Pump station unit coordinated dispatching energy-saving control method based on water plant fluid resistance

Abstract

The application provides a pump station unit cooperative scheduling energy-saving control method based on water plant fluid resistance, relates to the pump station control technical field, and comprises the following steps: extracting the fluid resistance characteristics of a pipeline system, and determining the scheduling priority of each water pump according to the fluid resistance characteristics, the operation condition parameters of the water pump and the efficiency characteristics of the water pump under different instantaneous flow rates; determining the current total load of the pump station unit according to the instantaneous flow rate of the water pump, and determining the load distribution deviation degree of the pump station unit according to the difference degree between the actual load distribution and the target load distribution of the water pump; when the load distribution deviation degree exceeds a preset threshold value, the load of each water pump is cooperatively distributed and the rotating speed of each water pump is synchronously adjusted according to the scheduling priority and the load distribution deviation degree, and the outlet pressure of the water pump is converged to the target pressure value matched with the fluid resistance characteristics. By adopting the scheme of the application, the load dynamic balance control of the pipeline-water pump coupling can be realized, so that the overall energy efficiency of the pump station unit is improved.

Description

Technical Field

[0001] This application relates to the field of pump station control technology, and more specifically, to a method for energy-saving control of pump station units based on the fluid resistance of a water plant through coordinated scheduling. Background Technology

[0002] Pump station unit control mainly relies on constant speed pump valve throttling or efficiency-based frequency conversion regulation, which is a relatively crude operation method. In actual operation, the fluid resistance characteristics of the pipeline system directly determine the nonlinear coupling relationship between flow rate and head, which in turn affects the actual operating point of each pump and the overall energy consumption. Existing control methods usually take the pump's own efficiency as the core basis for load allocation, while ignoring the constraint of fluid resistance on the matching degree between outlet pressure and pipeline demand, resulting in obvious blind spots in coordinated scheduling.

[0003] When the total water supply or pipeline conditions change, allocating load solely based on efficiency can cause significant deviations between the outlet pressure of some pumps and the pipeline demand pressure. Excessive pressure leads to throttling losses, while insufficient pressure results in inefficiency or even cavitation, significantly increasing overall energy consumption. Furthermore, the lack of real-time sensing and quantitative characterization of pipeline resistance characteristics makes it impossible to assess load distribution deviations between different pumps, hindering coordinated regulation and making dynamic equilibrium control difficult. Therefore, achieving dynamic load equilibrium control through pipeline-pump coupling to improve the overall energy efficiency of pumping station units has become a major challenge for the industry. Summary of the Invention

[0004] This application provides a method for coordinated scheduling and energy-saving control of pump station units based on the fluid resistance of water plants, which can realize dynamic load balance control of pipeline-pump coupling, thereby improving the overall energy efficiency of pump station units.

[0005] In a first aspect, this application provides a method for energy-saving control of pump station units based on the fluid resistance of a water plant, comprising the following steps: Monitor the operating parameters of each pump in the pumping station unit, including output power, outlet pressure, instantaneous flow rate and speed; Based on the performance characteristics data of each water pump, its performance characteristics under different instantaneous flow rates are calibrated; Extract the fluid resistance characteristics of the pipeline system, and determine the scheduling priority of each pump based on the fluid resistance characteristics, the current operating parameters of each pump and their corresponding performance characteristics. The current total load of the pumping station units is determined based on the instantaneous flow rate of each pump, and a target load distribution matching the current total load is determined. The load distribution deviation of the pumping station units is determined based on the degree of difference between the actual load distribution of each pump and the target load distribution. When the load distribution deviation exceeds a preset threshold, the load of each water pump is coordinated and redistributed according to the scheduling priority and the load distribution deviation, and their speed is adjusted synchronously until the outlet pressure of each water pump converges to the target pressure value that matches the fluid resistance characteristics.

[0006] In some embodiments, calibrating the performance characteristics of each pump at different instantaneous flow rates based on its performance characteristic data specifically includes: Obtain the flow-efficiency curves of each water pump under standard test conditions, and extract multiple discrete flow points and their corresponding efficiency values ​​from the flow-efficiency curves. The efficiency values ​​of intermediate flow points are supplemented by nonlinear interpolation for the intervals between adjacent discrete flow points, forming an efficiency characteristic mapping table within the continuous flow interval; The performance feature mapping table is determined as the calibrated performance features.

[0007] In some embodiments, obtaining the flow-efficiency curves of each water pump under standard test conditions specifically includes: Drive the water pump to its rated speed and keep it stable. Change the load by adjusting the outlet valve and record the instantaneous flow rate and shaft power at multiple different flow stability points. The actual efficiency at each test point is calculated based on the instantaneous flow rate and shaft power, and the flow-efficiency polynomial curve of the pump at rated speed is obtained by fitting using the least squares method. The polynomial curve is stored as a flow-efficiency curve in the control unit.

[0008] In some embodiments, extracting the fluid resistance characteristics of a pipeline system specifically includes: Collect inlet and outlet pressure difference data of pump station units in multiple stable operating ranges with different total flow rates, and record the corresponding total flow rates simultaneously; Substitute the total flow rate and inlet / outlet pressure difference data of each group into the resistance characteristic function, and determine the comprehensive resistance coefficient of the pipeline system through regression analysis. The comprehensive resistance coefficient is used as a fluid resistance characteristic to characterize the relationship between pressure difference and flow rate in a pipeline system.

[0009] In some embodiments, collecting inlet and outlet pressure difference data of the pump station unit in multiple stable operating ranges with different total flow rates specifically includes: Based on the daily water supply flow rate change curve of the water plant, several typical load periods were selected, and stable differential pressure and flow rate data were continuously collected within a preset time period in each period. The collected differential pressure data is filtered using a moving average to remove abnormal fluctuations. The filtered differential pressure data and the average total flow rate of the corresponding time period are used as a set of effective sample points. At least a preset number of effective sample points under different total flow rates are obtained as input for regression analysis.

[0010] In some embodiments, determining the scheduling priority of each water pump based on the fluid resistance characteristics, the current operating parameters of each pump, and their corresponding performance characteristics specifically includes: Based on the current instantaneous flow rate of each pump, the corresponding current efficiency is queried from the performance characteristics, and the pumps are initially sorted from high to low according to their current efficiency. Based on the fluid resistance characteristics and the current outlet pressure of each pump, calculate the additional energy consumption required for each pump to overcome the current pipeline resistance, and correct the initial ranking based on the additional energy consumption; The scheduling priority of each water pump is determined based on the revised sorting results.

