CN108667299B - Method for improving reliability of LLC resonant converter and related device - Google Patents

Method for improving reliability of LLC resonant converter and related device Download PDF

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CN108667299B
CN108667299B CN201710207415.XA CN201710207415A CN108667299B CN 108667299 B CN108667299 B CN 108667299B CN 201710207415 A CN201710207415 A CN 201710207415A CN 108667299 B CN108667299 B CN 108667299B
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resonant converter
llc resonant
value
parameter information
working frequency
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CN108667299A (en
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刘韧
首福俊
李清纯
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Dimension Corp.
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Emerson Energy Systems AB
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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
    • H02M3/33569—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 several active switching elements
    • 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

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  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)

Abstract

A method and related device for improving reliability of an LLC resonant converter can obtain intrinsic parameter information of the LLC resonant converter and parameter information representing the current load condition of the LLC resonant converter, and determine the lowest working frequency value of the LLC resonant converter working in a ZVS (zero voltage switching) region according to the intrinsic parameter information, the parameter information representing the current load condition of the LLC resonant converter and prestored working characteristic information of the LLC resonant converter; if the minimum value of the value range of the working frequency of the currently set LLC resonant converter is determined to be smaller than the lowest working frequency value, adjusting the minimum value of the value range of the working frequency to enable the minimum value to be not lower than the lowest working frequency value; namely, the minimum value of the working frequency of the LLC resonant converter can be adjusted in real time according to the load condition, the LLC resonant converter is ensured to work in a ZVS mode all the time, and the reliability of the LLC resonant converter is effectively improved.

Description

Method for improving reliability of LLC resonant converter and related device
Technical Field
The invention relates to the technical field of power supplies, in particular to a method for improving the reliability of an LLC resonant converter and a related device.
Background
At present, the switching power supply is developing towards high power density and high efficiency, and the LLC resonant converter is being widely applied due to its excellent soft switching characteristics and boosting capability.
Fig. 1 shows an operation characteristic diagram of the LLC resonant converter, wherein the ordinate is an absolute value of the voltage conversion ratio, the abscissa is a ratio of an operating frequency fs of the LLC resonant converter to a resonant frequency fr of the LLC resonant converter, and Qs is a quality factor. According to the dc gain characteristic of the LLC resonant converter, its operation mode can be divided into three operation regions, region 1 and region 2 being ZVS region (mode), region 3 being ZCS region (mode). For a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), the switching loss in ZVS mode is smaller than that in ZCS mode.
The silicon-based MOSFET body diode can be used as a primary side switching device of the LLC resonant converter. When the body diode of the silicon-based MOSFET is turned off, a large reverse recovery current is generated, so that when an LLC resonant converter using the silicon-based MOSFET as a primary switching device works in a ZCS region, the reliability of the switching device is seriously influenced by the excessively high reverse recovery current and switching loss of the LLC resonant converter, and therefore the LLC resonant converter is usually designed to work in a ZVS region and avoid working in the ZCS region. However, if no extra countermeasure is added, the LLC resonant converter inevitably enters the ZCS region at the time of startup, load jump, and input jump, resulting in reduced reliability.
To solve the above problems, the methods commonly used in the industry at present include: MOSFETs made of silicon carbide, silicon MOSFETs having a fast recovery characteristic, MOSFETs having a higher current capacity, or heat sinks having a higher heat dissipation performance are used. However, the above measures all increase the hardware cost of the LLC resonant converter.
Disclosure of Invention
The embodiment of the invention provides a method and a related device for improving the reliability of an LLC resonant converter, which are used for solving the problem of low reliability caused by MOSFET failure caused by the fact that the LLC resonant converter using a silicon-based MOSFET body diode as a primary side switching device works in a ZCS region during startup, load jump and input jump.
