CN117526724A - Dynamic resonant frequency tracking method and system for full-bridge LLC resonant converter - Google Patents
Dynamic resonant frequency tracking method and system for full-bridge LLC resonant converter Download PDFInfo
- Publication number
- CN117526724A CN117526724A CN202311459357.1A CN202311459357A CN117526724A CN 117526724 A CN117526724 A CN 117526724A CN 202311459357 A CN202311459357 A CN 202311459357A CN 117526724 A CN117526724 A CN 117526724A
- Authority
- CN
- China
- Prior art keywords
- resonant
- frequency
- resonance
- switching frequency
- resonant frequency
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 39
- 238000003860 storage Methods 0.000 claims description 13
- 230000003068 static effect Effects 0.000 claims description 7
- 238000004590 computer program Methods 0.000 claims description 5
- 230000000630 rising effect Effects 0.000 claims description 5
- 238000004364 calculation method Methods 0.000 claims description 3
- 230000032683 aging Effects 0.000 abstract description 5
- 230000008859 change Effects 0.000 abstract description 4
- 238000009826 distribution Methods 0.000 abstract description 4
- 230000010485 coping Effects 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 10
- 238000004458 analytical method Methods 0.000 description 8
- 230000003287 optical effect Effects 0.000 description 6
- 238000004088 simulation Methods 0.000 description 6
- 230000006872 improvement Effects 0.000 description 5
- 238000012545 processing Methods 0.000 description 5
- 230000009286 beneficial effect Effects 0.000 description 4
- 238000013461 design Methods 0.000 description 4
- 230000005284 excitation Effects 0.000 description 3
- 230000004075 alteration Effects 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000006870 function Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000013307 optical fiber Substances 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 230000000644 propagated effect Effects 0.000 description 2
- 238000003491 array Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 230000003071 parasitic effect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/3353—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having at least two simultaneously operating switches on the input side, e.g. "double forward" or "double (switched) flyback" converter
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/0048—Circuits or arrangements for reducing losses
- H02M1/0054—Transistor switching losses
- H02M1/0058—Transistor switching losses by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The invention relates to the technical field of resonant converters, and discloses a method and a system for dynamically tracking resonant frequency of a full-bridge LLC resonant converter, which are based on a resonant offset factor delta T f And a resonance shift factor reference value DeltaT f_ref Compared with the prior art, the full-bridge LLC resonant converter can dynamically track the operation of the full-bridge LLC resonant converter at the resonant frequency point or slightly left side of the resonant frequency point, realize zero-voltage turn-on of a primary side switching tube and zero-current turn-off of a secondary side diode in a self-adaptive manner, improve the efficiency of the converter, and reduce the loss of a system, thereby effectively solving the problem of difference between actual resonant frequency and theoretical preset resonant frequency caused by self-parameter precision of resonant devices, different modes of device combination, line distribution parameters and the like in batch products, coping with resonant frequency change caused by aging of the resonant devices, eliminating control errors to a certain extent, and having certain timeliness.
Description
Technical Field
The invention relates to the technical field of resonant converters, in particular to a method and a system for dynamically tracking resonant frequency of a full-bridge LLC resonant converter.
Background
The LLC resonant converter can be equivalently a resonant circuit consisting of an inductance (L), a capacitance (C) and a resistance (R). The working principle of the energy-saving device is based on resonance phenomenon, and the resonance circuit is made to form resonance between input and output voltages by adjusting the values of inductance, capacitance and resistance, so that efficient energy transmission is realized.
Because LLC resonant converter is the highest in resonant frequency point efficiency, so in the application of many two-stage circuit, LLC is as preceding coarse tuning voltage, and the second stage circuit carries out output voltage accurate control, in this kind of system, can directly let LLC open-loop work in resonant frequency point, does not carry out closed loop to the output and adjust operating frequency, just uses LLC as a direct current transformer, not only control is simple, and system efficiency is high moreover.
Under the fixed frequency and fixed duty ratio control mode, the LLC resonant converter can theoretically work at a calculated resonant frequency point, but because the parameter deviation of a resonant element has a certain influence on the actual resonant frequency of the resonant converter, in practical application, the actual parameter of the LLC resonant converter element deviates from a preset parameter due to the problems of manufacturing process, use aging and the like, so that the actual resonant frequency is changed, the actual resonant frequency is not equal to the preset resonant frequency, the LLC resonant converter is not beneficial to stably work near the resonant frequency point, and the efficiency of the converter is improved to a certain extent. When the converter is mass-produced, it is difficult to ensure that the hardware parameters of each product are completely consistent, and in order to enable each product to operate at its own resonant frequency point, a method for adaptively identifying the resonant frequency point of the current machine is required to ensure that each machine achieves the maximum conversion efficiency.
