triggering condition is composed of multi-dimensional operating parameters, including at least one or more of a flow threshold, a pressure threshold, a liquid level threshold, and a device operation time threshold.

[0026] When the trigger conditions of multiple modes are met, selection is made according to the priority rules: the first priority is the fault emergency mode, which is used to deal with emergencies such as sensor failure, abnormal vibration of the pump body, and a sharp drop in outlet pressure; the second priority is the constant pressure water supply mode, which keeps the pipe network pressure stable within the set range; the third priority is the constant flow water supply mode, which is used for production or process water supply that requires a stable flow rate; the fourth priority is the energy-saving optimization mode, which reduces energy consumption while meeting water supply needs.

[0027] The PLC executes the mode decision logic every time it scans the loop, enabling real-time switching condition monitoring.

[0028] S3. Operation strategy generation and parameter setting: Once the target control mode is determined, the PLC generates an operating strategy based on the corresponding strategy template. The operating strategy includes the pump start and stop sequence (such as alternating or step-by-step start and stop of multiple pumps), target speed, inverter output frequency, pressure setpoint, etc.

[0029] For constant pressure water supply mode, the strategy template will use the pressure setpoint as the primary control target and adjust the output frequency through closed-loop PID control; In constant flow mode, the flow set value takes priority; in energy-saving optimization mode, the number and frequency of working pumps will be dynamically adjusted according to real-time demand to try to make the pump group operate in the high-efficiency range; In fault emergency mode, the faulty pump will be shut down immediately and the backup pump will be switched to ensure uninterrupted water supply.

[0030] When generating strategies, the PLC will make corrections based on real-time operating parameters, such as correcting the target pressure based on liquid level changes to adapt to instantaneous demand changes.

[0031] S4. Execution control instructions and dynamic adjustment: The PLC converts the generated operation strategy into executable control instructions and sends them to the drive modules of each water pump through the output module. This process includes three aspects: S4-1 outputs the start / stop control signal: sends a start or stop signal to the target water pump drive module according to the start / stop sequence in the strategy, so that the water pump can be put into operation or stopped as planned.

[0032] S4-2 Output frequency control signal: According to the deviation between the real-time pressure or flow and the set value, the output frequency of the inverter is adjusted through the analog quantity or communication interface to ensure that the operating parameters fluctuate within the allowable range.

[0033] S4-3 Execute pump group switching operation: When the operating conditions reach the preset switching standards (including indicators such as cumulative operating time, operating temperature rise, vibration amplitude or energy efficiency ratio change), the PLC executes pump group switching and switches the operating pump to the standby pump to ensure balanced use of the equipment and reduce the risk of fatigue operation of a single pump.

[0034] During the dynamic adjustment process, the PLC will monitor the execution effect in real time. If it finds that the adjusted parameters do not meet expectations, it will continue to correct the control instructions in the next scan cycle to form a closed-loop adjustment.

[0035] S5, mode switching and linkage control: When the operating conditions change beyond the set threshold, the PLC automatically switches to other adaptation modes according to the priority rules and establishes a linkage operation relationship between multiple water pumps. To achieve efficient switching and stable linkage, this embodiment adopts a real-time working condition matrix scheduling algorithm: S5-1 Global operating condition matrix generation: When the mode switch is triggered, a multi-dimensional operating condition matrix is ​​constructed with each pump as a row and instantaneous flow, outlet pressure, input power, cumulative operating time, temperature rise, vibration amplitude and frequency setting value as columns. Different types of parameters are interval-normalized and zero-mean-normalized to obtain a standardized operating condition matrix.

[0036] S5-2 Window statistics and derived index calculation: Within a fixed sampling window, the mean, range, and variance of each column of the standardized operating condition matrix are calculated to form a statistical matrix; a small-amplitude frequency perturbation is applied to the target pump channel to measure derived parameters, including pressure rise rate, flow recovery rate, and unit frequency energy consumption change rate, which are then merged with the statistical matrix to form an extended operating condition characteristic matrix.

