Fan drive circuit, control method and variable frequency air conditioner

Abstract

This application relates to a fan drive circuit, control method, and variable frequency air conditioner. The method includes: a drive control circuit providing a current drive voltage to an electronic commutator fan and feeding back the current drive voltage to a main control unit; a speed acquisition unit providing the current actual speed of the electronic commutator fan to the main control unit; the main control unit determining a corresponding target adjustment mode based on the degree of fitting between the received current drive voltage, current actual speed, and a preset voltage-speed curve; and adjusting the circuit parameters of the drive control circuit according to the target adjustment mode. The circuit parameters include at least one of resistance value, control duty cycle, and control frequency. This eliminates the need for manual hardware testing and adjustment, saving manual testing costs and improving the matching efficiency of the electronic commutator fan. It solves the problem of low matching efficiency and high matching costs caused by manually testing and matching the drive circuit hardware of the electronic commutator fan.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, and in particular to a fan drive circuit, control method and variable frequency air conditioner. Background Technology

[0002] With the widespread application of inverter air conditioners, electronic commutator fans are commonly used components due to their high efficiency, quiet operation, and reliability. However, in complex application scenarios such as computer room air conditioning, the overall structure of inverter air conditioners often requires various non-standard customizations due to space constraints. This leads to frequent changes in fan size and model, as well as hardware matching tests. Because electronic commutator fans from different manufacturers and of different models often differ in motor internal resistance and control methods, the drive circuit of traditional electronic commutator fans always requires manual testing of the drive circuit output and subsequent hardware modifications to match the motor internal resistance and control method of the electronic commutator fan. This results in low matching efficiency and high matching costs for electronic commutator fans. Summary of the Invention

[0003] This application provides a fan drive circuit, control method, and variable frequency air conditioner to solve the problems of low matching efficiency and high matching cost caused by manually testing and matching the drive circuit hardware of an electronically commutated fan.

[0004] In a first aspect, this application provides a wind turbine drive circuit, the wind turbine drive circuit comprising: A drive control circuit is connected to the electronic commutating fan and the main control unit, respectively, for driving the electronic commutating fan and feeding back the current drive voltage driving the electronic commutating fan to the main control unit; A speed acquisition unit is connected to the electronic commutator fan and the main control unit, respectively, and is used to acquire the current actual speed of the electronic commutator fan and feed back the current actual speed of the electronic commutator fan to the main control unit. The main control unit is used to determine the corresponding target adjustment mode based on the fitting degree between the current driving voltage, the current actual speed and the preset voltage-speed curve, and adjust the circuit parameters of the drive control circuit according to the target adjustment mode. The circuit parameters include at least one of the following: resistance value, control duty cycle and control frequency.

[0005] Optionally, the drive control circuit includes an isolation circuit, a resistor unit, a feedback unit, and a capacitor unit. The input terminal of the isolation circuit is connected to the signal output terminal of the main control unit. The output terminal of the isolation circuit is connected to the first terminal of the resistor unit. The second terminal of the resistor unit is connected to the first control output terminal of the main control unit. The third terminal of the resistor unit is connected to the input terminal of the feedback unit, the input terminal of the electronic commutator fan, and the input terminal of the capacitor unit. The output terminal of the feedback unit is connected to the input terminal of the main control unit. The input terminal of the capacitor unit is also connected to the second control output terminal of the main control unit. The resistor unit supports adjustable resistance, and the feedback unit is used to feed back the current drive voltage output by the drive control circuit to the main control unit.

[0006] Optionally, the isolation circuit includes a first resistor, a second resistor, a switching device, and an isolator. The first end of the first resistor is connected to an external power supply, the second end of the first resistor is connected to the input side of the isolator and the first end of the switching device, the first end of the second resistor is connected to the signal output terminal of the main control unit, the second end of the second resistor is connected to the second end of the switching device, the third end of the switching device is grounded, and the output side of the isolator is connected to an internal operating power supply and the resistor unit.

[0007] Optionally, the feedback unit includes a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first capacitor, and an isolation chip. The first end of the third resistor is connected to the third end of the resistor unit and the input end of the electronic commutation fan. The second end of the third resistor is connected to the first end of the fourth resistor, the first end of the first capacitor, and the input end of the isolation chip. The second end of the fourth resistor and the second end of the first capacitor are grounded together. The first output end of the isolation chip outputs a first differential voltage to the main control unit through the fifth resistor. The second output end of the isolation chip outputs a second differential voltage to the main control unit through the sixth resistor. The main control unit determines the current driving voltage received at the input end of the electronic commutation fan based on the first differential voltage and the second differential voltage.

[0008] Optionally, the resistor unit includes an isolation module, a first digital potentiometer, and a second digital potentiometer. The input terminal of the isolation module is connected to the first control output terminal of the main control unit, the first output terminal of the isolation module is connected to the first input terminal of the first digital potentiometer, the second output terminal of the isolation module is connected to the first input terminal of the second digital potentiometer, the output terminal of the first digital potentiometer is also connected to the second input terminal of the second digital potentiometer, and the output terminal of the second digital potentiometer is grounded.

[0009] Optionally, the capacitor unit includes a seventh resistor, a transistor, a diode, a second capacitor, an electrolytic capacitor, and a relay. The first end of the seventh resistor is connected to the second control output terminal of the main control unit, the second end of the seventh resistor is connected to the base of the transistor, the collector of the transistor is connected to the anode of the diode, the first end of the second capacitor, and the first side of the relay, respectively, the emitter of the transistor is grounded, the cathode of the diode, the second end of the second capacitor, and the first side of the relay are also connected to the external power supply, and the second side of the relay is grounded through the electrolytic capacitor. When the fan drive circuit is powered on, the main control unit outputs a low-level signal to the capacitor unit when the electronic commutation fan is controlled in the first control mode, so as to disconnect the electrolytic capacitor from the drive control circuit; and outputs a high-level signal to the capacitor voltage when the electronic commutation fan is controlled in the second control mode, so as to connect the electrolytic capacitor to the drive control circuit.

