Professional frequency converter control circuit for driving water pump

Abstract

The utility model discloses a professional frequency converter control circuit for driving a water pump. The frequency converter comprises a main control chip U1, a switching value input interface circuit, a relay output interface circuit, an RS485 communication interface circuit, a CAN communication interface circuit, a frequency converter PWM drive circuit, a PTC signal acquisition interface circuit, an analog quantity acquisition interface circuit, an analog quantity output interface circuit, a buffer circuit and a monitoring circuit. According to the utility model, a professional frequency converter control circuit is combined with a plurality of functional modules, and accurate control and optimal adjustment of a water pump driving system are realized through the 32-bit DSP main control chip. The system has the advantages of being improved in performance, reduced in cost, improved in cost performance, convenient to produce, clean, environmentally friendly and the like, so that the system has higher stability, reliability and economical efficiency, is suitable for various industrial application scenes, and brings more convenient, reliable and efficient use experience for users.

Description

Technical Field

[0001] The utility model relates to the technical field of intelligent water pumps, in particular to a professional frequency converter control circuit for driving water pumps. Background Art

[0002] At present, inverter-driven water pumps have become a common energy-saving measure in the industrial field. By combining the inverter with the water pump, the water pump system can be accurately controlled to meet the needs of different working conditions. This technology has been widely used in industrial production, water supply, heating, air conditioning and other fields. However, this technology still inevitably has some problems, such as:

[0003] Higher cost: The price of the inverter itself is relatively high, especially in small water pump applications, the cost of the inverter may account for a large proportion, resulting in an increase in initial investment.

[0004] Difficulty of technical maintenance: As an electrical control device, the inverter requires professional technicians to install, debug and maintain it. Some small enterprises or non-professional users may face difficulties in technical application and maintenance.

[0005] Failure rate and stability: As a control device, the failure rate and stability of the inverter are crucial to the operation of the system. Some low-quality or inappropriate inverters may have high failure rates and poor stability, affecting the normal operation of the system.

[0006] Impact on the power grid: The inverter-driven water pump may cause harmonics and voltage instability in the power grid during the speed regulation process. It is necessary to consider the impact of the power grid during the design and use process and take corresponding compensation measures.

[0007] In general, inverter-driven water pump technology is an important technology developed based on the needs of industrial automation and energy conservation. It achieves efficient use of energy and reduced operating costs by adjusting the speed of the water pump. However, although this technology is widely used in industrial production and water supply, there are still many challenges, such as high cost, difficult technical maintenance, electromagnetic interference problems, failure rate and stability, and impact on the power grid. These defects limit the promotion and application scope of this technology, and further research and improvement are needed to solve them. Summary of the invention

[0008] According to an embodiment of the utility model, a professional inverter control circuit for water pump driving is provided, comprising:

[0009] Main control chip, used for real-time control and signal processing;

[0010] A switch quantity input interface circuit is connected to the main control chip and is used for isolating and transmitting input signals;

[0011] Relay output interface circuit, the relay output interface circuit is connected to the main control chip and is used to control external electrical equipment;

[0012] RS485 communication interface circuit, the RS485 communication interface circuit is connected to the main control chip for communication;

[0013] CAN communication interface circuit, the CAN communication interface circuit is connected to the main control chip for data transmission;

[0014] The inverter PWM drive circuit is connected to the main control chip and is used to generate a PWM signal to adjust the voltage and frequency output by the external inverter;

[0015] A PTC signal acquisition interface circuit is connected to the main control chip and is used to process and convert analog signals from external PTC sensors;

[0016] Analog quantity acquisition interface circuit, the analog quantity acquisition interface circuit is connected to the main control chip and is used for collecting and converting analog quantities;

[0017] Analog output interface circuit, the analog output interface is connected to the main control chip and is used to process, convert and output analog signals;

[0018] A buffer circuit, which is connected to the main control chip and is used to amplify, buffer and transmit input signals;

[0019] The monitoring circuit is connected to the main control chip and is used to monitor the power supply of the main control chip.

[0020] Further, the PTC signal acquisition interface circuit includes: a first operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first switch diode, a sixth resistor, a first capacitor, a seventh resistor, a second operational amplifier, an eighth resistor, a ninth resistor, a tenth resistor, a second switch diode, an eleventh resistor, a twelfth resistor, a third capacitor and a second capacitor;

[0021] The non-inverting input terminal of the first operational amplifier is connected to the external PTCP interface through the first resistor, and the inverting input terminal of the first operational amplifier is connected to the external PTCN interface through the second resistor and the third resistor;

[0022] One end of the fourth resistor and the fifth resistor is connected to the +4V-P interface, the other end of the fourth resistor is connected between the first resistor and the external PTCP interface, and the other end of the fifth resistor is connected between the second resistor and the third resistor;

[0023] The pin 3 of the first switch diode, the output end of the first operational amplifier, one end of the sixth resistor and one end of the seventh resistor are connected;

[0024] The other end of the sixth resistor is connected to the inverting input end of the first operational amplifier, and the first capacitor is connected in parallel with the sixth resistor;

[0025] The non-inverting input terminal of the second operational amplifier is connected to the other end of the seventh resistor, the output terminal of the second operational amplifier is connected to one end of the ninth resistor, and the inverting input terminal of the second operational amplifier is connected to the other end of the ninth resistor and then connected to one end of the tenth resistor;

[0026] The pin 3 of the second switch diode, the other end of the tenth resistor, the eleventh resistor and one end of the second capacitor are connected;

[0027] One end of the twelfth resistor is connected to the other end of the tenth resistor, and the other end of the twelfth resistor, the other end of the second capacitor, and one end of the third capacitor are grounded;

[0028] The eleventh resistor is connected to the other end of the third capacitor and then connected to the main control chip.

[0029] Furthermore, the PTC signal acquisition interface circuit further comprises: a thirteenth resistor and a fourth capacitor;

[0030] One end of the thirteenth resistor and the fourth capacitor is grounded, the other end of the thirteenth resistor and the fourth capacitor is connected to the non-inverting input terminal of the first operational amplifier, and the other end of the thirteenth resistor is located between the non-inverting input terminal of the first operational amplifier and the other end of the fourth capacitor.

