Intelligent control cooling fan driving method

Abstract

The invention discloses an intelligent control cooling fan driving method, relates to the technical field of intelligent cooling, and solves the problems that the working mode of a traditional fan is irrelevant to an electric control working state, the fan always runs at the maximum rotating speed after electric control is started, and electric energy is wasted. The cooling fan driving method comprises the steps that the controller conducts power sampling and dynamic calibration on the direct-current side and the alternating-current side of the inverter circuit respectively, and voltage and current are obtained; calculating corresponding power and a power loss value according to the corresponding voltage and current on the two sides, performing temperature compensation on the power loss value according to the junction temperature of the field effect transistor to obtain real-time power loss, and recording loss duration; according to the environment temperature, a loss power threshold value and a loss time threshold value are preset and compared with the real-time power loss and the loss duration time, and meanwhile the real-time power loss and the loss duration time are stored to the controller; and establishing a nonlinear mapping model of the PWM duty ratio and the voltage of the electric control high-power output port, and regulating and controlling the rotating speed of the fan in combination with a multi-stage speed regulation mechanism so as to complete the driving control of the fan.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent heat dissipation, and particularly to a method for intelligently controlling the driving of a cooling fan. Background Art

[0002] In a forklift motor control system, a large amount of heat is often generated when the motor controller is running. In order to timely and fully dissipate the heat, a cooling fan is generally added to the controller. With the development of modern power units such as inverters and converters towards high-density integration, the switching losses and conduction losses generated by the field effect transistors during their operation increase exponentially. The traditional constant-speed heat dissipation scheme has significant defects: under high-load conditions, if the loss continuously exceeds the loss threshold but the lowest fan speed is still maintained, it will cause the device junction temperature to exceed the safe range, leading to the risk of thermal failure; while excessive heat dissipation at low loads causes energy waste. Power loss refers to the power consumption lost during the conversion of energy input and output in a certain power grid circuit.

[0003] A motor controller, abbreviated as an electronic control, refers to a master control device that changes the wiring of the main circuit or control circuit and changes the resistance value in the circuit in a predetermined order to control the starting, speed regulation, braking, and reverse of the motor. It consists of a program counter, an instruction register, an instruction decoder, a timing generator, and an operation controller. It is the "decision-making body" that issues commands, that is, it completes the operation of coordinating and commanding the entire computer system.

[0004] PWM drive, that is, pulse width modulation, is a very effective technology for controlling analog circuits using the digital signals of a microcontroller. It is widely used in many fields from measurement, communication to power control and conversion.

[0005] The loss threshold and the loss duration standard are used as the basis for the microprocessor inside the motor controller to determine the PWM duty cycle mode for adjusting the voltage of the high-power output port. When the loss is higher than the threshold and the loss duration exceeds the standard, the PWM duty cycle increases, the voltage of the high-power output port increases, and the fan runs faster. On the contrary, when the loss is lower than the threshold and the loss duration exceeds the standard, the PWM duty cycle decreases, the voltage of the high-power output port decreases, and the fan runs slower.

[0006] Patent No. CN201810772109.5 discloses an intelligent heat dissipation system driven by a hydraulic motor and its heat dissipation method. The system includes a composite radiator, a radiator tail frame, and a hydraulic system. The composite radiator is inclined and installed on the horizontal plane at the top of the radiator tail frame. A number of air duct holes are provided on the radiator tail frame. The composite radiator includes heat dissipation fins, a hurricane hood, a fan, and a fan guard net covering the outside of the fan. The heat dissipation fins include intercooling fins, water-cooling fins, transmission oil cooling fins, and hydraulic oil cooling fins arranged in sequence from top to bottom. The hydraulic system includes a hydraulic motor, a hydraulic pump, a hydraulic oil tank, and a proportional solenoid valve. The above invention can not only meet the cooling requirements of the vehicle, but also achieve the purposes of energy conservation and noise reduction, and has the characteristics of high space utilization rate and good heat dissipation performance.

