Rapid voltage regulation method and system for LLC resonant converter
By controlling the output voltage of the LLC resonant converter in closed loop, combining frequency adjustment and switching of the parallel resistor branch, the voltage regulation problem of the LLC resonant converter in light load or no load is solved, and rapid voltage regulation and efficiency improvement are achieved.
Patent Information
- Application Number
- CN202510911187.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-02
- Publication Date
- 2025-08-08
AI Technical Summary
When LLC resonant converters are light or no-load, the equivalent impedance of the resonant network increases, the resonant current decreases, the energy transmission efficiency decreases, and the output voltage increases. In traditional methods, fixed dead loads lead to continuous energy consumption and reduced efficiency.
The output voltage of the LLC resonant converter is controlled by closed loop, and the frequency adjustment and switching of the parallel resistor branch are combined, the load is dynamically adjusted, and excess energy is consumed to avoid continuous loss of fixed dead load.
The LLC resonant converter is rapidly regulated during light load or no load, reducing the voltage regulation loss, improving efficiency, and avoiding the continuous energy consumption caused by dead load in traditional methods.
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Figure CN120454493A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the field of power electronics technology, and more specifically, relates to a method and system for fast voltage regulation of an LLC resonant converter. Background Art
[0002] The LLC resonant converter achieves zero voltage switching (ZVS) of the switching transistor through a resonant network, thereby reducing switching losses and improving efficiency. When the LLC resonant converter is lightly loaded or unloaded, the equivalent load impedance increases, the magnetizing inductance becomes more prominent, the equivalent impedance of the resonant network increases, the resonant current decreases, and the energy transmission efficiency decreases. However, the input energy remains unchanged, and the excess energy cannot be absorbed by the load, resulting in an increase in the output voltage.
[0003] To avoid these problems, the traditional solution is to set a fixed dead load at the output of the LLC resonant converter. However, this fixed dead load continuously consumes energy, resulting in reduced efficiency. Therefore, a low-loss LLC resonant converter voltage regulation method is urgently needed. Summary of the Invention
[0004] The purpose of the present application is to provide a method and system for fast voltage regulation of an LLC resonant converter, so as to reduce the voltage regulation loss of the LLC resonant converter when it is lightly loaded or no-loaded.
[0005] According to a first aspect of an embodiment of the present application, a method for rapid voltage regulation of an LLC resonant converter is provided, which is applied to an LLC resonant converter rapid voltage regulation system. The LLC resonant converter rapid voltage regulation system includes an LLC resonant converter, a parallel resistance branch, and a controller. Each resistance branch in the parallel resistance branch is provided with a first switching tube. Each resistance branch is connected in parallel to the output end of the LLC resonant converter through its corresponding first switching tube. The control end of the LLC resonant converter and the control end of the first switching tube are both communicatively connected to the controller. The method is executed by the controller and includes: Performing closed-loop control based on the output voltage of the LLC resonant converter to obtain a frequency of a control signal of the LLC resonant converter; In response to the frequency of the control signal of the LLC resonant converter being greater than a first frequency threshold and the output voltage of the LLC resonant converter being greater than a first voltage threshold, controlling the control signal of the LLC resonant converter to be turned off; selecting a first target resistance branch from the parallel resistance branches based on the frequency of the control signal of the LLC resonant converter, and controlling a first switch in the first target resistance branch to be closed, so as to connect the first target resistance branch in parallel to the output end of the LLC resonant converter; In response to the frequency of the control signal of the LLC resonant converter being less than or equal to a first frequency threshold, all first switch tubes in the parallel resistance branch are controlled to be turned off; and the output voltage of the LLC resonant converter is controlled based on the control signal of the LLC resonant converter.
[0006] According to a second aspect of an embodiment of the present application, a fast voltage regulation system for an LLC resonant converter is provided, comprising an LLC resonant converter, a parallel resistance branch and a controller, wherein each resistance branch in the parallel resistance branch is provided with a first switching tube, and each resistance branch is connected in parallel to the output end of the LLC resonant converter through its corresponding first switching tube, and the control end of the LLC resonant converter and the control end of the first switching tube are both communicatively connected to the controller, and the controller is configured to execute the steps of the above-mentioned method for fast voltage regulation of the LLC resonant converter.
