CN114583972B - Resonant converter, control method and device thereof, and power supply equipment - Google Patents

Resonant converter, control method and device thereof, and power supply equipment Download PDF

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Publication number
CN114583972B
CN114583972B CN202210484587.2A CN202210484587A CN114583972B CN 114583972 B CN114583972 B CN 114583972B CN 202210484587 A CN202210484587 A CN 202210484587A CN 114583972 B CN114583972 B CN 114583972B
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switching
tube
switch
switching tube
bridge
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CN114583972A (en
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杨帅
东伟
盛琳
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Meraki Integrated Shenzhen Technology Co ltd
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Meraki Integrated Shenzhen Technology Co ltd
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    • 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
    • H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
    • H02M1/083—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the ignition at the zero crossing of the voltage or the current
    • 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
    • H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
    • H02M1/088—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the simultaneous control of series or parallel connected semiconductor devices
    • 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
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
    • H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
    • H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/53—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/537—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters
    • H02M7/5387—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
    • H02M7/53871—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current
    • 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

Abstract

The application is applicable to the technical field of electronic circuits, and provides a resonant converter, a control method and a control device thereof, and power supply equipment, wherein a switching circuit comprises a full-bridge switching unit and a half-bridge auxiliary switching unit, and a transformation circuit comprises a first transformer and a second transformer; the first output end and the second output end of the full-bridge switch unit are respectively connected with the first input end and the second input end of the transformation circuit, the output end of the half-bridge auxiliary switch unit is connected with the third input end of the transformation circuit, the homonymous ends of primary coils of the first transformer and the second transformer are respectively the first input end and the third input end of the transformation circuit, and the synonym end of the primary coil of the first transformer and the synonym end of the primary coil of the second transformer are connected together to be used as the second input end of the transformation circuit; the control device is used for controlling the on-off of the switching circuit based on a target switch control strategy corresponding to the target gain, so that the switching tube can realize soft switching when being switched on and switched off, and the control device can be used in a wide output voltage range scene.

Description

Resonant converter, control method and device thereof, and power supply equipment
Technical Field
The application belongs to the technical field of electronic circuits, and particularly relates to a resonant converter, a control method and a control device of the resonant converter, and power supply equipment.
Background
A resonant converter is a voltage conversion device that achieves output voltage regulation by adjusting the switching frequency. The conventional resonant converter can enable a switching tube to realize Zero Voltage Switch (ZVS) function by adjusting the on-off duration of the switching tube in the switching circuit. However, the conventional resonant converter can only realize the ZVS function, and cannot realize a zero current switch (zero current switch) function, so that a switching tube has a large turn-off loss, and the power conversion efficiency of the resonant converter is reduced as a whole.
In order to improve the power conversion efficiency of the resonant converter, the switching frequency of the resonant converter is conventionally fixed near the resonant frequency of the resonant circuit, or the inductive reactance of the excitation inductor of the transformer is increased, so that the switching tube operates in a Zero Voltage Zero Current Switch (ZVZCS) state.
Disclosure of Invention
In view of this, embodiments of the present application provide a resonant converter, a control method and an apparatus thereof, and a power supply device, so as to solve a technical problem that a conventional resonant converter capable of operating in a state close to a ZVZCS cannot be applied to a wide output voltage range scenario, which limits an application scenario of the resonant converter.
In a first aspect, an embodiment of the present application provides a resonant converter, which includes a switching circuit, a resonant circuit, a voltage transformation circuit, and a rectification output circuit, which are sequentially disposed between an input end and an output end of the resonant converter, where the switching circuit is connected to a control device of the resonant converter; the switching circuit comprises a full-bridge switching unit and a half-bridge auxiliary switching unit; the transformation circuit comprises a first transformer and a second transformer;
the first input end of the full-bridge switch unit and the first input end of the half-bridge auxiliary switch unit are connected to the positive electrode of a direct-current power supply in a common mode, the second input end of the full-bridge switch unit and the second input end of the half-bridge auxiliary switch unit are connected to the negative electrode of the direct-current power supply in a common mode, the first output end of the full-bridge switch unit is connected to the first input end of the transformation circuit through the resonance circuit, the second output end of the full-bridge switch unit is connected to the second input end of the transformation circuit, and the output end of the half-bridge auxiliary switch unit is connected to the third input end of the transformation circuit;
the homonymous end of the primary coil of the first transformer is a first input end of the transformation circuit, the heteronymous end of the primary coil of the first transformer and the heteronymous end of the primary coil of the second transformer are connected in common and serve as a second input end of the transformation circuit, the homonymous end of the primary coil of the second transformer is a third input end of the transformation circuit, the homonymous end of the secondary coil of the first transformer is connected with the first input end of the rectification output circuit, the heteronymous end of the secondary coil of the first transformer is connected with the homonymous end of the secondary coil of the second transformer, and the heteronymous end of the secondary coil of the second transformer is connected with the second input end of the rectification output circuit; the output end of the rectification output circuit is used for connecting a load;
the control device is used for controlling the on-off of the full-bridge switch unit and the half-bridge auxiliary switch unit based on a target switch control strategy corresponding to a target gain, so that the switch tubes in the switch circuit can realize a soft switching function when being switched on and switched off.
In an optional implementation manner of the first aspect, the full-bridge switch unit includes a first switch tube, a second switch tube, a third switch tube, and a fourth switch tube;
the first conducting end of the first switch tube and the first conducting end of the third switch tube are connected in common and serve as a first input end of the full-bridge switch unit, the second conducting end of the second switch tube and the second conducting end of the fourth switch tube are connected in common and serve as a second input end of the full-bridge switch unit, the second conducting end of the third switch tube and the first conducting end of the fourth switch tube are connected in common and serve as a first output end of the full-bridge switch unit, the second conducting end of the first switch tube and the first conducting end of the second switch tube are connected in common and serve as a second output end of the full-bridge switch unit, and the controlled end of the first switch tube, the controlled end of the second switch tube, the controlled end of the third switch tube and the controlled end of the fourth switch tube are connected with the control device.
In an optional implementation manner of the first aspect, the half-bridge auxiliary switching unit includes a fifth switching tube and a sixth switching tube;
the first end that switches on of fifth switch tube is as the first input of half-bridge auxiliary switch unit, the second of sixth switch tube switches on the end as the second input of half-bridge auxiliary switch unit, the second of fifth switch tube switch on the end with the first end of sixth switch tube connects in common and as the output of half-bridge auxiliary switch unit, the controlled end of fifth switch tube with the controlled end of sixth switch tube all connects controlling means.