[0007] Patent No. CN202210706078.X discloses an intelligent heat dissipation control method for a vehicle electric drive system, which solves the technical problems of how to improve the performance of the heat dissipation system for electric vehicles, make the heat dissipation system quickly and accurately respond to the heat dissipation requirements of the electric drive system, reduce the energy consumption of the heat dissipation system for the whole vehicle, and improve the NVH level of the vehicle. The above invention integrates the heat dissipation control system with the vehicle control system. The vehicle controller collects various parameters of the electric drive system and environmental temperature and other information in real time. According to the collected information, the vehicle controller adjusts various parameters of the heat dissipation system in real time through corresponding control strategies, such as the start and stop of the electronic water pump and the electronic fan in the heat dissipation system, the water flow rate of the heat dissipation system, and the rotation speed of the electronic fan. The heat dissipation system can dynamically, quickly and accurately respond to the heat dissipation requirements of the electric drive system, thus avoiding damage to the components of the electric drive system due to overheating caused by untimely response of the heat dissipation system, or increasing the energy consumption and cost of the whole vehicle caused by excessive heat dissipation.

[0008] Although the above patents can use a heat dissipation fan to dissipate heat from the motor controller of an industrial vehicle; however, the working mode of the traditional fan has nothing to do with the working state of the electronic control. After the electronic control is turned on, the fan always runs at the maximum speed, resulting in waste of electric energy. Moreover, the field effect transistor is the main power component of the electronic control inverter circuit, causing conduction loss and switching loss, and these losses will be converted into heat, causing the electronic control to heat up. Summary of the Invention

[0009] The purpose of the present invention is to provide an intelligent control method for driving a heat dissipation fan, which can monitor the loss of the field effect transistor in the electronic control inverter circuit, adjust the voltage of the high-power output port of the electronic control according to the loss of the inverter circuit through the PWM duty cycle combined with a multi-stage speed regulation mechanism, control the fan speed, and set the electronic control loss threshold and duration standard; thereby controlling the heat dissipation fan to work with the optimal efficiency and achieving the purpose of efficient heat dissipation and energy saving.

[0010] The present invention uses the following technical solutions: An intelligent control method for driving a cooling fan, comprising the following steps; S1: The controller performs power sampling and dynamic calibration on the DC side and the AC side of the inverter circuit respectively to obtain the corresponding voltage and current; S2: Calculate the corresponding power and power loss value according to the corresponding voltage and current on both sides, and perform temperature compensation on the power loss value according to the junction temperature of the field effect transistor to obtain the real-time power loss, and record the loss duration; S3: According to the ambient temperature, preset the loss power threshold and loss time threshold of the field effect transistor of the electric control inverter circuit, compare them with the real-time power loss and loss duration, and store them in the controller at the same time; S4: Establish a non-linear mapping model between the PWM duty cycle and the voltage of the high-power output port of the electric control, and regulate the fan speed in combination with the multi-stage speed regulation mechanism, thereby completing the drive control of the fan.

[0011] Preferably, step S1 includes the following steps: S11: Use the temperature compensation algorithm according to the temperature sensor to correct the sampling offset error of the input power unit and the output power unit of the controller in real time; S12: The input power unit uses the synchronous sampling strategy to collect the voltage signal and current signal on the DC side of the inverter circuit in real time to obtain the input voltage signal and input current signal; S13: The output power unit uses the synchronous sampling strategy to collect the voltage signal and current signal on the AC side of the inverter circuit in real time to obtain the output voltage signal and output current signal; S14: Use the moving average filtering method and the moving window mean method in turn to denoise and smooth the input voltage signal, input current signal, output voltage signal and output current signal to obtain single-phase voltage, single-phase current, three-phase voltage and three-phase current.

[0012] Preferably, step S2 includes the following steps: S21: The arithmetic unit of the controller calculates the DC side power according to the single-phase voltage and single-phase current, in combination with the dead-time compensation coefficient; S22: The arithmetic unit converts the three-phase coordinate system on the AC side into a two-phase rotating coordinate system according to the three-phase voltage and three-phase current in combination with the Clarke-Park transformation algorithm, and calculates the AC side power; S23: The loss calculation unit of the controller calculates the power loss of the electric control inverter circuit according to the motor operation mode to obtain the power loss value; S24: Perform temperature compensation on the power loss value according to the junction temperature of the field effect transistor to obtain the real-time power loss: S25: Use the sliding time integration method to calculate the time of the power loss of the electric control inverter circuit to obtain the loss duration.

