Sewage pump intelligent control system and control method thereof

Abstract

The invention discloses a sewage pump intelligent control system and a control method thereof. The system comprises a main control board, an HMI control panel, a motor protection unit, a dual-mode liquid level detection unit and a fault prompt unit. The HMI control panel comprises a wireless communication module and a key module which are independent of the main control board; the main control board is manually controlled through the key module; remote control is carried out through the wireless communication module; the motor protection unit collects key electrical parameters of a motor in the sewage pump in real time; the dual-mode liquid level detection unit acquires a first liquid level signal according to a main detection mode and acquires a second liquid level signal according to a standby detection mode; the main control board judges whether a fault occurs or not according to the key electric parameters, the first liquid level signal or the second liquid level signal; and the fault prompting module sends out a fault prompting signal when judging that a fault occurs. Comprehensive intelligent and automatic control over the sewage pump is achieved, the design is compact, the cost is controllable, the functions are comprehensive, and multimode remote monitoring is supported.

Description

Technical Field

[0001] This invention relates to the field of sewage pump control technology, specifically to an intelligent control system and control method for a sewage pump. Background Technology

[0002] With the accelerating pace of urbanization, the demand for wastewater treatment is surging, and the application scenarios for wastewater pumps are continuously expanding. Against this backdrop, "smart water management" has become the mainstream direction of industry development, and achieving intelligent control of wastewater pumps is an inevitable trend in equipment upgrades.

[0003] However, current sewage pump control products on the market have significant limitations, making it difficult to meet the needs of intelligent and efficient operation and maintenance. Specifically: (1) Traditional control products have limited functions: Most traditional sewage pump control boxes only have basic start-stop, liquid level triggering and simple protection functions, and lack accurate motor status monitoring (such as overload, overheating, voltage abnormality), accurate liquid level detection and fault warning and recording capabilities. When potential faults occur in the equipment, there is no early warning, which often leads to sudden pump shutdown, passive maintenance and high costs.

[0004] (2) Existing smart products have low integration, large size and high cost: Some controllers with advanced functions (such as networking and multi-parameter monitoring) often adopt a design that integrates all functional circuits on a single PCB board. This design results in a large controller size, which is difficult to install in compact sewage pumps or control boxes with strict space requirements. At the same time, the complex integration design also increases manufacturing costs.

[0005] (3) Lack of effective networking and centralized management capabilities: Many products do not have remote communication interfaces or only support a single communication method, making it impossible to integrate into the Internet of Things cloud platform. This forces maintenance personnel to be on-site to operate equipment, check parameters, or troubleshoot faults, resulting in low maintenance efficiency, high management costs, and difficulty in achieving centralized monitoring and intelligent management of multiple devices.

[0006] Therefore, there is an urgent need for a compact, cost-effective, fully functional, and remotely monitored intelligent sewage pump control product to solve the above-mentioned technical problems and facilitate the intelligent upgrading of sewage treatment equipment. Summary of the Invention

[0007] In view of this, the present invention provides an intelligent control system and control method for sewage pumps to solve the problems of single function, low integration, large product size, high cost, lack of integrated management capabilities and low operation and maintenance efficiency in existing sewage control technologies.

[0008] This invention provides an intelligent control system for a sewage pump, the system comprising a main control board, an HMI control panel, a motor protection unit, a dual-mode liquid level detection unit, and a fault indication unit; The HMI control panel includes a wireless communication module and a button module that are independent of the main control board; wherein, the wireless communication module is communicatively connected to the main control board, and the button module is electrically connected to the main control board; the motor protection unit, the dual-mode liquid level detection unit, and the fault indication unit are all electrically connected to the main control board; The main control board is used to receive user commands through the button module in the HMI control panel to manually control the sewage pump; it is also used to communicate wirelessly with a remote terminal through the wireless communication module to receive remote commands from the remote terminal to remotely control the sewage pump. The motor protection unit is used to collect key electrical parameters of the motor configured in the sewage pump in real time when the main control board controls the sewage pump, and transmit the collected key electrical parameters to the main control board in real time. The dual-mode liquid level detection unit has a main detection mode and a backup detection mode. When the main control board controls the sewage pump, it acquires a first liquid level signal from the sewage pump according to the main detection mode and transmits the first liquid level signal to the main control board. It is also used when the main control board controls the sewage pump, it acquires a second liquid level signal from the sewage pump according to the backup detection mode and transmits the second liquid level signal to the main control board. The first liquid level signal and the second liquid level signal are different. The main control board is also used to receive the key electrical parameters transmitted by the motor protection unit, and determine whether the sewage pump has a motor failure based on the key electrical parameters; it is also used to receive the first liquid level signal or the second liquid level signal transmitted by the dual-mode liquid level detection unit, and determine whether the sewage pump has a liquid level failure based on the first liquid level signal or the second liquid level signal. The fault indication module is used to issue a fault indication signal when the main control board determines that the sewage pump has a motor fault and / or a liquid level fault.

[0009] Optionally, the motor in the sewage pump is provided with a motor power supply circuit, and the key electrical parameters include the motor phase current signal and the motor phase voltage signal in the motor power supply circuit; The motor protection unit includes a phase current detection circuit and a phase voltage detection circuit. The input terminals of the phase current detection circuit and the phase voltage detection circuit are both electrically connected to the motor power supply circuit. The output terminals of the phase current detection circuit and the phase voltage detection circuit are both electrically connected to the input terminal of the main control board. The phase current detection circuit is used to collect the motor phase current signal in the motor power supply circuit and transmit the motor phase current signal to the main control board; The phase voltage detection circuit is used to collect the motor phase voltage signal in the motor power supply circuit and transmit the motor phase voltage signal to the main control board.

[0010] Optionally, the phase current detection circuit includes a current transformer U11, a first operational amplifier U12A, a first diode bridge rectifier, a first electrolytic capacitor C30, a first capacitor C7, a first resistor R5, a second resistor R6, a third resistor R7, a fourth resistor R37, a fifth resistor R38, and a sixth resistor R103. The primary side of current transformer U11 is electrically connected to one phase line of the motor power supply circuit, and the secondary side of current transformer U11 is electrically connected to the input terminal of the first diode bridge rectifier. The negative terminal of the output terminal of the first diode bridge rectifier is grounded. The positive terminal of the output terminal of the first diode bridge rectifier is electrically connected to the non-inverting input pin of the first operational amplifier U12A through the first resistor R5. The positive terminal of the first electrolytic capacitor C30 and the first terminal of the sixth resistor R103 are both connected to the common connection terminal between the positive terminal of the output terminal of the first diode bridge rectifier and the first resistor R5. The negative terminal of the first electrolytic capacitor C30 and the second terminal of the sixth resistor R103 are both grounded. The first terminal of the fourth resistor R37 is connected to the first... A resistor R5 is connected to the common connection between the non-inverting input pin of the first operational amplifier U12A, and the second end of the fourth resistor R37 is grounded; the power supply pin of the first operational amplifier U12A is electrically connected to the circuit power supply terminal, and the sibling pins of the first operational amplifier U12A are grounded; the inverting input pin of the first operational amplifier U12A is grounded through the third resistor R7, and is also electrically connected to the output pin of the first operational amplifier U12A through the fifth resistor R38; the output pin of the first operational amplifier U12A is electrically connected to the input terminal of the main control board through the second resistor R6; the first end of the first capacitor C7 is connected to the common connection between the second resistor R6 and the input terminal of the main control board, and the second end of the first capacitor C7 is grounded.

[0011] Optionally, the phase voltage detection circuit includes a transformer U13, a second operational amplifier U14A, a second diode bridge rectifier, a second electrolytic capacitor C31, a second capacitor C5, a third capacitor C6, a seventh resistor R1, an eighth resistor R2, a ninth resistor R3, a tenth resistor R4, an eleventh resistor R34, a twelfth resistor R36, and a thirteenth resistor R99. The first terminal of the primary side of transformer U13 is electrically connected to one phase line of the motor power supply circuit through the thirteenth resistor R33, and the second terminal of the primary side of transformer U13 is electrically connected to the reference point of the motor power supply circuit; the secondary side of transformer U13 is electrically connected to the input terminal of the second diode bridge rectifier; the negative terminal of the output terminal of the second diode bridge rectifier is grounded; the positive terminal of the output terminal of the second diode bridge rectifier is electrically connected to the non-inverting input pin of the second operational amplifier U14A through the seventh resistor R1; the positive terminal of the second electrolytic capacitor C31 and the first terminal of the eighth resistor R2 are both connected to the common connection terminal between the positive terminal of the output terminal of the second diode bridge rectifier and the seventh resistor R1; the negative terminal of the second electrolytic capacitor C31 and the second terminal of the eighth resistor R2 are both grounded; the first terminal of the eleventh resistor R34 is connected to the seventh resistor R1. The second end of the eleventh resistor R34 is grounded on the common connection terminal between the non-inverting input pin of the second operational amplifier U14A and the common connection terminal between the non-inverting input pin of the second operational amplifier U14A and the 5V power supply terminal. The ground pin of the second operational amplifier U14A is grounded. The inverting input pin of the second operational amplifier U14A is grounded through the tenth resistor R4 and is also electrically connected to the output pin of the second operational amplifier U14A through the twelfth resistor R36. The output pin of the second operational amplifier U14A is electrically connected to the input terminal of the main control board through the ninth resistor R3. The first end of the second capacitor C5 is connected to the common connection terminal between the ninth resistor R3 and the input terminal of the main control board, and the second end of the second capacitor C5 is grounded.

[0012] Optionally, the key electrical parameters also include a temperature detection signal for characterizing the motor temperature; The motor protection unit also includes a motor overheat detection circuit, the output of which is electrically connected to the input of the main control board. The motor overheat detection circuit is used to collect temperature detection signals from the motor and transmit the temperature detection signals to the main control board.

[0013] Optionally, the motor overheat detection circuit includes a temperature sensor, a first connector J12, a first optocoupler U15, a fourth capacitor C38, a fourteenth resistor R28, a fifteenth resistor R65, a sixteenth resistor R66, and a seventeenth resistor R67; the first connector J12 has two pins; the temperature sensor is located on the motor. The first and second pins of the first connector J12 are both electrically connected to the output terminal of the temperature sensor. The first pin of the first connector J12 is also electrically connected to the +12V power supply terminal through the fifteenth resistor R65. The second pin of the first connector J12 is also electrically connected to the positive input terminal of the first optocoupler U15. The first end of the fourth capacitor C38 and the first end of the sixteenth resistor R66 are both connected to the common connection terminal between the second pin of the first connector J12 and the positive input terminal of the first optocoupler U15. The second end of the fourth capacitor C38 and the second end of the sixteenth resistor R66 are both grounded. The negative input terminal of the first optocoupler U15 is grounded. The collector of the output side of the first optocoupler U15 is electrically connected to the +3.3V power supply terminal. The collector-emitter of the output side of the first optocoupler U15 is electrically connected to the input terminal of the main control board through the fourteenth resistor R28. The first end of the seventeenth resistor R67 is connected to the common connection terminal between the collector-emitter of the output side of the first optocoupler U15 and the fourteenth resistor R28. The second end of the seventeenth resistor R67 is grounded.

[0014] Optionally, the key electrical parameters also include the digital pulse signal generated when the power supply voltage in the motor power supply circuit crosses zero; The motor protection unit also includes two identical zero-crossing detection circuits. The input terminals of the two zero-crossing detection circuits are electrically connected to different phase lines of the motor power supply circuit, and the output terminals of the two zero-crossing detection circuits are electrically connected to the input terminal of the main control board. Each zero-crossing detection circuit is used to detect the digital pulse signal generated when the phase voltage in the corresponding phase line crosses zero, and transmits the digital pulse signal to the main control board. The main control board is used to compare the phase difference between the two received digital pulse signals and identify whether the motor power supply circuit is a single-phase power supply or a three-phase power supply based on the phase difference.

[0015] Optionally, each of the zero-crossing detection circuits includes a second optocoupler, a first diode, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, and a twenty-second resistor; In each of the zero-crossing detection circuits, the first end of the nineteenth resistor and the first end of the twenty-first resistor are both coupled to the phase line corresponding to the motor power supply circuit. The second end of the nineteenth resistor is connected to the positive input terminal of the second optocoupler through the twentieth resistor and the first diode in sequence. The second end of the twenty-first resistor is connected to the negative input terminal of the second optocoupler through the twenty-second resistor. The collector of the output side of the second optocoupler is connected to the input terminal of the main control board. The collector of the output side of the second optocoupler is also connected to the +3.3V power supply terminal through the eighteenth resistor. The emitter of the output side of the second optocoupler is grounded.

[0016] Optionally, the first liquid level signal is specifically an analog liquid level signal, and the second liquid level signal is specifically a digital liquid level signal; The dual-mode liquid level detection unit includes an analog liquid level detection circuit and a digital liquid level detection circuit, both of which are electrically connected to the input terminal of the main control board. The analog liquid level detection circuit is used to collect the analog liquid level signal of the sewage pump, and convert the analog liquid level signal into a liquid level voltage signal and transmit it to the main control board. The digital liquid level detection circuit is used to collect the digital liquid level signal of the sewage pump and transmit the digital liquid level signal to the main control board.

[0017] Optionally, the analog liquid level detection circuit includes a liquid level sensor, a second connector J7, a first common-mode inductor D28, a second common-mode inductor D29, a third operational amplifier U3B, a fifth capacitor C14, a sixth capacitor C15, a seventh capacitor C35, a twenty-third resistor R25, a twenty-fourth resistor R26, a twenty-fifth resistor R27, a twenty-sixth resistor R108, a twenty-seventh resistor R109, and a twenty-eighth resistor R110; the second connector J7 has two pins; Both pins of the second connector J7 are electrically connected to the liquid level sensor. The second pin of the second connector J7 is also electrically connected to the +12V power supply terminal through the first common-mode inductor D28, and the common pin of the first common-mode inductor D28 is grounded. The first pin of the second connector J7 is also electrically connected to the non-inverting input pin of the third operational amplifier U3B through the second common-mode inductor D29 and the twenty-third resistor R25, and the common pin of the second common-mode inductor D29 is grounded. The first terminal of the seventh capacitor C35 and the first terminal of the twenty-seventh resistor R109 are connected to the common connection terminal between the first pin of the second connector J7 and the second common-mode inductor D29, and the second terminals of the seventh capacitor C35 and the twenty-seventh resistor R109 are both grounded. The power supply pin of the third operational amplifier U3B is electrically connected to the 5V power supply terminal, and the first terminal of the fifth capacitor C14 is connected to the power supply terminal of the third operational amplifier U3B. The second end of the fifth capacitor C14 is grounded at the common connection between the source pin and the 5V power supply terminal; the ground pin of the third operational amplifier U3B is grounded; the first end of the twenty-sixth resistor R108 is connected to the common connection between the twenty-third resistor R25 and the non-inverting input pin of the third operational amplifier U3B, and the second end of the twenty-sixth resistor R108 is grounded; the inverting input pin of the third operational amplifier U3B is grounded through the twenty-fifth resistor R27, and the inverting input pin of the third operational amplifier U3B is also electrically connected to the output pin of the third operational amplifier U3B through the twenty-eighth resistor R110; the output pin of the third operational amplifier U3B is electrically connected to the input terminal of the main control board through the twenty-fourth resistor R26, the first end of the sixth capacitor C15 is connected to the common connection between the twenty-fourth resistor R26 and the input terminal of the main control board, and the second end of the sixth capacitor C15 is grounded.