At present, the existing technology for automatically tracking the resonant frequency of the LLC resonant converter is not sufficiently mature, and the control mode is relatively complex and has low practicability.
Accordingly, improvements in the art are needed.
The above information is presented as background information only to aid in the understanding of the present disclosure and is not intended or admitted to be prior art relative to the present disclosure.
Disclosure of Invention
The invention provides a method and a system for dynamically tracking resonant frequency of a full-bridge LLC resonant converter, which are used for solving the problems in the prior art.
In order to achieve the above object, the present invention provides the following technical solutions:
in a first aspect, the present invention provides a method of dynamically tracking resonant frequency of a full bridge LLC resonant converter, said method comprising:
collecting the time tD_up when the secondary side rectifying diode voltage Vds starts to rise and the time tG_down when the primary side switching tube driving signal Vg1 starts to fall;
the resonance shift factor Δtf is calculated according to the following formula:
ΔTf＝tD_up-tG_down；
judging whether delta Tf is smaller than delta Tf_ref, wherein delta Tf_ref is a resonance offset factor reference value;
if yes, the switching frequency fs is smaller than the resonance frequency fr, and the P I controller is used for adjusting the switching frequency fs to increase the switching frequency fs so as to realize dynamic tracking of the resonance frequency fr; if not, judging whether delta Tf is more than 0;
if yes, the switching frequency fs is larger than the resonance frequency fr, and the P I controller is used for adjusting the switching frequency fs to reduce the switching frequency fs, so that dynamic tracking of the resonance frequency fr is realized; if not, the switching frequency fs is kept unchanged.
Further, in the method for dynamically tracking resonant frequency of the full-bridge LLC resonant converter, the step of adjusting the switching frequency fs with a P I controller includes:
superposing the difference value between the resonance offset factor reference value delta Tf_ref and the resonance offset factor delta Tf to an initial switching frequency fs0 through a PI controller;
and dynamically adjusting the switching frequency fs by using a PI controller, so that the resonance offset factor delta Tf is tracked to the resonance offset factor reference value delta Tf_ref without static difference.
Further, in the method for dynamically tracking resonant frequency of the full-bridge LLC resonant converter, the method further includes:
the value of the resonance shift factor Δtf when the full-bridge LLC resonant converter operates at the actual resonance frequency point or slightly left interval of the resonance frequency point is set to the resonance shift factor reference value Δtf_ref.
In a second aspect, the present invention provides a dynamic tracking resonant frequency system for a full bridge LLC resonant converter, said system comprising:
the acquisition module is used for acquiring the time tD_up when the secondary side rectifier diode voltage Vds starts to rise and the time tG_down when the primary side switch tube driving signal Vg1 starts to fall;
a calculation module for calculating a resonance shift factor Δtf according to the following formula:
ΔTf＝tD_up-tG_down；
the judging module is used for judging whether delta Tf is smaller than delta Tf_ref, wherein delta Tf_ref is a resonance offset factor reference value; if yes, the switching frequency fs is smaller than the resonance frequency fr, and the P I controller is used for adjusting the switching frequency fs to increase the switching frequency fs so as to realize dynamic tracking of the resonance frequency fr; if not, judging whether delta Tf is more than 0;
if yes, the switching frequency fs is larger than the resonance frequency fr, and the P I controller is used for adjusting the switching frequency fs to reduce the switching frequency fs, so that dynamic tracking of the resonance frequency fr is realized; if not, the switching frequency fs is kept unchanged.
Further, in the dynamic tracking resonant frequency system of the full-bridge LLC resonant converter, the step of adjusting the switching frequency fs by using the PI controller performed by the determining module specifically includes:
superposing the difference value between the resonance offset factor reference value delta Tf_ref and the resonance offset factor delta Tf to an initial switching frequency fs0 through a PI controller;
and dynamically adjusting the switching frequency fs by using a PI controller, so that the resonance offset factor delta Tf is tracked to the resonance offset factor reference value delta Tf_ref without static difference.
Further, in the dynamic tracking resonant frequency system of the full-bridge LLC resonant converter, the system further includes a setting module for:
the value of the resonance shift factor Δtf when the full-bridge LLC resonant converter operates at the actual resonance frequency point or slightly left interval of the resonance frequency point is set to the resonance shift factor reference value Δtf_ref.
In a third aspect, the invention provides a computer device comprising a memory storing a computer program and a processor implementing a method for dynamically tracking resonant frequency of a full-bridge LLC resonant converter according to the first aspect described above when said computer program is executed.
In a fourth aspect, the present invention provides a storage medium containing computer executable instructions for execution by a computer processor to implement the method of dynamically tracking resonant frequency of a full bridge LLC resonant converter as described in the first aspect above.
