A PLC-based multi-mode intelligent control method for water pump

Abstract

The application belongs to the technical field of intelligent control, and particularly relates to a water pump multi-mode intelligent control method based on PLC. Running 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 mode according to preset trigger conditions through a mode determination module, a running strategy including start-stop sequence, target rotating speed, frequency converter output frequency and pressure set value is generated through a strategy generation module, the strategy is converted into control instructions by a control execution module and output to a water pump driving module, and the mode linkage module is combined to realize linkage operation and mode switching of multiple water pumps; and a record and optimization module stores and analyzes running data, and optimizes mode switching conditions and running strategies. Self-adaptive control and multi-pump collaborative scheduling in multiple modes are realized, and the stability, energy saving property and equipment life of the water supply system are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of intelligent control, and particularly relates to a PLC-based multi-mode intelligent control method for water pumps. BACKGROUND

[0002] At present, water supply systems are widely used in municipal water supply, industrial circulating water, building fire protection, agricultural irrigation and other fields. The water pump, as the core power equipment, directly affects the stability and energy consumption level of the water supply system. The traditional water pump control mode depends on manual operation or single constant pressure or constant flow mode, and meets the water demand through fixed parameter operation. However, in the case of large fluctuation of water consumption or frequent change of operating environment, the fixed control mode is difficult to adapt to the actual working condition in time, and problems such as large pressure fluctuation, high energy consumption and frequent start-stop of water pumps are likely to occur, affecting the service life of the equipment and the economy of the system.

[0003] With the popularization of PLC technology and the improvement of industrial automation level, the water pump control system gradually realizes the integration of multiple operating modes, and realizes the real-time acquisition of parameters such as flow, pressure and liquid level through sensors. However, the existing multi-mode control system is still relatively simple in mode switching strategy, usually relying on the threshold triggering of a single parameter, lacking dynamic analysis and optimization of the comprehensive state of multiple parameters. At the same time, when multiple water pumps are operated in linkage, the existing system is insufficient in coordinating the operating state of each pump, which is likely to lead to uneven load distribution, response delay or pressure mutation in the switching process.

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

[0005] In view of the above problems, the purpose of the present application is to provide a PLC-based multi-mode intelligent control method for water pumps, comprising the following steps:

[0006] S1, running data acquisition and input processing: set multiple running monitoring points, and acquire running parameters in real time through flow sensors, pressure sensors and liquid level sensors;

[0007] S2, control mode selection and condition determination: based on the running parameters, 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 running parameters with the trigger conditions of each mode to determine the target control mode;

[0008] S3, running strategy generation and parameter setting: generating a running strategy from a strategy template according to a target control mode, the running strategy including water pump start-stop sequence, target rotating speed, frequency converter output frequency and pressure set value;

[0009] S4, execution control instruction and dynamic adjustment: converting the running strategy into PLC executable control instructions, outputting to the water pump driving module for execution, and dynamically adjusting the output frequency, start-stop state and number of parallel water pumps based on real-time collected running parameters;

[0010] S5, mode switching and linkage control: when the running condition changes by more than a set threshold, automatically switching to other adaptive modes according to priority rules, and establishing linkage running relationship among multiple water pumps;

[0011] S6, running state recording and optimization update: recording running data, energy consumption indicators and fault alarm information under each mode, generating a historical running record table, and optimizing mode switching conditions and running strategy parameters based on the historical data.

[0012] As a preferred technical solution, in step S2, the triggering conditions of the control mode include at least one of the flow threshold, the pressure threshold, the liquid level height threshold and the equipment running time threshold.

[0013] As a preferred technical solution, in the case of meeting multiple control mode triggering conditions, the target control mode is selected according to 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; the fourth priority is the energy saving optimization mode.

[0014] As a preferred technical solution, step S4 includes:

[0015] S4-1, output start-stop control signal: sending a start or stop instruction to the water pump driving module according to the running strategy;

[0016] S4-2, output frequency control signal: adjusting the frequency converter output frequency according to the deviation of real-time pressure or flow from the set value;

[0017] S4-3, execute pump group switching operation: when the running condition meets the preset switching standard, switch the working state of the running pump and the standby pump.

