Resonant frequency adjustment method, power supply, electronic device, and storage medium

Abstract

The embodiment of the present disclosure provides a resonant frequency adjustment method, a power supply, an electronic device and a storage medium, and relates to the technical field of resonant converter control. The method is applied to a power supply comprising an LLC resonant converter, and the method comprises the following steps: obtaining a current resonant frequency of the resonant converter; obtaining a resonant frequency deviation between the current resonant frequency and a preset resonant frequency; and in the case that the resonant frequency deviation exceeds a preset threshold range, adjusting a synchronous rectification dead time to change an equivalent impedance of the resonant converter, so that the current resonant frequency returns to the preset resonant frequency.

Description

Technical Field

[0001] This disclosure relates to the field of resonant converter control technology, and more specifically, to a resonant frequency adjustment method, a power supply, an electronic device, and a storage medium. Background Technology

[0002] Due to its inherent soft-switching characteristics, LLC resonant converters can effectively reduce switching losses and improve power supply efficiency and power density, and have been widely used in power supplies with high requirements for efficiency and stability, such as modularized and capacitive power supplies. The stability of the resonant frequency of the LLC resonant converter is crucial to ensuring its soft-switching operation.

[0003] However, in actual operation, the resonant frequency of the LLC resonant converter is prone to drift, leading to reduced power supply efficiency, increased losses in switching devices, and shortened power supply lifespan. Therefore, stabilizing the resonant frequency of the LLC resonant converter has become an urgent problem to be solved. Summary of the Invention

[0004] In view of this, this disclosure proposes a new technical solution for a resonant frequency adjustment method, a power supply, electronic equipment, and a storage medium.

[0005] According to a first aspect of this disclosure, a method for adjusting the resonant frequency is provided, applied to a power supply including an LLC resonant converter, the method comprising: Obtain the current resonant frequency of the resonant converter; Obtain the resonant frequency deviation between the current resonant frequency and the preset resonant frequency; If the resonant frequency deviation exceeds a preset threshold range, the synchronous rectification dead time is adjusted to change the equivalent impedance of the resonant converter, so that the current resonant frequency returns to the preset resonant frequency.

[0006] Optionally, adjusting the synchronous rectification dead time includes: Based on the resonant frequency deviation, determine the initial adjustment direction; Based on the initial adjustment direction, adjust the synchronous rectification dead time; The method further includes: After completing the current adjustment operation of the synchronous rectification dead time based on the initial adjustment direction, the target adjustment direction is determined; Based on the target adjustment direction, continue to execute the steps of obtaining the resonant frequency deviation and adjusting the synchronous rectification dead time until the resonant frequency deviation is within the preset threshold range.

[0007] Optionally, determining the initial adjustment direction based on the resonant frequency deviation includes: If the current resonant frequency is greater than the preset resonant frequency, the initial adjustment direction is determined to be to increase the synchronous rectification dead time; If the current resonant frequency is less than the preset resonant frequency, the initial adjustment direction is determined to be to reduce the synchronous rectification dead time.

[0008] Optionally, determining the target adjustment direction includes: Obtain the first resonant current and the second resonant current of the resonant converter, wherein the first resonant current is the resonant current before the current adjustment operation, and the second resonant current is the resonant current after the current adjustment operation; The target adjustment direction is determined based on the first resonant current and the second resonant current.

[0009] Optionally, determining the target adjustment direction based on the first resonant current and the second resonant current includes: When the second amplitude of the second resonant current is greater than the first amplitude of the first resonant current, the target adjustment direction is determined as the initial adjustment direction; and / or, If the second amplitude of the second resonant current is less than the first amplitude of the first resonant current, the target adjustment direction is determined to be the opposite direction of the initial adjustment direction.

