CN117614239A - Control method and control circuit of synchronous rectification circuit and full-bridge DCDC resonance device - Google Patents
Control method and control circuit of synchronous rectification circuit and full-bridge DCDC resonance device Download PDFInfo
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- CN117614239A CN117614239A CN202311476121.9A CN202311476121A CN117614239A CN 117614239 A CN117614239 A CN 117614239A CN 202311476121 A CN202311476121 A CN 202311476121A CN 117614239 A CN117614239 A CN 117614239A
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- HEZMWWAKWCSUCB-PHDIDXHHSA-N (3R,4R)-3,4-dihydroxycyclohexa-1,5-diene-1-carboxylic acid Chemical compound O[C@@H]1C=CC(C(O)=O)=C[C@H]1O HEZMWWAKWCSUCB-PHDIDXHHSA-N 0.000 title claims abstract description 72
- 238000000034 method Methods 0.000 title claims abstract description 23
- 230000002159 abnormal effect Effects 0.000 claims description 5
- 238000005259 measurement Methods 0.000 description 21
- 238000005070 sampling Methods 0.000 description 12
- 238000010586 diagram Methods 0.000 description 5
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- 239000010409 thin film Substances 0.000 description 2
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Classifications
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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
- H02M1/00—Details of apparatus for conversion
- H02M1/0003—Details of control, feedback or regulation circuits
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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
- H02M1/00—Details of apparatus for conversion
- H02M1/0048—Circuits or arrangements for reducing losses
-
- 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
- H02M3/01—Resonant DC/DC converters
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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
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- 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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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
The application relates to a control method of a synchronous rectification circuit, a control circuit and a full-bridge DCDC resonance device. The control circuit includes: the voltage acquisition module is used for acquiring the first port voltage of the output port of the full-bridge DCDC resonant converter and the first bridge arm midpoint voltage of the secondary synchronous rectification circuit; the enabling control module is connected with the voltage acquisition module and used for generating a first judgment signal according to the first port voltage and the first bridge arm midpoint voltage; the main control module is respectively connected with the voltage acquisition module and the enabling control module and is used for generating a second judgment signal according to the first port voltage and the first bridge arm midpoint voltage and generating a driving signal under the condition that the second judgment signal is the same as the first judgment signal; and the driving module is respectively connected with the main control module and the secondary synchronous rectification circuit and is used for driving the secondary synchronous rectification circuit to work according to the driving signal. The driving of the secondary synchronous rectification circuit is realized, and the reliability of the driving mode is higher.
Description
Technical Field
The application relates to the technical field of resonant converters, in particular to a control method and a control circuit of a synchronous rectification circuit and a full-bridge DCDC resonant device.
Background
In the field of full-bridge DCDC resonant converters at present, as the resonant current is always larger than the actual output current, in high-power topology, in order to reduce loss, the secondary full bridge needs to adopt a synchronous rectification mode.
The synchronous rectification control method in the related art mainly comprises the following steps: 1) A current measurement type; 2) Measuring voltage of the resonant device; 3) Switching tube voltage measurement. However, these control methods have the following problems: if a current measurement type or a voltage measurement type synchronous rectification scheme of a resonant device is adopted, the electric quantity to be measured is high-frequency alternating current quantity, and higher sampling precision is required to ensure the integrity of a resonant waveform, so that higher sampling rate is required. If the switching tube voltage measurement type synchronous rectification scheme is adopted, the switching tube body diode has low on voltage, the on voltages of the switching tube body diodes of different types are inconsistent, the judgment threshold value is closely related to the current switching tube model in actual use, and the actual anti-interference capability is poor due to the low on voltage.
Disclosure of Invention
In view of the foregoing, it is desirable to provide a new control method, control circuit and full-bridge DCDC resonant device for synchronous rectification circuits.
In a first aspect, the present application provides a control circuit for controlling a secondary synchronous rectification circuit of a full-bridge DCDC resonant converter, the control circuit comprising:
the voltage acquisition module is used for acquiring the first port voltage of the output port of the full-bridge DCDC resonant converter and the first bridge arm midpoint voltage of the secondary synchronous rectification circuit;
the enabling control module is connected with the voltage acquisition module and used for generating a first judging signal according to the first port voltage and the first bridge arm midpoint voltage;
the main control module is respectively connected with the voltage acquisition module and the enabling control module, and is used for generating a second judging signal according to the first port voltage and the first bridge arm midpoint voltage and generating a driving signal under the condition that the second judging signal is the same as the first judging signal;
and the driving module is respectively connected with the main control module and the secondary synchronous rectification circuit and is used for driving the secondary synchronous rectification circuit to work according to the driving signal.