[0018] As a preferred technical solution, in S4-3, the preset switching standard includes any one or more of cumulative running time, running temperature rise, vibration amplitude and energy efficiency ratio change.

[0019] As a preferred technical solution, in step S5, the priority rule method includes:

[0020] S5-1, global working condition matrix generation: when mode switching is triggered, a multi-dimensional working condition matrix is constructed with each water pump as a row and instantaneous flow, outlet pressure, input power, cumulative running time, temperature rise, vibration amplitude and frequency set value as columns. The cumulative parameters and amplitude parameters are respectively subjected to interval standardization and zero mean standardization to obtain a standardized working condition matrix;

[0021] S5-2, window statistics and derived index calculation: in the fixed length sampling window of PLC, the mean, range and variance of each column of the standardized working condition matrix are calculated in turn to form a statistical matrix; at the same time, by applying a frequency perturbation to the target water pump channel, the derived parameters are measured, including: pressure rise speed, flow recovery speed and unit frequency energy consumption change rate, the derived parameters and the standardized working condition matrix are combined to form an extended working condition feature matrix;

[0022] S5-3, candidate pump set screening: set pump set feasibility criteria, including:

[0023] T1: form a safety performance judgment condition with a safety threshold, including vibration not exceeding a set value, temperature rise not exceeding a set value, frequency not exceeding a set upper limit;

[0024] T2: form a steady-state performance judgment condition with a steady-state performance threshold, including pressure recovery time not exceeding a set value, flow stabilization time not exceeding a set value, energy consumption change rate not exceeding a set value;

[0025] Compare the pump set feasibility criteria with the extended working condition feature matrix row by row to obtain a feasible water pump set, and aggregate the parameters of the pump set combination in the feasible set to generate a combination feature matrix;

[0026] S5-4, preferred pump set determination: in the combination feature matrix, the pressure recovery time, flow stabilization time, energy consumption change rate and new start-stop number are taken as optimization objectives to determine a Pareto optimal set, and in the set, the new start-stop number, pressure recovery time and energy consumption change rate are sequentially minimized in priority order to select a unique pump set combination as the current running combination;

[0027] S5-5, hysteresis and backtracking control: after switching to the new combination, if the outlet pressure drop speed or flow drop speed is detected to exceed the set limit value within one PLC scanning period, the running combination before switching is returned to, and a symmetrical hysteresis interval is set on both sides of the trigger threshold, and the matrix is updated only outside the hysteresis interval.

[0028] As a preferred technical solution, in step S6, the historical running record table is stored in the form of a structured data table, including timestamp, running mode number, energy consumption value, output frequency, flow value and pressure value.

[0029] As a preferred technical solution, the optimization update of the mode switching condition is implemented based on a weighting algorithm, and the weighting algorithm calculates a comprehensive score according to an energy consumption weight, a water supply stability weight and a device health state weight.

[0030] The application also provides a PLC-based multi-mode intelligent control system for water pumps, which is used to implement the method and comprises:

[0031] a data acquisition module configured to acquire water pump operation parameters and water supply system state parameters and generate first data information;

[0032] a mode determination module configured to determine and select a target control mode according to the first data information;

[0033] a strategy generation module configured to generate an operation strategy matched with the target control mode;

[0034] a control execution module configured to convert the operation strategy into control instructions and output the control instructions to a water pump driving module for execution;

[0035] a mode linkage module configured to establish a linkage operation relationship among multiple water pumps and perform mode switching;

[0036] a record and optimization module configured to store operation data and optimize mode switching conditions and operation strategy parameters based on historical data.

[0037] The application also provides a PLC-based multi-mode intelligent control terminal for water pumps, which comprises at least one processor and a memory in communication connection with the processor, and the memory stores a computer program, and when the program is executed by the processor, the processor can execute the method.

[0038] Advantages:

[0039] By introducing a multi-mode operation and real-time working condition matrix scheduling algorithm into a PLC control system, the application realizes fine management of water pump operation states. Compared with a conventional method of switching modes depending on a single parameter threshold, the application can perform standardized processing and window statistical analysis on multiple parameters such as flow, pressure, liquid level, operation duration, temperature rise and vibration amplitude, and obtain a dynamic response index in combination with a frequency perturbation mode, so that multiple conditions are comprehensively determined when switching modes and selecting pump groups, and the accuracy and adaptability of switching are significantly improved.