[0018] Optionally, the digital liquid level detection circuit includes a liquid level switch, a fourth connector J8, a third optocoupler U17, a fourth optocoupler U8, an eighth capacitor C10, a ninth capacitor C40, a twenty-ninth resistor R39, a thirtieth resistor R40, a thirty-first resistor R41, a thirty-second resistor R70, a thirty-third resistor R71, and a thirty-fourth resistor R73; the fourth connector J8 has 5 pins; The first, second, and third pins of the fourth connector J8 are all electrically connected to the level switch, and the third pin of the fourth connector J8 is also grounded; the fourth pin of the fourth connector J8 is electrically connected to the negative input terminal of the fourth optocoupler U8 through the thirty-first resistor R41, and the fifth pin of the fourth connector J8 is electrically connected to the negative input terminal of the third optocoupler U17 through the thirty-fourth resistor R73; the first end of the thirty-third resistor R71 is electrically connected to the +12V power supply terminal, and the second end of the thirty-third resistor R71 and the first end of the ninth capacitor C40 are both connected to the common connection terminal between the fifth pin of the fourth connector J8 and the thirty-fourth resistor R73, and the second end of the ninth capacitor C40 is grounded; the thirtieth resistor R4... The first terminal of 0 is electrically connected to the +12V power supply terminal. The second terminal of the thirtieth resistor R40 and the first terminal of the eighth capacitor C10 are both connected to the common connection terminal between the fourth pin of the fourth connector J8 and the thirty-first resistor R41. The second terminal of the eighth capacitor C10 is grounded. The output collector of the third optocoupler U17 and the output collector of the fourth optocoupler U8 are both electrically connected to the input terminal of the main control board. The output collector of the third optocoupler U17 is also electrically connected to the circuit power supply terminal through the thirty-second resistor R70. The output collector of the fourth optocoupler U8 is also electrically connected to the circuit power supply terminal through the twenty-ninth resistor R39. The output emitter of the third optocoupler U17 and the output emitter of the fourth optocoupler U8 are both grounded.

[0019] Optionally, the fault indication unit includes a buzzer control circuit and an external alarm control circuit; The input terminals of the buzzer control circuit and the external alarm control circuit are both electrically connected to the output terminal of the main control board, and the output terminal of the external alarm control circuit is electrically connected to the external alarm device. The buzzer control circuit is used to receive a first alarm command issued by the main control board when the main control board determines that the sewage pump has a motor failure and / or a liquid level failure, and to issue a buzzer signal according to the first alarm command. The external alarm control circuit is used to receive a second alarm command issued by the main control board when the main control board determines that the sewage pump has a motor failure and / or a liquid level failure, and to issue an alarm signal through the external alarm device according to the second alarm command.

[0020] Optionally, the buzzer control circuit includes a first relay K1, a buzzer, a fifth connector J19, a second diode D14, a third diode D15, a fourth diode D16, a thirty-fifth resistor R68, and a thirty-sixth resistor R107; the fifth connector J19 has two pins. The positive terminal of the coil power supply of the first relay K1 is electrically connected to the circuit power supply terminal, and the negative terminal of the coil power supply of the first relay K1 is electrically connected to the output terminal of the main control board. The common terminal of the coil of the first relay K1 is grounded. The first normally open contact of the first relay K1 is left floating. The second normally open contact of the first relay K1 is electrically connected to the negative input terminal of the buzzer through the thirty-seventh resistor R107. The positive input terminal of the buzzer is electrically connected to the +12V power supply terminal through the second diode D14. The anode of the fourth diode D16 is connected to the common connection terminal between the thirty-seventh resistor R107 and the negative input terminal of the buzzer. The cathode of the fourth diode D16 and the third diode D16 are connected to the common connection terminal between the thirty-seventh resistor R107 and the negative input terminal of the buzzer. The negative terminal of diode D15 and the first end of the 35th resistor R68 are both connected to the common connection terminal between the positive input terminal of the buzzer and the second diode D14; the positive terminal of the third diode D15 and the second end of the 35th resistor R68 are both electrically connected to the 9V power supply terminal; the first pin of the fifth connector J19 is electrically connected to the positive terminal of the external battery box, and the first pin of the fifth connector J19 is also connected to the common connection terminal between the positive terminal of the third diode D15, the second end of the 35th resistor R68 and the 9V power supply terminal; the second pin of the fifth connector J19 is electrically connected to the negative terminal of the external battery box, and the second pin of the fifth connector J19 is also grounded.

[0021] Optionally, the external alarm control circuit includes a second relay K2 and a sixth connector J9; the sixth connector J9 has 3 pins; The positive terminal of the coil power supply of the second relay K2 is electrically connected to the +12V power supply terminal, the negative terminal of the coil power supply of the second relay K2 is electrically connected to the output terminal of the main control board, and the common terminal of the coil of the second relay K2 is electrically connected to the second pin of the first connector; the first normally open contact of the second relay K2 is electrically connected to the first pin of the sixth connector J9, and the second normally open contact of the second relay K2 is electrically connected to the third pin of the sixth connector J9; all three pins of the sixth connector J9 are also electrically connected to the external alarm device.

[0022] Optionally, the HMI control panel further includes a display module; The display module is communicatively connected to the main control board; The display module is used to receive display commands issued by the main control board when the main control board controls the sewage pump, so as to display and control the sewage pump.

[0023] Optionally, the system further includes a function expansion unit; The functional expansion unit is electrically connected to the main control board; The functional expansion unit is used to provide auxiliary functions to the sewage pump under the control of the main control board.

[0024] Optionally, the motor in the sewage pump is provided with a motor power supply circuit; the functional expansion unit includes a contactor control circuit; The input terminal of the contactor control circuit is electrically connected to the output terminal of the main control board, and the output terminal of the contactor control circuit is electrically connected to the motor power supply circuit. The contactor control circuit is used to receive a contactor control signal sent by the main control board when the main control board determines that the sewage pump has a motor failure, and to cut off the motor power supply circuit according to the contactor control signal; it is also used to obtain the contactor trigger action corresponding to the motor power supply circuit, and to cut off the motor power supply circuit according to the contactor trigger action.

[0025] Optionally, the contactor control circuit includes contactor T2, third relay K6, first contactor soldering hole JP7, second contactor soldering hole JP8, first transistor Q2, fifth diode D23, thirty-seventh resistor R78 and thirty-eighth resistor R81; The base of the first transistor Q2 is electrically connected to the output terminal of the main control board through the thirty-seventh resistor R78. The emitter of the first transistor Q2 is grounded. The first end of the thirty-eighth resistor R81 is connected to the common connection terminal between the base of the first transistor Q2 and the thirty-seventh resistor R78, and the second end of the thirty-eighth resistor R81 is grounded. The collector of the first transistor Q2 is electrically connected to the negative terminal of the coil power supply of the third relay K6. The positive terminal of the coil power supply of the third relay K6 is electrically connected to the +12V power supply terminal. The anode of the fifth diode D23 is connected to the common connection terminal between the collector of the first transistor Q2 and the negative terminal of the coil power supply of the third relay K6. The cathode of the fifth diode D23 is connected to the common connection terminal between the positive terminal of the coil power supply of the third relay K6 and the +12V power supply terminal. The stationary contact of the third relay K6 is electrically connected to the phase line of the motor power supply circuit through the contactor T2. The normally closed moving contact of the third relay K6 is electrically connected to the first end of the first contactor welding hole JP7. The second end of the first contactor welding hole JP7 is electrically connected to the first end of the second contactor welding hole JP8. The second end of the second contactor welding hole JP8 is grounded.

[0026] Optionally, the functional expansion unit further includes a serial communication interface circuit; The output terminal of the serial communication interface circuit is electrically connected to the input terminal of the main control board; The main control board is also used to communicate serially with external bus devices through the serial communication interface circuit, and to receive serial commands from the external bus devices to perform medium-distance control of the sewage pump.

[0027] Optionally, the functional expansion unit further includes a memory circuit and a clock circuit; Both the memory circuit and the clock circuit are electrically connected to the main control board.

[0028] In addition, the present invention also provides a method for intelligent control of a sewage pump, which uses the aforementioned intelligent control system for sewage pumps to control the sewage pumps; The method includes: The sewage pump can be manually controlled by receiving user commands through the button module in the HMI control panel using the main control board; or it can be remotely controlled by receiving remote commands from the remote terminal through the wireless communication module in the HMI control panel. When the main control board controls the sewage pump, the motor protection unit collects key electrical parameters of the motor configured in the sewage pump in real time and transmits the collected key electrical parameters to the main control board in real time; the dual-mode liquid level detection unit collects the first liquid level signal of the sewage pump in the main detection mode and transmits the first liquid level signal to the main control board; or collects the second liquid level signal of the sewage pump in the backup detection mode and transmits the second liquid level signal to the main control board; wherein the first liquid level signal and the second liquid level signal are different. Using the main control board, it is determined whether the sewage pump has a motor failure based on the key electrical parameters; and it is determined whether the sewage pump has a liquid level failure based on the first liquid level signal or the second liquid level signal. When the main control board determines that the sewage pump has a motor failure and / or a liquid level failure, it uses the fault indication module to issue a fault indication signal.

[0029] The beneficial effects of this invention are: During the control of the sewage pump, the button module on the HMI control panel, which is independent of the main control board, allows for manual control of the pump. This enables operators to adjust the pump's operating status on-site according to actual conditions. Furthermore, the wireless communication module on the HMI control panel allows for wireless communication with a remote terminal, receiving remote commands and enabling remote control of the sewage pump, thus improving the flexibility and convenience of pump control. Whether in manual or remote control mode, when the main control board controls the sewage pump, it can issue corresponding operating commands to the motor protection unit and the dual-mode liquid level detection unit. The motor protection unit can collect key electrical parameters of the motor in the sewage pump in real time and transmit them to the main control board, which can then make timely judgments based on these parameters. The system detects whether the motor has malfunctioned. Simultaneously, the dual-mode liquid level detection unit acquires the sewage pump's liquid level information (including a first or second liquid level signal). The main control board uses this information to determine if a liquid level fault has occurred. The dual-mode liquid level detection unit provides a primary detection mode and a backup detection mode, capable of collecting different types of liquid level signals. This dual-mode design increases the reliability of liquid level detection; even if the primary detection mode malfunctions, the backup detection mode can continue to operate, ensuring the main control board can accurately acquire the sewage pump's liquid level information to determine if a liquid level fault has occurred. When the main control board determines that the sewage pump has experienced a motor fault and / or a liquid level fault, the fault indication module will issue a fault indication signal to promptly remind relevant personnel to handle the situation, preventing the fault from escalating and reducing equipment damage and maintenance costs. The intelligent control system and control method for sewage pumps of the present invention realize comprehensive intelligent and automated control of sewage pumps, effectively improving the stability and reliability of sewage pump operation; the entire control system is compact in design, cost-controllable, fully functional and supports remote monitoring in multiple ways, can better adapt to various complex sewage discharge environments, improve sewage discharge efficiency, ensure the smooth progress of sewage treatment work, and provide strong support for the efficient operation and sustainable development of the sewage treatment industry. Attached Figure Description

[0030] The features and advantages of the invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the invention in any way. In the drawings: Figure 1 A structural diagram of a sewage pump intelligent control system according to Embodiment 1 of the present invention is shown; Figure 2 A structural diagram of another intelligent control system for sewage pumps according to Embodiment 1 of the present invention is shown; Figure 3A The chip structure diagram of the WIFI communication module in Embodiment 1 of the present invention is shown; Figure 3BThis shows a design diagram of connector P2 on the HMI control panel in Embodiment 1 of the present invention; Figure 3C This shows a design diagram of connector P1 on the HMI control panel in Embodiment 1 of the present invention; Figure 3D The diagram shows a design of the button module in Embodiment 1 of the present invention; Figure 4 The design diagram of the phase current detection circuit in Embodiment 1 of the present invention is shown; Figure 5 The diagram shows the design of the phase voltage detection circuit in Embodiment 1 of the present invention; Figure 6 The diagram shows the design of the motor overheat detection circuit in Embodiment 1 of the present invention; Figure 7 The diagram shows the design of the zero-crossing detection circuit in Embodiment 1 of the present invention; Figure 8 The diagram shows the design of the analog liquid level detection circuit in Embodiment 1 of the present invention; Figure 9 The diagram shows the design of the digital liquid level detection circuit in Embodiment 1 of the present invention; Figure 10 The diagram shows the design of the buzzer control circuit in Embodiment 1 of the present invention; Figure 11 The diagram shows the design of the external alarm control circuit in Embodiment 1 of the present invention; Figure 12 The diagram shows the design of the contactor control circuit in Embodiment 1 of the present invention; Figure 13 The design diagram of the serial communication interface circuit in Embodiment 1 of the present invention is shown; Figure 14 The diagram shows the design of the clock circuit in Embodiment 1 of the present invention; Figure 15 The diagram shows the design of the memory circuit in Embodiment 1 of the present invention; Figure 16 A flowchart of a sewage pump intelligent control method according to Embodiment 2 of the present invention is shown. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] In this embodiment of the invention, the term "and / or" describes the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following associated objects have an "or" relationship.

[0033] It should be noted that the terms "first," "second," etc., in the specification, claims, and drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0034] In this embodiment of the invention, the term "multiple" refers to two or more, and other quantifiers are similar.

