A control system of a smart pump house

Abstract

The present application relates to the technical field of pump house control, and discloses a control system of intelligent pump house, which comprises a PLC control cabinet, a frequency converter, a variable frequency pump group, a shared water outlet main pipe and a running amount acquisition unit. The running amount acquisition unit collects the main pipe pressure, the main pipe flow, the power consumption of the pump group and the water pump running frequency in the same control scanning cycle. When the same pump group is running, the same valve is in place and the frequency converter is increasing the frequency, the PLC control cabinet identifies the combined state that the water pump running frequency and the power consumption of the pump group are rising while the main pipe pressure and the main pipe flow are not rising, continuously confirms the effective frequency command, and requests the standby pump to be put into operation when the pressure is still low. The present application is used for improving the frequency response disposal of the pump house and the timeliness of the standby pump access.

Description

Technical Field

[0001] This invention relates to the field of pump house control technology, and more specifically, to a control system for a smart pump house. Background Technology

[0002] In actual operation, a typical configuration of a secondary water supply pump station includes a water tank, variable frequency pump set, shared outlet main pipe, pressure transmitter, flow meter, power meters, frequency converter, PLC control cabinet, field touch screen, and upper-level monitoring terminal. Field control usually uses the main pipe pressure as closed-loop feedback, and the PLC control cabinet outputs frequency commands to the frequency converter, causing the currently operating pump to increase or decrease its frequency according to changes in water load. At the same time, the water tank level permission status, emergency stop reset status, valve position status, operation feedback, and fault feedback are used for start / stop permission, alarm interlocking, and remote monitoring.

[0003] During commissioning and maintenance, increasing the frequency of a single pump does not necessarily lead to a synchronous increase in pipeline pressure or flow. Issues such as pump efficiency deviations, abnormal outlet valve status, increased local resistance, delayed pump switching, and disconnection between inverter feedback and hydraulic output can all cause a continued increase in electrical energy input, while the increase in water supply to the shared main outlet pipe remains insignificant. If the PLC control program continues to push up the frequency of the currently operating pump solely based on pressure deviations, problems such as repeated frequency command stacking, increased energy consumption, delayed pump relay, and insufficient on-site alarm data can easily occur.

[0004] From an engineering control perspective, pump stations need to integrate inverter feedback, pump power consumption, main pipe pressure, and main pipe flow rate within the same control scan cycle to distinguish between states where control actions have been executed and those where the effluent response has not improved accordingly. Relying solely on a single pressure reading makes it difficult to determine the differences between external water usage fluctuations, changes in pipeline resistance, or abnormal pump responses; similarly, relying solely on flow readings makes it difficult to confirm whether inverter frequency increases have been implemented. Therefore, on-site control needs to be based on existing instrument and actuator feedback, integrating frequency maintenance, standby pump requests, valve sequence start / stop, and protection interlocks into a single traceable process.

[0005] Existing smart pump station platforms typically possess data uploading, remote monitoring, event logging, and alarm management capabilities, but these capabilities primarily serve operational demonstrations and post-event traceability. In situations where the pipeline does not provide effective additional power after frequency increase, the lack of a field control branch directly linked to pump unit switching and protection interlocks necessitates operators relying on experience to determine whether to activate the standby pump. The consistency and timeliness of these actions are affected by on-site conditions. Summary of the Invention

[0006] This invention provides a control system for a smart pumping station, which solves the technical problems mentioned in the background art.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution.

[0008] A control system for a smart pumping station includes a PLC control cabinet, a frequency converter, a frequency converter pump set, a common outlet main pipe, and an operating data acquisition unit. The frequency converter pump set includes a currently operating pump and a standby pump. The outlets of each pump are connected to the common outlet main pipe. The PLC control cabinet includes a target pressure management unit, a reversal flag generation unit, a pump pipe response reversal point confirmation unit, a frequency converter voltage stabilization unit with reversal branches, and a standby pump control unit. The target pressure management unit stores the target pressure and forms a target pressure range with a lower limit boundary; The operation data acquisition unit acquires the main pipe pressure, main pipe flow rate, pump set power consumption and pump operating frequency in the same control scan cycle, and saves the above operation data corresponding to adjacent control scan cycles; The reversal flag generation unit identifies the combined state of pump operating frequency increase, pump group power consumption increase, and main pipe pressure and main pipe flow not increase in adjacent control scan cycles when the same operating pump combination, the same valve in position and the frequency converter is in frequency increase operation, and generates a reversal flag. The pump tube response reversal point confirmation unit confirms the pump tube response reversal point when the reversal flag is established for two consecutive control scan cycles. After confirming the pump tube response reversal point, the variable frequency voltage regulator unit with reversal branch stops adding frequency increment to the frequency converter frequency command, keeps the frequency converter frequency command at the effective frequency command corresponding to the control scan cycle before confirming the pump tube response reversal point, and issues a standby pump request when the main pipe pressure is lower than the lower limit boundary of the target pressure range. The standby pump control unit responds to standby pump requests and controls the standby pump to be activated.

[0009] Compared with the prior art, the present invention has the following substantial features and significant progress: This invention integrates the PLC control cabinet, frequency converter, variable frequency pump set, common outlet main pipe, and the acquisition links of main pipe pressure, main pipe flow, pump set power consumption, and pump operating frequency into the same control process. When the frequency converter increases frequency and power consumption increases but the pipeline pressure and flow do not increase synchronously, the PLC control cabinet promptly maintains an effective frequency command and issues a backup pump request. This reduces the ineffective energy consumption and control fluctuations caused by the current operating pump continuing to increase frequency. It also enables the backup pump to be connected and interlocked with valve status, operation feedback, and fault feedback, and provides an executable basis for on-site alarms, recording, and recovery, thereby improving the stability of pump room water supply control and the efficiency of operation and maintenance. Attached Figure Description

[0010] Figure 1 This is a system architecture and control mechanism diagram of a smart pumping station control system according to the present invention. Detailed Implementation

[0011] The following description is provided in conjunction with the accompanying drawings. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the invention; those skilled in the art can make equivalent substitutions or combinations for the specific implementations.

[0012] This embodiment relates to a control system for a smart pumping station, applicable to water supply sites with tank-based water supply, parallel operation of variable frequency pump sets, and water pump outlets converging into a common main outlet pipe. The control system uses a PLC control cabinet as the main control unit, variable frequency drives and pump sets as the execution objects, the common main outlet pipe as the hydraulic output object, and an operational data acquisition unit as the input for collecting on-site operational data into the PLC control cabinet. Based on existing main pipe pressure, main pipe flow rate, pump set power consumption, and pump operating frequency, the control system enables the PLC control cabinet to determine whether the current frequency increase action results in an effective increased supply response.

