PFC circuit control method and device, frequency converter and storage medium

Abstract

The application provides a PFC circuit control method and device, a frequency converter and a storage medium. The method comprises the following steps: when a power factor correction (PFC) circuit is in a critical mode, determining an inductance value of an inductor in the PFC circuit; and controlling the operation of the PFC circuit by adjusting the inductance value. Through the application, the technical problem of inductance loss and electromagnetic interference of the power factor correction circuit caused by factors such as an increase in grid harmonic current and a sharp change in voltage and current at the highest point and zero-crossing point of voltage is solved.

Description

Technical Field

[0001] This application relates to the field of frequency converters, and more particularly to a PFC circuit control method, device, frequency converter, and storage medium. Background Technology

[0002] With the widespread use of frequency converters, problems such as increased grid harmonic current and EMI (electromagnetic interference) caused by rapid changes in voltage and current have led to increasingly stringent requirements for the power factor correction (PFC) circuits of equipment. The PFC circuits also face technical challenges at the voltage peak and zero crossing points due to factors such as increased grid harmonic current and rapid changes in voltage and current, resulting in inductance loss and electromagnetic interference. Summary of the Invention

[0003] In order to solve the above-mentioned technical problems, or at least partially solve the above-mentioned technical problems, this application provides a PFC circuit control method, device, frequency converter and storage medium.

[0004] In a first aspect, this application provides a PFC circuit control method, the method comprising:

[0005] When the power factor correction (PFC) circuit is in critical mode, determine the inductance value of the inductor in the PFC circuit.

[0006] The operation of the PFC circuit is controlled by adjusting the inductance value.

[0007] Optionally, determining the inductance value of the inductor in the PFC circuit when the PFC circuit is in critical mode includes:

[0008] When the PFC circuit is in critical conduction mode or turn-off mode, the inductance value of the inductor is determined according to the first correspondence between the input voltage and the inductor current of the PFC circuit, wherein the first correspondence indicates that the inductor current changes linearly with the change of the input voltage.

[0009] Optionally, controlling the operation of the PFC circuit by adjusting the inductance value includes:

[0010] Determine whether the inductance value falls within a first preset range, wherein the first preset range indicates that the inductance is within the working inductance range;

[0011] When the inductance value is within the first preset range, it is determined whether the switching frequency of the PFC circuit is within the second preset range, wherein the second preset range indicates that the switching frequency of the PFC circuit is within the working switching frequency range.

[0012] When the switching frequency is not within the second preset range, the operation of the PFC circuit is controlled by adjusting the inductance value.

[0013] Optionally, after determining whether the inductance value falls within a first preset range, the method further includes:

[0014] When the inductance value is not within the first preset range, the operation of the PFC circuit is controlled by adjusting the inductance of the inductor, wherein the inductor is an energy storage inductor with adjustable inductance.

[0015] Optionally, the operation of the PFC circuit is controlled by adjusting the inductance of the inductor, including:

[0016] The magnetic flux of the auxiliary winding of the inductor is determined by adjusting the winding current of the inductor.

[0017] The operation of the PFC circuit is controlled based on the second correspondence between the magnetic flux and the inductance value of the inductor, and the step of determining the inductance value of the inductor in the PFC circuit.

[0018] Optionally, controlling the operation of the PFC circuit by adjusting the inductance value when the switching frequency is not within the second preset range includes:

[0019] When the switching frequency is not within the second preset range, the operation of the PFC circuit is controlled by adjusting the inductance of the inductor.

[0020] Optionally, the inductor is an E-type inductor with adjustable inductance.

[0021] Secondly, this application provides a PFC circuit control device, comprising:

[0022] The determination module is used to determine the inductance value of the inductor in the PFC circuit when the power factor correction PFC circuit is in critical mode.

[0023] The first control module is used to control the operation of the PFC circuit by adjusting the inductance value.

[0024] Optionally, the determining module includes:

[0025] The first determining unit is configured to determine the inductance value of the inductor based on a first correspondence between the input voltage and the inductor current of the PFC circuit when the PFC circuit is in a critical conduction mode or a critical shutdown mode, wherein the first correspondence indicates that the inductor current changes linearly with the change of the input voltage.

