CN-122026732-A - LLC resonant converter intelligent control system based on self-adaptive frequency adjustment

CN122026732ACN 122026732 ACN122026732 ACN 122026732ACN-122026732-A

Abstract

The application relates to the technical field of control of power electronic converters, and discloses an LLC resonant converter intelligent control system based on self-adaptive frequency adjustment; the system firstly acquires the current working frequency, the target working frequency, the system constraint parameter and the inherent characteristic parameter of the resonant cavity; the method comprises the steps of generating a frequency-time plane, generating a candidate frequency change track set meeting constraint, further quantitatively analyzing the frequency change rate impact risk and resonance point crossing impact risk of each candidate track by combining with the characteristics of a resonant cavity, obtaining the comprehensive risk value of each track through coupling calculation, selecting an optimal frequency change track according to the comprehensive risk value, generating a corresponding time-frequency instruction sequence and issuing the time-frequency instruction sequence to drive a power level to execute, and solving the problem that the dynamic reliability is limited due to transient impact caused by frequency hopping in the traditional method by finely planning a frequency change path and prospectively evaluating the dynamic risk.

Inventors

LI KUNMING
GONG ZHIGUO
CHEN CHUANG

Assignees

大连宏光电气有限公司

Dates

Publication Date: 20260512
Application Date: 20260415

Claims (9)

