Water pump flow control method and control system

Abstract

A water pump flow control method and control system, the method comprising S1: control system initialization, obtaining a global impedance set through the control system, the global impedance set comprising but not limited to impedance coefficients Z of all branches i , initial pressure Q s , and falling slope K; S2: based on the global impedance set, through the pulse synchronous constant current control method, coordinating the pulse switch timing of all branches, making the whole pipe network system run synchronously in constant current; S3: if the pulse unit at the inlet end of any branch detects that the pressure waveform is continuously abnormal, the fault diagnosis module will send a fault alarm and diagnosis result to the main controller, the main controller isolates the abnormal branch, and re-executes S2. Through the control method and system, the variable frequency water pump can be started at off-peak, avoiding the huge pressure impact caused by the simultaneous start and stop of all valves. Secondly, the variable frequency water pump always works near the resonance point, the output constant flow is stable, the system runs in the "resonance" state, and the irrigation is more stable.

Description

Technical Field

[0001] This invention relates to the field of water pumps, and in particular to a method and control system for controlling water pump flow. Background Technology

[0002] Precision irrigation is a modern agricultural technology that uses intelligent methods to precisely control the amount and timing of irrigation water based on data such as crop water requirements, soil moisture, and weather conditions. In this system, controlling the water pump flow rate is one of the core elements for achieving precision irrigation, directly affecting irrigation efficiency, water resource utilization, and crop growth quality.

[0003] However, in existing traditional systems, when multiple branch valves start and stop simultaneously or asynchronously, the water hammer effect and impedance differences cause drastic fluctuations in the pipeline pressure. This results in uneven flow, with branches closer to the pump experiencing excessive flow while distant branches experience insufficient flow, severely impacting irrigation efficiency and even damaging pipelines and equipment. Secondly, to meet the water demand of the most unfavorable branch (with the highest impedance and furthest distance), the pump typically needs to maintain a high speed, leading to significant energy waste while other branches are operating, resulting in low overall system energy efficiency. Furthermore, traditional centralized control systems have weak detection capabilities for faults in individual branches (such as blockages or leaks), leading to long fault detection and handling cycles, affecting the overall reliability of the system and the continuity of irrigation operations. Summary of the Invention

[0004] To address the above problems, the present invention adopts the following technical solution.

[0005] A method for controlling the flow rate of a water pump includes the following steps:

[0006] S1: Control system initialization. The global impedance set is obtained through the control system. The global impedance set includes, but is not limited to, the impedance coefficients Z of all branches. i Initial pressure Q s and the descending slope K;

[0007] S2: Based on the global impedance set, the pulse switching timing of all branches is coordinated through the pulse synchronous constant current control method to enable the entire pipeline system to operate synchronously with constant current.

[0008] S3: If the pulse unit at the inlet of any branch detects a continuous abnormal pressure waveform, the fault diagnosis module will send a fault alarm and diagnosis results to the main controller. The main controller will isolate the abnormal branch and re-execute S2.

[0009] The control system has a preset update time, which allows the control system to re-initialize at regular intervals, updating only the descent slope K and optimizing the global impedance set.

[0010] Preferably, the specific steps for obtaining the global impedance include:

[0011] S100: Variable frequency water pump operates at a constant speed N b During operation, the main controller commands all pulse units to completely shut down, and in the off state, acquires the initial pressure P from the first pressure sensor. b ;

[0012] S101: The main controller controls each branch in a preset sequence, fully opening the two-way solenoid valve of the currently controlled branch while keeping the other branches closed. The initial pressure P is recorded during this process. b Decreasing steady-state value P w And the descent slope K, and at the same time obtain the initial flow Q of all branches at this time. s ;

[0013] S102: Each microprocessor calculates the impedance coefficient Z of its branch using the impedance coefficient calculation formula. i impedance coefficient Z i Essentially, it reflects the flow capacity of the branch;

[0014] S103: Impedance coefficient Z based on all branches i descent slope K and initial flow rate Q s The global impedance set is obtained and stored locally by the main controller.

[0015] Preferably, the initial flow Q of each branch is... s The mechanical water impeller was measured and found to be located within the pulse unit and also connected to the microprocessor signal.