[0011] In some embodiments, determining the current total load of the pumping station units based on the instantaneous flow rate of each pump, and determining the target load distribution that matches the current total load specifically includes: The current total load of the pumping station unit is obtained by summing the instantaneous flow rates of each pump; Based on the current total load and the performance characteristics of each pump, with the goal of optimizing the overall performance of the unit, the optimal flow distribution value of each pump is solved. The optimal flow allocation value is used as the target load distribution that matches the current total load.

[0012] In some embodiments, determining the load distribution deviation of the pumping station units based on the degree of difference between the actual load distribution of each pump and the target load distribution specifically includes: Calculate the flow deviation between the actual instantaneous flow rate of each pump and the corresponding target flow rate in the target load distribution. Sum the absolute values ​​of the flow deviations of each pump to obtain the total flow deviation. The ratio of the total flow deviation to the current total load is used as the load distribution deviation.

[0013] In some embodiments, the load of each pump is collaboratively redistributed and its speed is synchronously adjusted according to the scheduling priority and the load distribution deviation, until the outlet pressure of each pump converges to a target pressure value that matches the fluid resistance characteristics. Specifically, this includes: According to the scheduling priority from low to high, the load of the lowest priority water pump is reduced in turn and its speed is reduced synchronously, while the load of the highest priority water pump is increased and its speed is increased synchronously. The speed adjustment step size is determined according to the load distribution deviation. After each speed adjustment, the target pressure value under the current fluid resistance characteristics is recalculated, and the deviation between the outlet pressure of each pump and the target pressure value is compared. The maximum deviation is used as the convergence criterion. When the maximum deviation is less than the preset pressure tolerance and the load distribution deviation drops below the preset threshold, the convergence is determined to be complete, and the speed and load distribution of each water pump are locked.

[0014] In some embodiments, reducing the load of the lowest priority water pump and simultaneously reducing its speed in order of scheduling priority from low to high specifically includes: Identify the pump with the lowest priority in the current scheduling priority sequence, and calculate its adjustable capacity based on the difference between the pump's current load and its rated minimum load. The load transfer amount is calculated by multiplying the load distribution deviation by a preset penalty coefficient. This load transfer amount is then deducted from the adjustable capacity of the water pump, and an equal amount of load is transferred to the water pump with the highest priority. During the load transfer process, the target speed is calculated in reverse according to the pump speed-flow characteristic curve, and the inverter output is controlled by a ramp function to achieve a gradual change in speed.

[0015] Secondly, this application provides a computer device, the computer device including a memory and a processor, the memory storing code, the processor being configured to acquire the code and execute the above-described energy-saving control method for coordinated scheduling of pump station units based on water plant fluid resistance.

[0016] Thirdly, this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-mentioned energy-saving control method for coordinated scheduling of pump station units based on the fluid resistance of a water plant.

[0017] The technical solutions provided by the embodiments disclosed in this application have the following beneficial effects: This application extracts the fluid resistance characteristics of the pipeline system, combines pump performance characteristics with load distribution deviation to construct a collaborative scheduling strategy, and utilizes pressure convergence criteria to achieve closed-loop control, ultimately realizing dynamic load balance control and energy efficiency improvement for the pump station units. First, based on the performance characteristic data of each pump, an performance characteristic mapping table is calibrated for each pump under different instantaneous flow rates, and the comprehensive resistance coefficient of the pipeline system is extracted as an independent physical parameter, providing a physical constraint boundary for pipeline-pump coupling in subsequent load distribution. Second, based on the fluid resistance characteristics and the current outlet pressure of each pump, the additional energy consumption required for each pump to overcome the current pipeline resistance is calculated. Based on this, the initial priority ranking based solely on efficiency is corrected, ensuring that the scheduling priority simultaneously reflects the pump's own energy efficiency and the pipeline matching cost, effectively avoiding hidden energy consumption caused by outlet pressure mismatch in high-efficiency pumps. Then, based on the instantaneous flow rate of each pump, the current total load is determined, and the target load distribution is solved with the goal of optimizing the overall unit efficiency, thereby converting the actual load distribution into a more efficient load distribution. The ratio of the absolute deviation between the load distribution and the target distribution is defined as the load allocation deviation. When the deviation exceeds a preset threshold, collaborative redistribution is triggered. A numerical optimization algorithm is used to determine the optimal flow allocation value for each pump, realizing quantitative evaluation and adaptive adjustment of load allocation. Finally, according to the corrected scheduling priority, the load is transferred from the pump with the lowest priority to the pump with the highest priority. Simultaneously, the target speed is calculated in reverse according to the speed-flow characteristic curve, and the inverter output is controlled by a ramp function. At the same time, the maximum deviation of the target pressure value determined by the outlet pressure and fluid resistance characteristics is used as the convergence criterion. When the deviation is less than the pressure tolerance and the load allocation deviation drops below the threshold, the operating state is locked, forming a closed-loop control mechanism with dual-target convergence of pressure and load. In summary, this application achieves dynamic load balance control based on pipeline-pump coupling through the synergistic effect of pipeline resistance extraction, priority correction, deviation drive, and pressure convergence control, improving the overall energy efficiency and operational stability of the pump station unit. Attached Figure Description

[0018] Figure 1 This is an exemplary flowchart of an energy-saving control method for coordinated scheduling of pump station units based on water plant fluid resistance, according to some embodiments of this application. Figure 2 This is a schematic flowchart illustrating the extraction of fluid resistance characteristics according to some embodiments of this application; Figure 3 This is a schematic flowchart illustrating the process of determining the target load distribution according to some embodiments of this application; Figure 4 This is a schematic diagram of the structure of a pump station unit collaborative scheduling energy-saving control system according to some embodiments of this application; Figure 5This is a schematic diagram of the structure of a computer device for implementing a method for coordinated scheduling and energy-saving control of pump station units based on the fluid resistance of a water plant, according to some embodiments of this application. Detailed Implementation

[0019] To better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] refer to Figure 1 The figure is an exemplary flowchart of an energy-saving control method for coordinated scheduling of pumping station units based on water plant fluid resistance, according to some embodiments of this application. This energy-saving control method for coordinated scheduling of pumping station units based on water plant fluid resistance mainly includes the following steps: In step 101, the operating parameters of each pump in the pumping station unit are monitored, including output power, outlet pressure, instantaneous flow rate and speed.