In one embodiment, the first decision signal includes a first level signal and a second level signal; wherein,
the enabling control module is further configured to generate the first level signal when the first port voltage is the same as the first bridge arm midpoint voltage, generate the second level signal when the first port voltage is different from the first bridge arm midpoint voltage, and output a stop signal according to the second level signal;
the driving module is also connected with the enabling control module and is also used for controlling the secondary synchronous rectification circuit to stop working according to the received stop signal.
In one embodiment, the voltage acquisition module is further configured to acquire a midpoint voltage of a second bridge arm of a primary side synchronous rectification circuit of the full-bridge DCDC resonant converter;
the enabling control module is further configured to determine whether an operation condition of the full-bridge DCDC resonant converter is normal according to the second bridge arm midpoint voltage and the first bridge arm midpoint voltage, and generate the first determination signal according to the first port voltage and the first bridge arm midpoint voltage when a determination result is normal.
In one embodiment, the enabling control module is further configured to generate a stop signal when the determination result is abnormal, so that the driving module controls the secondary synchronous rectification circuit to stop working according to the stop signal.
In one embodiment, the voltage acquisition module includes:
the first acquisition circuit is respectively connected with the secondary synchronous rectification circuit and the output port of the full-bridge DCDC resonant converter and is used for acquiring the midpoint voltage of the first bridge arm and the first port voltage;
the driving module includes:
the first driving circuit is respectively connected with the main control module and the secondary synchronous rectification circuit and is used for driving the secondary synchronous rectification circuit to work according to the driving signal output by the main control module.
In one embodiment, the first driving circuit is further connected to the enabling control module, and the first driving circuit is further configured to control the secondary synchronous rectification circuit to stop working according to a stop signal output by the enabling control module.
In one embodiment, the voltage acquisition module further comprises:
the second acquisition circuit is connected with the primary side synchronous rectification circuit and is used for acquiring the midpoint voltage of a second bridge arm of the primary side synchronous rectification circuit of the full-bridge DCDC resonant converter;
the driving module includes:
and the second driving circuit is respectively connected with the enabling control module, the main control module and the primary side synchronous rectification circuit.
In one embodiment, the enabling control module includes:
the logic judging circuit is connected with the voltage acquisition module and is used for comparing whether the voltage of the first port is the same as the midpoint voltage of the first bridge arm;
the enabling control circuit is respectively connected with the logic judging circuit and the main control module and is used for generating the first level signal under the condition that the first port voltage and the first bridge arm midpoint voltage are the same, and generating the second level signal under the condition that the first port voltage and the first bridge arm midpoint voltage are different.
In a second aspect, the present application further provides a full-bridge DCDC resonant device, the full-bridge DCDC resonant device comprising:
a full bridge DCDC resonant converter; the method comprises the steps of,
the control circuit of the first aspect.
In a third aspect, the present application further provides a control method of a synchronous rectification circuit, for controlling a synchronous rectification circuit of a full-bridge DCDC resonant converter, where the control method of the synchronous rectification circuit includes:
acquiring a first port voltage and a first bridge arm midpoint voltage corresponding to a secondary side synchronous rectification circuit in a full-bridge DCDC resonant converter;
acquiring a first judgment signal for the first port voltage and the first bridge arm midpoint voltage based on an enabling control module;
acquiring a second judging signal for the first port voltage and the first bridge arm midpoint voltage based on a preset algorithm;
and generating a driving signal under the condition that the first judging signal and the second judging signal are the same so as to control a driving module to drive the secondary synchronous rectification circuit to work.
In one embodiment, the enabling control module obtains a first determination signal for the first port voltage and the first bridge arm midpoint voltage, including:
comparing the first port voltage with the first bridge arm midpoint voltage based on the enabling control module, generating a first level signal based on the enabling control module under the condition that the comparison results are the same, generating a second level signal based on the enabling control module under the condition that the comparison results are different, and outputting a stop signal based on the enabling control module according to the second level signal;
the generating a drive signal in the case where the first determination signal and the second determination signal are the same includes:
a drive signal is generated in the case where the first level signal and the second determination signal are the same.
In one embodiment, the control method of the synchronous rectification circuit further includes:
acquiring the midpoint voltage of a second bridge arm of the primary synchronous rectification circuit in the full-bridge DCDC resonant converter;
acquiring the operation working condition of the full-bridge DCDC resonant converter according to the midpoint voltage of the second bridge arm and the midpoint voltage of the first bridge arm based on the enabling control module;
and under the condition that the operation condition is normal, executing the step of acquiring a first judging signal for the first port voltage and the first bridge arm midpoint voltage based on the enabling control module.