[0016] Preferably, the specific steps of the pulse synchronization constant current control method include:

[0017] S200: The main controller obtains the initial value F of the pulse frequency based on irrigation requirements and the global impedance set using the pulse frequency calculation formula. S The main controller synchronizes the clock signal and the initial value F of the pulse frequency to all pulse units. S and duty cycle D b ;

[0018] S201: After receiving the instruction, each pulse unit determines the impedance coefficient Z of each microprocessor. i Calculate the relative offset Φ i Each pulse unit at its specific phase point, with a duty cycle D b Based on this, pulse operation begins;

[0019] S202: Each pulse unit calculates the local synchronization error by comparing the pressure pulse waveform from the local second pressure sensor with the expected waveform broadcast by the main controller. Each microprocessor can autonomously adjust its own duty cycle D.b In order to minimize its own synchronization error;

[0020] S203: The main controller monitors the waveform of the first pressure sensor. When all pulse units are well synchronized, the waveform of the first pressure sensor will exhibit a stable periodicity. The main controller can also fine-tune the initial value F of the pulse frequency through the microprocessor. S The goal is to find the resonant frequency point that makes the waveform of the first pressure sensor stable and has a small variance.

[0021] S204: Under the combined action of steps 202 and 203, the waveforms of the first pressure sensor and the second pressure sensor are rapidly converged and stabilized in a resonance state. In this state, the total output flow of the control system remains constant.

[0022] Preferably, the formula for calculating the pulse frequency is:

[0023]

[0024] in: This represents the pulse frequency coefficient. To set the total flow rate, m³ / s; The equivalent cross-sectional area is in m², and the corresponding annular pipe cross-sectional area is taken.

[0025] Preferably, the duty cycle D b The calculation formula is:

[0026]

[0027] in: Q represents the total number of currently active, normal branches. max Assuming the valve on the i-th branch is fully open and the system pressure is P b At that time, the maximum flow rate that this branch can handle is m³ / h.

[0028] Preferably, the present invention also provides a water pump flow control system applied to the aforementioned water pump flow control method. The water pump flow control system includes: a variable frequency water pump, the outlet of which is equipped with a first pressure sensor and a first pressure relief valve, and the inlet of which is connected to a water source; a main pipeline connected to the outlet of the variable frequency water pump, the main pipeline being connected to one or more annular pipelines; branch lines, from which multiple branch lines for irrigation are connected in parallel, each branch line being equipped with a pulse unit; and a main controller, which is signal-connected to the variable frequency water pump, the first pressure sensor, the first pressure relief valve, and all pulse units.

[0029] Preferably, the pulse unit includes a two-way solenoid valve, a microprocessor, a second pressure sensor, and a communication unit. The two-way solenoid valve is used to control the opening and closing of each branch. The microprocessor is used to receive signals from the main controller and execute processing instructions. The second pressure sensor is used to monitor the pressure pulse at the inlet of the corresponding branch. The communication unit is used to receive or send signals.

[0030] Preferably, the pulse unit further includes a self-learning module and a fault diagnosis module. The self-learning module is used to update the descent slope K and operates only in self-learning mode. The fault diagnosis module is used to monitor the pressure fluctuation of the second pressure sensor and feed back fault information to the main controller.

[0031] Preferably, the present invention also provides a water pump flow control device, wherein the water pump flow control device is equipped with the water pump flow control system described above.

[0032] The beneficial effects of this invention are as follows:

[0033] First, the flow control method provided by this invention can transform the physical pipeline system into a precise digital model, enabling the control system to control the characteristics of each branch by using a "global impedance set" to address the inherent characteristics of the system caused by installation, wear, blockage, etc., rather than relying on ideal design parameters, thus making the control more realistic.

[0034] Secondly, this invention enables staggered operation, fundamentally avoiding the huge pressure shock (water hammer) caused by the simultaneous start and stop of all valves, thus protecting pipelines and equipment. Furthermore, it ensures that the variable frequency water pump always operates near its high efficiency point, with stable output flow. The system operates in a "resonance" state, with small pressure fluctuations, low resistance loss, and the lowest energy consumption of the variable frequency water pump, meeting the needs of precise irrigation.

