Electronic water pump control system and method based on adjustable carrier frequency pwm wave

Abstract

The application discloses an electronic water pump control system and method based on an adjustable carrier frequency PWM wave, and the system comprises a state detection module, a micro control unit, a carrier frequency adjusting module, a PWM signal generating module, a driving module and a feedback adjusting module; the method comprises the following steps: S1, system initialization; S2, running parameter collection; S3, running state evaluation; S4, optimal carrier frequency calculation; S5, carrier frequency adjustment; S6, PWM driving operation; S7, closed-loop feedback adjustment; and S8, cyclic execution. The application can accurately adjust the carrier frequency according to the real-time running state of the electronic water pump, effectively improves the running efficiency of the electronic water pump under different working conditions, reduces the switching loss and running noise, has strong adaptability, can adapt to electronic water pumps of different types and different specifications by adjusting control algorithm parameters, and has a wide application range.

Description

Technical Field

[0001] This invention belongs to the field of electronic water pump control technology, specifically relating to an electronic water pump control system and method based on adjustable carrier frequency PWM waves. Background Technology

[0002] Electric water pumps, with their advantages of small size, light weight, high efficiency, and high control precision, are widely used in various fields such as automotive cooling systems, industrial circulation systems, and residential heating systems. PWM (Pulse Width Modulation) technology, as one of the core technologies for electric water pump control, controls the motor speed of the electric water pump by adjusting the duty cycle of the PWM wave, thereby regulating the pump's flow rate and pressure. However, traditional PWM control methods typically use a fixed carrier frequency. In practical applications, the operating conditions of electric water pumps are complex and varied, and a fixed carrier frequency PWM wave is difficult to adapt to the needs of different operating conditions. When the electric water pump is operating under low load, a higher carrier frequency leads to increased switching losses, reduced system efficiency, and generates significant electromagnetic interference and operating noise; when the electric water pump is operating under high load, a lower carrier frequency leads to increased motor speed pulsation, affecting control precision and system stability. Existing technologies have attempted to adjust the carrier frequency of the PWM wave, but most are based on empirical values ​​or simple segmented adjustment strategies, lacking in-depth analysis of the quantitative relationship between the carrier frequency and the operating parameters of the electric water pump, resulting in insufficient adjustment precision and adaptability.

[0003] Therefore, there is an urgent need for a control system and method that can dynamically and accurately adjust the PWM wave carrier frequency according to the real-time operating status of the electronic water pump, in order to solve the problems of low efficiency, high noise, and poor stability in the existing technology. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an electronic water pump control system based on an adjustable carrier frequency PWM wave, which can accurately adjust the carrier frequency according to the real-time operating status of the electronic water pump, effectively improving the operating efficiency of the electronic water pump under different operating conditions and reducing switching losses and operating noise.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: an electronic water pump control system based on an adjustable carrier frequency PWM wave, comprising: The status detection module is used to collect the operating parameters of the electronic water pump and send them to the microcontroller unit. The operating parameters include at least stator current, stator voltage, motor speed and housing temperature. The microcontroller unit, connected to the status detection module, is used to receive and process the operating parameter signals sent by the status detection module, and generate carrier frequency adjustment commands and PWM parameter commands. The carrier frequency adjustment module, connected to the microcontroller unit, is used to adjust the carrier frequency of the PWM wave to the optimal carrier frequency according to the carrier frequency adjustment command sent by the microcontroller unit. ; The PWM signal generation module is connected to both the microcontroller unit and the carrier frequency adjustment module. It generates the PWM signal based on the PWM parameter commands sent by the microcontroller unit and the optimal carrier frequency output by the carrier frequency adjustment module. This generates the corresponding PWM signal; The drive module, connected to the PWM signal generation module, is used to amplify the power of the PWM signal and drive the electronic water pump to operate; The feedback regulation module is connected to the electronic water pump and the microcontroller unit respectively. It is used to collect the output flow rate Q and output pressure P of the electronic water pump and send them to the microcontroller unit to support closed-loop regulation.