[0031] Further, the analog quantity acquisition interface circuit includes: a first connector, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a third operational amplifier, a third switch diode, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a fifth capacitor, a sixth capacitor, a seventh capacitor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, a fourth switch diode, an eighth capacitor and a ninth capacitor;

[0032] The first connector is connected to the non-inverting input terminal of the third operational amplifier through the fourteenth resistor, the fifteenth resistor, and the sixteenth resistor in sequence;

[0033] The seventeenth resistor, the eighteenth resistor, and the nineteenth resistor are connected in series to the ground in sequence, and one end of the seventeenth resistor is connected between the fourteenth resistor and the fifteenth resistor;

[0034] One end of the fifth capacitor is connected between the seventeenth resistor and the fifteenth resistor, and the other end is grounded;

[0035] One end of the sixth capacitor and the pin 3 of the third switch diode are connected between the fifteenth resistor and the sixteenth resistor, and the other end of the sixth capacitor is grounded;

[0036] One end of the seventh capacitor is connected between the non-inverting input terminal of the third operational amplifier and the sixteenth resistor, and the other end is grounded;

[0037] The output terminal of the third operational amplifier is connected to the inverting input terminal of the third operational amplifier and one end of the twentieth resistor;

[0038] The 20th resistor, the 21st resistor and the 22nd resistor are connected in series in sequence;

[0039] One end of the twenty-third resistor is connected between one end of the twenty-first resistor and one end of the twenty-second resistor;

[0040] Pin 3 of the fourth switch diode and one end of the eighth capacitor are both connected between one end of the twenty-third resistor and one end of the twenty-second resistor;

[0041] The other end of the eighth capacitor, the other end of the twenty-third resistor, and one end of the ninth capacitor are grounded;

[0042] The other end of the ninth capacitor and the other end of the twenty-second resistor are connected to the main control chip.

[0043] Further, the analog output interface circuit includes: a twenty-fourth resistor, a twenty-fifth resistor, a fourth operational amplifier, a twenty-sixth resistor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, a twenty-seventh resistor, a twenty-eighth resistor, a twenty-ninth resistor, a thirtieth resistor, a thirty-first resistor, a fifth operational amplifier, a thirty-second resistor, a thirteenth capacitor, a thirty-third resistor, a thirty-fourth resistor, a thirty-fifth resistor, a thirty-sixth resistor, a first triode, a second connector, a fourteenth capacitor, and a fifth switch diode;

[0044] The non-inverting input terminal of the fourth operational amplifier is connected to the main control chip through the twenty-fourth resistor and the twenty-fifth resistor in sequence, and the inverting input terminal of the fourth operational amplifier is connected to one end of the twenty-seventh resistor, the twenty-eighth resistor, and the twenty-ninth resistor.

[0045] One end of the twenty-sixth resistor is connected to the main control chip, and the other end is grounded;

[0046] One end of the tenth capacitor and one end of the eleventh capacitor are both connected between the twenty-fourth resistor and the twenty-fifth resistor, and the other end of the tenth capacitor is grounded;

[0047] One end of the twelfth capacitor is connected between the twenty-fourth resistor and the non-inverting input terminal of the fourth operational amplifier, and the other end is grounded;

[0048] The other ends of the twenty-seventh resistor and the twenty-eighth resistor are grounded;

[0049] One end of the 30th resistor is connected to the output end of the fourth operational amplifier, and the other end of the 30th resistor is connected to the other end of the 11th capacitor and the 29th resistor;

[0050] One end of the thirty-first resistor is connected to pin 1 of the second connector and one end of the thirteenth capacitor, and then connected between the other end of the thirtieth resistor and the other end of the eleventh capacitor;

[0051] The non-inverting input terminal of the fifth operational amplifier is connected to the other end of the thirty-first resistor, the inverting input terminal of the fifth operational amplifier is connected to the thirty-second resistor and one end of the thirty-third resistor, and the output terminal of the fifth operational amplifier is connected to the base of the first transistor through the thirty-fourth resistor;

[0052] The other end of the thirty-second resistor and the other end of the thirteenth capacitor are grounded;

[0053] The collector of the first transistor is connected to the +15V interface, and the emitter of the first transistor is connected to the other end of the thirty-third resistor and one end of the thirty-fifth resistor;

[0054] One end of the thirty-sixth resistor, the other end of the thirty-fifth resistor, and the pin 3 of the second connector are connected, and the other end of the thirty-sixth resistor is connected between the non-inverting input terminal of the fifth operational amplifier and the other end of the thirty-first resistor;

[0055] The pin 2 of the second connector, one end of the fourteenth capacitor, the pin 3 of the fifth switch diode and the external output interface are connected;

[0056] The other end of the fourteenth capacitor is grounded.

[0057] Further, the monitoring circuit includes: a thirty-seventh resistor, a thirty-eighth resistor, a fifteenth capacitor, a monitoring chip, a sixteenth capacitor, a thirty-ninth resistor, a seventeenth capacitor, a fortieth resistor, a forty-first resistor, an eighteenth capacitor, a nineteenth capacitor, and an inverter;

[0058] One end of the thirty-seventh resistor is connected to the 3.3V voltage, and the other end of the thirty-seventh resistor is grounded through the thirty-eighth resistor and connected to the pin 4 of the monitoring chip;

[0059] One end of the fifteenth capacitor is connected between the pin 4 of the monitoring chip and one end of the thirty-eighth resistor, and the fifteenth capacitor is grounded;

[0060] One end of the sixteenth capacitor is connected to pin 3 of the monitoring chip and is grounded, and the other end of the sixteenth capacitor is connected to a 5V voltage and one end of the thirty-ninth resistor;

[0061] The other end of the thirty-ninth resistor is connected to the pin 7 of the monitoring chip and then grounded through the seventeenth capacitor;

[0062] Pin 8 of the monitoring chip is connected to one end of the inverter through a 40th resistor;

[0063] After one end of the forty-first resistor is connected to one end of the eighteenth capacitor, it is connected between the pin 8 of the monitoring chip and the fortieth resistor, and the other end of the forty-first resistor and the other end of the eighteenth capacitor are grounded;

[0064] One end of a nineteenth capacitor is connected between the fortieth resistor and one end of the inverter, and the other end is grounded;

[0065] The other end of the inverter is connected to the main control chip.