[0013] Specifically, in conventional smart pump stations, the PLC control cabinet typically uses the main pipe pressure as feedback and the target pressure as a setpoint to control the frequency converter via frequency commands, causing the frequency converter to drive the currently operating pumps in the variable frequency pump set to increase or decrease their frequency. When the main pipe pressure is lower than the target pressure, conventional variable frequency pressure stabilization control will continue to add frequency increase increments to the frequency converter commands. However, in scenarios where pump set efficiency deviates, local pipeline resistance increases, outlet side conditions are abnormal, variable frequency pump set switching is delayed, or the output of the currently operating pump cannot be further improved, the pump operating frequency may have already increased, and the pump set power consumption may have also increased, but the main pipe pressure and flow rate on the shared outlet main pipe have not increased accordingly. If the PLC control cabinet continues to add frequency increase increments, it can easily lead to ineffective energy consumption, fluctuations in water supply control, and delays in the activation of standby pumps.

[0014] See Figure 1 The PLC control cabinet 100 serves as the outer control unit, and the target pressure management unit 110, the reversal flag generation unit 130, the pump pipe response reversal point confirmation unit 140, the variable frequency voltage stabilizing unit 150 with reversal branch, and the standby pump control unit 160 are all located inside the PLC control cabinet 100; the operation quantity acquisition unit 120 is located on the operation quantity inlet side of the PLC control cabinet 100; the frequency converter 200, the variable frequency pump group 300, and the common outlet water main pipe 400 are located on the execution and feedback link side of the PLC control cabinet 100.

[0015] The PLC control cabinet 100 can be composed of a programmable logic controller and its input / output modules, or it can be composed of an industrial controller with equivalent PLC program control functions. The PLC control cabinet 100 and the frequency converter 200 can transmit frequency converter commands, frequency converter ready status, frequency converter operation feedback status, water pump operating frequency, and fault feedback through fieldbus, industrial Ethernet, or hard-wired interface.

[0016] The inverter 200 receives the inverter frequency command from the inverter voltage regulator unit 150 with a reverse branch, and converts the inverter frequency command into a drive output, causing the currently operating pump in the inverter pump set 300 to operate at the corresponding frequency. Simultaneously, the inverter 200 feeds back the water pump operating frequency to the operation data acquisition unit 120, enabling the PLC control cabinet 100 to confirm the direction of change of the water pump operating frequency in adjacent control scan cycles.

[0017] The variable frequency pump set 300 includes currently operating pumps and standby pumps. The currently operating pumps are those driven by the frequency converter 200 and involved in water supply, while the standby pumps are those not currently involved in water supply but can be activated by the standby pump control unit 160 when operating permits are met. The outlets of all pumps converge into a common outlet manifold 400, allowing the manifold pressure and flow rate to reflect the overall output status of the variable frequency pump set 300 to the water supply pipeline.

[0018] The common outlet main pipe 400 receives water from the variable frequency pump set 300 and is equipped with a pressure transmitter for collecting the main pipe pressure and a flow meter for collecting the main pipe flow. Both the main pipe pressure and the main pipe flow are obtained from the common outlet main pipe 400, so that the judgment objects are concentrated in the same water supply output channel.

[0019] The operation data acquisition unit 120 serves as the collection inlet for operation data entering the PLC control cabinet 100. The operation data acquisition unit 120 obtains the main water supply pressure and flow rate from the common outlet main pipe 400, the power consumption of the variable frequency pump set 300, and the pump operating frequency from the frequency converter 200. The operation data acquisition unit 120 then sends these operation data to the reversal flag generation unit 130.

[0020] The target pressure management unit 110 provides the target pressure and target pressure range to the variable frequency voltage regulator unit 150 with a reverse branch. The target pressure can be set locally from the PLC control cabinet 100 or from a remotely authorized setting. The target pressure range is formed based on the allowable deviation or hysteresis in the conventional voltage regulation control of the smart pump room, and the lower limit of the target pressure range is used to determine whether a standby pump request needs to be issued while maintaining the effective frequency command.

[0021] The reversal flag generation unit 130, the pump pipe response reversal point confirmation unit 140, and the variable frequency voltage regulator unit 150 with reversal branch form a continuous link from state recognition to control branch switching. The reversal flag generation unit 130 identifies the joint state and generates a reversal flag; the pump pipe response reversal point confirmation unit 140 confirms the pump pipe response reversal point when the reversal flag is established for two consecutive control scan cycles; after receiving the pump pipe response reversal point, the variable frequency voltage regulator unit 150 with reversal branch stops superimposing the frequency increment, maintains the effective frequency command, and triggers the standby pump request according to the lower limit boundary of the target pressure range.

[0022] The standby pump control unit 160 receives a standby pump request from the variable frequency voltage regulator unit 150 with a reverse branch and outputs a standby pump activation command to the variable frequency pump group 300. The variable frequency pump group 300 feeds back operation feedback and fault feedback to the standby pump control unit 160, enabling the standby pump control unit 160 to confirm whether the standby pump has been successfully activated and to prevent the pump corresponding to the fault feedback from entering the standby pump candidate set.

[0023] Furthermore, detailed implementation methods for the PLC control cabinet and target pressure management unit include: The PLC control cabinet 100 is used to centrally execute data acquisition, judgment, pressure stabilization, standby pump activation, alarm protection, display recording, and recovery checks in a smart pump station control system. The PLC control cabinet 100 includes at least a target pressure management unit 110, a reversal flag generation unit 130, a pump pipe response reversal point confirmation unit 140, a frequency converter voltage stabilization unit 150 with reversal branches, and a standby pump control unit 160. To support subordinate implementations, the PLC control cabinet 100 may also include a data validity check unit, a pump and valve sequential start / stop unit, an alarm and protection coordination unit, and a monitoring, display, recording, and recovery unit.

[0024] The target pressure management unit 110 stores the target pressure and forms a target pressure range with a lower limit boundary. The target pressure is the pressure setpoint that the smart pumping station wants to maintain on the common outlet main pipe 400. The target pressure range is an allowable control interval formed around the target pressure, which is used to avoid frequent switching of control states when the main pipe pressure fluctuates slightly. The lower limit boundary of the target pressure range is the boundary for determining whether the main pipe pressure is still in a state requiring additional supply. After the variable frequency pressure stabilizing unit 150 with the reversing branch confirms the pump pipe response reversal point, it only issues a standby pump request when the main pipe pressure is lower than the lower limit boundary of the target pressure range.

[0025] The target pressure management unit 110 can be implemented using the holding register, recipe parameter area, or human-machine interface setting area within the PLC control cabinet 100. The target pressure can be written via a field touchscreen or via a higher-level monitoring terminal when local remote permission is valid. Regardless of the source of the target pressure, the PLC control cabinet 100 should perform upper and lower limit checks on the target pressure to ensure that it remains within the allowable operating range of the variable frequency pump set 300 and the common outlet main pipe 400.