Compared with the prior art, the invention has the following beneficial effects:
the invention provides a method and a system for dynamically tracking resonant frequency of a full-bridge LLC resonant converter, which are based on a resonant offset factor delta T f And a resonance shift factor reference value DeltaT f_ref Compared with the prior art, the full-bridge LLC resonant converter can dynamically track the operation of the full-bridge LLC resonant converter at the resonant frequency point or slightly left side of the resonant frequency point, adaptively realize zero-voltage turn-on of a primary side switching tube and zero-current turn-off of a secondary side diode, improve the efficiency of the converter, reduce the loss of a system, effectively solve the problem of difference between actual resonant frequency and theoretical preset resonant frequency caused by parameter precision of resonant devices, different modes of device combination, line distribution parameters and the like in batch products, and cope with the change of resonant frequency caused by ageing of the resonant devices, eliminate control errors to a certain extent, have certain timeliness, and have simple control modes, easy realization and strong practicability。
The invention has other features and advantages which will be apparent from or are set forth in detail in the accompanying drawings and the following detailed description, which are incorporated herein, taken in conjunction with the accompanying drawings and the detailed description, which illustrate certain principles of the invention.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a full bridge LLC resonant converter topology;
FIG. 2 is a schematic diagram of an LLC resonant converter voltage gain curve;
FIG. 3 is a diagram of an under-resonance simulation analysis;
FIG. 4 is a graph of a simulation analysis of resonant frequency points;
FIG. 5 is a diagram of an over-resonance simulation analysis;
FIG. 6 is a schematic flow chart of a method for dynamically tracking resonant frequency of a full-bridge LLC resonant converter according to an embodiment of the present invention;
FIG. 7 is a block diagram of a full-bridge LLC resonant frequency point dynamic tracking control according to an embodiment of the present invention;
FIG. 8 is a schematic diagram of a functional module of a dynamic tracking resonant frequency system of a full-bridge LLC resonant converter according to a second embodiment of the present invention;
fig. 9 is a schematic structural diagram of a computer device according to a third embodiment of the present invention.
Detailed Description
For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure. In addition, as one of ordinary skill in the art can appreciate, with technical development and new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.
In the description of the present application, it is to be understood that all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs unless defined otherwise. Furthermore, any terminology used is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.
In addition, numerous specific details are set forth in the following detailed description in order to provide a better understanding of the present application. It will be understood by those skilled in the art that the present application may be practiced without some of these specific details. In some instances, methods, means, elements, and circuits have not been described in detail as not to unnecessarily obscure the present application.
The technical scheme of the invention is further described below by the specific embodiments with reference to the accompanying drawings.
Example 1
In view of the above-mentioned drawbacks of the prior art, the applicant has actively studied and innovated based on the fact that the design and manufacture of such products have been carried out for many years and in combination with the application of the theory, in order to hope to create a technology capable of solving the drawbacks of the prior art. After continuous research and design and repeated sample test and improvement, the invention with practical value is finally created.
First, the topology architecture and operating characteristics of the full-bridge LLC resonant converter are explained:
the full-bridge LLC resonant converter topology is shown in fig. 1, assuming that power flows from left to right for forward operation and from right to left for reverse operation. Transformer bodyFour power switch tubes Q on side 1 -Q 4 Forms an input side full bridge, a secondary side Q 5 -Q 8 Form an output side full bridge, C in the figure 1 -C 8 Respectively switch tube Q 1 -Q 8 Parasitic capacitance of D 1 -D 8 Respectively switch tube Q 1 -Q 8 Is provided. When power is transmitted forward, the input side full bridge is in an inversion state, and the output side full bridge is in a rectification state. Two full bridges pass through transformer T r Connection, T r Is a high-frequency transformer L m Is an excitation inductance L r Is externally connected with a resonant inductor C r For the resonance capacitance, the primary and secondary side turn ratio of the transformer is n:1. when the full-bridge LLC resonant converter is in forward operation, two resonant frequency points are arranged, and the low-frequency resonant frequency f m And a high frequency resonance frequency f r Expressed as:
in the forward operation of the resonant converter, the operating state of the resonant converter can be divided into three sections according to the comparison of the switching frequency and the resonant frequency: f (f) s <f m ，f m <f s <f r (under resonance), f s >f r (over-resonance), f s ＝f r The transducer is operated in a fully resonant state. When f s <f m When the converter works in the capacitive section, the switching tube does not meet the condition of realizing soft switching, and analysis is not performed here. The driving signals of the diagonal switching tubes of the primary side inversion bridge of the transformer are consistent, the switching tubes of the same bridge arm are complementarily conducted, the duty ratio of the driving voltage is about 50%, and the dead time is adjusted according to specific parameters and switching frequency.