[0035] Third, the system provided by this invention connects the main pipelines to form a closed loop, constituting one or more pressure balance loops. When any branch pulse is activated, water flow can simultaneously replenish from two directions, instantly balancing the pressure fluctuations within the pipeline. This provides an extremely stable pressure platform for subsequent precise synchronous control. Furthermore, the first and second pressure sensors form a dual-layer pressure sensing network, and through a self-learning module, long-term self-adaptation is achieved. Ultimately, a stable, energy-efficient, reliable, intelligent, and virtually maintenance-free high-performance irrigation control system is successfully constructed. Attached Figure Description

[0036] Figure 1 This is a schematic flowchart of the method of the present invention;

[0037] Figure 2 This is a detailed flowchart of step S1;

[0038] Figure 3This is a detailed flowchart of step S2;

[0039] Figure 4 This is a schematic diagram of the system layout of the present invention;

[0040] Figure 5 This is a schematic diagram of another system layout according to the present invention;

[0041] Figure 6 This is a schematic diagram of the system components of the invention;

[0042] In the diagram: 1. Variable frequency water pump; 2. Main pipeline; 3. Ring pipeline; 4. Branch pipeline; 5. Pulse unit; 6. First sensor; 7. First pressure relief valve; 8. Main controller; 50. Two-way solenoid valve; 51. Microprocessor; 52. Second pressure sensor; 53. Communication unit; 54. Self-learning module; and 55. Fault diagnosis module. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0044] In the description of this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0045] Example 1:

[0046] Please see Figure 1 A method for controlling the flow rate of a water pump, comprising the following steps:

[0047] S1: Control system initialization. The global impedance set is obtained through the control system. The global impedance set includes, but is not limited to, the impedance coefficients Z of all branches. i Initial pressure Q s and the descending slope K;

[0048] S2: Based on the global impedance set, the pulse switching timing of all branches is coordinated through the pulse synchronous constant current control method to enable the entire pipeline system to operate synchronously with constant current.

[0049] S3: If the pulse unit at the inlet of any branch detects a continuous abnormal pressure waveform, the fault diagnosis module will send a fault alarm and diagnosis results to the main controller. The main controller will isolate the abnormal branch and re-execute S2.

[0050] The control system has a preset update time, which allows the control system to re-initialize at regular intervals, updating only the descent slope K and optimizing the global impedance set.

[0051] Through the above technical solution, step S1 first designs the control system layout according to the actual situation, and installs the variable frequency water pump 1, main pipeline 2, ring pipeline 3, each branch 4, and pulse unit 5 (including two-way solenoid valve 50, microprocessor 51, and second pressure sensor 52, etc.) according to the design scheme, and ensures that all equipment communicates normally with the main controller 8. Then, initialization is performed. The main controller 8 and all pulse units 5 are powered on, perform self-test, load default parameters, and enter the ready state. The global impedance set is obtained through the control system. The global impedance set includes, but is not limited to, the impedance coefficient Z of all branches. i Initial pressure Q s And the descent slope K; S2 is the core of intelligent system operation based on global impedance set data, which fundamentally avoids the huge pressure shock (water hammer) caused by the simultaneous start and stop of all valves, protects the pipeline and equipment, and ensures that the variable frequency water pump 1 always works near the resonance point, outputting a constant and stable flow rate; S3 monitors the pressure waveform of the pulse unit 5 on each branch 4 and isolates abnormal branches 4, as follows: First, the fault diagnosis module 55 will compare the real-time second pressure sensor 52 data with a expected pressure waveform template based on historical data in each pulse cycle, and execute different detection logic. Common fault types include blockage fault, leakage / pipe burst fault and synchronization misalignment fault. Different trigger conditions and diagnostic rules are set for each fault type.

[0052] Take a blockage fault as an example:

[0053] The trigger condition is that after the two-way solenoid valve 50 issues the valve opening command, the pressure of the second pressure sensor 52 does not drop as expected. The fault diagnosis module 55 will calculate the actual pressure drop slope K and the absolute value of the pressure drop within a time window after the valve opens, such as within 500ms, and compare them synchronously with the preset pressure drop slope threshold and pressure drop absolute value threshold. When the actual pressure drop slope < the pressure drop slope threshold and the actual pressure drop absolute value < the pressure drop absolute value threshold, it is determined to be a blockage. The preset pressure drop slope threshold and pressure drop absolute value threshold are the normal values ​​measured by the control system in the self-learning mode and multiplied by a safety factor.