In a second aspect, an embodiment of the present application provides a control method for a resonant converter, where the control method is applied to the resonant converter according to the first aspect or any optional manner of the first aspect, and the control method includes:
determining a desired target gain;
and determining a target switch control strategy corresponding to the target gain, and controlling the on-off of the full-bridge switch unit and the half-bridge auxiliary switch unit based on the target switch control strategy.
In an optional implementation manner of the second aspect, the determining a target switch control strategy corresponding to the target gain, and performing on-off control on the full-bridge switch unit and the half-bridge auxiliary switch unit based on the target switch control strategy includes:
if the target gain is greater than a first gain threshold and less than or equal to 1, controlling a first switch group and a second switch group in the full-bridge switch unit to be alternately switched on based on a first preset duty ratio, and controlling a sixth switch tube and a fifth switch tube in the half-bridge auxiliary switch unit to be alternately switched on based on a second preset duty ratio; based on the target gain and a preset corresponding relation between the gain and the switching frequency, adjusting the switching frequency of each switching tube in the first switching group, the switching frequency of each switching tube in the second switching group, the switching frequency of the fifth switching tube and the switching frequency of the sixth switching tube;
after the switching frequency of each switching tube is adjusted to the highest switching frequency, reducing the duty ratio of the fifth switching tube and the duty ratio of the sixth switching tube until the duty ratios of the fifth switching tube and the sixth switching tube are reduced to 0, and controlling the first switching group and the second switching group to be alternately switched on only based on the first preset duty ratio;
the first switch group comprises a first switch tube and a fourth switch tube, and the second switch group comprises a second switch tube and a third switch tube; the second preset duty cycle is less than the first preset duty cycle.
In an optional implementation manner of the second aspect, the determining a target switch control strategy corresponding to the target gain, and performing on-off control on the full-bridge switch unit and the half-bridge auxiliary switch unit based on the target switch control strategy further includes:
if the target gain is larger than a second gain threshold and smaller than or equal to the first gain threshold, controlling the first switch group and the second switch group to be alternately switched on and controlling the fifth switch tube and the sixth switch tube to be continuously switched off based on the first preset duty ratio; based on the target gain and a preset corresponding relation between the gain and the switching frequency, adjusting the switching frequency of the first switching tube, the switching frequency of the second switching tube, the switching frequency of the third switching tube and the switching frequency of the fourth switching tube;
after the switching frequency of the first switching tube, the switching frequency of the second switching tube, the switching frequency of the third switching tube and the switching frequency of the fourth switching tube are all adjusted to the highest switching frequency, the duty ratio of the first switching tube and the duty ratio of the second switching tube are kept unchanged, the duty ratio of the third switching tube is reduced, the duty ratio of the fourth switching tube is increased, and after the duty ratio of the third switching tube is reduced to 0, the first switching tube and the second switching tube are controlled to be alternately conducted only based on the first preset duty ratio.
In an optional implementation manner of the second aspect, the determining a target switch control strategy corresponding to the target gain, and performing on-off control on the full-bridge switch unit and the half-bridge auxiliary switch unit based on the target switch control strategy further includes:
if the target gain is larger than a third gain threshold and smaller than or equal to the second gain threshold, controlling the first switching tube and the second switching tube to be alternately switched on based on the first preset duty ratio, controlling the fourth switching tube, the fifth switching tube and the sixth switching tube to be continuously switched off, and controlling the third switching tube to be continuously switched on; adjusting the switching frequency of the first switching tube and the switching frequency of the second switching tube based on the target gain and the preset corresponding relation between the gain and the switching frequency;
after the switching frequency of the first switching tube and the switching frequency of the second switching tube are adjusted to the highest switching frequency, the duty ratio of the first switching tube and the duty ratio of the second switching tube are adjusted based on the target gain.
In an optional implementation manner of the second aspect, the determining a target switch control strategy corresponding to the target gain, and performing on-off control on the full-bridge switch unit and the half-bridge auxiliary switch unit based on the target switch control strategy further includes:
if the target gain is smaller than or equal to a third gain threshold, setting the switching frequency of the first switching tube and the switching frequency of the second switching tube to be the highest switching frequency, controlling the first switching tube and the second switching tube to be alternately switched on, controlling the fourth switching tube, the fifth switching tube and the sixth switching tube to be continuously switched off, and controlling the third switching tube to be continuously switched on; and adjusting the duty ratio of the first switching tube and the duty ratio of the second switching tube based on the target gain.
In a third aspect, embodiments of the present application provide a control device for a resonant converter, where the control device is configured to execute the control method according to the second aspect or any optional manner of the second aspect.
In a fourth aspect, embodiments of the present application provide a power supply apparatus, including a dc power supply, a resonant converter as described in the first aspect or any optional manner of the first aspect, and a control device as described in the third aspect, where the resonant converter is connected to the dc power supply and the control device.
The resonant converter, the control method and the control device thereof and the power supply equipment provided by the embodiment of the application have the following beneficial effects:
in the resonant converter provided in the embodiment of the present application, the switching circuit includes a full-bridge switching unit and a half-bridge auxiliary switching unit, and the transforming circuit includes a first transformer and a second transformer; and a first output end of the full-bridge switch unit is connected to a first input end of the transformation circuit through the resonance circuit, a second output end of the full-bridge switch unit is connected to a second input end of the transformation circuit, an output end of the half-bridge auxiliary switch unit is connected to a third input end of the transformation circuit, a dotted terminal of a primary coil of the first transformer and a dotted terminal of a primary coil of the second transformer are respectively the first input end and the third input end of the transformation circuit, and a dotted terminal of the primary coil of the first transformer and a dotted terminal of the primary coil of the second transformer are connected together as the second input end of the transformation circuit. Because any target gain corresponds to a target switch control strategy which can enable the switch tube to realize the soft switching function when the switch tube is switched on and switched off, the control device controls the on-off of the switch circuit based on the target switch control strategy corresponding to the target gain, the switch tube in the resonant converter can realize the soft switching function when the switch tube is switched on and switched off, the electric energy conversion efficiency of the resonant converter is improved, and the gain of the resonant converter can be adjusted at will, so that the resonant converter has a wider output voltage range, and the application scene of the resonant converter is expanded.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the embodiments or the prior art description will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings may be obtained according to these drawings without inventive labor.