The expression of the voltage gain M of the full-bridge LLC resonant converter is shown in formula 4, and the voltage gain curve is shown in figure 2. In fixed frequency control modeUnder this condition, an error in the resonant device parameters will result in an actual resonant frequency f r The inductance lambda and the quality factor Q are changed, the voltage gain curve characteristic is changed, the gain of the original preset resonant frequency point is affected, the system is not beneficial to accurately working at the resonant frequency point or a slightly left interval of the resonant frequency point, and the improvement of the efficiency of the converter is inhibited to a certain extent.
For the proposed control method, the following three working conditions will be analyzed and explained:
1. when LLC resonant converter switching frequency f s Less than the resonant frequency f r When the LLC resonant converter works in the under-resonance section, the gain of the LLC resonant converter is larger than 1, and the simulation analysis chart is shown in FIG. 3. Analysis is carried out with a positive half-cycle, during which the converter operates with a resonant inductance L at a certain moment r Resonance capacitor C r Excitation inductance L of transformer m The three are resonant together, the phase is maintained until the dead zone begins to finish, the resonant cavity does not transfer energy to the secondary side, the secondary side current of the transformer is reduced to zero, the diode conduction voltage drop is ignored, and the secondary side rectifying diode D 5 Voltage V ds Starting from 0 to increase, V ds Instant t of sudden increase D_up Leading primary side switch tube Q 1 Drive signal V g1 Start falling time t G_down Detecting and calculating resonance shift factor delta T f ＝t D_up -t G_down The resonance shift factor Δtf is less than 0 and has a negative value in this operating state.
When LLC switching frequency f s Equal to the resonant frequency f r At this time, the LLC resonant converter works at a high-frequency resonant frequency point, and a simulation analysis chart is shown in fig. 4. The resonant cavity current is approximately sine wave, and the excitation inductance of the transformer is always equal to that of the resonant cavityThe square wave of the output voltage with the amplitude of n times is clamped and does not participate in resonance, the resonance impedance of the resonance inductance and the resonance capacitance is 0, and the current of the secondary side of the transformer is in a critical continuous state. In the positive half cycle stage, the secondary side rectifier diode D 5 Voltage V ds Start instant t of sudden increase D_up Just equal to the primary side switch tube Q 1 Drive signal V g1 Start falling time t G_down At this time, the resonance shift factor DeltaT f Equal to 0.
When LLC switching frequency f s Greater than the resonant frequency f r At this time, the LLC resonant converter operates in the over-resonance region, and the simulation analysis chart is shown in fig. 5. The exciting inductance in the interval is always clamped by the output voltage and does not participate in resonance, and only the resonance inductance L is arranged in the resonant cavity r And a resonance capacitor C r The circuit is in resonance, the operation characteristic at the moment is equivalent to LC series resonance, and the normalized voltage gain of the converter is always smaller than 1. Secondary rectifying diode D at this time 5 Voltage V ds Instant t of sudden increase D_up Hysteresis primary side switch tube Q 1 Drive signal V g1 Start falling time t G_down Detecting and calculating resonance shift factor delta T f ＝t D_up -t G_down Resonance shift factor DeltaT in this operating state f And greater than 0 is positive.
Referring to fig. 6, a flowchart of a method for dynamically tracking resonant frequency of a full-bridge LLC resonant converter according to an embodiment of the invention is shown, which is implemented by a system for dynamically tracking resonant frequency of a full-bridge LLC resonant converter, and the system can be implemented in software and/or hardware. The method specifically comprises the following steps:
s101, collecting secondary side rectifier diode voltage V ds Time t at which rising starts D_up With primary side switch tube driving signal V g1 Time t at which descent starts G_down 。
The method comprises the steps of collecting the secondary side rectifier diode voltage V by a hardware detection circuit ds Time t at which rising starts D_up With primary side switch tube driving signal V g1 Time t at which descent starts G_down In view of the hardnessThe specific circuit design of the detection circuit is realized in the prior art, and is not the focus of the design of the scheme, and is not further described herein.
S102, calculating a resonance shift factor delta T according to the following formula f ：
ΔT f ＝t D_up -t G_down 。
S103, judging whether delta T is f ＜ΔT f_ref Wherein DeltaT f_ref Is a resonance offset factor reference value; if yes, step S104 is executed, and if no, step S105 is executed.
In this embodiment, the method further includes a resonance shift factor reference value ΔT f_ref The setting process of (1), namely:
when the full-bridge LLC resonant converter is operated at the actual resonant frequency point or the interval slightly left of the resonant frequency point, the resonant offset factor delta T is used f The value of (2) is set as the resonance shift factor reference value DeltaT f_ref 。
S104, switching frequency f s Less than the resonant frequency f r Adjusting the switching frequency f by means of a PI controller s To increase the switching frequency f s Realize the resonance frequency f r Is described.