The embodiment of the invention provides a method for improving the reliability of an LLC resonant converter, which comprises the following steps:
acquiring intrinsic parameter information of an LLC resonant converter and parameter information representing the current load condition of the LLC resonant converter; the intrinsic parameter information comprises an inductance value of a resonant inductor of the LLC resonant converter, a capacitance value of a resonant capacitor of the LLC resonant converter, an inductance value of a primary coil of a transformer of the LLC resonant converter and an original secondary side turn ratio of the transformer of the LLC resonant converter;
determining the lowest working frequency value of the LLC resonant converter working in a ZVS region according to the acquired intrinsic parameter information, the parameter information representing the current load condition of the LLC resonant converter and the prestored working characteristic information of the LLC resonant converter;
if the minimum value of the currently set value range of the working frequency of the LLC resonant converter is determined to be smaller than the lowest working frequency value, adjusting the minimum value of the value range of the working frequency to enable the minimum value to be not lower than the lowest working frequency value; the working frequency of the LLC resonant converter is the frequency of a driving signal for driving a switching tube of the LLC resonant converter.
Optionally, the parameter information characterizing the current load condition of the LLC resonant converter includes:
a voltage value of an output voltage and a current value of an output current of the LLC resonant converter; and/or the presence of a gas in the gas,
a voltage value of an input voltage and a current value of an input current of the LLC resonant converter.
Optionally, the LLC resonant converter comprises any one of a full-bridge LLC resonant converter, a symmetric half-bridge LLC resonant converter, or an asymmetric half-bridge LLC resonant converter.
Accordingly, embodiments of the present invention also provide a computer-readable storage medium storing computer-executable instructions for causing a computer to perform any one of the above methods for improving reliability of an LLC resonant converter.
Correspondingly, an embodiment of the present invention further provides a device for improving reliability of an LLC resonant converter, including:
the acquiring unit is used for acquiring inherent parameter information of the LLC resonant converter and parameter information representing the current load condition of the LLC resonant converter; the intrinsic parameter information comprises an inductance value of a resonant inductor of the LLC resonant converter, a capacitance value of a resonant capacitor of the LLC resonant converter, an inductance value of a primary coil of a transformer of the LLC resonant converter and an original secondary side turn ratio of the transformer of the LLC resonant converter;
the calculation unit is used for determining the lowest working frequency value of the LLC resonant converter working in the ZVS region according to the acquired intrinsic parameter information, the parameter information representing the current load condition of the LLC resonant converter and the prestored working characteristic information of the LLC resonant converter;
the execution unit is used for adjusting the minimum value of the value range of the working frequency of the currently set LLC resonant converter to be not lower than the lowest working frequency value if the minimum value of the value range of the working frequency of the currently set LLC resonant converter is determined to be smaller than the lowest working frequency value; the working frequency of the LLC resonant converter is the frequency of a driving signal for driving a switching tube of the LLC resonant converter.
Optionally, the parameter information characterizing the current load condition of the LLC resonant converter includes:
a voltage value of an output voltage and a current value of an output current of the LLC resonant converter; and/or the presence of a gas in the gas,
a voltage value of an input voltage and a current value of an input current of the LLC resonant converter.
Optionally, the LLC resonant converter comprises any one of a full-bridge LLC resonant converter, a symmetric half-bridge LLC resonant converter, or an asymmetric half-bridge LLC resonant converter.
Correspondingly, an embodiment of the present invention further provides an entity apparatus for improving reliability of an LLC resonant converter, including:
a memory for storing program instructions and intrinsic parameter information of the LLC resonant converter; the intrinsic parameter information comprises an inductance value of a resonant inductor of the LLC resonant converter, a capacitance value of a resonant capacitor of the LLC resonant converter, an inductance value of a primary coil of a transformer of the LLC resonant converter and an original secondary side turn ratio of the transformer of the LLC resonant converter;
the sampling circuit is used for acquiring parameter information representing the current load condition of the LLC resonant converter;
the processor is used for calling the program instructions stored in the memory and executing the following steps according to the obtained program instructions: acquiring intrinsic parameter information of the LLC resonant converter and parameter information representing the current load condition of the LLC resonant converter; determining the lowest working frequency value of the LLC resonant converter working in a ZVS region according to the acquired intrinsic parameter information, the parameter information representing the current load condition of the LLC resonant converter and the prestored working characteristic information of the LLC resonant converter; if the minimum value of the currently set value range of the working frequency of the LLC resonant converter is determined to be smaller than the lowest working frequency value, adjusting the minimum value of the value range of the working frequency to enable the minimum value to be not lower than the lowest working frequency value; the working frequency of the LLC resonant converter is the frequency of a driving signal for driving a switching tube of the LLC resonant converter.