[0010] Optionally, determining the target adjustment direction based on the first resonant current and the second resonant current includes: If the phase difference between the second phase of the second resonant current and the first phase of the first resonant current is less than a preset phase threshold, the target adjustment direction is determined as the initial adjustment direction; and / or, If the phase of the second phase of the second resonant current and the first phase of the first resonant current is greater than a preset phase threshold, the target adjustment direction is determined to be the opposite direction of the initial adjustment direction.

[0011] Optionally, obtaining the current resonant frequency of the resonant converter includes: Obtain the first resonant current of the resonant converter within a preset time period; The current resonant frequency is determined based on the zero-crossing interval of the first resonant current.

[0012] Optionally, obtaining the current resonant frequency of the resonant converter includes: Obtain the operating current of the power supply; When the operating current of the power supply is less than a preset current threshold, the current resonant frequency of the resonant converter is obtained.

[0013] According to a second aspect of this disclosure, a power supply is provided that performs the resonant frequency adjustment method as described in any one of the first aspects.

[0014] According to a third aspect of this disclosure, an electronic device is provided, comprising a memory and a processor, the memory being configured to store computer instructions, and the processor being configured to invoke the computer instructions from the memory to perform a resonant frequency adjustment method as described in any one of the first aspects.

[0015] According to a fourth aspect of this disclosure, a storage medium is provided that stores computer program instructions thereon, which, when executed by a processor, implement the resonant frequency adjustment method described in any one of the first aspects.

[0016] In this embodiment, when the resonant frequency deviation of the LLC resonant converter exceeds a preset threshold range, the equivalent impedance of the resonant converter is changed by adjusting the synchronous rectification dead time, thereby causing the resonant frequency of the resonant converter to return to the preset resonant frequency. The resonant frequency adjustment method of this embodiment can stabilize the resonant frequency of the resonant converter near the preset resonant frequency, thus solving a series of problems caused by resonant frequency drift.

[0017] Other features and advantages of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the present disclosure and, together with their description, serve to explain the principles of the present disclosure.

[0019] Figure 1 This is a schematic diagram of the power supply structure using the technical solutions provided in the embodiments of this disclosure; Figure 2 This is a schematic flowchart of a resonant frequency adjustment method provided according to an embodiment of the present disclosure; Figure 3 This is a schematic diagram of the structure of an electronic device provided according to an embodiment of the present disclosure. Detailed Implementation

[0020] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.

[0021] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use.

[0022] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0023] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0024] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0025] This disclosure relates to a technical solution for a resonant frequency adjustment method. This resonant frequency adjustment method is applied to a power supply containing an LLC resonant converter. This power supply can be a charge-formatting and grading power supply, a core piece of equipment in the lithium battery production process, primarily used for the formation and grading processes of lithium batteries.

[0026] Figure 1 This is a schematic diagram of the structure of a power supply that can apply the technical solutions provided in the embodiments of this disclosure. For example... Figure 1 As shown, the power supply 100 may include a front-end Buck-Boost (buck-boost) bidirectional converter 110 and a rear-end LLC resonant converter 120. The Buck-Boost bidirectional converter 110 is used to boost or buck the input voltage signal and output a voltage signal adapted to the LLC resonant converter 120. The LLC resonant converter 120 may include a primary-side half-bridge network 121, a resonant cavity 122, a transformer 123, an output rectifier bridge 124, a sampling module 125, and a control module 126. The primary-side half-bridge network 121 is used to chop the input voltage into a high-frequency square wave voltage to drive the rear-end resonant cavity 122. The resonant cavity 122 may be composed of a resonant inductor Lr and a resonant capacitor Cr. The theoretical formula for calculating the resonant frequency is... Where Lr is the resonant inductance value and Cr is the resonant capacitance value. Transformer 123 is used for electrical isolation and voltage transformation ratio (boost / buck). Output rectifier bridge 124 is used to convert a high-frequency sine wave into unidirectional pulsating DC. Sampling module 125 is used to acquire the resonant current of resonant cavity 122 in real time. Control module 126 outputs a control signal based on the resonant current to adjust the synchronous rectification dead time. This control signal can be, for example, a PWM signal. Output rectifier bridge 124 can be connected to a load; exemplarily, the output of LLC resonant converter 120 can be connected to a battery through a reverse connection protection circuit. The reverse connection protection circuit can include a unidirectional conducting element (such as a diode).