[0021] In some embodiments, monitoring the operating parameters of each pump in the pumping station unit can be achieved in the following ways: real-time acquisition of outlet pressure via pressure transmitters installed on the outlet pipes of each pump; real-time acquisition of instantaneous flow rate via ultrasonic or electromagnetic flow meters installed on the inlet and outlet pipes of each pump; acquisition of the real-time pump speed via frequency converter or additional speed sensor; and acquisition of output power based on a speed-torque correlation model or directly via motor power monitoring equipment. It should be noted that acquiring output power based on the speed-torque correlation model specifically includes: obtaining the speed-torque characteristic curve of the pump at its rated speed, which is calibrated through bench testing or provided by the pump manufacturer; calculating the corresponding real-time torque from the speed-torque characteristic curve using linear interpolation or a fitting formula based on the current real-time speed; and multiplying the real-time torque by the real-time speed and then dividing by a conversion factor to obtain the pump's output power.

[0022] In step 102, the performance characteristics of each pump under different instantaneous flow rates are calibrated based on the performance characteristic data of each pump.

[0023] It should be noted that the performance characteristic data in this application specifically refers to the efficiency values ​​of each water pump at different instantaneous flow rates, i.e., flow-efficiency relationship data. The performance characteristic data can be obtained in the following way: during the factory calibration or on-site shutdown maintenance of each water pump, the water pump is independently and stably operated at multiple different speed gears using a water pump test bench or on-site variable frequency speed control device. The instantaneous flow rate and shaft power at each gear are recorded, and the actual efficiency at each test point is calculated based on the instantaneous flow rate and shaft power, thereby constructing a dataset of efficiency values ​​corresponding to the water pump at different instantaneous flow rates, which serves as the performance characteristic data.

[0024] In some embodiments, the performance characteristics of each pump at different instantaneous flow rates can be calibrated based on its performance characteristic data using the following steps: Obtain the flow-efficiency curves of each water pump under standard test conditions, and extract multiple discrete flow points and their corresponding efficiency values ​​from the flow-efficiency curves. The efficiency values ​​of intermediate flow points are supplemented by nonlinear interpolation for the intervals between adjacent discrete flow points, forming an efficiency characteristic mapping table within the continuous flow interval; The performance feature mapping table is determined as the calibrated performance features.

[0025] It should be noted that the standard test conditions in this application refer to the stable operating state of the water pump at its rated speed, using clean water as the medium, with the inlet and outlet pipelines conforming to the test specifications and without cavitation.

[0026] In practical applications, the efficiency values ​​of intermediate flow points are supplemented by nonlinear interpolation between adjacent discrete flow points to form an efficiency feature mapping table within a continuous flow interval. This can be achieved as follows: Based on the extracted discrete flow points and their corresponding efficiency values, adjacent discrete flow points are divided into interpolation intervals in ascending order of flow rate. Within each interpolation interval, a cubic polynomial function passing through two endpoints and ensuring the continuity of the first and second derivatives is constructed using cubic spline interpolation. This function is used to calculate the efficiency values ​​corresponding to a predetermined number of intermediate flow points located between two discrete flow points. All original discrete flow points and their efficiency values ​​are merged with all supplemented intermediate flow points and their efficiency values, and arranged in ascending order of flow rate to form a table covering the entire continuous interval from minimum to maximum flow rate, representing the correspondence between flow rate and efficiency. This table serves as the efficiency feature mapping table within the continuous flow interval.

[0027] Preferably, in some embodiments, obtaining the flow-efficiency curves of each pump under standard test conditions can be achieved by the following steps: Drive the water pump to its rated speed and keep it stable. Change the load by adjusting the outlet valve and record the instantaneous flow rate and shaft power at multiple different flow stability points. The actual efficiency at each test point is calculated based on the instantaneous flow rate and shaft power, and the flow-efficiency polynomial curve of the pump at rated speed is obtained by fitting using the least squares method. The polynomial curve is stored as a flow-efficiency curve in the control unit.

[0028] In practical applications, when obtaining the flow-efficiency curves of each pump under standard test conditions, the pump to be tested is first installed on a pump test bench system. This test system includes a variable frequency drive motor, an electromagnetic flowmeter, a pressure transmitter, a torque and speed sensor, and a data acquisition unit. The variable frequency drive motor is started and the pump speed is adjusted to the rated speed. Through closed-loop speed control, the actual speed is stabilized within the preset allowable deviation range of the rated speed. An electric regulating valve is installed at the pump outlet pipeline. By gradually changing the opening of the regulating valve, the pipeline resistance is increased or decreased, thereby stabilizing the instantaneous flow rate of the pump at several different preset flow points. The preset flow points are selected at equal intervals or non-uniformly according to the key region of the flow characteristic curve, from the pump's minimum operating flow rate to its maximum operating flow rate. After adjusting to each preset flow point, the valve opening is kept constant, and the system is considered to have reached a stable state when the fluctuations of the flowmeter and pressure transmitter readings are continuously and stably within the preset error range. Under stable conditions, the instantaneous flow rate measured by the electromagnetic flowmeter, the shaft power measured by the torque-speed sensor, and the inlet-outlet pressure difference measured by the pressure transmitter are synchronously read and recorded. The shaft power is the product of torque and angular velocity. Based on the recorded instantaneous flow rate, inlet-outlet pressure difference, and shaft power, the actual efficiency at the test point is calculated using the pump efficiency calculation formula. The formula is: efficiency equals the density of the conveyed medium multiplied by the gravitational acceleration multiplied by the instantaneous flow rate multiplied by the head, divided by the shaft power. The head is determined by the sum of the inlet-outlet pressure difference and the velocity-head difference. The above stable measurement and efficiency calculation process is repeated for all preset flow points to obtain a set of values ​​based on the instantaneous flow rate and the corresponding actual efficiency. The system generates a data set of actual efficiency. This data set is then input into a data fitting module, where a least squares method is used for polynomial regression fitting. A cubic polynomial is selected as the fitting function, with instantaneous flow rate as the independent variable and actual efficiency as the dependent variable. The polynomial coefficients that minimize the sum of squared residuals for all data points are calculated, resulting in a continuous and smooth flow-efficiency polynomial curve. The coefficients of this polynomial curve are stored in the memory of the control unit corresponding to the water pump, and are associated with the recorded fluid medium temperature and density parameters during the test. This polynomial curve serves as the flow-efficiency curve of the water pump at its rated speed, and can be used to query the efficiency value corresponding to any instantaneous flow rate.

[0029] In step 103, the fluid resistance characteristics of the pipeline system are extracted, and the scheduling priority of each pump is determined based on the fluid resistance characteristics, the current operating parameters of each pump and their corresponding performance characteristics.