[0066] According to the embodiment of the utility model, a professional inverter control circuit for water pump driving is combined with a variety of functional modules, and the precise control and optimization adjustment of the water pump driving system is realized through the 32-bit DSP main control chip. Its advantages of improved performance, reduced cost, improved cost performance, convenient production, clean and environmentally friendly make the system have higher stability, reliability and economy, and it is suitable for various industrial application scenarios, bringing users a more convenient, reliable and efficient use experience. The details are as follows:

[0067] 1. Performance improvement: Using professional 32-bit DSP as the main control chip, combined with a variety of functional modules, it realizes precise control and optimization of the water pump drive system, and improves the performance of the system. For example: through the design of analog output circuit and PWM drive circuit, it can realize precise control of the water pump motor, and improve the operation stability and response speed of the system.

[0068] 2. Cost reduction: Comprehensive design of multiple functional modules, such as optocoupler input interface, relay output interface, communication interface, etc., realizes linkage control and data communication of external devices, reduces the system's dependence on external additional devices, and reduces the system's cost and maintenance expenses.

[0069] 3. Improved cost performance: By comprehensively considering the design and integration of various functional modules, the functions of the water pump drive system have been comprehensively improved, which has significantly improved the cost performance of the system. Compared with the traditional drive system, this solution is not only more powerful, but also more cost-effective and more cost-effective.

[0070] 4. Convenient production: It uses a variety of common chips and components, such as TL074, LM339, MAX708, etc. These components are easy to purchase and assemble, which is conducive to the management and control of the production process and improves production efficiency.

[0071] 5. Clean and environmentally friendly: The use of digital signal processing and communication interfaces reduces dependence on traditional analog signal lines, reduces electromagnetic interference and the complexity of cable wiring, is conducive to improving the reliability and stability of the system, and is also in line with the development trend of clean and environmental protection.

[0072] It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the technology as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 The present invention is a circuit diagram of a main control chip of a professional inverter control circuit for driving a water pump according to an embodiment of the present utility model.

[0074] Figure 2 The present invention is a circuit diagram of a switch quantity input interface circuit of a professional frequency converter control circuit for driving a water pump according to an embodiment of the present utility model.

[0075] Figure 3 The present invention is a circuit diagram of a relay output interface circuit of a professional inverter control circuit for driving a water pump according to an embodiment of the present utility model.

[0076] Figure 4 The present invention is a circuit diagram of an RS485 communication interface circuit of a professional frequency converter control circuit for driving a water pump according to an embodiment of the present invention.

[0077] Figure 5 The present invention is a circuit diagram of a CAN communication interface circuit of a professional inverter control circuit for driving a water pump according to an embodiment of the present utility model.

[0078] Figure 6 The present invention is a circuit diagram of a frequency converter PWM drive circuit of a professional frequency converter control circuit for driving a water pump according to an embodiment of the present utility model.

[0079] Figure 7 The present invention is a circuit diagram of a PTC signal acquisition interface circuit of a professional inverter control circuit for driving a water pump according to an embodiment of the present utility model.

[0080] Figure 8 The present invention is a circuit diagram of an analog quantity acquisition interface circuit of a professional frequency converter control circuit for driving a water pump according to an embodiment of the present utility model.

[0081] Fig. 9 The present invention is a circuit diagram of an analog output interface circuit of a professional frequency converter control circuit for driving a water pump according to an embodiment of the present utility model.

[0082] Fig.10The present invention is a circuit diagram of a buffer circuit of a professional frequency converter control circuit for driving a water pump according to an embodiment of the present utility model.

[0083] Fig.11 The present invention is a circuit diagram of a monitoring circuit of a professional frequency converter control circuit for driving a water pump according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0084] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings to further illustrate the present invention.

[0085] First, combine Figures 1 to 11 A professional inverter control circuit for driving a water pump according to an embodiment of the utility model is described, which is used for intelligent control of the water pump and has a wide range of application scenarios.

[0086] like Figures 1 to 11 As shown, a professional inverter control circuit for water pump driving in an embodiment of the utility model has a main control chip U1, a switch input interface circuit, a relay output interface circuit, an RS485 communication interface circuit, a CAN communication interface circuit, an inverter PWM drive circuit, a PTC signal acquisition interface circuit, an analog quantity acquisition interface circuit, an analog quantity output interface circuit, a buffer circuit and a monitoring circuit.

[0087] like Figure 1 As shown, the main control chip U1 is used for real-time control and signal processing. In this embodiment, the DSP chip model selected by this application is TMS320F28034, which is mainly used to realize real-time control and signal processing tasks. TMS320F28034 has a built-in high-performance 32-bit fixed-point DSP core, which can execute complex algorithms and operations, and has the characteristics of high-speed operation and low power consumption. The chip has built-in flash memory (Flash) and random access memory (RAM) for storing program code, data and intermediate results, so that developers can easily store and access programs. In addition, TMS320F28034 provides a variety of peripheral interfaces, including analog input / output interface, digital input / output interface, universal serial interface (SPI), universal asynchronous receiver / transmitter (UART), etc., which is convenient for connecting external sensors, actuators and other devices. The chip integrates multiple high-precision clock and timer modules to realize accurate time measurement, timing control and timing triggering functions to meet the needs of real-time control systems. In addition, the chip also uses advanced low-power design technology, which can minimize power consumption while achieving high-performance computing tasks, extending the battery life of the system or reducing energy consumption.

[0088] like Figure 2As shown, the switch input interface circuit is connected to the main control chip U1 for isolation and transmission of input signals. In this embodiment, a four-channel optocoupler (LTV357) is used, which mainly realizes isolation protection and electrical isolation of input signals to prevent external interference from damaging the control circuit. It converts the input signal into an optical signal and transmits it to the output end through a photoelectric converter to achieve signal isolation and transmission. This interface can be used to detect the switch state or signal change of external devices and trigger corresponding operations or events of the control system.