Optionally, the sampling circuit is specifically configured to collect a voltage value of an output voltage and a current value of an output current of the LLC resonant converter; and/or acquiring a voltage value of an input voltage and a current value of an input current of the LLC resonant converter.
Optionally, the LLC resonant converter comprises any one of a full-bridge LLC resonant converter, a symmetric half-bridge LLC resonant converter, or an asymmetric half-bridge LLC resonant converter.
The invention has the following beneficial effects:
the embodiment of the invention provides a method and a related device for improving the reliability of an LLC resonant converter, which can obtain the inherent parameter information of the LLC resonant converter and the parameter information representing the current load condition of the LLC resonant converter; the intrinsic parameter information comprises an inductance value of a resonant inductor of the LLC resonant converter, a capacitance value of a resonant capacitor of the LLC resonant converter, an inductance value of a primary coil of a transformer of the LLC resonant converter and an original secondary side turn ratio of the transformer of the LLC resonant converter; determining the lowest working frequency value of the LLC resonant converter working in a ZVS region according to the acquired intrinsic parameter information, the parameter information representing the current load condition of the LLC resonant converter and the prestored working characteristic information of the LLC resonant converter; if the minimum value of the currently set value range of the working frequency of the LLC resonant converter is determined to be smaller than the lowest working frequency value, adjusting the minimum value of the value range of the working frequency to be not lower than the lowest working frequency value; the working frequency of the LLC resonant converter is the frequency of a driving signal for driving a switching tube of the LLC resonant converter. That is to say, the minimum value of the working frequency of the LLC resonant converter can be adjusted in real time according to the load condition of the LLC resonant converter, so as to ensure that the LLC resonant converter always works in the ZVS mode; therefore, the reliability of the LLC resonant converter using the silicon-based MOSFET body diode as the primary side switching device during starting, load jump and input jump can be effectively improved; moreover, hardware improvement on the LLC resonant converter is not needed, and the improvement cost is low.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without inventive efforts.
FIG. 1 is a schematic diagram of the operating characteristics of an LLC resonant converter;
fig. 2 is a flowchart illustrating steps of a method for improving reliability of an LLC resonant converter in accordance with a first embodiment of the present invention;
fig. 3 is a topology structure diagram of a full-bridge LLC resonant converter in the first embodiment of the present invention;
fig. 4 is a topology diagram of a symmetric half-bridge LLC resonant converter in a first embodiment of the present invention;
fig. 5 is a topology diagram of an asymmetric half-bridge LLC resonant converter in a first embodiment of the present invention;
fig. 6 is a schematic structural diagram of an apparatus for improving reliability of an LLC resonant converter in a second embodiment of the present invention;
fig. 7 is a schematic structural diagram of a physical apparatus for improving reliability of an LLC resonant converter in a second embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The first embodiment is as follows:
a first embodiment of the present invention provides a method for improving reliability of an LLC resonant converter, and specifically, as shown in fig. 2, it is a flowchart of steps of the method in the first embodiment of the present invention, and the method may include the following steps:
step 201: acquiring intrinsic parameter information of an LLC resonant converter and parameter information representing the current load condition of the LLC resonant converter; the intrinsic parameter information includes an inductance value of a resonant inductor of the LLC resonant converter, a capacitance value of a resonant capacitor of the LLC resonant converter, an inductance value of a primary coil of a transformer of the LLC resonant converter, and an original-secondary turn ratio of the transformer of the LLC resonant converter.
Optionally, the LLC resonant converter may comprise any one of a full-bridge LLC resonant converter, a symmetric half-bridge LLC resonant converter, or an asymmetric half-bridge LLC resonant converter.