[0007] According to a third aspect of an embodiment of the present application, a controller is provided, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein when the processor executes the computer program, the steps of the above-mentioned LLC resonant converter fast voltage regulation method are implemented.
[0008] According to a fourth aspect of the embodiments of the present application, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above-mentioned LLC resonant converter fast voltage regulation method are implemented.
[0009] The LLC resonant converter fast voltage regulation method and system provided by the embodiments of the present application have the following beneficial effects: The embodiment of the present application first performs closed-loop control based on the output voltage of the LLC resonant converter, adjusts the frequency of the control signal of the LLC resonant converter, and realizes preliminary adjustment of the output voltage through frequency adjustment. When the frequency of the control signal of the LLC resonant converter is greater than the first frequency threshold, it indicates that the frequency adjustment has reached the upper limit value. If the output voltage of the LLC resonant converter is still high at this time, that is, the output voltage of the LLC resonant converter is greater than the first voltage threshold, the frequency adjustment method is no longer used to adjust the output voltage of the LLC resonant converter. Instead, a first target resistance branch is selected from the parallel resistance branch, and the first target resistance branch is connected in parallel to the output end of the LLC resonant converter. The first target resistance branch can form an additional load path, consume the excess energy of the LLC resonant converter, and effectively suppress the problem of voltage increase of the LLC resonant converter when it is lightly loaded or no-loaded.
[0010] As the output voltage decreases, the frequency of the control signal of the LLC resonant converter continues to decrease. When the frequency of the control signal of the LLC resonant converter drops to less than or equal to the first frequency threshold, the connection between the first target resistance branch and the output end of the LLC resonant converter can be disconnected, and the frequency adjustment method can be used again to achieve the adjustment of the output voltage of the LLC resonant converter.
[0011] Therefore, the embodiment of the present application combines the frequency regulation method with the method of controlling the switching of the first target resistance branch, which can avoid the continuous loss of the traditional fixed dead load and is beneficial to reducing the voltage regulation loss of the LLC resonant converter at light load or no load. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0013] Figure 1 A schematic diagram of a fast voltage regulation system for an LLC resonant converter provided in one embodiment of the present application; Figure 2 A schematic flow chart of a method for rapid voltage regulation of an LLC resonant converter provided in one embodiment of the present application; Figure 3 A graph showing the relationship between the frequency of a control signal and the output voltage gain of an LLC resonant converter provided in one embodiment of the present application; Figure 4 A schematic block diagram of a controller provided in one embodiment of the present application; In the picture: 1-first switching tube, 2-second switching tube. DETAILED DESCRIPTION
[0014] In the following description, specific details such as specific system structures and techniques are provided for purposes of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present application with unnecessary detail.
[0015] In order to make the purpose, technical solutions and advantages of this application clearer, specific embodiments will be described below with reference to the accompanying drawings.
[0016] Please refer to Figure 1 , Figure 1A schematic diagram of an LLC resonant converter fast voltage regulation system provided in an embodiment of the present application, wherein the LLC resonant converter fast voltage regulation system includes an LLC resonant converter, a parallel resistance branch and a controller, wherein each resistance branch in the parallel resistance branch is provided with a first switching tube, and each resistance branch is connected in parallel to the output end of the LLC resonant converter through its respective corresponding first switching tube, and the control end of the LLC resonant converter and the control end of the first switching tube are both communicatively connected to the controller.
[0017] Furthermore, the LLC resonant converter fast voltage regulation method provided in the embodiment of the present application can be Figure 1 For controller execution in Figure 2 , Figure 2 This is a flow chart of a method for fast voltage regulation of an LLC resonant converter provided in one embodiment of the present application. The method may include: S101: Performing closed-loop control based on the output voltage of the LLC resonant converter to obtain the frequency of the control signal of the LLC resonant converter.
[0018] In this embodiment, closed-loop control can be first performed based on the output voltage of the LLC resonant converter to adjust the frequency of the control signal of the LLC resonant converter, that is, the frequency of the control signal of the resonant converter is determined based on the difference between the output voltage of the LLC resonant converter and the reference voltage, so as to achieve preliminary adjustment of the output voltage through frequency adjustment.