[0089] like Figure 3 As shown, the relay output interface circuit is connected to the main control chip U1 for controlling external electrical equipment. In this embodiment, the design of the relay output interface usually plays an important role in the control circuit. It is mainly used for various electrical equipment in the control circuit, such as motors, lamps, heaters, etc. By turning on and off the contacts of the relay, precise switching control of these devices can be achieved. In addition, the relay output interface also provides an electrical isolation function to isolate the control circuit from the controlled circuit to prevent interference and protect the circuit. The relay has a high load capacity and can withstand large currents and voltages. It is suitable for various occasions with high load requirements. Most importantly, the relay output interface can be used as a protection device for the control circuit. When the controlled device fails or is overloaded, the relay can quickly cut off the power supply to prevent damage to the control circuit and ensure the safety and stable operation of the system.

[0090] like Figure 4 As shown, the RS485 communication interface circuit is connected to the main control chip U1 for communication. In this embodiment, the RS485 interface usually plays an important role in the control system. It can realize long-distance communication, covering a range of hundreds of meters or even thousands of meters, so it is widely used in industrial control systems. The RS485 interface adopts differential signal transmission, has strong anti-interference ability, and can effectively resist electromagnetic interference and noise. In addition, RS485 supports multi-point communication, and multiple devices can be connected to the same communication line for communication, realizing flexible interconnection between devices. It is usually half-duplex communication, which simplifies the communication protocol and hardware design and improves the communication efficiency. As an industrial standardized communication interface, the RS485 communication interface is compatible with various industrial equipment and control systems, and has mature communication protocols and rich application experience. In summary, the RS485 communication interface designed based on the SN75176 chip provides a reliable communication solution for industrial automation and data acquisition.

[0091] like Figure 5As shown, the CAN communication interface circuit is connected to the main control chip U1 for data transmission. In this embodiment, the CAN communication interface designed based on the SN65HVD230DR chip is a high-speed and reliable serial communication protocol. It can achieve high-speed data transmission, has good real-time performance, and can quickly respond to the instructions and data transmission requests of the control system. It also has strong anti-interference ability, can effectively resist electromagnetic interference and noise, and ensure the stability and reliability of communication signals. The CAN communication interface supports long-distance transmission, covering a range of hundreds of meters or even thousands of meters, and is suitable for large control systems or distributed control systems. In addition, it also supports communication between multiple devices, realizes flexible interconnection between devices, and is suitable for complex control systems or networked control systems. In general, the CAN communication interface designed based on the SN65HVD230DR chip provides a stable and reliable solution for data communication of the control system, and is an indispensable part of industrial control and automotive electronic systems.

[0092] like Figure 6 As shown, the inverter PWM drive circuit is connected to the main control chip U1, which is used to generate PWM signals to adjust the voltage and frequency of the external inverter output. In this embodiment, the inverter PWM drive circuit designed based on LM339 plays an important role in the inverter system. Its main function is to generate PWM signals, and adjust the voltage and frequency of the inverter output by controlling the width of these pulse signals, thereby realizing accurate speed control of loads such as motors. LM339 is a four-way comparator with the characteristics of multi-way input, high gain and high speed, which is very suitable for the generation and control of PWM signals. In this PWM drive circuit, the working principle of LM339 is to compare the input feedback signal with the reference voltage, and generate a PWM signal according to the comparison result. The reference voltage is usually provided by a voltage divider circuit, and the size of the reference voltage can be adjusted by adjusting the resistance value in the voltage divider circuit, thereby adjusting the duty cycle of the PWM signal. In this way, the PWM signal generated by LM339 is sent to the inverter, controlling the voltage and frequency of the inverter output, thereby realizing accurate control of the motor speed. By adjusting the duty cycle of the PWM signal, the motor speed can be continuously adjusted. When the duty cycle of the PWM signal increases, the average voltage output by the inverter also increases, and the motor speed increases accordingly; conversely, when the duty cycle of the PWM signal decreases, the motor speed decreases. This precise speed regulation function makes the PWM drive circuit designed by LM339 widely used in industrial control systems.

[0093] like Figure 7As shown, the PTC signal acquisition interface circuit is connected to the main control chip U1, and is used to process and convert the analog signal from the external PTC sensor. The PTC signal acquisition interface circuit includes: a first operational amplifier U20A, a first resistor R281, a second resistor R280, a third resistor R278, a fourth resistor R279, a fifth resistor R274, a first switch diode D9, a sixth resistor R291, a first capacitor C164, a seventh resistor R288, a second operational amplifier U20D, an eighth resistor, a ninth resistor R290, a tenth resistor R292, a second switch diode D31, an eleventh resistor R118, a twelfth resistor R291, a third capacitor C134 and a second capacitor C164. 67; the non-inverting input terminal of the first operational amplifier U20A is connected to the external PTCP interface through the first resistor R281, and the inverting input terminal of the first operational amplifier U20A is connected to the external PTCN interface through the second resistor R280 and the third resistor R278; one end of the fourth resistor R279 and the fifth resistor R274 are connected to the +4V-P interface, the other end of the fourth resistor R279 is connected between the first resistor R281 and the external PTCP interface, and the other end of the fifth resistor R274 is connected to the second resistor R280 and the third resistor R278 The pin 3 of the first switching diode D9, the output end of the first operational amplifier U20A, one end of the sixth resistor R291 and one end of the seventh resistor R288 are connected; the other end of the sixth resistor R291 is connected to the inverting input end of the first operational amplifier U20A, and the first capacitor C164 is connected in parallel with the sixth resistor R291; the non-inverting input end of the second operational amplifier U20D is connected to the other end of the seventh resistor R288, the output end of the second operational amplifier U20D is connected to one end of the ninth resistor R290, and the inverting The input end is connected to the other end of the ninth resistor R290 and then to one end of the tenth resistor R292; the pin 3 of the second switching diode D31, the other end of the tenth resistor R292, the eleventh resistor R118 and one end of the second capacitor C167 are connected; one end of the twelfth resistor R291 is connected to the other end of the tenth resistor R292, and the other end of the twelfth resistor R291, the other end of the second capacitor C167, and one end of the third capacitor C134 are grounded; the eleventh resistor R118 is connected to the other end of the third capacitor C134 and then to the main control chip U1. Furthermore, the PTC signal acquisition interface circuit also includes: a thirteenth resistor R287 and a fourth capacitor C161; one end of the thirteenth resistor R287 and the fourth capacitor C161 is grounded, the other end of the thirteenth resistor R287 and the fourth capacitor C161 is connected to the non-inverting input terminal of the first operational amplifier U20A, and the other end of the thirteenth resistor R287 is located between the non-inverting input terminal of the first operational amplifier U20A and the other end of the fourth capacitor C161.In this embodiment, the interface for collecting PTC signals designed based on TL074IDR plays a very important role in the control system. Its main function is to process and convert the analog signal from the PTC sensor so that the control system can correctly identify and process it. As a four-way operational amplifier, TL074IDR has the ability to amplify, filter and convert signals. In the PTC signal acquisition interface, it can achieve the following functions: First, TL074IDR can amplify the weak signal from the PTC sensor to a level that the control system can handle. Through the appropriate amplification factor, the accurate acquisition and processing of the sensor signal can be ensured. Secondly, TL074IDR can apply filtering and denoising technology to eliminate noise and interference in the sensor signal. This helps to improve the quality and stability of the signal and ensure that the system can accurately read the output of the sensor. In addition, TL074IDR can also realize signal conversion, converting analog signals into digital signals for further processing and analysis by the control system. In addition, TL074IDR can also provide sensor protection function. By designing an appropriate protection circuit, the sensor can be prevented from being damaged by overvoltage, overcurrent, etc., and the service life of the sensor can be extended.