[0010] Secondly, this application provides a wind turbine drive circuit control method, applied to the wind turbine drive circuit described above, the wind turbine drive circuit control method comprising: When the variable frequency air conditioner is powered on, obtain the current driving voltage and current actual speed of the electronic commutator fan inside the variable frequency air conditioner; The corresponding target adjustment mode is determined based on the degree of fit between the current driving voltage, the current actual speed, and the preset voltage-speed curve. Adjust the circuit parameters of the drive control circuit in the fan drive circuit according to the target adjustment mode.

[0011] Optionally, based on the degree of fit between the current driving voltage, the current actual speed, and the preset voltage-speed curve, a corresponding target adjustment mode is determined, including: Based on the minimum distance between the mapping point of the current driving voltage and the current actual speed to the preset voltage-speed curve and the preset voltage-speed curve, the degree of fit between the current driving voltage, the current actual speed and the preset voltage-speed curve is determined; When the fitting degree is greater than or equal to the first preset degree, the maintenance parameter mode is used as the target adjustment mode, wherein the maintenance parameter mode is used to maintain the circuit parameters of the drive control circuit unchanged. When the degree of fitting is greater than or equal to the second preset degree and less than the first preset degree, the parameter compensation mode is taken as the target adjustment mode, wherein the second preset degree is less than the first preset degree; If the degree of fitting is less than the second preset degree, the resistance adjustment mode is taken as the target adjustment mode.

[0012] Optionally, adjusting the circuit parameters of the drive control circuit in the fan drive circuit according to the target adjustment mode includes: When the target adjustment mode is parameter compensation mode, the current duty cycle and / or current control frequency of the drive control circuit are obtained; The compensation duty cycle is determined by summing the product of the duty cycle compensation coefficient and the voltage difference with the current duty cycle; and / or, the compensation control frequency is determined by summing the product of the frequency compensation coefficient and the voltage difference with the current control frequency. The drive control circuit is controlled to output a drive voltage to the electronic commutator fan according to the compensation duty cycle and / or the compensation control frequency.

[0013] Optionally, adjusting the circuit parameters of the drive control circuit in the fan drive circuit according to the target adjustment mode includes: When the target adjustment mode is the resistance adjustment mode, the internal resistance of the electronic commutation fan is determined based on the current driving voltage, the current duty cycle, the first current resistance value of the first digital potentiometer and the second current resistance value of the second digital potentiometer in the drive control circuit. Based on the desired voltage, the current duty cycle, and the internal resistance of the fan, determine the first target resistance value corresponding to the first digital potentiometer and the second target resistance value corresponding to the second digital potentiometer; Adjust the resistance parameters of the first digital potentiometer and the second digital potentiometer according to the first target resistance value and the second target resistance value, respectively.

[0014] Thirdly, this application provides a variable frequency air conditioner, which includes a fan drive circuit as described in any of the preceding claims.

[0015] Compared with the prior art, the technical solution provided in this application has the following advantages: The fan drive circuit provided in this application provides the current drive voltage to the electronic commutating fan through the drive control circuit and feeds back the current drive voltage of the electronic commutating fan to the main control unit. The speed acquisition unit provides the current actual speed of the electronic commutating fan to the main control unit. The main control unit determines the corresponding target adjustment mode based on the degree of fitting between the received current drive voltage, current actual speed and preset voltage-speed curve, and adjusts the circuit parameters of the drive control circuit according to the target adjustment mode. The circuit parameters include at least one of resistance value, control duty cycle and control frequency. Based on the above fan drive circuit, the drive voltage and actual speed of the electronic commutating fan are automatically detected, and the circuit parameters of the drive control circuit are automatically adjusted to match the electronic commutating fan in the fan drive circuit. There is no need for manual testing and adjustment of hardware, which saves manual testing costs and improves the matching efficiency of the electronic commutating fan. It solves the problem of low matching efficiency and high matching cost caused by manually testing and matching the drive circuit hardware of the electronic commutating fan. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0019] Figure 1 This is a schematic diagram of the structure of a fan drive circuit provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a fan drive circuit provided in an embodiment of this application; Figure 3 This is a schematic diagram of the feedback unit in the wind turbine drive circuit provided in the embodiments of this application; Figure 4 This is a schematic diagram of the structure of the resistor unit in the fan drive circuit provided in the embodiments of this application; Figure 5This is a schematic diagram of the capacitor unit in the wind turbine drive circuit provided in the embodiments of this application; Figure 6 A schematic flowchart illustrating a wind turbine drive circuit control method provided in an embodiment of this application; Figure 7 This is a schematic diagram illustrating the effect of a preset voltage-speed curve provided in an embodiment of this application; Figure 8 A schematic flowchart illustrating a wind turbine drive circuit control method provided in an embodiment of this application; Figure 9 This is a schematic diagram of the internal structure of an inverter air conditioner provided in an embodiment of this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0022] In one embodiment, refer to Figure 1 A wind turbine drive circuit is provided, the wind turbine drive circuit comprising: A drive control circuit 110 is connected to the electronic commutating fan 100 and the main control unit 130 respectively. It is used to drive the electronic commutating fan 100 and to feed back the current drive voltage of the electronic commutating fan 100 to the main control unit 130. The speed acquisition unit 120 is connected to the electronic commutator fan 100 and the main control unit 130 respectively. It is used to acquire the current actual speed of the electronic commutator fan 100 and feed back the current actual speed of the electronic commutator fan 100 to the main control unit 130. The main control unit 130 is used to determine the corresponding target adjustment mode based on the fitting degree between the current driving voltage, the current actual speed and the preset voltage-speed curve, and adjust the circuit parameters of the drive control circuit 110 according to the target adjustment mode. The circuit parameters include at least one of the following: resistance value, control duty cycle and control frequency.