The topology of the full-bridge LLC resonant converter is shown in fig. 3, and includes: a full bridge circuit coupled to an input voltage and including four switching devices A, B, C, D; an inductor Lr connected in series with a capacitor Cr, coupled to the bridge circuit, and driven by the switching devices; a transformer T1 coupled to the resonant network; a rectifying circuit coupled to the transformer T1; an LC filter is coupled to the rectifying circuit and the transformer T1.
The topology of a symmetric half-bridge LLC resonant converter is shown in fig. 4, and includes: a half-bridge circuit coupled to an input voltage and including two switching devices A, B; the two capacitors Cr1 and Cr2 are connected in series and coupled to an input voltage; an inductor Lr coupled to the bridge circuit and driven by the switching devices; a transformer T1 coupled to the resonant network; a rectifying circuit coupled to the transformer T1; an LC filter is coupled to the rectifying circuit and the transformer T1.
The topology of the asymmetric half-bridge LLC resonant converter is shown in fig. 5, and includes: a half-bridge circuit coupled to an input voltage and including two switching devices A, B; an inductor Lr connected in series with a capacitor Cr, coupled to the bridge circuit, and driven by the switching devices; a transformer T1 coupled to the resonant network; a rectifying circuit coupled to the transformer T1; an LC filter is coupled to the rectifying circuit and the transformer T1.
The method provided by the embodiment of the present invention is applicable to the LLC resonant converters with the above three topologies, for example, taking an asymmetric half-bridge LLC resonant converter as an example, the acquired intrinsic parameter information of the asymmetric half-bridge LLC resonant converter may include: the inductance of the resonant inductor Lr, the capacitance of the resonant capacitor Cr, the inductance of the primary winding of the transformer T1, and the primary-secondary turn ratio of the transformer T1.
In addition, the inherent parameter information of any LLC resonant converter is fixed and does not change according to the change in load; therefore, for any LLC resonant converter, its intrinsic parameter information can be pre-stored in FLASH Memory or EEPROM (Electrically Erasable Programmable Read-Only Memory) for being obtained at any time when the method is executed.
Optionally, the parameter information characterizing the current load condition of the LLC resonant converter may include:
a voltage value of an output voltage and a current value of an output current of the LLC resonant converter; and/or the presence of a gas in the gas,
a voltage value of an input voltage and a current value of an input current of the LLC resonant converter.
Since the voltage value of the output voltage may be equal to the ratio of the voltage value of the input voltage to the original secondary winding ratio of the transformer of the LLC resonant converter, the current value of the output current is equal to the product of the current value of the input current and the original secondary winding ratio of the transformer of the LLC resonant converter; therefore, one or both of the output voltage and the input voltage, and one or both of the output current and the input current can be collected as parameter information representing the current load condition of the LLC resonant converter, which is not limited in this embodiment.
Optionally, the parameter information representing the current load condition of the LLC resonant converter may be collected by using a sampling circuit, for example, a voltage value of the output voltage of the LLC resonant converter may be collected by using a voltage sampling circuit, and a current value of the output current of the LLC resonant converter may be collected by using a current sampling circuit, which is not described herein again.
Step 202: and determining the lowest working frequency value of the LLC resonant converter working in the ZVS region according to the acquired intrinsic parameter information, the parameter information representing the current load condition of the LLC resonant converter and the prestored working characteristic information of the LLC resonant converter.
For example, taking an asymmetric half-bridge LLC resonant converter as an example, the conversion equation of the asymmetric half-bridge LLC resonant converter is, according to its operating characteristics:
Figure BDA0001260182380000081
wherein | M | is an absolute value of the voltage conversion rate;
Figure BDA0001260182380000082
Figure BDA0001260182380000083
wherein fs is a working frequency of the LLC resonant converter, Lr is an inductance value of a resonant inductor of the LLC resonant converter, Cr is a capacitance value of a resonant capacitor of the LLC resonant converter, Lp is an inductance value of a primary coil of a transformer of the LLC resonant converter, a is an original-secondary turn ratio of the transformer of the LLC resonant converter, VoIs the voltage value of the output voltage, IoIs the current value of the output current.