The control method of the synchronous rectification circuit, the control circuit and the full-bridge DCDC resonance device are characterized in that the control circuit comprises a voltage acquisition module, an enabling control module, a main control module and a driving module. Collecting a first port voltage of an output port of the full-bridge DCDC resonant converter and a first bridge arm midpoint voltage of a secondary side synchronous rectification circuit of the full-bridge DCDC resonant converter through a voltage collecting module; then, generating a first judging signal according to the first port voltage and the first bridge arm midpoint voltage through the enabling control module, generating a second judging signal according to the first port voltage and the first bridge arm midpoint voltage through the main control module, and further generating a driving signal under the condition that the second judging signal is identical to the first judging signal through the main control module; and finally, driving a secondary side synchronous rectification circuit of the full-bridge DCDC resonant converter to work according to the driving signal by a driving module.
According to the technical scheme, the driving of the secondary synchronous rectification circuit of the full-bridge DCDC resonant converter is realized based on the first port voltage of the output port of the full-bridge DCDC resonant converter and the first bridge arm midpoint voltage of the secondary synchronous rectification circuit of the full-bridge DCDC resonant converter, and the driving is different from the control modes such as the current measurement mode, the resonant device voltage measurement mode, the switching tube voltage measurement mode and the like in the related technology, so that the problems in the related technology can be well avoided. That is, the technical solution of the embodiment of the present application is based on the first port voltage and the first bridge arm midpoint voltage, so that compared with the current measurement type or the resonant device voltage measurement type, the current sampling loss is lower, and meanwhile, the sampling rate requirement is lower, and compared with the switching tube voltage measurement type, the switching tube voltage measurement type switching tube can be compatible with different types of switching tubes, and has stronger anti-interference capability. In addition, because the technical scheme of the embodiment of the application is that the first port voltage and the first bridge arm midpoint voltage are judged by the two modules of the enabling control module and the main control module, the driving of the secondary synchronous rectification circuit is realized, and therefore the reliability of the driving mode is higher.
Drawings
FIG. 1 is a schematic diagram of a control circuit in one embodiment;
FIG. 2 is a schematic diagram of a full bridge DCDC resonant converter in one embodiment;
FIG. 3 is a schematic diagram of a control circuit in one embodiment;
FIG. 4 is a schematic diagram of a control circuit in one embodiment;
FIG. 5 is a schematic diagram of a control circuit in one embodiment;
fig. 6 is a flow chart of a control method of the synchronous rectification circuit in an embodiment.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.
The control circuit provided by the embodiment of the application can be applied to control of the secondary side synchronous rectification circuit of the full-bridge DCDC resonant converter. The full-bridge DCDC resonant converter may include a transformer including a primary coil and a secondary coil, and the power flow direction of the full-bridge DCDC resonant converter is generally from the primary coil side to the secondary coil side of the converter. The full-bridge DCDC resonant converter further comprises a full-bridge circuit located on the primary side of the transformer and a full-bridge circuit located on the secondary side of the transformer, respectively, and the two full-bridge circuits cooperate to realize DC-DC conversion of the converter, wherein the full-bridge circuit located on the secondary side of the transformer can be understood as a secondary side synchronous rectification circuit of the full-bridge DCDC resonant converter.
In one embodiment, as shown in fig. 1, a control circuit for controlling a secondary synchronous rectification circuit of a full-bridge DCDC resonant converter includes: the system comprises a voltage acquisition module 10, an enabling control module 20, a main control module 30 and a driving module 40.
The voltage acquisition module 10 is used for acquiring a first port voltage VBAT of an output port of the full-bridge DCDC resonant converter and a first bridge arm midpoint voltage V2 of the secondary synchronous rectification circuit. The voltage acquisition module 10 has a voltage acquisition function. The full bridge DCDC resonant converter may include an input port for an input voltage and an output port for an output voltage, the input port typically being located on the primary side of the transformer and the output port typically being located on the secondary side of the transformer.
Referring to fig. 2, an input port a and an output port B of the full-bridge DCDC resonant converter are exemplarily illustrated in fig. 2, and a full-bridge circuit C located at a primary side coil side of a transformer and a full-bridge circuit D located at a secondary side coil side of the transformer, both of which are composed of a plurality of field effect thin film transistors, are exemplarily illustrated. It will be appreciated that the output/input ports, the resonant cavity, the full-bridge circuit, and key components of the full-bridge circuit of the full-bridge DCDC resonant converter are only schematically illustrated in fig. 2, and the actual full-bridge DCDC resonant converter and the full-bridge circuit therein may further include other circuit components and circuit structures, which are not particularly limited in this embodiment. With continued reference to fig. 2, the voltage acquisition module 10 may respectively acquire the voltage at the output port of the full-bridge DCDC resonant converter, i.e., the first port voltage VBAT, and acquire the voltage at the midpoint of the full-bridge arm of the secondary synchronous rectification circuit, i.e., the first bridge arm midpoint voltage V2.