[0023] Specifically, the drive control circuit 110 provides the current drive voltage to the electronic commutating fan 100 and feeds back the current drive voltage of the electronic commutating fan 100 to the main control unit 130. The speed acquisition unit 120 provides the current actual speed of the electronic commutating fan 100 to the main control unit 130. The main control unit 130 determines the corresponding target adjustment mode based on the degree of fitting between the received current drive voltage, current actual speed and preset voltage-speed curve, and adjusts the circuit parameters of the drive control circuit 110 according to the target adjustment mode. Based on the above fan drive circuit, the drive voltage and actual speed of the electronic commutating fan 100 are automatically detected, and the circuit parameters of the drive control circuit 110 are automatically adjusted to match the electronic commutating fan 100 in the fan drive circuit. There is no need for manual testing and adjustment of hardware, which saves manual testing costs and improves the matching efficiency of the electronic commutating fan 100. This solves the problem of low matching efficiency and high matching cost caused by manually testing and matching the drive circuit hardware of the electronic commutating fan 100.

[0024] In one embodiment, refer to Figure 2 The drive control circuit 110 includes an isolation circuit 111, a resistor unit 112, a feedback unit 113, and a capacitor unit 114. The input terminal of the isolation circuit 111 is connected to the signal output terminal of the main control unit 130. The output terminal of the isolation circuit 111 is connected to the first terminal of the resistor unit 112. The second terminal of the resistor unit 112 is connected to the first control output terminal of the main control unit 130. The third terminal of the resistor unit 112 is connected to the input terminal of the feedback unit 113, the input terminal of the electronic commutator fan 100, and the input terminal of the capacitor unit 114. The output terminal of the feedback unit 113 is connected to the input terminal of the main control unit 130. The input terminal of the capacitor unit 114 is also connected to the second control output terminal of the main control unit 130. The resistor unit 112 supports adjustable resistance, and the feedback unit 113 is used to feed back the current drive voltage output by the drive control circuit 110 to the main control unit.

[0025] Specifically, the isolation circuit 111 is used to isolate the input control signal and the output control signal of the drive control circuit 110 from each other, the resistor unit 112 supports adjustable resistance, the feedback unit 113 is used to collect the drive voltage output to the electronic commutation fan 100 and feed it back to the main control unit 130, and the capacitor unit 114 is used to select whether to connect to the drive control circuit 110 based on the control mode of the electronic commutation fan 100, that is, to control the connection state between the capacitor unit 114 and the drive control circuit 110 according to the control mode of the electronic commutation fan 100.

[0026] The isolation circuit 111 blocks the ground potential circulating current interference between the main control unit 130 and the subsequent drive circuit, reducing the coupling interference between high and low voltage circuits and effectively preventing strong interference from the electronic commutator fan 100 from flowing back into the main control unit 130 during operation, causing the main control program to crash or the sampling accuracy to be distorted. The resistor unit 112, which supports adjustable resistance, can be matched with electronic commutator fans 100 of different power levels and internal resistance specifications. The output drive signal amplitude can be accurately calibrated simply by adjusting the resistance parameters, without the need to redesign the circuit, greatly improving the adaptability and compatibility of the circuit solution. The feedback unit 113 collects the closed-loop drive voltage in real time. The feedback architecture allows the main control unit 130 to dynamically correct the output control signal based on the feedback value, offsetting the drive voltage offset caused by grid voltage fluctuations and device temperature drift, thus improving the stability of the fan operation. The selectable connection design of the capacitor unit 114 not only meets the requirements of disconnecting the capacitor to avoid phase offset and ensure speed control response in PWM speed control mode, but also supports the requirement of connecting the capacitor for filtering and reducing the output noise of the fan in linear speed control mode. It achieves the effect of adapting the same hardware circuit to two control methods. Compared with the fixed connection capacitor scheme, it can improve the response speed and reduce the fan operating noise, taking into account the requirements of speed control performance and quiet operation.

[0027] In one embodiment, refer to Figure 2 The isolation circuit 111 includes a first resistor R1, a second resistor R2, a switching device D1, and an isolator U1. The first end of the first resistor R1 is connected to an external power supply, and the second end of the first resistor R1 is connected to the input side of the isolator U1 and the first end of the switching device D1. The first end of the second resistor R2 is connected to the signal output terminal of the main control unit 130, and the second end of the second resistor R2 is connected to the second end of the switching device D1. The third end of the switching device D1 is grounded, and the output side of the isolator U1 is connected to the internal operating power supply and the resistor unit 112.

[0028] Specifically, at the front end of isolator U1, the input control signal controls the on / off state of switching device D1 through the second resistor R2. Both the first resistor R1 and the second resistor R2 are current-limiting resistors used to limit current. The external power supply is a low-voltage power supply VCC. At the rear end of isolator U1, the internal working power supply is a low-voltage power supply VDD. The isolation circuit 111 can achieve complete electrical isolation between the internal and external circuits. On the one hand, it can block surge interference and common-mode interference introduced by the external power supply line from entering the internal digital control circuit, preventing interference signals from damaging the pins of the main control unit 130 or causing control logic disorder, and ensuring the working stability of the core control circuit. On the other hand, when the external circuit suddenly experiences overvoltage or short-circuit faults, the isolator U1 can cut off the conduction path of fault energy to the internal circuit, limiting the impact of the fault to the external input side, preventing the internal core components from being damaged by fault voltage and current, and reducing the risk of system fault expansion. At the same time, relying on the electrical isolation characteristics of the isolator U1, it can also realize cross-potential domain signal transmission between the external weak current VCC and the internal weak current VDD, adapting to different potential reference designs of the internal and external circuits, meeting the signal reliable transmission requirements of multi-potential domain systems, and improving the circuit's ability to suppress signal distortion compared to direct signal transmission without isolation.