[0094] like Figure 8As shown, the analog quantity acquisition interface circuit is connected to the main control chip U1 for collecting and converting analog quantities. The analog quantity acquisition interface circuit includes: a first connector J6, a fourteenth resistor R75, a fifteenth resistor R74, a sixteenth resistor R70, a third operational amplifier U11D, a third switch diode D2, a seventeenth resistor R77, an eighteenth resistor R79, a nineteenth resistor R78, a fifth capacitor C42, a sixth capacitor C41, a seventh capacitor C40, a twentieth resistor R67, a twenty-first resistor R68, a twenty-second resistor R69, a twenty-third resistor R76, a fourth switch diode D1, an eighth capacitor C38, and The ninth capacitor C39; the first connector J6 is connected to the in-phase input terminal of the third operational amplifier U11D through the fourteenth resistor R75, the fifteenth resistor R74, and the sixteenth resistor R70 in sequence; the seventeenth resistor R77, the eighteenth resistor R79, and the nineteenth resistor R78 are connected to the ground in series in sequence, and one end of the seventeenth resistor R77 is connected between the fourteenth resistor R75 and the fifteenth resistor R74; one end of the fifth capacitor C42 is connected between the seventeenth resistor R77 and the fifteenth resistor R74, and the other end is grounded; the sixth capacitor C4 The first terminal of the second switching diode D1 and the pin 3 of the third switching diode D2 are connected between the fifteenth resistor R74 and the sixteenth resistor R70, and the other end of the sixth capacitor C41 is grounded; one end of the seventh capacitor C40 is connected between the non-inverting input terminal of the third operational amplifier U11D and the sixteenth resistor R70, and the other end is grounded; the output end of the third operational amplifier U11D is connected to the inverting input terminal of the third operational amplifier U11D and one end of the twentieth resistor R67; the twentieth resistor R67, the twenty-first resistor R68, and the twenty-second resistor R69 are connected in series in sequence; one end of the twenty-third resistor R76 is connected between the twenty-first resistor R68 and one end of the twenty-second resistor R69; the pin 3 of the fourth switching diode D1 and one end of the eighth capacitor C38 are connected between one end of the twenty-third resistor R76 and one end of the twenty-second resistor R69; the other end of the eighth capacitor C38, the other end of the twenty-third resistor R76, and one end of the ninth capacitor C39 are grounded; the other end of the ninth capacitor C39 and the other end of the twenty-second resistor R69 are connected to the main control chip U1. In this embodiment, the analog acquisition port with switchable acquisition modes (0-10V / 4-20mA) designed based on TL074 plays an important role in industrial control systems. Its main function is to realize the acquisition and conversion of different types of analog signals. Through this acquisition port, the system can simultaneously support two common analog signal acquisition modes of 0-10V and 4-20mA. The 0-10V mode is suitable for collecting voltage-type analog signals, while the 4-20mA mode is suitable for collecting current-type analog signals. Such a design enables the system to adapt to the output of different types of sensors or signal sources, and can flexibly collect and process signals.Through the amplification, filtering and other functions provided by TL074, the collected analog signals can be processed as necessary to meet the system's requirements for signal accuracy and stability.