[0019] Specifically, a second switching tube is provided in the LLC resonant converter, and the control end of the second switching tube is the control end of the LLC resonant converter. By adjusting the frequency of the control signal of the LLC resonant converter, the operating frequency of the second switching tube can be adjusted, thereby adjusting the output voltage of the LLC resonant converter.
[0020] Please refer to Figure 3 , Figure 3 This is a relationship diagram between the frequency of the control signal and the output voltage gain of the LLC resonant converter provided in one embodiment of the present application. Figure 3 The horizontal axis represents the ratio of the LLC resonant converter's control signal frequency to its resonant frequency (Fx), while the vertical axis represents the voltage gain. The LLC resonant converter operates in the inductive region, to the right of Fx = 1. In this region, the higher the control signal frequency, the lower the LLC resonant converter's output voltage. Therefore, when the LLC resonant converter's output voltage increases, the output voltage can be reduced by increasing the control signal frequency.
[0021] S102: In response to the frequency of the control signal of the LLC resonant converter being greater than a first frequency threshold and the output voltage of the LLC resonant converter being greater than a first voltage threshold, controlling the control signal of the LLC resonant converter to be turned off; selecting a first target resistance branch from the parallel resistance branch based on the frequency of the control signal of the LLC resonant converter, and controlling the first switch tube in the first target resistance branch to be closed, so as to connect the first target resistance branch in parallel to the output end of the LLC resonant converter.
[0022] In this embodiment, when the frequency of the control signal of the LLC resonant converter is greater than the first frequency threshold, it indicates that the frequency adjustment has reached the upper limit. If the output voltage of the LLC resonant converter is still high at this time, that is, the output voltage of the LLC resonant converter is greater than the first voltage threshold, the control signal of the LLC resonant converter is controlled to be turned off, and a first target resistance branch is selected from the parallel resistance branch based on the frequency of the control signal of the LLC resonant converter. The first switch tube in the first target resistance branch is controlled to be closed to connect the first target resistance branch in parallel to the output end of the LLC resonant converter. The first target resistance branch can form an additional load path, consume excess energy of the LLC resonant converter, achieve rapid adjustment of the output voltage, and effectively suppress the problem of voltage increase of the LLC resonant converter when it is lightly loaded or no-loaded. Wherein, the first frequency threshold and the first voltage threshold are both preset constants. For example, the first frequency threshold can be 350KHz, and the first voltage threshold can be 1.05 times the reference voltage Vref.
[0023] Specifically, the higher the frequency of the control signal of the LLC resonant converter, the higher the resistance of the resistance branch that needs to be switched, and accordingly the first target resistance branch can be selected.
[0024] S103: In response to the frequency of the control signal of the LLC resonant converter being less than or equal to the first frequency threshold, controlling all first switch tubes in the parallel resistance branch to be turned off; and controlling the output voltage of the LLC resonant converter based on the control signal of the LLC resonant converter.
[0025] In this embodiment, as the output voltage decreases, the difference between the output voltage and the reference voltage decreases, and the frequency of the control signal of the LLC resonant converter continues to decrease. When the frequency of the control signal of the LLC resonant converter drops to less than or equal to a first frequency threshold, the connection between the first target resistance branch and the output end of the LLC resonant converter can be disconnected, and the output voltage of the LLC resonant converter can be adjusted again using the frequency adjustment method. Compared with the switching resistor method, the frequency adjustment method can achieve fine adjustment of the output voltage of the LLC resonant converter.
[0026] From the above, it can be concluded that this embodiment first performs closed-loop control based on the output voltage of the LLC resonant converter, adjusts the frequency of the control signal of the LLC resonant converter, and achieves preliminary adjustment of the output voltage through frequency adjustment. When the frequency of the control signal of the LLC resonant converter is greater than the first frequency threshold, it indicates that the frequency adjustment has reached the upper limit value. If the output voltage of the LLC resonant converter is still high at this time, that is, the output voltage of the LLC resonant converter is greater than the first voltage threshold, the frequency adjustment method is no longer used to adjust the output voltage of the LLC resonant converter. Instead, a first target resistance branch is selected from the parallel resistance branch and the first target resistance branch is connected in parallel to the output end of the LLC resonant converter. The first target resistance branch can form an additional load path, consume excess energy of the LLC resonant converter, and effectively suppress the problem of voltage increase of the LLC resonant converter when it is lightly loaded or no-loaded.