[0027] Due to its inherent soft-switching characteristics, the LLC resonant converter 120 can effectively reduce switching losses and improve power supply efficiency and power density. It has been widely used in power supplies with high requirements for efficiency and stability, such as modularized and capacitive power supplies. The stability of the resonant frequency of the LLC resonant converter is crucial to ensuring its soft-switching operation.

[0028] However, in actual operation, the resonant frequency of LLC resonant converters is prone to drift. This is especially true in applications involving batching and capacitive power supplies, where the batching process includes various operating modes such as constant current and constant voltage, and the load impedance range is extremely wide. When the power supply operating current is less than the preset current threshold (i.e., the power supply is under light load), the phenomenon of the resonant frequency deviating from the preset resonant frequency is particularly prominent.

[0029] In related technologies, the resonant frequency control of batch-capacitance power supplies often adopts a fixed frequency method. When the power supply is under light load operation, the switching frequency does not match the actual resonant frequency, which will disrupt the soft switching conditions, leading to an increase in the turn-off current of the switching transistor and an increase in the circulating current of the resonant cavity. This not only reduces the power supply's operating efficiency but also exacerbates the wear and tear of the switching devices and shortens the equipment's lifespan.

[0030] In related technologies, some resonant frequency tracking methods require additional complex detection circuits or cumbersome algorithms such as frequency scanning, which increases the cost of power supply equipment and hinders engineering implementation. Based on this, the present disclosure provides a resonant frequency adjustment method. By adjusting the synchronous rectification dead time of the output rectifier bridge, the equivalent impedance of the resonant converter is changed, thereby achieving adaptive adjustment of the resonant frequency. This eliminates the need for additional complex detection circuits or control circuits such as phase-locked loops and frequency scanning. Only a resonant current signal needs to be detected and the dead time adjusted, which simplifies the hardware structure, reduces equipment costs, and facilitates large-scale engineering applications.

[0031] Figure 2 This is a flowchart illustrating a resonant frequency adjustment method provided in an embodiment of this disclosure. This method is applied to a power supply containing an LLC resonant converter. Figure 2 As shown, the resonant frequency adjustment method may include the following steps.

[0032] Step S110: Obtain the current resonant frequency of the resonant converter.

[0033] Step S120: Obtain the resonant frequency deviation between the current resonant frequency and the preset resonant frequency.

[0034] Step S130: If the resonant frequency deviation exceeds the preset threshold range, adjust the synchronous rectification dead time.

[0035] In this embodiment of the disclosure, the current resonant frequency is the resonant frequency prior to the current adjustment operation of the synchronous rectification dead time. That is, the current resonant frequency is the resonant frequency prior to the adjustment operation in step S130.

[0036] The preset resonant frequency in this embodiment is a reference resonant frequency. This preset resonant frequency can be calculated based on the aforementioned theoretical formula for resonant frequency combined with the initial parameters of the resonant cavity, and determined after initial debugging.

[0037] In some examples, the resonant frequency deviation can be the difference between the current resonant frequency and the preset resonant frequency. In this example, the resonant frequency deviation is positive when the current resonant frequency is greater than the preset resonant frequency, and negative when the current resonant frequency is less than the preset resonant frequency. In this example, the preset threshold range is a range consisting of a minimum preset threshold and a maximum preset threshold. If the resonant frequency deviation is less than the minimum preset threshold or greater than the maximum preset threshold, it indicates that the resonant frequency deviation exceeds the preset threshold range.

[0038] In some examples, the resonant frequency deviation can be the absolute value of the difference between the current resonant frequency and the preset resonant frequency. In this example, exceeding the preset threshold range can be understood as the resonant frequency deviation being greater than the preset resonant frequency deviation value.