[0006] The aforementioned electronic water pump control system based on adjustable carrier frequency PWM waves is characterized in that: the state detection module includes: A current sensor is used to collect the stator current of the electric water pump motor and send it to the microcontroller unit; A voltage sensor is used to collect the stator voltage of the electronic water pump motor and send it to the microcontroller unit; A speed sensor is used to collect the speed of the electric water pump motor and send it to the microcontroller unit; A temperature sensor is used to collect the housing temperature of the electronic water pump and send it to the microcontroller unit.

[0007] The above-mentioned electronic water pump control system based on adjustable carrier frequency PWM wave is characterized in that: the drive module includes a power switch, a drive circuit and a protection circuit; the power switch is a MOSFET or an IGBT, the drive circuit is used to drive the power switch to turn on and off, and the protection circuit includes at least an overcurrent protection circuit, an overvoltage protection circuit and an overheat protection circuit.

[0008] The above-mentioned electronic water pump control system based on adjustable carrier frequency PWM wave is characterized by: further including a communication module, which is connected to the microcontroller unit and used to realize data interaction between the control system and external devices; the communication module includes a CAN bus communication module, an RS485 communication module or an Ethernet communication module.

[0009] This invention also provides an electronic water pump control method based on an adjustable carrier frequency PWM wave using the above-mentioned control system. This method improves the operating efficiency of the electronic water pump, reduces noise and energy consumption, and enhances the stability and adaptability of the system by dynamically adjusting the carrier frequency of the PWM wave. The method includes the following steps: Step S1, System Initialization: The microcontroller sets the initial duty cycle of the PWM wave, the initial carrier frequency, the operating parameter thresholds, and the control algorithm parameters; Step S2, Operation Parameter Acquisition: The status detection module acquires the operating parameters of the electronic water pump in real time, including at least stator current, stator voltage, motor speed and housing temperature, and sends them to the microcontroller unit; Step S3, Operational Status Assessment: After preprocessing the operating parameters, the microcontroller unit assesses the current operational status of the electronic water pump; Step S4: Optimal carrier frequency calculation: Based on the evaluated operating status, the microcontroller calculates the optimal carrier frequency using a preset control algorithm. ; Step S5, Carrier Frequency Adjustment: The microcontroller sends a command to the carrier frequency adjustment module to adjust the PWM wave carrier frequency to... ; Step S6, PWM drive operation: The PWM signal generation module generates a PWM signal, which is amplified by the drive module to drive the electronic water pump to run; Step S7, Closed-loop feedback regulation: The feedback regulation module collects the output flow rate Q and output pressure P of the electronic water pump and sends them to the microcontroller unit. The microcontroller unit calculates the flow deviation ΔQ and pressure deviation ΔP, and corrects the PWM parameters and carrier frequency through the feedback control algorithm to achieve closed-loop control. Step S8, Repeat steps S2 to S7 to maintain the continuous and stable operation of the electronic water pump.

[0010] In the above-described electronic water pump control method based on adjustable carrier frequency PWM waves, the microcontroller preprocesses the operating parameters in step S3 using a moving average filtering method, and the calculation formula is as follows: ; in, Let N be the output value of the k-th filter, and N be the length of the sliding window. This represents the raw data collected in the i-th iteration.

[0011] The above-mentioned electronic water pump control method based on adjustable carrier frequency PWM wave includes a preset control algorithm in step S4, which includes a load calculation algorithm and an optimal carrier frequency solution algorithm. First, the load torque is calculated using the load calculation algorithm, and then the optimal carrier frequency is calculated based on the load torque using the optimal carrier frequency solution algorithm. .

[0012] The above-mentioned electronic water pump control method based on adjustable carrier frequency PWM wave calculates the load torque using the load calculation algorithm as follows: Load calculation sub-algorithm calculates load torque The formula is: ; in, For the output power of the electronic water pump, The mechanical angular velocity of the water pump motor; The calculation formula is: ; in, To convey liquid density, It is the acceleration due to gravity. To output flow, For Yang Cheng, For overall efficiency; The calculation formula is: ; in, This refers to the motor speed; The optimal carrier frequency is calculated based on the load torque using an optimal carrier frequency solution algorithm. The calculation formula used is: ; Where a, b, and c are control coefficients calibrated using experimental calibration methods; or a, b, and c are control coefficients calculated using a fuzzy control algorithm, where the fuzzy control algorithm uses... and For fuzzy input, The control coefficients a, b, and c are calculated through fuzzification, reasoning, and defuzzification.