[0054] Taking a leak / pipe burst as an example:

[0055] The trigger condition is that after the two-way solenoid valve 50 issues the valve opening command, the pressure of the second pressure sensor 52 does not rise as expected. The fault diagnosis module 55 will calculate the actual pressure rise slope and the pressure stability value within a time window after the valve closes, such as within 100ms, and compare them synchronously with the preset pressure rise slope and pressure stability value thresholds. When the actual pressure rise slope is less than the pressure rise slope threshold, it is determined to be a leak; when the actual pressure stability value is less than the pressure stability threshold, it is determined to be a pipe rupture. The thresholds are obtained by multiplying the normal value measured by the system in self-learning mode by a safety factor.

[0056] After receiving feedback from the fault diagnosis module 55, the main controller 8 will send a command to the microprocessor 51 to isolate it (force the two-way solenoid valve 50 to close and remove it from the list of active branches 4), which realizes rapid fault detection, location and isolation, and avoids the failure of a single branch 4 from causing the entire system to be paralyzed. It mainly enables the control system to keep up with the times and automatically adapt to the slow-acting changes in system characteristics such as pipe scaling, filter blockage and valve aging, and always maintain the best control state.

[0057] See Figure 2 The specific steps for obtaining the global impedance include:

[0058] S100: Variable frequency water pump 1 operates at a constant speed N b During operation, the main controller 8 commands all pulse units 5 to completely shut down, and in the off state, acquires the initial pressure P from the first pressure sensor 6. b At this time, the variable frequency water pump 1 operates at a preset constant speed N. b With all branch lines 4 closed, the water output from variable frequency pump 1 has nowhere to go, and the pressure from the first pressure sensor 6 on the main channel 2 will rapidly rise and stabilize at a certain value. This stable value is recorded as the initial pressure P. b P b This represents the maximum static pressure that variable frequency water pump 1 can provide at the current speed;

[0059] S101: The main controller 8 controls each branch 4 in a preset sequence, so that the two-way solenoid valve 50 of the currently controlled branch 4 is fully opened, while the other branches 4 remain closed. The initial pressure P is recorded during this process. b Decreasing steady-state value P w And the descent slope K, and at the same time obtain the initial flow Q of all branches 4 at this time. s The main controller 8 sequentially (e.g., starting from a certain branch 4) fully activates the pulse unit 5 of one branch 4, while keeping the other branches 4 closed. At this time, the branch 4 is fully open to release water, and the system pressure will decrease from the initial pressure P. b It drops instantaneously and stabilizes at a lower steady-state pressure P.w This pressure drop process will have a downward slope K. Simultaneously, the mechanical water impeller installed in the pulse unit 5 on branch 4 will measure the initial flow rate Q passing through at this time. s ;

[0060] S102: Each microprocessor 51 calculates the impedance coefficient Z of its branch 4 using the impedance coefficient calculation formula. i impedance coefficient Z i Essentially, it reflects the current-carrying capacity of branch 4; for example, a microprocessor 51 of branch 4 uses a formula to calculate its impedance coefficient Z. i The formula for calculating its impedance is:

[0061]

[0062] This formula quantifies the relationship between the "driving force" (pressure) required for water to flow through branch 4 and the resulting flow rate. i A large value indicates poor flow capacity of the branch (long pipe, small diameter, blockage); Z i A smaller value indicates stronger flow capacity;

[0063] S103: Impedance coefficient Z based on all branches 4 i descent slope K and initial flow rate Q s The global impedance set is obtained and stored locally by the main controller 8. By testing all branches 4 one by one, the main controller 8 will collect the Z-scores of all branches. i Q s Data such as K are collected and stored to form a "global impedance set".

[0064] The above technical solution transforms the physical pipeline system into a precise digital model, enabling the control system to better understand the characteristics of each branch 4 through a "global impedance set." This allows the system to control the inherent characteristics caused by installation, wear, blockage, etc., rather than relying on ideal design parameters, making the control more realistic.