[0029] In one embodiment, refer to Figure 3 The feedback unit 113 includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first capacitor C1, and an isolation chip U2. The first end of the third resistor R3 is connected to the third end of the resistor unit 112 and the input end of the electronic commutation fan 100. The second end of the third resistor R3 is connected to the first end of the fourth resistor R4, the first end of the first capacitor C1, and the input end of the isolation chip U2. The second end of the fourth resistor R4 and the second end of the first capacitor C1 are grounded together. The first output end of the isolation chip U2 outputs a first differential voltage to the main control unit 130 through the fifth resistor R5. The second output end of the isolation chip U2 outputs a second differential voltage to the main control unit 130 through the sixth resistor R6. The main control unit 130 determines the current driving voltage received at the input end of the electronic commutation fan 100 based on the first differential voltage and the second differential voltage.

[0030] Specifically, the feedback unit 113 acquires the output information (Vout) of the drive control circuit 110, uses the third resistor R3 and the fourth resistor R4 for voltage division and the first capacitor C1 for filtering, and then passes through the isolation chip U2 and the fifth resistor R5 and the sixth resistor R6 to obtain the differential signals corresponding to the first differential voltage DIANYA1 and the second differential voltage DIANYA2. The differential signals can effectively suppress common-mode noise (such as switching interference from the motor drive circuit) and are more stable than single-ended sampling. The differential output of the isolation chip U2 also solves the potential difference problem between the power ground FGND and the digital ground GND, preventing high voltage from entering the main control side. The first differential voltage and the second differential voltage are used to represent the current drive voltage. That is, the main control unit 130 calculates and reconstructs the current drive voltage based on the first differential voltage and the second differential voltage, i.e., the current drive voltage is DIANYA = =( )× × , where k is the differential gain of the isolation chip U2.

[0031] This sampling calculation method can offset the common-mode drift error during line transmission, further improving the driving voltage sampling accuracy. Compared with the traditional single-ended sampling scheme, it can improve accuracy and provide accurate voltage feedback data for the closed-loop control of the electronic commutation fan 100, avoiding speed fluctuations and unstable output power caused by sampling deviations, and effectively extending the service life of the electronic commutation fan 100.

[0032] In one embodiment, refer to Figure 4 The resistor unit 112 includes an isolation module, a first digital potentiometer, and a second digital potentiometer. The input terminal of the isolation module is connected to the first control output terminal of the main control unit 130. The first output terminal of the isolation module is connected to the first input terminal of the first digital potentiometer. The second output terminal of the isolation module is connected to the first input terminal of the second digital potentiometer. The output terminal of the first digital potentiometer is also connected to the second input terminal of the second digital potentiometer. The output terminal of the second digital potentiometer is grounded.

[0033] Specifically, the isolation module is implemented using an IIC isolation module. The first and second digital potentiometers are connected in parallel, and both are adjustable rheostats for adjustable resistance. The IIC isolation module blocks ground loop interference between the main control unit 130 and the digital potentiometer branch, preventing the control signal of the main control unit 130 from being affected by clutter coupling from the analog tuning circuit. This significantly improves the transmission stability of the control signal and reduces the overall circuit noise floor. The parallel structure of the two digital potentiometers allows for finer resistance adjustment steps within the same total resistance adjustment range. Compared to a single digital potentiometer structure, the resistance adjustment resolution is doubled, meeting the requirements for precise resistance matching in high-precision tuning scenarios. Simultaneously, this structure retains the redundancy of independent dual-path adjustment. When one digital potentiometer experiences parameter drift or failure, the other can still maintain basic tuning functionality, effectively improving the overall reliability of the circuit and extending its stable operating cycle.

[0034] In one embodiment, refer to Figure 5 The capacitor unit 114 includes a seventh resistor R7, a transistor D2, a diode P1, a second capacitor C2, an electrolytic capacitor C3, and a relay K1. The first end of the seventh resistor R7 is connected to the second control output terminal of the main control unit 130, and the second end of the seventh resistor R7 is connected to the base of the transistor D2. The collector of the transistor D2 is connected to the anode of the diode P1, the first end of the second capacitor C2, and the first side of the relay K1. The emitter of the transistor D2 is grounded. The cathode of the diode P1, the second end of the second capacitor C2, and the first side of the relay K1 are also connected to the external power supply. The second side of the relay K1 is grounded through the electrolytic capacitor C3. When the fan drive circuit is powered on, the main control unit 130 outputs a low-level signal to the capacitor unit 114 when the control mode of the electronic commutation fan 100 is the first control mode, so as to disconnect the electrolytic capacitor C3 from the drive control circuit 110; and outputs a high-level signal to the capacitor voltage when the control mode of the electronic commutation fan 100 is the second control mode, so as to connect the electrolytic capacitor C3 to the drive control circuit 110.

[0035] Specifically, the second control signal (ctr2) output by the main control unit 130 controls the conduction of transistor D2, thereby controlling the closure of relay K1, so that electrolytic capacitor C3 can be controllably connected to the fan drive control circuit 110. Electrolytic capacitor C3 acts as an energy storage element and a smoothing filter, depending on whether the electronic commutation motor's control mode is pulse regulation or linear voltage control, and is selected for connection to the drive control circuit 110. When the electronic commutation fan 100's control mode is linear voltage control (second control mode), the main control unit 130 outputs a high-level signal to capacitor unit 114, relay K1 conducts, and electrolytic capacitor C3 is connected to the drive control circuit 110. Diode P1 and the second capacitor C2 provide protection. Utilizing the large-capacity energy storage characteristics of electrolytic capacitor C3, it absorbs the small voltage fluctuations generated by the drive control circuit 110 under linear voltage control mode, preventing voltage ripple from causing unstable output torque of the electronic commutation fan 100, reducing vibration and noise during operation, and maintaining the output speed at a stable target value.