[0013] In the above-mentioned electronic water pump control method based on adjustable carrier frequency PWM wave, the feedback control algorithm in step S7 is a PID control algorithm, and the specific method is as follows: Duty cycle correction The calculation formula is: ; in, , , These are the flow deviations. The proportional, integral, and differential coefficients, , , Pressure deviation The proportional, integral, and differential coefficients, For time; Corrected duty cycle ,in, To correct the duty cycle before; Carrier frequency correction The calculation formula is: ; in, , , These are the flow deviations. The proportional, integral, and differential coefficients, , , Pressure deviation The proportional, integral, and differential coefficients; Corrected carrier frequency ,in, The optimal carrier frequency is calculated in step S4.

[0014] The aforementioned electronic water pump control method based on adjustable carrier frequency PWM waves also includes fault diagnosis and protection steps during cyclic execution: the status detection module collects the operating parameters of the electronic water pump in real time, including at least stator current, stator voltage, motor speed and housing temperature, and sends them to the microcontroller unit; the microcontroller unit monitors the operating parameters, and when the parameters exceed the preset threshold, it determines a fault and triggers protection; the faults include overcurrent faults, overvoltage faults, overheating faults and stall faults; During an overcurrent fault, the stator current... The microcontroller unit controls the drive module to power off and sends an alarm signal; among which, This is the preset stator current threshold. During an overvoltage fault, the stator voltage The microcontroller reduces the carrier frequency and PWM duty cycle; if this fails to recover, a power-off alarm is triggered. This is the preset stator voltage threshold. During an overheating fault, the casing temperature The microcontroller reduces the water pump motor speed, and if the temperature continues to rise, it will trigger a power-off alarm; among other things, This is the preset shell temperature threshold; During a stall fault, the motor speed =0 and stator current The microcontroller unit controls the drive module to power off and sends an alarm signal; among which, This is the threshold value for the stall current of the motor.

[0015] Compared with existing technologies, this invention has the following advantages: By setting up a carrier frequency adjustment module and a feedback adjustment module, this invention achieves dynamic adjustment and closed-loop control of the PWM wave carrier frequency. It can accurately adjust the carrier frequency according to the real-time operating status of the electronic water pump, effectively improving the operating efficiency of the electronic water pump under different operating conditions and reducing switching losses and operating noise. Through multiple formulas, the calculation of the electronic water pump's operating parameters, load evaluation, optimal carrier frequency solution, and feedback adjustment process are quantitatively analyzed, making the control process more precise and controllable, providing a clear theoretical basis for system design, implementation, and optimization. The status detection module can comprehensively collect the operating parameters of the electronic water pump, including current, voltage, speed, temperature, flow rate, and pressure. Combined with fault diagnosis and protection procedures, it can promptly detect and handle various faults of the electronic water pump, enhancing the stability and reliability of the system. The control method has strong adaptability and can be adapted to different types and specifications of electronic water pumps by adjusting the control algorithm parameters, making it widely applicable.

[0016] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 This is a structural block diagram of the electronic water pump control system based on adjustable carrier frequency PWM wave of the present invention; Figure 2 This is a flowchart of the electronic water pump control method based on adjustable carrier frequency PWM wave of the present invention.

[0018] Explanation of reference numerals in the attached figures: 1—Status detection module; 2—Microcontroller unit; 3—Carrier frequency adjustment module; 4—PWM signal generation module; 5—Drive module; 6—Feedback adjustment module; 7—Electronic water pump. Detailed Implementation

[0019] Example 1 like Figure 1 As shown, the electronic water pump control system based on adjustable carrier frequency PWM wave in this embodiment includes: The status detection module 1 is used to collect the operating parameters of the electronic water pump 7 and send them to the microcontroller unit 2. The operating parameters include at least the stator current, stator voltage, motor speed and housing temperature. In this embodiment, the state detection module 1 includes: A current sensor is used to collect the stator current of the electric water pump 7 motor and send it to the microcontroller unit 2; A voltage sensor is used to collect the stator voltage of the electric water pump 7 motor and send it to the microcontroller unit 2; A speed sensor is used to collect the speed of the electric water pump 7 motor and send it to the microcontroller unit 2; A temperature sensor is used to collect the housing temperature of the electronic water pump 7 and send it to the microcontroller unit 2.