[0095] like Fig. 9As shown, the analog output interface is connected to the main control chip U1 for processing, converting and outputting analog signals. The analog output interface circuit includes: a twenty-fourth resistor R209, a twenty-fifth resistor R208, a fourth operational amplifier U20C, a twenty-sixth resistor R213, a tenth capacitor C122, an eleventh capacitor C118, a twelfth capacitor C123, a twenty-seventh resistor R219, a twenty-sixth resistor R220, a twenty-ninth resistor R215, a thirtieth resistor R211, a thirty-first resistor R210, a fifth operational amplifier U20B, a thirty-second resistor R216, a thirteenth capacitor C124, a thirty-third resistor R217, a thirty-fourth resistor R212, a thirty-fifth resistor R218, a thirty-sixth resistor R204, a first triode tube Q5, the second connector J3, the fourteenth capacitor C121 and the fifth switch diode D13; the non-inverting input end of the fourth operational amplifier U20C is connected to the main control chip U1 through the twenty-fourth resistor R209 and the twenty-fifth resistor R208 in sequence, the inverting input end of the fourth operational amplifier U20C is connected to the twenty-seventh resistor R219, the twenty-sixth resistor R220, and one end of the twenty-ninth resistor R215, one end of the twenty-sixth resistor R213 is connected to the main control chip U1, and the other end is grounded; one end of the tenth capacitor C122 and one end of the eleventh capacitor C118 are both connected between the twenty-fourth resistor R209 and the twenty-fifth resistor R208, The other end of the tenth capacitor C122 is grounded; one end of the twelfth capacitor C123 is connected between the twenty-fourth resistor R209 and the in-phase input terminal of the fourth operational amplifier U20C, and the other end is grounded; the other ends of the twenty-seventh resistor R219 and the twenty-sixth resistor R220 are grounded; one end of the thirtieth resistor R211 is connected to the output terminal of the fourth operational amplifier U20C, and the other end is connected to the eleventh capacitor C118 and the other end of the twenty-ninth resistor R215; one end of the thirty-first resistor R210 is connected to the pin 1 of the second connector J3 and one end of the thirteenth capacitor C124, and then connected to the other end of the thirtieth resistor R211 and the eleventh capacitor C1 18; the non-inverting input terminal of the fifth operational amplifier U20B is connected to the other end of the thirty-first resistor R210; the inverting input terminal of the fifth operational amplifier U20B is connected to the thirty-second resistor R216 and one end of the thirty-third resistor R217; the output terminal of the fifth operational amplifier U20B is connected to the base of the first transistor Q5 through the thirty-fourth resistor R212; the other end of the thirty-second resistor R216 and the other end of the thirteenth capacitor C124 are grounded; the collector of the first transistor Q5 is connected to the +15V interface, and the emitter of the first transistor Q5 is connected to the other end of the thirty-third resistor R217 and one end of the thirty-fifth resistor R218;One end of the thirty-sixth resistor R204, the other end of the thirty-fifth resistor R218, and the pin 3 of the second connector J3 are connected, and the other end of the thirty-sixth resistor R204 is connected between the in-phase input end of the fifth operational amplifier U20B and the other end of the thirty-first resistor R210; the pin 2 of the second connector J3, one end of the fourteenth capacitor C121, the pin 3 of the fifth switch diode D13, and the external output interface are connected; the other end of the fourteenth capacitor C121 is grounded. In this embodiment, the analog output interface designed based on TL074 mainly processes, converts and outputs analog signals. As a four-way operational amplifier, TL074 has the characteristics of high input impedance and low output impedance, and is suitable for amplifying and processing analog signals. Through this interface, the analog signal inside the system can be amplified, filtered, mixed, etc. to meet specific application requirements. At the same time, the analog output interface can output the processed analog signal to an external device or system, which is used to drive external devices such as motors, controllers, and displays to achieve control and regulation of external devices. In addition, it can also realize digital to analog data conversion, converting digital signals into analog signals for output. Through appropriate circuit design, the output of TL074 can be converted into the required voltage or current signal to meet the input requirements of external devices. ;

[0096] like Fig.10As shown, the buffer circuit is connected to the main control chip U1 for amplifying, buffering and transmitting input signals. In this embodiment, the buffer circuit designed based on 74AHCT367 plays an important role in the digital system. It is mainly used to amplify, buffer and transmit input signals to ensure the stability and reliability of the signal. When the current or voltage output by the signal source in the digital system is weak, the signal can be effectively amplified after being processed by the buffer circuit to meet the input requirements of the subsequent circuit or device. This signal amplification function helps to enhance the strength of the signal, thereby improving the transmission quality and stability of the signal. In addition to amplifying the signal, the buffer circuit can also provide a signal buffering function. In a digital system, due to factors such as resistance and capacitance between circuits, the signal may be attenuated or delayed. Through the action of the buffer circuit, the input signal can be effectively buffered and maintained, so that the output signal can maintain a high level stability, reduce signal distortion and jitter, thereby improving the performance and reliability of the system. In addition, the buffer circuit can also provide electrical isolation function. In a digital system, there may be interference or noise between different circuits, which may affect the transmission and reception of the signal. Through the buffer circuit, the input signal can be effectively isolated and protected to prevent interference signals from affecting the output signal, thereby improving the anti-interference ability and stability of the system. In addition, the buffer circuit can also convert between different logic levels. In a digital system, there may be different types of logic circuits, such as TTL and CMOS circuits. Through the buffer circuit, different types of logic levels can be converted to ensure compatibility and connection between different circuits, thereby improving the flexibility and scalability of the system.

[0097] like Fig.11As shown, the monitoring circuit is connected to the main control chip U1 and is used to monitor the power supply of the main control chip U1. The monitoring circuit includes: a thirty-seventh resistor R38, a thirty-eighth resistor R54, a fifteenth capacitor C31, a monitoring chip U8, a sixteenth capacitor C33, a thirty-ninth resistor R56, a seventeenth capacitor C34, a fortieth resistor R53, a forty-first resistor R55, an eighteenth capacitor C32, a nineteenth capacitor C30 and an inverter U14D; one end of the thirty-seventh resistor R38 is connected to a 3.3V voltage, and the other end of the thirty-seventh resistor R38 is grounded through the thirty-eighth resistor R54 and connected to pin 4 of the monitoring chip U8; one end of the fifteenth capacitor C31 is connected between pin 4 of the monitoring chip U8 and one end of the thirty-eighth resistor R54, and the fifteenth capacitor C31 is grounded; one end of the sixteenth capacitor C33 is connected to pin 3 of the monitoring chip U8, and grounded, the other end of the sixteenth capacitor C33 is connected to the 5V voltage and one end of the thirty-ninth resistor R56; the other end of the thirty-ninth resistor R56 is connected to the pin 7 of the monitoring chip U8, and then grounded through the seventeenth capacitor C34; the pin 8 of the monitoring chip U8 is connected to one end of the inverter U14D through the fortieth resistor R53; one end of the forty-first resistor R55 is connected to one end of the eighteenth capacitor C32, and then connected between the pin 8 of the monitoring chip U8 and the fortieth resistor R53, and the other end of the forty-first resistor R55 and the other end of the eighteenth capacitor C32 are grounded; one end of the nineteenth capacitor C30 is connected between the fortieth resistor R53 and one end of the inverter U14D, and the other end is grounded; the other end of the inverter U14D is connected to the main control chip U1. In this embodiment, the main function of the monitoring circuit designed based on MAX708 for protecting the main control chip U1 is to monitor the power supply of the main control chip U1, and to protect and handle power supply abnormalities. MAX708 can monitor whether the power supply voltage of the main control chip U1 is within the safe range, and generate a reset signal when a power supply abnormality is detected to prevent the main control chip U1 from being affected by power instability or abnormality, thereby improving the stability and reliability of the system. In addition, MAX708 can also provide power protection function to protect the main control chip U1 from damage caused by power overvoltage, overcurrent, overload, etc. It can control the power switch and cut off the power supply to prevent the main control chip U1 from being affected by power supply abnormalities and extend the service life of the main control chip U1. In addition, MAX708 can also generate a reset signal to restart or reset the main control chip U1. When the main control chip U1 fails or has an abnormality, it can automatically generate a reset signal to reset the main control chip U1 to the initial state and restore the normal operation of the system. Some models of MAX708 also have a temperature monitoring function, which can monitor whether the operating temperature of the main control chip U1 is within the safe range. When a temperature abnormality is detected, an alarm signal can be generated or measures can be taken to protect the main control chip U1 from overheating damage.