[0026] In one possible implementation, the target pressure management unit 110 can form a lower limit boundary of the target pressure range based on the target pressure and a preset pressure regulation allowable deviation. If the target pressure is expressed as... The lower limit of the target pressure range is represented as Then, it represents the relationship between the two: ,in, This represents the lower limit of the target pressure range, and its value is derived from the calculation results of the target pressure management unit 110. The target pressure is represented by a value derived from the local setting of the PLC control cabinet 100 or a permitted remote setting. This indicates the allowable deviation in voltage regulation, and its value is derived from the engineering commissioning parameters of conventional voltage regulation control in smart pump rooms.

[0027] It should be noted that the pressure stabilization tolerance uses the same pressure dimension as the target pressure. The pressure stabilization tolerance can be determined by the larger of the proportional value of the target pressure and the pressure transmitter's allowable error.

[0028] If the voltage regulation ratio coefficient is expressed as The allowable error of the pressure transmitter is expressed as Then the allowable deviation for voltage regulation is determined as follows: ,in, This indicates the allowable deviation for pressure stabilization, and its dimensions are the same as the target pressure. This represents the voltage regulation ratio, which is a dimensionless parameter and is taken as 0.02 to 0.05 in a preferred embodiment; Indicates target pressure; This indicates the permissible error of the pressure transmitter, with the same dimensions as the target pressure. The value is derived from the pressure transmitter's nameplate accuracy, calibration certificate, or the pressure measurement error parameters configured in the PLC control cabinet 100. After long-term adjustment of the target pressure, replacement of the pressure transmitter, recalibration of the pressure transmitter, or maintenance of the variable frequency pump unit 300, the target pressure management unit 110 should recheck the pressure stabilization permissible deviation and update the lower limit of the target pressure range accordingly.

[0029] The interface between the target pressure management unit 110 and the variable frequency voltage regulator unit 150 with reverse branch includes at least the target pressure and the target pressure range. When the pump pipe response reverse point is not confirmed, the variable frequency voltage regulator unit 150 with reverse branch outputs a frequency converter command with the main pipe pressure as feedback and the target pressure as a setpoint. After confirming the pump pipe response reverse point, the target pressure management unit 110 continues to provide the target pressure and the target pressure range, enabling the variable frequency voltage regulator unit 150 with reverse branch to determine whether the main pipe pressure is below the lower limit of the target pressure range.

[0030] Specifically, the determination of whether the main pipe pressure has not risen is based on the main pipe pressure in the adjacent control scan cycle. The target pressure and target pressure range only affect the frequency converter voltage regulation control and whether a standby pump request is issued.

[0031] Furthermore, the detailed implementation methods of the operation data acquisition unit and the operation data acquisition component are as follows: The operation data acquisition unit 120 is used to acquire the main pipe pressure, main pipe flow rate, pump set power consumption, and pump operating frequency within the same control scan cycle, and save the above operation data corresponding to adjacent control scan cycles. The operation data acquisition unit 120 saves the operation data of the current control scan cycle, and retains the corresponding operation data of the previous control scan cycle before entering the next control scan cycle, so that the comparison between adjacent control scan cycles can be performed directly.

[0032] The operational data acquisition unit 120 includes a main pipe pressure acquisition component, a main pipe flow acquisition component, a pump set power consumption acquisition component, and a pump operating frequency acquisition component. The main pipe pressure acquisition component is a pressure transmitter installed in the common outlet main pipe 400, used to convert the pressure in the common outlet main pipe 400 into analog, digital, or communication register data readable by the PLC control cabinet 100. The main pipe flow acquisition component is a flow meter installed in the common outlet main pipe 400, used to acquire the flow rate through the common outlet main pipe 400. The pump set power consumption acquisition component is a pump set power meter, used to acquire the power consumption of the variable frequency pump set 300 under current operating conditions. The pump operating frequency acquisition component is the feedback interface of the frequency converter 200, used to read the actual pump operating frequency fed back by the frequency converter 200.

[0033] The main pipe pressure can be expressed as ,in This indicates the current control scan cycle. The total pressure stored in the previous control scan cycle can be expressed as... The total flow rate can be expressed as... The total tube flow rate saved in the previous control scan cycle can be expressed as: The power consumption of the pump unit can be expressed as... The power consumption of the pump unit saved in the previous control scan cycle can be expressed as: The operating frequency of a water pump can be expressed as: The pump operating frequency saved in the previous control scan cycle can be expressed as: .

[0034] To ensure the comparability of the operating data collected by the operating data acquisition unit 120, the PLC control cabinet 100 can perform operating data reading according to a fixed control scan cycle. The specific duration of the control scan cycle can be set according to the refresh capabilities of the PLC control cabinet 100, frequency converter 200, pressure transmitter, flow meter, and pump group power instruments.

[0035] To ensure a defined time correspondence between data from the same control scan cycle and adjacent control scan cycles, the control scan cycle of the reversal flag generation unit 130 in the PLC control cabinet 100 is no shorter than the maximum refresh cycle of the critical operating quantity. If the control scan cycle is expressed as... The refresh cycles for main pipe pressure, main pipe flow, pump power consumption, and pump operating frequency are respectively expressed as: , , and Then the control scan cycle satisfies: ,in, This indicates the control scan cycle, with the dimension being time. This indicates the main pressure refresh cycle, and its value is derived from the effective refresh time of the pressure transmitter or its communication register. This indicates the main flow refresh cycle, and its value is derived from the effective refresh time of the flow meter or its communication register. This indicates the refresh cycle of the pump unit's power consumption, and its value is derived from the effective refresh time of the pump unit's power meter. This indicates the pump operating frequency refresh cycle, and its value is derived from the effective refresh time of the inverter 200 feedback interface.

[0036] At the beginning of each control scan cycle, the operation data acquisition unit 120 first copies the main pipe pressure, main pipe flow rate, pump power consumption, and pump operating frequency from the current storage area to the storage area of ​​the previous control scan cycle. Then, it reads the new operation data for the current control scan cycle and writes it to the current storage area. If any operation data is not updated within the current control scan cycle, the operation data acquisition unit 120 can use the most recently valid sampled value; however, the retention time of the most recently valid sampled value must not exceed one control scan cycle. If the data is still not updated after one control scan cycle, the data validity check unit will determine the corresponding operation data as a communication interruption and prohibit the confirmation of the pump pipe response reversal point.

[0037] When the operation data acquisition unit 120 first enters automatic control, re-enters automatic control after a fault reset, or when the PLC control cabinet 100 is first powered on, it may not have saved the operation data from the previous control scan cycle. At this time, the operation data acquisition unit 120 can use the total pipe pressure, total pipe flow, pump power consumption, and pump operating frequency acquired in the current control scan cycle as initial saved values, and provide the reverse flag generation unit 130 with comparison data of adjacent control scan cycles at the beginning of the next control scan cycle.