The enabling control module 20 is connected with the voltage acquisition module 10. The enabling control module 20 is a hardware circuit module formed by circuit components such as an amplifier, an integrated circuit, and the like, and based on this, the enabling control module 20 receives the first port voltage VBAT and the first bridge arm midpoint voltage V2 from the voltage acquisition module 10, and generates a first determination signal according to the first port voltage VBAT and the first bridge arm midpoint voltage V2.
The main control module 30 is respectively connected with the voltage acquisition module 10 and the enabling control module 20. The main control module 30 may include a main control chip, in which a preset algorithm may be written, based on which, the main control module 30 receives the first port voltage VBAT and the first bridge arm midpoint voltage V2 from the voltage collecting module 10, generates a second determination signal according to the first port voltage VBAT and the first bridge arm midpoint voltage V2, and the main control module 30 also receives the first determination signal from the enable control module 20, and generates a driving signal when it is determined that the second determination signal is the same as the first determination signal.
The driving module 40 is connected with the main control module 30 and the secondary synchronous rectification circuit respectively. The driving module 40 may be formed of a field effect thin film transistor. The driving module 40 can drive the secondary side rectifying circuit to work normally or control the secondary side rectifying circuit to stop working according to the received electric signal, and based on this, the driving module 40 receives the driving signal from the main control module 30 so as to drive the secondary side synchronous rectifying circuit of the full-bridge DCDC resonant converter to work.
According to the embodiment of the application, based on the first port voltage VBAT of the output port of the full-bridge DCDC resonant converter and the first bridge arm midpoint voltage V2 of the secondary side synchronous rectification circuit of the full-bridge DCDC resonant converter, the driving of the secondary side synchronous rectification circuit of the full-bridge DCDC resonant converter is realized, and the control modes such as a current measurement mode, a resonant device voltage measurement mode, a switching tube voltage measurement mode, a secondary side adopting a delay on-off scheme and the like in the related art are different, so that the problems existing in the related art can be well avoided. That is, according to the technical scheme of the embodiment of the application, due to the fact that the synchronous rectification driving is achieved based on the first port voltage VBAT of the converter and the first bridge arm midpoint voltage V2 of the full-bridge circuit, compared with the current measurement type or the resonant device voltage measurement type, the synchronous rectification driving device is lower in current sampling loss, meanwhile, the first bridge arm midpoint voltage V2 is ideally rectangular wave, so that the sampling rate requirement is lower, compared with the switching tube voltage measurement type, the synchronous rectification driving device can be compatible with different types and different types of switching tubes of the full-bridge circuit, and has stronger anti-interference capability. In addition, because the technical scheme of the embodiment of the application is that the enabling control module 20 configured by a hardware circuit and the main control module 30 configured by a software algorithm are used for judging the first port voltage VBAT and the first bridge arm midpoint voltage V2 in a double manner, so that the driving of the secondary synchronous rectification circuit is realized, and the reliability of the driving mode is higher.
In one embodiment, the first decision signal includes a first level signal and a second level signal. Illustratively, the first level signal may be a high level signal and the second level signal may be a low level signal.
The enable control module 20 generates a first level signal if the first port voltage VBAT and the first leg midpoint voltage V2 are the same. Even if the control module 20 receives the first port voltage VBAT and the first bridge arm midpoint voltage V2 from the voltage collecting module 10, and compares the first port voltage VBAT with the first bridge arm midpoint voltage V2, the control module 20 is enabled to determine whether the full-bridge DCDC resonant converter has a fault, where the fault is for example, a device short circuit, a power supply reverse connection, etc. in the converter. When the comparison result is the same, the enabling control module 20 considers that the converter has not failed, and the enabling control module 20 generates a first level signal according to the failure.
In synchronization, the main control module 30 receives the first port voltage VBAT and the first bridge arm midpoint voltage V2 from the voltage collecting module 10, and compares the first port voltage VBAT with the first bridge arm midpoint voltage V2, so that the main control module 30 determines whether the full-bridge DCDC resonant converter has a fault, for example, a short circuit of a device in the converter, reverse connection of a power supply, and the like. When the comparison result is the same, the main control module 30 considers that the converter has not failed, and the second determination signal generated by the main control module 30 according to the comparison result is also the first level signal. Furthermore, the main control module 30 receives the first level signal generated by the enabling control module 20 from the enabling control module 20, compares the first level signal with the second determination signal, and generates a driving signal according to the comparison result, and the driving module 40 drives the secondary synchronous rectification circuit to work according to the received driving signal.