[0098] Above, refer to Figures 1 to 11 This paper describes a professional inverter control circuit for water pump driving according to the embodiment of the utility model, which combines the professional inverter control circuit with multiple functional modules, and realizes precise control and optimized regulation of the water pump drive system through a 32-bit DSP main control chip. Its advantages include improved performance, reduced costs, improved cost performance, convenient production, clean and environmentally friendly, etc., which make the system have higher stability, reliability and economy, and is suitable for various industrial application scenarios, bringing users a more convenient, reliable and efficient use experience. The details are as follows:

[0099] 1. Performance improvement: Using professional 32-bit DSP as the main control chip, combined with a variety of functional modules, it realizes precise control and optimization of the water pump drive system, and improves the performance of the system. For example: through the design of analog output circuit and PWM drive circuit, it can realize precise control of the water pump motor, and improve the operation stability and response speed of the system.

[0100] 2. Cost reduction: Comprehensive design of multiple functional modules, such as optocoupler input interface, relay output interface, communication interface, etc., realizes linkage control and data communication of external devices, reduces the system's dependence on external additional devices, and reduces the system's cost and maintenance expenses.

[0101] 3. Improved cost performance: By comprehensively considering the design and integration of various functional modules, the functions of the water pump drive system have been comprehensively improved, which has significantly improved the cost performance of the system. Compared with the traditional drive system, this solution is not only more powerful, but also more cost-effective and more cost-effective.

[0102] 4. Convenient production: It uses a variety of common chips and components, such as TL074, LM339, MAX708, etc. These components are easy to purchase and assemble, which is conducive to the management and control of the production process and improves production efficiency.

[0103] 5. Clean and environmentally friendly: The use of digital signal processing and communication interfaces reduces dependence on traditional analog signal lines, reduces electromagnetic interference and the complexity of cable wiring, is conducive to improving the reliability and stability of the system, and is also in line with the development trend of clean and environmental protection.

[0104] It should be noted that, in this specification, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprises..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0105] Although the content of the utility model has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the utility model. After reading the above content, various modifications and substitutions of the utility model will be obvious to those skilled in the art. Therefore, the protection scope of the utility model should be limited by the attached claims.

Claims

1. A professional inverter control circuit for water pump driving, characterized in that: Include: Main control chip, used for real-time control and signal processing; A switch input interface circuit, which is connected to the main control chip and is used for isolating and transmitting input signals; A relay output interface circuit, the relay output interface circuit is connected to the main control chip and is used to control external electrical equipment; RS485 communication interface circuit, the RS485 communication interface circuit is connected to the main control chip for communication; CAN communication interface circuit, the CAN communication interface circuit is connected to the main control chip and is used for data transmission; A frequency converter PWM drive circuit, which is connected to the main control chip and is used to generate a PWM signal to adjust and control the voltage and frequency output by an external frequency converter; A PTC signal acquisition interface circuit, which is connected to the main control chip and is used to process and convert analog signals from an external PTC sensor; An analog quantity acquisition interface circuit, which is connected to the main control chip and is used for collecting and converting analog quantities; An analog output interface circuit, the analog output interface is connected to the main control chip and is used to process, convert and output analog signals; A buffer circuit, the buffer circuit is connected to the main control chip and is used to amplify, buffer and transmit input signals; A monitoring circuit is connected to the main control chip and is used to monitor the power supply of the main control chip.

2. The professional inverter control circuit for water pump driving as claimed in claim 1, characterized in that: The PTC signal acquisition interface circuit comprises: a first operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first switch diode, a sixth resistor, a first capacitor, a seventh resistor, a second operational amplifier, an eighth resistor, a ninth resistor, a tenth resistor, a second switch diode, an eleventh resistor, a twelfth resistor, a third capacitor and a second capacitor; The non-inverting input terminal of the first operational amplifier is connected to the external PTCP interface through the first resistor, and the inverting input terminal of the first operational amplifier is connected to the external PTCN interface through the second resistor and the third resistor; One end of the fourth resistor and the fifth resistor is connected to the +4V-P interface, the other end of the fourth resistor is connected between the first resistor and the external PTCP interface, and the other end of the fifth resistor is connected between the second resistor and the third resistor; The pin 3 of the first switch diode, the output end of the first operational amplifier, one end of the sixth resistor and one end of the seventh resistor are connected; The other end of the sixth resistor is connected to the inverting input end of the first operational amplifier, and the first capacitor is connected in parallel with the sixth resistor; The non-inverting input terminal of the second operational amplifier is connected to the other end of the seventh resistor, the output terminal of the second operational amplifier is connected to one end of the ninth resistor, and the inverting input terminal of the second operational amplifier is connected to the other end of the ninth resistor and then connected to one end of the tenth resistor; The pin 3 of the second switch diode, the other end of the tenth resistor, the eleventh resistor and one end of the second capacitor are connected; One end of the twelfth resistor is connected to the other end of the tenth resistor, and the other end of the twelfth resistor, the other end of the second capacitor, and one end of the third capacitor are grounded; The eleventh resistor is connected to the other end of the third capacitor and then connected to the main control chip.

3. The professional inverter control circuit for water pump driving as claimed in claim 2, characterized in that: The PTC signal acquisition interface circuit further comprises: a thirteenth resistor and a fourth capacitor; One end of the thirteenth resistor and the fourth capacitor is grounded, the other end of the thirteenth resistor and the fourth capacitor is connected to the non-inverting input terminal of the first operational amplifier, and the other end of the thirteenth resistor is located between the non-inverting input terminal of the first operational amplifier and the other end of the fourth capacitor.