[0037] S5-3 Candidate Pump Set Screening: Pump set feasibility criteria are used for screening. Safety performance criteria include ensuring that vibration, temperature rise, and frequency do not exceed set thresholds. Steady-state performance criteria include ensuring that pressure recovery time, flow rate stabilization time, and energy consumption change rate do not exceed set thresholds. The criteria are applied row by row in the expanded matrix to obtain a feasible set of pumps. Their combined parameters are aggregated to form a combined feature matrix.

[0038] S5-4 Determination of the optimal pump group: In the combination characteristic matrix, with pressure recovery time, flow stabilization time, energy consumption change rate and newly added start and stop times as optimization objectives, determine the Pareto optimal set, and minimize the newly added start and stop times, pressure recovery time, and energy consumption change rate in order of priority, and select the only pump group combination as the current operating combination.

[0039] S5-5 Hysteresis and backtracking control: After switching to a new combination, if the outlet pressure or flow rate drop rate exceeds the limit threshold within a PLC scan cycle, it will immediately fall back to the operating combination before switching, and set symmetrical hysteresis intervals on both sides of the threshold to prevent frequent switching. Matrix updates are only performed outside the hysteresis interval.

[0040] S6. Operation status record and optimization update: During operation, the PLC records operating data, energy consumption indicators, and fault alarm information for each mode in real time, storing them in a structured data table containing fields such as timestamp, operating mode number, energy consumption value, output frequency, flow rate, and pressure value. This historical data is regularly fed into an optimization algorithm, which calculates a comprehensive score based on weights for energy consumption, water supply stability, and equipment health. This allows for optimization and update of mode switching conditions and operating strategy parameters. These updated parameters can be directly written into the PLC program, enhancing adaptive control capabilities.

[0041] Example 2 like Figure 2As shown, this embodiment provides a PLC-based multi-mode intelligent control system for water pumps, which can collect the operating status of water pumps and water supply systems in real time, and realize mode determination, operation strategy generation, control instruction execution and multi-pump coordinated linkage in combination with multi-mode control strategies, and optimize strategies based on historical data during long-term operation, thereby reducing energy consumption and extending equipment life while ensuring water supply stability.

[0042] The system is particularly suitable for scenarios such as municipal water supply, industrial circulating water, building fire protection, and agricultural irrigation that require the coordinated operation of multiple water pumps.

[0043] This system includes data acquisition module, pattern determination module, strategy generation module, control execution module, pattern linkage module, and recording and optimization module. The structure and function of each module are as follows.

[0044] 1. Data acquisition module: The data acquisition module is used to obtain the water pump operating parameters and water supply system status parameters and generate first data information. It is the basic data source of this system.

[0045] Hardware composition: includes flow sensor, pressure sensor, liquid level sensor, temperature sensor, vibration sensor, etc., as well as signal conditioning circuit connected to PLC input port or acquisition module.

[0046] Flow sensors are installed at the outlet of each water pump or at key locations in the pipeline network, pressure sensors are installed at the pump outlet pipe section and the end of the pipeline network, liquid level sensors are installed in the water storage tank or high-level water tank, and temperature and vibration sensors are installed on the water pump bearings or motor housing.

[0047] Data acquisition method: Using a PLC high-speed acquisition card or remote I / O module, continuously collects data with a sampling period of milliseconds or seconds. To avoid noise interference, the acquisition module performs signal filtering and amplitude stabilization before the data enters the PLC.

[0048] Data preprocessing: This includes outlier removal (such as removing instantaneous mutation values ​​during sampling), signal de-jittering, data unit unification, and standardization to ensure that different types of parameters are comparable in subsequent judgments.

[0049] Data encapsulation and output: Encapsulate the sensor data into the first data information according to the predefined data structure, store it uniformly in the real-time data area of ​​the PLC memory, and transmit it to the mode determination module at regular intervals.

[0050] 2. Mode determination module: The mode determination module is used to determine and select a target control mode according to the first data information, and directly determine the operation strategy type of the water pump.