Referring to fig. 1, when the first port voltage VBAT and the first bridge arm midpoint voltage V2 are different, the enabling control module 20 considers that the converter fails, the enabling control module 20 generates a second level signal according to the failure, and the enabling control module 20 outputs a stop signal according to the second level signal. The driving module 40 is further connected to the enable control module 20, and the driving module 40 is further configured to control the secondary synchronous rectification circuit to stop working according to the received stop signal, so as to protect the converter.
In synchronization, when the first port voltage VBAT and the first bridge arm midpoint voltage V2 are different, the master control module 30 considers that the converter fails, and the signal generated by the master control module 30 is an invalid signal, that is, the second determination signal may not be output, or the second determination signal may be an invalid signal.
In this embodiment of the present application, the control circuit works in real time, and when the enabling control module 20 configured by the hardware circuit and the main control module 30 configured by the software algorithm determine that the converter does not fail, the main control module 30 generates a driving signal, and the driving module 40 drives the secondary synchronous rectification circuit to work according to the received driving signal, so as to realize reliable driving of the secondary synchronous rectification circuit. When the enabling control module 20 configured by the hardware circuit judges that the converter fails, the enabling control module 20 directly outputs a stop signal to the driving module 40, and the driving module 40 controls the secondary synchronous rectification circuit to stop working according to the received stop signal, so that the protection of the converter is realized. Because the technical scheme of the embodiment of the application is that under the condition that the converter fails, the enabling control module 20 configured by a hardware circuit directly controls the driving module 40 to stop working of the secondary synchronous rectification circuit, compared with the case that the main control module 30 configured by a software algorithm controls the driving module 40 to stop working of the secondary synchronous rectification circuit, the pure hardware circuit is lower in delay of cutting off the failure protection converter, is quicker in response, and can cut off the failure rapidly to realize protection of the converter.
In one embodiment, with continued reference to fig. 2, the voltage acquisition module 10 is further configured to acquire a second leg midpoint voltage V1 of the primary synchronous rectification circuit of the full-bridge DCDC resonant converter. The enabling control module 20 is configured to determine whether the operation condition of the full-bridge DCDC resonant converter is normal according to the second bridge arm midpoint voltage V1 and the first bridge arm midpoint voltage V2, and generate a first determination signal according to the first port voltage VBAT and the first bridge arm midpoint voltage V2 if the determination result is normal.
Specifically, under the condition that a power flow direction is given, under the condition that the operation condition of the converter is stable and normal, the polarities of the midpoint voltage V2 of the first bridge arm and the midpoint voltage V1 of the second bridge arm are the same; if the polarities of the midpoint voltage V2 of the first bridge arm and the midpoint voltage V1 of the second bridge arm are different, the fault of the converter is indicated, and the operation condition of the converter is abnormal.
Accordingly, in the embodiment of the present application, before the secondary synchronous rectification circuit is driven by the control circuit, the voltage acquisition module 10 acquires the midpoint voltage V1 of the second bridge arm of the primary synchronous rectification circuit of the full-bridge DCDC resonant converter, and the enable control module 20 compares the polarities of the midpoint voltage V1 of the second bridge arm and the midpoint voltage V2 of the first bridge arm, where the comparison result is the same polarity, the enable control module 20 considers that the operation condition of the converter is normal. Then, the enable control module 20 generates a first determination signal according to the received first port voltage VBAT and the first bridge arm midpoint voltage V2.
In one embodiment, the enabling control module 20 is further configured to generate a stop signal when the determination result is abnormal, so that the driving module 40 controls the secondary synchronous rectification circuit to stop working according to the stop signal.
Based on the above embodiment, specifically, before the secondary synchronous rectification circuit is driven by the control circuit, the voltage acquisition module 10 acquires the midpoint voltage V1 of the second bridge arm of the primary synchronous rectification circuit of the full-bridge DCDC resonant converter, the enabling control module 20 compares the polarities of the midpoint voltage V1 of the second bridge arm and the midpoint voltage V2 of the first bridge arm, and under the condition that the comparison results are different in polarity, the enabling control module 20 considers that the operation condition of the converter is faulty, the enabling control module 20 generates a stop signal accordingly, and the driving module 40 controls the secondary synchronous rectification circuit to stop working according to the stop signal.
In one embodiment, as shown in fig. 3, the voltage acquisition module 10 includes a first acquisition circuit 110 and the drive module 40 includes a first drive circuit 410.
The first acquisition circuit 110 is respectively connected with the secondary synchronous rectification circuit and the output port of the full-bridge DCDC resonant converter, and is used for acquiring the first bridge arm midpoint voltage V2 and the first port voltage VBAT. The first acquisition circuit 110 may include a high-resistance differential sampling circuit or an isolated differential sampling circuit, for example.
The first driving circuit 410 is connected to the main control module 30 and the secondary synchronous rectification circuit, respectively, and is configured to drive the secondary synchronous rectification circuit to operate according to a driving signal output by the main control module 30.