[0027] As the output voltage decreases, the frequency of the control signal of the LLC resonant converter continues to decrease. When the frequency of the control signal of the LLC resonant converter drops to less than or equal to the first frequency threshold, the connection between the first target resistance branch and the output end of the LLC resonant converter can be disconnected, and the frequency adjustment method can be used again to achieve the adjustment of the output voltage of the LLC resonant converter.
[0028] Therefore, the embodiment of the present application combines the frequency regulation method and the parallel resistance branch switching method to achieve rapid regulation of the output voltage of the LLC resonant converter. At the same time, it avoids the continuous loss of the traditional fixed dead load, which is beneficial to reducing the voltage regulation loss of the LLC resonant converter when it is lightly loaded or no-loaded.
[0029] In one embodiment of the present application, each resistance branch in the parallel resistance branch has the same resistance value; and selecting a first target resistance branch from the parallel resistance branch based on the frequency of the control signal of the LLC resonant converter includes: determining a first target quantity based on a frequency of a control signal of the LLC resonant converter; A first target resistance branch is selected from the parallel resistance branches based on the first target number.
[0030] In this embodiment, the frequency of the control signal of the LLC resonant converter is obtained by closed-loop control of the output voltage. Therefore, the higher the frequency of the control signal of the LLC resonant converter, the greater the difference between the output voltage of the LLC resonant converter and the reference voltage. At this time, a larger load is required to consume excess energy of the LLC resonant converter and achieve regulation of the output voltage of the LLC resonant converter.
[0031] Specifically, each resistance branch in the parallel resistance branch can be set to have the same resistance value. Based on this, a first target number is determined based on the frequency of the control signal of the LLC resonant converter. The higher the frequency of the LLC resonant converter's control signal, the larger the first target number. The first target number of resistance branches (i.e., first target resistance branches) is then connected in parallel to the output end of the LLC resonant converter. This embodiment adjusts the equivalent load size by controlling the number of closed resistance branches, thereby simplifying the control of the parallel resistance branches.
[0032] In one embodiment of the present application, selecting a first target resistance branch from a parallel resistance branch based on a first target number can be described in detail as follows: randomly selecting a first target number of resistance branches from the parallel resistance branch as the first target resistance branch; or, pre-numbering multiple resistance branches in the parallel resistance branch (for example, 1, 2, 3, ...), and selecting a first target number of resistance branches from the parallel resistance branch as the first target resistance branch in order of the numbers; or, sorting multiple resistance branches in the parallel resistance branch according to the cumulative value of the number of closures, the larger the cumulative value of the number of closures, the lower the sorting, and on this basis, selecting a first target number of resistance branches from the parallel resistance branch as the first target resistance branch in order of the cumulative value of the number of closures from small to large, and preferentially selecting a resistance branch with a smaller cumulative value of the number of closures as the first target resistance branch, thereby avoiding the problem of uneven usage frequency of multiple resistance branches, and avoiding premature aging of a single branch due to frequent opening and closing, which affects the rapid voltage regulation of the LLC resonant converter.
[0033] In one embodiment of the present application, determining the first target quantity based on the frequency of the control signal of the LLC resonant converter includes: In response to a frequency of a control signal of the LLC resonant converter being between a first frequency threshold and a second frequency threshold, setting the first target amount to a first amount; In response to a frequency of a control signal of the LLC resonant converter being between a second frequency threshold and a third frequency threshold, setting the first target amount to a second amount; Among them, the first frequency threshold, the second frequency threshold and the third frequency threshold increase in sequence, and the first number is smaller than the second number.
[0034] In this embodiment, the operating frequency range of the LLC resonant converter can be segmented, with each segment corresponding to a set number of resistance branches. Taking two segments as an example, when the operating frequency of the LLC resonant converter is in the first segment (between the first frequency threshold and the second frequency threshold), the first target number is set to a smaller first number; when the operating frequency of the LLC resonant converter is in the second segment (between the second frequency threshold and the third frequency threshold), the first target number is set to a larger second number.