If DeltaT f ＜ΔT f_ref The full-bridge LLC resonant converter is operated in the left section of the resonant frequency point, and the switching frequency f s Less than the resonant frequency f r It is necessary to increase the switching frequency f s 。
S105, judging whether delta T is f > 0; if yes, step S106 is executed, and if no, step S107 is executed.
S106, switching frequency f s Greater than the resonant frequency f r Adjusting the switching frequency f by means of a PI controller s To reduce the switching frequency f s Realize the resonance frequency f r Is described.
If DeltaT f If more than 0, the full-bridge LLC resonant converter works in the right section of the resonant frequency point, and the switching frequency f s Greater than the resonant frequency f r There is a need to reduce the switching frequencyf s 。
S107 maintaining the switching frequency f s Is unchanged.
If DeltaT f_ref ≤ΔT f And the switching frequency is less than or equal to 0, which indicates that the full-bridge LLC resonant converter works at the resonant frequency point or in the interval slightly left of the resonant frequency point at the moment, and the switching frequency is in the optimal range. If DeltaT is to be f_ref And the switching frequency information is set to be 0, and the actual resonant frequency at the moment realizes the dynamic tracking of the resonant frequency point.
Referring to fig. 7, in the present embodiment, the switching frequency f is adjusted by a PI controller s The method comprises the following steps:
by reference of the resonance shift factor DeltaT f_ref And resonance shift factor DeltaT f The difference between them is superimposed to the initial switching frequency f by a PI controller s0 ；
Dynamic adjustment of switching frequency f using PI controller s By shifting the resonance by a factor DeltaT f Tracking to resonance offset factor reference value delta T without static difference f_ref 。
It should be noted that, as shown in fig. 7, the dynamic tracking control block diagram of the full-bridge LLC resonant frequency point refers to the resonant offset factor reference value Δt f_ref And resonance shift factor DeltaT f The difference between them is superimposed to the initial switching frequency f by a PI controller s0 Dynamic adjustment of the switching frequency f using a PI controller s By shifting the resonance by a factor DeltaT f Tracking to resonance offset factor reference value delta T without static difference f_ref Resonance offset factor reference value DeltaT f_ref The resonant frequency point of the full-bridge LLC resonant converter can be dynamically tracked by setting the resonant frequency point to be 0 or a negative value close to 0, and operating the LLC resonant converter at the resonant frequency point or slightly left interval of the resonant frequency point.
Although terms such as full bridge LLC resonant converter, dynamic tracking, resonant frequency, resonant offset factor, etc. are used more in this application, the possibility of using other terms is not precluded. These terms are used merely for convenience in describing and explaining the nature of the invention; they are to be interpreted as any additional limitation that is not inconsistent with the spirit of the present invention.
The invention provides a dynamic tracking resonant frequency method of a full-bridge LLC resonant converter, which is based on a resonant offset factor delta T f And a resonance shift factor reference value DeltaT f_ref Compared with the prior art, the full-bridge LLC resonant converter can dynamically track the operation of the full-bridge LLC resonant converter at the resonant frequency point or slightly left side of the resonant frequency point, realize zero-voltage turn-on of a primary side switching tube and zero-current turn-off of a secondary side diode in a self-adaptive manner, improve the efficiency of the converter, and reduce the loss of a system, thereby effectively solving the problem of difference between actual resonant frequency and theoretical preset resonant frequency caused by self-parameter precision of resonant devices, different modes of device combination, line distribution parameters and the like in batch products, coping with resonant frequency change caused by aging of the resonant devices, eliminating control errors to a certain extent, and having certain timeliness.
Example two
Referring to fig. 8, a second embodiment of the present invention provides a system for dynamically tracking resonant frequency of a full-bridge LLC resonant converter, which is suitable for executing the method for dynamically tracking resonant frequency of a full-bridge LLC resonant converter according to the embodiments of the present invention. The system specifically comprises the following modules:
an acquisition module 301 for acquiring a secondary side rectifier diode voltage V ds Time t at which rising starts D_up With primary side switch tube driving signal V g1 Time t at which descent starts G_down ；
A calculation module 302 for calculating a resonance shift factor DeltaT according to the following formula f ：
ΔT f ＝t D_up -t G_down ；
A judging module 303 for judging whether DeltaT is f ＜ΔT f_ref Wherein DeltaT f_ref Is a resonance offset factor reference value; if yes, the switching frequency f s Less than the resonant frequency f r Adjusting the switching frequency f by means of a PI controller s To increase the switching frequency f s Realize the resonance frequency f r Is a dynamic tracking of (1); if not, judge whether DeltaT f ＞0；
If yes, the switching frequency f s Greater than the resonant frequency f r Adjusting the switching frequency f by means of a PI controller s To reduce the switching frequency f s Realize the resonance frequency f r Is a dynamic tracking of (1); if not, the switching frequency f is maintained s Is unchanged.