[0020] In specific implementation, the current sensor used is ACS712-05B, with a measurement range of -5A to +5A and an accuracy of 0.01A; the voltage sensor used is LV28-P, with a measurement range of 0-30V and an accuracy of 0.01V; the speed sensor used is a Hall effect speed sensor, model A3144, which measures the speed by detecting the signal of the magnet on the motor rotor, with a measurement range of 0-3000rpm and an accuracy of 1rpm; the temperature sensor used is DS18B20, with a measurement range of -55℃ to +125℃ and an accuracy of 0.1℃.

[0021] The microcontroller unit 2, connected to the status detection module 1, serves as the core control component. It is used to receive and process the operating parameter signals sent by the status detection module 1, and to generate carrier frequency adjustment commands and PWM parameter commands. In practice, the microcontroller 2 uses an STM32F4 series microcontroller, which features high performance and low power consumption, and has multiple built-in timers and ADC interfaces, which can meet the system's control and data acquisition requirements. The carrier frequency adjustment module 3, connected to the microcontroller unit 2, is used to adjust the carrier frequency of the PWM wave to the optimal carrier frequency according to the carrier frequency adjustment command sent by the microcontroller unit 2. ; In specific implementation, the carrier frequency adjustment module 3 is implemented using a programmable logic device (CPLD). Through digital control commands sent by the microcontroller unit, the output frequency of the internal clock circuit is adjusted, thereby realizing the adjustment of the PWM wave carrier frequency. The carrier frequency adjustment range is 1kHz-20kHz, and the adjustment accuracy is 10Hz. The PWM signal generation module 4 is connected to both the microcontroller unit 2 and the carrier frequency adjustment module 3, and is used to generate the PWM signal based on the PWM parameter commands sent by the microcontroller unit 2 and the optimal carrier frequency output by the carrier frequency adjustment module 3. This generates the corresponding PWM signal; that is, when generating the PWM signal, the PWM wave carrier frequency is adjusted to the optimal carrier frequency. ; In practice, the duty cycle adjustment range of the PWM signal is 0-100%, and the adjustment accuracy is 0.1%. The drive module 5 is connected to the PWM signal generation module 4 and is used to amplify the power of the PWM signal to drive the electronic water pump 7 to run. In this embodiment, the driving module 5 includes a power switch, a driving circuit, and a protection circuit; the power switch is a MOSFET or an IGBT, the driving circuit is used to drive the power switch to turn on and off, and the protection circuit includes at least an overcurrent protection circuit, an overvoltage protection circuit, and an overheat protection circuit.

[0022] In practical implementation, the power switching transistor is an N-channel MOSFET, model IRF540N, with a rated current of 33A and a rated voltage of 100V, which can meet the driving requirements of the electronic water pump motor. The drive circuit uses a dedicated driver chip IR2104, which has the characteristics of high input impedance and low output impedance, and can effectively drive the MOSFET to turn on and off. Overcurrent protection uses a current sensor ACS712 to collect the current signal. When the current exceeds the preset threshold, a protection signal is output to the microcontroller unit through a comparator. Overvoltage protection uses a voltage sensor LV28-P to collect the voltage signal, combined with a Zener diode to achieve overvoltage clamping protection. Overheat protection uses a thermistor NTC to collect the temperature signal. When the temperature exceeds the preset threshold, the protection mechanism is triggered.

[0023] The feedback regulation module 6 is connected to the electronic water pump 7 and the microcontroller unit 2 respectively. It is used to collect the output flow rate Q and output pressure P of the electronic water pump 7 and send them to the microcontroller unit 2 to support closed-loop regulation.

[0024] In practice, the electronic water pump 7 is connected to the drive module 5 to realize liquid transportation; the electronic water pump 7 is a brushless DC electronic water pump with a rated voltage of 12V, a rated power of 50W, a rated flow rate of 10L / min, and a rated head of 5m.