[0039] In this embodiment, the synchronous rectification dead time is the dead time of the secondary-side rectifier module (such as the output rectifier bridge 124) of the resonant converter. The synchronous rectification dead time refers to the brief time interval during which the upper and lower switches are simultaneously turned off during the switching process of the complementary switches in the rectifier module. Its function is to avoid shoot-through short circuits in the switches and reduce switching losses and electromagnetic interference. Improper dead time parameter matching can lead to increased output ripple and reduced efficiency, especially under light power supply load conditions, which can exacerbate frequency drift and operating point mismatch in the resonant converter.

[0040] The steps for adjusting the synchronous rectification dead time may include: increasing the synchronous rectification dead time when the resonant frequency is greater than the preset resonant frequency; and decreasing the synchronous rectification dead time when the resonant frequency is less than the preset resonant frequency.

[0041] In this embodiment of the disclosure, adjusting the synchronous rectification dead time can change the equivalent impedance of the resonant cavity in the resonant converter, so that the current resonant frequency returns to the preset resonant frequency.

[0042] In this embodiment, when the resonant frequency deviation of the LLC resonant converter exceeds a preset threshold range, the equivalent impedance of the resonant converter is changed by adjusting the synchronous rectification dead time, thereby causing the resonant frequency of the resonant converter to return to the preset resonant frequency. The resonant frequency adjustment method of this embodiment can stabilize the resonant frequency of the resonant converter near the preset resonant frequency, thus solving a series of problems caused by resonant frequency drift. Furthermore, there is no need to adjust the switching frequency of the primary-side switching transistor in real time; the primary-side switching transistor operates at a fixed frequency, simplifying EMI filtering design and facilitating parallel synchronization of multiple power supply modules.

[0043] In some embodiments of this disclosure, step S110 may include: obtaining the operating current of the power supply; and obtaining the current resonant frequency of the resonant converter when the operating current of the power supply is less than a preset current threshold.

[0044] The preset current threshold can be a preset percentage of the power supply's rated operating current, used to determine whether the power supply is under light load. For example, this preset percentage can be 10% to 30%.

[0045] When the power supply operating current is greater than or equal to the preset current threshold, the power supply is in normal operating condition, and the resonant frequency adaptive adjustment is not activated. When the power supply operating current is less than the preset current threshold, the resonant frequency adaptive adjustment is activated, and the resonant frequency detection and adjustment process begins. Using this method, the resonant frequency adaptive adjustment can be activated selectively under light load conditions, avoiding unnecessary adjustments under normal load conditions and improving the overall system operating efficiency.

[0046] In some embodiments of this disclosure, step S110 may include: obtaining the first resonant current of the resonant converter within a preset time period; and determining the current resonant frequency based on the zero-crossing time interval of the first resonant current.

[0047] In some examples, the sampling module can use a current sensor or shunt to periodically collect the resonant current of the resonant cavity according to a preset sampling period. After filtering and amplifying the collected resonant current signal, it is transmitted to the control module.

[0048] In some examples, filtering can be performed using a second-order low-pass filter circuit to eliminate high-frequency interference signals and ensure the accuracy of the sampled signal.

[0049] In some examples, the current resonant frequency is an approximation of the actual resonant frequency. In other examples, the zero-crossing interval of the resonant current is detected, and the reciprocal of this interval is taken as the current resonant frequency. This method is simple and easy to implement, requires no complex frequency detection hardware, and is highly reliable. The zero-crossing interval is the time interval between adjacent zero-crossing moments.

[0050] For step S120, exemplarily, the resonant frequency deviation can be calculated according to the formula... The calculation yielded the following result. For resonant frequency deviation, The current resonant frequency, The preset resonant frequency is used. If the resonant frequency deviation does not exceed the preset threshold range, the current dead time is maintained, and the process returns to step S110 to continue detection; if the resonant frequency deviation exceeds the preset threshold range, the process proceeds to step S130 to perform dead time adjustment.