[0026] Optionally, the first control module includes:

[0027] The second determining unit is used to determine whether the inductance value belongs to a first preset range, wherein the first preset range indicates that the inductance is within the working inductance range;

[0028] The third determining unit is used to determine whether the switching frequency of the PFC circuit is within a second preset range when the inductance value is within the first preset range, wherein the second preset range indicates that the switching frequency of the PFC circuit is within the working switching frequency range.

[0029] The first control unit is used to control the operation of the PFC circuit by adjusting the inductance value when the switching frequency is not within the second preset range.

[0030] Optionally, after the second determining unit determines whether the inductance value falls within a first preset range, the device further includes:

[0031] The second control module is used to control the operation of the PFC circuit by adjusting the inductance of the inductor when the inductance value is not within the first preset range, wherein the inductor is an energy storage inductor with adjustable inductance.

[0032] Optionally, the second control module includes:

[0033] The fourth determining unit is used to determine the auxiliary winding flux of the inductor by adjusting the winding current of the inductor;

[0034] The second control unit is used to control the operation of the PFC circuit based on the second correspondence between the magnetic flux and the inductance value of the inductor and the step of determining the inductance value of the inductor in the PFC circuit.

[0035] Optionally, the first control unit includes:

[0036] The control subunit is used to control the operation of the PFC circuit by adjusting the inductance of the inductor when the switching frequency is not within the second preset range.

[0037] Optionally, the inductor is an E-type inductor with adjustable inductance.

[0038] Thirdly, this application provides a frequency converter, including: a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus;

[0039] The memory is used to store computer programs;

[0040] The processor, when executing a computer program, implements the steps of the method described in the first aspect above.

[0041] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in the first aspect above.

[0042] Fifthly, embodiments of this application also provide a computer program product containing instructions that, when run on a computer, cause the computer to perform the steps of the method described in the first aspect.

[0043] Compared with related technologies, the technical solutions provided in this application have the following advantages:

[0044] The PFC circuit control method provided in this application determines the actual inductance value of the inductor in the PFC circuit when the PFC circuit is in critical mode. Based on the adjustment of the inductance value, the operation of the PFC circuit is controlled so that the PFC circuit operates within a suitable range in the critical mode at the highest voltage point and zero crossing point. This can improve the inductance loss and electromagnetic interference problems, thereby solving the technical problem of inductance loss and electromagnetic interference caused by the increase of grid harmonic current and rapid changes in voltage and current at the highest voltage point and zero crossing point in existing power factor correction circuits. Attached Figure Description

[0045] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0046] To more clearly illustrate the technical solutions in the embodiments of this application 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.

[0047] Figure 1 A schematic flowchart of a PFC circuit control method provided in an embodiment of this application;

[0048] Figure 2 This is a basic circuit diagram of PFC provided in a specific embodiment of the present invention;

[0049] Figure 3 This is the dual-E variable inductor structure provided in the embodiments of the present invention;

[0050] Figure 4 This is a detection and adjustment flowchart provided in an embodiment of the present invention;

[0051] Figure 5A schematic diagram of the structure of a PFC circuit control device provided in an embodiment of this application;

[0052] Figure 6 This is a schematic diagram of the structure of a frequency converter provided in an embodiment of this application. Detailed Implementation

[0053] 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.

[0054] Optionally, in this embodiment, the above-described PFC circuit control method can be applied to a hardware environment consisting of a terminal and a server. The server connects to the terminal via a network and can be used to provide services to the terminal or clients installed on the terminal. A database can be set up on the server or independently of the server to provide data storage services to the server.

[0055] The aforementioned network may include, but is not limited to, at least one of the following: wired network, wireless network. The aforementioned wired network may include, but is not limited to, at least one of the following: wide area network, metropolitan area network, local area network. The aforementioned wireless network may include, but is not limited to, at least one of the following: Wi-Fi (Wireless Fidelity), Bluetooth. The terminal is not limited to PC, mobile phone, tablet computer, etc.

[0056] The PFC circuit control method of this application embodiment can be executed by a server, a terminal, or both. Alternatively, the PFC circuit control method of this application embodiment can be executed by a client installed on the terminal.