In one embodiment, the first driving circuit 410 is further connected to the enable control module 20, and the first driving circuit 410 is further configured to control the secondary synchronous rectification circuit to stop working according to a stop signal output by the enable control module 20.
In one embodiment, as shown in fig. 4, the voltage acquisition module 10 further includes a second acquisition circuit 120, and the driving module 40 further includes a second driving circuit 420.
The second acquisition circuit 120 is connected to the primary synchronous rectification circuit, and is configured to acquire a midpoint voltage V1 of a second bridge arm of the primary synchronous rectification circuit of the full-bridge DCDC resonant converter. The second acquisition circuit 120 may include a high-resistance differential sampling circuit or an isolated differential sampling circuit, for example.
The second driving circuit 420 is respectively connected with the enabling control module 20, the main control module 30 and the primary synchronous rectification circuit.
According to the technical scheme, when the power flow direction of the converter is changed, the roles of the primary full-bridge circuit and the secondary full-bridge circuit of the converter are interchanged. For example, in the case where the power flow direction is in a first direction, the first full-bridge circuit of the converter serves as a primary full-bridge circuit, the second full-bridge circuit of the converter serves as a secondary full-bridge circuit, and in the case where the power flow direction is changed from the first direction to a second direction, the first full-bridge circuit of the converter serves as a secondary full-bridge circuit, the second full-bridge circuit of the converter serves as a primary full-bridge circuit, and the second direction is opposite to the first direction.
In this embodiment, the voltage acquisition module 10 includes a first acquisition circuit 110 and a second acquisition circuit 120, and the driving module 40 includes a first driving circuit 410 and a second driving circuit 420, so that the primary full-bridge circuit and the secondary full-bridge circuit respectively have independent acquisition circuits and driving circuits all the time, regardless of roles of the full-bridge circuit and the secondary full-bridge circuit, the primary full-bridge circuit and the secondary full-bridge circuit respectively realize acquisition of electric signals and driving of the secondary synchronous rectification circuit through the respective corresponding acquisition circuits and driving circuits. Accordingly, the control circuit provided by the embodiment of the application is suitable for the forward and backward power flow direction of the converter, namely is suitable for the bidirectional operation working condition of the converter, has a simple structure, is fewer in configured devices and lower in cost, and is different from the synchronous rectification of a single circuit in the related art when the single circuit is basically only suitable for unidirectional operation of the converter.
In one embodiment, as shown in FIG. 5, the enable control module 20 includes: logic determination circuit 210 and enable control circuit 220. The logic judging circuit 210 is connected to the voltage collecting module 10, and is configured to receive the first port voltage VBAT and the first bridge arm midpoint voltage V2 from the voltage collecting module 10, and compare whether the first port voltage VBAT is the same as the first bridge arm midpoint voltage V2; the enable control circuit 220 is connected to the logic determination circuit 210 and the main control module 30, and is configured to generate a first level signal when the first port voltage VBAT is the same as the first bridge arm midpoint voltage V2, and generate a second level signal when the first port voltage VBAT is different from the first bridge arm midpoint voltage V2.
For example, the logic determination circuit 210 may be configured by circuit components such as an amplifier, and the enable control circuit 220 may be configured by circuit components such as an integrated circuit, a chip, and the like. In the technical scheme of the embodiment of the application, the voltage acquisition module 10 synchronizes the acquired electric signals to the enabling control module 20 and the main control module 30; the enabling control module 20 forms a pure hardware judging circuit of the secondary synchronous rectifying circuit, has low delay and high response speed, can rapidly control the secondary synchronous rectifying circuit to stop working, and protects the converter; the main control module 30 forms a pure software algorithm judging circuit of the secondary side synchronous rectifying circuit, so that whether the secondary side synchronous rectifying circuit fails or not can be reliably judged, and reliable driving of the secondary side synchronous rectifying circuit is realized.
Based on the same inventive concept, the embodiment of the application also provides a full-bridge DCDC resonance device. The full-bridge DCDC resonance device comprises a full-bridge DCDC resonance converter and a control circuit provided by any embodiment; the technical schemes included in the full-bridge DCDC resonance device and the control circuit are the same, so that the same technical problems can be solved, the same technical effects are achieved, and repeated contents are not repeated here.
Based on the same inventive concept, the embodiment of the application also provides a control method of the synchronous rectification circuit, which is used for controlling the synchronous rectification circuit of the full-bridge DCDC resonant converter. The control method of the synchronous rectification circuit provided by the embodiment of the application can be executed by a main control module in the control circuit.