[0040] In the cooperative operation of multiple water pumps, the application effectively avoids pressure fluctuation and unstable flow caused by improper switching by a dual screening mechanism of safety performance and steady-state performance, and balances pressure recovery time, flow stability time, energy consumption change rate and the number of newly started and stopped times by using a Pareto optimization method, so that water supply stability and energy saving effects are considered.

[0041] In addition, the application provides a hysteresis and backtracking mechanism. If rapid deterioration of key operating parameters is detected after switching, the stable combination can be immediately returned to prevent frequent switching from causing mechanical wear and system impact, prolonging the service life of the equipment and reducing maintenance costs, thereby improving the reliability, economy and intelligence level of the water supply system as a whole. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 A flowchart of the method of the application is shown.

[0043] Figure 2 A schematic diagram of the system structure of the application is shown. DETAILED DESCRIPTION

[0044] In order to deepen the understanding of the application, the application will be further described below in conjunction with the embodiments, which are only used to explain the application and do not constitute a limitation on the scope of protection of the application.

[0045] Embodiment one

[0046] According to Figure 1 The embodiment provides a PLC-based multi-mode intelligent control method for water pumps, which is suitable for municipal water supply, industrial circulating water, building fire protection, agricultural irrigation and other water supply system scenarios, and can realize multi-mode operation, intelligent switching and multi-pump collaborative scheduling of water pumps under different working conditions, thereby balancing water supply stability, energy consumption optimization and equipment life extension.

[0047] S1, running data acquisition and input processing:

[0048] In the PLC control system, according to the structure and water demand of the water supply system, a plurality of running monitoring points are set at key nodes of the pipe network, the pump house outlet main pipe and the water pump outlet.

[0049] Each monitoring point is equipped with a flow sensor, a pressure sensor and a liquid level sensor, wherein the flow sensor is used to measure the instantaneous flow, 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.

[0050] The PLC collects operating parameters through a high-speed data acquisition module at a period of seconds or less, and performs data preprocessing after collection, including signal filtering, outlier rejection and data standardization, to ensure that the data sent to the subsequent control logic has stability and accuracy. The processed operating parameters are converted into first data information in a unified format, providing a data basis for mode determination.

[0051] S2, control mode selection and condition determination:

[0052] The PLC has a preset control mode library inside, including constant pressure water supply mode, constant flow water supply mode, energy saving optimization mode and fault emergency mode.

[0053] The mode selection is determined according to the matching degree of the first data information and the trigger conditions of each mode. The trigger conditions of each mode are composed of multiple-dimensional operating parameters, including one or more of flow threshold, pressure threshold, liquid level height threshold and equipment running time threshold.

[0054] When the trigger conditions of multiple modes are met, the selection is made according to the priority rules: the first priority is the fault emergency mode, which is used to deal with emergency situations such as sensor failure, pump body abnormal vibration, outlet pressure sharp drop, etc.; 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 stable flow; the fourth priority is the energy saving optimization mode, which reduces energy consumption on the premise of meeting water supply demand.

[0055] The PLC performs mode determination logic in each loop scan to realize real-time switching condition monitoring.

[0056] S3, operation strategy generation and parameter setting:

[0057] Once the target control mode is determined, the PLC generates an operation strategy according to the corresponding strategy template. The operation strategy includes water pump start-stop sequence (such as multiple pump alternating start-stop or stepwise start-stop), target speed, frequency converter output frequency, pressure set value, etc.

[0058] For the constant pressure water supply mode, the strategy template will take the pressure set value as the main control target and adjust the output frequency through closed-loop PID control;

[0059] For the constant flow mode, the flow set value is given priority; in the energy saving optimization mode, the number of working pumps and the frequency will be dynamically adjusted according to real-time demand to try to make the pump set run in the high efficiency interval;

[0060] In the fault emergency mode, the faulty pump will be immediately turned off and the standby pump will be switched on to ensure uninterrupted water supply.

[0061] The PLC will make corrections based on real-time operating parameters when generating the strategy, such as correcting the target pressure according to the liquid level change to adapt to transient demand changes.