[0038] Furthermore, the detailed implementation of the data validity check unit is as follows: The data validity check unit, located within the PLC control cabinet 100, performs engineering value conversions for the main pipe pressure, main pipe flow rate, pump set power consumption, and pump operating frequency. It prevents confirmation of the pump pipe response reversal point if any data point is disconnected, exceeds the range, or experiences a communication interruption. The data validity check unit prevents the reversal flag generation unit 130 from mistakenly identifying sensor disconnections, communication interruptions, incorrect range settings, or abnormal inverter feedback as a combined state.

[0039] For main pipe pressure, the data validity check unit can perform engineering value conversion based on the pressure transmitter's range and signal type. For example, when the main pipe pressure acquisition unit uses an analog signal, the data validity check unit can convert the analog input into main pipe pressure in engineering units; when the main pipe pressure acquisition unit uses communication, the data validity check unit can read the communication register and convert it according to a pre-agreed ratio. If the original signal corresponding to the main pipe pressure is below the disconnection judgment range, exceeds the pressure transmitter's range, communication update times out, or engineering value conversion fails, the data validity check unit will mark the main pipe pressure as invalid.

[0040] When the main pipe pressure acquisition unit, main pipe flow acquisition unit, or pump set power acquisition unit uses a 4 to 20mA analog input, an input below 3.6mA is considered a disconnection, and an input above 21mA is considered an over-range input. When using a 0 to 10V analog input, an input below -0.1V or above 10.1V is considered an over-range input. When the analog input is within the nominal range, the data validity check unit performs engineering value conversion according to the linear relationship between the original input value and the engineering value. If the engineering value is expressed as... Represent the original input value as Let the lower limit and upper limit of the original input be represented as follows: and The lower limit and upper limit of the project value are expressed as follows: and The engineering value conversion can then be performed as follows: ,in, The engineering value representing the current control scan cycle can correspond to the main pipe pressure, main pipe flow rate, or pump set power consumption. This represents the original input value for controlling the current scan cycle; Indicates the lower limit of the original input; Indicates the upper limit of the original input; Indicates the lower limit of the engineering value; This represents the upper limit of the project value. The above formula is applicable under the following conditions: .like If any range parameter is not configured, the engineering value conversion fails, and the data validity check unit marks the corresponding operating quantity as invalid.

[0041] When any acquisition component or frequency converter 200 provides operating data via communication register, the data validity check unit reads the communication quality bit and update timestamp. If the communication quality bit is invalid, or if no new update timestamp is received for three consecutive control scan cycles, a communication interruption is determined. For the pump operating frequency, if the pump operating frequency returned by the frequency converter 200 feedback interface is less than 0Hz or greater than the maximum allowable output frequency of the frequency converter 200, the data validity check unit marks the pump operating frequency as out of range. If any of the above-mentioned disconnection, out-of-range, or communication interruption determination results are met, the pump pipe response reversal point confirmation unit 140 is prohibited from confirming the pump pipe response reversal point.

[0042] For the main pipe flow rate, the data validity check unit can perform engineering value conversion based on the flow meter output signal. If the original signal corresponding to the main pipe flow rate is below the disconnection judgment range, exceeds the flow meter range, communication update times out, or engineering value conversion fails, the data validity check unit will mark the main pipe flow rate as invalid. Since the reversal flag generation unit 130 needs to determine whether the main pipe flow rate has increased, if the main pipe flow rate is invalid and comparison continues, invalid data may be treated as no increase in the main pipe flow rate. Therefore, it is necessary to prohibit the confirmation of the pump pipe response reversal point.

[0043] For the power consumption of the pump set, the data validity check unit can read the active power data of the pump set's power meter. If the communication of the pump set's power meter is interrupted, the engineering value conversion is invalid, or the power consumption of the pump set exceeds the meter's range, the data validity check unit will mark the power consumption of the pump set as invalid. The power consumption of the pump set is used to confirm that the energy input increases with the increase of the pump's operating frequency. If this data is invalid, the reverse flag generation unit 130 cannot distinguish between the situation where the frequency command has not been executed and the situation where the currently operating pump has actually increased its power input.

[0044] For the pump operating frequency, the data validity check unit can read the feedback interface of the frequency converter 200. If the frequency converter 200 communication is interrupted, the feedback interface is not updated, the feedback data exceeds the allowable frequency range of the frequency converter 200, or the engineering value conversion fails, the data validity check unit will mark the pump operating frequency as invalid. The pump operating frequency is used to confirm that the frequency converter 200 is in frequency increase operation and that the currently running pump is actually increasing its frequency. If this data is invalid, the reversal flag generation unit 130 cannot confirm the direction of the control action.

[0045] When the main pipe pressure, main pipe flow rate, pump set power consumption, and pump operating frequency are all valid, the data validity check unit allows the reversal flag generation unit 130 to perform adjacent control scan cycle comparisons. When any data is disconnected, exceeds the range, or is interrupted, the data validity check unit prohibits the confirmation of the pump pipe response reversal point and sends the corresponding invalid status to the alarm and protection coordination unit and the monitoring display and record recovery unit.

[0046] Furthermore, the detailed implementation of the flag generation unit is as follows: The reversal flag generation unit 130 is used to identify the combined state of pump operating frequency increase, pump power consumption increase, and main pipe pressure and main pipe flow not increase in adjacent control scan cycles when the same operating pump combination, the same valve in position and the frequency converter is in frequency increase operation, and generate a reversal flag.

[0047] The "same operating pump combination" is used to define a water supply pump set that remains unchanged during adjacent control scan cycles. If a standby pump is engaged, the currently operating pump is deactivated, or the pump combination changes between adjacent control scan cycles, the changes in the main pipe pressure and flow rate may originate from the change in the pump combination. In this state, the reverse flag generation unit 130 should not confirm the output response of the currently operating pump after frequency increase. The PLC control cabinet 100 can confirm the same operating pump combination based on the operation feedback, the inverter operation feedback status, and the status bit of the standby pump control unit 160.

[0048] The same valve position status is used to define that the valve position related to the water output of the variable frequency pump set 300 has not changed in adjacent control scan cycles. If the valve position status changes, the main pipe pressure and main pipe flow may be caused by changes in valve opening, rather than changes in pump operating frequency and pump set power consumption. The PLC control cabinet 100 can confirm that the valve is in a predetermined position through the valve position status. Only when the same valve position status is established will the reverse flag generation unit 130 perform the four-item sequence relationship identification.

[0049] The inverter is in frequency ramping mode to limit the current control direction to increasing water supply output. The inverter being in frequency ramping mode can be confirmed by an increase in inverter frequency command output from the inverter voltage regulator unit 150 with a reverse branch, an increase in the water pump operating frequency fed back by the inverter 200, or both. To more reliably confirm the actual execution result, this embodiment uses the increase in water pump operating frequency as one of four sequential relationships.