Fig. 1 is a schematic structural diagram of a resonant converter according to an embodiment of the present disclosure;
fig. 2 is a schematic diagram illustrating a waveform change of a resonant current according to an embodiment of the present disclosure;
fig. 3 is a schematic flowchart of a control method of a resonant converter according to an embodiment of the present application;
fig. 4 is a schematic structural diagram of a control apparatus of a resonant converter according to an embodiment of the present disclosure;
fig. 5 is a schematic structural diagram of a power supply device according to an embodiment of the present application.
Detailed Description
It is noted that the terminology used in the description of the embodiments of the present application is for the purpose of describing particular embodiments of the present application only and is not intended to be limiting of the present application. In the description of the embodiments of the present application, "/" indicates an alternative meaning, for example, a/B may indicate a or B; "and/or" herein is merely an associative relationship describing an association, meaning that there may be three relationships, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present application, "a plurality" means two or more, and "at least one", "one or more" means one, two or more, unless otherwise specified.
In the following, the terms "first", "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a definition of "a first" or "a second" feature may explicitly or implicitly include one or more of the features.
Reference throughout this specification to "one embodiment" or "some embodiments," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," or the like, in various places throughout this specification are not necessarily all referring to the same embodiment, but rather "one or more but not all embodiments" unless specifically stated otherwise. The terms "comprising," "including," "having," and variations thereof mean "including, but not limited to," unless expressly specified otherwise.
A resonant converter is a voltage conversion device that achieves output voltage regulation by adjusting the switching frequency. Generally, according to the number of switching tubes in the switching circuit of the resonant converter, the resonant converter can be divided into a half-bridge resonant converter (i.e., the switching circuit is a half-bridge switching circuit composed of two switching tubes) and a full-bridge resonant converter (i.e., the switching circuit is a full-bridge switching circuit composed of four switching tubes), where the half-bridge resonant converter is generally applicable to a small-power scenario and the full-bridge resonant converter is generally applicable to a large-power scenario.
The conventional half-bridge resonant converter and the conventional full-bridge resonant converter can realize Zero Voltage Switch (ZVS) function by adjusting the on-off duration of a switch tube in a switch circuit, and the conduction loss of the switch tube is reduced. However, the conventional resonant converter can only realize the ZVS function, and a switching tube in a switching circuit of the resonant converter is usually turned off hard because the current is usually large when the switching tube is turned off, and cannot realize a zero current switching (zero current switch) function, so that the switching tube has a large turn-off loss, which generally reduces the power conversion efficiency of the resonant converter.
In order to improve the power conversion efficiency of the resonant converter, the switching frequency of the resonant converter is fixed near the resonant frequency of the resonant circuit, or the inductive reactance of the excitation inductor of the transformer is increased, so that the switching tube operates in a Zero Voltage Zero Current Switch (ZVZCS) state, thereby reducing the switching loss of the switching tube. However, if the switching frequency of the resonant converter is fixed near the resonant frequency, the gain of the resonant converter cannot be adjusted, and the output voltage of the resonant converter cannot be adjusted, which limits the application scenarios of the resonant converter. By connecting a direct current-direct current (DC-DC) converter in series in the conventional resonant converter, the output voltage of the resonant converter can be adjusted, but the complexity and cost of the resonant converter are increased.
Therefore, the traditional resonant converter capable of working in a state close to the ZVZCS state cannot be applied to a scene with a wide output voltage range, so that the application scene of the resonant converter is limited; the resonant converter circuit capable of working in a state close to the ZVZCS and realizing output voltage regulation is complex and high in cost.
Based on this, the embodiment of the present application firstly provides a resonant converter, which may be a dc-dc resonant converter. In a specific application, the resonant converter may be connected to a control device of the resonant converter. By way of example and not limitation, the control means of the resonant converter may include a Pulse Width Modulation (PWM) and a Pulse Frequency Modulation (PFM). PWM can be used to adjust the duty cycle of the switching tubes in the resonant converter and PFM can be used to adjust the switching frequency of the switching tubes in the resonant converter.
Fig. 1 is a schematic structural diagram of a resonant converter according to an embodiment of the present disclosure. As shown in fig. 1, the resonant converter may include a switching circuit 11, a resonant circuit 12, a transforming circuit 13, and a rectifying output circuit 14, which are sequentially disposed between an input terminal and an output terminal of the resonant converter.
Specifically, the switching circuit 11 may include a full-bridge switching cell 111 and a half-bridge auxiliary switching cell 112.
Wherein, the first input of full-bridge switch unit 111 and the first input of half-bridge auxiliary switch unit 112 connect in direct current power supply DC's positive pole altogether, the second input of full-bridge switch unit 111 and the second input of half-bridge auxiliary switch unit 112 connect in direct current power supply DC's negative pole altogether, the first output of full-bridge switch unit 111 is connected to the first input of vary voltage circuit 13 through resonant circuit 12, the second input of vary voltage circuit 13 is connected to the second output of full-bridge switch unit 111, the third input of vary voltage circuit 13 is connected to the output of half-bridge auxiliary switch unit 12.
The full-bridge switching unit 111 may include a first switching tube Q1, a second switching tube Q2, a third switching tube Q3, and a fourth switching tube Q4. The first conducting terminal of the first switch tube Q1 and the first conducting terminal of the third switch tube Q3 are connected in common and serve as the first input terminal of the full-bridge switch unit 111, the second conducting terminal of the second switch tube Q2 and the second conducting terminal of the fourth switch tube Q4 are connected in common and serve as the second input terminal of the full-bridge switch unit 111, the second conducting terminal of the third switch tube Q3 and the first conducting terminal of the fourth switch tube Q4 are connected in common and serve as the first output terminal of the full-bridge switch unit 111, and the second conducting terminal of the first switch tube Q1 and the first conducting terminal of the second switch tube Q2 are connected in common and serve as the second output terminal of the full-bridge switch unit 111. The controlled end of the first switch tube Q1, the controlled end of the second switch tube Q2, the controlled end of the third switch tube Q3 and the controlled end of the fourth switch tube Q4 are all connected to PWM and PFM in the control device.
The half-bridge auxiliary switching unit 112 may include a fifth switching tube Q5 and a sixth switching tube Q6. A first conduction terminal of the fifth switch tube Q5 is used as a first input terminal of the half-bridge auxiliary switch unit 112, a second conduction terminal of the sixth switch tube Q6 is used as a second input terminal of the half-bridge auxiliary switch unit 112, and a second conduction terminal of the fifth switch tube Q5 is connected in common with the first conduction terminal of the sixth switch tube Q6 and is used as an output terminal of the half-bridge auxiliary switch unit 112. The controlled end of the fifth switch tube Q5 and the controlled end of the sixth switch tube Q6 are both connected with PWM and PFM in the control device.