[0062] S4, execute control instructions and dynamic adjustment:

[0063] 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:

[0064] S4-1 Output start-stop control signal: send start or stop signal to target water pump driving module according to start-stop sequence in strategy, realize water pump according to plan put into or exit operation.

[0065] S4-2 Output frequency control signal: according to the deviation of real-time pressure or flow and set value, adjust the output frequency of frequency converter through analog quantity or communication interface, ensure that the running parameters fluctuate within the allowable range.

[0066] S4-3 Execute pump group switching operation: when the running condition reaches the preset switching standard (including cumulative running time, temperature rise, vibration amplitude or energy efficiency ratio change and other indicators), PLC executes pump group switching, switches the running pump to standby pump, ensures balanced use of equipment and reduces the risk of single pump fatigue operation.

[0067] In the dynamic adjustment process, PLC will monitor the execution effect in real time, if it is found that the adjusted parameter does not reach the expectation, the control instruction will be continuously corrected in the next scanning period, forming a closed loop regulation.

[0068] S5, mode switching and linkage control:

[0069] When the running condition changes more than the set threshold, PLC automatically switches to other adaptive mode according to priority rules, and establishes linkage operation relationship between multiple water pumps. In order to realize efficient switching and stable linkage, this embodiment adopts real-time working condition matrix scheduling algorithm:

[0070] S5-1 Global working condition matrix generation: when mode switching is triggered, a multi-dimensional working condition matrix is constructed with each water pump as a row, instantaneous flow, outlet pressure, input power, cumulative running time, temperature rise, vibration amplitude and frequency set value as columns, interval standardization and zero mean standardization are performed on different types of parameters respectively, and the standardized working condition matrix is obtained.

[0071] S5-2 Window statistics and derived index calculation: in a fixed sampling window, the mean, range and variance of each column of the standardized working condition matrix are calculated to form a statistical matrix; and a small amplitude frequency perturbation is applied to the target pump channel, the derived parameters including pressure rise speed, flow recovery speed and unit frequency energy consumption change rate are measured, and they are combined with the statistical matrix to form an expanded working condition feature matrix.

[0072] S5-3 Candidate pump group screening: according to the pump group feasibility criterion for screening. The safety performance judgment conditions include that vibration, temperature rise, frequency, etc. do not exceed the set threshold; the steady-state performance judgment conditions include that pressure recovery time, flow stability time, energy consumption change rate, etc. do not exceed the set threshold. Apply the criterion to the expanded matrix row by row to obtain the feasible water pump set, and aggregate the combined parameters to form a combined feature matrix.

[0073] S5-4 Preferred pump group determination: In the combined feature matrix, take the pressure recovery time, flow stability time, energy consumption change rate and new start-stop number as the optimization target, determine the Pareto optimal set, and minimize the new start-stop number, pressure recovery time and energy consumption change rate in turn according to the priority, and select the unique pump group combination as the current running combination.

[0074] S5-5 Hysteresis and backtracking control: After switching to the new combination, if the outlet pressure or flow rate decreases at a speed exceeding the limit threshold within one PLC scanning period, immediately revert to the running combination before switching, and set a symmetrical hysteresis interval on both sides of the threshold to prevent frequent switching. Matrix updates are only performed outside the hysteresis interval.

[0075] S6, running state recording and optimization update:

[0076] The PLC records the running data, energy consumption indicators and fault alarm information in each mode in real time during operation, and stores them as a structured data table, including timestamp, running mode number, energy consumption value, output frequency, flow value, pressure value, etc. fields. Periodically import historical data into the optimization algorithm, calculate the comprehensive score according to the energy consumption weight, water supply stability weight and device health state weight, and optimize the mode switching conditions and running strategy parameters. The updated parameters can be directly written into the PLC program to improve the adaptive control capability.

[0077] Example Two

[0078] As shown in Figure 2 , the present embodiment provides a PLC-based multi-mode intelligent control system for water pumps, which can real-time collect the running state of water pumps and water supply systems, combine with multi-mode control strategy to realize mode determination, running strategy generation, control instruction execution and multi-pump collaborative linkage, and optimize the strategy based on historical data in long-term operation, thereby ensuring water supply stability while reducing energy consumption and prolonging equipment life.