4. The professional inverter control circuit for water pump driving as claimed in claim 1, characterized in that: The analog quantity acquisition interface circuit comprises: a first connector, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a third operational amplifier, a third switch diode, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a fifth capacitor, a sixth capacitor, a seventh capacitor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, a fourth switch diode, an eighth capacitor and a ninth capacitor; The first connector is connected to the non-inverting input terminal of the third operational amplifier through the fourteenth resistor, the fifteenth resistor, and the sixteenth resistor in sequence; The seventeenth resistor, the eighteenth resistor, and the nineteenth resistor are connected in series to ground in sequence, and one end of the seventeenth resistor is connected between the fourteenth resistor and the fifteenth resistor; One end of the fifth capacitor is connected between the seventeenth resistor and the fifteenth resistor, and the other end is grounded; One end of the sixth capacitor and the pin 3 of the third switch diode are connected between the fifteenth resistor and the sixteenth resistor, and the other end of the sixth capacitor is grounded; One end of the seventh capacitor is connected between the non-inverting input terminal of the third operational amplifier and the sixteenth resistor, and the other end is grounded; The output terminal of the third operational amplifier is connected to the inverting input terminal of the third operational amplifier and one end of the twentieth resistor; The 20th resistor, the 21st resistor, and the 22nd resistor are connected in series in sequence; One end of the twenty-third resistor is connected between one end of the twenty-first resistor and one end of the twenty-second resistor; Pin 3 of the fourth switch diode and one end of the eighth capacitor are both connected between one end of the twenty-third resistor and one end of the twenty-second resistor; The other end of the eighth capacitor, the other end of the twenty-third resistor, and one end of the ninth capacitor are grounded; The other end of the ninth capacitor and the other end of the twenty-second resistor are connected to the main control chip.

5. The professional inverter control circuit for water pump driving as claimed in claim 1, characterized in that: The analog output interface circuit comprises: a twenty-fourth resistor, a twenty-fifth resistor, a fourth operational amplifier, a twenty-sixth resistor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, a twenty-seventh resistor, a twenty-eighth resistor, a twenty-ninth resistor, a thirtieth resistor, a thirty-first resistor, a fifth operational amplifier, a thirty-second resistor, a thirteenth capacitor, a thirty-third resistor, a thirty-fourth resistor, a thirty-fifth resistor, a thirty-sixth resistor, a first triode, a second connector, a fourteenth capacitor and a fifth switch diode; The non-inverting input terminal of the fourth operational amplifier is connected to the main control chip through the twenty-fourth resistor and the twenty-fifth resistor in sequence, and the inverting input terminal of the fourth operational amplifier is connected to one end of the twenty-seventh resistor, the twenty-eighth resistor, and the twenty-ninth resistor; One end of the twenty-sixth resistor is connected to the main control chip, and the other end is grounded; One end of the tenth capacitor and one end of the eleventh capacitor are both connected between the twenty-fourth resistor and the twenty-fifth resistor, and the other end of the tenth capacitor is grounded; One end of the twelfth capacitor is connected between the twenty-fourth resistor and the non-inverting input terminal of the fourth operational amplifier, and the other end is grounded; The other ends of the 27th resistor and the 28th resistor are grounded; One end of the 30th resistor is connected to the output end of the fourth operational amplifier, and the other end is connected to the other end of the 11th capacitor and the 29th resistor; One end of the thirty-first resistor is connected to the pin 1 of the second connector and one end of the thirteenth capacitor, and then connected between the other end of the thirtieth resistor and the other end of the eleventh capacitor; The non-inverting input terminal of the fifth operational amplifier is connected to the other end of the thirty-first resistor, the inverting input terminal of the fifth operational amplifier is connected to one end of the thirty-second resistor and the thirty-third resistor, and the output terminal of the fifth operational amplifier is connected to the base of the first transistor through the thirty-fourth resistor; The other end of the thirty-second resistor and the other end of the thirteenth capacitor are grounded; The collector of the first transistor is connected to a +15V interface, and the emitter of the first transistor is connected to the other end of the thirty-third resistor and one end of the thirty-fifth resistor; One end of the thirty-sixth resistor, the other end of the thirty-fifth resistor, and the pin 3 of the second connector are connected, and the other end of the thirty-sixth resistor is connected between the non-inverting input end of the fifth operational amplifier and the other end of the thirty-first resistor; The pin 2 of the second connector, one end of the fourteenth capacitor, the pin 3 of the fifth switch diode and the external output interface are connected; The other end of the fourteenth capacitor is grounded.

6. The professional inverter control circuit for water pump driving as claimed in claim 1, characterized in that: The monitoring circuit comprises: a thirty-seventh resistor, a thirty-eighth resistor, a fifteenth capacitor, a monitoring chip, a sixteenth capacitor, a thirty-ninth resistor, a seventeenth capacitor, a fortieth resistor, a forty-first resistor, an eighteenth capacitor, a nineteenth capacitor and an inverter; One end of the thirty-seventh resistor is connected to the 3.3V voltage, and the other end of the thirty-seventh resistor is grounded through the thirty-eighth resistor and connected to the pin 4 of the monitoring chip; One end of the fifteenth capacitor is connected between the pin 4 of the monitoring chip and one end of the thirty-eighth resistor, and the fifteenth capacitor is grounded; One end of the sixteenth capacitor is connected to pin 3 of the monitoring chip and is grounded, and the other end of the sixteenth capacitor is connected to a 5V voltage and one end of the thirty-ninth resistor; The other end of the thirty-ninth resistor is connected to the pin 7 of the monitoring chip and then grounded through the seventeenth capacitor; The pin 8 of the monitoring chip is connected to one end of the inverter through the 40th resistor; After one end of the forty-first resistor is connected to one end of the eighteenth capacitor, it is connected between the pin 8 of the monitoring chip and the fortieth resistor, and the other end of the forty-first resistor and the other end of the eighteenth capacitor are grounded; One end of the nineteenth capacitor is connected between the fortieth resistor and one end of the inverter, and the other end is grounded; The other end of the inverter is connected to the main control chip.

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