[0050] To enable the pre-gating conditions of the reverse flag generation unit 130 to be directly written into the PLC program, this embodiment converts the same running pump combination, the same valve position status, and the frequency converter being in frequency boosting operation into status word comparisons. The running pump combination status word records the set of pump numbers whose operation feedback is established in the current control scan cycle; the valve position status word records the set of valve position statuses of the outlet valve corresponding to the currently running pump; the frequency converter frequency command represents the command value output by the frequency converter voltage regulator unit 150 with reverse branch to the frequency converter 200 in the current control scan cycle. If the running pump combination status word is represented as... The valve position status is represented as The frequency command of the inverter is represented as Then the pre-gating condition is: ,in, Indicates the first The pre-gating condition for each control scan cycle can be either true or false. Indicates the first The combined status word of the operating pump for each control scan cycle; This indicates the running pump combination status word saved in the previous control scan cycle; Indicates the first The valve position status word for each control scan cycle; This indicates the valve position status word saved in the previous control scan cycle; Indicates the first A frequency command for controlling the frequency of the inverter during a scan cycle; This indicates the inverter frequency command saved in the previous control scan cycle; and They represent the first The pump operating frequency is saved in each control scan cycle and the previous control scan cycle. Only When established, the reverse flag generation unit 130 continues to determine the sequential relationship between the pump group's power consumption, the main pipe pressure, and the main pipe flow rate.

[0051] Under the aforementioned pre-gating conditions, the determination of the reversing flag of the reversing flag generation unit 130 is as follows: Among these, the increase in pump operating frequency, the increase in pump set power consumption, and the fact that the main pipe pressure and main pipe flow rate did not increase are only considered as factors in this analysis. Furthermore, the data validation check unit allows for sub-conditions after the judgment; when Or, if any running quantity is invalid, the reverse flag generation unit 130 outputs... The determination of the reverse direction is not confirmed.

[0052] in, Indicates the first The value of the reversal flag for each control scan cycle is calculated by the reversal flag generation unit 130. Indicates the first Pre-gating conditions for each control scan cycle; Indicates the first The power consumption of the pump unit in each control scan cycle is obtained from the pump unit power meter. This indicates the power consumption of the pump unit saved in the previous control scan cycle; Indicates the first The total pressure of each control scan cycle is obtained from the pressure transmitter on the common outlet main pipe 400; This indicates the total tube pressure stored in the previous control scan cycle; Indicates the first The total flow rate of each control scan cycle is taken from the flow meter on the common outlet main pipe 400; This indicates the total tube flow rate saved in the previous control scan cycle. In and still respectively represent the first The pump operating frequency is saved in each control scan cycle and the previous control scan cycle.

[0053] in, This is used to confirm that the water pump operating frequency has increased, indicating that the actual output frequency fed back by the frequency converter 200 has changed in the direction of frequency increase. This is used to confirm that the power consumption of the pump set has increased, indicating that the energy input of the variable frequency pump set 300 has increased. This is used to confirm that the main pipe pressure has not increased, indicating that the pressure output on the common outlet main pipe 400 has not improved with the frequency increase action; This is used to confirm that the flow rate in the main pipe has not increased, indicating that the flow output on the common outlet main pipe 400 has not improved with the frequency increase action.

[0054] Only when both the pump operating frequency and the pump set power consumption increase simultaneously can it be indicated that the control direction and energy input of the currently operating pump have changed towards increasing supply. Only when both the main pipe pressure and the main pipe flow rate do not increase simultaneously can it be indicated that the shared outlet main pipe 400 has not formed an effective increase in supply in either the pressure output or flow output direction. If the main pipe pressure does not increase but the main pipe flow rate increases, it may indicate that changes in external water use have led to an increase in flow rate; if the main pipe flow rate does not increase but the main pipe pressure increases, it may indicate changes in network resistance or changes in water demand. The reversal flag generation unit 130 requires that both outputs not increase, which can reduce misjudgments caused by a single output value.

[0055] Furthermore, the detailed implementation of the pump pipe response reversal point confirmation unit is as follows: The pump pipe response reversal point confirmation unit 140 is used to confirm the pump pipe response reversal point when the reversal flag is established for two consecutive control scan cycles. The pump pipe response reversal point is not a single limit exceeding point of the main pipe pressure, main pipe flow rate, pump set power consumption, or pump operating frequency, but rather a control state confirmation point formed after the combined state of pump operating frequency increase, pump set power consumption increase, and main pipe pressure and flow rate not increase are established in consecutive control scan cycles.

[0056] The pump pipe response reversal point confirmation unit 140 can be implemented using a counter, a status latch, or a sequential control step. When the reversal flag output by the reversal flag generation unit 130 is at the [number]th [time], When the control scan cycle is in an established state, the pump tube response reversal point confirmation unit 140 increments the consecutive establishment count by one; when the reversal flag of the next control scan cycle is still in an established state, the consecutive establishment count reaches two control scan cycles, and the pump tube response reversal point confirmation unit 140 confirms the pump tube response reversal point. If the reversal flag of any control scan cycle is not established, the consecutive establishment count is reset to zero.

[0057] The requirement of two consecutive control scan cycles is used to suppress single-sample jitter. For example, a pressure transmitter or flow meter may experience a brief period of no increase in frequency within a single control scan cycle due to communication refresh, instantaneous fluctuations, or engineering value conversion errors. If the pump tube response reversal point is confirmed only based on a single control scan cycle, the variable frequency voltage regulator unit 150 with the reversal branch may prematurely stop superimposing the frequency increase increment. The pump tube response reversal point confirmation unit 140 confirms the response through two consecutive control scan cycles, requiring the combined state to have minimum continuity.

[0058] After the pump pipe response reversal point confirmation unit 140 outputs the pump pipe response reversal point, the variable frequency voltage regulator unit 150 with reversal branch enters the reversal branch. This output can be a Boolean status bit in the PLC control cabinet 100 or a status step in sequential control. When outputting the pump pipe response reversal point, the pump pipe response reversal point confirmation unit 140 can also send the control scan cycle number where the confirmation occurred, the valid frequency command corresponding to the previous control scan cycle, the main pipe pressure, the main pipe flow rate, the power consumption of the pump group, and the pump operating frequency to the alarm and protection coordination unit and the monitoring display and record recovery unit.

[0059] The prerequisites for the pump pipe response reversal point confirmation unit 140 to confirm the pump pipe response reversal point still include the same operating pump combination, the same valve in position, the frequency converter being in frequency boosting operation, and the data validity check unit not prohibiting confirmation. If the standby pump control unit 160 has issued a standby pump start command, or the operation feedback shows that the operating pump combination has changed, the pump pipe response reversal point confirmation unit 140 should restart the continuous establishment judgment, instead of using the reversal mark before the change.