[0030] In some embodiments, reference Figure 2 As shown in the figure, this is a schematic flowchart of extracting fluid resistance characteristics according to some embodiments of this application. In this embodiment, the extraction of fluid resistance characteristics of a pipeline system can be achieved by the following steps: In step 1031, the inlet and outlet pressure difference data of the pump station unit in multiple stable operating ranges with different total flow rates are collected, and the corresponding total flow rates are recorded simultaneously; In step 1032, the total flow rate and inlet / outlet pressure difference data for each group are substituted into the resistance characteristic function, and the comprehensive resistance coefficient of the pipeline system is determined through regression analysis. In step 1033, the comprehensive resistance coefficient is used as the fluid resistance characteristic characterizing the relationship between pressure difference and flow rate in the pipeline system.

[0031] The comprehensive resistance coefficient in this application is an inherent parameter characterizing the ratio of pressure difference to the square of flow rate in a pipeline system, reflecting the combined effect of frictional resistance and local resistance.

[0032] In practical applications, the overall resistance coefficient of the pipeline system can be determined by substituting the total flow rate and inlet / outlet pressure difference data of each group into the resistance characteristic function and performing regression analysis. This can be achieved in the following way: The average total flow rate in each group of valid sample points is taken as the flow rate value, and the average inlet / outlet pressure difference is taken as the pressure difference value. These values ​​are then substituted into the known resistance characteristic function ΔH = k × Q. 2 Here, ΔH represents the total pressure difference between the inlet and outlet of the pipeline system, k represents the comprehensive resistance coefficient of the pipeline system, and Q represents the total flow rate through the pipeline system. For at least a predetermined number of valid sample points, a quadratic equation with the comprehensive resistance coefficient as the unknown can be constructed for each sample point. After solving all the equations simultaneously, the least squares method is used for regression analysis. That is, a normal equation system is constructed with the squared flow rate of each sample point as input and the pressure difference as the observed value. The optimal estimate of the comprehensive resistance coefficient that minimizes the sum of squared residuals of all sample points is obtained. This optimal estimate is used as the comprehensive resistance coefficient of the pipeline system, where the friction coefficient and local resistance coefficient are implicit in the comprehensive resistance coefficient and are not decomposed separately. Finally, the calculated comprehensive resistance coefficient is used as the fluid resistance characteristic characterizing the relationship between pressure difference and flow rate in the pipeline system.

[0033] Preferably, in some embodiments, the inlet and outlet pressure difference data of the pump station unit in multiple stable operating ranges with different total flow rates can be obtained by the following steps: Based on the daily water supply flow rate change curve of the water plant, several typical load periods were selected, and stable differential pressure and flow rate data were continuously collected within a preset time period in each period. The collected differential pressure data is filtered using a moving average to remove abnormal fluctuations. The filtered differential pressure data and the average total flow rate of the corresponding time period are used as a set of effective sample points. At least a preset number of effective sample points under different total flow rates are obtained as input for regression analysis.

[0034] In practical applications, when collecting inlet and outlet pressure difference data of pump station units in multiple stable operating ranges with different total flow rates, the following steps are taken: First, the three typical load periods of the day—low peak, average peak, and peak—are identified based on the historical daily water supply flow variation curve of the water plant. The selection of each period must ensure that the fluctuation range of the total water supply flow of the water plant within that period does not exceed a preset fluctuation threshold to meet the stable operation conditions. Within each typical load period, pressure transmitters and total flow meters installed on the inlet and outlet main pipes of the pump station units are used to continuously collect inlet and outlet pressure difference data and corresponding total flow data at a preset sampling frequency for a preset duration. The preset duration should cover at least several complete pump adjustment cycles within that period. Then, the collected raw pressure difference data sequence is processed using a known moving average filtering method, i.e., a fixed-length sliding window is set and the arithmetic mean of all pressure difference data within the window is calculated as the filter at the center point of the window. The output is processed by sliding a window to traverse the entire data sequence to eliminate random fluctuations caused by minor pipeline vibrations, sensor noise, or water turbulence. After filtering, points in the differential pressure data sequence that deviate significantly from adjacent values ​​by more than a preset multiple of the standard deviation are identified as abnormal fluctuation points and removed. The arithmetic mean of the differential pressure data after filtering and removing abnormal points is then taken to obtain the average differential pressure value for that period. At the same time, the arithmetic mean of the total flow data for the same period is taken to obtain the average total flow for that period. The average differential pressure and the average total flow are combined into a set of valid sample points. The above operation is repeated to obtain each set of valid sample points in different typical load periods of at least a preset number of groups, ensuring that the average total flow corresponding to each set of sample points has significant differences and covers the flow range of the pump station unit during daily operation. Finally, these valid sample points are used as input data for subsequent regression analysis to solve the comprehensive resistance coefficient of the pipeline system.

[0035] In some embodiments, determining the scheduling priority of each pump based on the fluid resistance characteristics, the current operating parameters of each pump, and their corresponding performance characteristics can be achieved through the following steps: Based on the current instantaneous flow rate of each pump, the corresponding current efficiency is queried from the performance characteristics, and the pumps are initially sorted from high to low according to their current efficiency. Based on the fluid resistance characteristics and the current outlet pressure of each pump, calculate the additional energy consumption required for each pump to overcome the current pipeline resistance, and correct the initial ranking based on the additional energy consumption; The scheduling priority of each water pump is determined based on the revised sorting results.

[0036] The scheduling priority in this application is a comprehensive ranking result used to determine the order of water pumps in the pumping station unit during load distribution and speed regulation.

[0037] In practical applications, the specific implementation method for querying the corresponding current efficiency from the performance characteristics based on the current instantaneous flow rate of each pump and initially sorting the pumps from high to low based on their current efficiency is as follows: read the current instantaneous flow rate value of each pump from the control unit, use this instantaneous flow rate value as the query condition, find the corresponding efficiency value in the calibrated performance characteristic mapping table through linear search or interval positioning as the current efficiency, arrange all running pumps in order of current efficiency from high to low, with the most efficient pump at the front and the least efficient pump at the back, and use the arrangement result as the initial sorting.

[0038] In practical applications, based on the fluid resistance characteristics and the current outlet pressure of each pump, the additional energy consumption required for each pump to overcome the current pipeline resistance is calculated. The specific implementation method for correcting the initial ranking based on the additional energy consumption is as follows: The comprehensive resistance coefficient is obtained from the fluid resistance characteristics. The target outlet pressure value of the pipeline system is calculated by combining the current total flow rate of the pumping station units. This target pressure value = density of the conveyed medium × gravitational acceleration × comprehensive resistance coefficient × square of the current total flow rate. For each pump, its current outlet pressure is compared with the target pressure value: if the current outlet pressure is higher than the target pressure value, the excess pressure value is multiplied by the instantaneous flow rate of the pump and then divided by the current efficiency of the pump to obtain the additional energy consumption value wasted by the pump due to the excessively high outlet pressure; if the current outlet pressure is lower than the target pressure value, the additional energy consumption value is zero. The initial ranking is adjusted according to the order of additional energy consumption values ​​from largest to smallest, moving the pump with the largest additional energy consumption to the back of the ranking and moving the pump with the smallest additional energy consumption to the front. If multiple pumps have similar additional energy consumption, the relative order in the initial ranking is retained, and the adjusted sequence is used as the corrected ranking.