[0036] When the electronic commutator motor is controlled by pulse regulation, the main control unit 130 outputs a low-level signal to the capacitor unit 114, the relay K1 is turned off, and the electrolytic capacitor C3 is prevented from being connected to the drive control circuit 110. This avoids the charging and discharging process of the large-capacity electrolytic capacitor C3 slowing down the response speed of the pulse signal, ensuring that the drive circuit can quickly follow the control signal to adjust the output state in pulse regulation mode, meeting the dynamic response requirements of pulse speed regulation. It also avoids the additional power loss caused by the continuous charging and discharging of the electrolytic capacitor C3, improving the energy conversion efficiency of the entire fan drive circuit. The combination of diode P1 and the second capacitor C2 can also absorb the reverse induced electromotive force generated during the switching process of relay K1, preventing the induced peak voltage from breaking down the transistor D2 or interfering with the control signal output of the main control unit 130, thus improving the operational stability and service life of the entire capacitor unit 114 and drive control circuit 110.

[0037] In one embodiment, Figure 6 This is a flowchart illustrating a wind turbine drive circuit control method in one embodiment, with reference to... Figure 6 A method for controlling a wind turbine drive circuit is provided. This embodiment mainly applies this method to the above-mentioned... Figure 1 Taking the main control unit 130 in the fan drive circuit as an example, the fan drive circuit is applied to a variable frequency air conditioner, and the control method of this fan drive circuit specifically includes the following steps: Step S210: When the inverter air conditioner is powered on, obtain the current driving voltage and current actual speed of the electronic commutator fan 100 inside the inverter air conditioner.

[0038] Specifically, the current driving voltage of the electronically commutated fan 100 is obtained through the drive control circuit 110 in the fan drive circuit, and the current actual speed of the electronically commutated fan 100 is obtained through the speed acquisition unit 120 in the fan drive circuit.

[0039] Step S220: Determine the corresponding target adjustment mode based on the current driving voltage, the degree of fitting between the current actual speed and the preset voltage-speed curve.

[0040] Specifically, the current driving voltage and current actual speed are fitted and compared with the preset voltage-speed curve to determine the degree of fit. The preset voltage-speed curve is as follows: Figure 7 As shown, the degree of fitting is used to represent the difference between the current actual operating state of the electronic commutating fan 100 and the expected operating state under the same operating conditions on the preset voltage-speed curve. Based on this degree of difference, the corresponding target adjustment mode is determined. The target adjustment mode is used to make the actual operating state of the electronic commutating fan 100 close to the expected operating state under the same operating conditions on the preset voltage-speed curve.

[0041] Step S230: Adjust the circuit parameters of the drive control circuit 110 in the fan drive circuit according to the target adjustment mode.

[0042] Specifically, the circuit parameters of the drive control circuit 110 are adjusted according to the target adjustment mode to match the adjusted drive control circuit 110 with the electronic commutating fan 100, so that the actual operating state of the electronic commutating fan 100 is close to the expected operating state under the same operating conditions on the preset voltage-speed curve. By automatically detecting the drive voltage and actual speed of the electronic commutating fan 100 and automatically adjusting the circuit parameters of the drive control circuit 110 to match the electronic commutating fan 100 in the fan drive circuit, manual testing and adjustment of the hardware is eliminated, saving manual testing costs and improving the matching efficiency of the electronic commutating fan 100. This solves the problem of low matching efficiency and high matching cost caused by manually testing and matching the drive circuit hardware of the electronic commutating fan 100.

[0043] In one embodiment, refer to Figure 8 Based on the degree of fit between the current driving voltage, the current actual speed, and the preset voltage-speed curve, a corresponding target adjustment mode is determined, including: Based on the minimum distance between the mapping point of the current driving voltage and the current actual speed to the preset voltage-speed curve and the preset voltage-speed curve, the degree of fit between the current driving voltage, the current actual speed and the preset voltage-speed curve is determined; When the fitting degree is greater than or equal to the first preset degree, the maintenance parameter mode is used as the target adjustment mode, wherein the maintenance parameter mode is used to keep the circuit parameters of the drive control circuit 110 unchanged. When the degree of fitting is greater than or equal to the second preset degree and less than the first preset degree, the parameter compensation mode is taken as the target adjustment mode, wherein the second preset degree is less than the first preset degree; If the degree of fitting is less than the second preset degree, the resistance adjustment mode is taken as the target adjustment mode.

[0044] Specifically, based on the minimum distance between the mapping point of the current driving voltage and the current actual speed on the preset voltage-speed curve and the preset voltage-speed curve, the degree of difference between the actual operating state of the electronic commutation fan 100 and the expected operating state under the same operating conditions on the preset voltage-speed curve is determined. The smaller the minimum distance, the smaller the difference and the higher the degree of fit; conversely, the larger the minimum distance, the larger the difference and the lower the degree of fit. That is, the degree of fit is negatively correlated with the minimum distance, thus determining the degree of fit between the current driving voltage, the current actual speed and the preset voltage-speed curve.

[0045] The adjustment mode corresponding to the range of fitting degree is used as the target adjustment mode. For example, when the fitting degree is greater than or equal to a first preset degree (e.g., 95%), the parameter maintenance mode is used as the target adjustment mode to keep the circuit parameters of the drive control circuit 110 unchanged; when the fitting degree is greater than or equal to a second preset degree (e.g., 80%) and less than the first preset degree, the parameter compensation mode is used as the target adjustment mode to compensate the control parameters of the drive control circuit 110; when the fitting degree is less than the second preset degree, the resistance adjustment mode is used as the target adjustment mode to adjust the resistance parameters of the drive control circuit 110.