[0025] In practical implementation, the feedback regulation module includes a flow sensor and a pressure sensor. The flow sensor is a turbine flow sensor, model LWGY-15, with a measurement range of 0.6-6 m³ / h and an accuracy of 0.01 m³ / h. The pressure sensor is a diffused silicon pressure sensor, model MPX5010DP, with a measurement range of 0-10 kPa and an accuracy of 0.1 kPa. The feedback regulation module converts the collected flow and pressure signals into electrical signals and sends them to the ADC interface of the microcontroller unit.

[0026] In this embodiment, the control system also includes a communication module, which is connected to the microcontroller unit 2 and is used to realize data interaction between the control system and external devices; the communication module includes a CAN bus communication module, an RS485 communication module or an Ethernet communication module.

[0027] In practical implementation, the communication module adopts the CAN bus communication module and selects the TJA1050CAN transceiver, which can realize data interaction between the system and external ECU or monitoring equipment, with a transmission rate of up to 1Mbps and a transmission distance of up to 10km.

[0028] Example 2 like Figure 2 As shown, the electronic water pump control method based on adjustable carrier frequency PWM wave in this embodiment includes the following steps: Step S1, System Initialization: The microcontroller unit 2 sets the initial duty cycle of the PWM wave, the initial carrier frequency, the operating parameter thresholds, and the control algorithm parameters; In practice, the initial duty cycle of the PWM wave is set. =50%, initial carrier frequency =10kHz, operating parameter thresholds include maximum stator current =10A, maximum stator voltage =15V, maximum case temperature =85℃, locked rotor current threshold =8A, and simultaneously set the PID control algorithm parameters. in, , , , , , , , , , , , The sliding window length N=10 for the moving average filtering method.

[0029] Step S2, Operation Parameter Acquisition: The status detection module 1 acquires the operation parameters of the electronic water pump 7 in real time, including at least the stator current, stator voltage, motor speed and housing temperature, and sends them to the microcontroller unit 2; In practice, the status detection module 1 collects the stator current I, stator voltage U, motor speed n and shell temperature T of the electronic water pump body in real time according to a sampling period of 10ms, and sends the collected operating parameters to the microcontroller unit 2. Step S3, Operational Status Assessment: After preprocessing the operating parameters, the microcontroller unit 2 assesses the current operational status of the electronic water pump 7; In this embodiment, when the microcontroller unit 2 preprocesses the operating parameters in step S3, it uses the moving average filtering method, and the calculation formula is as follows: ; in, Let N be the output value of the k-th filter, and N be the length of the sliding window. This represents the raw data collected in the i-th iteration.

[0030] The moving average filtering method can remove high-frequency interference and random errors in the signal, effectively improving control accuracy.

[0031] In practice, the microcontroller unit 2 calculates the motor input power based on the pre-processed stator current I and stator voltage U, evaluates the motor operating efficiency in combination with the motor speed n, and judges the heating status of the equipment in combination with the housing temperature T, and comprehensively evaluates the current operating status of the electronic water pump.

[0032] Step S4: Optimal carrier frequency calculation: Based on the evaluated operating status, the microcontroller unit 2 calculates the optimal carrier frequency using a preset control algorithm. ; In this embodiment, the preset control algorithm in step S4 includes a load calculation algorithm and an optimal carrier frequency solution algorithm. First, the load torque is calculated using the load calculation algorithm, and then the optimal carrier frequency is calculated based on the load torque using the optimal carrier frequency solution algorithm. .