[0035] Example 1 A smart control system for sewage pumps, such as Figure 1 As shown, the system includes a main control board, an HMI control panel, a motor protection unit, a dual-mode liquid level detection unit, and a fault indication unit. The HMI control panel includes a wireless communication module and a button module that are independent of the main control board; wherein, the wireless communication module is communicatively connected to the main control board, and the button module is electrically connected to the main control board; the motor protection unit, the dual-mode liquid level detection unit, and the fault indication unit are all electrically connected to the main control board; The main control board is used to receive user commands through the button module in the HMI control panel to manually control the sewage pump; it is also used to communicate wirelessly with a remote terminal through the wireless communication module to receive remote commands from the remote terminal to remotely control the sewage pump. The motor protection unit is used to collect key electrical parameters of the motor configured in the sewage pump in real time when the main control board controls the sewage pump, and transmit the collected key electrical parameters to the main control board in real time. The dual-mode liquid level detection unit has a main detection mode and a backup detection mode. When the main control board controls the sewage pump, it acquires a first liquid level signal from the sewage pump according to the main detection mode and transmits the first liquid level signal to the main control board. It is also used when the main control board controls the sewage pump, it acquires a second liquid level signal from the sewage pump according to the backup detection mode and transmits the second liquid level signal to the main control board. The first liquid level signal and the second liquid level signal are different. The main control board is also used to receive the key electrical parameters transmitted by the motor protection unit, and determine whether the sewage pump has a motor failure based on the key electrical parameters; it is also used to receive the first liquid level signal or the second liquid level signal transmitted by the dual-mode liquid level detection unit, and determine whether the sewage pump has a liquid level failure based on the first liquid level signal or the second liquid level signal. The fault indication module is used to issue a fault indication signal when the main control board determines that the sewage pump has a motor fault and / or a liquid level fault.

[0036] In this embodiment, during the control of the sewage pump, the button module on the HMI control panel, which is independent of the main control board, allows for manual control of the sewage pump. This facilitates operators in adjusting the pump's operating status on-site according to actual conditions. Furthermore, the wireless communication module on the HMI control panel enables wireless communication with a remote terminal, allowing the receipt of remote commands and remote control of the sewage pump, thus improving the flexibility and convenience of pump control. Whether in manual or remote control mode, when the main control board controls the sewage pump, it can issue corresponding operating commands to the motor protection unit and the dual-mode liquid level detection unit. The motor protection unit can collect key electrical parameters of the motor in the sewage pump in real time and transmit them to the main control board. The main control board can then adjust the pump's operation based on these parameters. The system can simultaneously determine whether the motor has malfunctioned. At the same time, the dual-mode liquid level detection unit can acquire the liquid level information of the sewage pump (including a first liquid level signal or a second liquid level signal). The main control board uses this liquid level information to determine whether a liquid level fault has occurred. The dual-mode liquid level detection unit provides a main detection mode and a backup detection mode, capable of collecting different forms of liquid level signals. This dual-mode design increases the reliability of liquid level detection; even if the main detection mode malfunctions, the backup detection mode can continue to operate, ensuring that the main control board can accurately acquire the liquid level information of the sewage pump, thereby determining whether a liquid level fault has occurred. When the main control board determines that the sewage pump has experienced a motor fault and / or a liquid level fault, the fault indication module will issue a fault indication signal to promptly remind relevant personnel to handle the situation, preventing the fault from escalating and reducing equipment damage and maintenance costs.

[0037] The intelligent control system for sewage pumps in this embodiment realizes comprehensive intelligent and automated control of sewage pumps, effectively improving the stability and reliability of sewage pump operation. The entire control system is compact in design, cost-controllable, and fully functional, and supports remote monitoring in multiple ways. It can better adapt to various complex sewage discharge environments, improve sewage discharge efficiency, ensure the smooth progress of sewage treatment work, and provide strong support for the efficient operation and sustainable development of the sewage treatment industry.

[0038] The following is a further description of each unit of the intelligent sewage pump control system in this embodiment.

[0039] In this embodiment, the main control board can be a circuit board integrating key components such as a microprocessor, memory, and input / output interfaces. The microprocessor, as the core of the main control board, possesses powerful computing and processing capabilities, enabling rapid analysis and processing of data from the HMI control panel, motor protection unit, and dual-mode liquid level detection unit. The memory stores the programs and data required for system operation, ensuring stable system operation. The input / output interfaces enable effective data interaction with various units, achieving precise control of the sewage pump.

[0040] The main control board receives user commands from the button module on the HMI control panel, converts these commands into specific control signals, and directly adjusts the operating status of the sewage pump. This includes basic functions such as starting, stopping, and adjusting the speed, as well as more advanced settings such as motor protection start / stop and switching the working mode of the dual-mode liquid level detection unit. Through collaboration with the wireless communication module of the HMI control panel, the main control board can receive commands from remote terminals, enabling remote control. Upon receiving a remote command, the main control board quickly parses the command and performs corresponding operations on the sewage pump based on the command content, ensuring the real-time performance and accuracy of remote control. The commands for remote control are similar to those for manual control and will not be listed here.

[0041] The HMI control panel includes a variety of function buttons to meet the diverse control needs of operators. For example, there is a start button; pressing this button sends a start signal to the main control board, which then controls the sewage pump to begin operating and transport sewage to the designated location. There is also a stop button; pressing this button immediately sends a stop command to the main control board, stopping the sewage pump and preventing unnecessary energy consumption and equipment wear. Finally, there are speed adjustment buttons; operators can adjust the speed of the sewage pump motor according to the actual sewage flow rate and discharge requirements, achieving precise control over the sewage discharge rate.

[0042] In addition, the button module also includes function buttons related to motor protection. For example, there's a motor protection start button; pressing this button activates the motor protection unit to collect key electrical parameters of the sewage pump motor in real time, providing data support for the main control board to determine if a motor fault has occurred. The motor protection stop button pauses the motor protection unit's operation. Furthermore, a working mode switching button is provided for the dual-mode liquid level detection unit. Operators can switch between the main detection mode and the backup detection mode by pressing this button, ensuring accurate acquisition of sewage pump liquid level information, based on the actual situation on site.

[0043] Preferably, such as Figure 2 As shown, the HMI control panel also includes a display module; The display module is communicatively connected to the main control board; The display module is used to receive display commands issued by the main control board when the main control board controls the sewage pump, so as to display and control the sewage pump.

[0044] The display module on the control panel provides a clear view of the sewage pump's operating status. It shows various parameters in real time, such as key electrical parameters like motor current, voltage, and power, as well as the sewage level. By observing the display, operators can quickly understand the pump's operation and determine if it is functioning correctly. If abnormal fluctuations occur in the motor's current or voltage, operators can react promptly based on the displayed information, taking appropriate measures such as checking for motor malfunctions or adjusting the pump's operating parameters.

[0045] The display module can also display fault information. When the main control board determines that the sewage pump has a motor fault and / or a liquid level fault, it will send a fault display command to the display module. The display module will then display the fault information in a prominent manner, such as flashing warning lights or red fault codes. In this way, operators do not need to wait for the fault indication module to issue a prompt signal; they can discover the fault immediately by checking the display module, further improving the timeliness of fault handling.

[0046] In addition, the display module can store and display historical operating data of the sewage pump. Operators can use the button module to view the changes in the operating parameters of the sewage pump at different time periods, and analyze the operating patterns and performance trends of the sewage pump. This helps operators to identify potential problems in advance, carry out preventive maintenance, and extend the service life of the sewage pump. At the same time, historical operating data can also provide data support for optimizing sewage treatment operations, such as rationally adjusting the operating strategy of the sewage pump according to the sewage flow and discharge requirements at different time periods, thereby improving sewage treatment efficiency.

[0047] Corresponding to the aforementioned display module, the button module may also be equipped with a status display button, which facilitates the operation and monitoring of the system by the operator. Pressing this status display button will display the current operating status of the sewage pump, key electrical parameters of the motor, liquid level information, etc., allowing the operator to understand the working status of the sewage pump in a timely manner so as to make reasonable decisions.

[0048] Of course, the button module mentioned above can be a physical button or a touch button integrated into the display module. The specific form can be selected according to the actual design requirements and usage scenarios.

[0049] In the HIM control panel, the wireless communication module is specifically a Wi-Fi communication module. This module features high transmission speed and wide coverage, ensuring that remote commands are transmitted quickly and accurately to the main control board, while also providing timely feedback of sewage pump operating data to the remote terminal. The Wi-Fi module enables stable data interaction with the main control board, achieving efficient wireless communication with the remote terminal. Through this module, operators can remotely monitor and control the sewage pump from anywhere with network coverage, greatly improving operational convenience and flexibility.

[0050] Specifically, in this embodiment, the HMI control panel is equipped with connector P2, and the chip structure of the WIFI communication module is as follows: Figure 3A As shown, the design diagram of connector P2 is as follows: Figure 3B As shown, the WIFI communication module communicates with the main control board via a wiring harness and connector P2. The specific signal transmission and reception path is as follows: UART1_TX pin of the main control chip → wiring harness → WIFI_RXD pin of connector P2 on the HMI control panel → internal PCB trace of the HMI control panel → WIFI_RXD pin of WIFI communication module U2. Conversely, the path is: WIFI_TXD pin of WIFI communication module U2 → internal PCB trace of the HMI control panel → WIFI_TXD pin of P2 on the HMI control panel → wiring harness → UART1_RX pin of the main control board.

[0051] In addition, the main control board is also connected to the display module (specifically the LCD module) via a wiring harness and connector P2, such as... Figure 3B As shown, the signal path is as follows: UART2_TX pin of the main control chip → wiring harness → LCD_RX pin of P2 connector on the HMI control panel → internal PCB trace of the HMI control panel → RX pin of the LCD module. Conversely, the path is: TX pin of the LCD module → internal PCB trace of the HMI control panel → LCD_TX pin of P2 on the HMI control panel → wiring harness → UART2_RX pin of the main control board.

[0052] Furthermore, the HMI control panel also includes connector P1, the design diagram of which is shown below. Figure 3C As shown, the design diagram of the button module is as follows: Figure 3D As shown, the button module is electrically connected to the main control board via connector P1. Figure 3D In the middle, the button module contains 5 buttons K1~K5. One end of each of these 5 buttons is grounded, and the other end is connected to the Key1_IN~Key4_IN pins of connector P1 on the HMI control panel. These 5 pins are also connected to the five signal input pins (e.g., PA0~PA4 pins) of the main control board through a wiring harness.

[0053] Preferably, the motor in the sewage pump is provided with a motor power supply circuit, and the key electrical parameters include the motor phase current signal and the motor phase voltage signal in the motor power supply circuit; like Figure 2 As shown, the motor protection unit includes a phase current detection circuit and a phase voltage detection circuit. The input terminals of the phase current detection circuit and the phase voltage detection circuit are both electrically connected to the motor power supply circuit, and the output terminals of the phase current detection circuit and the phase voltage detection circuit are both electrically connected to the input terminal of the main control board. The phase current detection circuit is used to collect the motor phase current signal in the motor power supply circuit and transmit the motor phase current signal to the main control board; The phase voltage detection circuit is used to collect the motor phase voltage signal in the motor power supply circuit and transmit the motor phase voltage signal to the main control board.

[0054] The phase current detection circuit and phase voltage detection circuit play a crucial role in the entire motor protection unit. The phase current detection circuit accurately captures the phase current signal in the motor power supply circuit. When the motor is running normally, the phase current has a relatively stable value range. However, once a fault such as motor overload or short circuit occurs, the phase current will change significantly. The phase current detection circuit will promptly capture these changing signals and quickly transmit them to the main control board. After receiving the phase current signal, the main control board will compare and analyze it with the preset normal current threshold. If the phase current is detected to exceed the normal range, the main control board will determine that the motor may have a current abnormality fault and take corresponding protective measures, such as issuing an alarm signal or stopping the sewage pump, to prevent the motor from being damaged by excessive current.

[0055] The phase voltage detection circuit focuses on acquiring the phase voltage signal of the motor in the motor power supply circuit. During motor operation, abnormal phase voltage may be caused by various reasons such as power supply failure and line fault. The phase voltage detection circuit monitors the changes in phase voltage in real time and transmits the acquired phase voltage signal to the main control board in a timely manner. The main control board performs in-depth analysis of the phase voltage signal and compares it with the preset normal voltage range. If the phase voltage deviates from the normal range, whether it is too high or too low, it means that there may be a problem with the motor operating environment. At this time, the main control board will react according to the actual situation to ensure that the motor does not operate under abnormal voltage for a long time and reduce the risk of motor damage caused by abnormal voltage.

[0056] In this embodiment, through the coordinated operation of the phase current detection circuit and the phase voltage detection circuit, the motor protection unit can monitor the motor's operating status comprehensively and in real time, providing a strong guarantee for the stable operation of the sewage pump. At the same time, this dual detection mechanism also improves the accuracy and reliability of motor fault detection, further enhancing the performance of the entire intelligent control system for the sewage pump.

[0057] It should be understood that since the motor power supply may be single-phase or three-phase, for three-phase power supplies, both the phase current detection circuit and the phase voltage detection circuit need to detect the current and voltage of the three phases. This can be achieved by setting up three phase current detection circuits and three phase voltage detection circuits, each corresponding to one of the three phases of the motor. Each detection circuit can accurately collect the current and voltage signals of that phase. Through corresponding settings, the operating status of each phase of the motor can be comprehensively and meticulously monitored.

[0058] Specifically, such as Figure 4 As shown, the phase current detection circuit includes a current transformer U11, a first operational amplifier U12A, a first diode bridge rectifier, a first electrolytic capacitor C30, a first capacitor C7, a first resistor R5, a second resistor R6, a third resistor R7, a fourth resistor R37, a fifth resistor R38, and a sixth resistor R103. The primary side of current transformer U11 is electrically connected to one phase line of the motor power supply circuit, and the secondary side of current transformer U11 is electrically connected to the input terminal of the first diode bridge rectifier. The negative terminal of the output terminal of the first diode bridge rectifier is grounded. The positive terminal of the output terminal of the first diode bridge rectifier is electrically connected to the non-inverting input pin of the first operational amplifier U12A through the first resistor R5. The positive terminal of the first electrolytic capacitor C30 and the first terminal of the sixth resistor R103 are both connected to the common connection terminal between the positive terminal of the output terminal of the first diode bridge rectifier and the first resistor R5. The negative terminal of the first electrolytic capacitor C30 and the second terminal of the sixth resistor R103 are both grounded. The first terminal of the fourth resistor R37 is connected to the first... A resistor R5 is connected to the common connection between the non-inverting input pin of the first operational amplifier U12A, and the second end of the fourth resistor R37 is grounded; the power supply pin of the first operational amplifier U12A is electrically connected to the circuit power supply terminal, and the sibling pins of the first operational amplifier U12A are grounded; the inverting input pin of the first operational amplifier U12A is grounded through the third resistor R7, and is also electrically connected to the output pin of the first operational amplifier U12A through the fifth resistor R38; the output pin of the first operational amplifier U12A is electrically connected to the input terminal of the main control board through the second resistor R6; the first end of the first capacitor C7 is connected to the common connection between the second resistor R6 and the input terminal of the main control board, and the second end of the first capacitor C7 is grounded.