By way of example and not limitation, the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, the fourth switch tube Q4, the fifth switch tube Q5, and the sixth switch tube Q6 may be metal-oxide-semiconductor field-effect transistors (MOSFETs), triodes, or the like, and are specifically set according to actual requirements, and the type of each switch tube is not particularly limited herein.
Specifically, the resonant circuit 12 may include a resonant inductance Lr and a resonant capacitance Cr.
The first end of the resonant inductor Cr is a first end of the resonant circuit 12, the second end of the resonant inductor Cr is connected to the first end of the resonant inductor Lr, the second end of the resonant inductor Lr is a second end of the resonant circuit 12, the first end of the resonant circuit 12 is connected to the first output end of the full-bridge switching unit 111, and the second end of the resonant circuit 12 is connected to the first input end of the transformer circuit 13.
Specifically, the transforming circuit 13 may include a first transformer Tr1 and a second transformer Tr 2.
The dotted terminal of the primary coil of the first transformer Tr1 is a first input terminal of the transformer circuit 13, the dotted terminal of the primary coil of the first transformer Tr1 and the dotted terminal of the primary coil of the second transformer Tr2 are connected in common and serve as a second input terminal of the transformer circuit 13, the dotted terminal of the primary coil of the second transformer Tr2 is a third input terminal of the transformer circuit 13, the dotted terminal of the secondary coil of the first transformer Tr1 is connected to the first input terminal of the rectifier output circuit 14, the dotted terminal of the secondary coil of the first transformer Tr1 is connected to the dotted terminal of the secondary coil of the second transformer Tr2, and the dotted terminal of the secondary coil of the second transformer Tr2 is connected to the second input terminal of the rectifier output circuit 14. The output of the rectified output circuit 14 is used to connect a load.
In the embodiment of the present application, the turn ratio of the first transformer Tr1 may be N1 × Vin/Vout, and the turn ratio of the second transformer Tr2 may be N2 × Vin/Vout, where Vin is an input voltage of the resonant converter (i.e., an output voltage of the DC power supply DC), Vout is an output voltage of the resonant converter, and N1+ N2= 1.
It should be noted that both N1 and N2 may be set according to actual requirements, and are not particularly limited herein. Illustratively, both N1 and N2 may be 0.5, in which case the output voltage of the first transformer Tr1 and the output voltage of the second transformer Tr2 are both half of the output voltage of the resonant converter.
Specifically, the rectified output circuit 14 may include a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, and an output capacitor C1.
An anode of the first diode D1 and a cathode of the second diode are connected in common and serve as a first input end of the rectification output circuit 14, an anode of the third diode D3 and a cathode of the fourth diode D4 are connected in common and serve as a second input end of the rectification output circuit 14, a cathode of the first diode D1, a cathode of the third diode D3 and a first end of the output capacitor C1 are connected in common and serve as a first output end of the rectification output circuit 14, and an anode of the second diode D2, an anode of the fourth diode D4 and a second end of the output capacitor C1 are connected in common and serve as a second output end of the rectification output circuit 14. A load, such as a resistor, may be connected between the first output terminal and the second output terminal of the rectified output circuit 14.
The following describes the operating principle of the resonant converter provided in the embodiments of the present application in detail:
referring to fig. 2, when the first switch Q1, the fourth switch Q4, and the sixth switch Q6 are turned on at the same time, and the second switch Q2, the third switch Q3, and the fifth switch Q5 are all turned off (i.e., the time period 0-t 1 in fig. 2), a current flows from the positive electrode of the DC power supply DC, and flows back to the negative electrode of the DC power supply DC through the first switch Q1, the first transformer Tr1, the resonant circuit 12, and the fourth switch Q4; the other current flows from the positive electrode of the DC power supply DC, and flows back to the negative electrode of the DC power supply DC after passing through the first switching tube Q1, the second transformer Tr2, and the sixth switching tube Q6, that is, the two currents in this case flow out from the dotted terminal of the primary coil of the first transformer Tr1 and the dotted terminal of the primary coil of the second transformer Tr2, respectively, and at this time, the current in the resonant circuit 12 flows from the second terminal of the resonant circuit 12 to the first terminal of the resonant circuit 12. Since the secondary coil of the first transformer Tr1 and the secondary coil of the second transformer Tr2 are connected in series, currents having the same direction and the same amplitude flow through the secondary coil of the first transformer Tr1 and the secondary coil of the second transformer Tr 2.
On the basis of the above, when the sixth switching tube Q6 is turned off (i.e. the time period from t1 to t2 in fig. 2), the current flowing from the same-name end of the primary winding of the second transformer Tr2 flows to the positive electrode of the DC power supply DC or the first switching tube Q1 via the body diode of the fifth switching tube Q5, so that the voltage across the primary winding of the second transformer Tr2 is reduced to 0, and since the secondary winding of the first transformer 1 and the secondary winding of the second transformer Tr2 are in series connection, in order to keep the secondary current of the transformer constant, a resonant circuit 12 is generated when the resonant circuit is conducted with the sixth switching tube Q6The voltage across the inductor Lr is increased from N1 Vout to Vout by the voltage across the primary winding of the first transformer Tr1 being opposite in direction, and even if the voltage across the primary winding of the first transformer Tr1 is increased by N2 Vout, the resonant current I is increased by the generation of this reverse voltage Lr Can make the resonant current I fall Lr When the first switching tube Q1 and the fourth switching tube Q4 are turned off, the voltage drops to 0 or close to 0, so that the first switching tube Q1 and the fourth switching tube Q4 realize the ZCS function. It should be noted that the control principles of the second switching tube Q2, the third switching tube Q3 and the fifth switching tube Q5 are similar, and are not described herein again.
It can be seen that, in one switching cycle, when the first switching tube Q1, the fourth switching tube Q4, and the sixth switching tube Q6 (or the second switching tube Q2, the third switching tube Q3, and the fifth switching tube Q5) are turned on at the same time, the sixth switching tube Q6 (or the fifth switching tube Q5) may be turned off in advance to increase the speed of decreasing the resonant current, that is, the duty ratio of the sixth switching tube Q6 (or the fifth switching tube Q5) may be set to be smaller than the duty ratios of the first switching tube Q1 and the fourth switching tube Q4, so that the resonant current may decrease to 0 or close to 0 before the first switching tube Q1 and the fourth switching tube Q4 (or the second switching tube Q2 and the third switching tube Q3) are turned off, and the first switching tube Q1 and the fourth switching tube Q4 (or the second switching tube Q2 and the third switching tube Q4) may further realize the ZCS 3 function.