[0060] The pump pipe response reversal point confirmation unit 140 can also be configured with release conditions. When the reversal flag is no longer valid and the main pipe pressure returns to the target pressure range, the pump pipe response reversal point confirmation information is cleared. After the pump pipe response reversal point confirmation information is cleared, the monitoring display and recording recovery unit rechecks the operating permission, and the variable frequency voltage regulator unit 150 with the reversal branch resumes variable frequency voltage regulation control that outputs the inverter frequency command with the main pipe pressure as the feedback quantity and the target pressure as the setpoint.

[0061] Furthermore, a detailed implementation of the variable frequency voltage regulator unit with reverse branch is as follows: The variable frequency voltage regulator unit 150 with reverse branch is used to output the frequency converter command with the main pipe pressure as the feedback quantity and the target pressure as the setpoint when the reverse point of the pump pipe response is not confirmed. At this time, the variable frequency voltage regulator unit 150 with reverse branch can use the existing PID function block or equivalent closed-loop control logic in the PLC control cabinet 100.

[0062] The valid frequency command is the frequency command that has been output to the frequency converter 200. The valid frequency command is not an internally calculated value that has not yet been sent, but rather a frequency converter frequency command that has been output by the variable frequency voltage regulator unit 150 with reverse branch and recorded by the PLC control cabinet 100. The valid frequency command corresponding to the control scan cycle preceding the pump tube response reverse point confirmation is the last frequency converter frequency command considered retainable before the pump tube response reverse point confirmation.

[0063] After confirming the pump pipe response reversal point, the variable frequency voltage regulator unit 150 with the reversal branch stops adding frequency increments to the frequency converter command and maintains the frequency converter command at the effective frequency command corresponding to the control scan cycle preceding the confirmed pump pipe response reversal point. Stopping the addition of frequency increments means that the variable frequency voltage regulator unit 150 with the reversal branch no longer increases the frequency converter command for the currently operating pump based on the low mains pressure. Maintaining the effective frequency command means that the frequency converter 200 continues to operate the currently running pump at this effective frequency command, avoiding further fluctuations in the mains pressure caused by sudden pump stoppage or significant frequency reduction.

[0064] After confirming the reversal point of the pump pipe response, the variable frequency voltage regulator unit 150 with a reversal branch prohibits the currently operating pump from continuing to increase its frequency until the reversal flag is no longer valid and the main pipe pressure returns to the target pressure range. This prohibition on further frequency increases can be achieved by freezing the frequency increase output channel corresponding to the currently operating pump, blocking the positive frequency increment, limiting the frequency increase direction output of the PID function block, or keeping the frequency command of the inverter corresponding to the currently operating pump as a valid frequency command. Regardless of the PLC implementation method used, it should be ensured that the currently operating pump will not continue to increase its frequency due to low main pipe pressure before the reversal state is lifted.

[0065] After confirming the reversal point of the pump pipe response, the variable frequency pressure regulating unit 150 with the reversing branch also needs to determine whether the main pipe pressure is lower than the lower limit of the target pressure range. If the main pipe pressure is lower than the lower limit of the target pressure range, it means that simply maintaining the effective frequency command is insufficient to meet the water supply pressure demand. At this time, the variable frequency pressure regulating unit 150 with the reversing branch sends a standby pump request to the standby pump control unit 160. If the main pipe pressure is not lower than the lower limit of the target pressure range, the variable frequency pressure regulating unit 150 with the reversing branch can maintain the effective frequency command and wait for the reversal flag to no longer be valid and the main pipe pressure to return to the target pressure range.

[0066] After the standby pump control unit 160 responds to the standby pump request and controls the standby pump to start, the variable frequency voltage regulator unit 150 with reverse branch no longer uses the individual frequency increase of the currently operating pump as the only means of increasing power supply. Instead, it continues to perform variable frequency voltage regulation control with the new combination of operating pumps. After the standby pump is started and confirmed by the operation feedback, the total pipe pressure and total pipe flow may generate new responses. The variable frequency voltage regulator unit 150 with reverse branch can re-execute variable frequency voltage regulation control with the total pipe pressure as the feedback quantity and the target pressure as the setpoint, based on the new combination of operating pumps, using the variable frequency drive frequency command output by the frequency converter.

[0067] Once the reversal flag is no longer valid and the main pipe pressure returns to the target pressure range, the variable frequency voltage regulator unit 150 with the reversal branch resumes variable frequency voltage regulation control, using the main pipe pressure as feedback and the target pressure as setpoint to output the inverter frequency command. The reversal flag no longer valid in the recovery condition confirms that the pump operating frequency, pump set power consumption, main pipe pressure, and main pipe flow rate are no longer in a reversible state; the main pipe pressure returning to the target pressure range confirms that the water supply pressure of the shared outlet main pipe 400 has returned to the allowable range. Both conditions being met simultaneously prevent premature resumption of the current operating pump frequency increase before the pump pipe response reversal point is resolved.

[0068] Furthermore, the detailed implementation of the standby pump control unit and the pump valve sequential start-stop unit is as follows: The standby pump control unit 160 is used to respond to standby pump requests and control the standby pumps to be activated. After receiving a standby pump request from the variable frequency voltage regulator unit 150 with a reverse branch, the standby pump control unit 160 determines the number of standby pumps to be activated based on the total flow rate, and selects standby pumps from the available pumps based on operation feedback and fault feedback, and the pumps corresponding to the fault feedback are not included in the standby pump candidate set.

[0069] The number of standby pumps can be determined based on the total flow rate and the control rules for the number of conventional pump sets in the smart pump room. The total flow rate reflects the current water supply demand of the shared outlet main pipe 400. The standby pump control unit 160 can determine whether to activate one or more standby pumps based on the project scope of the total flow rate, the number of pumps already in operation, and the number of available pumps.

[0070] To ensure the number of standby pumps can be directly determined from the total flow rate, the standby pump control unit 160 can first determine the target number of operating pumps based on the total flow rate and the rated flow rate of each pump, and then determine the number of standby pumps to be activated based on the difference between the target number of operating pumps and the number of pumps already in operation. If the target number of operating pumps is expressed as... The maximum number of pumps allowed to operate is expressed as The number of pumps already in operation is expressed as Express the total pipe flow as The rated flow rate of a single pump is expressed as The target number of operating pumps is: ,in, Indicates the target number of pumps in operation; This indicates the maximum number of pumps that can be operated, and the value is derived from the existing pump group control parameter in PLC control cabinet 100. This indicates the number of pumps that are in operation, and the value is derived from the number of pumps whose operation feedback is valid. Indicates the total flow rate; This indicates the rated flow rate of a single pump, and the value is derived from the pump nameplate, equipment ledger, or existing pump set number control parameters in the 300 variable frequency pump set. Indicates not less than The smallest integer. and Using the same flow rate unit, the ratio of the two is dimensionless. The above formula is applicable under the following conditions: And the pumps in the standby pump candidate set all have the same single-pump rated flow rate; if If the rated flow rate of a single pump is not configured, the calculation of the number of standby pumps to be put into operation will be marked as invalid.