[0035] Taking four segments as an example, assuming that the operating frequency range of the LLC resonant converter is 350KHz~450KHz, one IGBT can be turned on when the operating frequency of the LLC resonant converter is 350KHz-362.5KHz, two IGBTs can be turned on when the operating frequency of the LLC resonant converter is 362.5KHz-375KHz, three IGBTs can be turned on when the operating frequency of the LLC resonant converter is 375KHz-387.5KHz, and four IGBTs can be turned on when the operating frequency of the LLC resonant converter is 387.5KHz-400KHz.
[0036] From the above, it can be concluded that this embodiment determines the number of resistance branches that need to be closed (switched) based on the operating frequency of the LLC resonant converter, which can realize load switching according to actual needs. While ensuring light-load stability and dynamic response capability, the efficiency of the LLC converter can be improved. The method is simple, reliable, and cost-effective.
[0037] In one embodiment of the present application, before performing closed-loop control based on the output voltage of the LLC resonant converter, the LLC resonant converter fast voltage regulation method further includes: Obtain load current in real time and calculate the rate of change of load current; Selecting a second target resistance branch from the parallel resistance branches based on the rate of change of the load current; The first switch tube in the second target resistance branch is controlled to be closed.
[0038] In this embodiment, considering that the voltage increase of the LLC resonant converter when it is lightly loaded or unloaded is mainly caused by the rapid decrease of the load current, a "pre-switching" logic can be added to predict the number of resistance branches to be connected according to the load current change rate, and take action in advance to suppress voltage overshoot.
[0039] In one embodiment of the present application, each resistance branch in the parallel resistance branch has the same resistance value; and selecting a second target resistance branch from the parallel resistance branches based on a rate of change of the load current includes: determining a second target quantity based on a rate of change of the load current; A second target resistance branch is selected from the parallel resistance branches based on the second target number.
[0040] In this embodiment, a method similar to that of the previous embodiment can be used to determine a second target number based on the rate of change of the load current. The second target number of resistor branches (i.e., second target resistor branches) can be connected in parallel at the output of the LLC resonant converter to achieve rapid output voltage regulation. A greater rate of change of the load current indicates a higher output voltage, and a greater second target number is required.
[0041] In one embodiment of the present application, selecting a first target resistance branch from the parallel resistance branches based on a first target number includes: If the first target number is less than the second target number, selecting a third target resistance branch from the second target resistance branch based on the first target number, and determining the third target resistance branch as the first target resistance branch; If the first target number is equal to the second target number, determining the second target resistance branch as the first target resistance branch; If the first target number is greater than the second target number, a third target number is determined based on the difference between the first target number and the second target number, a fourth target resistance branch is selected from the unselected resistance branches based on the third target number, and the fourth target resistance branch and the second target resistance branch are determined as the first target resistance branch.
[0042] In this embodiment, in order to reduce the repeated closing or closing of the resistance branch, when controlling the closing of the first target number of resistance branches, if the second target number of resistance branches are already closed at this time, the corresponding resistance branch can be selected as the first target resistance branch based on the relative size of the first target number and the second target number.
[0043] Specifically, if the first target quantity is less than the second target quantity, the first target quantity of resistance branches can be selected from the second target resistance branch as the first target resistance branch, and the resistance branches other than the first target resistance branch in the second target resistance branch are disconnected; if the first target quantity is equal to the second target quantity, the second target resistance branch is determined as the first target resistance branch; if the first target quantity is greater than the second target quantity, the difference between the first target quantity and the second target quantity is used as the third target quantity, and based on the third target quantity, the fourth target resistance branch is selected from the resistance branch that has not been selected, and the fourth target resistance branch and the second target resistance branch are determined as the first target resistance branch.
[0044] It can be concluded from the above that, in this embodiment, the first target resistance branch is determined based on the relative sizes of the first target quantity and the second target quantity, which can avoid repeated closing or closing of the resistance branch.
[0045] In one embodiment of the present application, closed-loop control is performed based on the output voltage of the LLC resonant converter, including: The PI control method is used to perform closed-loop control on the output voltage of the LLC resonant converter.