[0065] For example:

[0066] A greenhouse irrigation system with four branch lines, such as Figure 4 The system displays 12 branches. A branch can be four branches connected in parallel within a single loop, or one branch can be set on each loop pipe. For example, irrigation branches 1 (tomato), 2 (cucumber), 3 (leafy vegetables), and 4 (seedbed) are four branches. The four longest branches are equipped with additional fine filters. At this time, the main controller 8 controls the variable frequency water pump 1 to start, and all valves are completely closed, including the first pressure relief valve 7 and the two-way solenoid valves 50 of each branch 4. The measured P... bThe pressure is 0.6 MPa. Then, the main controller 8 controls the pulse unit 5 corresponding to section C (branch). The pulse unit 5 monitors that the pressure has stabilized to... The initial flow rate is 0.3 MPa, and the initial flow rate is Q. s If the flow rate is 3.6 m³ / h, then the Z4 of the branch is:

[0067] = =0.083

[0068] Similarly, the Z4 values ​​of other branches were measured, such as Z1=0.025, Z2=0.032, and Z3=0.045.

[0069] The initial flow rate Q of pulse unit 5 s The mechanical water impeller is measured to be located within the pulse unit 5 and is also connected to the microprocessor 51 via signal transmission.

[0070] See Figure 3 The specific steps of the pulse synchronization constant current control method include:

[0071] S200: The main controller 8 obtains the initial value F of the pulse frequency based on irrigation requirements and the global impedance set using the pulse frequency calculation formula. S Then, the main controller 8 synchronizes the clock signal and the initial value of the pulse frequency F to all pulse units 5. S and duty cycle D b Irrigation demand typically refers to the total flow rate demand set by the user. The main controller 8 determines the total required flow rate based on the set parameters. An initial pulse frequency F that ensures stable operation of the control system is obtained through the pulse frequency calculation formula. S And an initial duty cycle D b These parameters, along with a synchronous clock signal, are broadcast to all pulse units 5.

[0072] S201: After receiving the command, each pulse unit 5 does not switch on and off simultaneously. The pulse unit 5 on each branch 4 switches according to its own impedance coefficient Z. i (Possibly Z) i The larger the value, the more the phase lags (the larger the value, the more the phase lags), calculate a relative offset Φ. i This ensures that the activation times of each branch are evenly distributed within one cycle, and then each pulse unit, at its specific phase point, operates with a duty cycle D. b Based on this, pulse operation begins;

[0073] S202: Each pulse unit 5 calculates the local synchronization error by comparing the local pressure pulse waveform with the expected waveform broadcast by the main controller, and each pulse unit 5 autonomously adjusts its own duty cycle D.b To minimize its own synchronization error, each pulse unit 5, during operation, uses its own second pressure sensor 52 to monitor the local actual pressure waveform and compares it with the "expected ideal waveform" broadcast by the main controller 8. If an error exists (such as the pressure dropping more or less than expected after activation), the pulse unit 5 will autonomously fine-tune its duty cycle D. b (Slightly extend or shorten the start time) to eliminate this error and ensure that the traffic is consistent with expectations;

[0074] S203: The main controller 8 monitors the waveform of the first pressure sensor 6. When all pulse units 5 are well synchronized, the waveform of the first pressure sensor 6 will exhibit a stable periodicity. The main controller 8 can also fine-tune the initial value F of the pulse frequency. S Find the resonant frequency point that makes the waveform of the first pressure sensor 6 stable and has a small variance. At this frequency, the pressure fluctuation of the control system is minimized and the working efficiency of the variable frequency water pump 1 is maximized.

[0075] S204: Under the combined action of steps 202 and 203, the waveforms of the first pressure sensor 6 and the second pressure sensor 52 are quickly converged and stabilized in a resonance state. In this state, the total output flow of the control system remains constant. At this time, although each branch 4 is intermittently pulsed with water supply, from the perspective of the variable frequency water pump 1, the total outflow is constant and the pressure fluctuation is minimal.