1. LLC resonant converter intelligent control system based on self-adaptation frequency adjustment, characterized in that, the system includes: The data acquisition module is used for acquiring frequency change data, system constraint parameter data and resonant cavity inherent characteristic parameter data of the LLC resonant converter; the track generation module is used for generating an LLC resonant converter candidate frequency change track set based on the frequency change data of the LLC resonant converter and the system constraint parameter data; The risk assessment module is used for analyzing the frequency change rate impact risk and resonance point crossing impact risk of each LLC resonant converter candidate frequency change track based on the LLC resonant converter candidate frequency change track set and in combination with the resonant cavity inherent characteristic parameter data of the LLC resonant converter; The risk quantization module is used for quantizing the comprehensive risk of each LLC resonant converter candidate frequency change track based on the frequency change rate impact risk and resonance point crossing impact risk of each LLC resonant converter candidate frequency change track; and the decision execution module is used for selecting the optimal LLC resonant converter candidate frequency change track based on the comprehensive risk of each LLC resonant converter candidate frequency change track and generating a time-frequency instruction sequence for driving the LLC resonant converter power level to execute.
2. The intelligent control system for an LLC resonant converter based on adaptive frequency adjustment according to claim 1, wherein said obtaining frequency variation data, system constraint parameter data, and resonant cavity intrinsic characteristic parameter data of the LLC resonant converter includes the following specific contents: Acquiring frequency change data of an LLC resonant converter, specifically reading the current working frequency from a pulse width modulation module register of a digital controller, and receiving a target working frequency issued by an upper-level closed-loop controller from a system communication bus; acquiring system constraint parameter data of the LLC resonant converter, and particularly reading a maximum allowable frequency change rate, a safe frequency hopping amplitude and a system control period from a nonvolatile memory; and acquiring the intrinsic characteristic parameter data of the resonant cavity of the LLC resonant converter, and particularly reading the resonant frequency, the resonant cavity inertia time constant and the nonlinear sensitive interval radius from a nonvolatile memory.
3. The intelligent control system of an LLC resonant converter based on adaptive frequency adjustment according to claim 2, wherein the generating of the LLC resonant converter candidate frequency variation trajectory set based on frequency variation data and system constraint parameter data of the LLC resonant converter includes the following specific contents: Extracting the current working frequency and the target working frequency from frequency change data of an LLC resonant converter, extracting the maximum allowable frequency change rate, the safe frequency jump amplitude and the system control period from system constraint parameter data of the LLC resonant converter, and establishing a search graph taking time as a horizontal axis and frequency as a vertical axis, wherein the search graph specifically comprises the initial coordinate of the current working frequency of the LLC resonant converter, the end point coordinate of the target working frequency of the LLC resonant converter, and the basic step length of search as the system control period of the LLC resonant converter; Based on the search graph with time as a horizontal axis and frequency as a vertical axis, the maximum allowable frequency change rate and the safe frequency jump amplitude of the LLC resonant converter, performing constrained random exploration, generating LLC resonant converter candidate frequency change tracks, and constructing an LLC resonant converter candidate frequency change track set through running the random exploration process for a plurality of times.
4. An intelligent control system for an LLC resonant converter based on adaptive frequency tuning as claimed in claim 3, wherein said analysis of the frequency change rate impact risk and resonance point crossing impact risk of each LLC resonant converter candidate frequency change trace in combination with the LLC resonant converter candidate frequency change trace set, includes the following specific contents: Reading all adjacent point pairs formed by time-frequency points in each candidate frequency change track from the LLC resonant converter candidate frequency change track set, calculating the absolute value of the difference value between the frequency value at the later time and the frequency value at the former time aiming at each pair of adjacent points, dividing the absolute value by the time difference value between the later time and the former time to obtain the instantaneous frequency change speed of the adjacent point pair, and taking the maximum value of the instantaneous frequency change speed of all the adjacent point pairs as the maximum instantaneous frequency change rate of each LLC resonant converter candidate frequency change track; Calculating to obtain a frequency change rate impact risk value of each LLC resonant converter candidate frequency change track based on the maximum instantaneous frequency change rate of each LLC resonant converter candidate frequency change track, the maximum allowable frequency change rate of the LLC resonant converter and a system control period by combining with a resonant cavity inertia time constant in resonant cavity intrinsic characteristic parameter data; The method comprises the steps of reading resonant frequency, resonant cavity inertia time constant and nonlinear sensitive interval radius from resonant cavity inherent characteristic parameter data, checking whether the frequency range of each LLC resonant converter candidate frequency change track enters a specific frequency range which takes the resonant frequency as the center and takes the nonlinear sensitive interval radius as an offset, judging that the track does not pass through a risk area if all frequency points of the candidate frequency change track are out of the specific frequency range, judging that the resonant point pass through impact risk value of the LLC resonant converter candidate frequency change track is zero, and identifying and counting the total number of frequency points in the risk area if part of frequency points of the candidate frequency change track fall into the specific frequency range, so that the resonant point pass through impact risk value of the LLC resonant converter candidate frequency change track is comprehensively calculated.
5. The intelligent control system of an LLC resonant converter based on adaptive frequency adjustment according to claim 4, wherein the risk of frequency change rate impact and risk of resonance point crossing impact based on each LLC resonant converter candidate frequency change trace quantifies the overall risk of each LLC resonant converter candidate frequency change trace, including the following specific contents: sequentially reading a frequency change rate impact risk value and a resonance point crossing impact risk value of each LLC resonant converter candidate frequency change track from the risk evaluation module; and calculating the comprehensive risk value of each LLC resonant converter candidate frequency change track by adopting a geometric average model based on risk coupling amplification based on the frequency change rate impact risk value and resonance point crossing impact risk value of each LLC resonant converter candidate frequency change track.
6. The intelligent control system for an LLC resonant converter based on adaptive frequency adjustment according to claim 5, wherein said selecting an optimal LLC resonant converter candidate frequency variation trajectory based on the overall risk of each LLC resonant converter candidate frequency variation trajectory generates a time-frequency instruction sequence for driving the execution of an LLC resonant converter power stage, comprising the following specific contents: Reading all LLC resonant converter candidate frequency change tracks and a corresponding comprehensive risk value list generated after the risk quantization module processes, searching and determining the LLC resonant converter candidate frequency change track with the minimum comprehensive risk value, marking the LLC resonant converter candidate frequency change track as an optimal LLC resonant converter candidate frequency change track, and recording a unique track number and a complete time-frequency point sequence; Compiling a time-frequency point sequence contained in a candidate frequency change track of the optimal LLC resonant converter into a group of discrete control instructions according to a time sequence, wherein each instruction definitely contains a time stamp and a corresponding target switching frequency value, orderly transmitting the discrete control instructions to a digital pulse width modulation module of the LLC resonant converter through a system control bus, and updating the switching frequency to a corresponding target value at each appointed time point, so that the driving power level strictly completes the dynamic transition of a working point according to the planned optimal safety track.
7. An intelligent control method of an LLC resonant converter based on adaptive frequency adjustment, which is applied to an intelligent control system of an LLC resonant converter based on adaptive frequency adjustment as claimed in any one of claims 1 to 6, and is characterized by comprising the following steps: S1, obtaining frequency change data, system constraint parameter data and inherent characteristic parameter data of a resonant cavity of an LLC resonant converter; S2, generating an LLC resonant converter candidate frequency change track set based on frequency change data and system constraint parameter data of the LLC resonant converter; S3, analyzing the frequency change rate impact risk and resonance point crossing impact risk of each LLC resonant converter candidate frequency change track based on the LLC resonant converter candidate frequency change track set and by combining the intrinsic characteristic parameter data of the resonant cavity of the LLC resonant converter; S4, quantifying the comprehensive risk of each LLC resonant converter candidate frequency change track based on the frequency change rate impact risk and resonance point crossing impact risk of each LLC resonant converter candidate frequency change track; and S5, selecting an optimal LLC resonant converter candidate frequency change track based on the comprehensive risk of each LLC resonant converter candidate frequency change track, and generating a time-frequency instruction sequence for driving the LLC resonant converter power level to execute.
8. An electronic device comprising a processor and a memory, wherein the memory stores a computer program for the processor to call, and the processor is applied to the intelligent control system of the LLC resonant converter based on adaptive frequency adjustment according to any one of claims 1-6 by calling the computer program stored in the memory.
9. A computer readable storage medium storing instructions which, when run on a computer, cause the computer to apply to the LLC resonant converter intelligent control system based on adaptive frequency regulation as claimed in any of claims 1-6.