[0079] The system is particularly suitable for municipal water supply, industrial circulating water, building fire protection, agricultural irrigation and other scenarios that require multiple water pumps to operate collaboratively.

[0080] The system includes a data acquisition module, a mode determination module, a strategy generation module, a control execution module, a mode linkage module, and a recording and optimization module. The structure and function of each module are as follows.

[0081] 1. Data acquisition module:

[0082] The data acquisition module is used to obtain water pump running parameters and water supply system state parameters, and generate first data information, which is the basic data source of the system.

[0083] Hardware components: including flow sensors, pressure sensors, liquid level sensors, temperature sensors, vibration sensors, etc., and signal conditioning circuits connected to PLC input ports or acquisition modules.

[0084] Flow sensors are installed at the outlets of each water pump or at key locations in the pipe network. Pressure sensors are installed at the pump outlet pipe section and the end of the pipe network. Liquid level sensors are installed in water storage tanks or elevated water tanks. Temperature and vibration sensors are installed in water pump bearings or motor housings.

[0085] Data acquisition method: using PLC high-speed acquisition card or remote I / O module, with millisecond or second level sampling period for continuous data acquisition. To avoid noise interference, the acquisition module performs signal filtering and amplitude stabilization processing before the data enters the PLC.

[0086] Data preprocessing: including outlier rejection (such as rejecting instantaneous mutation values), signal debouncing, data unit unification and standardization processing, to ensure the comparability of different types of parameters in subsequent judgment.

[0087] Data encapsulation and output: encapsulate each sensor data into first data information according to the predefined data structure, store it in the real-time data area of the PLC memory, and transmit it to the mode judgment module regularly.

[0088] 2. Mode judgment module:

[0089] The mode judgment module is used to determine and select the target control mode based on the first data information, directly determining the type of water pump operation strategy.

[0090] Mode library composition: the system has four built-in operation modes: constant pressure water supply mode, constant flow water supply mode, energy saving optimization mode and fault emergency mode.

[0091] Trigger condition definition: each mode corresponds to a set of trigger conditions, including one or more of flow threshold, pressure threshold, liquid level height threshold and device running time threshold. For example, the trigger condition for constant pressure water supply mode is that the pipe network pressure is lower than the set lower limit and the liquid level is higher than the safety height; the trigger condition for energy saving optimization mode is that the pressure and flow are within the set range and the current energy efficiency ratio is lower than the energy saving reference value.

[0092] Multi-mode conflict processing: when multiple mode trigger conditions are met at the same time, the system decides according to the priority order, with the priority order being: fault emergency mode, constant pressure water supply mode, constant flow water supply mode, energy saving optimization mode.

[0093] Logic implementation: in the PLC program, the first data information is compared with the trigger conditions of each mode in real time in a loop scanning manner, and the priority rule is combined to output a unique target mode signal to the strategy generation module in a single scanning period.

[0094] 3. Strategy generation module:

[0095] The strategy generation module is used to generate a running strategy that matches the target control mode, which is an intermediate layer between mode determination and execution control.

[0096] Strategy template library: A strategy template is pre-configured for each mode, including parameters such as water pump start-stop sequence, target speed, frequency converter output frequency, pressure set value, flow set value, and pump group switching interval.

[0097] Parameter correction: The strategy generation module corrects the template based on current running parameters. For example, in constant pressure water supply mode, if the liquid level is close to the lower limit, the target pressure is reduced 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 running pumps is reduced and the running pump frequency is increased.

[0098] Output strategy: The corrected strategy includes all necessary execution instruction parameters and is uniformly output to the control execution module. The strategy can be directly issued through the PLC program or communicated with the upper computer after strategy verification.

[0099] 4. Control execution module:

[0100] The control execution module is used to convert the running strategy into executable control instructions and output them to the water pump drive module for execution.

[0101] Start-stop control: The start-stop instructions in the strategy are converted into digital output signals, which are sent to the contactor or soft starter of each water pump through the PLC output port or communication interface, realizing the start and stop of the water pump.

[0102] Frequency control: The target frequency in the strategy is converted into an analog signal or communication parameter, which is sent through the frequency converter control interface to realize the speed regulation of the water pump motor.