[0076] Through the above technical solutions, the control system can stagger the start-up times, fundamentally avoiding the huge pressure shock (water hammer) caused by the simultaneous start-up and shutdown of all valves, thus protecting the pipelines and equipment. Secondly, it ensures that the variable frequency water pump 1 always works near the resonance point, with stable output flow. The system operates in a "resonance" state, with small pressure fluctuations, which means less unnecessary resistance loss. The variable frequency water pump 1 has the lowest energy consumption, meeting the needs of precision irrigation.

[0077] The formula for calculating the pulse frequency is:

[0078]

[0079] in: This represents the pulse frequency coefficient. To set the total required flow rate, m³ / s; The equivalent cross-sectional area is in m², and is taken as the cross-sectional area of ​​the corresponding annular pipe.

[0080] The equivalent cross-sectional area is not the sum of the areas of all branches, but rather the cross-sectional area of ​​the corresponding annular pipe 3. It represents the size of the "capacity channel" for water delivery in the corresponding annular pipe 3. Generally determined through preliminary simulations, it represents the reciprocal of the pulse wavelength required to generate a stable pressure wave. This can be understood as follows: water flows at a velocity v in a pipe, and we want the water hammer waves generated within one pulse cycle to effectively superimpose and attenuate within the pipe, rather than interfere with each other. The value is related to the length and material of the branch road, and its range is generally between 0.5 and 2.0.

[0081] The duty cycle D b The calculation formula is:

[0082]

[0083] in: Q represents the total number of currently active, normal branches. max Assuming the valve on the i-th branch is fully open and the system pressure is P b At that time, the maximum flow rate that this branch can handle is m³ / h.

[0084] Duty cycle D b The goal of the calculation is to determine, under ideal conditions, what share of the flow should each branch 4 be allocated if all branches 4 have the same impedance.

[0085] For example:

[0086] See Figure 4 or Figure 5 For example, the currently active pulse unit has 12 branches. Take 12, The "target average flow" for each branch 4. For example, if the total demand is 120 m³ / h and there are 12 branches, then the target flow for each branch 4 is 10 m³ / h. Q max This value is obtained during the global impedance set acquisition process, specifically when the two-way solenoid valve 50 of each pulse unit 5 is fully open. This process not only calculates Z... i Q was also measured. s This Q s It's in P b Q was measured under pressure, therefore it can be considered that... max ≈Q s .

[0087] Overall, exemplary:

[0088] like Figure 4 Assume an irrigation system with a loop pipe and four branches. The user-defined total flow rate is 36 m³ / h (0.01 m³ / s). The loop pipe is a DN80 PE pipe with an inner diameter of 90 mm. Then the equivalent cross-sectional area... =π ≈0.006m², Take 1.2, N is 4, and the initial pressure P of each branch is measured through step S1. b Initial flow Q s They are: Q s1 12 m³ / h, Q s2 15 m³ / h, Q s3 10 m³ / h, Q s4 It is 18 m³ / h.

[0089] Calculate the initial value F of the pulse frequency. S :F S = ≈1.67k≈2.004Hz, the main controller 8 will attempt to start operating at a frequency of approximately 2.004Hz.

[0090] Calculate the duty cycle D b Here, we generally take Q from all branches 4. s The average value is used to represent Q. max That is =13.75 m³ / h, the target average flow rate for each branch 4 is: 36 / 4 = 9 m³ / h, then according to the calculation formula, D b If the value is 0.65, then the main controller 8 will instruct all pulse units 5 to use a 65% duty cycle as their initial switching ratio. That is, after the system starts, the pulse units 5 on each branch 4 will immediately switch according to their own impedance Z. i Calculate the phase shift and begin running at a frequency of 1.9 Hz and a duty cycle of 65%. Then, proceed to steps S2-S3, where the local and global optimization processes will begin fine-tuning D. b and F S Eventually, a resonance point is found, which may stabilize at F. S =2.1 Hz, and the duty cycles of each branch 4 are D respectively. b1 =70%, D b2 =55%,D b3 =80%, D b4 It operates stably at 60% of its capacity.