[0059] In the phase current detection circuit of the above structural design, the primary side of the current transformer U11 is electrically connected to one phase line of the motor power supply circuit, which can convert the motor phase current into a small current signal on the secondary side according to a certain ratio. This small current signal on the secondary side is input to the first diode bridge rectifier (i.e., Figure 4 In the rectifier unit composed of D6~D9, alternating current is converted into direct current. During this process, the first electrolytic capacitor C30 acts as a filter, making the rectified DC signal smoother and more stable.

[0060] The first operational amplifier, U12A, forms an amplification circuit that amplifies the rectified and filtered signal, enabling the main control board to detect and analyze it more accurately. The non-inverting and inverting input pins of the first operational amplifier U12A are connected to corresponding resistors; by properly configuring these resistors, the amplification factor can be adjusted. The first capacitor, C7, acts as a filter capacitor, further filtering the amplified signal to remove any potential high-frequency interference, ensuring that the signal transmitted to the main control board is pure and stable.

[0061] When the motor phase current changes, the current on the secondary side of current transformer U11 also changes accordingly. After rectification, filtering, and amplification, the signal ultimately transmitted to the main control board also changes. Based on the received signal changes, the main control board can understand the magnitude and status of the motor phase current in real time.

[0062] Specifically, such as Figure 5 As shown, the phase voltage detection circuit includes a transformer U13, a second operational amplifier U14A, a second diode bridge rectifier, a second electrolytic capacitor C31, a second capacitor C5, a third capacitor C6, a seventh resistor R1, an eighth resistor R2, a ninth resistor R3, a tenth resistor R4, an eleventh resistor R34, a twelfth resistor R36, and a thirteenth resistor R99. The first terminal of the primary side of transformer U13 is electrically connected to one phase line of the motor power supply circuit through the thirteenth resistor R33, and the second terminal of the primary side of transformer U13 is electrically connected to the reference point of the motor power supply circuit; the secondary side of transformer U13 is electrically connected to the input terminal of the second diode bridge rectifier; the negative terminal of the output terminal of the second diode bridge rectifier is grounded; the positive terminal of the output terminal of the second diode bridge rectifier is electrically connected to the non-inverting input pin of the second operational amplifier U14A through the seventh resistor R1; the positive terminal of the second electrolytic capacitor C31 and the first terminal of the eighth resistor R2 are both connected to the common connection terminal between the positive terminal of the output terminal of the second diode bridge rectifier and the seventh resistor R1; the negative terminal of the second electrolytic capacitor C31 and the second terminal of the eighth resistor R2 are both grounded; the first terminal of the eleventh resistor R34 is connected to the seventh resistor R1. The second end of the eleventh resistor R34 is grounded on the common connection terminal between the non-inverting input pin of the second operational amplifier U14A and the common connection terminal between the non-inverting input pin of the second operational amplifier U14A and the 5V power supply terminal. The ground pin of the second operational amplifier U14A is grounded. The inverting input pin of the second operational amplifier U14A is grounded through the tenth resistor R4 and is also electrically connected to the output pin of the second operational amplifier U14A through the twelfth resistor R36. The output pin of the second operational amplifier U14A is electrically connected to the input terminal of the main control board through the ninth resistor R3. The first end of the second capacitor C5 is connected to the common connection terminal between the ninth resistor R3 and the input terminal of the main control board, and the second end of the second capacitor C5 is grounded.

[0063] Similar to the phase current detection circuit, in the phase voltage detection circuit designed above, the primary side of transformer U13 is electrically connected to one phase line of the motor power supply circuit and a reference point. This allows the motor phase voltage to be converted into a small voltage signal on the secondary side at a certain ratio. This small voltage signal is then input to the second diode bridge rectifier, where the AC voltage is converted into DC voltage. Similarly, the second electrolytic capacitor C31 acts as a filter, making the rectified DC signal more stable and smooth. The second operational amplifier U14A forms an amplification circuit, amplifying the rectified and filtered signal for accurate detection and analysis by the main control board. The amplification factor can be adjusted by properly configuring the resistors connected to the non-inverting and inverting input pins of the second operational amplifier U14A. The second capacitor C5 acts as a filter capacitor, further filtering the amplified signal to eliminate potential high-frequency interference and ensure the purity and stability of the signal transmitted to the main control board.

[0064] When the motor phase voltage changes, the voltage on the secondary side of transformer U13 also changes accordingly. After a series of processes such as rectification, filtering, and amplification, the signal ultimately transmitted to the main control board will also change. Based on the received signal changes, the main control board can monitor the magnitude and status of the motor phase voltage in real time.

[0065] Preferably, the key electrical parameters further include a temperature detection signal for characterizing the motor temperature; like Figure 2 As shown, the motor protection unit also includes a motor overheat detection circuit, the output of which is electrically connected to the input of the main control board. The motor overheat detection circuit is used to collect temperature detection signals from the motor and transmit the temperature detection signals to the main control board.

[0066] During prolonged operation, motor temperatures can rise due to resistance heat generated by current flowing through the windings and heat generated by mechanical friction. If the motor temperature becomes excessively high and is not controlled in time, it will accelerate the aging of the motor's insulation materials, reduce the motor's lifespan, and may even lead to serious malfunctions such as motor burnout. This embodiment incorporates a motor overheat detection circuit to monitor the motor's temperature in real time. When the motor temperature is within the normal range, the temperature detection signal collected by the overheat detection circuit is at a relatively stable value and is transmitted to the main control board. Upon receiving the signal, the main control board determines that the motor temperature is normal, and the sewage pump can continue to operate normally. However, if the motor temperature rises abnormally due to overload, poor heat dissipation, or other reasons, the motor overheat detection circuit will quickly detect the change in the temperature detection signal and promptly transmit the changed signal to the main control board. Upon receiving the abnormal temperature detection signal, the main control board immediately compares it with a pre-set temperature threshold. If the detected motor temperature exceeds the normal range, the main control board will react quickly and take a series of protective measures. For example, the main control board may issue an alarm signal to remind the operator to pay attention to abnormal motor temperature; at the same time, the main control board may also control the sewage pump to reduce the operating power, reduce the heat generated by the motor, or directly stop the operation of the sewage pump to avoid damage to the motor due to overheating.

[0067] Through the coordinated operation of the motor overheat detection circuit, phase current detection circuit, and phase voltage detection circuit, the intelligent control system for the sewage pump can comprehensively and in real-time monitor the motor's operating status, promptly detect and address various potential faults, and provide a solid guarantee for the stable and safe operation of the sewage pump. This multi-dimensional detection and protection mechanism greatly improves the reliability and stability of the entire intelligent control system for the sewage pump, reduces equipment downtime and maintenance costs caused by motor failures, and has significant economic and social benefits.

[0068] Specifically, such as Figure 6As shown, the motor overheat detection circuit includes a temperature sensor (not shown), a first connector J12, a first optocoupler U15, a fourth capacitor C38, a fourteenth resistor R28, a fifteenth resistor R65, a sixteenth resistor R66, and a seventeenth resistor R67; the first connector J12 has two pins; the temperature sensor is located on the motor. The first and second pins of the first connector J12 are both electrically connected to the output terminal of the temperature sensor. The first pin of the first connector J12 is also electrically connected to the +12V power supply terminal through the fifteenth resistor R65. The second pin of the first connector J12 is also electrically connected to the positive input terminal of the first optocoupler U15. The first end of the fourth capacitor C38 and the first end of the sixteenth resistor R66 are both connected to the common connection terminal between the second pin of the first connector J12 and the positive input terminal of the first optocoupler U15. The second end of the fourth capacitor C38 and the second end of the sixteenth resistor R66 are both grounded. The negative input terminal of the first optocoupler U15 is grounded. The collector of the output side of the first optocoupler U15 is electrically connected to the +3.3V power supply terminal. The collector-emitter of the output side of the first optocoupler U15 is electrically connected to the input terminal of the main control board through the fourteenth resistor R28. The first end of the seventeenth resistor R67 is connected to the common connection terminal between the collector-emitter of the output side of the first optocoupler U15 and the fourteenth resistor R28. The second end of the seventeenth resistor R67 is grounded.

[0069] In the motor overheat detection circuit designed above, a temperature sensor installed on the motor can accurately sense the actual temperature of the motor and convert the temperature information into an electrical signal output. The first connector J12 serves as a bridge connecting the temperature sensor and subsequent circuits, ensuring smooth transmission of the temperature signal. When the motor temperature is normal, the electrical signal output by the temperature sensor is within a stable range, and a stable current flows through the input side of the first optocoupler U15, resulting in a stable conduction state between the collector and emitter on its output side. At this time, the signal transmitted to the main control board input after voltage division by the fourteenth resistor R28 is also within the normal range. The main control board determines that the motor temperature is normal, and the sewage pump continues to operate stably. However, once the motor temperature rises abnormally, the electrical signal output by the temperature sensor will change significantly. This change will cause a change in the current on the input side of the first optocoupler U15, thus affecting the conduction state on its output side. This change will cause a corresponding change in the signal transmitted to the main control board input. Through this change detection, motor overheat detection and protection can be achieved, providing reliable temperature protection for the stable operation of the sewage pump. This circuit design is simple, reliable, and low-cost, making it highly practical.

[0070] In the aforementioned motor overheat detection circuit, the fourth capacitor C38 acts as a filter, removing high-frequency interference from the temperature sensor's output signal and ensuring a pure and stable signal transmitted to the first optocoupler U15. The sixteenth resistor R66 limits current to prevent excessive current from damaging the input side of the first optocoupler U15. The seventeenth resistor R67 acts as a pull-down resistor, ensuring that the input level of the main control board remains stable at a low level when the collector-emitter junction of the first optocoupler U15 is not conducting, thus avoiding misjudgments.

[0071] Preferably, the key electrical parameters also include the digital pulse signal generated when the power supply voltage in the motor power supply circuit crosses zero; like Figure 2 As shown, the motor protection unit also includes two identical zero-crossing detection circuits. The input terminals of the two zero-crossing detection circuits are electrically connected to different phase lines of the motor power supply circuit, and the output terminals of the two zero-crossing detection circuits are electrically connected to the input terminal of the main control board. Each zero-crossing detection circuit is used to detect the digital pulse signal generated when the phase voltage in the corresponding phase line crosses zero, and transmits the digital pulse signal to the main control board. The main control board is used to compare the phase difference between the two received digital pulse signals and identify whether the motor power supply circuit is a single-phase power supply or a three-phase power supply based on the phase difference.

[0072] In actual sewage pump operation scenarios, the motor power supply circuit may use single-phase or three-phase power supply. Different power supply types have a significant impact on the motor's operating characteristics and performance. This embodiment sets up two zero-crossing detection circuits with the same structure, which can accurately identify the power supply type of the motor power supply circuit.

[0073] When the motor power supply circuit is a three-phase power supply, there is a 120° phase difference between the three phase voltages. Two zero-crossing detection circuits detect the zero-crossing points of the phase voltages of different phase lines, generating digital pulse signals with specific phase differences. After receiving these two digital pulse signals, the main control board can accurately determine whether a three-phase power supply is currently being used by comparing their phase differences. For example, when the phase difference between the two digital pulse signals is close to 120°, the main control board can determine that the motor power supply circuit is a three-phase power supply. When the motor power supply circuit is a single-phase power supply, the phase difference between the digital pulse signals detected by the two zero-crossing detection circuits is significantly different from that in the case of a three-phase power supply, and the main control board can identify that the current power supply is a single-phase power supply based on this difference.

[0074] Different power supply types differ in power output and stability, requiring system parameter adjustments and control strategy optimization based on the power supply type. For example, under three-phase power, the sewage pump can achieve higher power output and more stable operation; while under single-phase power, the system may need to adjust the motor's operating parameters to ensure the sewage pump can still operate normally under limited power conditions. Therefore, accurately identifying the power supply type is crucial for the efficient operation of the sewage pump intelligent control system. After identifying the power supply type, the main control board will precisely control the sewage pump according to the corresponding control logic.

[0075] In the intelligent control system of sewage pumps, the zero-crossing detection circuit works in conjunction with the phase current detection circuit, phase voltage detection circuit, and motor overheat detection circuit to form a comprehensive and multi-level monitoring and protection system. This system ensures the stable and safe operation of the sewage pump under different power supply conditions, improves the intelligence level and operating efficiency of the entire system, and provides strong support for sewage treatment.

[0076] Specifically, such as Figure 7 As shown, each of the zero-crossing detection circuits includes a second optocoupler, a first diode, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, and a twenty-second resistor. In each of the zero-crossing detection circuits, the first end of the nineteenth resistor and the first end of the twenty-first resistor are both coupled to the phase line corresponding to the motor power supply circuit. The second end of the nineteenth resistor is connected to the positive input terminal of the second optocoupler through the twentieth resistor and the first diode in sequence. The second end of the twenty-first resistor is connected to the negative input terminal of the second optocoupler through the twenty-second resistor. The collector of the output side of the second optocoupler is connected to the input terminal of the main control board. The collector of the output side of the second optocoupler is also connected to the +3.3V power supply terminal through the eighteenth resistor. The emitter of the output side of the second optocoupler is grounded.

[0077] exist Figure 7 In the diagram, optocoupler PC2 is the second optocoupler, diode D22 is the first diode, and resistors R31, R85, R86, R88, and R89 are the eighteenth to twenty-second resistors, respectively.