Preferably, the switching frequency f is adjusted by the PI controller executed by the judging module 303 s The method specifically comprises the following steps:
by reference of the resonance shift factor DeltaT f_ref And resonance shift factor DeltaT f The difference between them is superimposed to the initial switching frequency f by a PI controller s0 ；
Dynamic adjustment of switching frequency f using P I controller s By shifting the resonance by a factor DeltaT f Tracking to resonance offset factor reference value delta T without static difference f_ref 。
Preferably, the system further comprises a setting module for:
when the full-bridge LLC resonant converter is operated at the actual resonant frequency point or the interval slightly left of the resonant frequency point, the resonant offset factor delta T is used f The value of (2) is set as the resonance shift factor reference value DeltaT f_ref 。
The invention provides a dynamic tracking resonant frequency system of a full-bridge LLC resonant converter, which is based on a resonant offset factor delta T f And a resonance shift factor reference value DeltaT f_ref Compared with the prior art, the full-bridge LLC resonant converter can dynamically track the operation of the full-bridge LLC resonant converter at the resonant frequency point or slightly left side of the resonant frequency point, realize zero-voltage turn-on of a primary side switching tube and zero-current turn-off of a secondary side diode in a self-adaptive manner, improve the efficiency of the converter, and reduce the loss of a system, thereby effectively solving the problem of difference between actual resonant frequency and theoretical preset resonant frequency caused by self-parameter precision of resonant devices, different modes of device combination, line distribution parameters and the like in batch products, coping with resonant frequency change caused by aging of the resonant devices, eliminating control errors to a certain extent, and having certain timeliness.
The system can execute the method provided by any embodiment of the invention, and has the corresponding functional modules and beneficial effects of executing the method.
Example III
Fig. 9 is a schematic structural diagram of a computer device according to a third embodiment of the present invention. Fig. 9 illustrates a block diagram of an exemplary computer device 12 suitable for use in implementing embodiments of the present invention. The computer device 12 shown in fig. 9 is merely an example and should not be construed as limiting the functionality and scope of use of embodiments of the present invention.
As shown in fig. 9, the computer device 12 is in the form of a general purpose computing device. Components of computer device 12 may include, but are not limited to: one or more processors or processing units 16, a system memory 28, a bus 18 that connects the various system components, including the system memory 28 and the processing units 16.
Bus 18 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processor, and a local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, micro channel architecture (MAC) bus, enhanced ISA bus, video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus.
Computer device 12 typically includes a variety of computer system readable media. Such media can be any available media that is accessible by computer device 12 and includes both volatile and nonvolatile media, removable and non-removable media.
The system memory 28 may include computer system readable media in the form of volatile memory, such as Random Access Memory (RAM) 30 and/or cache memory 32. The computer device 12 may further include other removable/non-removable, volatile/nonvolatile computer system storage media. By way of example only, storage system 34 may be used to read from or write to non-removable, nonvolatile magnetic media (not shown in FIG. 9, commonly referred to as a "hard disk drive"). Although not shown in fig. 9, a magnetic disk drive for reading from and writing to a removable non-volatile magnetic disk (e.g., a "floppy disk"), and an optical disk drive for reading from or writing to a removable non-volatile optical disk (e.g., a CD-ROM, DVD-ROM, or other optical media) may be provided. In such cases, each drive may be coupled to bus 18 through one or more data medium interfaces. Memory 28 may include at least one program product having a set (e.g., at least one) of program modules configured to carry out the functions of embodiments of the invention.
A program/utility 40 having a set (at least one) of program modules 42 may be stored in, for example, memory 28, such program modules 42 including, but not limited to, an operating system, one or more application programs, other program modules, and program data, each or some combination of which may include an implementation of a network environment. Program modules 42 generally perform the functions and/or methods of the embodiments described herein.
The computer device 12 may also communicate with one or more external devices 14 (e.g., keyboard, pointing device, display 24, etc.), one or more devices that enable a user to interact with the computer device 12, and/or any devices (e.g., network card, modem, etc.) that enable the computer device 12 to communicate with one or more other computing devices. Such communication may occur through an input/output (I/O) interface 22. Moreover, computer device 12 may also communicate with one or more networks such as a Local Area Network (LAN), a Wide Area Network (WAN) and/or a public network, such as the Internet, through network adapter 20. As shown, network adapter 20 communicates with other modules of computer device 12 via bus 18. It should be appreciated that although not shown in fig. 9, other hardware and/or software modules may be used in connection with computer device 12, including, but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, data backup storage systems, and the like.