[0091] Example 2:

[0092] See Figure 4-6A water pump flow control system, applied to the aforementioned water pump flow control method, comprises: a variable frequency water pump 1, the outlet of which is equipped with a first pressure sensor 6 and a first pressure relief valve 7, and the inlet of which is connected to a water source; a main pipeline 2, connected to the outlet of the variable frequency water pump 1, and connected to one or more annular pipelines 3, wherein the annular pipelines 3 may be multiple in parallel; branch lines 4, from which multiple branch lines 4 for irrigation are connected in parallel, each branch line 4 being equipped with a pulse unit 5; and a main controller 8, which is signal-connected to the variable frequency water pump 1, the first sensor 6, the first pressure relief valve 7, and all pulse units 5, wherein the pulse unit 5 is an intelligent terminal that serves as the "brain" (microprocessor 51) and "sensory organ" (second pressure sensor 52) of each branch line 4. This is not only an actuator but also an independent control node.

[0093] The pulse unit 5 includes a two-way solenoid valve 50, a microprocessor 51, a second pressure sensor 52, and a communication unit 53. The two-way solenoid valve 50 is used to control the opening and closing of each branch 4. The microprocessor 51 is used to receive signals from the main controller 8 and execute processing instructions. The second pressure sensor 52 is used to monitor the pressure pulse at the inlet of the corresponding branch 4. The microprocessor 51 can process local pressure data in real time and autonomously fine-tune the switching duty cycle of the two-way solenoid valve 50. The response speed is much higher than the traditional method of uploading data to the main controller and then waiting for instructions. This makes the system extremely strong in resisting interference and maintaining the stability of its own branch flow.

[0094] The pulse unit 5 also includes a self-learning module 54 and a fault diagnosis module 55. The self-learning module 54 is used to update the descent slope K and operates only in self-learning mode. The fault diagnosis module 55 is used to monitor the pressure fluctuations of the second pressure sensor 52 and feed back fault information to the main controller 8, completing the accurate calibration of the impedance of each branch 4. This allows the system to not only adapt to the initial state but also to be updated periodically.

[0095] Through the above technical solution, the main pipeline 2 is connected to the ring pipeline to form a closed loop, constituting one or more pressure balance rings. When any branch 4 pulse is activated, water flow can simultaneously replenish from two directions, instantly balancing the pressure fluctuations within the pipeline. This fundamentally eliminates the drawback of "high pressure at the near end and low pressure at the far end" in traditional branched pipe networks, providing an extremely stable pressure platform for subsequent precise synchronous control, greatly suppressing the water hammer effect. Furthermore, multiple parallel ring pipelines 3 can be divided into multiple independent ring areas for ultra-large irrigation projects, controlled by the same main system, avoiding pressure loss caused by excessively long single-ring pipelines. Secondly, the first pressure sensor 6 (located on the main pipeline 2) acts as the "eye" of the main controller 8, monitoring the overall energy status and health of the control system, and is used to find the resonant frequency that minimizes the energy consumption of the entire system. The second pressure sensor 52 (located on each branch 4) is the "tentacle" of each pulse unit 5, used for monitoring pressure fluctuations in each branch 4, which is the key to achieving branch 4-level intelligence.

[0096] Example 3:

[0097] The present invention also provides a water pump flow control device, wherein the water pump flow control device is equipped with the water pump flow control system described in Embodiment 2 above.