It should be noted that, the ZVS function of each switching tube is realized based on the excitation current of the resonant converter, which is an inherent characteristic of the resonant converter structure and does not belong to the invention point of the present application, so the embodiment of the present application does not describe much the implementation manner of the ZVS function of the switching tube.
On the basis, in order to enable the resonant converter to realize the ZCS and/or ZVS function and have a wide output voltage range, the gain of the resonant converter which may be involved may be divided into a plurality of gain ranges in advance, and a corresponding switching control strategy may be configured for each gain range. In this way, the control apparatus of the resonant converter can perform on-off control on the full-bridge switching unit 111 and the half-bridge auxiliary switching unit 112 based on a target switching control strategy corresponding to a desired (i.e. required by a practical application scenario) target gain, so that the switching tubes in the switching circuit 11 realize a soft switching function when being turned on and off.
For example, the preset gain ranges and their corresponding switch control strategies may be as follows:
(1) gain range (0.5,1], the corresponding switch control strategy may be:
the first switch group and the second switch group are controlled to be alternately conducted based on a first preset duty ratio, and the sixth switch tube Q6 and the fifth switch tube Q5 are controlled to be alternately conducted based on a second preset duty ratio; based on the target gain and the preset corresponding relation between the gain and the switching frequency, the switching frequency of the first switching tube Q1, the switching frequency of the second switching tube Q2, the switching frequency of the third switching tube Q3, the switching frequency of the fourth switching tube Q4, the switching frequency of the fifth switching tube Q5 and the switching frequency of the sixth switching tube Q6 are adjusted;
after the switching frequencies of the switching tubes (i.e., the first switching tube Q1 to the sixth switching tube Q6) are all adjusted to the highest switching frequency, the duty ratio of the fifth switching tube Q5 and the duty ratio of the sixth switching tube Q6 are reduced until the duty ratio of the fifth switching tube Q5 and the duty ratio of the sixth switching tube Q6 are reduced to 0, and then the first switching group and the second switching group are controlled to be alternately switched on only based on the first preset duty ratio.
The second preset duty cycle is smaller than the first preset duty cycle, and for example, the first preset duty cycle may be 50% and the second preset duty cycle may be 45%.
The first switch group comprises a first switch tube Q1 and a fourth switch tube Q4, and the second switch group comprises a second switch tube Q2 and a third switch tube Q3.
The highest switching frequency may be equal to the resonant frequency of the resonant circuit 12.
It should be noted that, the two (or two) groups of switching tubes are alternately turned on, and when one (or one) group of switching tubes is turned on, the other (or the other) group of switching tubes is turned off. For example, the sixth switching tube Q6 and the fifth switching tube Q5 are controlled to be alternately turned on, and the sixth switching tube Q6 is controlled to be turned on, and the fifth switching tube Q5 is controlled to be turned off; the sixth switching tube Q6 is controlled to be turned off, and the fifth switching tube Q5 is controlled to be turned on. In a specific application, when the two (or two) groups of switching tubes are controlled to be alternately conducted, dead time can be inserted into the alternating gaps, and in the dead time, the two (or two) groups of switching tubes are both turned off.
In the embodiment of the present application, when the first switch group and the second switch group are controlled to be alternately turned on, and the sixth switch Q6 and the fifth switch Q5 are controlled to be alternately turned on, the specific turn-on timing of the sixth switch Q6 and the fifth switch Q5 is that the sixth switch Q6 is controlled to be turned on while the first switch group is controlled to be turned on; and the fifth switch tube Q5 is controlled to be conducted at the same time of controlling the second switch group to be conducted.
(2) Gain range (0.25,0.5], corresponding switch control strategy may be:
the first switch group and the second switch group are controlled to be alternately switched on based on a first preset duty ratio, and the fifth switch tube Q5 and the sixth switch tube Q6 are controlled to be continuously switched off; based on the target gain and the preset corresponding relation between the gain and the switching frequency, the switching frequency of the first switching tube Q1, the switching frequency of the second switching tube Q2, the switching frequency of the third switching tube Q3 and the switching frequency of the fourth switching tube Q4 are adjusted;
after the switching frequency of the first switching tube Q1, the switching frequency of the second switching tube Q2, the switching frequency of the third switching tube Q3 and the switching frequency of the fourth switching tube Q4 are all adjusted to the highest switching frequency, the duty cycle of the first switching tube Q1 and the duty cycle of the second switching tube Q2 are kept unchanged, the duty cycle of the third switching tube Q3 is reduced, and the duty cycle of the fourth switching tube Q4 is increased; after the duty ratio of the third switching tube Q3 is reduced to 0, the first switching tube Q1 and the second switching tube Q2 are controlled to be alternately turned on based on only the first preset duty ratio.
(3) Gain range (0.15,0.25], corresponding switch control strategy may be:
the method comprises the steps that a first switching tube Q1 and a second switching tube Q2 are controlled to be alternately conducted based on a first preset duty ratio, a fourth switching tube Q4, a fifth switching tube Q5 and a sixth switching tube Q6 are controlled to be continuously turned off, and a third switching tube Q3 is controlled to be continuously conducted; based on the target gain and the preset corresponding relation between the gain and the switching frequency, the switching frequency of the first switching tube Q1 and the switching frequency of the second switching tube Q2 are adjusted;
after the switching frequency of the first switching tube Q1 and the switching frequency of the second switching tube Q2 are both adjusted to the highest switching frequency, the duty cycle of the first switching tube Q1 and the duty cycle of the second switching tube Q2 are adjusted based on the target gain.
(4) Gain range (0,0.15], the corresponding switch control strategy may be:
setting the switching frequency of the first switching tube Q1 and the switching frequency of the second switching tube Q2 to be the highest switching frequency, controlling the first switching tube Q1 and the second switching tube Q2 to be alternately switched on, controlling the fourth switching tube Q4, the fifth switching tube Q5 and the sixth switching tube Q6 to be continuously switched off, and controlling the third switching tube Q3 to be continuously switched on; based on the target gain, the duty cycle of the first switching tube Q1 and the duty cycle of the second switching tube Q2 are adjusted, and the duty cycle of the first switching tube Q1 is decreased, and the duty cycle of the second switching tube Q2 is increased.