[0046] Based on the hierarchical matching adjustment method, the response accuracy and efficiency of the electronic commutator fan 100's operating status adjustment can be significantly improved. For operating conditions with high fitting degree, maintaining the circuit parameters unchanged can avoid unnecessary adjustment actions, eliminate speed fluctuations caused by redundant adjustments, and ensure that the fan always maintains stable operating output, reducing the ineffective computing power consumption of the control module. For operating conditions with moderate deviation, only soft compensation is performed on the control parameters without adjusting the hardware circuit parameters. This can quickly correct speed deviations and avoid aging and wear caused by frequent hardware parameter adjustments. The adjustment response speed is faster than directly adjusting the hardware resistor. For severe deviations exceeding the threshold, the hardware resistor parameters are directly adjusted to correct the long-term accumulated resistance aging and drift problem from the root. This solves the defect that soft compensation alone cannot completely eliminate hardware deviations, extends the overall service life of the electronic commutator fan 100, and ensures that the electronic commutator fan 100 maintains the operating performance that meets the design requirements throughout its entire life cycle.

[0047] In one embodiment, refer to Figure 8 Adjusting the circuit parameters of the drive control circuit 110 in the fan drive circuit according to the target adjustment mode includes: When the target adjustment mode is parameter compensation mode, the current duty cycle and / or current control frequency of the drive control circuit 110 are obtained; The compensation duty cycle is determined by summing the product of the duty cycle compensation coefficient and the voltage difference with the current duty cycle; and / or, the compensation control frequency is determined by summing the product of the frequency compensation coefficient and the voltage difference with the current control frequency. The drive control circuit 110 is controlled to output a drive voltage to the electronic commutator fan 100 according to the compensation duty cycle and / or the compensation control frequency.

[0048] Specifically, when the target adjustment mode is parameter compensation mode, the current duty cycle DUTE and / or the current control frequency FRE of the drive control circuit 110 are obtained. Compensation processing can be performed only on the duty cycle, or only on the control frequency, or both the duty cycle and the control frequency can be compensated simultaneously.

[0049] The duty cycle is compensated, and the compensated duty cycle is DUTE1 = DUTE + a. (DIANYA0-DIANYA), where DIANYA is the current driving voltage, DIANYA0 is the expected voltage under the corresponding operating conditions, and a is the duty cycle compensation coefficient, which is determined in conjunction with the fan type of the electronic commutation fan 100.

[0050] The control frequency is compensated, and the compensated control frequency is FRE1 = FRE + b. (DIANYA0-DIANYA), where b is the frequency compensation coefficient, which is specifically determined in conjunction with the fan type of the electronic commutation fan 100.

[0051] In the next instant, the drive control circuit 110 outputs a drive voltage to the electronically commutated fan 100 according to the compensation duty cycle and / or compensation control frequency to adjust the drive voltage so that the adjusted drive voltage is close to the corresponding desired voltage. This adjustment method corrects the circuit parameters through linear compensation, without requiring modification of the original preset parameter table of the drive circuit. Voltage correction can be quickly completed using only the preset compensation coefficient. While ensuring the accuracy of the drive voltage output, it reduces the response delay of parameter adjustment, making it suitable for variable operating conditions with frequent speed fluctuations. It also adapts to single-parameter adjustment and dual-parameter coordinated adjustment schemes, allowing the selection of the corresponding compensation path according to the drive characteristics of different power levels of fans. For small-power fans, only the duty cycle needs to be adjusted to control the steady-state error of the drive voltage. For large-power fans, the duty cycle and frequency are used for coordinated compensation, which can reduce the overshoot of the drive voltage, thus balancing control accuracy and operational stability in different scenarios.

[0052] In one embodiment, refer to Figure 8 Adjusting the circuit parameters of the drive control circuit 110 in the fan drive circuit according to the target adjustment mode includes: When the target adjustment mode is the resistance adjustment mode, the internal resistance of the electronic commutation fan 100 is determined based on the current driving voltage, the current duty cycle, the first current resistance value of the first digital potentiometer and the second current resistance value of the second digital potentiometer in the drive control circuit 110. Based on the desired voltage, the current duty cycle, and the internal resistance of the fan, determine the first target resistance value corresponding to the first digital potentiometer and the second target resistance value corresponding to the second digital potentiometer; Adjust the resistance parameters of the first digital potentiometer and the second digital potentiometer according to the first target resistance value and the second target resistance value, respectively.

[0053] Specifically, when the target adjustment mode is resistance adjustment mode, the internal resistance of the electronic commutation fan 100 is first calculated based on the current driving voltage, the current duty cycle, the first current resistance value of the first digital potentiometer and the second current resistance value of the second digital potentiometer in the drive control circuit 110. The formula for calculating the internal resistance of the fan is DIANYA = DUTE. VDD (r2 / / ) / (r2 / / +r1), where r1 is the resistance value of the first digital potentiometer and r2 is the resistance value of the second digital potentiometer. For the internal resistance of the fan, r2 / / Given the parallel resistance of the first digital potentiometer and the internal resistance of the fan, and based on the above formula, the current driving voltage, current duty cycle, voltage of the internal power supply, first current resistance of the first digital potentiometer, and second current resistance of the second digital potentiometer, calculate the internal resistance of the fan. .