[0098] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for controlling the flow rate of a water pump, characterized in that, Includes the following steps: S1: the control system is initialized, and a global impedance set is obtained by the control system, the global impedance set including impedance coefficients Z of all branches i , initial pressure Q s , and falling slope K; S2: Based on the global impedance set, the pulse switching timing of all branches is coordinated through the pulse synchronous constant current control method to enable the entire pipeline system to operate synchronously with constant current. S3: If the pulse unit at the inlet of any branch detects a continuous abnormal pressure waveform, the fault diagnosis module will send a fault alarm and diagnosis results to the main controller. The main controller will isolate the abnormal branch and re-execute S2. The control system has a preset update time, which allows it to re-initialize, update the descent slope K, and optimize the global impedance set at regular intervals. The specific steps for obtaining the global impedance include: S100: The variable frequency water pump runs at a constant speed N b Operation, the main controller commands all pulse units to be completely closed, and the initial pressure P of the first pressure sensor is obtained in the closed state b ; S101: the main controller controls each branch in a preset order, so that the two-way electromagnetic valve of the current controlled branch is fully opened, and the remaining branches remain closed. This process records the initial pressure P b The steady-state value of the drop P w And the drop slope K, while obtaining the initial flow Q of the fully open branch at this time s ; S102: Each microprocessor calculates the impedance coefficient Z of the branch by using the impedance coefficient calculation formula i , the impedance coefficient Z i Essentially reflects the flow capacity of the branch; S103: Impedance coefficient Z based on all branches i , the falling slope K and the initial flow Q s , get the global impedance set, stored locally by the main controller; the specific steps of the pulse synchronous constant current control method include: S200: The main controller obtains the initial value F of the pulse frequency according to the irrigation requirement and the global impedance set through the pulse frequency calculation formula S S300: The main controller synchronizes the clock signal, the initial value F of the pulse frequency and the duty cycle D to all pulse units S S400: The main controller adjusts the initial value F of the pulse frequency according to the global impedance set and the global impedance feedback value b ​ S201: After receiving the instruction, each microprocessor starts the pulse operation according to its own impedance coefficient Z i Calculate the relative offset Φ i Each pulse unit starts the pulse operation at its corresponding phase point with the duty cycle D b as the reference. S202: Each pulse unit calculates local synchronization error by comparing the local second pressure sensor pressure pulse waveform with the expected waveform broadcast by the master controller, and each microprocessor can autonomously adjust its own duty cycle D b to minimize its own synchronization error; S203: the main controller monitors the first pressure sensor waveform, when all pulse units are synchronized well, the waveform of the first pressure sensor will present stable periodicity, wherein the main controller can also fine-tune the initial value F of the pulse frequency through the microprocessor S , find the resonance frequency point that makes the first pressure sensor waveform stable and the variance small; S204: Under the combined action of steps 202 and 203, the waveforms of the first pressure sensor and the second pressure sensor converge rapidly and stabilize in a resonance state. In this state, the total output flow of the control system remains constant. The formula for calculating the pulse frequency is: Where: k1 is the pulse frequency coefficient; Q t Q is the set total flow, m3 / s; At is the equivalent cross-sectional area, m2, taking the corresponding annular pipe cross-sectional area; The duty cycle D b The calculation formula is: Where: N is the total number of currently active, normal branches; Q max Assuming the valve on the i-th branch is fully open and the system pressure is P b At that time, the maximum flow rate that this branch can handle is m³ / h.

2. The water pump flow control method according to claim 1, characterized in that, The initial flow Q of each branch s The mechanical water impeller was measured and found to be located within the pulse unit and also connected to the microprocessor signal.

3. A water pump flow control system, applied to the water pump flow control method according to any one of claims 1-2, characterized in that, The water pump flow control system includes: a variable frequency water pump, the outlet of which is equipped with a first pressure sensor and a first pressure relief valve, and the inlet of which is connected to a water source; a main pipeline connected to the outlet of the variable frequency water pump, which is connected to one or more ring pipelines; branch lines, from which multiple branch lines for irrigation are connected in parallel, each branch line being equipped with a pulse unit; and a main controller, which is connected to the variable frequency water pump, the first pressure sensor, the first pressure relief valve, and all pulse units.

4. A water pump flow control system according to claim 3, characterized in that, The pulse unit includes a two-way solenoid valve, a microprocessor, a second pressure sensor, and a communication unit. The two-way solenoid valve is used to control the opening and closing of each branch. The microprocessor is used to receive signals from the main controller and execute processing instructions. The second pressure sensor is used to monitor the pressure pulse at the inlet of the corresponding branch. The communication unit is used to receive or send signals.

5. A water pump flow control system according to claim 3, characterized in that, The pulse unit also includes a self-learning module and a fault diagnosis module. The self-learning module is used to update the descent slope K and operates only in self-learning mode. The fault diagnosis module is used to monitor the pressure fluctuation of the second pressure sensor and feed back fault information to the main controller.

6. A water pump flow control device, characterized in that, The water pump flow control device is equipped with a water pump flow control system as described in any one of claims 3-5.

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