[0046] In this embodiment, a PI control method can be used to perform closed-loop control on the output voltage of the LLC resonant converter. Specifically, the difference between the output voltage and the reference voltage can be input into the PI controller, and the PI controller outputs the frequency of the control signal of the LLC resonant converter.
[0047] Corresponding to the LLC resonant converter fast voltage regulation method of the above embodiment, an embodiment of the present application provides an LLC resonant converter fast voltage regulation system, including an LLC resonant converter, a parallel resistance branch and a controller, each resistance branch in the parallel resistance branch is provided with a first switching tube, each resistance branch is connected in parallel to the output end of the LLC resonant converter through its corresponding first switching tube, the control end of the LLC resonant converter and the control end of the first switching tube are both communicated with the controller, and the controller is configured to execute the steps of the above-mentioned LLC resonant converter fast voltage regulation method.
[0048] See also Figure 4 , Figure 4 This is a schematic block diagram of a controller provided in one embodiment of the present application. Figure 4 The controller 300 in this embodiment may include one or more processors 301, one or more input devices 302, one or more output devices 303, and one or more memories 304. The processors 301, input devices 302, output devices 303, and memories 304 communicate with each other via a communication bus 305. The memory 304 is used to store computer programs, which include program instructions. The processor 301 is configured to execute the program instructions stored in the memory 304. The processor 301 is configured to execute the steps of the above-described LLC resonant converter rapid voltage regulation method.
[0049] It should be understood that in the embodiment of the present application, the processor 301 may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc.
[0050] The input device 302 may include a touchpad, a fingerprint collection sensor (for collecting user fingerprint information and fingerprint direction information), a microphone, etc. The output device 303 may include a display (LCD, etc.), a speaker, etc.
[0051] The memory 304 may include a read-only memory and a random access memory, and provides instructions and data to the processor 301. A portion of the memory 304 may also include a non-volatile random access memory. For example, the memory 304 may also store preset constants such as a first frequency threshold, a second frequency threshold, a third frequency threshold, and a first voltage threshold.
[0052] In a specific implementation, the processor 301, input device 302, and output device 303 described in the embodiment of the present application can execute the implementation method described in the LLC resonant converter fast voltage regulation method provided in the embodiment of the present application, and can also execute the implementation method of the controller described in the embodiment of the present application, which will not be repeated here.
[0053] In another embodiment of the present application, a computer-readable storage medium is provided. The computer-readable storage medium stores a computer program. The computer program includes program instructions. When the program instructions are executed by a processor, all or part of the process of the method in the above embodiment is implemented. The computer program can also be used to instruct related hardware to complete the process. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of each of the above method embodiments are implemented. The computer program includes computer program code, which can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium.
[0054] The computer-readable storage medium can be the internal storage unit of the controller in any of the aforementioned embodiments, such as the controller's hard drive or memory. The computer-readable storage medium can also be an external storage device of the controller, such as a plug-in hard drive, a Smart Media Card (SMC), a Secure Digital (SD) card, a flash memory card, etc. Furthermore, the computer-readable storage medium can include both the controller's internal storage unit and an external storage device. The computer-readable storage medium is used to store computer programs and other programs and data required by the controller. The computer-readable storage medium can also be used to temporarily store data that has been output or is about to be output.
[0055] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.
[0056] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the controller and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.
[0057] In the several embodiments provided in this application, it should be understood that the disclosed controller and method can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods, such as modules can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces or units, or can be an electrical, mechanical or other form of connection.
[0058] The units described as separate components may or may not be physically separate, and 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 units may be selected according to actual needs to achieve the purpose of the embodiments of the present application.
[0059] In addition, the functional modules in the various embodiments of the present application may be integrated into a processing module, or each module may exist physically separately, or two or more modules may be integrated into a single module. The above-mentioned integrated modules may be implemented in the form of hardware or software functional modules.
[0060] The above are only specific embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and such modifications or substitutions should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.