[0051] In some embodiments of this disclosure, the step of adjusting the synchronous rectification dead time in step S130 may include: determining an initial adjustment direction based on the resonant frequency deviation; adjusting the synchronous rectification dead time based on the initial adjustment direction; determining a target adjustment direction after completing the current adjustment operation of the synchronous rectification dead time based on the initial adjustment direction; and continuing to execute the steps of obtaining the resonant frequency deviation and adjusting the synchronous rectification dead time based on the target adjustment direction until the resonant frequency deviation is within a preset threshold range.

[0052] This embodiment of the disclosure establishes a dual determination mechanism for the initial adjustment direction and the target adjustment direction. This allows for dynamic correction of the adjustment direction based on changes in the resonant current after each dead-time adjustment, achieving more precise closed-loop control and avoiding oscillation or divergence problems caused by incorrect adjustment direction. Especially in embodiments where the current resonant frequency is an approximation of the actual resonant frequency, the initial adjustment direction is based on the relationship between the approximation of the current actual resonant frequency and the reference resonant frequency. In this case, the initial adjustment direction may be incorrect. Re-determining the adjustment direction after the initial adjustment improves the accuracy of the adjustment.

[0053] In some embodiments of this disclosure, determining the initial adjustment direction based on the resonant frequency deviation may include: when the current resonant frequency is greater than a preset resonant frequency, determining the initial adjustment direction to increase the synchronous rectification dead time; when the current resonant frequency is less than a preset resonant frequency, determining the initial adjustment direction to decrease the synchronous rectification dead time.

[0054] This embodiment of the invention can change the equivalent operating state of the resonant cavity by adjusting the dead time of the output rectifier. Increasing the dead time causes the output rectifier to remain in the off state for a longer period, increasing the equivalent impedance of the resonant cavity during the non-conducting time and lowering the resonant frequency; decreasing the dead time decreases the equivalent impedance of the resonant cavity and increases the resonant frequency. This achieves a regression of the actual resonant frequency to the preset resonant frequency.

[0055] In some embodiments of this disclosure, determining the target adjustment direction may include: acquiring a first resonant current and a second resonant current of the resonant converter; and determining the target adjustment direction based on the first resonant current and the second resonant current.

[0056] In this embodiment of the present disclosure, the first resonant current is the resonant current before the current adjustment operation, and the second resonant current is the resonant current after the current adjustment operation.

[0057] In this embodiment of the present disclosure, the first resonant current and the second resonant current can be acquired by a sampling module, which respectively reflect the working state of the resonant cavity before and after the dead time adjustment.

[0058] This embodiment of the invention can determine whether the dead time adjustment causes the resonant frequency to change toward the preset resonant frequency by comparing the resonant current characteristics before and after adjustment, thereby dynamically determining the subsequent adjustment direction.

[0059] In some embodiments of this disclosure, determining the target adjustment direction based on the first resonant current and the second resonant current may include: determining the target adjustment direction based on the first amplitude of the first resonant current and the second amplitude of the second resonant current; and / or, determining the target adjustment direction based on the first phase of the first resonant current and the second phase of the second resonant current.

[0060] When the resonant current amplitude is at its maximum, the phase waveform distortion is at its minimum, and the zero-crossing interval is at its most stable, the current resonant frequency matches the preset resonant frequency, and the power supply operates in the optimal soft-switching state. If the resonant current amplitude decreases or the phase waveform shows significant distortion (such as spikes or waveform asymmetry), it indicates that the current resonant frequency deviates from the preset resonant frequency. Based on this, in some embodiments of this disclosure, determining the target adjustment direction based on the first and second resonant currents may include: determining the target adjustment direction as the initial adjustment direction when the second amplitude of the second resonant current is greater than the first amplitude of the first resonant current; and / or, determining the target adjustment direction as the opposite direction of the initial adjustment direction when the second amplitude of the second resonant current is less than the first amplitude of the first resonant current. That is, if the resonant current amplitude increases after dead-time adjustment, it indicates that the adjustment direction is correct, and adjustment should continue along the initial adjustment direction; if the resonant current amplitude decreases, it indicates that the adjustment direction is incorrect, and the adjustment direction needs to be reversed.