[0054] Knowing the internal resistance of the fan, and based on the above formula, replace the current driving voltage with the desired voltage, and reverse the deduction to find the first target resistance value corresponding to the first digital potentiometer and the second target resistance value corresponding to the second digital potentiometer, i.e., according to DIANYA0=DUTE VDD (r2 / / ) / (r2 / / +r1), calculate r1 and r2 in reverse. Based on this formula, at least one resistance pair can be obtained. That is, the resistance pair contains the first target resistance value and the second target resistance value. The combination of the first target resistance value and the second target resistance value in different resistance pairs is different. The resistance values ​​of the first digital potentiometer and the second digital potentiometer can be adjusted according to the target resistance value in any resistance pair. Then, the adjusted driving voltage will be output in the next moment. Then, based on the driving voltage, it is continuously determined whether the circuit parameters of the driving control circuit 110 need to be adjusted.

[0055] This method, which uses dual digital potentiometers and formulas to calculate and adjust parameters, can accurately offset the impact of individual internal resistance differences of different electronic commutator fans 100 and the drift changes in internal resistance after long-term operation on the accuracy of the drive voltage output. It can control the steady-state error of the drive voltage to be better than the error level of traditional fixed-parameter drive circuits. At the same time, the entire adjustment process is automatically calculated and updated by the circuit, eliminating the need for manual disassembly and calibration, greatly improving calibration efficiency and reducing the labor costs of after-sales maintenance. In addition, this adjustment scheme can achieve output calibration simply by adjusting the resistance value of the digital potentiometer in the existing drive control circuit 110, without the need to add complex signal amplification or compensation circuits. It does not introduce additional signal noise, nor does it change the original bandwidth of the drive circuit. While ensuring the accuracy of the drive voltage, it maintains the original speed response speed and operational stability of the electronic commutator fan 100.

[0056] Figure 6 and Figure 8 This is a flowchart illustrating a wind turbine drive circuit control method in one embodiment. It should be understood that, although... Figure 6 and Figure 8 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 6 and Figure 8 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0057] It should be noted that the examples and application scenarios implemented by the above modules and corresponding steps are the same, but are not limited to the content disclosed in the above embodiments. It should also be noted that the above modules, as part of a device, can operate in environments such as... Figure 1 The hardware environment shown can be implemented either through software or through hardware.

[0058] In one embodiment, a variable frequency air conditioner is provided, the variable frequency air conditioner including the fan drive circuit described in any of the above embodiments.

[0059] like Figure 9 As shown, this application embodiment provides a variable frequency air conditioner, including a processor 711, a communication interface 712, a memory 713, and a communication bus 714. The processor 711, the communication interface 712, and the memory 713 communicate with each other through the communication bus 714. The memory 713 is used to store computer programs. When the processor 711 executes the program stored in the memory 713, it implements the fan drive circuit control method provided in any of the aforementioned method embodiments.

[0060] The memory and processor in the aforementioned electronic devices communicate with each other via a communication bus and a communication interface. The communication bus can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into an address bus, a data bus, a control bus, etc.

[0061] The memory may include random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0062] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0063] Those skilled in the art will understand that Figure 9 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the variable frequency air conditioner to which the present application is applied. A specific variable frequency air conditioner may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0064] According to another aspect of the embodiments of this application, a computer program product or computer program is also provided, which includes computer instructions stored in a computer-readable storage medium. The processor of an inverter air conditioner reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the inverter air conditioner to perform the steps of any of the above embodiments.

[0065] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the wind turbine drive circuit control method provided in any of the foregoing method embodiments.

[0066] Optionally, in embodiments of this application, the computer-readable medium is configured to store program code for the processor to perform the following steps: When the variable frequency air conditioner is powered on, obtain the current driving voltage and current actual speed of the electronic commutator fan 100 inside the variable frequency air conditioner; The corresponding target adjustment mode is determined based on the degree of fit between the current driving voltage, the current actual speed, and the preset voltage-speed curve. Adjust the circuit parameters of the drive control circuit 110 in the fan drive circuit according to the target adjustment mode.

[0067] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments, and will not be repeated here.

[0068] It is understood that the embodiments described herein can be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described herein, or combinations thereof.

[0069] For software implementation, the techniques described herein can be implemented by units that perform the functions described herein. The software code can be stored in memory and executed by a processor. The memory can be implemented in the processor or external to the processor.

[0070] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0071] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0072] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0073] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0074] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0075] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented using software plus a general-purpose hardware platform, or of course, using hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a USB flash drive, mobile hard drive, ROM, RAM, magnetic disk, or optical disk, or other media capable of storing program code, including several instructions to cause an inverter air conditioner (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0076] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also mean including the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that alternatives or substitutions may be used.

[0077] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A fan drive circuit, characterized in that, The wind turbine drive circuit includes: A drive control circuit is connected to the electronic commutating fan and the main control unit, respectively, for driving the electronic commutating fan and feeding back the current drive voltage driving the electronic commutating fan to the main control unit; A speed acquisition unit is connected to the electronic commutator fan and the main control unit, respectively, and is used to acquire the current actual speed of the electronic commutator fan and feed back the current actual speed of the electronic commutator fan to the main control unit. The main control unit is used to determine the corresponding target adjustment mode based on the fitting degree between the current driving voltage, the current actual speed and the preset voltage-speed curve, and adjust the circuit parameters of the drive control circuit according to the target adjustment mode. The circuit parameters include at least one of the following: resistance value, control duty cycle and control frequency.

2. The fan drive circuit according to claim 1, characterized in that, The drive control circuit includes an isolation circuit, a resistor unit, a feedback unit, and a capacitor unit. The input terminal of the isolation circuit is connected to the signal output terminal of the main control unit. The output terminal of the isolation circuit is connected to the first terminal of the resistor unit. The second terminal of the resistor unit is connected to the first control output terminal of the main control unit. The third terminal of the resistor unit is connected to the input terminal of the feedback unit, the input terminal of the electronic commutator fan, and the input terminal of the capacitor unit. The output terminal of the feedback unit is connected to the input terminal of the main control unit. The input terminal of the capacitor unit is also connected to the second control output terminal of the main control unit. The resistor unit supports adjustable resistance, and the feedback unit is used to feed back the current drive voltage output by the drive control circuit to the main control unit.