[0051] Mode library composition: The system has four built-in operating modes: constant pressure water supply mode, constant flow water supply mode, energy-saving optimization mode and fault emergency mode.

[0052] Trigger Condition Definition: Each mode corresponds to a set of trigger conditions, including one or more of the following: flow rate threshold, pressure threshold, liquid level threshold, and equipment operating time threshold. For example, the constant pressure water supply mode is triggered when the pipe network pressure falls below the set lower limit and the liquid level rises above the safe height; the energy-saving optimization mode is triggered when both pressure and flow rate are within the set range and the current energy efficiency ratio falls below the energy-saving reference value.

[0053] Multi-mode conflict handling: When multiple mode trigger conditions are met at the same time, the system makes decisions in order of priority, which are: fault emergency mode, constant pressure water supply mode, constant flow water supply mode, and energy-saving optimization mode.

[0054] Logical implementation: In the PLC program, the first data information is compared with each mode trigger condition in real time in a cyclic scanning manner, and a unique target mode signal is output to the strategy generation module within a single scanning cycle in combination with the priority rule.

[0055] 3. Strategy generation module: The strategy generation module is used to generate an operation strategy that matches the target control mode and is the middle layer between mode determination and execution control.

[0056] Strategy template library: Each mode is pre-configured with a strategy template, including parameters such as pump start and stop sequence, target speed, inverter output frequency, pressure set value, flow set value, pump group switching interval, etc.

[0057] Parameter Correction: The strategy generation module corrects the template based on the current operating parameters. For example, in constant pressure water supply mode, if the liquid level approaches the lower limit, the target pressure is lowered to reduce the pump load; in energy-saving optimization mode, if the current energy efficiency ratio is higher than the reference value, the number of operating pumps is reduced and the frequency of operation is increased.

[0058] Output strategy: The revised strategy, including all necessary execution instruction parameters, is uniformly output to the control execution module. This strategy can be issued directly through the PLC program or after strategy verification through communication between the PLC and the host computer.

[0059] 4. Control execution module: The control execution module is used to convert the operation strategy into executable control instructions and output them to the water pump drive module for execution.

[0060] Start and stop control: Convert the start and stop instructions in the strategy into digital output signals, and send them to the contactors or soft starters of each water pump through the PLC output port or communication interface to start and stop the water pump.

[0061] Frequency control: Convert the target frequency in the strategy into an analog signal or communication parameter, and send it through the inverter control interface to achieve speed regulation of the water pump motor.

[0062] Pump group switching: According to the pump group switching conditions set in the strategy (accumulated operating time, operating temperature rise, vibration amplitude, energy efficiency ratio change, etc.), switching between the operating pump and the standby pump is executed when the conditions are met to ensure balanced use of the pump group.

[0063] Dynamic adjustment: During the execution process, the control execution module adjusts the frequency, start and stop status and the number of running pumps in a timely manner according to the real-time collected operating data, forming a closed-loop control to ensure that the strategic goals are continuously achieved.

[0064] 5. Mode linkage module: The mode linkage module is used to establish a linkage operation relationship between multiple water pumps and perform mode switching to ensure smooth system operation.

[0065] Real-time operating condition matrix scheduling: When the mode switch is triggered, the mode linkage module constructs a multi-dimensional operating condition matrix based on the instantaneous flow, outlet pressure, input power, operating time, temperature rise, vibration amplitude and frequency setting values, and performs standardization and statistical analysis.

[0066] Candidate pump group screening: Filter feasible pump group combinations based on safety performance judgment conditions (vibration, temperature rise, and frequency do not exceed the threshold) and steady-state performance judgment conditions (pressure recovery time, flow stabilization time, and energy consumption change rate do not exceed the threshold).

[0067] Determination of the optimal pump group: Among the feasible combinations, the pressure recovery time, flow stabilization time, energy consumption change rate and the number of new starts and stops are comprehensively optimized, and the current best combination is selected using the Pareto optimal principle.

[0068] Hysteresis and backtracking mechanism: After switching, if it is detected that the pressure or flow rate drops faster than the limit threshold, it will immediately fall back to the combination before switching. At the same time, a hysteresis interval is set to prevent frequent switching.