[0039] In practical applications, the specific implementation method for determining the scheduling priority of each pump based on the corrected sorting result is as follows: the pump ranked first in the corrected sorting result is recorded as the highest scheduling priority, the pump ranked last is recorded as the lowest scheduling priority, and so on, corresponding to different priority levels. The scheduling priority value can be calculated using a linear mapping function: assuming the total number of pumps is N, and the sequence number of each pump after the corrected sorting is from 1 to N (sequence number 1 is the first), the priority coefficient is defined as (N - sequence number + 1) / N, with a larger value indicating higher priority; alternatively, the sequence number can be directly used as the priority value, with a smaller value indicating higher priority. Each pump is associated with its corresponding scheduling priority level and stored in the control unit to form a scheduling priority table. During subsequent load allocation, the pump with the highest priority coefficient or the smallest sequence number is prioritized for load increase operations. To facilitate understanding, the following example will be used for further explanation: Assume the pumping station unit has three pumps A, B, and C, each with a current instantaneous flow rate of 100 cubic meters per hour. The current efficiencies, obtained from the efficiency characteristic mapping table, are 85%, 90%, and 80%, respectively. Therefore, the initial ranking is B first, A second, and C third. The current total flow rate is 300 cubic meters per hour, and the target pressure value calculated from the resistance characteristics is 0.5 MPa. Measured outlet pressures: Pump A 0.55 MPa, Pump B 0.52 MPa, Pump C 0.48 MPa. The formula for calculating additional energy consumption is: Additional Energy Consumption = (Outlet Pressure Exceedance × Instantaneous Flow Rate) / Current Efficiency. Converting units to standard units: Pressure Exceedance A is 50000 Pascals, B is 20000 Pascals, and C is 0; Instantaneous Flow Rate is 0.02778 cubic meters per second; Calculation results: Pump A's additional energy consumption is approximately 1634 watts, Pump B's is approximately 617 watts, and Pump C's is 0. Adjusting the priority from highest to lowest based on additional energy consumption, pump A (maximum) should have its priority reduced, while pump C (minimum) should have its priority increased. After the adjustment, the order is B first, C second, and A third. The final scheduling priority is determined as B being the highest, C the second highest, and A the lowest.

[0040] It should be noted that in practical engineering applications, determining scheduling priorities based on the corrected ranking results can simultaneously consider the constraints of both pump energy efficiency and pipeline system resistance matching. This avoids the drawback of traditional methods that prioritize efficiency alone, leading to high-efficiency pumps operating in high-pressure, low-flow areas for extended periods and thus increasing energy consumption. Specifically, by introducing a correction term for the additional energy consumption required to overcome current pipeline resistance, the loss from the outlet pressure deviating from the target pressure value is quantified into a comparable energy consumption index. The load is prioritized for allocation to pumps with the lowest additional energy consumption, bringing the overall unit operating point closer to the pipeline resistance characteristic curve. This effectively reduces throttling losses or pressure build-up caused by excessive outlet pressure, while preventing inefficient operation or cavitation risks due to insufficient pressure. Ultimately, this minimizes the total energy consumption of the pumping station units while meeting water supply demands.

[0041] In step 104, the current total load of the pumping station unit is determined based on the instantaneous flow rate of each pump, and a target load distribution matching the current total load is determined. The load distribution deviation of the pumping station unit is determined based on the degree of difference between the actual load distribution of each pump and the target load distribution.

[0042] In some embodiments, reference Figure 3 As shown in the figure, this is a schematic flowchart illustrating the determination of a target load distribution according to some embodiments of this application. In this embodiment, the current total load of the pumping station units is determined based on the instantaneous flow rate of each pump, and the target load distribution matching the current total load can be determined by the following steps: In step 1041, the instantaneous flow rates of each pump are summed to obtain the current total load of the pump station unit; In step 1042, based on the current total load and the performance characteristics of each pump, the optimal flow distribution value of each pump is solved with the goal of optimizing the overall performance of the unit. In step 1043, the optimal flow allocation value is used as the target load distribution that matches the current total load.

[0043] In this application, the current total load is the cumulative flow value used to characterize the sum of the instantaneous flow outputs of all operating pumps in the pumping station unit at the current moment; the optimal flow allocation value is the target flow combination of each pump used to maximize the weighted sum of the efficiency of each pump in the pumping station unit under the premise of satisfying the current total load.

[0044] In practical application, firstly, the instantaneous flow rate of each running water pump is read from the control unit at the current moment. These instantaneous flow rate values ​​are summed, and the sum is the current total load of the pumping station unit. This current total load reflects the total flow output capacity required by the pumping station unit to meet the water supply demand of the water plant. The summation result is used as the current total load. Then, with the current total load as a constraint, the instantaneous flow rate of each water pump as the decision variable, and the efficiency values ​​corresponding to different flow points in the efficiency characteristic mapping table of each water pump as the basis, an optimization model is established with the goal of maximizing the overall efficiency of the unit. The objective function of this optimization model is that the overall efficiency of the unit is equal to the sum of the products of the instantaneous flow rate and the corresponding efficiency of each water pump divided by the current total load. The corresponding efficiency is obtained by querying the efficiency characteristic mapping table of each water pump according to its own instantaneous flow rate. The constraints are that the sum of the instantaneous flow rates of all pumps equals the current total load, and the instantaneous flow rate of each pump is between its rated minimum and rated maximum flow rates. A known numerical optimization algorithm is then used to solve the optimization model. That is, under the premise of satisfying the above constraints, a set of instantaneous flow rate values ​​for each pump is found that maximizes the objective function. This set of flow rate values ​​is the optimal flow allocation value, and the solution is used as the optimal flow allocation value for each pump. Finally, the optimal flow allocation values ​​of all pumps are arranged according to their pump numbers to obtain a flow allocation vector composed of the target flow rates of each pump. This vector specifies the ideal flow share that each pump should bear under the current total load, and this vector is used as the target load distribution.

[0045] In some embodiments, determining the load distribution deviation of the pumping station units based on the degree of difference between the actual load distribution of each pump and the target load distribution can be achieved through the following steps: Calculate the flow deviation between the actual instantaneous flow rate of each pump and the corresponding target flow rate in the target load distribution. Sum the absolute values ​​of the flow deviations of each pump to obtain the total flow deviation. The ratio of the total flow deviation to the current total load is used as the load distribution deviation.