[0013] Preferably, S3 includes the following steps: S31: Calculate the loss of the field-effect transistor in the electric control inverter circuit based on the safe operating area curve of the field-effect transistor and in combination with the thermal resistance of the radiator to obtain the steady-state allowable loss; S32: Dynamically correct the steady-state allowable loss according to the ambient temperature to obtain the loss power threshold; S33: Use a sliding window to classify and count the occupancy time of the loss power threshold to obtain the loss time threshold; S34: The monitoring and display unit of the controller displays the loss power threshold and the loss time threshold, and at the same time makes a dual-mode comparison with the real-time power loss and the loss duration, and stores them in the storage unit of the controller.

[0014] Preferably, S3 includes the following steps: If the real-time power loss is higher than the loss power threshold and the loss duration is greater than or equal to the loss time threshold, then control the PWM duty cycle to increase and the voltage of the high-power output port of the electric control to increase; If the real-time power loss is lower than the loss power threshold and the loss duration is greater than or equal to the loss time threshold, then control the PWM duty cycle to decrease and the voltage of the high-power output port of the electric control to decrease; If the real-time power loss is equal to the loss power threshold, then set the upper and lower threshold bands of the loss time threshold and keep both the PWM duty cycle and the voltage of the high-power output port of the electric control unchanged; If the real-time power loss is not equal to the loss power threshold, or the loss duration is less than the loss time threshold, then keep both the PWM duty cycle and the voltage of the high-power output port of the electric control unchanged, and set a fast response window to suppress the transient spike loss of the voltage.

[0015] Preferably, S4 includes the following steps: S41: Establish a non-linear mapping model between the PWM duty cycle and the voltage of the high-power output port of the electric control according to the output characteristics of the field-effect transistor; S42: Generate a duty cycle-air volume mapping table according to the static pressure-air volume curve of the fan and in combination with the non-linear mapping model; S43: Use a Hall sensor to detect the actual speed of the fan and perform feedback regulation on the PWM duty cycle in combination with a proportional-derivative controller; S44: Regulate the fan speed according to the duty cycle-air volume mapping table and the ambient temperature in combination with a multi-stage speed regulation mechanism, and then complete the drive control of the fan.

[0016] Preferably, the working process of the multi-stage speed regulation mechanism is: A: Based on the ambient temperature and the junction temperature of the field effect transistor, combining the loss power threshold and the loss time threshold, establish a thermal inertia network model of the inverter circuit; B: Simulate and verify the thermal inertia network model with the static pressure - air volume curve to obtain the air volume - thermal inertia - time curve; C: According to the duty ratio - air volume mapping table, use fuzzy clustering analysis to divide the speed regulation range: In the steep change area where the air volume change rate is greater than or equal to the air volume threshold, set a dense grading with a duty ratio of every m% as one grade; In the gentle area where the air volume change rate is less than the air volume threshold, set a wide - interval grading with a duty ratio of every 2m% as one grade; D: Discretize the air volume - thermal inertia - time curve into a heat dissipation state - space equation, and predict the real - time power loss to generate a prediction result; E: According to the prediction result combined with the speed regulation range, pre - adjust the PWM duty ratio M τ - cycles in advance, and then complete the multi - stage speed regulation of the fan.

[0017] The present invention monitors the loss of the field effect transistor in the electronic control inverter circuit, adjusts the voltage of the high - power output port of the electronic control through the PWM duty ratio combined with the multi - stage speed regulation mechanism according to the loss of the inverter circuit, controls the fan speed, and sets the electronic control loss threshold and the duration standard; further controls the cooling fan to work with the optimal efficiency, and achieves the purpose of efficient heat dissipation and power saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the related art, the following will briefly introduce the drawings required for use in the description of the embodiments or the related art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to the provided drawings without creative efforts.