[0069] 6. Recording and optimization module: The recording and optimization module is used to store and analyze operating data for a long time to optimize mode switching conditions and operating strategies.

[0070] Data recording: Record the timestamp, operation mode number, energy consumption value, output frequency, flow value, pressure value and other information of each operation cycle in a structured data table.

[0071] Data analysis: Regularly analyze historical data, calculate energy consumption weights, water supply stability weights, and equipment health status weights to form a comprehensive score.

[0072] Parameter optimization: Adjust mode switching conditions and strategy template parameters based on the scoring results, such as increasing the switching delay of a certain mode, adjusting the pump group switching interval, and optimizing the frequency setting value.

[0073] Application of optimization results: Write the optimized parameters directly into the PLC program or strategy template to achieve adaptive control in the next operation cycle.

[0074] 7. System integration and operation process: Each module interacts with the other through the PLC's internal data area and communication interfaces: the data acquisition module transmits real-time parameters to the mode determination module; the mode determination module transmits target mode information to the strategy generation module; the strategy generation module transmits the operating strategy to the control execution module; the control execution module drives the pump and provides real-time feedback on the execution status to the mode linkage module; the mode linkage module adjusts the pump group's operation when switching conditions are detected; and the recording and optimization module continuously receives data from each module for storage and analysis. The entire system operates under the cyclic scanning of the PLC control program, ensuring millisecond-level response and continuous control.

[0075] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-mode intelligent control method for a water pump based on PLC, characterized in that: The following steps are involved: S1. Operation data collection and input processing: Set multiple operation monitoring points and collect operation parameters in real time through flow sensors, pressure sensors and liquid level sensors; S2. Control mode selection and condition determination: Based on the operating parameter information, call the preset control mode library, including constant pressure water supply mode, constant flow water supply mode, energy-saving optimization mode and fault emergency mode; compare the current multi-dimensional operating parameters with the trigger conditions of each mode to determine the appropriate target control mode; S3. Operation strategy generation and parameter setting: Generate an operation strategy from a strategy template according to the target control mode. The operation strategy includes the pump start and stop sequence, target speed, inverter output frequency, and pressure setting value; S4, Execute control instructions and dynamic adjustment: Convert the operation strategy into control instructions executable by the PLC, output them to the water pump drive module for execution, and dynamically adjust the output frequency, start and stop status, and the number of parallel water pumps based on the real-time collected operating parameters; S5, mode switching and linkage control: When the operating conditions change beyond the set threshold, it automatically switches to other adaptation modes according to the priority rules, and establishes a linkage operation relationship between multiple water pumps; S6. Operation status recording and optimization update: record the operation data, energy consumption indicators and fault alarm information in each mode, generate a historical operation record table, and optimize the mode switching conditions and operation strategy parameters based on the historical data.

2. The PLC-based multi-mode intelligent control method for a water pump according to claim 1, characterized in that: In step S2, the triggering condition of the control mode includes at least one of a flow threshold, a pressure threshold, a liquid level threshold, and an equipment operation time threshold.

3. The multi-mode intelligent control method for a water pump based on PLC according to claim 2, characterized in that: When multiple control mode triggering conditions are met, the target control mode is selected in the following priority order: the first priority is the fault emergency mode; the second priority is the constant pressure water supply mode; the third priority is the constant flow water supply mode; and the fourth priority is the energy-saving optimization mode.

4. The multi-mode intelligent control method for a water pump based on PLC according to claim 1, characterized in that: Step S4 includes: S4-1, output start-stop control signal: send start or stop instructions to the water pump drive module according to the operation strategy; S4-2, output frequency control signal: adjust the inverter output frequency according to the deviation between the real-time pressure or flow and the set value; S4-3. Execute the pump group switching operation: when the operating conditions meet the preset switching standards, switch the working status of the running pump and the standby pump.