[0057] Taking the PFC circuit control method in this embodiment being executed by a server as an example, Figure 1 This is a flowchart illustrating a PFC circuit control method provided in an embodiment of this application. Figure 1 As shown, the method includes the following steps:

[0058] Step S102: When the power factor correction (PFC) circuit is in critical mode, determine the inductance value of the inductor in the PFC circuit.

[0059] Power factor correction (PFC) circuits are technologies used to improve the power factor of electrical equipment. Power factor is the ratio of effective power to total power consumption, a parameter used to measure the electrical efficiency of equipment; a low power factor indicates low power efficiency. For example, ... Figure 2 As shown, Figure 2 This is a basic circuit diagram of PFC provided in a specific embodiment of the present invention.

[0060] In this embodiment, critical mode refers to the PFC circuit being in a critical on state or a critical off state, that is, the PFC circuit being in a state at the highest voltage point and the zero crossing point.

[0061] In specific implementation, step S102 includes: when the PFC circuit is in critical conduction mode or turn-off mode, determining the inductance value of the inductor according to the first correspondence between the input voltage and the inductor current of the PFC circuit, wherein the first correspondence indicates that the inductor current changes linearly with the change of the input voltage.

[0062] In an optional example of this embodiment, in the critical turn-on or turn-off mode of the PFC circuit, when the input voltage changes significantly, the switching frequency (i.e., the number of times the electronic component can be fully turned on and off per second) will also vary widely. Too low a switching frequency will generate noise, while too high a frequency will increase losses and cause instability in PFC control. By adjusting the PFC inductor, the switching frequency can be kept within a suitable range at the highest voltage point and zero-crossing point, improving inductor losses and reducing EMI issues caused by the switching transistor.

[0063] Step S104: Control the operation of the PFC circuit by adjusting the inductance value.

[0064] The PFC circuit control method provided in this application determines the actual inductance value of the inductor in the PFC circuit when the PFC circuit is in critical mode. Based on the adjustment of the inductance value, the operation of the PFC circuit is controlled so that the PFC circuit operates within a suitable range in the critical mode at the highest voltage point and zero crossing point. This can improve the inductance loss and electromagnetic interference problems, thereby solving the technical problem of inductance loss and electromagnetic interference caused by the increase of grid harmonic current and rapid changes in voltage and current at the highest voltage point and zero crossing point in existing power factor correction circuits.

[0065] This application embodiment provides a possible implementation method, and the above step S104 includes the following steps:

[0066] Step S201: Determine whether the inductance value belongs to the first preset range, wherein the first preset range indicates that the inductance is within the working inductance range;

[0067] Furthermore, when the inductance value is not within the first preset range, the operation of the PFC circuit is controlled by adjusting the inductance value of the inductor, wherein the inductor is an energy storage inductor with adjustable inductance value. In this embodiment, the current is reduced when the inductance value does not meet the operating range, and the inductance value is adjusted to ensure that it meets the inductor's operating range.

[0068] In this embodiment, a DC auxiliary winding type inductor is used, which only requires an auxiliary winding, a working winding, and a common magnetic core, resulting in lower costs; the main purpose here is to achieve inductance adjustment. Optionally, the inductor in this embodiment is preferably a double-E variable inductor. Figure 3 This is the dual-E variable inductor structure provided in this embodiment of the invention. The inductor in this embodiment can also be replaced with a dual-ring inductor.

[0069] Step S202: When the inductance value is within the first preset range, determine whether the switching frequency of the PFC circuit is within the second preset range, wherein the second preset range indicates that the switching frequency of the PFC circuit is within the working switching frequency range.

[0070] Step S203: When the switching frequency is not within the second preset range, the operation of the PFC circuit is controlled by adjusting the inductance value.

[0071] In specific implementation, step S203 includes: determining the magnetic flux of the auxiliary winding of the inductor by adjusting the winding current of the inductor; and controlling the operation of the PFC circuit according to the second correspondence between the magnetic flux and the inductance value of the inductor and the step of determining the inductance value of the inductor in the PFC circuit.