[0061] In some examples, the dead time adjustment step size can be preset, and if the initial adjustment direction is correct, the adjustment can continue according to this step size.

[0062] In some examples, if the initial adjustment direction is incorrect, the adjustment can be performed in the opposite direction using a time step smaller than the preset dead time.

[0063] The embodiments disclosed herein determine the target adjustment direction by comparing the amplitude of the resonant current before and after adjustment, which can effectively ensure that each dead time adjustment is performed in the direction of resonant frequency return.

[0064] In some embodiments of this disclosure, determining the target adjustment direction based on the first resonant current and the second resonant current may further include: determining the target adjustment direction as the initial adjustment direction when the phase difference between the second phase of the second resonant current and the first phase of the first resonant current is less than a preset phase threshold; and / or, determining the target adjustment direction as the opposite direction of the initial adjustment direction when the phase difference between the second phase of the second resonant current and the first phase of the first resonant current is greater than a preset phase threshold.

[0065] This embodiment of the invention determines whether the dead-time adjustment causes the resonant current phase to change in the desired direction by comparing the phase difference, thereby determining the subsequent adjustment direction. This provides another flexible and reliable method for direction determination, applicable to different circuit operating conditions. Through the above closed-loop iterative adjustment, a complete adaptive control flow is formed, consisting of dead-time adjustment, frequency change, current detection, direction determination, and closed-loop adjustment, achieving continuous tracking and dynamic adjustment of the resonant frequency.

[0066] In some embodiments of this disclosure, the resonant frequency adjustment method described above can be performed by a power supply. This power supply can be a formation and capacity testing power supply, suitable for lithium battery formation and capacity testing production scenarios. It can achieve adaptive adjustment of the resonant frequency under wide load and dynamic load conditions, ensuring high-efficiency operation during no-load and light-load processes, reducing device stress, and improving the lifespan of the power module.

[0067] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this disclosure. For example... Figure 3 As shown, the electronic device 300 may include a memory 310 and a processor 320. The memory 310 may be used to store computer instructions, and the processor 320 may be used to retrieve computer instructions from the memory 310 to execute the above-described resonant frequency adjustment method.

[0068] In some examples, processor 320 may be a central processing unit, microprocessor, digital signal processor, or other chip with data processing capabilities. Memory 310 may be a storage medium such as random access memory, read-only memory, or flash memory.

[0069] This disclosure also provides a storage medium storing computer program instructions, which, when executed by a processor, implement the aforementioned resonant frequency adjustment method. The storage medium may be a non-volatile computer-readable storage medium, such as a read-only memory, flash memory, hard disk, or optical disk.

[0070] This disclosure can be a system, method, and / or computer program product. A computer program product may include a computer-readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of this disclosure.

[0071] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by an instruction execution device. Computer-readable storage media can be, for example—but not limited to—electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of computer-readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination of the foregoing. The computer-readable storage media used herein are not to be construed as transient signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses through fiber optic cables), or electrical signals transmitted through wires.

[0072] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0073] Computer program instructions used to perform the operations of this disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, status setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may execute entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing the status information of the computer-readable program instructions to implement various aspects of this disclosure.

[0074] Various aspects of this disclosure are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0075] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that, when executed by the processor of the computer or other programmable data processing apparatus, they create means for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium that causes a computer, programmable data processing apparatus, and / or other device to operate in a particular manner; thus, the computer-readable medium storing the instructions comprises an article of manufacture that includes instructions for implementing aspects of the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0076] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to perform the functions / actions specified in one or more boxes of a flowchart and / or block diagram.