As can be seen from fig. 1 (schematic operating characteristic diagram of the LLC resonant converter), for any gain curve, the inflection point thereof is the critical point of the LLC resonant converter operating in the ZCS region and the ZVS region, and when the value of x (the ratio of the operating frequency fs of the LLC resonant converter to the resonant frequency fr of the LLC resonant converter) is smaller than the abscissa at the inflection point, the LLC harmonic is obtainedThe vibration converter will work in the ZCS region; therefore, only the conversion equation of the asymmetric half-bridge LLC resonant converter needs to be derived, and then the obtained Lr, Cr, Lp, a and V are obtainedoAnd IoAnd introducing a derivative equation, and determining the value of fs enabling the derivative to be 0, namely determining the lowest working frequency value enabling the asymmetric half-bridge LLC resonant converter to work in a ZVS region.
It should be noted that, since the load equivalent resistance R can also be obtained by calculating a voltage value of an input voltage, a current value of an input current, and an original secondary side turn ratio of a transformer of the LLC resonant converter, when the voltage value of the input voltage and the current value of the input current of the LLC resonant converter are collected as parameter information representing a current load condition of the LLC resonant converter, a method for determining a lowest working frequency value of the LLC resonant converter working in a ZVS region is similar, and details are not repeated herein.
It should still be noted that, because the operating characteristics of the LLC resonant converters of different topologies are similar, only the expressions of the conversion equations are not completely the same, therefore, for LLC resonant converters of other topologies, the determination method of the lowest operating frequency value of the LLC resonant converter operating in the ZVS region is also similar, and this embodiment is not described herein again.
Step 203: if the minimum value of the currently set value range of the working frequency of the LLC resonant converter is determined to be smaller than the lowest working frequency value, adjusting the minimum value of the value range of the working frequency to enable the minimum value to be not lower than the lowest working frequency value; the working frequency of the LLC resonant converter is the frequency of a driving signal for driving a switching tube of the LLC resonant converter.
Optionally, an initial working frequency range may be set for the LLC resonant converter in advance according to an actual use condition, and then a minimum value of the working frequency range is adjusted in real time according to a load condition or before a drive circuit of the LLC resonant converter sends a wave each time.
Preferably, if it is determined that the minimum value of the currently set value range of the operating frequency of the LLC resonant converter is smaller than the lowest operating frequency value, the minimum value of the value range of the operating frequency may be adjusted to be equal to the lowest operating frequency value.
Optionally, if it is determined that the minimum value of the currently set value range of the operating frequency of the LLC resonant converter is not less than the minimum operating frequency value, the minimum value of the value range of the operating frequency may be kept unchanged.
Accordingly, an embodiment of the present invention further provides a computer-readable storage medium, which stores computer-executable instructions for causing a computer to perform any one of the above-mentioned methods for improving reliability of an LLC resonant converter.
In summary, the method for improving the reliability of the LLC resonant converter provided in the embodiments of the present invention can obtain the intrinsic parameter information of the LLC resonant converter and the parameter information representing the current load condition of the LLC resonant converter; the intrinsic parameter information comprises an inductance value of a resonant inductor of the LLC resonant converter, a capacitance value of a resonant capacitor of the LLC resonant converter, an inductance value of a primary coil of a transformer of the LLC resonant converter and an original secondary side turn ratio of the transformer of the LLC resonant converter; determining the lowest working frequency value of the LLC resonant converter working in a ZVS region according to the acquired intrinsic parameter information, the parameter information representing the current load condition of the LLC resonant converter and the prestored working characteristic information of the LLC resonant converter; if the minimum value of the currently set value range of the working frequency of the LLC resonant converter is determined to be smaller than the lowest working frequency value, adjusting the minimum value of the value range of the working frequency to be not lower than the lowest working frequency value; the working frequency of the LLC resonant converter is the frequency of a driving signal for driving a switching tube of the LLC resonant converter. That is to say, the minimum value of the working frequency of the LLC resonant converter can be adjusted in real time according to the load condition of the LLC resonant converter, so as to ensure that the LLC resonant converter always works in the ZVS mode; therefore, the reliability of the LLC resonant converter using the silicon-based MOSFET body diode as the primary side switching device during starting, load jump and input jump can be effectively improved; moreover, hardware improvement on the LLC resonant converter is not needed, and the improvement cost is low.