[0019] Figure 1 It is a principle block diagram of the cooling fan driving method; Figure 2 It is a control strategy block diagram of the cooling fan driving method; Figure 3 It is a control flow chart of the multi - stage speed regulation mechanism. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The following will describe the present invention in detail with reference to the drawings and embodiments: As Figures 1-3 shown, an intelligent control cooling fan driving method of the present invention includes the following steps: S1: The controller respectively performs power sampling and dynamic calibration on the DC side and the AC side of the inverter circuit to obtain the corresponding voltage and current; S2: Calculate the corresponding power and power loss value according to the voltages and currents on both sides, perform temperature compensation on the power loss value according to the junction temperature of the field-effect transistor to obtain the real-time power loss, and record the loss duration; S3: Preset the loss power threshold and loss time threshold of the field-effect transistor of the electric control inverter circuit according to the ambient temperature, compare them with the real-time power loss and loss duration, and store them in the controller at the same time; S4: Establish a non-linear mapping model between the PWM duty cycle and the voltage of the high-power output port of the electric control, and regulate the fan speed in combination with the multi-stage speed regulation mechanism, so as to complete the drive control of the fan.

[0021] In this embodiment, the voltage of the high-power output port of the electric control refers to the voltage value of the output port used to drive high-power loads (such as motors, frequency converters, etc.) in the power control system.

[0022] In the present invention, step S1 includes the following steps: S11: Use the temperature compensation algorithm according to the temperature sensor to correct the sampling offset error of the input power unit and the output power unit of the controller in real time; S12: The input power unit uses the synchronous sampling strategy to collect the voltage signal and current signal on the DC side of the inverter circuit in real time to obtain the input voltage signal and input current signal; S13: The output power unit uses the synchronous sampling strategy to collect the voltage signal and current signal on the AC side of the inverter circuit in real time to obtain the output voltage signal and output current signal; S14: Use the moving average filtering method and the moving window mean method to denoise and smooth the input voltage signal, input current signal, output voltage signal and output current signal in sequence to obtain the single-phase voltage , single-phase current , three-phase voltage and three-phase current .

[0023] In the present invention, step S2 includes the following steps: S21: The arithmetic unit of the controller calculates the DC side power according to the single-phase voltage and single-phase current, in combination with the dead-time compensation coefficient kd: ; S22: The arithmetic unit calculates the AC side power by converting the three-phase coordinate system on the AC side to a two-phase rotating coordinate system according to the three-phase voltage and three-phase current in combination with the Clarke-Park transformation algorithm: ; S23: The loss calculation unit of the controller calculates the power loss of the electric control inverter circuit according to the motor operation mode to obtain a power loss value. ; In this embodiment, when the motor operation mode is the electric mode, ; When the motor operation mode is the power generation mode, ; S24: Perform temperature compensation on the power loss value according to the junction temperature of the field effect transistor to obtain the real-time power loss: S25: Calculate the time of the power loss of the electric control inverter circuit by using the sliding time integration method to obtain the loss duration.

[0024] In the present invention, step S3 includes the following steps: S31: Calculate the loss of the field effect transistor of the electric control inverter circuit according to the safe operating area curve of the field effect transistor, combined with the thermal resistance of the radiator to obtain the steady-state allowable loss : ; S32: Perform dynamic correction on the steady-state allowable loss according to the ambient temperature to obtain the loss power threshold; S33: Classify and statistically analyze the occupancy time of the loss power threshold by using a sliding window to obtain the loss time threshold; S34: The monitoring and display unit of the controller displays the loss power threshold and the loss time threshold, and at the same time performs a dual-mode comparison with the real-time power loss and the loss duration, and stores them in the storage unit of the controller; In this embodiment, if the real-time power loss is higher than the loss power threshold and the loss duration is greater than or equal to the loss time threshold, then control the PWM duty cycle to increase and the voltage of the high-power output port of the electric control to increase; If the real-time power loss is lower than the loss power threshold and the loss duration is greater than or equal to the loss time threshold, then control the PWM duty cycle to decrease and the voltage of the high-power output port of the electric control to decrease; If the real-time power loss is equal to the loss power threshold, then set the upper and lower threshold bands of the loss time threshold and keep both the PWM duty cycle and the voltage of the high-power output port of the electric control unchanged; If the real-time power loss is not equal to the loss power threshold, or the loss duration is less than the loss time threshold, then keep both the PWM duty cycle and the voltage of the high-power output port of the electric control unchanged, and set a fast response window to suppress the transient peak loss of the voltage.

[0025] In the present invention, step S4 includes the following steps: S41: Establish a non - linear mapping model between the PWM duty cycle and the voltage of the electronically - controlled high - power output port according to the output characteristics of the field - effect transistor; In this embodiment, the output characteristics (ID - VDS characteristics) of the field - effect transistor are a kind of MOSFET static characteristics, which refer to the relationship between the drain - source voltage VDS and the drain current ID when the gate - source voltage VGS is constant.