In one embodiment, as shown in fig. 6, the control method of the synchronous rectification circuit includes the following steps 602 to 608:
step 602, a first port voltage and a first bridge arm midpoint voltage corresponding to a secondary synchronous rectification circuit in a full-bridge DCDC resonant converter are obtained.
Step 604, the enable control module obtains a first determination signal for the first port voltage and the first leg midpoint voltage.
Step 606, obtaining a second determination signal for the first port voltage and the first bridge arm midpoint voltage based on a preset algorithm. The main control module can comprise a main control chip, and a preset algorithm can be written on the main control chip.
And 608, generating a driving signal to control the driving module to drive the secondary synchronous rectification circuit to work under the condition that the first judging signal and the second judging signal are the same.
According to the technical scheme, due to the fact that the synchronous rectification driving is achieved based on the first port voltage of the converter and the first bridge arm midpoint voltage of the full-bridge circuit, compared with a current measurement type or a resonant device voltage measurement type, the synchronous rectification driving device is lower in current sampling loss, meanwhile, the first bridge arm midpoint voltage is rectangular wave under ideal conditions, so that the sampling rate requirement is lower, compared with a switching tube voltage measurement type, the synchronous rectification driving device can be compatible with different types and different types of switching tubes of the full-bridge circuit, and has stronger anti-interference capacity. In addition, because the technical scheme of the embodiment of the application is that the first port voltage and the first bridge arm midpoint voltage are determined by the enabling control module configured by the hardware circuit and the main control module configured by the software algorithm, so that the driving of the secondary synchronous rectification circuit is realized, and the reliability of the driving mode is higher.
In one embodiment, step 604 includes: and comparing the first port voltage with the first bridge arm midpoint voltage based on the enabling control module, generating a first level signal based on the enabling control module under the condition that the comparison results are the same, generating a second level signal based on the enabling control module under the condition that the comparison results are different, and outputting a stop signal based on the enabling control module according to the second level signal. Accordingly, step 608 includes: the driving signal is generated in the case where the first level signal and the second determination signal are the same.
In one embodiment, the control method of the synchronous rectification circuit further includes step 603: acquiring the midpoint voltage of a second bridge arm of the primary synchronous rectification circuit in the full-bridge DCDC resonant converter; and acquiring the operation working condition of the full-bridge DCDC resonant converter according to the midpoint voltage of the second bridge arm and the midpoint voltage of the first bridge arm based on the enabling control module. In the case where the operation condition is normal, step 604 is performed. And under the condition that the operation condition is abnormal, generating a stop signal based on the enabling control module, and controlling the secondary synchronous rectification circuit to stop working by the driving module according to the stop signal.
It should be understood that, although the steps in the flowcharts related to the embodiments described above are sequentially shown as indicated by arrows, these steps are not necessarily sequentially performed in the order indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least some of the steps in the flowcharts described in the above embodiments may include a plurality of steps or a plurality of stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of the steps or stages is not necessarily performed sequentially, but may be performed alternately or alternately with at least some of the other steps or stages.
The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the present application. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application shall be subject to the appended claims.
Claims (12)
1. A control circuit for controlling a secondary synchronous rectification circuit of a full-bridge DCDC resonant converter, the control circuit comprising:
the voltage acquisition module is used for acquiring the first port voltage of the output port of the full-bridge DCDC resonant converter and the first bridge arm midpoint voltage of the secondary synchronous rectification circuit;
the enabling control module is connected with the voltage acquisition module and used for generating a first judging signal according to the first port voltage and the first bridge arm midpoint voltage;
the main control module is respectively connected with the voltage acquisition module and the enabling control module, and is used for generating a second judging signal according to the first port voltage and the first bridge arm midpoint voltage and generating a driving signal under the condition that the second judging signal is the same as the first judging signal;
and the driving module is respectively connected with the main control module and the secondary synchronous rectification circuit and is used for driving the secondary synchronous rectification circuit to work according to the driving signal.
2. The control circuit of the synchronous rectification circuit according to claim 1, wherein said first determination signal includes a first level signal and a second level signal; wherein,
the enabling control module is further configured to generate the first level signal when the first port voltage is the same as the first bridge arm midpoint voltage, generate the second level signal when the first port voltage is different from the first bridge arm midpoint voltage, and output a stop signal according to the second level signal;
the driving module is also connected with the enabling control module and is also used for controlling the secondary synchronous rectification circuit to stop working according to the received stop signal.
3. The control circuit of the synchronous rectification circuit of claim 1, wherein said voltage acquisition module is further configured to acquire a second bridge arm midpoint voltage of a primary side synchronous rectification circuit of said full bridge DCDC resonant converter;
the enabling control module is further configured to determine whether an operation condition of the full-bridge DCDC resonant converter is normal according to the second bridge arm midpoint voltage and the first bridge arm midpoint voltage, and generate the first determination signal according to the first port voltage and the first bridge arm midpoint voltage when a determination result is normal.