[0072] In this embodiment, when the switching frequency does not meet the second preset range, the next detection is performed to achieve real-time adjustment of the sensitivity.

[0073] In an optional embodiment of this case, Figure 4 This is a detection and adjustment flowchart provided in an embodiment of the present invention, such as... Figure 4 As shown, it includes the following steps:

[0074] Step S1: Detect the PFC input voltage, output voltage, and inductor current;

[0075] Step S2, PFC sensitivity conversion;

[0076] Step S3: Does the sensitivity conform to the device's operating range (i.e., the first preset range mentioned above)? If yes, proceed to step S4; if no, proceed to step S7.

[0077] Step S4, switch cycle detection;

[0078] Step S5, switching frequency conversion;

[0079] Step S6: Determine whether the switching frequency meets the predetermined range (i.e., the second preset range mentioned above); if yes, end; if no, proceed to step S7.

[0080] Further, step S8 is performed to adjust the magnetic flux of the auxiliary winding, and then the process returns to step S1.

[0081] The above embodiments provide a PFC control method based on adjustable inductance critical mode. By detecting the PFC inductance and switching cycle during operation, the magnetic flux of the auxiliary winding is adjusted, and the inductance is adjusted in real time to make the PFC inductance and switching frequency have a suitable matching relationship, thereby improving inductance loss and EMI problems caused by the switching transistor.

[0082] Optionally, the above detection and adjustment process can be triggered periodically, that is, adjusted in real time according to the unit's operating status after startup.

[0083] The present invention will be further described below with reference to a specific embodiment.

[0084] This invention addresses PFC control in a PFC circuit under critical conduction conditions, combining... Figure 2 The PFC basic circuit diagram shown depicts a linear change in inductor current during both the on and off phases of the switching transistor. The relationship during on-time is as follows:

[0085]

[0086] The relationship between the changes when the circuit is turned off is as follows:

[0087]

[0088] When turned off, V in V is the input voltage. out V is the output voltage. G With V d The voltage across the IGBT and fast recovery diode is generally negligible. in Let L be the PFC inductor current and L be its inductance. Therefore, we can know...

[0089]

[0090] Where V L The voltage across the inductor is used to determine the inductance value under the current operating conditions. This allows us to assess whether the inductance meets the device's required operating inductance range. If it does, we proceed to the next step of detecting the switching frequency. If it does not, we end the current adjustment process.

[0091] The switching frequency in the current state can be directly calculated from the switching cycle. By comparing the switching frequency with the set range, it can be determined whether the current frequency is too high or too low, thereby determining the adjustment of the inductor inductance. The software PFC switching cycle can be obtained from the PWM wave cycle emitted by the chip.

[0092] Furthermore, the relationship between inductance and magnetic flux (i.e., the second correspondence mentioned above) is as follows:

[0093]

[0094] L is calculated in the previous step. By adjusting the winding current i, that is, by supplying the auxiliary winding with an adjustable constant current source, the inductance of the auxiliary winding remains unchanged, and the magnetic flux generated by it changes, thereby affecting the inductance of the working winding.

[0095] Furthermore, combined Figure 3 The dual-E variable inductor structure shown allows control of the inductance value of the working winding by changing the magnetic flux generated by the auxiliary winding. According to Ohm's law for magnetic circuits, the magnetic flux is proportional to the winding current. By connecting an adjustable constant current source external to the auxiliary winding, this source determines the current output based on a comparison between the switching frequency and a set frequency range. When the switching frequency is too low, the output current of the adjustable constant current source is reduced to decrease the inductance value and increase the switching frequency, thereby reducing inductor losses and switching noise. When the switching frequency is too high, the output current of the adjustable constant current source is increased to increase the inductance value and decrease the frequency, reducing switching turn-off losses and improving the stability of PFC control and EMI. This achieves mutual adjustment between the switching frequency and the PFC inductance.

[0096] Through the above implementation steps, the embodiments of this application can realize the detection of PFC inductance and switching cycle under operating conditions, adjust the magnetic flux of the auxiliary winding by an adjustable constant current source, adjust the inductance in real time, realize the adjustment of PFC inductance and switching frequency, solve the inductance loss and EMI problems caused by excessively high or low switching frequency at the highest voltage point and zero crossing point of traditional non-adjustable PFC, improve the control effect of PFC circuit switching frequency and improve the EMI effect of PFC circuit critical mode.