[0026] Before the drain - source voltage VDS exceeds a specific value, the drain current ID increases as the drain - source voltage VDS increases. However, when the drain - source voltage VDS exceeds the specific value, the increase of the drain current ID does not depend on the drain - source voltage VDS, but on the value of the gate - source voltage VGS.

[0027] The "output characteristics (ID - VDS characteristics)" have three regions, namely the linear region, the saturation region, and the cut - off region. Among them, the voltage at the boundary between the linear region and the saturation region is called the pinch - off voltage VP.

[0028] Linear region: The region where the drain current ID increases as the drain - source voltage VDS increases.

[0029] Saturation region: The region where the drain current ID changes when the gate - source voltage VGS changes, and is independent of the drain - source voltage VDS.

[0030] Cut - off region: The region where the gate - source voltage VGS is lower than the gate threshold voltage VTH.

[0031] S42: Generate a duty - cycle - air - volume mapping table according to the static - pressure - air - volume curve of the fan and in combination with the non - linear mapping model; S43: Use a Hall sensor to detect the actual speed of the fan, and perform feedback regulation on the PWM duty cycle in combination with a proportional - derivative controller; S44: Regulate the fan speed according to the duty - cycle - air - volume mapping table and the ambient temperature, and in combination with a multi - level speed - regulation mechanism, thereby completing the drive control of the fan.

[0032] In the present invention, the working process of the multi - level speed - regulation mechanism is as follows: A: Establish a thermal inertia network model of the inverter circuit according to the ambient temperature and the junction temperature of the field - effect transistor, in combination with the loss - power threshold and the loss - time threshold; B: Simulate and verify the thermal inertia network model with the static - pressure - air - volume curve to obtain the air - volume - thermal - inertia - time curve; C: Divide the speed - regulation intervals by using fuzzy clustering analysis according to the duty - cycle - air - volume mapping table: In the steep - change region where the air - volume change rate is greater than or equal to the air - volume threshold, set a dense grading with every m% duty cycle as one grade; In the gentle region where the air volume change rate is less than the air volume threshold, a wide-interval grading with a duty cycle of 2m% per grade is set. D: Discretize the air volume-thermal inertia-time curve into a heat dissipation state space equation, predict the real-time power loss, and generate a prediction result. E: According to the prediction result and in combination with the speed regulation range, pre-adjust the PWM duty cycle M τ cycles in advance, and then complete the multi-stage speed regulation of the fan.

[0033] Embodiment: The input power unit and output power unit of the controller use the temperature compensation algorithm according to the temperature sensor to correct the sampling offset error in real time. The input power unit uses the synchronous sampling strategy to collect the voltage signal and current signal on the DC side of the inverter circuit in real time to obtain the input voltage signal and input current signal. The output power unit uses the synchronous sampling strategy to collect the voltage signal and current signal on the AC side of the inverter circuit in real time to obtain the output voltage signal and output current signal. The input voltage signal, input current signal, output voltage signal, and output current signal are denoised and smoothed using the moving average filtering method and the moving window mean method in sequence to obtain single-phase voltage, single-phase current, three-phase voltage, and three-phase current.

[0034] The operation unit of the controller calculates the DC side power according to the single-phase voltage and single-phase current in combination with the dead time compensation coefficient. The operation unit calculates the AC side power according to the three-phase voltage and three-phase current, and converts the three-phase coordinate system on the AC side to a two-phase rotating coordinate system using the Clarke-Park transformation algorithm. The loss calculation unit of the controller calculates the power loss of the electric control inverter circuit according to the motor operation mode to obtain the power loss value. Temperature compensation is performed on the power loss value according to the junction temperature of the field effect transistor to obtain the real-time power loss. The moving time integration method is used to calculate the time of the power loss of the electric control inverter circuit to obtain the loss duration.