[0033] The specific method for calculating the load torque using the load calculation algorithm is as follows: Load calculation sub-algorithm calculates load torque The formula is: ; in, For the output power of the electronic water pump 7, The mechanical angular velocity of the water pump motor; The calculation formula is: ; in, To convey liquid density, It is the acceleration due to gravity. To output flow, For Yang Cheng, For overall efficiency; For example, if the liquid being transported is water, its density is... =1000kg / m³, gravitational acceleration g=9.8m / s², total efficiency of the electric water pump The value was measured to be 0.75 through experiments; In practice, the head H is calculated based on the system pipeline characteristic curve and the current flow rate Q. The calculation can be performed using existing technologies and will not be elaborated further. The calculation formula is: ; in, This refers to the motor speed; The optimal carrier frequency is calculated based on the load torque using an optimal carrier frequency solution algorithm. The calculation formula used is: ; Where a, b, and c are control coefficients calibrated using experimental calibration methods; or a, b, and c are control coefficients calculated using a fuzzy control algorithm, where the fuzzy control algorithm uses... and For fuzzy input, The control coefficients a, b, and c are calculated through fuzzification, reasoning, and defuzzification.

[0034] When calibrating the control coefficients a, b, and c using experimental calibration methods, the operating efficiency and noise level of the electronic water pump were tested under different load torques and speeds. The carrier frequency with the highest efficiency and lowest noise was selected as the optimal value, and a=2.5, b=0.003, and c=1.2 were obtained through linear fitting. When the control coefficients a, b, and c are calculated using the fuzzy control algorithm, the fuzzy subset of the input quantities of the fuzzy control algorithm is {small, medium, large}, and the fuzzy subset of the output quantities is {low, medium, high}.

[0035] Step S5, Carrier Frequency Adjustment: The microcontroller unit 2 sends a command to the carrier frequency adjustment module 3 to adjust the PWM wave carrier frequency to... ; In practice, the microcontroller unit 2 sends an 8-bit digital control command to the carrier frequency adjustment module 3. The carrier frequency adjustment module 3 adjusts the parameters of its internal RC oscillation circuit according to the command, thereby adjusting the PWM wave carrier frequency to... ; Step S6, PWM drive operation: The PWM signal generation module 4 generates a PWM signal, which is amplified by the drive module 5 and then drives the electronic water pump 7 to run; Step S7, Closed-loop feedback regulation: The feedback regulation module 6 collects the output flow rate Q and output pressure P of the electronic water pump 7 and sends them to the microcontroller unit 2. The microcontroller unit 2 calculates the flow deviation ΔQ and pressure deviation ΔP, and corrects the PWM parameters and carrier frequency through the feedback control algorithm to achieve closed-loop control. In this embodiment, the feedback control algorithm in step S7 is a PID control algorithm, and the specific method is as follows: Duty cycle correction The calculation formula is: ; in, , , These are the flow deviations. The proportional, integral, and differential coefficients, , , Pressure deviation The proportional, integral, and differential coefficients, For time; Corrected duty cycle ,in, To correct the duty cycle before; Carrier frequency correction The calculation formula is: ; in, , , These are the flow deviations. The proportional, integral, and differential coefficients, , , Pressure deviation The proportional, integral, and differential coefficients; Corrected carrier frequency ,in, The optimal carrier frequency is calculated in step S4.

[0036] Step S8, Cyclic execution: Repeat steps S2 to S7 to maintain the continuous and stable operation of the electronic water pump 7.

[0037] In this embodiment, the cyclic execution process also includes a fault diagnosis and protection step: the status detection module 1 collects the operating parameters of the electronic water pump 7 in real time, including at least the stator current, stator voltage, motor speed and housing temperature, and sends them to the microcontroller unit 2; the microcontroller unit 2 monitors the operating parameters, and when the parameters exceed the preset threshold, it determines the fault and triggers the protection; the faults include overcurrent faults, overvoltage faults, overheating faults and stall faults; During an overcurrent fault, the stator current... The microcontroller unit 2 controls the drive module 5 to power off and sends an alarm signal; among which, This is the preset stator current threshold. During an overvoltage fault, the stator voltage The microcontroller unit 2 reduces the carrier frequency and PWM duty cycle; if it fails to recover, a power-off alarm is triggered. This is the preset stator voltage threshold. During an overheating fault, the casing temperature The microcontroller unit 2 reduces the water pump motor speed, and if the temperature continues to rise, it will shut off the power and trigger an alarm; among other things, This is the preset shell temperature threshold; During a stall fault, the motor speed =0 and stator current The microcontroller unit 2 controls the drive module 5 to power off and sends an alarm signal; among which, This is the threshold value for the stall current of the motor.