[0078] In the zero-crossing detection circuit designed above, the nineteenth resistor R85 and the twenty-first resistor R88 act as a voltage divider, dividing the high voltage in the corresponding phase line of the motor power supply circuit to ensure that the voltage input to subsequent circuits is within a safe and appropriate range, preventing excessive voltage from damaging components such as the second optocoupler PC2. The twentieth resistor R86 further limits the current, preventing excessive current from flowing through the input side of the first diode D22 and the second optocoupler PC2, protecting them from damage. The first diode D22 acts as a unidirectional conductor, allowing only positive current to flow, rectifying the AC signal so that the input side of the second optocoupler PC2 only receives a positive voltage signal. When the phase voltage of the corresponding phase line in the motor power supply circuit crosses zero, the current on the input side of the second optocoupler PC2 changes, thus affecting the conduction state of its output side. The collector of the output side of the second optocoupler PC2 is electrically connected to the input terminal of the main control board. The change in its conduction state causes a corresponding change in the level signal transmitted to the input terminal of the main control board, thereby generating a digital pulse signal. The eighteenth resistor, R31, acts as a pull-up resistor, ensuring that the input level of the main control board remains stable at a high level when the collector of the second optocoupler PC2 is on, thus guaranteeing accurate signal transmission. When the collector of the second optocoupler PC2 is not on, the pull-up resistor also helps maintain a stable input level of the main control board, preventing misjudgments.

[0079] This zero-crossing detection circuit is simple and reliable, accurately detecting the digital pulse signal generated when the phase voltage in the motor power supply circuit crosses zero. By using two zero-crossing detection circuits to detect different phase lines and transmitting the detected digital pulse signals to the main control board, the main control board can accurately identify whether the motor power supply circuit is single-phase or three-phase, thus providing crucial foundational data for the efficient operation of the sewage pump intelligent control system. Figure 7 One zero-crossing detection circuit is shown here. The other zero-crossing detection circuit has the same structure and will not be shown here.

[0080] Preferably, the first liquid level signal is an analog liquid level signal, and the second liquid level signal is a digital liquid level signal. like Figure 2 As shown, the dual-mode liquid level detection unit includes an analog liquid level detection circuit and a digital liquid level detection circuit, both of which are electrically connected to the input terminal of the main control board. The analog liquid level detection circuit is used to collect the analog liquid level signal of the sewage pump, and convert the analog liquid level signal into a liquid level voltage signal and transmit it to the main control board. The digital liquid level detection circuit is used to collect the digital liquid level signal of the sewage pump and transmit the digital liquid level signal to the main control board.

[0081] Analog liquid level detection circuits provide continuous and accurate liquid level information. Their working principle is based on the fact that changes in liquid level cause changes in certain physical quantities, such as pressure and capacitance. These changes are converted into electrical signals by appropriate sensors, thus obtaining an analog liquid level signal. In practical applications, analog liquid level detection circuits can use pressure sensors. When the liquid level rises, the pressure of the liquid on the sensor increases, and the electrical signal output by the sensor changes accordingly. The circuit processes the acquired analog liquid level signal, converting it into a liquid level voltage signal corresponding to the liquid level, and then transmits it to the main control board. After receiving the liquid level voltage signal, the main control board can accurately calculate the current liquid level height according to a preset algorithm.

[0082] The digital liquid level detection circuit is mainly used to provide switch information about the liquid level, i.e., whether the liquid level has reached a certain set threshold. It typically uses sensors such as float switches or photoelectric switches. When the liquid level reaches the set threshold, the sensor outputs a digital signal, such as a high or low level. The digital liquid level detection circuit directly transmits the collected digital liquid level signal to the main control board. Based on the received digital liquid level signal, the main control board can determine whether the liquid level has met the preset conditions for starting or stopping the sewage pump.

[0083] In the dual-mode liquid level detection unit described above, the analog liquid level detection circuit serves as the primary detection circuit, while the digital liquid level detection circuit acts as a backup detection circuit, enabling dual-protection detection of the sewage pump's liquid level. When the analog liquid level detection circuit operates normally, it provides high-precision liquid level data to the main control board. The main control board can then use this precise data to finely control the sewage pump, allowing for accurate adjustments to the pump's start and stop times based on the actual liquid level, preventing sewage overflow or pump dry running. Conversely, if the analog liquid level detection circuit malfunctions, such as sensor damage or signal transmission line interruption, the digital liquid level detection circuit immediately takes over. Through simple switching signals, this circuit can promptly inform the main control board whether the liquid level has reached the preset critical threshold, ensuring the sewage pump continues to operate safely under basic liquid level control requirements.

[0084] This embodiment, through the design of this dual-mode liquid level detection unit, can significantly improve the reliability and stability of the sewage pump intelligent control system in terms of liquid level detection. In scenarios with high requirements for sewage treatment, such as large sewage treatment plants and sewage discharge treatment in chemical enterprises, even if the analog liquid level detection circuit experiences a temporary failure, the system will not immediately fall into a state of out of control. The digital liquid level detection circuit can maintain the basic operation of the system to a certain extent, giving maintenance personnel time to troubleshoot and repair the fault. Through the cooperation of this unit with the motor overheat detection circuit, phase current detection circuit, phase voltage detection circuit, and zero-crossing detection circuit, a more complete and intelligent sewage pump intelligent control system is further constructed.

[0085] Specifically, such as Figure 8 As shown, the analog liquid level detection circuit includes a liquid level sensor (not shown in the figure), a second connector J7, a first common-mode inductor D28, a second common-mode inductor D29, a third operational amplifier U3B, a fifth capacitor C14, a sixth capacitor C15, a seventh capacitor C35, a twenty-third resistor R25, a twenty-fourth resistor R26, a twenty-fifth resistor R27, a twenty-sixth resistor R108, a twenty-seventh resistor R109, and a twenty-eighth resistor R110; the second connector J7 has two pins. Both pins of the second connector J7 are electrically connected to the liquid level sensor. The second pin of the second connector J7 is also electrically connected to the +12V power supply terminal through the first common-mode inductor D28, and the common pin of the first common-mode inductor D28 is grounded. The first pin of the second connector J7 is also electrically connected to the non-inverting input pin of the third operational amplifier U3B through the second common-mode inductor D29 and the twenty-third resistor R25, and the common pin of the second common-mode inductor D29 is grounded. The first terminal of the seventh capacitor C35 and the first terminal of the twenty-seventh resistor R109 are connected to the common connection terminal between the first pin of the second connector J7 and the second common-mode inductor D29, and the second terminals of the seventh capacitor C35 and the twenty-seventh resistor R109 are both grounded. The power supply pin of the third operational amplifier U3B is electrically connected to the 5V power supply terminal, and the first terminal of the fifth capacitor C14 is connected to the power supply terminal of the third operational amplifier U3B. The second end of the fifth capacitor C14 is grounded at the common connection between the source pin and the 5V power supply terminal; the ground pin of the third operational amplifier U3B is grounded; the first end of the twenty-sixth resistor R108 is connected to the common connection between the twenty-third resistor R25 and the non-inverting input pin of the third operational amplifier U3B, and the second end of the twenty-sixth resistor R108 is grounded; the inverting input pin of the third operational amplifier U3B is grounded through the twenty-fifth resistor R27, and the inverting input pin of the third operational amplifier U3B is also electrically connected to the output pin of the third operational amplifier U3B through the twenty-eighth resistor R110; the output pin of the third operational amplifier U3B is electrically connected to the input terminal of the main control board through the twenty-fourth resistor R26, the first end of the sixth capacitor C15 is connected to the common connection between the twenty-fourth resistor R26 and the input terminal of the main control board, and the second end of the sixth capacitor C15 is grounded.

[0086] In the analog liquid level detection circuit designed above, the liquid level sensor is the core component, responsible for sensing changes in the liquid level of the sewage pump and converting the liquid level information into an electrical signal. The second connector J7 acts as a bridge connecting the liquid level sensor and subsequent circuits, ensuring smooth signal transmission. The first common-mode inductor D28 and the second common-mode inductor D29 are mainly used to suppress common-mode interference, improve the circuit's anti-interference capability, and ensure the accuracy and stability of the liquid level signal. The seventh capacitor C35 and the twenty-seventh resistor R109 form a simple filter circuit to further filter the signal output from the liquid level sensor, removing high-frequency noise and spurious signals, making the signal entering the subsequent operational amplifier circuit cleaner. The third operational amplifier U3B, as a key component for signal amplification and processing, amplifies the weak liquid level signal after filtering, bringing it to a voltage range that can be recognized and processed by the main control board. The fifth capacitor C14 is connected between the power supply pin of the third operational amplifier U3B and ground, acting as a power decoupling agent, providing a stable power supply to the operational amplifier, and reducing the impact of power fluctuations on the operational amplifier's operation.

[0087] Resistors R108 (26th), R27 (25th), and R110 (28th) together form the feedback network of the operational amplifier. By appropriately setting the values ​​of these resistors, the amplification factor and operating state of the operational amplifier can be adjusted to meet the needs of different liquid level detection. Resistor R26 (24th) acts as a current-limiting resistor, limiting the current from the operational amplifier output to the main control board input, preventing excessive current from damaging the main control board. Capacitor C15 (6th) is connected between resistor R26 (24th) and the main control board input, serving as DC blocking and filtering to further ensure the quality of the liquid level voltage signal transmitted to the main control board.

[0088] The analog liquid level detection circuit designed here can convert the 4~20mA analog liquid level signal input from the liquid level sensor into a liquid level voltage signal and transmit it to the main control board. Based on the received liquid level voltage signal, the main control board, combined with preset algorithms and control logic, precisely controls the sewage pump to achieve effective sewage treatment and discharge, ensuring the normal operation of the entire sewage treatment system.

[0089] Specifically, such as Figure 9 As shown, the digital liquid level detection circuit includes a liquid level switch (not shown in the figure), a fourth connector J8, a third optocoupler U17, a fourth optocoupler U8, an eighth capacitor C10, a ninth capacitor C40, a twenty-ninth resistor R39, a thirtieth resistor R40, a thirty-first resistor R41, a thirty-second resistor R70, a thirty-third resistor R71, and a thirty-fourth resistor R73; the fourth connector J8 has 5 pins; The first, second, and third pins of the fourth connector J8 are all electrically connected to the level switch, and the third pin of the fourth connector J8 is also grounded; the fourth pin of the fourth connector J8 is electrically connected to the negative input terminal of the fourth optocoupler U8 through the thirty-first resistor R41, and the fifth pin of the fourth connector J8 is electrically connected to the negative input terminal of the third optocoupler U17 through the thirty-fourth resistor R73; the first end of the thirty-third resistor R71 is electrically connected to the +12V power supply terminal, and the second end of the thirty-third resistor R71 and the first end of the ninth capacitor C40 are both connected to the common connection terminal between the fifth pin of the fourth connector J8 and the thirty-fourth resistor R73, and the second end of the ninth capacitor C40 is grounded; the thirtieth resistor R4... The first terminal of 0 is electrically connected to the +12V power supply terminal. The second terminal of the thirtieth resistor R40 and the first terminal of the eighth capacitor C10 are both connected to the common connection terminal between the fourth pin of the fourth connector J8 and the thirty-first resistor R41. The second terminal of the eighth capacitor C10 is grounded. The output collector of the third optocoupler U17 and the output collector of the fourth optocoupler U8 are both electrically connected to the input terminal of the main control board. The output collector of the third optocoupler U17 is also electrically connected to the circuit power supply terminal through the thirty-second resistor R70. The output collector of the fourth optocoupler U8 is also electrically connected to the circuit power supply terminal through the twenty-ninth resistor R39. The output emitter of the third optocoupler U17 and the output emitter of the fourth optocoupler U8 are both grounded.

[0090] The digital liquid level detection circuit in the above-mentioned backup detection mode uses a liquid level switch as the core detection component. The liquid level switch can generate a corresponding switching signal according to the change of liquid level. When the liquid level reaches the set threshold, the liquid level switch will close or open, thereby changing the on / off state of the circuit. Therefore, it is specifically a two-level liquid level detection circuit.

[0091] In the aforementioned digital liquid level detection circuit, the fourth connector J8 connects the liquid level switch and the subsequent optocoupler circuit, bridging the signal transmission. Resistors R41 (31) and R73 (34) limit the current input to the fourth optocoupler U8 and the third optocoupler U17, respectively, preventing excessive current from damaging the optocoupler components. Resistors R40 (30) and R71 (33) provide appropriate bias voltage to the input side of the optocouplers, ensuring their normal operation. Capacitors C10 (8) and C40 (9) act as filters, removing interference and noise from the signal, making the signal input to the optocouplers more stable. Optocouplers U17 (3) and U8 (4) serve as key components for signal isolation and conversion, converting the liquid level switch's switching signal into a digital signal and transmitting it to the main control board. The output collector of the optocoupler is electrically connected to the input of the main control board. When current flows through the input of the optocoupler, the output collector conducts, and the main control board receives a low-level signal; when no current flows through the input, the output collector does not conduct, and the main control board receives a high-level signal. Resistors R70 (32nd) and R39 (29th) act as pull-up resistors, ensuring that the input level of the main control board remains stable at a high level when the output collector of the optocoupler is not conducting, thus guaranteeing accurate signal transmission. When the level switch closes or opens, the conduction state of the optocoupler changes, and the level signal transmitted to the input of the main control board changes accordingly. The main control board uses these digital signals to determine whether the liquid level has reached the preset conditions for starting or stopping the sewage pump.

[0092] This digital liquid level detection circuit features a simple structure and high reliability. It can promptly take over when the analog liquid level detection circuit fails, providing essential liquid level information for the sewage pump control. Even in complex industrial environments affected by electromagnetic interference, the digital liquid level detection circuit can stably output switching signals, ensuring the basic operation of the sewage pump intelligent control system and providing crucial protection for the safety and stability of the entire sewage treatment system.

[0093] Preferably, such as Figure 2 As shown, the fault indication unit includes a buzzer control circuit and an external alarm control circuit; The input terminals of the buzzer control circuit and the external alarm control circuit are both electrically connected to the output terminal of the main control board, and the output terminal of the external alarm control circuit is electrically connected to the external alarm device. The buzzer control circuit is used to receive a first alarm command issued by the main control board when the main control board determines that the sewage pump has a motor failure and / or a liquid level failure, and to issue a buzzer signal according to the first alarm command. The external alarm control circuit is used to receive a second alarm command issued by the main control board when the main control board determines that the sewage pump has a motor failure and / or a liquid level failure, and to issue an alarm signal through the external alarm device according to the second alarm command.