Description

LLC resonant converter intelligent control system based on self-adaptive frequency adjustment Technical Field The application relates to the technical field of control of power electronic converters, in particular to an LLC resonant converter intelligent control system based on self-adaptive frequency adjustment. Background The LLC resonant converter can realize zero-voltage switching of a primary side switching tube and zero-current switching of a secondary side rectifying tube, so that the LLC resonant converter is popular in power supply application with high requirements on efficiency and power density, but has obvious problems in the dynamic working process along with the increasing requirements on dynamic response speed of application scenes, such as occasions requiring to cope with rapid load change, such as a server power supply and an electric vehicle-mounted charger. The prior art usually takes the frequency as a control parameter which can be directly set, and the dynamic adjustment is realized by a classical closed loop feedback structure, which essentially simplifies the dynamic process into instantaneous or quick point-to-point jump, and the core assumption is that the resonant cavity can instantly catch up with a frequency command to establish a new steady state, and the LLC resonant network is actually a second-order system with obvious inertia and nonlinear characteristics, when the frequency command is subjected to step change, the current and capacitance voltage states of the resonant cavity cannot be suddenly changed, and the phase is inevitably severely adjusted and the energy is redistributed in the transition process. The prior art completely ignores the physical reality, and has the direct effects that during the frequency jump, the zero crossing point of the resonant current can generate serious deviation or distortion, so that the energy for completing zero-voltage switching in the dead time is insufficient, the switching tube is forced to enter a hard switching state, extra switching loss and electromagnetic interference are brought, the safety of a device can be threatened, meanwhile, the current peak appearing in a transient state can exceed the saturation limit value of a magnetic element or the rated current of the switching tube, the overcurrent risk is caused, and more importantly, when the frequency change passes through a high-gain nonlinear region near the resonant point, the tiny frequency disturbance can be amplified sharply, the loop is easily unstable, and the condition of continuous oscillation occurs. The control logic only pays attention to whether the final steady state is correct or not, but completely gives up the management and optimization of the safety of the transient process of the whole frequency change, so that the LLC resonant converter has to be further popularized and applied in the field of high performance and high reliability at the expense of reliability, efficiency and service life while pursuing fast dynamic response. Disclosure of Invention In order to overcome the defects, the application provides an LLC resonant converter intelligent control system based on self-adaptive frequency adjustment, and aims to solve the technical problems of transient ZVS failure, resonant current overshoot and dynamic reliability reduction caused by neglecting a frequency change process in the traditional closed-loop feedback control. In order to achieve the above purpose, the present application adopts the following technical scheme: in a first aspect, the present application provides an LLC resonant converter intelligent control system based on adaptive frequency adjustment, comprising: The data acquisition module is used for acquiring frequency change data, system constraint parameter data and resonant cavity inherent characteristic parameter data of the LLC resonant converter; the track generation module is used for generating an LLC resonant converter candidate frequency change track set based on the frequency change data of the LLC resonant converter and the system constraint parameter data; The risk assessment module is used for analyzing the frequency change rate impact risk and resonance point crossing impact risk of each LLC resonant converter candidate frequency change track based on the LLC resonant converter candidate frequency change track set and in combination with the resonant cavity inherent characteristic parameter data of the LLC resonant converter; The risk quantization module is used for quantizing the comprehensive risk of each LLC resonant converter candidate frequency change track based on the frequency change rate impact risk and resonance point crossing impact risk of each LLC resonant converter candidate frequency change track; and the decision execution module is used for selecting the optimal LLC resonant converter candidate frequency change track based on the comprehensive risk of each LLC resonant converter candidate frequency change