[0038] This invention achieves dynamic adjustment and closed-loop control of the PWM wave carrier frequency by setting up a carrier frequency adjustment module and a feedback adjustment module. It can accurately adjust the carrier frequency according to the real-time operating status of the electronic water pump, effectively improving the operating efficiency of the electronic water pump under different operating conditions and reducing switching losses and operating noise.

[0039] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. An electronic water pump control method based on adjustable carrier frequency PWM wave, wherein the control system adopted includes: The status detection module (1) is used to collect the operating parameters of the electronic water pump (7) and send them to the microcontroller unit (2). The operating parameters include at least the stator current, stator voltage, motor speed and housing temperature. The status detection module (1) includes: A current sensor is used to collect the stator current of the electric water pump (7) motor and send it to the microcontroller unit (2). A voltage sensor is used to collect the stator voltage of the electric water pump (7) motor and send it to the microcontroller unit (2). A speed sensor is used to collect the speed of the electric water pump (7) motor and send it to the microcontroller unit (2); A temperature sensor is used to collect the housing temperature of the electronic water pump (7) and send it to the microcontroller unit (2). The microcontroller unit (2) is connected to the status detection module (1) and is used to receive and process the operating parameter signals sent by the status detection module (1) and generate carrier frequency adjustment instructions and PWM parameter instructions. The carrier frequency adjustment module (3) is connected to the microcontroller unit (2) and is used to adjust the carrier frequency of the PWM wave to the optimal carrier frequency according to the carrier frequency adjustment command sent by the microcontroller unit (2). ; The PWM signal generation module (4) is connected to the microcontroller unit (2) and the carrier frequency adjustment module (3) respectively, and is used to generate the PWM signal according to the PWM parameter command sent by the microcontroller unit (2) and the optimal carrier frequency output by the carrier frequency adjustment module (3). This generates the corresponding PWM signal; The drive module (5) is connected to the PWM signal generation module (4) and is used to amplify the power of the PWM signal to drive the electronic water pump (7) to run. The feedback adjustment module (6) is connected to the electronic water pump (7) and the microcontroller (2) respectively. It is used to collect the output flow rate Q and output pressure P of the electronic water pump (7) and send them to the microcontroller (2). The microcontroller (2) calculates the flow deviation ΔQ and pressure deviation ΔP, and corrects the PWM parameters and carrier frequency through the feedback control algorithm to realize closed-loop control and support closed-loop adjustment. The method is characterized by comprising the following steps: Step S1, System initialization: The microcontroller (2) sets the initial duty cycle of the PWM wave, the initial carrier frequency, the operating parameter thresholds and the control algorithm parameters; Step S2, Operation Parameter Acquisition: The status detection module (1) collects the operation parameters of the electronic water pump (7) in real time, including at least the stator current, stator voltage, motor speed and housing temperature, and sends them to the microcontroller unit (2). Step S3, Operation Status Assessment: After preprocessing the operating parameters, the microcontroller unit (2) assesses the current operating status of the electronic water pump (7); Step S4, Optimal Carrier Frequency Calculation: The microcontroller unit (2) calculates the optimal carrier frequency based on the evaluated operating status using a preset control algorithm. ; Step S5, Carrier Frequency Adjustment: The microcontroller (2) sends a command to the carrier frequency adjustment module (3) to adjust the PWM wave carrier frequency to... ; Step S6, PWM drive operation: The PWM signal generation module (4) generates a PWM signal, which is amplified by the drive module (5) and drives the electronic water pump (7) to run; Step S7, Closed-loop feedback regulation: The feedback regulation module (6) collects the output flow rate Q and output pressure P of the electronic water pump (7) and sends them to the microcontroller (2). The microcontroller (2) calculates the flow deviation ΔQ and pressure deviation ΔP, and corrects the PWM parameters and carrier frequency through the feedback control algorithm to achieve closed-loop control. Step S8, Cyclic Execution: Repeat steps S2 to S7 to maintain the continuous and stable operation of the electronic water pump (7); The feedback control algorithm mentioned in step S7 is a PID control algorithm, and the specific method is as follows: Duty cycle correction The calculation formula is: ； in, , , These are the flow deviations. The proportional, integral, and differential coefficients, , , Pressure deviation The proportional, integral, and differential coefficients, For time; Corrected duty cycle ,in, To correct the duty cycle before; Carrier frequency correction The calculation formula is: ； in, , , These are the flow deviations. The proportional, integral, and differential coefficients, , , Pressure deviation The proportional, integral, and differential coefficients; Corrected carrier frequency ,in, The optimal carrier frequency is calculated in step S4.