The processing unit 16 executes various functional applications and data processing by running programs stored in the system memory 28, for example, implementing the method for dynamically tracking resonant frequency of a full-bridge LLC resonant converter provided by embodiments of the invention.
Example IV
A fourth embodiment of the present invention provides a computer-readable storage medium having stored thereon computer-executable instructions that, when executed by a processor, implement a method for dynamically tracking resonant frequencies of a full-bridge LLC resonant converter as provided in all the inventive embodiments of the present application.
Any combination of one or more computer readable media may be employed. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. The computer readable storage medium can be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or a combination of any of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
The computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, either in baseband or as part of a carrier wave. Such a propagated data signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination of the foregoing. A computer readable signal medium may also be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.
Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
Computer program code for carrying out operations of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, smalltalk, C ++ and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any kind of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computer (for example, through the Internet using an Internet service provider).
In view of the foregoing, it will be evident to a person skilled in the art that the foregoing detailed disclosure may be presented by way of example only and may not be limiting. Although not explicitly described herein, those skilled in the art will appreciate that the present application is intended to embrace a variety of reasonable alterations, improvements and modifications to the embodiments. Such alterations, improvements, and modifications are intended to be proposed by this application, and are intended to be within the spirit and scope of the exemplary embodiments of this application.
Furthermore, certain terms in the present application have been used to describe embodiments of the present application. For example, "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. Thus, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various portions of this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined as suitable in one or more embodiments of the application.
It should be appreciated that in the foregoing description of embodiments of the present application, various features are grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the application. However, this is not to say that a combination of these features is necessary, and it is entirely possible for a person skilled in the art to extract some of them as separate embodiments to understand them at the time of reading this application. That is, embodiments in this application may also be understood as an integration of multiple secondary embodiments. While each secondary embodiment is satisfied by less than all of the features of a single foregoing disclosed embodiment.
Finally, it should be understood that the embodiments of the application disclosed herein are illustrative of the principles of the embodiments of the present application. Other modified embodiments are also within the scope of the present application. Accordingly, the embodiments disclosed herein are by way of example only and not limitation. Those skilled in the art can adopt alternative configurations to implement the applications herein according to embodiments herein. Accordingly, embodiments of the present application are not limited to the embodiments precisely described in the application.
Claims (8)
1. A method of dynamically tracking resonant frequency of a full-bridge LLC resonant converter, the method comprising:
collecting secondary side rectifier diode voltage V ds Time t at which rising starts D_up With primary side switch tube driving signal V g1 Time t at which descent starts G_down ；
The resonance shift factor DeltaT is calculated according to the following formula f ：
ΔT f ＝t D_up -t G_down ；
Determine whether DeltaT f ＜ΔT f_ref Wherein DeltaT f_ref Is a resonance offset factor reference value;
if yes, the switching frequency f s Less than the resonant frequency f r Adjusting the switching frequency f by means of a PI controller s To increase the switching frequency f s Realize the resonance frequency f r Is a dynamic tracking of (1); if not, judge whether DeltaT f ＞0；
If yes, the switching frequency f s Greater than the resonant frequency f r Adjusting the switching frequency f by means of a PI controller s To reduce the switching frequency f s Realize the resonance frequency f r Is a dynamic tracking of (1); if not, the switching frequency f is maintained s Is unchanged.
2. The method for dynamically tracking resonant frequency of full-bridge LLC resonant converter in accordance with claim 1, wherein said adjusting the switching frequency f with a PI controller s The method comprises the following steps:
by reference of the resonance shift factor DeltaT f_ref And resonance shift factor DeltaT f The difference between them is superimposed to the initial switching frequency f by a PI controller s0 ；
Dynamic adjustment of switching frequency f using PI controller s By shifting the resonance by a factor DeltaT f Tracking to resonance offset factor reference value delta T without static difference f_ref 。
3. The method of dynamically tracking resonant frequency of a full-bridge LLC resonant converter of claim 1, further comprising:
when the full-bridge LLC resonant converter is operated at the actual resonant frequency point or the interval slightly left of the resonant frequency point, the resonant offset factor delta T is used f The value of (2) is set as the resonance shift factor reference value DeltaT f_ref 。
4. A dynamic tracking resonant frequency system for a full-bridge LLC resonant converter, said system comprising:
the acquisition module is used for acquiring the voltage V of the secondary rectifying diode ds Time t at which rising starts D_up With primary side switch tube driving signal V g1 Time t at which descent starts G_down ；
A calculation module for calculating a resonance shift factor DeltaT according to the following formula f ：
ΔT f ＝t D_up -t G_down ；
A judging module for judging whether delta T is present f ＜ΔT f_ref Wherein DeltaT f_ref Is a resonance offset factor reference value; if yes, the switching frequency f s Less than the resonant frequency f r Adjusting the switching frequency f by means of a PI controller s To increase the switching frequency f s Realize the resonance frequency f r Is a dynamic tracking of (1); if not, judge whether DeltaT f ＞0；
If yes, the switching frequency f s Greater than the resonant frequency f r Adjusting the switching frequency f by means of a PI controller s To reduce the switching frequency f s Realize the resonance frequency f r Is a dynamic tracking of (1); if not, the switching frequency f is maintained s Is unchanged.