[0097] Based on the PFC circuit control methods provided in the above embodiments, and based on the same inventive concept, this embodiment also provides a PFC circuit control device for implementing the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0098] Figure 5A schematic diagram of a PFC circuit control device provided in an embodiment of this application is shown below. Figure 5 As shown, the device includes: a determination module 50, used to determine the inductance value of the inductor in the PFC circuit when the power factor correction (PFC) circuit is in critical mode; and a first control module 52, connected to the determination module 50, used to control the operation of the PFC circuit by adjusting the inductance value.

[0099] Optionally, the determining module 50 includes: a first determining unit, used to determine the inductance value of the inductor based on a first correspondence between the input voltage and the inductor current of the PFC circuit when the PFC circuit is in a critical conduction mode or a turn-off mode, wherein the first correspondence indicates that the inductor current changes linearly with the change of the input voltage.

[0100] Optionally, the first control module 52 includes: a second determining unit, configured to determine whether the inductance value falls within a first preset range, wherein the first preset range indicates that the inductance is within the working inductance range; a third determining unit, configured to determine whether the switching frequency of the PFC circuit is within a second preset range when the inductance value is within the first preset range, wherein the second preset range indicates that the switching frequency of the PFC circuit is within the working switching frequency range; and a first control unit, configured to control the operation of the PFC circuit by adjusting the inductance value when the switching frequency is not within the second preset range.

[0101] Optionally, after the second determining unit determines whether the inductance value falls within the first preset range, the above device further includes: a second control module, used to control the operation of the PFC circuit by adjusting the inductance of the inductor when the inductance value is not within the first preset range, wherein the inductor is an energy storage inductor with adjustable inductance.

[0102] Optionally, the second control module 52 includes: a fourth determining unit, used to determine the magnetic flux of the auxiliary winding of the inductor by adjusting the winding current of the inductor; and a second control unit, used to control the operation of the PFC circuit according to the second correspondence between the magnetic flux and the inductance value of the inductor and the step of determining the inductance value of the inductor in the PFC circuit.

[0103] Optionally, the first control unit includes a control subunit, used to control the operation of the PFC circuit by adjusting the inductance of the inductor when the switching frequency is not within a second preset range.

[0104] Optionally, the inductor is an E-type inductor with adjustable inductance.

[0105] It should be noted that the above modules can be implemented by software or hardware. For the latter, they can be implemented in the following ways, but are not limited to: all the above modules are located in the same processor; or, the above modules are located in different processors in any combination.

[0106] like Figure 6 As shown in the figure, this application provides a frequency converter, including a processor 111, a communication interface 112, a memory 113, and a communication bus 114, wherein the processor 111, the communication interface 112, and the memory 113 communicate with each other through the communication bus 114.

[0107] Memory 113 is used to store computer programs;

[0108] In one embodiment of this application, the processor 111, when executing the program stored in the memory 113, implements the PFC circuit control method provided in any of the foregoing method embodiments.

[0109] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the PFC circuit control method provided in any of the foregoing method embodiments.

[0110] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0111] 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 PFC circuit control method, characterized in that, The method includes: When the power factor correction (PFC) circuit is in critical mode, the PFC input voltage, output voltage, and inductor current are detected, and the inductance value of the inductor in the PFC circuit is determined based on the PFC input voltage, output voltage, and inductor current. The operation of the PFC circuit is controlled by adjusting the inductance value; The step of controlling the operation of the PFC circuit by adjusting the inductance value includes: Determine whether the inductance value falls within a first preset range, wherein the first preset range indicates that the inductance is within the working inductance range; When the inductance value is not within the first preset range, the operation of the PFC circuit is controlled by adjusting the inductance of the inductor, wherein the inductor is an energy storage inductor with adjustable inductance. When the inductance value is within the first preset range, it is determined whether the switching frequency of the PFC circuit is within the second preset range, wherein the second preset range indicates that the switching frequency of the PFC circuit is within the working switching frequency range, and the switching frequency is calculated from the switching cycle; When the switching frequency is not within the second preset range, the operation of the PFC circuit is controlled by adjusting the inductance value; The inductance of the working winding is controlled by changing the magnetic flux generated by the auxiliary winding. According to Ohm's law for magnetic circuits, the magnetic flux is proportional to the winding current. An adjustable constant current source is connected to the auxiliary winding. This adjustable constant current source determines the current output based on a comparison between the switching frequency and the set frequency range. When the switching frequency is too low, the output current of the adjustable constant current source is reduced to decrease the inductance value and increase the switching frequency, thereby reducing inductance loss and switching noise. When the switching frequency is too high, the output current of the adjustable constant current source is increased to increase the inductance value and decrease the frequency. After adjusting the inductance value, the process returns to the step of detecting the input voltage, output voltage, and inductor current of the PFC circuit to achieve periodic real-time adjustment.