Based on this, the control device of the resonant converter may determine a desired target gain, determine a target gain range to which the target gain belongs, and perform on-off control on the full-bridge switch unit 111 and the half-bridge auxiliary switch unit 112 based on a target switch control strategy corresponding to the target gain range. It should be noted that, the switching control strategy corresponding to each gain range is as described above, and is not described herein again.
As can be seen from the above, when the resonant converter is connected to a medium-high power load (that is, the gain range of the resonant converter is (0.5, 1)), the duty ratio of each switching tube in the half-bridge auxiliary switching unit is first fixed to a second preset duty ratio (for example, 0.45), that is, the duty ratio of each switching tube in the half-bridge auxiliary switching unit is not adjusted based on the target gain, but the switching frequency of the first switching tube to the sixth switching tube is adjusted to make the resonant converter reach the target gain.
Specifically, when the target gain is less than or equal to 0.5, the duty ratio of each switching tube in the half-bridge auxiliary switching unit is set to 0, and the half-bridge auxiliary switching unit is turned off, so that only the full-bridge switching unit is operated, in which case only the first transformer has an output voltage and the second transformer has an output voltage of 0, so that by designing the turn ratio of the first transformer and the turn ratio of the second transformer to be 0.5 × Vin/Vout, the gain of the resonant converter can be directly reduced to 0.5, and then by adjusting the duty ratio or the switching frequency of each switching tube in the full-bridge switching unit, the target gain coverage gain range is (0, 0.5), and through the control, each switching tube in the resonant converter can realize the ZVZCS function, the resonant converter has a wider output voltage range, and the application scene of the resonant converter is expanded.
In addition, the rectification output circuit of the resonant converter provided by the embodiment of the application adopts a full-bridge rectification structure formed by four diodes, so that the diodes can realize the ZCS function, the electric energy loss on the rectification output circuit is reduced, and the electric energy conversion efficiency of the resonant converter is improved as a whole.
In addition, because the resonant converter provided by the embodiment of the application is only additionally provided with the half-bridge auxiliary switch unit and the second transformer on the basis of the traditional full-bridge resonant converter, and the output power of the resonant converter is shared by the additionally arranged half-bridge auxiliary switch unit and the second transformer, compared with the scheme that the traditional full-bridge resonant converter is connected with the DC-DC converter in series, the cost of realizing the ZVZCS function of the resonant converter and the thermal stress of each component are reduced, and the complexity and the size of the resonant converter are reduced.
Based on the resonant converter provided by the above embodiment, the embodiment of the present application further provides a control method for the resonant converter, and the control method can be applied to a control device of the resonant converter. Fig. 3 is a schematic flowchart of a control method of a resonant converter according to an embodiment of the present disclosure. As shown in FIG. 3, the control method of the resonant converter may include steps S31-S32, which are detailed as follows:
s31: a desired target gain is determined.
In the embodiment of the application, the target gain is positively correlated with the load capacity of the load. Generally, the larger the load of the load, the larger the target gain of the resonant converter is required; the smaller the load capacity of the load, the smaller the target gain of the resonant converter is required. Based on this, a target gain of the resonant converter may be determined according to the load capacity of the load.
S32: and determining a target switch control strategy corresponding to the target gain, and controlling the on-off of the full-bridge switch unit and the half-bridge auxiliary switch unit based on the target switch control strategy.
In this embodiment, a gain range to which the target gain belongs may be determined first, and the switching control strategy corresponding to the gain range to which the target gain belongs may be determined as the target switching control strategy.
In one embodiment of the present application, S32 may include the steps of:
if the target gain is larger than the first gain threshold and smaller than or equal to 1, controlling the first switch group and the second switch group to be alternately switched on based on a first preset duty ratio, and controlling the sixth switch tube Q6 and the fifth switch tube Q5 to be alternately switched on based on a second preset duty ratio; based on the target gain and the preset corresponding relation between the gain and the switching frequency, the switching frequency of the first switching tube Q1, the switching frequency of the second switching tube Q2, the switching frequency of the third switching tube Q3, the switching frequency of the fourth switching tube Q4, the switching frequency of the fifth switching tube Q5 and the switching frequency of the sixth switching tube Q6 are adjusted;
after the switching frequency of each switching tube is adjusted to the highest switching frequency, the duty ratio of the fifth switching tube Q5 and the duty ratio of the sixth switching tube Q6 are reduced until the duty ratio of the fifth switching tube Q5 and the duty ratio of the sixth switching tube Q6 are reduced to 0, and then the first switching group and the second switching group are controlled to be alternately conducted only based on the first preset duty ratio.
It should be noted that please refer to the related description in the embodiment corresponding to fig. 1 for detailed description of the above steps, which is not repeated herein.
In another embodiment of the present application, S32 may further include the steps of:
if the target gain is greater than a second gain threshold and less than or equal to a first gain threshold, controlling the first switch group and the second switch group to be alternately switched on and controlling the fifth switch tube Q5 and the sixth switch tube Q6 to be continuously switched off based on a first preset duty ratio; based on the target gain and the preset corresponding relation between the gain and the switching frequency, the switching frequency of the first switching tube Q1, the switching frequency of the second switching tube Q2, the switching frequency of the third switching tube Q3 and the switching frequency of the fourth switching tube Q4 are adjusted;
after the switching frequency of the first switching tube Q1, the switching frequency of the second switching tube Q2, the switching frequency of the third switching tube Q3 and the switching frequency of the fourth switching tube Q4 are all adjusted to the highest switching frequency, the duty cycle of the first switching tube Q1 and the duty cycle of the second switching tube Q2 are kept unchanged, the duty cycle of the third switching tube Q3 is reduced, and the duty cycle of the fourth switching tube Q4 is increased; after the duty ratio of the third switching tube Q3 is reduced to 0, the first switching tube Q1 and the second switching tube Q2 are controlled to be alternately conducted only based on the first preset duty ratio.
In yet another embodiment of the present application, S32 may further include the steps of:
if the target gain is greater than a third gain threshold and less than or equal to a second gain threshold, controlling the first switching tube Q1 and the second switching tube Q2 to be alternately switched on based on a first preset duty ratio, controlling the fourth switching tube Q4, the fifth switching tube Q5 and the sixth switching tube Q6 to be continuously switched off, and controlling the third switching tube Q3 to be continuously switched on; based on the target gain and the preset corresponding relation between the gain and the switching frequency, the switching frequency of the first switching tube Q1 and the switching frequency of the second switching tube Q2 are adjusted;
after the switching frequency of the first switching tube Q1 and the switching frequency of the second switching tube Q2 are both adjusted to the highest switching frequency, the duty cycle of the first switching tube Q1 and the duty cycle of the second switching tube Q2 are adjusted based on the target gain.