[0071] If the rated flow rates of the pumps in the candidate set of standby pumps are different, the standby pump control unit 160 reads the rated flow rates of each pump in the running pump and the candidate set of standby pumps according to the existing pump group sorting rules. It first calculates the sum of the rated flow rates of the pumps whose operation feedback is valid, and then adds them to the candidate set of standby pumps one by one according to the existing pump group sorting rules, until the sum of the rated flow rates of the running pumps and the pumps to be added is not less than the total pipe flow rate, or all available standby pumps have been added. The number of pumps determined in this way is the number of standby pumps to be added.

[0072] If the number of standby pumps is expressed as The number of available standby pumps is expressed as The number of standby pumps put into operation is: ,in, Indicates the number of standby pumps in operation; This indicates the number of available standby pumps, and the value is the number of pumps that have no fault feedback and are not in a state where the operation feedback is established. Indicates the target number of pumps in operation; Indicates the number of pumps currently in operation. The standby pump control unit 160 is configured according to... Select a standby pump from the available pumps, and ensure that the pump corresponding to the fault feedback is not added to the standby pump candidate set. If The standby pump control unit 160 does not output new standby pump activation commands, but only maintains the standby pump request record and alarm status.

[0073] The standby pump control unit 160 confirms which pumps are already in operation based on operational feedback and removes pumps corresponding to fault feedback. Pumps with fault feedback are not included in the standby pump candidate set, preventing pumps with faulty states from being mistakenly activated. If multiple available pumps exist, the standby pump control unit 160 can determine the standby pump based on cumulative operating time, primary / standby rotation order, or existing pump group sorting rules.

[0074] The pump and valve sequential start / stop unit is located within the PLC control cabinet 100. It checks the water tank level permit status, emergency stop reset status, inverter readiness status, valve position status, and fault feedback before starting the standby pump. It confirms the standby pump's activation only after all valve position status, inverter operation feedback status, and operation feedback are verified. The pump and valve sequential start / stop unit works in conjunction with the standby pump control unit 160 to ensure that standby pump requests do not exceed the normal safety permitting limits.

[0075] Before starting the standby pump, the pump and valve sequential start / stop unit first checks the water level in the tank. If the water level does not meet the requirements, it indicates that the water tank does not have the basic water supply conditions for starting the standby pump, and the pump and valve sequential start / stop unit prohibits the standby pump from starting. Next, it checks the emergency stop reset status. If the emergency stop reset status is not met, the PLC control cabinet 100 keeps the standby pump stopped. Then, it checks the inverter's readiness status and fault feedback. If the inverter 200 is not ready or the fault feedback indicates a fault in the corresponding pump or drive, the pump will not enter the start-up process.

[0076] Once the aforementioned operational permissions are met, the pump-valve sequential start-stop unit can open the corresponding valve of the standby pump according to the on-site equipment sequence control requirements, and wait for the valve to be in position. After the valve is in position, the inverter 200 enters the operating state and waits for the inverter operating feedback state to be established. After the inverter operating feedback state is established, it continues to wait for the corresponding operating feedback of the standby pump to be established. Only after the valve is in position, the inverter operating feedback state, and the operating feedback are all established will the pump-valve sequential start-stop unit confirm the standby pump's activation.

[0077] If any step during the standby pump startup process fails to be completed within the time allowed by the normal equipment, the pump valve sequence start / stop unit can suspend subsequent actions and send the status to the alarm and protection coordination unit. If the standby pump is unavailable, the variable frequency voltage regulator unit 150 with reverse branch maintains the effective frequency command to avoid continuing to add frequency increments to the currently operating pump, and waits for on-site handling or other available water pumps to meet the startup conditions.

[0078] Furthermore, the detailed implementation of the alarm and protection coordination unit is as follows: The alarm and protection coordination unit is located in the PLC control cabinet 100. It is used to record the main pipe pressure, main pipe flow, pump group power consumption and water pump operating frequency when the pump pipe response reversal point is confirmed, generate frequency increase loss and no supply alarm, and stop the corresponding water pump and lock its automatic restart when the water tank water level does not meet the permissible state, the fault feedback indicates that the frequency converter is faulty or overloaded, or the operation feedback is lost.

[0079] When the pump pipe response reversal point confirmation unit 140 confirms the pump pipe response reversal point, the alarm and protection coordination unit reads and saves the main pipe pressure, main pipe flow rate, pump set power consumption, and pump operating frequency for that control scan cycle. Saving these operating values ​​allows field operators to see evidence that the frequency increase action has occurred, the pump set power consumption has increased, but the output of the shared outlet main pipe 400 has not improved. The frequency increase with loss and no power supply alarm is used to indicate that the current control branch has entered the reversal process.

[0080] The alarm and protection coordination unit has a priority relationship with conventional safety protection. If only the pump pipe response reversal point is confirmed, and the water tank level permit status, fault feedback, and operation feedback do not trigger conventional fault protection, the alarm and protection coordination unit will generate an up-frequency lossy no-supply alarm. The currently operating pump can be listed as an object to be inspected, but it will not be directly shut down. If the water tank level permit status is not met, the fault feedback indicates a frequency converter fault or overload, or the operation feedback is lost, the alarm and protection coordination unit will shut down the corresponding water pump and lock its automatic restart.

[0081] The corresponding water pump is shut down when the water level in the tank does not meet the permissible condition to prevent the variable frequency pump set 300 from continuing to operate when the water supply side is insufficient. The corresponding water pump is shut down when the frequency converter 200 fails or is overloaded, to prevent the frequency converter 200 or the water pump from continuing to be automatically controlled in a faulty state. The corresponding water pump is shut down when operational feedback is lost because the PLC control cabinet 100 cannot confirm the actual operating status of the water pump; continuing to keep the water pump in the automatic candidate state may cause the standby pump control unit 160 to incorrectly determine the operating pump combination.

[0082] The frequency-increased lossy no-supply alarm generated by the alarm and protection coordination unit can be displayed and saved by the monitoring display and recording recovery unit. The alarm information may include the pump pipe response reversal point confirmation time, the corresponding water pump number, the main pipe pressure, the main pipe flow rate, the power consumption of the pump set, the water pump operating frequency, the effective frequency command, and the standby pump request status.

[0083] Further detailed implementation of the monitoring display and recording recovery unit is as follows: The monitoring, display, recording, and recovery unit is located within the PLC control cabinet 100, or it can be implemented jointly by the PLC control cabinet 100, the field touch screen, and the upper-level monitoring terminal. The monitoring, display, recording, and recovery unit displays and saves pump pipe response reversal point confirmation information, alarm information, and operation permit-related status, and re-checks the operation permit after the pump pipe response reversal point confirmation information is cleared.