5. The PLC-based multi-mode intelligent control method for a water pump according to claim 4, characterized in that: In the above S4-3, the preset switching criteria include any one or more of the cumulative operating time, operating temperature rise, vibration amplitude and energy efficiency ratio change.

6. The multi-mode intelligent control method for a water pump based on PLC according to claim 1, characterized in that: In step S5, the priority rule method includes: S5-1. Global operating condition matrix generation: When the mode switch is triggered, a multi-dimensional operating condition matrix is ​​constructed with each pump as a row and instantaneous flow, outlet pressure, input power, cumulative operating time, temperature rise, vibration amplitude and frequency setting value as columns. The cumulative parameters and amplitude parameters are respectively subjected to interval normalization and zero-mean normalization to obtain a standardized operating condition matrix; S5-2. Window Statistics and Derived Index Calculation: Within the PLC fixed-length sampling window, the mean, range, and variance of each column of the standardized operating condition matrix are calculated sequentially to form a statistical matrix. Simultaneously, by applying frequency perturbations to the target pump channel, derived parameters are measured, including: pressure rise rate, flow recovery rate, and energy consumption per unit frequency change rate. These derived parameters are then combined with the standardized operating condition matrix to form an extended operating condition characteristic matrix. S5-3. Candidate pump group screening: Set the pump group feasibility criteria, including: T1: The safety performance judgment conditions are formed based on the safety threshold, including vibration not exceeding the set value, temperature rise not exceeding the set value, and frequency not exceeding the set upper limit; T2 uses the steady-state performance threshold to form steady-state performance judgment conditions, including pressure recovery time not exceeding the set value, flow stabilization time not exceeding the set value, and energy consumption change rate not exceeding the set value; The feasibility criteria of the pump group are compared row by row with the extended working condition characteristic matrix to obtain the feasible water pump set, and the parameters of the pump group combination of the feasible set are aggregated to generate the combination characteristic matrix; S5-4. Determine the optimal pump group: In the combination characteristic matrix, use pressure recovery time, flow stabilization time, energy consumption change rate, and newly added start and stop times as optimization objectives to determine the Pareto optimal set. Within this set, minimize newly added start and stop times, pressure recovery time, and energy consumption change rate in order of priority, and select a unique pump group combination as the current operating combination. S5-5, hysteresis and backtracking control: After switching to a new combination, if the outlet pressure drop rate or flow rate drop rate is detected to exceed the set limit value within a PLC scan cycle, it will fall back to the operating combination before switching, and set symmetrical hysteresis intervals on both sides of the trigger threshold. The matrix is ​​updated only outside the hysteresis interval.

7. The multi-mode intelligent control method for a water pump based on PLC according to claim 1, characterized in that: In step S6, the historical operation record table is stored in the form of a structured data table, including a timestamp, an operation mode number, an energy consumption value, an output frequency, a flow value, and a pressure value.

8. The multi-mode intelligent control method for a water pump based on PLC according to claim 1, characterized in that: The mode switching condition is adjusted based on a weighted algorithm during the optimization and updating process, and the weighted algorithm calculates a comprehensive score based on the energy consumption weight, the water supply stability weight, and the equipment health status weight.

9. A multi-mode intelligent control system for water pumps based on PLC, used to implement the method according to any one of claims 1 to 8, characterized in that: include: A data acquisition module, configured to obtain water pump operating parameters and water supply system status parameters and generate first data information; A mode determination module, configured to determine and select a target control mode according to the first data information; A strategy generation module is used to generate an operation strategy that matches the target control mode; The control execution module is used to convert the operation strategy into control instructions and output them to the water pump drive module for execution; Mode linkage module, used to establish linkage operation relationships between multiple water pumps and perform mode switching; The recording and optimization module is used to store operation data and optimize mode switching conditions and operation strategy parameters based on historical data.

10. A PLC-based multi-mode intelligent control terminal for water pumps, characterized by: The method comprises at least one processor and a memory in communication with the processor, wherein a computer program is stored in the memory, and when the program is executed by the processor, the processor is enabled to execute the method according to any one of claims 1 to 8.

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