[0094] Upon receiving the first alarm command, the buzzer control circuit drives the buzzer to generate a buzzing signal with a specific frequency and rhythm. Upon receiving the second alarm command, the external alarm control circuit transmits the signal to an external alarm device, which then issues the alarm. Through these fault indication units, the intelligent sewage pump control system can promptly alert operators in various application scenarios when a fault occurs. Operators can quickly locate the type and location of the fault and take appropriate repair measures based on the received alarm signal.

[0095] This embodiment integrates a fault indication unit with a dual-mode liquid level detection unit, a motor overheat detection circuit, a phase current detection circuit, a phase voltage detection circuit, and a zero-crossing detection circuit to form a complete fault early warning and handling system. When a detection circuit detects an abnormality, the main control board can promptly determine the fault type and issue an alarm through the fault indication unit, ensuring the stable operation and efficient management of the entire sewage pump intelligent control system.

[0096] In practical applications, different buzzer signals can be set according to different fault types. For example, a fast and continuous buzzer sound is used for motor faults, while a slightly longer intermittent buzzer sound is used for liquid level faults. This allows operators to quickly determine the approximate type of fault through sound characteristics.

[0097] External alarm devices can be audible and visual alarms, emitting an alarm sound while flashing warning lights to attract the attention of those nearby. Especially in noisy industrial environments, light signals can effectively compensate for the inability of sound signals to be easily masked, further improving the efficiency of fault information transmission.

[0098] Specifically, such as Figure 10 As shown, the buzzer control circuit includes a first relay K1, a buzzer, a fifth connector J19, a second diode D14, a third diode D15, a fourth diode D16, a thirty-fifth resistor R68, and a thirty-sixth resistor R107; the fifth connector J19 has two pins. The positive terminal of the coil power supply of the first relay K1 is electrically connected to the circuit power supply terminal, and the negative terminal of the coil power supply of the first relay K1 is electrically connected to the output terminal of the main control board. The common terminal of the coil of the first relay K1 is grounded. The first normally open contact of the first relay K1 is left floating. The second normally open contact of the first relay K1 is electrically connected to the negative input terminal of the buzzer through the thirty-seventh resistor R107. The positive input terminal of the buzzer is electrically connected to the +12V power supply terminal through the second diode D14. The anode of the fourth diode D16 is connected to the common connection terminal between the thirty-seventh resistor R107 and the negative input terminal of the buzzer. The cathode of the fourth diode D16 and the third diode D16 are connected to the common connection terminal between the thirty-seventh resistor R107 and the negative input terminal of the buzzer. The negative terminal of diode D15 and the first end of the 35th resistor R68 are both connected to the common connection terminal between the positive input terminal of the buzzer and the second diode D14; the positive terminal of the third diode D15 and the second end of the 35th resistor R68 are both electrically connected to the 9V power supply terminal; the first pin of the fifth connector J19 is electrically connected to the positive terminal of the external battery box, and the first pin of the fifth connector J19 is also connected to the common connection terminal between the positive terminal of the third diode D15, the second end of the 35th resistor R68 and the 9V power supply terminal; the second pin of the fifth connector J19 is electrically connected to the negative terminal of the external battery box, and the second pin of the fifth connector J19 is also grounded.

[0099] In the buzzer control circuit designed above, when the main control board determines that the sewage pump has a motor fault and / or a liquid level fault, it will output a signal to the negative terminal of the coil of the first relay K1, energizing the coil of the first relay K1 and closing its normally open contact. At this time, the current reaches the negative input terminal of the buzzer through the closed second normally open contact and the thirty-seventh resistor R107. The second diode D14 provides a +12V power supply voltage to the positive input terminal of the buzzer and also prevents reverse current flow, protecting the circuit components. The fourth diode D16 acts as a clamp in the circuit to prevent the voltage at the negative input terminal of the buzzer from being too high and damaging the buzzer. The combination of the third diode D15 and the thirty-fifth resistor R68 provides a 9V power supply path for the buzzer. This dual power supply method ensures that the buzzer can work normally under different power supply environments. When the +12V power supply fails, the 9V power supply can still provide the necessary power to the buzzer. The fifth connector J19 is used to connect an external battery box to provide additional power support for the circuit. When the external power supply fails or becomes unstable, the external battery box can serve as a backup power source to ensure the normal operation of the buzzer control circuit, thereby ensuring that a buzzer signal can be issued in a timely manner when a fault occurs.

[0100] Through the circuit design of the buzzer control circuit described above, the buzzer control circuit can quickly drive the buzzer to emit a specific buzzing signal after receiving the first alarm command issued by the main control board, providing timely fault warnings to the operators. At the same time, this circuit has multiple power supply guarantees and protection measures, improving the reliability and stability of the entire fault indication unit, and further enhancing the safety and efficiency of the sewage pump intelligent control system.

[0101] Specifically, such as Figure 11 As shown, the external alarm control circuit includes a second relay K2 and a sixth connector J9; the sixth connector J9 has 3 pins; The positive terminal of the coil power supply of the second relay K2 is electrically connected to the +12V power supply terminal, the negative terminal of the coil power supply of the second relay K2 is electrically connected to the output terminal of the main control board, and the common terminal of the coil of the second relay K2 is electrically connected to the second pin of the first connector; the first normally open contact of the second relay K2 is electrically connected to the first pin of the sixth connector J9, and the second normally open contact of the second relay K2 is electrically connected to the third pin of the sixth connector J9; all three pins of the sixth connector J9 are also electrically connected to the external alarm device.

[0102] In the external alarm control circuit designed above, when the main control board determines that the sewage pump has a motor fault and / or a liquid level fault, it will output a signal to the negative terminal of the coil of the second relay K2, energizing the coil of the second relay K2 and closing its normally open contact. At this time, the circuit is connected, and the current can be transmitted to the sixth connector J9 through the closed normally open contact, and then transmitted to the external alarm device. The external alarm device can be of various types, such as an audible and visual alarm. Upon receiving the control signal from the main control board, the audible and visual alarm will immediately emit an alarm sound and flash warning lights simultaneously.

[0103] The external alarm control circuit works in conjunction with the aforementioned buzzer control circuit to form a multi-layered fault alarm system. When the sewage pump intelligent control system detects a fault, the buzzer control circuit first alerts nearby operators with a buzzer signal, while the external alarm control circuit uses external alarm devices such as audible and visual alarms to issue a warning to a wider range of people, informing more people about the fault. This combined alarm method can quickly transmit fault information in different usage scenarios, buying valuable repair time for operators, ensuring that the sewage pump intelligent control system can promptly resume normal operation, guaranteeing the continuous and stable operation of the sewage treatment system, and preventing environmental pollution caused by sewage discharge problems.

[0104] The aforementioned external alarm control circuit can be multi-channel, and can be connected to external alarm devices for different scenarios. Figure 11Only one external alarm control circuit is shown; the structural design of the other external alarm control circuits is the same and will not be shown here.

[0105] Preferably, such as Figure 2 As shown, the system also includes a functional expansion unit; The functional expansion unit is electrically connected to the main control board; The functional expansion unit is used to provide auxiliary functions to the sewage pump under the control of the main control board.

[0106] The auxiliary functions provided by the functional expansion unit enable more intelligent operation of the sewage pump, making the intelligent control system of the sewage pump more flexible, efficient and intelligent, better adaptable to different application scenarios and user needs, and further improving the performance and reliability of the entire sewage treatment system.

[0107] Preferably, such as Figure 2 As shown, the motor in the sewage pump is equipped with a motor power supply circuit; the functional expansion unit includes a contactor control circuit. The input terminal of the contactor control circuit is electrically connected to the output terminal of the main control board, and the output terminal of the contactor control circuit is electrically connected to the motor power supply circuit. The contactor control circuit is used to receive a contactor control signal sent by the main control board when the main control board determines that the sewage pump has a motor failure, and to cut off the motor power supply circuit according to the contactor control signal; it is also used to obtain the contactor trigger action corresponding to the motor power supply circuit, and to cut off the motor power supply circuit according to the contactor trigger action.

[0108] When the contactor control circuit receives a contactor control signal from the main control board, it quickly responds and executes the operation of cutting off the motor power supply circuit, thereby promptly preventing the faulty motor from continuing to run. This contactor control circuit not only improves the reliability and stability of the system but also effectively reduces maintenance costs and repair time. By promptly cutting off the power supply to the faulty motor, it reduces the additional losses caused by the motor's malfunction and extends the motor's service life.

[0109] Furthermore, the contactor control circuit can also be linked with other detection circuits and control units in the system. For example, when the liquid level detection circuit detects an abnormal liquid level, the main control board can cut off the motor power supply circuit through the contactor control circuit to prevent the sewage pump from operating under abnormal liquid levels, thereby protecting the motor and the entire sewage treatment system. Simultaneously, when the motor overheat detection circuit detects that the motor temperature is too high, the contactor control circuit can also quickly cut off the motor power supply to prevent damage due to overheating. Through this linkage mechanism, the intelligent sewage pump control system can form an organic whole, with each part cooperating and complementing each other to jointly ensure the efficient operation of the sewage treatment system.

[0110] Specifically, such as Figure 12 As shown, the contactor control circuit includes contactor T2, third relay K6, first contactor soldering hole JP7, second contactor soldering hole JP8, first transistor Q2, fifth diode D23, thirty-seventh resistor R78 and thirty-eighth resistor R81; The base of the first transistor Q2 is electrically connected to the output terminal of the main control board through the thirty-seventh resistor R78. The emitter of the first transistor Q2 is grounded. The first end of the thirty-eighth resistor R81 is connected to the common connection terminal between the base of the first transistor Q2 and the thirty-seventh resistor R78, and the second end of the thirty-eighth resistor R81 is grounded. The collector of the first transistor Q2 is electrically connected to the negative terminal of the coil power supply of the third relay K6. The positive terminal of the coil power supply of the third relay K6 is electrically connected to the +12V power supply terminal. The anode of the fifth diode D23 is connected to the common connection terminal between the collector of the first transistor Q2 and the negative terminal of the coil power supply of the third relay K6. The cathode of the fifth diode D23 is connected to the common connection terminal between the positive terminal of the coil power supply of the third relay K6 and the +12V power supply terminal. The stationary contact of the third relay K6 is electrically connected to the phase line of the motor power supply circuit through the contactor T2. The normally closed moving contact of the third relay K6 is electrically connected to the first end of the first contactor welding hole JP7. The second end of the first contactor welding hole JP7 is electrically connected to the first end of the second contactor welding hole JP8. The second end of the second contactor welding hole JP8 is grounded.

[0111] In the contactor control circuit of the above circuit design, when the main control board determines that the sewage pump motor has failed and sends a contactor control signal, the signal is transmitted to the base of the first transistor Q2 through the 37th resistor R78. At this time, the first transistor Q2 conducts, energizing the coil of the third relay K6. Since the stationary contact of the third relay K6 is connected to the phase line of the motor power supply circuit through contactor T2, its normally closed moving contact opens when the coil of the third relay K6 is energized. After the normally closed moving contact opens, the motor power supply circuit is cut off, and the motor stops running, thus avoiding more serious damage that might be caused by the continued operation of the faulty motor. The fifth diode D23 plays a protective role in the circuit. When the coil of the third relay K6 is de-energized, it can provide a discharge path for the energy stored in the coil, preventing the generation of back electromotive force that could damage other components in the circuit.

[0112] The first contactor soldering hole JP7 and the second contactor soldering hole JP8 facilitate circuit connection and debugging. In practical applications, the contactor control circuit can be tested and maintained through these two soldering holes. Simultaneously, the grounded second contactor soldering hole JP8 ensures circuit safety, preventing injury to operators due to electrical leakage or other problems.

[0113] Preferably, such as Figure 2 As shown, the functional expansion unit also includes a serial communication interface circuit; The output terminal of the serial communication interface circuit is electrically connected to the input terminal of the main control board; The main control board is also used to communicate serially with external bus devices through the serial communication interface circuit, and to receive serial commands from the external bus devices to perform medium-distance control of the sewage pump.

[0114] Through a serial communication interface circuit, the intelligent control system for sewage pumps enables medium-distance control and management, greatly improving the system's flexibility and applicability. Operators can operate and monitor the sewage pumps from a distance, reducing the workload and risks of on-site operations, improving work efficiency and safety, and further enhancing the automation and intelligence level of the entire sewage treatment system.

[0115] In this embodiment, the serial communication interface circuit can be an RS485 communication interface circuit, which includes an RS485 transceiver U7, common cathode diodes D26 and D27, connector J5, inductors L6 and L7, capacitors C8, C33, and C34, resistors R40, R104, R105, and R106. The specific connection relationships between the electronic components are as follows: Figure 13 As shown.

[0116] Of course, the serial communication interface circuit can also be other types of interface circuits, such as RS232 communication interface circuits, CAN communication interface circuits, etc. A suitable interface circuit can be selected according to the actual situation; its specific form and circuit design are not limited in this embodiment.

[0117] Preferably, such as Figure 2 As shown, the functional expansion unit also includes a memory circuit and a clock circuit; Both the memory circuit and the clock circuit are electrically connected to the main control board.

[0118] The memory circuit is used to store various data during the operation of the intelligent control system for the sewage pump, such as motor operating parameters, fault records, and liquid level data. By analyzing the stored data, operators can easily understand the operating status of the sewage pump, promptly identify potential problems, and take corresponding measures to address them, thereby improving the stability and reliability of the system.

[0119] The clock circuit provides accurate time information to the system. In the intelligent sewage pump control system, the system can set the sewage pump's operating time and perform timed data acquisition and processing based on the time information. Simultaneously, the clock circuit can also provide timestamps for fault recording and data storage, facilitating subsequent data analysis and management. Through these designs, the intelligent sewage pump control system can maintain reliable performance during long-term operation, effectively ensuring the normal operation of the sewage treatment system.

[0120] Specifically, the clock circuit in this embodiment includes a timing chip U18, diodes D17 and D18, capacitors C16, C36, and C37, a bias resistor P1, and a battery BAT1. The specific connection relationships between the electronic components are as follows: Figure 14 As shown.

[0121] Specifically, the memory circuit refers to an external storage circuit that is independent of the main control board (which has a built-in memory). It includes a memory chip U24, capacitor C20, resistors R63 and R64, and the specific connections between these electronic components are as follows: Figure 15 As shown.

[0122] In this embodiment, the electronic components in each circuit module can be selected according to the appropriate specifications and models based on the actual situation, which will not be listed here.