Example two:
based on the same inventive concept, a second embodiment of the present invention provides an apparatus for improving reliability of an LLC resonant converter, and specifically, as shown in fig. 6, it is a schematic structural diagram of the apparatus in the second embodiment of the present invention, and the apparatus may include:
an obtaining unit 601, configured to obtain intrinsic parameter information of an LLC resonant converter and parameter information representing a current load condition of the LLC resonant converter; the intrinsic parameter information comprises an inductance value of a resonant inductor of the LLC resonant converter, a capacitance value of a resonant capacitor of the LLC resonant converter, an inductance value of a primary coil of a transformer of the LLC resonant converter and an original secondary side turn ratio of the transformer of the LLC resonant converter;
a calculating unit 602, configured to determine, according to the acquired intrinsic parameter information, the parameter information representing the current load condition of the LLC resonant converter, and prestored working characteristic information of the LLC resonant converter, a lowest working frequency value at which the LLC resonant converter works in a ZVS region;
an executing unit 603, configured to adjust a minimum value of a value range of the working frequency of the currently set LLC resonant converter to be not lower than the lowest working frequency value if it is determined that the minimum value of the value range of the working frequency is smaller than the lowest working frequency value; the working frequency of the LLC resonant converter is the frequency of a driving signal for driving a switching tube of the LLC resonant converter.
Optionally, the parameter information characterizing the current load condition of the LLC resonant converter may include:
a voltage value of an output voltage and a current value of an output current of the LLC resonant converter; and/or the presence of a gas in the gas,
a voltage value of an input voltage and a current value of an input current of the LLC resonant converter.
Optionally, the LLC resonant converter may comprise any one of a full-bridge LLC resonant converter, a symmetric half-bridge LLC resonant converter, or an asymmetric half-bridge LLC resonant converter.
An entity apparatus for improving reliability of an LLC resonant converter is further provided in the second embodiment of the present invention, specifically, as shown in fig. 7, which is a schematic structural diagram of the entity apparatus in the second embodiment of the present invention, the entity apparatus may include:
a memory 701 for storing program instructions and intrinsic parameter information of the LLC resonant converter; the intrinsic parameter information comprises an inductance value of a resonant inductor of the LLC resonant converter, a capacitance value of a resonant capacitor of the LLC resonant converter, an inductance value of a primary coil of a transformer of the LLC resonant converter and an original secondary side turn ratio of the transformer of the LLC resonant converter;
the sampling circuit 702 is configured to acquire parameter information representing a current load condition of the LLC resonant converter;
the processor 703 is configured to call the program instructions stored in the memory 701, and execute, according to the obtained program instructions: acquiring intrinsic parameter information of the LLC resonant converter and parameter information representing the current load condition of the LLC resonant converter; determining the lowest working frequency value of the LLC resonant converter working in a ZVS region according to the acquired intrinsic parameter information, the parameter information representing the current load condition of the LLC resonant converter and the prestored working characteristic information of the LLC resonant converter; if the minimum value of the currently set value range of the working frequency of the LLC resonant converter is determined to be smaller than the lowest working frequency value, adjusting the minimum value of the value range of the working frequency to enable the minimum value to be not lower than the lowest working frequency value; the working frequency of the LLC resonant converter is the frequency of a driving signal for driving a switching tube of the LLC resonant converter.
It should be noted that, for any LLC resonant converter, the intrinsic parameter information is fixed and invariant, and does not change according to the change of the load; therefore, for any LLC resonant converter, its intrinsic parameter information can be pre-stored in the memory 701 for the processor 703 to obtain at any time when executing the program instructions.
Optionally, the sampling circuit 702 may be specifically configured to acquire a voltage value of an output voltage and a current value of an output current of the LLC resonant converter; and/or acquiring a voltage value of an input voltage and a current value of an input current of the LLC resonant converter.
Optionally, the sampling circuit 702 may specifically be a voltage sampling circuit and a current sampling circuit, for example, the voltage sampling circuit may be used to acquire a voltage value of an output voltage of the LLC resonant converter, and the current sampling circuit may be used to acquire a current value of an output current of the LLC resonant converter, which is not described herein again.