Claims
1. A method for fast voltage regulation of an LLC resonant converter, characterized in that: The invention is applied to an LLC resonant converter fast voltage regulation system, the LLC resonant converter fast voltage regulation system comprising an LLC resonant converter, a parallel resistance branch and a controller, each resistance branch in the parallel resistance branch is provided with a first switching tube, each resistance branch is connected in parallel to the output end of the LLC resonant converter through its corresponding first switching tube, a control end of the LLC resonant converter and a control end of the first switching tube are both communicatively connected to the controller, and the method is executed by the controller, the method comprising: Performing closed-loop control based on the output voltage of the LLC resonant converter to obtain a frequency of a control signal of the LLC resonant converter; In response to the frequency of the control signal of the LLC resonant converter being greater than a first frequency threshold and the output voltage of the LLC resonant converter being greater than a first voltage threshold, controlling the control signal of the LLC resonant converter to be turned off; selecting a first target resistance branch from the parallel resistance branches based on the frequency of the control signal of the LLC resonant converter, and controlling a first switch in the first target resistance branch to be closed, so as to connect the first target resistance branch in parallel to the output end of the LLC resonant converter; In response to the frequency of the control signal of the LLC resonant converter being less than or equal to a first frequency threshold, all first switch tubes in the parallel resistance branch are controlled to be turned off; and the output voltage of the LLC resonant converter is controlled based on the control signal of the LLC resonant converter.
2. The LLC resonant converter fast voltage regulation method according to claim 1, wherein: Each resistance branch in the parallel resistance branch has the same resistance value; and selecting a first target resistance branch from the parallel resistance branches based on the frequency of the control signal of the LLC resonant converter includes: determining a first target quantity based on a frequency of a control signal of the LLC resonant converter; A first target resistance branch is selected from the parallel resistance branches based on the first target number.
3. The LLC resonant converter fast voltage regulation method according to claim 2, wherein: The determining a first target quantity based on the frequency of the control signal of the LLC resonant converter includes: In response to a frequency of a control signal of the LLC resonant converter being between a first frequency threshold and a second frequency threshold, setting the first target amount to a first amount; In response to a frequency of a control signal of the LLC resonant converter being between a second frequency threshold and a third frequency threshold, setting the first target amount to a second amount; The first frequency threshold, the second frequency threshold, and the third frequency threshold increase sequentially, and the first number is smaller than the second number.
4. The LLC resonant converter fast voltage regulation method according to claim 2, wherein: Before performing closed-loop control based on the output voltage of the LLC resonant converter, the LLC resonant converter fast voltage regulation method further includes: Obtain load current in real time and calculate the rate of change of load current; Selecting a second target resistance branch from the parallel resistance branches based on the rate of change of the load current; The first switch tube in the second target resistance branch is controlled to be closed.
5. The LLC resonant converter fast voltage regulation method according to claim 4, wherein: Each resistance branch in the parallel resistance branch has the same resistance value; and selecting a second target resistance branch from the parallel resistance branches based on the rate of change of the load current includes: determining a second target quantity based on a rate of change of the load current; A second target resistance branch is selected from the parallel resistance branches based on the second target number.
6. The LLC resonant converter fast voltage regulation method according to claim 5, wherein: The selecting a first target resistance branch from the parallel resistance branches based on the first target number includes: If the first target number is less than the second target number, selecting a third target resistance branch from the second target resistance branch based on the first target number, and determining the third target resistance branch as the first target resistance branch; If the first target number is equal to the second target number, determining the second target resistance branch as the first target resistance branch; If the first target quantity is greater than the second target quantity, a third target quantity is determined based on the difference between the first target quantity and the second target quantity, a fourth target resistance branch is selected from the unselected resistance branches based on the third target quantity, and the fourth target resistance branch and the second target resistance branch are determined as the first target resistance branch.
7. The LLC resonant converter fast voltage regulation method according to claim 1, wherein: The closed-loop control based on the output voltage of the LLC resonant converter includes: The PI control method is adopted to perform closed-loop control on the output voltage of the LLC resonant converter.
8. An LLC resonant converter fast voltage regulation system, characterized in that: The invention comprises an LLC resonant converter, a parallel resistance branch and a controller, wherein each resistance branch in the parallel resistance branch is provided with a first switching tube, and each resistance branch is connected in parallel to the output end of the LLC resonant converter through its corresponding first switching tube, and the control end of the LLC resonant converter and the control end of the first switching tube are both communicatively connected to the controller, and the controller is configured to perform the steps of the method according to any one of claims 1 to 7.
9. A controller comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.
10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.