[0103] Pump group switching: According to the pump group switching conditions (cumulative running time, running temperature rise, vibration amplitude, energy efficiency ratio change, etc.) set in the strategy, the switching between running pumps and standby pumps is executed when the conditions are met, ensuring balanced use of pump groups.

[0104] Dynamic adjustment: During execution, the control execution module adjusts the frequency, start-stop state, and number of running pumps in real time based on real-time collected running data, forming a closed-loop control to ensure that the strategy target is continuously achieved.

[0105] 5. Mode linkage module:

[0106] The mode linkage module is used to establish a linkage running relationship between multiple water pumps and execute mode switching, ensuring smooth system operation.

[0107] Real-time working condition matrix scheduling: When mode switching is triggered, the mode linkage module constructs a multi-dimensional working condition matrix based on instantaneous flow, outlet pressure, input power, runtime, temperature rise, vibration amplitude and frequency set values, and performs standardization and statistical analysis.

[0108] Candidate pump group screening: According to the safety performance judgment conditions (vibration, temperature rise, frequency do not exceed the threshold value) and the steady-state performance judgment conditions (pressure recovery time, flow stability time, energy consumption change rate do not exceed the threshold value) to screen feasible pump group combinations.

[0109] Preferred pump group determination: Among the feasible combinations, the pressure recovery time, flow stability time, energy consumption change rate and new start-stop times are optimized, and the current best combination is selected using the Pareto optimization principle.

[0110] Hysteresis and backtracking mechanism: If the pressure or flow rate decreases at a rate exceeding the limit threshold after switching, immediately revert to the combination before switching, and set a hysteresis interval to prevent frequent switching.

[0111] 6、Recording and optimization module:

[0112] The recording and optimization module is used for long-term storage and analysis of running data to optimize mode switching conditions and running strategies.

[0113] Data recording: The timestamp, running mode number, energy consumption value, output frequency, flow value, pressure value and other information of each running period are recorded in a structured data table.

[0114] Data analysis: Regularly analyze historical data, calculate energy consumption weight, water supply stability weight and equipment health status weight, and form a comprehensive score.

[0115] Parameter optimization: Adjust the mode switching conditions and strategy template parameters according to the score results, such as increasing the switching delay of a certain mode, adjusting the pump group switching interval, and optimizing the frequency set value.

[0116] Optimization result application: The optimized parameters are directly written into the PLC program or strategy template to realize adaptive control in the next running period.

[0117] 7、System integration and running process:

[0118] The modules realize data interaction through the internal data area and communication interface of the PLC: 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 operation strategies to the control execution module; the control execution module drives the water pump and feeds back the execution state to the mode linkage module in real time; the mode linkage module adjusts the pump set operation when detecting the switching condition; and the record 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.

[0119] The basic principles, main features and advantages of the present application are shown and described above. Those skilled in the art should understand that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A PLC-based multi-mode intelligent control method for water pumps, characterized in that, The method comprises the following steps: S1, running data acquisition and input processing: set multiple running monitoring points, and collect running parameters in real time through flow sensors, pressure sensors and liquid level sensors; S2, control mode selection and condition determination: based on the running parameters, call a 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 running parameters with the triggering conditions of each mode to determine the target control mode; The triggering conditions of the control mode include at least one of the flow threshold, the pressure threshold, the liquid level height threshold and the equipment running time threshold; in the case of meeting the triggering conditions of multiple control modes, the target control mode is selected according to 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; the fourth priority is the energy saving optimization mode; S3, running strategy generation and parameter setting: generate a running strategy from a strategy template according to the target control mode, the running strategy including water pump start-stop sequence, target rotating speed, frequency converter output frequency and pressure set value; S4, executing control instructions and dynamic adjustment: convert the running strategy into PLC executable control instructions, output to the water pump driving module for execution, and dynamically adjust the output frequency, start-stop state and number of parallel water pumps based on the real-time collected running parameters; S5, mode switching and linkage control: when the running conditions change by more than a set threshold, automatically switch to other adaptive modes according to the priority rules, and establish a linkage running relationship between multiple water pumps; S6, running state recording and optimization updating: record the running data, energy consumption indicators and fault alarm information under each mode, generate a historical running record table, and optimize the mode switching conditions and running strategy parameters based on the historical data.