[0123] This embodiment Figure 2 The complete intelligent control system for sewage pumps shown has the following beneficial effects: (1) Intelligent and networked management has been achieved, significantly improving operation and maintenance efficiency: By integrating three modes—near-range HMI control, mid-range RS485 bus networking, and long-range WiFi IoT control—users can flexibly choose the control method according to the scenario. Operation and maintenance personnel can monitor the water pump status in real time, receive fault alarms, and perform remote control through a mobile APP or host computer without being physically present on-site. This greatly reduces the cost of manual inspection, improves fault response speed and management efficiency, and strongly supports the implementation of "smart water management".

[0124] (2) A modular, separate structure is adopted, optimizing product reliability, maintainability, and user experience: The HMI control panel (including buttons, display, and WiFi module) is physically separated from the main control board and connected by cables. This design not only improves space utilization and enhances WiFi signal strength but also makes the interface layout more user-friendly. Each functional unit is connected to the main control board in a star topology, resulting in low coupling. Failure of any module will not affect other functions, and the faulty module can be directly replaced during maintenance, reducing maintenance difficulty and cost.

[0125] (3) A multi-layered motor protection system combining hardware and software was constructed, greatly improving equipment safety and lifespan: It integrates real-time detection of phase current, phase voltage, and motor temperature, and has an automatic power supply type identification function. The main control board's software algorithm realizes comprehensive protection against overcurrent, overvoltage, undervoltage, and overload, while an independent hardware protection circuit (such as overheat hardware cutoff) achieves the highest priority rapid response. This dual protection mechanism fundamentally avoids motor damage due to abnormal operating conditions and significantly extends the service life of core equipment.

[0126] (4) Equipped with highly adaptable dual-mode liquid level detection, enhancing environmental applicability and reliability: It provides a high-precision 4~20mA analog liquid level detection channel and a simple and reliable two-stage switch detection channel. Users can flexibly choose according to the type of sensor on site and cost budget, improving the controller's adaptability to different engineering scenarios. The dual modes serve as backups for each other, also improving the overall fault tolerance of the liquid level detection system.

[0127] (5) It integrates a wealth of extended functions and interfaces, improving the system's integration and flexibility: time management is achieved through an external clock, on-site parameter configuration is achieved through DIP switches and potentiometers, standard industrial networking is achieved through an RS485 interface, and external alarm devices are driven through relay outputs. These functional extensions enable the controller not only to work independently but also to be easily integrated into larger monitoring systems, meeting the needs of complex application scenarios.

[0128] (6) While achieving multi-functional integration, it maintains a compact design and solves the contradiction between intelligence and size: Through highly integrated circuit design and modular separation structure, it integrates functions that traditionally require multiple independent devices in a small space, successfully overcoming the defects of large size and high cost that exist in existing intelligent controllers, and is particularly suitable for small and medium-sized sewage pump application scenarios with limited space.

[0129] Example 2 A method for intelligent control of a sewage pump, wherein the sewage pump is controlled by the intelligent control system of embodiment one; like Figure 16 As shown, the method includes: S1: Using the main control board, user commands are received through the button module in the HMI control panel to manually control the sewage pump; or wireless communication is established with a remote terminal through the wireless communication module in the HMI control panel to receive remote commands from the remote terminal to remotely control the sewage pump. S2: When the main control board controls the sewage pump, the motor protection unit collects key electrical parameters of the motor configured in the sewage pump in real time and transmits the collected key electrical parameters to the main control board in real time; the dual-mode liquid level detection unit collects the first liquid level signal of the sewage pump in the main detection mode and transmits the first liquid level signal to the main control board; or collects the second liquid level signal of the sewage pump in the backup detection mode and transmits the second liquid level signal to the main control board; wherein the first liquid level signal and the second liquid level signal are different; S3: Using the main control board, determine whether the sewage pump has a motor failure based on the key electrical parameters; and determine whether the sewage pump has a liquid level failure based on the first liquid level signal or the second liquid level signal. S4: When the main control board determines that the sewage pump has a motor failure and / or a liquid level failure, it uses the fault prompt module to issue a fault prompt signal.

[0130] In this embodiment, during the control of the sewage pump, the button module on the HMI control panel, which is independent of the main control board, allows for manual control of the sewage pump. This facilitates operators in adjusting the pump's operating status on-site according to actual conditions. Furthermore, the wireless communication module on the HMI control panel enables wireless communication with a remote terminal, allowing the receipt of remote commands and remote control of the sewage pump, thus improving the flexibility and convenience of pump control. Whether in manual or remote control mode, when the main control board controls the sewage pump, it can issue corresponding operating commands to the motor protection unit and the dual-mode liquid level detection unit. The motor protection unit can collect key electrical parameters of the motor in the sewage pump in real time and transmit them to the main control board. The main control board can then adjust the pump's operation based on these parameters. The system can simultaneously determine whether the motor has malfunctioned. At the same time, the dual-mode liquid level detection unit can acquire the liquid level information of the sewage pump (including a first liquid level signal or a second liquid level signal). The main control board uses this liquid level information to determine whether a liquid level fault has occurred. The dual-mode liquid level detection unit provides a main detection mode and a backup detection mode, capable of collecting different forms of liquid level signals. This dual-mode design increases the reliability of liquid level detection; even if the main detection mode malfunctions, the backup detection mode can continue to operate, ensuring that the main control board can accurately acquire the liquid level information of the sewage pump, thereby determining whether a liquid level fault has occurred. When the main control board determines that the sewage pump has experienced a motor fault and / or a liquid level fault, the fault indication module will issue a fault indication signal to promptly remind relevant personnel to handle the situation, preventing the fault from escalating and reducing equipment damage and maintenance costs.

[0131] The intelligent control method for sewage pumps in this embodiment realizes comprehensive intelligent and automated control of sewage pumps, effectively improving the stability and reliability of sewage pump operation. The entire control system is compact in design, cost-controllable, and fully functional, and supports remote monitoring in multiple ways. It can better adapt to various complex sewage discharge environments, improve sewage discharge efficiency, ensure the smooth progress of sewage treatment work, and provide strong support for the efficient operation and sustainable development of the sewage treatment industry.

[0132] The intelligent control system for the sewage pump described in this embodiment has the same structure as the intelligent control system for the sewage pump in Embodiment 1. Therefore, for details not covered in this embodiment, please refer to Embodiment 1 and... Figures 1 to 15 The specific details will not be repeated here.

[0133] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An intelligent control system for a sewage pump, characterized in that, The system includes a main control board, an HMI control panel, a motor protection unit, a dual-mode liquid level detection unit, and a fault indication unit; The HMI control panel includes a wireless communication module and a button module that are independent of the main control board; wherein, the wireless communication module is communicatively connected to the main control board, and the button module is electrically connected to the main control board; the motor protection unit, the dual-mode liquid level detection unit, and the fault indication unit are all electrically connected to the main control board; The main control board is used to receive user commands through the button module in the HMI control panel to manually control the sewage pump; it is also used to communicate wirelessly with a remote terminal through the wireless communication module to receive remote commands from the remote terminal to remotely control the sewage pump. The motor protection unit is used to collect key electrical parameters of the motor configured in the sewage pump in real time when the main control board controls the sewage pump, and transmit the collected key electrical parameters to the main control board in real time. The dual-mode liquid level detection unit has a main detection mode and a backup detection mode. When the main control board controls the sewage pump, it acquires a first liquid level signal from the sewage pump according to the main detection mode and transmits the first liquid level signal to the main control board. It is also used when the main control board controls the sewage pump, it acquires a second liquid level signal from the sewage pump according to the backup detection mode and transmits the second liquid level signal to the main control board. The first liquid level signal and the second liquid level signal are different. The main control board is also used to receive the key electrical parameters transmitted by the motor protection unit, and determine whether the sewage pump has a motor failure based on the key electrical parameters; it is also used to receive the first liquid level signal or the second liquid level signal transmitted by the dual-mode liquid level detection unit, and determine whether the sewage pump has a liquid level failure based on the first liquid level signal or the second liquid level signal. The fault indication module is used to issue a fault indication signal when the main control board determines that the sewage pump has a motor fault and / or a liquid level fault.

2. The intelligent control system for sewage pumps according to claim 1, characterized in that, The motor in the sewage pump is equipped with a motor power supply circuit, and the key electrical parameters include the motor phase current signal and the motor phase voltage signal in the motor power supply circuit; The motor protection unit includes a phase current detection circuit and a phase voltage detection circuit. The input terminals of the phase current detection circuit and the phase voltage detection circuit are both electrically connected to the motor power supply circuit. The output terminals of the phase current detection circuit and the phase voltage detection circuit are both electrically connected to the input terminal of the main control board. The phase current detection circuit is used to collect the motor phase current signal in the motor power supply circuit and transmit the motor phase current signal to the main control board; The phase voltage detection circuit is used to collect the motor phase voltage signal in the motor power supply circuit and transmit the motor phase voltage signal to the main control board.

3. The intelligent control system for sewage pumps according to claim 2, characterized in that, The phase current detection circuit includes a current transformer U11, a first operational amplifier U12A, a first diode bridge rectifier, a first electrolytic capacitor C30, a first capacitor C7, a first resistor R5, a second resistor R6, a third resistor R7, a fourth resistor R37, a fifth resistor R38, and a sixth resistor R103. The primary side of current transformer U11 is electrically connected to one phase line of the motor power supply circuit, and the secondary side of current transformer U11 is electrically connected to the input terminal of the first diode bridge rectifier. The negative terminal of the output terminal of the first diode bridge rectifier is grounded. The positive terminal of the output terminal of the first diode bridge rectifier is electrically connected to the non-inverting input pin of the first operational amplifier U12A through the first resistor R5. The positive terminal of the first electrolytic capacitor C30 and the first terminal of the sixth resistor R103 are both connected to the common connection terminal between the positive terminal of the output terminal of the first diode bridge rectifier and the first resistor R5. The negative terminal of the first electrolytic capacitor C30 and the second terminal of the sixth resistor R103 are both grounded. The first terminal of the fourth resistor R37 is connected to the first... A resistor R5 is connected to the common connection between the non-inverting input pin of the first operational amplifier U12A, and the second end of the fourth resistor R37 is grounded; the power supply pin of the first operational amplifier U12A is electrically connected to the circuit power supply terminal, and the sibling pins of the first operational amplifier U12A are grounded; the inverting input pin of the first operational amplifier U12A is grounded through the third resistor R7, and is also electrically connected to the output pin of the first operational amplifier U12A through the fifth resistor R38; the output pin of the first operational amplifier U12A is electrically connected to the input terminal of the main control board through the second resistor R6; the first end of the first capacitor C7 is connected to the common connection between the second resistor R6 and the input terminal of the main control board, and the second end of the first capacitor C7 is grounded.

4. The intelligent control system for sewage pumps according to claim 2, characterized in that, The phase voltage detection circuit includes a transformer U23, a second operational amplifier U14A, a second diode bridge rectifier, a second electrolytic capacitor C31, a second capacitor C5, a third capacitor C6, a seventh resistor R1, an eighth resistor R2, a ninth resistor R3, a tenth resistor R4, an eleventh resistor R34, a twelfth resistor R36, and a thirteenth resistor R99. The first terminal of the primary side of transformer U13 is electrically connected to one phase line of the motor power supply circuit through the thirteenth resistor R33, and the second terminal of the primary side of transformer U13 is electrically connected to the reference point of the motor power supply circuit; the secondary side of transformer U13 is electrically connected to the input terminal of the second diode bridge rectifier; the negative terminal of the output terminal of the second diode bridge rectifier is grounded; the positive terminal of the output terminal of the second diode bridge rectifier is electrically connected to the non-inverting input pin of the second operational amplifier U14A through the seventh resistor R1; the positive terminal of the second electrolytic capacitor C31 and the first terminal of the eighth resistor R2 are both connected to the common connection terminal between the positive terminal of the output terminal of the second diode bridge rectifier and the seventh resistor R1; the negative terminal of the second electrolytic capacitor C31 and the second terminal of the eighth resistor R2 are both grounded; the first terminal of the eleventh resistor R34 is connected to the seventh resistor R1. The second end of the eleventh resistor R34 is grounded on the common connection terminal between the non-inverting input pin of the second operational amplifier U14A and the common connection terminal between the non-inverting input pin of the second operational amplifier U14A and the 5V power supply terminal. The ground pin of the second operational amplifier U14A is grounded. The inverting input pin of the second operational amplifier U14A is grounded through the tenth resistor R4 and is also electrically connected to the output pin of the second operational amplifier U14A through the twelfth resistor R36. The output pin of the second operational amplifier U14A is electrically connected to the input terminal of the main control board through the ninth resistor R3. The first end of the second capacitor C5 is connected to the common connection terminal between the ninth resistor R3 and the input terminal of the main control board, and the second end of the second capacitor C5 is grounded.

5. The intelligent control system for sewage pumps according to claim 2, characterized in that, The key electrical parameters also include a temperature detection signal used to characterize the motor temperature; The motor protection unit also includes a motor overheat detection circuit, the output of which is electrically connected to the input of the main control board. The motor overheat detection circuit is used to collect temperature detection signals from the motor and transmit the temperature detection signals to the main control board.

6. The intelligent control system for sewage pumps according to claim 5, characterized in that, The motor overheat detection circuit includes a temperature sensor, a first connector J12, a first optocoupler U15, a fourth capacitor C38, a fourteenth resistor R28, a fifteenth resistor R65, a sixteenth resistor R66, and a seventeenth resistor R67; the first connector J12 has two pins; the temperature sensor is located on the motor. The first and second pins of the first connector J12 are both electrically connected to the output terminal of the temperature sensor. The first pin of the first connector J12 is also electrically connected to the +12V power supply terminal through the fifteenth resistor R65. The second pin of the first connector J12 is also electrically connected to the positive input terminal of the first optocoupler U15. The first end of the fourth capacitor C38 and the first end of the sixteenth resistor R66 are both connected to the common connection terminal between the second pin of the first connector J12 and the positive input terminal of the first optocoupler U15. The second end of the fourth capacitor C38 and the second end of the sixteenth resistor R66 are both grounded. The negative input terminal of the first optocoupler U15 is grounded. The collector of the output side of the first optocoupler U15 is electrically connected to the +3.3V power supply terminal. The collector-emitter of the output side of the first optocoupler U15 is electrically connected to the input terminal of the main control board through the fourteenth resistor R28. The first end of the seventeenth resistor R67 is connected to the common connection terminal between the collector-emitter of the output side of the first optocoupler U15 and the fourteenth resistor R28. The second end of the seventeenth resistor R67 is grounded.