3. The fan drive circuit according to claim 2, characterized in that, The isolation circuit includes a first resistor, a second resistor, a switching device, and an isolator. The first end of the first resistor is connected to an external power supply. The second end of the first resistor is connected to the input side of the isolator and the first end of the switching device. The first end of the second resistor is connected to the signal output terminal of the main control unit. The second end of the second resistor is connected to the second end of the switching device. The third end of the switching device is grounded. The output side of the isolator is connected to the internal operating power supply and the resistor unit.

4. The fan drive circuit according to claim 2, characterized in that, The feedback unit includes a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first capacitor, and an isolation chip. The first end of the third resistor is connected to the third end of the resistor unit and the input end of the electronic commutation fan. The second end of the third resistor is connected to the first end of the fourth resistor, the first end of the first capacitor, and the input end of the isolation chip. The second end of the fourth resistor and the second end of the first capacitor are grounded together. The first output end of the isolation chip outputs a first differential voltage to the main control unit through the fifth resistor. The second output end of the isolation chip outputs a second differential voltage to the main control unit through the sixth resistor. The main control unit determines the current driving voltage received at the input end of the electronic commutation fan based on the first differential voltage and the second differential voltage.

5. The fan drive circuit according to claim 2, characterized in that, The resistor unit includes an isolation module, a first digital potentiometer, and a second digital potentiometer. The input terminal of the isolation module is connected to the first control output terminal of the main control unit. The first output terminal of the isolation module is connected to the first input terminal of the first digital potentiometer. The second output terminal of the isolation module is connected to the first input terminal of the second digital potentiometer. The output terminal of the first digital potentiometer is also connected to the second input terminal of the second digital potentiometer. The output terminal of the second digital potentiometer is grounded.

6. The fan drive circuit according to claim 2, characterized in that, The capacitor unit includes a seventh resistor, a transistor, a diode, a second capacitor, an electrolytic capacitor, and a relay. The first end of the seventh resistor is connected to the second control output terminal of the main control unit, and the second end of the seventh resistor is connected to the base of the transistor. The collector of the transistor is connected to the anode of the diode, the first end of the second capacitor, and the first side of the relay. The emitter of the transistor is grounded. The cathode of the diode, the second end of the second capacitor, and the first side of the relay are also connected to an external power supply. The second side of the relay is grounded through the electrolytic capacitor. When the fan drive circuit is powered on, the main control unit outputs a low-level signal to the capacitor unit when the electronic commutation fan is controlled in the first control mode, so as to disconnect the electrolytic capacitor from the drive control circuit; and outputs a high-level signal to the capacitor voltage when the electronic commutation fan is controlled in the second control mode, so as to connect the electrolytic capacitor to the drive control circuit.

7. A method for controlling a fan drive circuit, characterized in that, The wind turbine drive circuit control method, applied to the wind turbine drive circuit as described in claim 1, includes: When the variable frequency air conditioner is powered on, obtain the current driving voltage and current actual speed of the electronic commutator fan inside the variable frequency air conditioner; The corresponding target adjustment mode is determined based on the degree of fit between the current driving voltage, the current actual speed, and the preset voltage-speed curve. Adjust the circuit parameters of the drive control circuit in the fan drive circuit according to the target adjustment mode.

8. The method according to claim 7, characterized in that, Based on the degree of fit between the current driving voltage, the current actual speed, and the preset voltage-speed curve, a corresponding target adjustment mode is determined, including: Based on the minimum distance between the mapping point of the current driving voltage and the current actual speed on the preset voltage-speed curve and the preset voltage-speed curve, the degree of fit between the current driving voltage, the current actual speed and the preset voltage-speed curve is determined; When the fitting degree is greater than or equal to the first preset degree, the maintenance parameter mode is used as the target adjustment mode, wherein the maintenance parameter mode is used to keep the circuit parameters of the drive control circuit unchanged. When the degree of fitting is greater than or equal to the second preset degree and less than the first preset degree, the parameter compensation mode is taken as the target adjustment mode, wherein the second preset degree is less than the first preset degree; If the degree of fitting is less than the second preset degree, the resistance adjustment mode is taken as the target adjustment mode.

9. The method according to claim 8, characterized in that, Adjusting the circuit parameters of the drive control circuit in the fan drive circuit according to the target adjustment mode includes: When the target adjustment mode is parameter compensation mode, the current duty cycle and / or current control frequency of the drive control circuit are obtained; The compensation duty cycle is determined by summing the product of the duty cycle compensation coefficient and the voltage difference with the current duty cycle; and / or, the compensation control frequency is determined by summing the product of the frequency compensation coefficient and the voltage difference with the current control frequency. The drive control circuit is controlled to output a drive voltage to the electronic commutator fan according to the compensation duty cycle and / or the compensation control frequency.

10. The method according to claim 8, characterized in that, Adjusting the circuit parameters of the drive control circuit in the fan drive circuit according to the target adjustment mode includes: When the target adjustment mode is the resistance adjustment mode, the internal resistance of the electronic commutation fan is determined based on the current driving voltage, the current duty cycle, the first current resistance value of the first digital potentiometer and the second current resistance value of the second digital potentiometer in the drive control circuit. Based on the desired voltage, the current duty cycle, and the internal resistance of the fan, determine the first target resistance value corresponding to the first digital potentiometer and the second target resistance value corresponding to the second digital potentiometer; Adjust the resistance parameters of the first digital potentiometer and the second digital potentiometer according to the first target resistance value and the second target resistance value, respectively.

11. A variable frequency air conditioner, characterized in that, The variable frequency air conditioner includes the fan drive circuit as described in any one of claims 1-6.

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