[0046] The total flow deviation in this application is the cumulative sum of the absolute values ​​of the deviations between the actual instantaneous flow rate of each pump and the target flow rate; the load distribution deviation is a normalized index used to measure the relative degree of deviation between the current actual load distribution and the target load distribution.

[0047] In practical application, firstly, the actual instantaneous flow rate of each operating pump is read from the control unit, and the target flow rate corresponding to that pump is obtained from the target load distribution. The difference between the actual instantaneous flow rate and the target flow rate is taken as the absolute value of the flow deviation of that pump. The absolute values ​​of the flow deviations of all operating pumps are summed, and the sum is the total flow deviation. The total flow deviation is used as the original cumulative value describing the degree of deviation in the overall load distribution of the pumping station units. Then, the current total load value is obtained, which is equal to the sum of the actual instantaneous flow rates of each pump. The total flow deviation is then divided by the current total load, and the quotient is the load distribution deviation degree. This load distribution deviation degree is a dimensionless value between 0 and 1. 0 indicates that the actual instantaneous flow rate of all pumps is completely consistent with the target flow rate, and a value greater than 0 indicates that there is a deviation, and the larger the value, the more serious the deviation. This load distribution deviation degree is used as the benchmark indicator for judging whether to trigger coordinated reallocation. In step 105, when the load distribution deviation exceeds a preset threshold, the load of each water pump is coordinated and redistributed according to the scheduling priority and the load distribution deviation, and their speed is adjusted synchronously until the outlet pressure of each water pump converges to the target pressure value that matches the fluid resistance characteristics.

[0048] It should be noted that when the load distribution deviation exceeds the preset threshold, it indicates that there is a significant deviation between the current actual load distribution and the target load distribution of the pump station unit, and the overall operating efficiency of the unit deviates from the optimal state. Therefore, it is necessary to coordinately redistribute the load of each pump according to the scheduling priority and synchronously adjust its speed, that is, to transfer the load from the pump with low priority to the pump with high priority, and at the same time adjust the speed accordingly, so as to reduce the load distribution deviation and make the outlet pressure of each pump converge to the target pressure value that matches the fluid resistance characteristics.

[0049] In some embodiments, the coordinated redistribution of the load of each pump and the synchronous adjustment of its speed according to the scheduling priority and the load distribution deviation, until the outlet pressure of each pump converges to a target pressure value that matches the fluid resistance characteristics, can be achieved by the following steps: According to the scheduling priority from low to high, the load of the lowest priority water pump is reduced in turn and its speed is reduced synchronously, while the load of the highest priority water pump is increased and its speed is increased synchronously. The speed adjustment step size is determined according to the load distribution deviation. After each speed adjustment, the target pressure value under the current fluid resistance characteristics is recalculated, and the deviation between the outlet pressure of each pump and the target pressure value is compared. The maximum deviation is used as the convergence criterion. When the maximum deviation is less than the preset pressure tolerance and the load distribution deviation drops below the preset threshold, the convergence is determined to be complete, and the speed and load distribution of each water pump are locked.

[0050] In practical applications, when performing coordinated redistribution and speed regulation, the controller first reads the current scheduling priority sequence and determines the pumps whose load needs to be reduced and their corresponding adjustable capacities according to their priority from low to high. Simultaneously, the pump with the highest priority is designated as the load receiver. The load transfer amount for this round is calculated based on the product of the current load distribution deviation and a preset penalty coefficient. This transfer amount is deducted from the current load of the pump with the lowest priority and added equally to the pump with the highest priority, thus achieving centralized load distribution to high-efficiency pumps. Simultaneously with load transfer, the load change is reverse-engineered to the target speed using the speed-flow characteristic curves of each pump. The ramp function generator of the frequency converter smoothly changes the speed to the target value at a preset rate, thereby suppressing water hammer effects. After each round of regulation, the controller recalculates the target pressure value based on the current total flow rate and the pipeline comprehensive resistance coefficient. It also collects the outlet pressure of all operating pumps, calculates the absolute deviation between the outlet pressure of each pump and the target pressure value, and takes the maximum value as the convergence criterion. The actual outlet pressure deviation is compared with the preset pressure tolerance, and the current load distribution deviation is compared with the preset threshold. Only when both meet the convergence condition—that is, the outlet pressure deviation of all pumps is less than the pressure tolerance and the load distribution deviation drops below the threshold—the controller determines that the system has stabilized, locks the current speed and load distribution status of each pump, and exits the regulation process. In this implementation, the speed-flow characteristic curve, ramp function control, resistance characteristic function, and deviation comparison are all well-known technologies in the field of pump station control. This application organically combines them and integrates them into a priority and deviation-driven closed-loop regulation framework, achieving coordinated convergence of pressure and load as dual objectives.

[0051] Preferably, in some embodiments, the following steps can be used to reduce the load of the lowest priority pump and simultaneously reduce its speed in order of scheduling priority from low to high: Identify the pump with the lowest priority in the current scheduling priority sequence, and calculate its adjustable capacity based on the difference between the pump's current load and its rated minimum load. The load transfer amount is calculated by multiplying the load distribution deviation by a preset penalty coefficient. This load transfer amount is then deducted from the adjustable capacity of the water pump, and an equal amount of load is transferred to the water pump with the highest priority. During the load transfer process, the target speed is calculated in reverse according to the pump speed-flow characteristic curve, and the inverter output is controlled by a ramp function to achieve a gradual change in speed.

[0052] It should be noted that this application adopts a coordinated control method based on scheduling priority and load allocation deviation. Its core advantage lies in directly coupling the load transfer amount to the real-time deviation and achieving adaptive adjustment intensity through a penalty coefficient. Compared with the fixed step size or proportional allocation method commonly used in the prior art, this application can dynamically adjust the load size of each transfer according to the deviation of the current load allocation, avoiding the problems of over-adjustment with small deviations and slow response with large deviations. At the same time, by transferring the load from the lowest priority water pump with the largest adjustable capacity to the highest priority water pump, it ensures that the adjustment process always takes place within the equipment safety boundary and will not trigger low flow protection. In addition, the introduction of ramp function control of the frequency converter output makes the speed transition smooth, effectively suppressing the water hammer impact and pressure oscillation that are easily caused by traditional step adjustment.