2. The electronic water pump control method based on adjustable carrier frequency PWM wave according to claim 1, characterized in that: The drive module (5) includes a power switch, a drive circuit, and a protection circuit; the power switch is a MOSFET or an IGBT, the drive circuit is used to drive the power switch to turn on and off, and the protection circuit includes at least an overcurrent protection circuit, an overvoltage protection circuit, and an overheat protection circuit.

3. The electronic water pump control method based on adjustable carrier frequency PWM wave according to claim 1, characterized in that: It also includes a communication module, which is connected to the microcontroller (2) and is used to realize data interaction between the control system and external devices; the communication module includes a CAN bus communication module, an RS485 communication module or an Ethernet communication module.

4. The electronic water pump control method based on adjustable carrier frequency PWM wave according to claim 1, characterized in that: In step S3, the microcontroller unit (2) preprocesses the operating parameters using a moving average filtering method, and the calculation formula is as follows: ； in, Let N be the output value of the k-th filter, and N be the length of the sliding window. This represents the raw data collected in the i-th iteration.

5. The electronic water pump control method based on adjustable carrier frequency PWM wave according to claim 1, characterized in that: The preset control algorithm in step S4 includes a load calculation algorithm and an optimal carrier frequency solution algorithm. First, the load torque is calculated using the load calculation algorithm, and then the optimal carrier frequency is calculated based on the load torque using the optimal carrier frequency solution algorithm. .

6. The electronic water pump control method based on adjustable carrier frequency PWM wave according to claim 5, characterized in that: The specific method for calculating the load torque using the load calculation algorithm is as follows: The load calculation algorithm calculates the load torque. The formula is: ； in, For the output power of the electronic water pump (7), The mechanical angular velocity of the water pump motor; The The calculation formula is: ； in, To convey liquid density, It is the acceleration due to gravity. To output flow, For Yang Cheng, For overall efficiency; The The calculation formula is: ； in, This refers to the motor speed; The optimal carrier frequency is calculated based on the load torque using the optimal carrier frequency solution algorithm. The calculation formula used is: ； Where a, b, and c are control coefficients calibrated using experimental calibration methods; or a, b, and c are control coefficients calculated using a fuzzy control algorithm, where the fuzzy control algorithm uses... and For fuzzy input, The control coefficients a, b, and c are calculated through fuzzification, reasoning, and defuzzification.

7. The electronic water pump control method based on adjustable carrier frequency PWM wave according to claim 4, characterized in that: During the cyclic execution process, fault diagnosis and protection steps are also included: the status detection module (1) collects the operating parameters of the electronic water pump (7) in real time, including at least the stator current, stator voltage, motor speed and housing temperature, and sends them to the microcontroller (2); the microcontroller (2) monitors the operating parameters, and when the parameters exceed the preset threshold, it determines the fault and triggers protection; the faults include overcurrent faults, overvoltage faults, overheating faults and stall faults; During an overcurrent fault, the stator current... The microcontroller unit (2) controls the drive module (5) to power off and send an alarm signal; wherein, The preset stator current threshold; During an overvoltage fault, the stator voltage The microcontroller unit (2) reduces the carrier frequency and PWM duty cycle; if it fails to recover, a power-off alarm is triggered. This is the preset stator voltage threshold. During an overheating fault, the casing temperature The microcontroller unit (2) reduces the speed of the water pump motor, and if the temperature continues to rise, it will shut down and trigger an alarm; among which, This is the preset shell temperature threshold; During a stall fault, the motor speed =0 and stator current The microcontroller unit (2) controls the drive module (5) to power off and send an alarm signal; wherein, This is the threshold value for the stall current of the motor.

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