[0084] The monitoring, display, and recording recovery unit can display the status information of the PLC control cabinet 100, target pressure management unit 110, operating quantity acquisition unit 120, reversal flag generation unit 130, pump pipe response reversal point confirmation unit 140, variable frequency voltage stabilizing unit with reversal branch 150, standby pump control unit 160, frequency converter 200, variable frequency pump set 300, and common outlet main pipe 400. The displayed content may include main pipe pressure, main pipe flow rate, pump set power consumption, pump operating frequency, target pressure, target pressure range, reversal flag, pump pipe response reversal point confirmation information, effective frequency command, standby pump request, operating feedback, fault feedback, water tank water level permitting status, emergency stop reset status, frequency converter ready status, valve in position status, and frequency converter operating feedback status.

[0085] When the monitoring, display, recording, and recovery unit saves the pump pipe response reversal point confirmation information, it can use event logging to save the confirmation time, relevant operating quantities, and control output status. When the monitoring, display, recording, and recovery unit saves the operating permit-related status, it can save it at a fixed period or save event records when the operating permit changes.

[0086] Once the reversal flag is no longer valid and the main pipe pressure returns to the target pressure range, the pump pipe response reversal point confirmation information is cleared. After the pump pipe response reversal point confirmation information is cleared, the monitoring display and recording recovery unit rechecks the operating permits. The recheck of operating permits includes at least the water tank water level permit status, emergency stop reset status, inverter ready status, valve position status, operating feedback, and fault feedback. Once all operating permits are satisfied, the PLC control cabinet 100 allows the relevant water pump to re-enter the automatic control candidate state.

[0087] The monitoring, display, and recording recovery unit can also display and record remote commands. The remote terminal can only issue start / stop, mode switching, and target pressure commands when local remote authorization is valid. Before executing remote commands, the PLC control cabinet 100 still verifies the operation authorization and interlocking rules according to the same rules as the field automatic control. Field emergency stops and field controls take precedence over remote commands.

[0088] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and all such modifications and variations fall within the scope defined by the appended claims.

Claims

1. A control system for a smart pumping station, comprising a PLC control cabinet, a frequency converter, a frequency converter pump set, a common outlet main pipe, and an operating data acquisition unit, wherein the frequency converter pump set includes currently operating pumps and standby pumps, and the outlets of each pump converge into the common outlet main pipe, characterized in that, The PLC control cabinet includes a target pressure management unit, a reversal flag generation unit, a pump pipe response reversal point confirmation unit, a frequency converter voltage regulator unit with reversal branches, and a standby pump control unit. The target pressure management unit stores the target pressure and forms a target pressure range with a lower limit boundary; The operation data acquisition unit acquires the main pipe pressure, main pipe flow rate, pump set power consumption and pump operating frequency in the same control scan cycle, and saves the above operation data corresponding to adjacent control scan cycles; The reversal flag generation unit identifies the combined state of pump operating frequency increase, pump group power consumption increase, and main pipe pressure and main pipe flow not increase in adjacent control scan cycles when the same operating pump combination, the same valve in position and the frequency converter is in frequency increase operation, and generates a reversal flag. The pump tube response reversal point confirmation unit confirms the pump tube response reversal point when the reversal flag is set for two consecutive control scan cycles. After confirming the pump tube response reversal point, the variable frequency voltage regulator unit with reversal branch stops adding frequency increment to the frequency converter frequency command, keeps the frequency converter frequency command at the effective frequency command corresponding to the control scan cycle before confirming the pump tube response reversal point, and issues a standby pump request when the main pipe pressure is lower than the lower limit boundary of the target pressure range. The standby pump control unit responds to standby pump requests and controls the standby pump to be activated.

2. The control system for a smart pumping station according to claim 1, characterized in that, The operating data acquisition unit includes a main pipe pressure acquisition component, a main pipe flow acquisition component, a pump set power consumption acquisition component, and a pump operating frequency acquisition component. The main pipe pressure acquisition component is a pressure transmitter installed in the common outlet main pipe, the main pipe flow acquisition component is a flow meter installed in the common outlet main pipe, the pump set power consumption acquisition component is a pump set power meter, and the pump operating frequency acquisition component is the feedback interface of the frequency converter.

3. The control system for a smart pumping station according to claim 1, characterized in that, The PLC control cabinet also includes a data validity check unit. The data validity check unit performs engineering value conversion on the main pipe pressure, the main pipe flow rate, the power consumption of the pump group and the operating frequency of the water pump, and prohibits the confirmation of the pump pipe response reversal point when any data has a disconnection, over-range, or communication interruption.

4. The control system for a smart pumping station according to claim 1, characterized in that, When the reverse branch of the variable frequency voltage regulator unit is not confirmed, it outputs the frequency converter frequency command with the main pipe pressure as the feedback quantity and the target pressure as the given quantity. The effective frequency command is the frequency converter frequency command that has been output to the frequency converter.

5. The control system for a smart pumping station according to claim 1, characterized in that, After confirming the reversal point of the pump pipe response, the variable frequency voltage regulator unit with reversing branch prohibits the currently running pump from continuing to increase its frequency until the reversal flag is no longer valid and the main pipe pressure returns to the target pressure range. After the reversal flag is no longer valid and the main pipe pressure returns to the target pressure range, the variable frequency voltage regulator unit resumes variable frequency voltage regulation control that outputs the frequency converter frequency command with the main pipe pressure as the feedback quantity and the target pressure as the setpoint.

6. The control system for a smart pumping station according to claim 1, characterized in that, The standby pump control unit determines the number of standby pumps to be put into operation based on the total pipeline flow rate, and selects the standby pumps from the available water pumps based on operation feedback and fault feedback, and the water pump corresponding to the fault feedback is not included in the standby pump candidate set.

7. The control system for a smart pumping station according to claim 6, characterized in that, The PLC control cabinet also includes a pump and valve sequential start-stop unit. Before starting the standby pump, the pump and valve sequential start-stop unit checks the water level permit status, emergency stop reset status, inverter ready status, valve position status, and fault feedback. After the valve position status, inverter operation feedback status, and operation feedback are all established, the standby pump is confirmed to be put into operation.

8. The control system for a smart pumping station according to claim 1, characterized in that, The PLC control cabinet also includes an alarm and protection coordination unit. When the pump pipe response reversal point is confirmed, the alarm and protection coordination unit records the main pipe pressure, the main pipe flow rate, the power consumption of the pump group and the operating frequency of the water pump, generates an alarm for frequency increase with loss and no power supply, and stops the corresponding water pump and locks its automatic restart when the water level in the water tank does not meet the permissible state, the fault feedback indicates that the frequency converter is faulty or overloaded, or the operation feedback is lost.

9. The control system for a smart pumping station according to claim 1, characterized in that, The PLC control cabinet also includes a monitoring, display, and recording recovery unit. The monitoring, display, and recording recovery unit displays and saves the pump pipe response reversal point confirmation information, alarm information, and operation permit related status, and re-checks the operation permit after the pump pipe response reversal point confirmation information is cleared.

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