4. The control circuit of claim 3, wherein the enabling control module is further configured to generate a stop signal to enable the driving module to control the secondary synchronous rectification circuit to stop operating according to the stop signal when the determination result is abnormal.
5. The control circuit of the synchronous rectification circuit of claim 1, wherein said voltage acquisition module comprises:
the first acquisition circuit is respectively connected with the secondary synchronous rectification circuit and the output port of the full-bridge DCDC resonant converter and is used for acquiring the midpoint voltage of the first bridge arm and the first port voltage;
the driving module includes:
the first driving circuit is respectively connected with the main control module and the secondary synchronous rectification circuit and is used for driving the secondary synchronous rectification circuit to work according to the driving signal output by the main control module.
6. The control circuit of the synchronous rectification circuit of claim 5, wherein said first driving circuit is further connected to said enabling control module, and said first driving circuit is further configured to control said secondary synchronous rectification circuit to stop operating according to a stop signal output from said enabling control module.
7. The control circuit of the synchronous rectification circuit of claim 5, wherein said voltage acquisition module further comprises:
the second acquisition circuit is connected with the primary side synchronous rectification circuit and is used for acquiring the midpoint voltage of a second bridge arm of the primary side synchronous rectification circuit of the full-bridge DCDC resonant converter;
the driving module includes:
and the second driving circuit is respectively connected with the enabling control module, the main control module and the primary side synchronous rectification circuit.
8. The control circuit of the synchronous rectification circuit according to claim 2, wherein said enabling control module comprises:
the logic judging circuit is connected with the voltage acquisition module and is used for comparing whether the voltage of the first port is the same as the midpoint voltage of the first bridge arm;
the enabling control circuit is respectively connected with the logic judging circuit and the main control module and is used for generating the first level signal under the condition that the first port voltage and the first bridge arm midpoint voltage are the same, and generating the second level signal under the condition that the first port voltage and the first bridge arm midpoint voltage are different.
9. A full bridge DCDC resonant assembly, comprising:
a full bridge DCDC resonant converter; the method comprises the steps of,
a control circuit as claimed in any one of claims 1 to 8.
10. A control method of a synchronous rectification circuit, characterized by being used for controlling a synchronous rectification circuit of a full-bridge DCDC resonant converter, the control method of the synchronous rectification circuit comprising:
acquiring a first port voltage and a first bridge arm midpoint voltage corresponding to a secondary side synchronous rectification circuit in a full-bridge DCDC resonant converter;
acquiring a first judgment signal for the first port voltage and the first bridge arm midpoint voltage based on an enabling control module;
acquiring a second judging signal for the first port voltage and the first bridge arm midpoint voltage based on a preset algorithm;
and generating a driving signal under the condition that the first judging signal and the second judging signal are the same so as to control a driving module to drive the secondary synchronous rectification circuit to work.
11. The method of controlling the synchronous rectification circuit according to claim 10, wherein the enabling control module obtains a first determination signal for the first port voltage and the first arm midpoint voltage, comprising:
comparing the first port voltage with the first bridge arm midpoint voltage based on the enabling control module, generating a first level signal based on the enabling control module under the condition that the comparison results are the same, generating a second level signal based on the enabling control module under the condition that the comparison results are different, and outputting a stop signal based on the enabling control module according to the second level signal;
the generating a drive signal in the case where the first determination signal and the second determination signal are the same includes:
a drive signal is generated in the case where the first level signal and the second determination signal are the same.
12. The control method of the synchronous rectification circuit according to claim 10, characterized in that the control method of the synchronous rectification circuit further comprises:
acquiring the midpoint voltage of a second bridge arm of the primary synchronous rectification circuit in the full-bridge DCDC resonant converter;
acquiring the operation working condition of the full-bridge DCDC resonant converter according to the midpoint voltage of the second bridge arm and the midpoint voltage of the first bridge arm based on the enabling control module;
and under the condition that the operation condition is normal, executing the step of acquiring a first judging signal for the first port voltage and the first bridge arm midpoint voltage based on the enabling control module.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311476121.9A CN117614239A (en) | 2023-11-03 | 2023-11-03 | Control method and control circuit of synchronous rectification circuit and full-bridge DCDC resonance device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311476121.9A CN117614239A (en) | 2023-11-03 | 2023-11-03 | Control method and control circuit of synchronous rectification circuit and full-bridge DCDC resonance device |
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| CN202311476121.9A Pending CN117614239A (en) | 2023-11-03 | 2023-11-03 | Control method and control circuit of synchronous rectification circuit and full-bridge DCDC resonance device |
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| CN (1) | CN117614239A (en) |
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