[0035] According to the safe operating area curve of the field effect transistor and in combination with the heat resistance of the radiator, calculate the loss of the field effect transistor in the electric control inverter circuit to obtain the steady-state allowable loss. Dynamically correct the steady-state allowable loss according to the ambient temperature to obtain the loss power threshold. Use a sliding window to classify and count the occupancy time of the loss power threshold to obtain the loss time threshold. The monitoring and display unit of the controller displays the loss power threshold and the loss time threshold, and at the same time performs a dual-mode comparison with the real-time power loss and the loss duration, and stores them in the storage unit of the controller: If the real-time power loss is higher than the loss power threshold and the loss duration is greater than or equal to the loss time threshold, then control the PWM duty cycle to increase and the voltage of the high-power output port of the electric control to increase. If the real-time power loss is lower than the loss power threshold and the loss duration is greater than or equal to the loss time threshold, then control the PWM duty cycle to decrease and the voltage of the electronically controlled high-power output port to decrease; If the real-time power loss is equal to the loss power threshold, then set the upper and lower threshold bands of the loss time threshold and keep both the PWM duty cycle and the voltage of the electronically controlled high-power output port unchanged; If the real-time power loss is not equal to the loss power threshold or the loss duration is less than the loss time threshold, then keep both the PWM duty cycle and the voltage of the electronically controlled high-power output port unchanged and set a fast response window to suppress the transient peak loss of the voltage.

[0036] According to the output characteristics of the field-effect transistor, establish a non-linear mapping model between the PWM duty cycle and the voltage of the electronically controlled high-power output port; according to the static pressure-air volume curve of the fan, combine with the non-linear mapping model to generate a duty cycle-air volume mapping table; use a Hall sensor to detect the actual speed of the fan and combine with a proportional-derivative controller to perform feedback regulation on the PWM duty cycle; according to the duty cycle-air volume mapping table and the ambient temperature, combine with a multi-stage speed regulation mechanism: according to the ambient temperature and the junction temperature of the field-effect transistor, combine with the loss power threshold and the loss time threshold to establish a thermal inertia network model of the inverter circuit; simulate and verify the thermal inertia network model with the static pressure-air volume curve to obtain an air volume-thermal inertia-time curve; according to the duty cycle-air volume mapping table, use fuzzy clustering analysis to divide the speed regulation interval: In the steep change region where the air volume change rate is greater than or equal to the air volume threshold, set a dense grading with a duty cycle of every m% as one grade; In the gentle region where the air volume change rate is less than the air volume threshold, set a wide interval grading with a duty cycle of every 2m% as one grade; Discretize the air volume-thermal inertia-time curve into a heat dissipation state space equation, predict the real-time power loss, and generate a prediction result; according to the prediction result and the speed regulation interval, pre-adjust the PWM duty cycle 3 τ cycles in advance, and then complete the multi-stage speed regulation of the fan, and then complete the drive control of the fan.

Claims

1. An intelligent control method for driving a cooling fan, characterized in that: Including the following steps: S1: The controller performs power sampling and dynamic calibration on the DC side and the AC side of the inverter circuit respectively to obtain the corresponding voltage and current; S2: Calculate the corresponding power and power loss value according to the voltage and current on both sides, and perform temperature compensation on the power loss value according to the junction temperature of the field effect transistor to obtain the real-time power loss, and record the loss duration; S3: According to the ambient temperature, preset the loss power threshold and loss time threshold of the field effect transistor of the electric control inverter circuit, compare them with the real-time power loss and loss duration, and store them in the controller at the same time; S4: Establish a non-linear mapping model between the PWM duty cycle and the voltage of the high-power output port of the electric control, and regulate the fan speed in combination with the multi-stage speed regulation mechanism, so as to complete the drive control of the fan.

2. The intelligent control method for driving a cooling fan according to claim 1, wherein: The steps in step S1 include the following steps: S11: Use the temperature compensation algorithm according to the temperature sensor to correct the sampling offset error of the input power unit and the output power unit of the controller in real time; S12: The input power unit uses the synchronous sampling strategy to collect the voltage signal and current signal on the DC side of the inverter circuit in real time to obtain the input voltage signal and input current signal; S13: The output power unit uses the synchronous sampling strategy to collect the voltage signal and current signal on the AC side of the inverter circuit in real time to obtain the output voltage signal and output current signal; S14: Use the moving average filtering method and the moving window mean method to denoise and smooth the input voltage signal, input current signal, output voltage signal and output current signal in turn to obtain single-phase voltage, single-phase current, three-phase voltage and three-phase current.