In yet another embodiment of the present application, S32 may further include the steps of:
if the target gain is less than or equal to the third gain threshold, setting the switching frequency of the first switching tube Q1 and the switching frequency of the second switching tube Q2 to be the highest switching frequency, controlling the first switching tube Q1 and the second switching tube Q2 to be alternately switched on, controlling the fourth switching tube Q4, the fifth switching tube Q5 and the sixth switching tube Q6 to be continuously switched off, and controlling the third switching tube Q3 to be continuously switched on; based on the target gain, the duty cycle of the first switching tube Q1 and the duty cycle of the second switching tube Q2 are adjusted, and the duty cycle of the first switching tube Q1 is decreased, and the duty cycle of the second switching tube Q2 is increased.
Wherein the first gain threshold may be 0.5, the second gain threshold may be 0.25, and the third gain threshold may be 0.15.
It should be noted that, since the execution content corresponding to each step is based on the same concept as the execution content of the control device of the resonant converter in the previous embodiment of the present application, specific functions and technical effects thereof can be referred to the related description in the previous embodiment, and are not repeated herein.
The embodiment of the application further provides a control device of the resonant converter. Fig. 4 is a schematic structural diagram of a control device of a resonant converter according to an embodiment of the present disclosure. As shown in fig. 4, the control device 40 may include a pulse width modulator 41 and a pulse frequency modulator 42. The pulse width modulator 41 and the pulse frequency modulator 42 are each connected to a respective switching tube (not shown) in the resonant converter.
The control device 40 is used to execute the steps in the control method embodiment of the resonant converter.
Specifically, the pulse width modulator 41 is used for adjusting the duty ratio of each switching tube in the resonant converter, and the pulse frequency modulator 42 is used for adjusting the switching frequency of each switching tube in the resonant converter.
The embodiment of the application also provides power supply equipment. Fig. 5 is a schematic structural diagram of a power supply device according to an embodiment of the present disclosure. As shown in fig. 5, the power supply apparatus 50 may include a dc power supply 51, a resonant converter 52, and a control device 53. The resonant converter 52 is connected to a dc power supply 51 and a control device 53.
It should be noted that the resonant converter 52 in this embodiment may be the resonant converter in the embodiment corresponding to fig. 1, and the control device 53 may be the control device in the embodiment corresponding to fig. 4. For the content of the resonant converter 52, reference may be made to the description in the embodiment corresponding to fig. 1, and for the content of the control device 53, reference may be made to the description in the embodiment corresponding to fig. 4, which is not repeated herein.
In the above embodiments, the description of each embodiment has its own emphasis, and parts that are not described or illustrated in a certain embodiment may refer to the description of other embodiments.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims (9)

1. A resonant converter comprises a switching circuit, a resonant circuit, a voltage transformation circuit and a rectification output circuit which are sequentially arranged between an input end and an output end of the resonant converter, wherein the switching circuit is connected with a control device of the resonant converter; the switching circuit is characterized by comprising a full-bridge switching unit and a half-bridge auxiliary switching unit; the transformation circuit comprises a first transformer and a second transformer;
the first input end of the full-bridge switch unit and the first input end of the half-bridge auxiliary switch unit are connected to the positive electrode of a direct-current power supply in a common mode, the second input end of the full-bridge switch unit and the second input end of the half-bridge auxiliary switch unit are connected to the negative electrode of the direct-current power supply in a common mode, the first output end of the full-bridge switch unit is connected to the first input end of the transformation circuit through the resonance circuit, the second output end of the full-bridge switch unit is connected to the second input end of the transformation circuit, and the output end of the half-bridge auxiliary switch unit is connected to the third input end of the transformation circuit;
the homonymous end of the primary coil of the first transformer is a first input end of the transformation circuit, the heteronymous end of the primary coil of the first transformer and the heteronymous end of the primary coil of the second transformer are connected in common and serve as a second input end of the transformation circuit, the homonymous end of the primary coil of the second transformer is a third input end of the transformation circuit, the homonymous end of the secondary coil of the first transformer is connected with the first input end of the rectification output circuit, the heteronymous end of the secondary coil of the first transformer is connected with the homonymous end of the secondary coil of the second transformer, and the heteronymous end of the secondary coil of the second transformer is connected with the second input end of the rectification output circuit; the output end of the rectification output circuit is used for connecting a load;
the control device is used for controlling the on-off of the full-bridge switch unit and the half-bridge auxiliary switch unit based on a target switch control strategy corresponding to a target gain so as to enable a switch tube in the switch circuit to realize a soft switching function when the switch tube is switched on and switched off;
the control device is specifically configured to:
if the target gain is greater than a first gain threshold and less than or equal to 1, controlling a first switch group and a second switch group in the full-bridge switch unit to be alternately switched on based on a first preset duty ratio, and controlling a sixth switch tube and a fifth switch tube in the half-bridge auxiliary switch unit to be alternately switched on based on a second preset duty ratio; based on the target gain and a preset corresponding relation between the gain and the switching frequency, adjusting the switching frequency of each switching tube in the first switching group, the switching frequency of each switching tube in the second switching group, the switching frequency of the fifth switching tube and the switching frequency of the sixth switching tube;
after the switching frequency of each switching tube is adjusted to the highest switching frequency, reducing the duty ratio of the fifth switching tube and the duty ratio of the sixth switching tube until the duty ratios of the fifth switching tube and the sixth switching tube are reduced to 0, and then controlling the first switching group and the second switching group to be alternately switched on only based on the first preset duty ratio;
the first switch group comprises a first switch tube and a fourth switch tube, and the second switch group comprises a second switch tube and a third switch tube; the second preset duty cycle is less than the first preset duty cycle.
2. The resonant converter according to claim 1, wherein the full-bridge switching unit comprises a first switching tube, a second switching tube, a third switching tube and a fourth switching tube;
the first conducting end of the first switch tube and the first conducting end of the third switch tube are connected in common and serve as a first input end of the full-bridge switch unit, the second conducting end of the second switch tube and the second conducting end of the fourth switch tube are connected in common and serve as a second input end of the full-bridge switch unit, the second conducting end of the third switch tube and the first conducting end of the fourth switch tube are connected in common and serve as a first output end of the full-bridge switch unit, the second conducting end of the first switch tube and the first conducting end of the second switch tube are connected in common and serve as a second output end of the full-bridge switch unit, and the controlled end of the first switch tube, the controlled end of the second switch tube, the controlled end of the third switch tube and the controlled end of the fourth switch tube are connected with the control device.