[0053] In practical applications, the pump with the lowest priority in the current scheduling priority sequence is identified, and its adjustable capacity is calculated based on the difference between its current load and rated minimum load. This can be achieved in the following way: Find the pump with the lowest priority in the current scheduling priority sequence from the scheduling priority table and record it as the pump with the lowest priority; read the pump's current instantaneous flow rate as its current load, and obtain the rated minimum flow rate value set at the factory. Subtract the rated minimum flow rate from the current load, and use the difference as the adjustable capacity of the pump.

[0054] In practical applications, the load transfer amount is calculated by multiplying the load distribution deviation by a preset penalty coefficient. The load transfer amount is then deducted from the adjustable capacity of the pump and transferred to the highest priority pump in the following manner: The calculated load distribution deviation is multiplied by the preset penalty coefficient, and the product is used as the load transfer amount to be transferred in this round. It is then determined whether this load transfer amount is greater than the adjustable capacity of the lowest priority pump. If it is, the adjustable capacity is used as the actual transfer amount. This load transfer amount is deducted from the current load of the lowest priority pump, and the deducted load transfer amount is added to the current load of the highest priority pump in equal measure. After the load transfer is completed, the adjusted load values ​​of each pump are used as the output of this step. It should be further explained that the penalty coefficient can be preset based on the total installed capacity of the pumping station units and the number of operating pumps, for example, taking a constant between 0.2 and 0.5. The specific value is obtained through offline simulation or on-site tuning. During simulation, the load distribution deviation changes from 0.1 to 0.5 as the excitation, and the adjustment time for the overall unit efficiency to recover to more than 95% of the optimal value is the optimization objective. The coefficient that minimizes the adjustment time is selected as the final tuning value. Alternatively, an adaptive adjustment method can be adopted, that is, the penalty coefficient is corrected in real time according to the rate of change of the current load distribution deviation. When the deviation increases rapidly, the penalty coefficient is increased to accelerate the load transfer speed. When the deviation tends to stabilize, the penalty coefficient is decreased to reduce overshoot, thereby achieving a balance between rapid convergence and smooth adjustment.

[0055] In practical applications, during load transfer, the target speed is simultaneously calculated in reverse according to the pump's speed-flow characteristic curve, and the inverter output is controlled using a ramp function. This gradual speed change can be achieved in the following way: During load transfer, for the pump with the lowest priority whose load is reduced, the pump's speed-flow characteristic curve is consulted based on the load reduction amount. The corresponding speed reduction is obtained by back-interpolation from the curve, and the target speed is obtained by subtracting this reduction amount from the current speed. For the pump with the highest priority whose load is increased, the target speed is calculated based on the pump's speed-flow characteristic curve according to the load increase amount. The increase in speed is obtained by positive interpolation of the characteristic curve. The target speed is obtained by adding the increase to the current speed. The target speeds of the two water pumps are input into their respective frequency converters. The frequency converters use a ramp function generator to gradually change the output frequency from the current frequency to the frequency corresponding to the target frequency, thus achieving a slow change in speed. The purpose of using ramp function control to control the output of the frequency converter is to limit the rate of change of speed and avoid water hammer effect in the pipeline caused by sudden large speed changes. After ramp control is completed, the speed corresponding to the stable frequency output by the frequency converter is taken as the actual operating speed after this adjustment.

[0056] On the other hand, in some embodiments, this application provides a pump station unit coordinated scheduling energy-saving control system, with reference to Figure 4The figure is a schematic diagram of the structure of a pump station unit collaborative scheduling energy-saving control system according to some embodiments of this application. The pump station unit collaborative scheduling energy-saving control system 400 includes: a monitoring module 401, a processing module 402, and a control module 403, which are described below: Monitoring module 401, in this application, is mainly used to monitor the operating parameters of each water pump in the pumping station unit. The operating parameters include output power, outlet pressure, instantaneous flow rate and speed. Processing module 402, in this application, is used to calibrate the performance characteristics of each water pump under different instantaneous flow rates based on the performance characteristic data of each water pump. In this application, the processing module 402 is also used to extract the fluid resistance characteristics of the pipeline system, and determine the scheduling priority of each water pump based on the fluid resistance characteristics, the current operating parameters of each water pump and its corresponding performance characteristics. In this application, the processing module 402 is also used to determine the current total load of the pump station unit based on the instantaneous flow rate of each water pump, and to determine the target load distribution that matches the current total load, and to determine the load distribution deviation of the pump station unit based on the degree of difference between the actual load distribution of each water pump and the target load distribution. The control module 403 in this application is mainly used to coordinately redistribute the load of each water pump and synchronously adjust its speed according to the scheduling priority and the load distribution deviation when the load distribution deviation exceeds the preset threshold, until the outlet pressure of each water pump converges to the target pressure value that matches the fluid resistance characteristics.

[0057] In addition, this application also provides a computer device, which includes a memory and a processor. The memory stores code, and the processor is configured to acquire the code and execute the above-described energy-saving control method for coordinated scheduling of pump station units based on water plant fluid resistance.

[0058] In some embodiments, reference Figure 5 The figure is a schematic diagram of the structure of a computer device for implementing a pump station unit collaborative scheduling energy-saving control method based on water plant fluid resistance, according to some embodiments of this application. The pump station unit collaborative scheduling energy-saving control method based on water plant fluid resistance in the above embodiments can be implemented through... Figure 5 The computer device shown is used to implement this, and the computer device 500 includes at least one processor 501, a communication bus 502, a memory 503, and at least one communication interface 504.

[0059] Processor 501 can be a general-purpose central processing unit (CPU) or an application-specific integrated circuit (ASIC).

[0060] The communication bus 502 can be used to transmit information between the aforementioned components.

[0061] Memory 503 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CDROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital versatile optical discs, Blu-ray discs, etc.), magnetic disks or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. Memory 503 may exist independently and be connected to processor 501 via communication bus 502. Memory 503 may also be integrated with processor 501.

[0062] The memory 503 stores program code for executing the scheme of this application, and its execution is controlled by the processor 501. The processor 501 executes the program code stored in the memory 503. The program code may include one or more software modules. The energy-saving control method for coordinated scheduling of pump station units based on water plant fluid resistance in the above embodiments can be implemented by the processor 501 and one or more software modules in the program code in the memory 503.

[0063] Communication interface 504 uses any transceiver-like device to communicate with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.

[0064] In a specific implementation, as one example, a computer device may include multiple processors, each of which may be a single-core (single CPU) processor or a multi-core (multi CPU) processor. Here, a processor may refer to one or more devices, circuits, and / or processing cores used to process data (e.g., computer program instructions).

[0065] The aforementioned computer device can be a general-purpose computer device or a special-purpose computer device. In specific implementations, the computer device can be a desktop computer, a portable computer, a network server, a handheld digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, a communication device, or an embedded device. This application does not limit the type of computer device.