3. The intelligent control method for driving a cooling fan according to claim 1, wherein: The steps in step S2 include the following steps: S21: The arithmetic unit of the controller calculates the DC side power according to the single-phase voltage and single-phase current, combined with the dead time compensation coefficient; S22: The arithmetic unit converts the three-phase coordinate system on the AC side to a two-phase rotating coordinate system according to the three-phase voltage and three-phase current, combined with the Clarke-Park transformation algorithm, and calculates the AC side power; S23: The loss calculation unit of the controller calculates the power loss of the electric control inverter circuit according to the motor operation mode to obtain the power loss value; S24: Perform temperature compensation on the power loss value according to the junction temperature of the field effect transistor to obtain the real-time power loss: S25: Use the sliding time integration method to calculate the time of the power loss of the electric control inverter circuit to obtain the loss duration.

4. The intelligent control method for driving a cooling fan according to claim 1, wherein: The steps in step S3 include the following steps: S31: Calculate the loss of the field effect transistor of the electric control inverter circuit according to the safe operating area curve of the field effect transistor, combined with the heat resistance of the radiator, to obtain the steady-state allowable loss; S32: Dynamically correct the steady-state allowable loss according to the ambient temperature to obtain the loss power threshold; S33: Use the sliding window to classify and count the occupancy time of the loss power threshold to obtain the loss time threshold; S34: The monitoring and display unit of the controller displays the loss power threshold and the loss time threshold, and performs dual-mode comparison with the real-time power loss and loss duration at the same time, and stores them in the storage unit of the controller.

5. The intelligent control method for driving a cooling fan according to claim 1, wherein: The steps in step S3 include the following steps: If the real-time power loss is higher than the loss power threshold and the loss duration is greater than or equal to the loss time threshold, then control the PWM duty cycle to increase and the voltage of the electronically controlled high-power output port to increase; If the real-time power loss is lower than the loss power threshold and the loss duration is greater than or equal to the loss time threshold, then control the PWM duty cycle to decrease and the voltage of the electronically controlled high-power output port to decrease; If the real-time power loss is equal to the loss power threshold, then set the upper and lower threshold bands of the loss time threshold and keep both the PWM duty cycle and the voltage of the electronically controlled high-power output port unchanged; If the real-time power loss is not equal to the loss power threshold, or the loss duration is less than the loss time threshold, then keep both the PWM duty cycle and the voltage of the electronically controlled high-power output port unchanged and set a fast response window to suppress the transient peak loss of the voltage.

6. The intelligent control method for driving a cooling fan according to claim 1, wherein: The steps in step S4 include the following steps: S41: Establish a non-linear mapping model between the PWM duty cycle and the voltage of the electronically controlled high-power output port according to the output characteristics of the field effect transistor; S42: Generate a duty cycle-air volume mapping table according to the static pressure-air volume curve of the fan and in combination with the non-linear mapping model; S43: Use a Hall sensor to detect the actual speed of the fan and perform feedback regulation on the PWM duty cycle in combination with a proportional-derivative controller; S44: Regulate the fan speed according to the duty cycle-air volume mapping table and the ambient temperature in combination with a multi-stage speed regulation mechanism, thereby completing the drive control of the fan.

7. The intelligent control method for driving a cooling fan according to claim 1, characterized in that: The working process of the multi-stage speed regulation mechanism is as follows: A: Establish a thermal inertia network model of the inverter circuit according to the ambient temperature and the junction temperature of the field effect transistor in combination with the loss power threshold and the loss time threshold; B: Simulate and verify the thermal inertia network model with the static pressure-air volume curve to obtain an air volume-thermal inertia-time curve; C: Divide the speed regulation interval by using fuzzy clustering analysis according to the duty cycle-air volume mapping table: In the steep change region where the air volume change rate is greater than or equal to the air volume threshold, set a dense grading with each m% duty cycle as one grade; In the gentle region where the air volume change rate is less than the air volume threshold, set a wide interval grading with each 2m% duty cycle as one grade; D: Discretize the air volume-thermal inertia-time curve into a heat dissipation state space equation and predict the real-time power loss to generate a prediction result; E: Pre-adjust the PWM duty cycle in advance by M τ cycles according to the prediction result in combination with the speed regulation interval, thereby completing the multi-stage speed regulation of the fan.

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