Optionally, the LLC resonant converter may comprise any one of a full-bridge LLC resonant converter, a symmetric half-bridge LLC resonant converter, or an asymmetric half-bridge LLC resonant converter.
In summary, the related apparatus for improving the reliability of the LLC resonant converter provided in the embodiments of the present invention can obtain the intrinsic parameter information of the LLC resonant converter and the parameter information representing the current load condition of the LLC resonant converter; the intrinsic parameter information comprises an inductance value of a resonant inductor of the LLC resonant converter, a capacitance value of a resonant capacitor of the LLC resonant converter, an inductance value of a primary coil of a transformer of the LLC resonant converter and an original secondary side turn ratio of the transformer of the LLC resonant converter; determining the lowest working frequency value of the LLC resonant converter working in a ZVS region according to the acquired intrinsic parameter information, the parameter information representing the current load condition of the LLC resonant converter and the prestored working characteristic information of the LLC resonant converter; if the minimum value of the currently set value range of the working frequency of the LLC resonant converter is determined to be smaller than the lowest working frequency value, adjusting the minimum value of the value range of the working frequency to be not lower than the lowest working frequency value; the working frequency of the LLC resonant converter is the frequency of a driving signal for driving a switching tube of the LLC resonant converter. That is to say, the minimum value of the working frequency of the LLC resonant converter can be adjusted in real time according to the load condition of the LLC resonant converter, so as to ensure that the LLC resonant converter always works in the ZVS mode; therefore, the reliability of the LLC resonant converter using the silicon-based MOSFET body diode as the primary side switching device during starting, load jump and input jump can be effectively improved; moreover, hardware improvement on the LLC resonant converter is not needed, and the improvement cost is low.
It is to be understood that any number of elements in the figures and descriptions are presented by way of example and not limitation, and that any nomenclature is used for distinction and not limitation.
As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, apparatus (device), or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present invention has been described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (devices) and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims (10)

1. A method of improving reliability of an LLC resonant converter, the method comprising:
acquiring intrinsic parameter information of an LLC resonant converter and parameter information representing the current load condition of the LLC resonant converter; the intrinsic parameter information comprises an inductance value of a resonant inductor of the LLC resonant converter, a capacitance value of a resonant capacitor of the LLC resonant converter, an inductance value of a primary coil of a transformer of the LLC resonant converter and an original secondary side turn ratio of the transformer of the LLC resonant converter;
determining the lowest working frequency value of the LLC resonant converter working in a ZVS region according to the acquired intrinsic parameter information, the parameter information representing the current load condition of the LLC resonant converter and the prestored working characteristic information of the LLC resonant converter;
if the minimum value of the currently set value range of the working frequency of the LLC resonant converter is determined to be smaller than the lowest working frequency value, adjusting the minimum value of the value range of the working frequency to enable the minimum value to be not lower than the lowest working frequency value; the working frequency of the LLC resonant converter is the frequency of a driving signal for driving a switching tube of the LLC resonant converter.
2. The method for improving reliability of the LLC resonant converter as claimed in claim 1, wherein said parameter information characterizing a current load condition of the LLC resonant converter comprises:
a voltage value of an output voltage and a current value of an output current of the LLC resonant converter; and/or the presence of a gas in the gas,
a voltage value of an input voltage and a current value of an input current of the LLC resonant converter.
3. The method of improving reliability of an LLC resonant converter as claimed in claim 1, wherein said LLC resonant converter comprises any one of a full bridge LLC resonant converter, a symmetric half bridge LLC resonant converter or an asymmetric half bridge LLC resonant converter.
4. A computer-readable storage medium storing computer-executable instructions for causing a computer to perform the method for improving reliability of an LLC resonant converter as claimed in any one of claims 1 to 3.