[0066] In addition, this application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the above-mentioned energy-saving control method for coordinated scheduling of pump station units based on the fluid resistance of a water plant.

[0067] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0068] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for energy-saving control of pump station units based on fluid resistance in water plants, characterized in that, The method includes the following steps: Monitor the operating parameters of each pump in the pumping station unit, including output power, outlet pressure, instantaneous flow rate and speed; Based on the performance characteristics data of each water pump, its performance characteristics under different instantaneous flow rates are calibrated; Extract the fluid resistance characteristics of the pipeline system, and determine the scheduling priority of each pump based on the fluid resistance characteristics, the current operating parameters of each pump and their corresponding performance characteristics. The current total load of the pumping station units is determined based on the instantaneous flow rate of each pump, and a target load distribution matching the current total load is determined. The load distribution deviation of the pumping station units is determined based on the degree of difference between the actual load distribution of each pump and the target load distribution. When the load distribution deviation exceeds a preset threshold, the load of each water pump is coordinated and redistributed according to the scheduling priority and the load distribution deviation, and their speed is adjusted synchronously until the outlet pressure of each water pump converges to the target pressure value that matches the fluid resistance characteristics.

2. The method as described in claim 1, characterized in that, Based on the performance characteristic data of each water pump, the performance characteristics at different instantaneous flow rates are calibrated, specifically including: Obtain the flow-efficiency curves of each water pump under standard test conditions, and extract multiple discrete flow points and their corresponding efficiency values ​​from the flow-efficiency curves. The efficiency values ​​of intermediate flow points are supplemented by nonlinear interpolation for the intervals between adjacent discrete flow points, forming an efficiency characteristic mapping table within the continuous flow interval; The performance feature mapping table is determined as the calibrated performance features.

3. The method as described in claim 2, characterized in that, Obtaining the flow-efficiency curves of each water pump under standard test conditions specifically includes: Drive the water pump to its rated speed and keep it stable. Change the load by adjusting the outlet valve and record the instantaneous flow rate and shaft power at multiple different flow stability points. The actual efficiency at each test point is calculated based on the instantaneous flow rate and shaft power, and the flow-efficiency polynomial curve of the pump at rated speed is obtained by fitting using the least squares method. The polynomial curve is stored as a flow-efficiency curve in the control unit.

4. The method as described in claim 1, characterized in that, The fluid resistance characteristics of the extraction pipeline system specifically include: Collect inlet and outlet pressure difference data of pump station units in multiple stable operating ranges with different total flow rates, and record the corresponding total flow rates simultaneously; Substitute the total flow rate and inlet / outlet pressure difference data of each group into the resistance characteristic function, and determine the comprehensive resistance coefficient of the pipeline system through regression analysis. The comprehensive resistance coefficient is used as a fluid resistance characteristic to characterize the relationship between pressure difference and flow rate in a pipeline system.

5. The method as described in claim 4, characterized in that, The specific data collected on the inlet and outlet pressure difference of the pumping station units during multiple stable operating ranges with different total flow rates include: Based on the daily water supply flow rate change curve of the water plant, several typical load periods were selected, and stable differential pressure and flow rate data were continuously collected within a preset time period in each period. The collected differential pressure data is filtered using a moving average to remove abnormal fluctuations. The filtered differential pressure data and the average total flow rate of the corresponding time period are used as a set of effective sample points. At least a preset number of effective sample points under different total flow rates are obtained as input for regression analysis.

6. The method as described in claim 1, characterized in that, Based on the fluid resistance characteristics, the current operating parameters of each pump, and their corresponding performance characteristics, the scheduling priority of each pump is determined, specifically including: Based on the current instantaneous flow rate of each pump, the corresponding current efficiency is queried from the performance characteristics, and the pumps are initially sorted from high to low according to their current efficiency. Based on the fluid resistance characteristics and the current outlet pressure of each pump, calculate the additional energy consumption required for each pump to overcome the current pipeline resistance, and correct the initial ranking based on the additional energy consumption; The scheduling priority of each water pump is determined based on the revised sorting results.

7. The method as described in claim 1, characterized in that, Determining the current total load of the pumping station units based on the instantaneous flow rate of each pump, and determining the target load distribution that matches the current total load specifically includes: The current total load of the pumping station unit is obtained by summing the instantaneous flow rates of each pump; Based on the current total load and the performance characteristics of each pump, with the goal of optimizing the overall performance of the unit, the optimal flow distribution value of each pump is solved. The optimal flow allocation value is used as the target load distribution that matches the current total load.

8. The method as described in claim 1, characterized in that, The load distribution deviation of the pumping station units is determined based on the degree of difference between the actual load distribution of each pump and the target load distribution. Specifically, this includes: Calculate the flow deviation between the actual instantaneous flow rate of each pump and the corresponding target flow rate in the target load distribution. Sum the absolute values ​​of the flow deviations of each pump to obtain the total flow deviation. The ratio of the total flow deviation to the current total load is used as the load distribution deviation.

9. The method as described in claim 1, characterized in that, Based on the scheduling priority and the load distribution deviation, the load of each water pump is coordinated and its speed is adjusted synchronously until the outlet pressure of each water pump converges to the target pressure value that matches the fluid resistance characteristics. Specifically, this includes: According to the scheduling priority from low to high, the load of the lowest priority water pump is reduced in turn and its speed is reduced synchronously, while the load of the highest priority water pump is increased and its speed is increased synchronously. The speed adjustment step size is determined according to the load distribution deviation. After each speed adjustment, the target pressure value under the current fluid resistance characteristics is recalculated, and the deviation between the outlet pressure of each pump and the target pressure value is compared. The maximum deviation is used as the convergence criterion. When the maximum deviation is less than the preset pressure tolerance and the load distribution deviation drops below the preset threshold, convergence is determined to be complete, and the speed and load distribution of each water pump are locked.

10. The method as described in claim 9, characterized in that, According to the scheduling priority from low to high, the load of the lowest priority water pump is reduced in turn, and its speed is reduced synchronously. Specifically, this includes: Identify the pump with the lowest priority in the current scheduling priority sequence, and calculate its adjustable capacity based on the difference between the pump's current load and its rated minimum load. The load transfer amount is calculated by multiplying the load distribution deviation by a preset penalty coefficient. This load transfer amount is then deducted from the adjustable capacity of the water pump, and an equal amount of load is transferred to the water pump with the highest priority. During the load transfer process, the target speed is calculated in reverse according to the pump speed-flow characteristic curve, and the inverter output is controlled by a ramp function to achieve a gradual change in speed.

Images