2. The PLC-based multi-mode intelligent control method of a water pump according to claim 1, characterized in that: Step S4 comprises: S4-1, output start-stop control signal: send a start or stop instruction to the water pump driving module according to the running strategy; S4-2, output frequency control signal: adjust the frequency converter output frequency according to the deviation of real-time pressure or flow from the set value; S4-3, execute pump group switching operation: when the running conditions meet the preset switching criteria, switch the working states of the running pump and the standby pump.

3. The method according to claim 2, wherein the method is characterized in that: In S4-3, the preset switching criteria include any one or more of cumulative running time, running temperature rise, vibration amplitude and energy efficiency ratio change.

4. The method according to claim 3, characterized in that: In step S5, the priority rules include: S5-1, global working condition matrix generation: when the mode switching is triggered, a multi-dimensional working condition matrix is constructed with each water pump as a row and instantaneous flow, outlet pressure, input power, cumulative running time, temperature rise, vibration amplitude and frequency set value as columns; the cumulative parameters and amplitude parameters are respectively processed by interval standardization and zero mean standardization to obtain a standardized working condition matrix; S5-2, window statistics and derived index calculation: in the PLC fixed length sampling window, the mean, range and variance of each column of the standardized working condition matrix are calculated in turn to form a statistical matrix; at the same time, by applying frequency perturbation to the target water pump channel, the derived parameters are measured, including: pressure rise speed, flow recovery speed and unit frequency energy consumption change rate, the derived parameters are combined with the standardized working condition matrix to form an extended working condition characteristic matrix; S5-3, candidate pump set screening: set pump set feasibility criteria, including: T1: form a safety performance judgment condition with a safety threshold, including vibration not exceeding a set value, temperature rise not exceeding a set value, frequency not exceeding a set upper limit; T2: form a steady-state performance judgment condition with a steady-state performance threshold, including pressure recovery time not exceeding a set value, flow stability time not exceeding a set value, energy consumption change rate not exceeding a set value; Compare the pump set feasibility criteria with the extended working condition characteristic matrix row by row to obtain a feasible water pump set, and aggregate the parameters of the pump set combination of the feasible water pump set to generate a combination characteristic matrix; S5-4, preferred pump set determination: in the combination characteristic matrix, the pressure recovery time, flow stability time, energy consumption change rate and new start-stop number are taken as optimization objectives to determine the Pareto optimal set, and in the set, the new start-stop number, pressure recovery time and energy consumption change rate are sequentially minimized in priority order to select a unique pump set combination as the current running combination; S5-5, hysteresis and backtracking control: if the outlet pressure drop speed or flow drop speed exceeds the set limit value within one PLC scanning period after switching to the new combination, the running combination before switching is returned to, and a symmetrical hysteresis interval is set on both sides of the trigger threshold, and the update of the matrix is only carried out outside the hysteresis interval.

5. The method of claim 4, wherein the method is characterized by: In step S6, the historical running record table is stored in the form of a structured data table, including timestamp, running mode number, energy consumption value, output frequency, flow value and pressure value.

6. The method of claim 5, wherein the method is a PLC-based multi-mode intelligent control method for a water pump. The mode switching condition is adjusted based on a weighted algorithm in the optimization update process, and the weighted algorithm calculates a comprehensive score according to the energy consumption weight, water supply stability weight and equipment health state weight.

7. A PLC-based multi-mode intelligent control system for water pumps for implementing the method according to any one of claims 1 to 6, characterized in that, It comprises: a data acquisition module for acquiring water pump running parameters and water supply system state parameters and generating first data information; a mode determination module for determining and selecting a target control mode according to the first data information; a strategy generation module for generating a running strategy matched with the target control mode; a control execution module for converting the running strategy into control instructions and outputting to a water pump driving module for execution; a mode linkage module for establishing a linkage running relationship between multiple water pumps and executing mode switching; a record and optimization module for storing running data and optimizing mode switching conditions and running strategy parameters based on historical data.

8. A PLC-based multi-mode intelligent control terminal for water pumps, characterized in that it comprises: It comprises at least one processor and a memory connected in communication with the processor, and the memory stores a computer program, when the program is executed by the processor, the processor can execute the method of any one of claims 1 to 6.

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