2. The method according to claim 1, characterized in that, Determining the inductance value of the inductor in the PFC circuit when the PFC circuit is in critical mode includes: When the PFC circuit is in critical conduction mode or turn-off mode, the inductance value of the inductor is determined according to the first correspondence between the input voltage and the inductor current of the PFC circuit, wherein the first correspondence indicates that the inductor current changes linearly with the change of the input voltage.

3. The method according to claim 1, characterized in that, The operation of the PFC circuit is controlled by adjusting the inductance of the inductor, including: The magnetic flux of the auxiliary winding of the inductor is determined by adjusting the winding current of the inductor. The operation of the PFC circuit is controlled based on the second correspondence between the magnetic flux and the inductance value of the inductor, and the step of determining the inductance value of the inductor in the PFC circuit.

4. The method according to claim 1, characterized in that, When the switching frequency is not within the second preset range, controlling the operation of the PFC circuit by adjusting the inductance value includes: When the switching frequency is not within the second preset range, the operation of the PFC circuit is controlled by adjusting the inductance of the inductor.

5. The method according to any one of claims 1-4, characterized in that, The inductor is an E-type inductor with adjustable inductance.

6. A PFC circuit control device, characterized in that, The device includes: The determination module is used to detect the PFC input voltage, output voltage and inductor current when the power factor correction (PFC) circuit is in critical mode, and determine the inductance value of the inductor in the PFC circuit based on the PFC input voltage, output voltage and inductor current. The first control module is used to control the operation of the PFC circuit by adjusting the inductance value; The step of controlling the operation of the PFC circuit by adjusting the inductance value includes: Determine whether the inductance value falls within a first preset range, wherein the first preset range indicates that the inductance is within the working inductance range; When the inductance value is not within the first preset range, the operation of the PFC circuit is controlled by adjusting the inductance of the inductor, wherein the inductor is an energy storage inductor with adjustable inductance. When the inductance value is within the first preset range, it is determined whether the switching frequency of the PFC circuit is within the second preset range, wherein the second preset range indicates that the switching frequency of the PFC circuit is within the working switching frequency range, and the switching frequency is calculated from the switching cycle; When the switching frequency is not within the second preset range, the operation of the PFC circuit is controlled by adjusting the inductance value; The inductance of the working winding is controlled by changing the magnetic flux generated by the auxiliary winding. According to Ohm's law for magnetic circuits, the magnetic flux is proportional to the winding current. An adjustable constant current source is connected to the auxiliary winding. This adjustable constant current source determines the current output based on a comparison between the switching frequency and the set frequency range. When the switching frequency is too low, the output current of the adjustable constant current source is reduced to decrease the inductance value and increase the switching frequency, thereby reducing inductance loss and switching noise. When the switching frequency is too high, the output current of the adjustable constant current source is increased to increase the inductance value and decrease the frequency. After adjusting the inductance value, the process returns to the step of detecting the input voltage, output voltage, and inductor current of the PFC circuit to achieve periodic real-time adjustment.

7. A frequency converter, characterized in that, include: The processor, communication interface, memory, and communication bus are connected, with the processor, communication interface, and memory communicating with each other via the communication bus. The memory is used to store computer programs; The processor, when executing a computer program, implements the steps of the method described in any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the method described in any one of claims 1-5.

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