7. The intelligent control system for sewage pumps according to claim 2, characterized in that, The key electrical parameters also include the digital pulse signal generated when the power supply voltage in the motor power supply circuit crosses zero; The motor protection unit also includes two identical zero-crossing detection circuits. The input terminals of the two zero-crossing detection circuits are electrically connected to different phase lines of the motor power supply circuit, and the output terminals of the two zero-crossing detection circuits are electrically connected to the input terminal of the main control board. Each zero-crossing detection circuit is used to detect the digital pulse signal generated when the phase voltage in the corresponding phase line crosses zero, and transmits the digital pulse signal to the main control board. The main control board is used to compare the phase difference between the two received digital pulse signals and identify whether the motor power supply circuit is a single-phase power supply or a three-phase power supply based on the phase difference.

8. The intelligent control system for sewage pumps according to claim 7, characterized in that, Each of the zero-crossing detection circuits includes a second optocoupler, a first diode, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, and a twenty-second resistor; In each of the zero-crossing detection circuits, the first end of the nineteenth resistor and the first end of the twenty-first resistor are both coupled to the phase line corresponding to the motor power supply circuit. The second end of the nineteenth resistor is connected to the positive input terminal of the second optocoupler through the twentieth resistor and the first diode in sequence. The second end of the twenty-first resistor is connected to the negative input terminal of the second optocoupler through the twenty-second resistor. The collector of the output side of the second optocoupler is connected to the input terminal of the main control board. The collector of the output side of the second optocoupler is also connected to the +3.3V power supply terminal through the eighteenth resistor. The emitter of the output side of the second optocoupler is grounded.

9. The intelligent control system for sewage pumps according to claim 1, characterized in that, The first liquid level signal is specifically an analog liquid level signal, and the second liquid level signal is specifically a digital liquid level signal; The dual-mode liquid level detection unit includes an analog liquid level detection circuit and a digital liquid level detection circuit, both of which are electrically connected to the input terminal of the main control board. The analog liquid level detection circuit is used to collect the analog liquid level signal of the sewage pump, and convert the analog liquid level signal into a liquid level voltage signal and transmit it to the main control board. The digital liquid level detection circuit is used to collect the digital liquid level signal of the sewage pump and transmit the digital liquid level signal to the main control board.

10. The intelligent control system for sewage pumps according to claim 9, characterized in that, The analog liquid level detection circuit includes a liquid level sensor, a second connector J7, a first common-mode inductor D28, a second common-mode inductor D29, a third operational amplifier U3B, a fifth capacitor C14, a sixth capacitor C15, a seventh capacitor C35, a twenty-third resistor R25, a twenty-fourth resistor R26, a twenty-fifth resistor R27, a twenty-sixth resistor R108, a twenty-seventh resistor R109, and a twenty-eighth resistor R110; the second connector J7 has two pins. Both pins of the second connector J7 are electrically connected to the liquid level sensor. The second pin of the second connector J7 is also electrically connected to the +12V power supply terminal through the first common-mode inductor D28, and the common pin of the first common-mode inductor D28 is grounded. The first pin of the second connector J7 is also electrically connected to the non-inverting input pin of the third operational amplifier U3B through the second common-mode inductor D29 and the twenty-third resistor R25, and the common pin of the second common-mode inductor D29 is grounded. The first terminal of the seventh capacitor C35 and the first terminal of the twenty-seventh resistor R109 are connected to the common connection terminal between the first pin of the second connector J7 and the second common-mode inductor D29, and the second terminals of the seventh capacitor C35 and the twenty-seventh resistor R109 are both grounded. The power supply pin of the third operational amplifier U3B is electrically connected to the 5V power supply terminal, and the first terminal of the fifth capacitor C14 is connected to the power supply terminal of the third operational amplifier U3B. The second end of the fifth capacitor C14 is grounded at the common connection between the source pin and the 5V power supply terminal; the ground pin of the third operational amplifier U3B is grounded; the first end of the twenty-sixth resistor R108 is connected to the common connection between the twenty-third resistor R25 and the non-inverting input pin of the third operational amplifier U3B, and the second end of the twenty-sixth resistor R108 is grounded; the inverting input pin of the third operational amplifier U3B is grounded through the twenty-fifth resistor R27, and the inverting input pin of the third operational amplifier U3B is also electrically connected to the output pin of the third operational amplifier U3B through the twenty-eighth resistor R110; the output pin of the third operational amplifier U3B is electrically connected to the input terminal of the main control board through the twenty-fourth resistor R26, the first end of the sixth capacitor C15 is connected to the common connection between the twenty-fourth resistor R26 and the input terminal of the main control board, and the second end of the sixth capacitor C15 is grounded.

11. The intelligent control system for sewage pumps according to claim 9, characterized in that, The digital liquid level detection circuit includes a liquid level switch, a fourth connector J8, a third optocoupler U17, a fourth optocoupler U8, an eighth capacitor C10, a ninth capacitor C40, a twenty-ninth resistor R39, a thirtieth resistor R40, a thirty-first resistor R41, a thirty-second resistor R70, a thirty-third resistor R71, and a thirty-fourth resistor R73; the fourth connector J8 has 5 pins. The first, second, and third pins of the fourth connector J8 are all electrically connected to the level switch, and the third pin of the fourth connector J8 is also grounded; the fourth pin of the fourth connector J8 is electrically connected to the negative input terminal of the fourth optocoupler U8 through the thirty-first resistor R41, and the fifth pin of the fourth connector J8 is electrically connected to the negative input terminal of the third optocoupler U17 through the thirty-fourth resistor R73; the first end of the thirty-third resistor R71 is electrically connected to the +12V power supply terminal, and the second end of the thirty-third resistor R71 and the first end of the ninth capacitor C40 are both connected to the common connection terminal between the fifth pin of the fourth connector J8 and the thirty-fourth resistor R73, and the second end of the ninth capacitor C40 is grounded; the thirtieth resistor R4... The first terminal of 0 is electrically connected to the +12V power supply terminal. The second terminal of the thirtieth resistor R40 and the first terminal of the eighth capacitor C10 are both connected to the common connection terminal between the fourth pin of the fourth connector J8 and the thirty-first resistor R41. The second terminal of the eighth capacitor C10 is grounded. The output collector of the third optocoupler U17 and the output collector of the fourth optocoupler U8 are both electrically connected to the input terminal of the main control board. The output collector of the third optocoupler U17 is also electrically connected to the circuit power supply terminal through the thirty-second resistor R70. The output collector of the fourth optocoupler U8 is also electrically connected to the circuit power supply terminal through the twenty-ninth resistor R39. The output emitter of the third optocoupler U17 and the output emitter of the fourth optocoupler U8 are both grounded.

12. The intelligent control system for sewage pumps according to claim 1, characterized in that, The fault indication unit includes a buzzer control circuit and an external alarm control circuit; The input terminals of the buzzer control circuit and the external alarm control circuit are both electrically connected to the output terminal of the main control board, and the output terminal of the external alarm control circuit is electrically connected to the external alarm device. The buzzer control circuit is used to receive a first alarm command issued by the main control board when the main control board determines that the sewage pump has a motor failure and / or a liquid level failure, and to issue a buzzer signal according to the first alarm command. The external alarm control circuit is used to receive a second alarm command issued by the main control board when the main control board determines that the sewage pump has a motor failure and / or a liquid level failure, and to issue an alarm signal through the external alarm device according to the second alarm command.

13. The intelligent control system for sewage pumps according to claim 12, characterized in that, The buzzer control circuit includes a first relay K1, a buzzer, a fifth connector J19, a second diode D14, a third diode D15, a fourth diode D16, a thirty-fifth resistor R68, and a thirty-sixth resistor R107; the fifth connector J19 has two pins. The positive terminal of the coil power supply of the first relay K1 is electrically connected to the circuit power supply terminal, and the negative terminal of the coil power supply of the first relay K1 is electrically connected to the output terminal of the main control board. The common terminal of the coil of the first relay K1 is grounded. The first normally open contact of the first relay K1 is left floating. The second normally open contact of the first relay K1 is electrically connected to the negative input terminal of the buzzer through the thirty-seventh resistor R107. The positive input terminal of the buzzer is electrically connected to the +12V power supply terminal through the second diode D14. The anode of the fourth diode D16 is connected to the common connection terminal between the thirty-seventh resistor R107 and the negative input terminal of the buzzer. The cathode of the fourth diode D16 and the third diode D16 are connected to the common connection terminal between the thirty-seventh resistor R107 and the negative input terminal of the buzzer. The negative terminal of diode D15 and the first end of the 35th resistor R68 are both connected to the common connection terminal between the positive input terminal of the buzzer and the second diode D14; the positive terminal of the third diode D15 and the second end of the 35th resistor R68 are both electrically connected to the 9V power supply terminal; the first pin of the fifth connector J19 is electrically connected to the positive terminal of the external battery box, and the first pin of the fifth connector J19 is also connected to the common connection terminal between the positive terminal of the third diode D15, the second end of the 35th resistor R68 and the 9V power supply terminal; the second pin of the fifth connector J19 is electrically connected to the negative terminal of the external battery box, and the second pin of the fifth connector J19 is also grounded.

14. The intelligent control system for sewage pumps according to claim 12, characterized in that, The external alarm control circuit includes a second relay K2 and a sixth connector J9; the sixth connector J9 has 3 pins; The positive terminal of the coil power supply of the second relay K2 is electrically connected to the +12V power supply terminal, the negative terminal of the coil power supply of the second relay K2 is electrically connected to the output terminal of the main control board, and the common terminal of the coil of the second relay K2 is electrically connected to the second pin of the first connector; the first normally open contact of the second relay K2 is electrically connected to the first pin of the sixth connector J9, and the second normally open contact of the second relay K2 is electrically connected to the third pin of the sixth connector J9; all three pins of the sixth connector J9 are also electrically connected to the external alarm device.

15. The intelligent control system for sewage pumps according to claim 1, characterized in that, The HMI control panel also includes a display module; The display module is communicatively connected to the main control board; The display module is used to receive display commands issued by the main control board when the main control board controls the sewage pump, so as to display and control the sewage pump.

16. The intelligent control system for sewage pumps according to claim 1, characterized in that, The system also includes a functional expansion unit; The functional expansion unit is electrically connected to the main control board; The functional expansion unit is used to provide auxiliary functions to the sewage pump under the control of the main control board.

17. The intelligent control system for sewage pumps according to claim 16, characterized in that, The motor in the sewage pump is equipped with a motor power supply circuit; the functional expansion unit includes a contactor control circuit. The input terminal of the contactor control circuit is electrically connected to the output terminal of the main control board, and the output terminal of the contactor control circuit is electrically connected to the motor power supply circuit. The contactor control circuit is used to receive a contactor control signal sent by the main control board when the main control board determines that the sewage pump has a motor failure, and to cut off the motor power supply circuit according to the contactor control signal; it is also used to obtain the contactor trigger action corresponding to the motor power supply circuit, and to cut off the motor power supply circuit according to the contactor trigger action.

18. The intelligent control system for sewage pumps according to claim 17, characterized in that, The contactor control circuit includes contactor T2, third relay K6, first contactor soldering hole JP7, second contactor soldering hole JP8, first transistor Q2, fifth diode D23, thirty-seventh resistor R78 and thirty-eighth resistor R81; The base of the first transistor Q2 is electrically connected to the output terminal of the main control board through the thirty-seventh resistor R78. The emitter of the first transistor Q2 is grounded. The first end of the thirty-eighth resistor R81 is connected to the common connection terminal between the base of the first transistor Q2 and the thirty-seventh resistor R78, and the second end of the thirty-eighth resistor R81 is grounded. The collector of the first transistor Q2 is electrically connected to the negative terminal of the coil power supply of the third relay K6. The positive terminal of the coil power supply of the third relay K6 is electrically connected to the +12V power supply terminal. The anode of the fifth diode D23 is connected to the common connection terminal between the collector of the first transistor Q2 and the negative terminal of the coil power supply of the third relay K6. The cathode of the fifth diode D23 is connected to the common connection terminal between the positive terminal of the coil power supply of the third relay K6 and the +12V power supply terminal. The stationary contact of the third relay K6 is electrically connected to the phase line of the motor power supply circuit through the contactor T2. The normally closed moving contact of the third relay K6 is electrically connected to the first end of the first contactor welding hole JP7. The second end of the first contactor welding hole JP7 is electrically connected to the first end of the second contactor welding hole JP8. The second end of the second contactor welding hole JP8 is grounded.

19. The intelligent control system for sewage pumps according to claim 16, characterized in that, The functional expansion unit also includes a serial communication interface circuit; The output terminal of the serial communication interface circuit is electrically connected to the input terminal of the main control board; The main control board is also used to communicate serially with external bus devices through the serial communication interface circuit, and to receive serial commands from the external bus devices to perform medium-distance control of the sewage pump.

20. The intelligent control system for sewage pumps according to claim 16, characterized in that, The functional expansion unit also includes a memory circuit and a clock circuit; Both the memory circuit and the clock circuit are electrically connected to the main control board.

21. A method for intelligent control of a sewage pump, characterized in that, The sewage pump is controlled by an intelligent control system for sewage pumps as described in any one of claims 1 to 20; The method includes: The sewage pump can be manually controlled by receiving user commands through the button module in the HMI control panel using the main control board; or it can be remotely controlled by receiving remote commands from the remote terminal through the wireless communication module in the HMI control panel. When the main control board controls the sewage pump, the motor protection unit collects key electrical parameters of the motor configured in the sewage pump in real time and transmits the collected key electrical parameters to the main control board in real time; the dual-mode liquid level detection unit collects the first liquid level signal of the sewage pump in the main detection mode and transmits the first liquid level signal to the main control board; or collects the second liquid level signal of the sewage pump in the backup detection mode and transmits the second liquid level signal to the main control board; wherein the first liquid level signal and the second liquid level signal are different. Using the main control board, it is determined whether the sewage pump has a motor failure based on the key electrical parameters; and it is determined whether the sewage pump has a liquid level failure based on the first liquid level signal or the second liquid level signal. When the main control board determines that the sewage pump has a motor failure and / or a liquid level failure, it uses the fault indication module to issue a fault indication signal.

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