3. The resonant converter of claim 1, wherein the half-bridge auxiliary switching unit comprises a fifth switching tube and a sixth switching tube;
the first end that switches on of fifth switch tube is regarded as the first input of half-bridge auxiliary switch unit, the second of sixth switch tube switches on the end as the second input of half-bridge auxiliary switch unit, the second of fifth switch tube switch on the end with the first end that switches on of sixth switch tube connects in common and regards as the output of half-bridge auxiliary switch unit, the controlled end of fifth switch tube with the controlled end of sixth switch tube all connects controlling means.
4. A control method of a resonant converter, applied to the resonant converter according to any one of claims 1 to 3, the control method comprising:
determining a desired target gain;
if the target gain is larger than a first gain threshold value and smaller than or equal to 1, controlling a first switch group and a second switch group in the full-bridge switch unit to be alternately switched on based on a first preset duty ratio, and controlling a sixth switch tube and a fifth switch tube in the half-bridge auxiliary switch unit to be alternately switched on based on a second preset duty ratio; based on the target gain and a preset corresponding relation between the gain and the switching frequency, adjusting the switching frequency of each switching tube in the first switching group, the switching frequency of each switching tube in the second switching group, the switching frequency of the fifth switching tube and the switching frequency of the sixth switching tube;
after the switching frequency of each switching tube is adjusted to the highest switching frequency, reducing the duty ratio of the fifth switching tube and the duty ratio of the sixth switching tube until the duty ratios of the fifth switching tube and the sixth switching tube are reduced to 0, and then controlling the first switching group and the second switching group to be alternately switched on only based on the first preset duty ratio;
the first switch group comprises a first switch tube and a fourth switch tube, and the second switch group comprises a second switch tube and a third switch tube; the second preset duty cycle is less than the first preset duty cycle.
5. The control method according to claim 4, wherein the determining a target switch control strategy corresponding to the target gain and controlling the full-bridge switch unit and the half-bridge auxiliary switch unit to be turned on and off based on the target switch control strategy further comprises:
if the target gain is larger than a second gain threshold and smaller than or equal to the first gain threshold, controlling the first switch group and the second switch group to be alternately switched on and controlling the fifth switch tube and the sixth switch tube to be continuously switched off based on the first preset duty ratio; based on the target gain and a preset corresponding relation between the gain and the switching frequency, adjusting the switching frequency of the first switching tube, the switching frequency of the second switching tube, the switching frequency of the third switching tube and the switching frequency of the fourth switching tube;
after the switching frequency of the first switching tube, the switching frequency of the second switching tube, the switching frequency of the third switching tube and the switching frequency of the fourth switching tube are all adjusted to the highest switching frequency, the duty ratio of the first switching tube and the duty ratio of the second switching tube are kept unchanged, the duty ratio of the third switching tube is reduced, the duty ratio of the fourth switching tube is increased, and after the duty ratio of the third switching tube is reduced to 0, the first switching tube and the second switching tube are controlled to be alternately conducted only based on the first preset duty ratio.
6. The control method according to claim 4, wherein the determining a target switch control strategy corresponding to the target gain and controlling the full-bridge switch unit and the half-bridge auxiliary switch unit to be turned on and off based on the target switch control strategy further comprises:
if the target gain is larger than a third gain threshold and smaller than or equal to a second gain threshold, controlling the first switching tube and the second switching tube to be alternately switched on based on the first preset duty ratio, controlling the fourth switching tube, the fifth switching tube and the sixth switching tube to be continuously switched off, and controlling the third switching tube to be continuously switched on; adjusting the switching frequency of the first switching tube and the switching frequency of the second switching tube based on the target gain and the preset corresponding relation between the gain and the switching frequency;
after the switching frequency of the first switching tube and the switching frequency of the second switching tube are adjusted to the highest switching frequency, the duty ratio of the first switching tube and the duty ratio of the second switching tube are adjusted based on the target gain.
7. The control method according to claim 4, wherein the determining a target switch control strategy corresponding to the target gain and controlling the full-bridge switch unit and the half-bridge auxiliary switch unit to be turned on and off based on the target switch control strategy further comprises:
if the target gain is smaller than or equal to a third gain threshold, setting the switching frequency of the first switching tube and the switching frequency of the second switching tube to be the highest switching frequency, controlling the first switching tube and the second switching tube to be alternately switched on, controlling the fourth switching tube, the fifth switching tube and the sixth switching tube to be continuously switched off, and controlling the third switching tube to be continuously switched on; and adjusting the duty ratio of the first switching tube and the duty ratio of the second switching tube based on the target gain.
8. A control device of a resonant converter, characterized in that the control device is configured to perform the control method of the resonant converter according to any one of claims 4 to 7.
9. A power supply apparatus, characterized by comprising a direct current power supply, a resonant converter according to any one of claims 1 to 3, and a control device according to claim 8, the resonant converter being connected to the direct current power supply and the control device.
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Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN212992651U (en) * 2020-09-27 2021-04-16 中山市金兴智能技术有限公司 Asymmetric half-bridge circuit and lighting system

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101938222B (en) * 2010-07-27 2014-02-05 Bcd半导体制造有限公司 Power supply device and backlight system for supplying backlight to display device
JP2017070083A (en) * 2015-09-30 2017-04-06 サンケン電気株式会社 Resonant bidirectional dc/dc converter
CN105576983B (en) * 2016-02-19 2019-06-04 杭州中恒电气股份有限公司 A kind of resonance DC/DC converter
CN106505869A (en) * 2016-11-01 2017-03-15 东南大学 A kind of grid-connected combined type resonant full bridge changer of new forms of energy direct current and control method
CN107493015B (en) * 2017-09-14 2019-08-23 北京理工大学 A kind of two-way DC converter and its Poewr control method of dual transformer structure
CN114337344A (en) * 2022-01-10 2022-04-12 湖北工业大学 Control method based on self-adaptive hybrid rectification multi-switch resonant LLC converter

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN212992651U (en) * 2020-09-27 2021-04-16 中山市金兴智能技术有限公司 Asymmetric half-bridge circuit and lighting system

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