[0077] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of an instruction containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions. It will be known to those skilled in the art that implementation in hardware, implementation in software, and implementation in a combination of software and hardware are equivalent.

[0078] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein. The scope of this disclosure is defined by the appended claims.

Claims

1. A method for adjusting the resonant frequency, characterized in that, Applied to a power supply containing an LLC resonant converter, the method includes: Obtain the current resonant frequency of the resonant converter; Obtain the resonant frequency deviation between the current resonant frequency and the preset resonant frequency; If the resonant frequency deviation exceeds a preset threshold range, the synchronous rectification dead time is adjusted to change the equivalent impedance of the resonant converter, so that the current resonant frequency returns to the preset resonant frequency.

2. The method according to claim 1, characterized in that, The adjustment of the synchronous rectification dead time includes: Based on the resonant frequency deviation, determine the initial adjustment direction; Based on the initial adjustment direction, adjust the synchronous rectification dead time; The method further includes: After completing the current adjustment operation of the synchronous rectification dead time based on the initial adjustment direction, the target adjustment direction is determined; Based on the target adjustment direction, continue to execute the steps of obtaining the resonant frequency deviation and adjusting the synchronous rectification dead time until the resonant frequency deviation is within the preset threshold range.

3. The method according to claim 2, characterized in that, Determining the initial adjustment direction based on the resonant frequency deviation includes: If the current resonant frequency is greater than the preset resonant frequency, the initial adjustment direction is determined to be to increase the synchronous rectification dead time; If the current resonant frequency is less than the preset resonant frequency, the initial adjustment direction is determined to be to reduce the synchronous rectification dead time.

4. The method according to claim 2, characterized in that, The determination of the target adjustment direction includes: Obtain the first resonant current and the second resonant current of the resonant converter, wherein the first resonant current is the resonant current before the current adjustment operation, and the second resonant current is the resonant current after the current adjustment operation; The target adjustment direction is determined based on the first resonant current and the second resonant current.

5. The method according to claim 4, characterized in that, Determining the target adjustment direction based on the first resonant current and the second resonant current includes: When the second amplitude of the second resonant current is greater than the first amplitude of the first resonant current, the target adjustment direction is determined as the initial adjustment direction; and / or, If the second amplitude of the second resonant current is less than the first amplitude of the first resonant current, the target adjustment direction is determined to be the opposite direction of the initial adjustment direction.

6. The method according to claim 4, characterized in that, Determining the target adjustment direction based on the first resonant current and the second resonant current includes: If the phase difference between the second phase of the second resonant current and the first phase of the first resonant current is less than a preset phase threshold, the target adjustment direction is determined as the initial adjustment direction; and / or, If the phase of the second phase of the second resonant current and the first phase of the first resonant current is greater than a preset phase threshold, the target adjustment direction is determined to be the opposite direction of the initial adjustment direction.

7. The method according to claim 1, characterized in that, The step of obtaining the current resonant frequency of the resonant converter includes: Obtain the first resonant current of the resonant converter within a preset time period; The current resonant frequency is determined based on the zero-crossing interval of the first resonant current.

8. The method according to claim 1, characterized in that, The step of obtaining the current resonant frequency of the resonant converter includes: Obtain the operating current of the power supply; When the operating current of the power supply is less than a preset current threshold, the current resonant frequency of the resonant converter is obtained.

9. A power supply, characterized in that, Perform the resonant frequency adjustment method as described in any one of claims 1 to 8.

10. An electronic device, characterized in that, It includes a memory and a processor, the memory being used to store computer instructions, and the processor being used to retrieve the computer instructions from the memory to execute the resonant frequency adjustment method as described in any one of claims 1 to 8.

11. A storage medium storing computer program instructions thereon, characterized in that, When the computer program instructions are executed by the processor, they implement the resonant frequency adjustment method according to any one of claims 1 to 8.

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