5. An apparatus for improving reliability of an LLC resonant converter, the apparatus comprising:
the acquiring unit is used for acquiring inherent parameter information of the LLC resonant converter and parameter information representing the current load condition of the LLC resonant converter; the intrinsic parameter information comprises an inductance value of a resonant inductor of the LLC resonant converter, a capacitance value of a resonant capacitor of the LLC resonant converter, an inductance value of a primary coil of a transformer of the LLC resonant converter and an original secondary side turn ratio of the transformer of the LLC resonant converter;
the calculation unit is used for determining the lowest working frequency value of the LLC resonant converter working in the ZVS region according to the acquired intrinsic parameter information, the parameter information representing the current load condition of the LLC resonant converter and the prestored working characteristic information of the LLC resonant converter;
the execution unit is used for adjusting the minimum value of the value range of the working frequency of the currently set LLC resonant converter to be not lower than the lowest working frequency value if the minimum value of the value range of the working frequency of the currently set LLC resonant converter is determined to be smaller than the lowest working frequency value; the working frequency of the LLC resonant converter is the frequency of a driving signal for driving a switching tube of the LLC resonant converter.
6. An apparatus for improving reliability of an LLC resonant converter as claimed in claim 5, wherein said parameter information characterizing a current load condition of said LLC resonant converter comprises:
a voltage value of an output voltage and a current value of an output current of the LLC resonant converter; and/or the presence of a gas in the gas,
a voltage value of an input voltage and a current value of an input current of the LLC resonant converter.
7. An apparatus for improving reliability of an LLC resonant converter as claimed in claim 5, wherein said LLC resonant converter comprises any one of a full bridge LLC resonant converter, a symmetric half bridge LLC resonant converter or an asymmetric half bridge LLC resonant converter.
8. An apparatus for improving reliability of an LLC resonant converter, the apparatus comprising:
a memory for storing program instructions and intrinsic parameter information of the LLC resonant converter; the intrinsic parameter information comprises an inductance value of a resonant inductor of the LLC resonant converter, a capacitance value of a resonant capacitor of the LLC resonant converter, an inductance value of a primary coil of a transformer of the LLC resonant converter and an original secondary side turn ratio of the transformer of the LLC resonant converter;
the sampling circuit is used for acquiring parameter information representing the current load condition of the LLC resonant converter;
the processor is used for calling the program instructions stored in the memory and executing the following steps according to the obtained program instructions: acquiring intrinsic parameter information of the LLC resonant converter and parameter information representing the current load condition of the LLC resonant converter; determining the lowest working frequency value of the LLC resonant converter working in a ZVS region according to the acquired intrinsic parameter information, the parameter information representing the current load condition of the LLC resonant converter and the prestored working characteristic information of the LLC resonant converter; if the minimum value of the currently set value range of the working frequency of the LLC resonant converter is determined to be smaller than the lowest working frequency value, adjusting the minimum value of the value range of the working frequency to enable the minimum value to be not lower than the lowest working frequency value; the working frequency of the LLC resonant converter is the frequency of a driving signal for driving a switching tube of the LLC resonant converter.
9. The apparatus according to claim 8, wherein the sampling circuit is specifically configured to collect a voltage value of an output voltage and a current value of an output current of the LLC resonant converter; and/or acquiring a voltage value of an input voltage and a current value of an input current of the LLC resonant converter.
10. The apparatus of claim 8, wherein the LLC resonant converter comprises any one of a full bridge LLC resonant converter, a symmetric half bridge LLC resonant converter, or an asymmetric half bridge LLC resonant converter.
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CN110212767B (en) * 2019-04-30 2020-08-04 东南大学 Digital control method for realizing multi-step frequency modulation of LL C resonant converter
CN111509981B (en) * 2019-12-30 2021-11-05 中国船舶重工集团公司第七0九研究所 Frequency self-adaptive control method and system of LLC resonant converter
CN112688574B (en) 2021-03-18 2021-07-20 深圳市正浩创新科技股份有限公司 Resonant converter and limit frequency variable control method thereof
CN114421781B (en) * 2022-03-31 2022-07-15 深圳市芯茂微电子有限公司 Control method of resonant converter
CN117639518B (en) * 2024-01-26 2024-04-23 西安图为电气技术有限公司 Bidirectional LLC resonant converter control method and device

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