5. The system according to claim 4, wherein the determination module executes the step of adjusting the switching frequency f using a PI controller s The method specifically comprises the following steps:
by reference of the resonance shift factor DeltaT f_ref And resonance shift factor DeltaT f The difference between them is superimposed to the initial switching frequency f by a PI controller s0 ；
Dynamic adjustment of switching frequency f using PI controller s By shifting the resonance by a factor DeltaT f Tracking to resonance offset factor reference value delta T without static difference f_ref 。
6. The system for dynamically tracking resonant frequency of a full-bridge LLC resonant converter of claim 4, further comprising a setting module for:
when the full-bridge LLC resonant converter is operated at the actual resonant frequency point or the interval slightly left of the resonant frequency point, the resonant offset factor delta T is used f The value of (2) is set as the resonance shift factor reference value DeltaT f_ref 。
7. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements a method of dynamically tracking resonant frequency of a full-bridge LLC resonant converter according to any of claims 1-3 when said computer program is executed.
8. A storage medium containing computer executable instructions for execution by a computer processor to implement the method of dynamically tracking resonant frequency of a full-bridge LLC resonant converter according to any of claims 1-3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311459357.1A CN117526724A (en) | 2023-11-03 | 2023-11-03 | Dynamic resonant frequency tracking method and system for full-bridge LLC resonant converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311459357.1A CN117526724A (en) | 2023-11-03 | 2023-11-03 | Dynamic resonant frequency tracking method and system for full-bridge LLC resonant converter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117526724A true CN117526724A (en) | 2024-02-06 |
Family
ID=89748767
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311459357.1A Pending CN117526724A (en) | 2023-11-03 | 2023-11-03 | Dynamic resonant frequency tracking method and system for full-bridge LLC resonant converter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117526724A (en) |
-
2023
- 2023-11-03 CN CN202311459357.1A patent/CN117526724A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10291136B2 (en) | Control device and control method | |
| US10333418B2 (en) | Control device and control method | |
| US8335095B2 (en) | One cycle control method for power factor correction | |
| US10686382B2 (en) | Symmetric time shift control for resonant converters | |
| CN110611431B (en) | Primary side regulation control system and control method of active clamp flyback converter | |
| Guidi et al. | Dual active bridge modulation with complete zero voltage switching taking resonant transitions into account | |
| CN112994470B (en) | Primary side feedback active clamping flyback converter, controller and control method | |
| CN113937988A (en) | Asymmetric half-bridge flyback converter and control method thereof | |
| CN105515366A (en) | Mixing control method used for LCC resonance DC-DC converter | |
| Wei et al. | Comprehensive comparisons between frequency‐domain analysis and time‐domain analysis for LLC resonant converter | |
| CN115224944A (en) | Control method of variable topology resonant converter with smooth switching function | |
| CN111049392A (en) | Double-active-bridge expanded phase-shifting minimum reflux power control method based on coordinate transformation | |
| CN112311222A (en) | Improved bridgeless DBPFC converter based on composite prediction current control and control method | |
| Wei et al. | Simple and effective adaptive deadtime strategies for LLC resonant converter: analysis, design, and implementation | |
| CN114208013A (en) | Resonant converter and voltage conversion method | |
| CN207968329U (en) | A kind of LLC controller | |
| CN113949283A (en) | Dead time influence considered light load gain analysis method for full-bridge LLC resonant converter | |
| CN117526724A (en) | Dynamic resonant frequency tracking method and system for full-bridge LLC resonant converter | |
| CN117254670A (en) | Optimal soft switch control method and system suitable for series resonant converter | |
| Baraneetharan et al. | Smart internet of things (IOT) system for performance improvement of dual bridge LLC resonant converter by using sophisticated distribution control method (SDC) | |
| CN109194135A (en) | A kind of adaptive efficiency optimization method of resonant state adjustable type power inverter | |
| Zhang et al. | Comparative study on predictive dead-beat peak current, valley current and average current control algorithms for phase-shifted full-bridge DC/DC converters | |
| KR20220131216A (en) | Resonant converter and control method of variable limit frequency thereof | |
| CN113708641A (en) | Synchronous rectification method and device for CLLC type DCDC converter | |
| Ma et al. | Small-signal modeling of the LLC half-bridge resonant converter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |