WO2022077751A1 - 开关电源与电子设备 - Google Patents

开关电源与电子设备 Download PDF

Info

Publication number
WO2022077751A1
WO2022077751A1 PCT/CN2020/135487 CN2020135487W WO2022077751A1 WO 2022077751 A1 WO2022077751 A1 WO 2022077751A1 CN 2020135487 W CN2020135487 W CN 2020135487W WO 2022077751 A1 WO2022077751 A1 WO 2022077751A1
Authority
WO
WIPO (PCT)
Prior art keywords
clamping
capacitor
switch
clamp
clamping capacitor
Prior art date
Application number
PCT/CN2020/135487
Other languages
English (en)
French (fr)
Inventor
郭春明
邱治维
张程龙
Original Assignee
华源智信半导体(深圳)有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 华源智信半导体(深圳)有限公司 filed Critical 华源智信半导体(深圳)有限公司
Priority to US17/434,295 priority Critical patent/US11837950B2/en
Publication of WO2022077751A1 publication Critical patent/WO2022077751A1/zh

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • 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
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • H02M1/34—Snubber circuits
    • 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
    • H02M1/0006—Arrangements for supplying an adequate voltage to the control circuit of converters
    • 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
    • H02M1/0032—Control circuits allowing low power mode operation, e.g. in standby mode
    • 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
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • 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
    • H02M3/33507—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 with automatic control of the output voltage or current, e.g. flyback converters
    • 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
    • H02M3/33561—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 more than one ouput with independent control
    • 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
    • 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
    • H02M3/33576—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 having at least one active switching element at the secondary side of an isolation transformer
    • 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
    • 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
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • H02M1/322—Means for rapidly discharging a capacitor of the converter for protecting electrical components or for preventing electrical shock
    • 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
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • H02M1/34—Snubber circuits
    • H02M1/342—Active non-dissipative snubbers
    • 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

Definitions

  • the invention relates to a switching power supply, in particular to a switching power supply and electronic equipment.
  • Switching power supply widely used in alternating current-direct current (AC/DC) and direct current-direct current (DC/DC) conversion, and provides insulating isolation between the input side and the output side.
  • AC/DC alternating current-direct current
  • DC/DC direct current-direct current
  • Switching power supply widely used in alternating current-direct current (AC/DC) and direct current-direct current (DC/DC) conversion, and provides insulating isolation between the input side and the output side.
  • AC/DC alternating current-direct current
  • DC/DC direct current-direct current
  • the switching power supply may be provided with a transformer and an active clamp circuit, and the active clamp circuit may store the leakage inductance energy of the transformer through a clamp capacitor and send it back to the transformer.
  • the present invention provides a switching power supply and electronic equipment to solve the problem that the clamp switch and the output diode may be damaged.
  • a switching power supply comprising: an active clamp circuit and a transformer, wherein the active clamp circuit includes a first clamp capacitor and a second clamp capacitor, characterized in that the The active clamping circuit further includes: a path guiding module; the path guiding module is respectively connected to both ends of the first clamping capacitor and both ends of the second clamping capacitor; the path guiding module, the The first clamping capacitor and the second clamping capacitor are both connected to the primary side of the transformer;
  • the path guidance module is used to:
  • the first clamping capacitor is directed to discharge the primary side of the transformer after being connected in parallel with the second clamping capacitor.
  • the active clamp circuit further includes a clamp switch, and the primary side of the transformer includes a first leakage inductance, a first primary winding, a second leakage inductance and a second primary winding connected in sequence;
  • the first end of the first clamping capacitor is connected to the end of the first leakage inductance away from the first primary winding
  • the second end of the second clamping capacitor is connected to the first end of the clamping switch
  • the The second end of the clamping switch is connected to the end of the second primary winding that is far away from the second leakage inductance
  • the path guiding module is connected to the end of the second leakage inductance that is far away from the second primary winding
  • the path guidance module is specifically used for:
  • the first clamping capacitor is guided to obtain power from the first leakage inductance and the first primary winding
  • the second clamping capacitor is guided from the second leakage inductance and the first primary winding.
  • the second primary winding obtains electrical energy
  • the first leakage inductance, the first primary winding, the second leakage inductance and the second leakage inductance are connected in parallel with the first clamping capacitor and the second clamping capacitor in parallel. Primary winding discharges.
  • the path guiding module includes a first diode and a second diode
  • the first end of the first clamping capacitor is connected to the end of the first leakage inductance away from the first primary winding
  • the cathode of the first diode is connected to the second end of the first clamping capacitor
  • the The anode of the first diode is connected to the cathode of the second diode
  • the cathode of the second diode is also connected to the end of the second leakage inductance away from the second primary winding
  • the second and second The positive pole of the pole tube is connected to the first end of the second clamp capacitor
  • the second end of the second clamp capacitor is connected to the first end of the clamp switch
  • the second end of the clamp switch is connected to the end of the second primary winding away from the second leakage inductance.
  • the path guiding module further includes a third diode and a fourth diode;
  • the anode of the third diode is connected to the first end of the first clamping capacitor, the cathode of the third diode is connected to the first end of the second clamping capacitor, and the fourth diode is connected to the first end of the second clamping capacitor.
  • the anode of the tube is connected to the second end of the first clamping capacitor, and the cathode of the fourth diode is connected to the second end of the second clamping capacitor.
  • the switching power supply further includes a main switch and a controller, the first end of the main switch is connected to the second end of the second primary winding, the second end of the main switch is grounded, and the The output end of the controller is connected to the control end of the main switch and the control end of the clamping switch;
  • the main switch is turned off, the clamping switch is turned off, and the excitation energy on the primary side of the transformer is not completely released;
  • the main switch is turned off, the clamping switch is turned on, and the excitation energy on the primary side of the transformer has been completely released.
  • the controller when in the current continuous CCM mode, the controller is used to:
  • the main switch is controlled to be turned off, and the delay time is waited for, and then the clamp switch is controlled to be turned on, and the first time period is the period of waiting for the delay time. period.
  • the controller when in discontinuous current DCM mode, is configured to:
  • the main switch When the clamp switch is turned off, the main switch is controlled to be turned off, and when the source-drain voltage of the main switch reaches the Nth peak value, the clamp switch is controlled to be turned on, where N is greater than or an integer equal to 1, the first period of time is the period of time during which the excitation energy of the primary side of the transformer is not completely released in the period of time after the main switch is turned off and before the clamping switch is turned on .
  • controller is used to:
  • the clamp switch When the main switch is turned off and the clamp switch is turned on, if it is detected that the voltages of the first clamp capacitor and the second clamp capacitor drop to a target voltage, the clamp switch is controlled Turn off; the target voltage is matched to half of the secondary reflected voltage.
  • the transformer further includes a secondary winding, and the secondary winding is sandwiched between the first primary winding and the second primary winding to form a sandwich-wound transformer.
  • the switching power supply is a flyback switching power supply or a forward switching power supply.
  • an electronic device including the switching power supply involved in the first aspect and its optional solutions.
  • the two clamp capacitors can be connected in parallel and then discharged. , which effectively limits the current during discharge, and avoids or reduces device damage caused by excessive pulse current.
  • the two clamping capacitors in the present invention are obtained from different positions respectively. Obtaining electrical energy, in turn, can facilitate the reduction of clamp capacitor selection requirements.
  • FIG. 1 is a schematic diagram 1 of the structure of a switching power supply in an embodiment of the present invention.
  • FIG. 2 is a second structural schematic diagram of a switching power supply in an embodiment of the present invention.
  • 3a and 3b are schematic structural diagrams of a transformer in an embodiment of the present invention.
  • FIG. 4 is a schematic diagram 3 of the structure of a switching power supply in an embodiment of the present invention.
  • FIG. 5 is a fourth schematic diagram of the structure of a switching power supply in an embodiment of the present invention.
  • FIG. 6 is a schematic circuit diagram of a switching power supply in an embodiment of the present invention.
  • FIG. 7 is a schematic diagram of a circuit during charging of a clamping capacitor according to an embodiment of the present invention.
  • FIG. 8 is a schematic diagram 1 of a circuit when the clamping capacitor is discharged according to an embodiment of the present invention.
  • FIG. 9 is a second schematic diagram of the circuit when the clamping capacitor is discharged according to an embodiment of the present invention.
  • FIG. 10 is a schematic diagram of a signal of a CCM mode in an embodiment of the present invention.
  • FIG. 11 is a schematic diagram of signals in a CDM mode according to an embodiment of the present invention.
  • a switching power supply includes: an active clamp circuit 1 and a transformer 2 , the active clamp circuit 1 includes a first clamp capacitor C1 and a second clamp capacitor C2 , and may further include: a path guide Module 11.
  • the switching power supply can be a flyback switching power supply or a forward switching power supply. Because it adopts the active clamp circuit 1, it can also be understood as a kind of high-efficiency flyback power supply and forward power supply, in which the leakage inductance energy of the transformer can be sent back to the primary circuit or the secondary output, instead of the general reverse power supply. In addition, the zero-voltage (ZVS) soft switching of the main and auxiliary tubes can be realized, which reduces the switching loss and improves the efficiency.
  • ZVS zero-voltage
  • the path guiding module 11 is respectively connected to both ends of the first clamping capacitor C1 and both ends of the second clamping capacitor C2; the path guiding module 11, the first clamping capacitor C1, the The second clamping capacitors C2 are directly or indirectly connected to the primary side of the transformer 2 .
  • the path guidance module 11 is used for:
  • the primary side of the transformer 2 is discharged after the first clamping capacitor C1 and the second clamping capacitor C2 are connected in parallel.
  • the different positions can be understood as: both circuit positions can provide electric power, and the sources of electric power are different or different.
  • the power obtained from different positions may be obtained from different windings and leakage inductances on the primary side, for example.
  • the clamp switch and the main switch are complementary switches , the zero-voltage switching (ZVS) of the clamp switch and the main switch can be realized, and the resonance of the leakage inductance in the transformer and the clamp capacitor in the active clamp circuit can send the leakage inductance energy to the secondary, which is the active clamp Bit Flyback (ACF) operation.
  • ZVS zero-voltage switching
  • the operation in order to reduce standby power consumption and improve efficiency, generally, the operation is switched from ACF to DCM when the load is light, and the operation is switched from DCM to ACF when the load is heavy to improve the efficiency.
  • the pulse current of the clamp switch and the output capacitor that is, the capacitor connected to the secondary winding of the transformer
  • the clamp switch and output capacitor are at risk of damage. It is not easy to have a common clamp switch and output capacitor, which may cause damage. It can be seen that in this embodiment of the present invention, this risk can be avoided or reduced.
  • the two clamping capacitors in the embodiment of the present invention are obtained.
  • Each of the clamping capacitors obtains power from different positions, and further, it is convenient to reduce the selection requirements of the clamping capacitors. Among them, since the two clamping capacitors are not connected in series to obtain electric energy, there is no need to select clamping capacitors with equal capacities due to the consideration of balanced voltage division.
  • the active clamp circuit 1 further includes a clamp switch 12 (ie, the clamp switch S2 shown in FIGS. 6 to 9 ).
  • the primary side includes a first leakage inductance L1, a first primary winding P1, a second leakage inductance L2 and a second primary winding P2 which are connected in sequence.
  • the first end of the first clamping capacitor C1 is connected to the end of the first leakage inductance L1 away from the first primary winding P1
  • the second end of the second clamping capacitor C2 is connected to the second end of the clamping switch 12 .
  • One end, the second end of the clamp switch 12 is connected to the end of the second primary winding P2 away from the second leakage inductance L2, the path guiding module 11 is connected to the second leakage inductance away from the second primary winding one end;
  • the path guidance module 11 is specifically used for:
  • the first clamping capacitor is guided to obtain power from the first leakage inductance and the first primary winding
  • the second clamping capacitor is guided from the second leakage inductance and the first primary winding.
  • the second primary winding obtains electrical energy
  • the first leakage inductance, the first primary winding, the second leakage inductance and the second leakage inductance are connected in parallel with the first clamping capacitor and the second clamping capacitor in parallel. Primary winding discharges.
  • the two clamping capacitors obtain power from the leakage inductances of different primary windings respectively, the voltage experienced by each clamping capacitor during charging can reach a lower level than the scheme of obtaining power after connecting in series. Therefore, the two clamping capacitors do not need to choose capacitors with higher withstand voltages.
  • the two clamping capacitors need to be configured with equal capacities (if they are not equal, different voltage divisions will occur).
  • chip capacitors are generally used in order to reduce the volume. Considering that the capacitance of this capacitor will be affected by withstand voltage, temperature, etc., the withstand voltage should be at least 250V or more.
  • the transformer 2 further includes a secondary winding S, and the secondary winding S is sandwiched between the first primary winding P1 and the second primary winding P2 time to form a sandwich-wound transformer.
  • the connection end N2 and the connection end N3 are the two terminals of the first primary winding P1
  • the connection end N1 and the connection end N2 are the two terminals of the second primary winding P2
  • the connection end N4 and the connection end N5 are the secondary winding S
  • the two terminals of the secondary winding S can be connected to the output diode D5.
  • the withstand voltage requirement of the clamp capacitor can be effectively reduced.
  • a capacitor of more than 100V can be used.
  • the above sandwich-wound transformer can be mainly used in active clamp counterattack scenarios with high power (for example, application scenarios above 45W), but implementations applied to other scenarios are not excluded.
  • the path guiding module 11 may include a first diode D1 and a second diode D2 .
  • the first end of the first clamping capacitor C1 is connected to the end of the first leakage inductance L1 away from the first primary winding P1, and the negative electrode of the first diode D1 is connected to the second end of the first clamping capacitor C1.
  • Two terminals, the anode of the first diode D1 is connected to the cathode of the second diode D2, and the cathode of the second diode D2 is also connected to the second leakage inductance L2 away from the second primary One end of the winding P2, the anode of the second diode D2 is connected to the first end of the second clamping capacitor C2, and the second end of the second clamping capacitor C2 is connected to the clamping switch 12 (ie The first end of the clamp switch S2 in FIGS. 6 to 9 ), the second end of the clamp switch 12 (ie the clamp switch S2 in FIGS. 6 to 9 ) is connected to the second primary winding P2 away from the One end of the second leakage inductance L2.
  • the first leakage inductance L1, the first primary winding P1, the first diode D1 and the first clamping capacitor C1 form a loop, and further, the leakage inductance energy can be transferred to the first clamping capacitor C1 ;
  • the second leakage inductance L2, the second primary winding P2, the body diode of the clamping switch 12, the second clamping capacitor C2 and the second diode form a loop, and further, the leakage inductance energy can be transferred to the second clamping capacitor C2 .
  • the path guiding module 11 further includes a third diode D3 and a fourth diode D4;
  • the anode of the third diode D3 is connected to the first end of the first clamping capacitor C1, the cathode of the third diode D3 is connected to the first end of the second clamping capacitor C2, and the The anode of the fourth diode D4 is connected to the second end of the first clamping capacitor C1, and the cathode of the fourth diode D4 is connected to the second end of the second clamping capacitor C2.
  • the first terminals of the first clamping capacitor C1 and the second clamping capacitor C2 can be connected in parallel to the first terminal of the first leakage inductance, and the first clamping capacitor C1 and the second clamping capacitor The second end of C2 is connected in parallel with the first end of the clamp switch, forming a circuit state capable of realizing the discharge of the first clamp capacitor C1 and the second clamp capacitor C2.
  • the switching power supply further includes a main switch 3 (ie, the main switch S1 shown in FIGS. 6 to 9 ) and a controller 4 .
  • a main switch 3 ie, the main switch S1 shown in FIGS. 6 to 9
  • a controller 4 One end is connected to the second end of the second primary winding P2, the second end of the main switch 3 is grounded, the output end of the controller 4 is connected to the control end of the main switch 3, and the clamp switch 12 control terminal.
  • the input terminal of the controller 4 can also be connected to other circuit positions, so as to provide a basis for the control of the main switch 3 and the clamp switch 12 .
  • the main switch 3 is turned off, the clamping switch 12 is turned off, and the excitation energy on the primary side of the transformer is not completely released;
  • the main switch 3 is turned off, the clamping switch 12 is turned on, and the excitation energy on the primary side of the transformer has been completely released.
  • S1 is used to represent the main switch
  • S2 is used to represent the clamp switch
  • the related content can be understood by referring to the main switch 3 and the clamp switch 12 above.
  • the first end of the first leakage inductance L1 can be connected to the DC power supply DC, the voltage provided by the DC power supply DC can be, for example, Vin, the DC power supply DC can be, for example, rectified or generated by the alternating current, or is obtained directly.
  • the output side of the transformer can also be connected in parallel with the output capacitor C3.
  • the primary winding of the transformer is divided into two windings, the first primary winding P1 and the second primary winding P2, and the leakage inductance is also divided into two parts: the first leakage inductance L1 and the second leakage inductance L2 .
  • the first clamping capacitor C1 and the first diode D1 form a clamping circuit of the first primary winding P1 and the first leakage inductance L1
  • the second diode D2 and the second clamping capacitor C2 form the second primary winding
  • the third diode D3 constitutes the discharge circuit of the second clamp capacitor C2
  • the fourth diode D4 constitutes the discharge circuit of the first clamp capacitor C1.
  • the clamp switch S2 When the excitation energy is completely released to the secondary, the clamp switch S2 continues to conduct. At this time, the active clamp circuit reversely charges the excitation inductance and leakage inductance of the transformer through two paths, namely:
  • controller 4 shown in FIG. 5 is used for:
  • the input end of the controller 4 can be directly or indirectly connected to the first clamping capacitor and/or the second clamping capacitor to collect the voltage of the clamping capacitor, thereby providing a basis for the above judgment and processing. No matter what method is used for detection, as long as information about the voltage of the clamping capacitor can be obtained, it does not deviate from the scope of the embodiments of the present invention.
  • the clamping S2 is turned off, and the first clamping capacitor is at this time. C1.
  • the leakage inductance energy of the second clamping capacitor C2 is converted into the current of excitation and leakage inductance, that is, electrical energy is converted into magnetic energy, and sent back to the power supply DC.
  • the active clamp circuit can be understood as an active clamp in a parallel mode.
  • the active clamp in parallel mode can be applied to two operating modes: CCM mode and DCM mode. In actual operation, it is possible to mix the two modes for efficiency and to reduce standby power consumption.
  • the operating frequency can also be divided into fixed frequency and variable frequency modes. For the same reason, it may be necessary to mix the two modes.
  • the main switch S1 is turned off at time t0, the current of the second leakage inductance L2 flows through the body diode of the clamping switch S2 and enters the second clamping capacitor C2 for storage, and the current of the first leakage inductance L1 is stored in the second clamping capacitor C2.
  • a certain time delay ie, the delay time
  • the controller 4 shown in FIG. 5 can be used to:
  • the main switch is controlled to be turned off, and the delay time is waited for, and then the clamp switch is controlled to be turned on, and the first time period is the period of waiting for the delay time. period.
  • the controller 4 shown in FIG. 5 can be used to:
  • the main switch When the clamp switch is turned off, the main switch is controlled to be turned off, and when the source-drain voltage of the main switch reaches the Nth peak value, the clamp switch is controlled to be turned on, where N is greater than or an integer equal to 1, the first time period is the time period in which the excitation energy of the primary side of the transformer is not completely released in the time period after the main switch is turned off and before the clamping switch is turned on .
  • the input terminal of the controller 4 can obtain the information of the source-drain voltage of the main switch, and the information can be obtained by directly or indirectly detecting the main switch. depart from the scope of the embodiments of the present invention.
  • Id1 in FIG. 10 and FIG. 11 refers to the drain current of the main switch S1
  • Id2 refers to the drain current of the clamp switch S2 .
  • An embodiment of the present invention provides an electronic device, including the switching power supply involved in the above optional solution.
  • the switching power supply and electronic device provided by the embodiments of the present invention, by introducing a path guiding module into the active clamp circuit and using two clamp capacitors, when the active clamp circuit discharges, the two clamp capacitors can be connected in parallel After discharge, the current during discharge is effectively limited, and device damage caused by excessive pulse current is avoided or reduced.
  • the two clamping capacitors in the present invention are obtained from different positions respectively. Obtaining electrical energy, in turn, can facilitate the reduction of clamp capacitor selection requirements.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)

Abstract

一种开关电源与电子设备，包括：有源钳位电路（1）与变压器（2），所述有源钳位电路（1）包括第一钳位电容（C1）、第二钳位电容（C2），所述有源钳位电路（1）还包括：路径引导模块（11）；所述路径引导模块（11）分别连接所述第一钳位电容（C1）的两端，以及所述第二钳位电容（C2）的两端；所述路径引导模块（11）、所述第一钳位电容（C1）、所述第二钳位电容（C2）均直接或间接连接变压器（2）的初级侧；所述路径引导模块（11）用于：在第一时间段，引导所述第一钳位电容（C1）与所述第二钳位电容（C2）分别自变压器（2）的初级侧的不同位置获取电能；在第二时间段，引导所述第一钳位电容（C1）与所述第二钳位电容（C1）并联后对所述变压器（2）的初级侧放电。

Description

开关电源与电子设备 技术领域
本发明涉及开关电源，尤其涉及一种开关电源与电子设备。
背景技术
开关电源，广泛应用于交流-直流(AC/DC)和直流-直流(DC/DC)转换，并在输入侧和输出侧之间提供绝缘隔离。例如反激式开关电源或正激式开关电源。
现有相关技术中，开关电源中可设有变压器与有源钳位电路，有源钳位电路中可通过钳位电容存储变压器的漏感能量并将其送回至变压器。
然而，在使用现有的有源钳位电路时，易于造成有源钳位电路中钳位开关和/或变压器次级侧所连接的输出二极管电流过大的问题，从而可能会造成钳位开关、输出二极管损坏等问题。具体例如：次级整流管用同步整流管，有源钳位可能造成同步整流管的过早关断，从而降低效率或初次级MOS管共通问题造成损坏。
发明内容
本发明提供一种开关电源与电子设备，以解决可能会造成钳位开关、输出二极管损坏的问题。
根据本发明的第一方面，提供了一种开关电源，包括：有源钳位电路与变压器，所述有源钳位电路包括第一钳位电容、第二钳位电容，其特征在于，所述有源钳位电路还包括：路径引导模块；所述路径引导模块分别连接所述第一钳位电容的两端，以及所述第二钳位电容的两端；所述路径引导模块、所述第一钳位电容、所述第二钳位电容均连接变压器的初级侧；
所述路径引导模块用于：
在第一时间段，引导所述第一钳位电容与所述第二钳位电容分别自变压器的初级侧的不同位置获取电能；
在第二时间段，引导所述第一钳位电容与所述第二钳位电容并联后对所 述变压器的初级侧放电。
可选的，所述有源钳位电路还包括钳位开关，所述变压器的初级侧包括依次连接的第一漏感、第一初级绕组、第二漏感与第二初级绕组；
所述第一钳位电容的第一端连接所述第一漏感远离第一初级绕组的一端，所述第二钳位电容的第二端连接所述钳位开关的第一端，所述钳位开关的第二端连接所述第二初级绕组远离第二漏感的一端，所述路径引导模块连接所述第二漏感远离所述第二初级绕组的一端；
所述路径引导模块具体用于：
在第一时间段，引导所述第一钳位电容自所述第一漏感与所述第一初级绕组获取电能，并引导所述第二钳位电容自所述第二漏感与所述第二初级绕组获取电能；
在第二时间段，引导所述第一钳位电容与所述第二钳位电容并联后对所述第一漏感、所述第一初级绕组、所述第二漏感与所述第二初级绕组放电。
可选的，所述路径引导模块包括第一二极管与第二二极管；
所述第一钳位电容的第一端连接所述第一漏感远离第一初级绕组的一端，所述第一二极管的负极连接所述第一钳位电容的第二端，所述第一二极管的正极连接所述第二二极管的负极，所述第二二极管的负极还连接所述第二漏感远离所述第二初级绕组的一端，所述第二二极管的正极连接所述第二钳位电容的第一端，所述第二钳位电容的第二端连接所述钳位开关的第一端，所述钳位开关的第二端连接所述第二初级绕组远离第二漏感的一端。
可选的，所述路径引导模块还包括第三二极管与第四二极管；
所述第三二极管的正极连接所述第一钳位电容的第一端，所述第三二极管的负极连接所述第二钳位电容的第一端，所述第四二极管的正极连接所述第一钳位电容的第二端，所述第四二极管的负极连接所述第二钳位电容的第二端。
可选的，所述的开关电源，还包括主开关与控制器，所述主开关的第一端连接所述第二初级绕组的第二端，所述主开关的第二端接地，所述控制器的输出端连接所述主开关的控制端，以及所述钳位开关的控制端；
处于所述第一时间段时，所述主开关关断、所述钳位开关关断，且所述变压器的初级侧的励磁能量未被完全释放；
处于所述第二时间段时，所述主开关关断、所述钳位开关导通，且所述变压器的初级侧的励磁能量已被完全释放。
可选的，在处于电流连续CCM模式时，所述控制器用于：
在所述钳位开关关断的情况下，控制所述主开关关断，并等待延时时长，然后控制所述钳位开关导通，所述第一时间段为等待所述延时时长的时间段。
可选的，在处于电流断续DCM模式时，所述控制器用于：
在所述钳位开关关断的情况下，控制所述主开关关断，并在所述主开关源漏电压到达第N个峰值时，控制所述钳位开关导通，其中的N为大于或等于1的整数，所述第一时间段为所述主开关关断后且所述钳位开关导通前的时间段中，所述变压器的初级侧的励磁能量未被完全释放的时间段。
可选的，所述控制器用于：
在所述主开关关断，且所述钳位开关导通时，若检测到所述第一钳位电容与所述第二钳位电容的电压下降至目标电压，则控制所述钳位开关关断；所述目标电压匹配于次级反射电压的一半。
可选的，所述变压器还包括次级绕组，所述次级绕组夹于所述第一初级绕组与所述第二初级绕组之间，以形成三明治绕法的变压器。
可选的，所述开关电源为反激式开关电源或正激式开关电源。
根据本发明的第二方面，提供了一种电子设备，包括第一方面及其可选方案涉及的开关电源。
本发明提供的开关电源与电子设备中，通过在有源钳位电路中引入路径引导模块，并采用两个钳位电容，有源钳位电路放电时，可使得两个钳位电容并联后放电，有效限制了放电时的电流，避免或减轻了脉冲电流过大而导致的器件损坏。
同时，相较于两个钳位电容串联后自变压器的一个电路位置(例如两个电容串联后自单一漏感与绕组获取电能)的方案，本发明中的两个钳位电容分别自不同位置获取电能，进而，可便于降低钳位电容的选择要求。
例如：由于两者并非串联后获取电能的，无需因为均衡分压的考虑而选择容量相等的钳位电容，再例如：在进一步方案中，由于两个钳位电容分别是自不同初级绕组的漏感获取电能的，相对于串联后获取电能的方案，每个 钳位电容在充电时所经受的电压可以达到较低的水平，故而，两个钳位电容无需选择耐压较高的电容。
附图说明
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动性的前提下，还可以根据这些附图获得其他的附图。
图1是本发明一实施例中开关电源的构造示意图一；
图2是本发明一实施例中开关电源的构造示意图二；
图3a与图3b是本发明一实施例中变压器的构造示意图；
图4是本发明一实施例中开关电源的构造示意图三；
图5是本发明一实施例中开关电源的构造示意图四；
图6是本发明一实施例中开关电源的电路示意图；
图7是本发明一实施例中钳位电容充电时的电路示意图；
图8是本发明一实施例中钳位电容放电时的电路示意图一；
图9是本发明一实施例中钳位电容放电时的电路示意图二；
图10是本发明一实施例中CCM模式的信号示意图；
图11是本发明一实施例中CDM模式的信号示意图。
附图标记说明：
1-有源钳位电路；
11-路径引导模块；
12、S2-钳位开关；
2-变压器；
3、S1-主开关；
4-控制器；
C1-第一钳位电容；
C2-第二钳位电容；
C3-输出电容；
D1-第一二极管；
D2-第二二极管；
D3-第三二极管；
D4-第四二极管；
D5-输出二极管；
P1-第一初级绕组；
P2-第二初级绕组；
S-次级绕组；
L1-第一漏感；
L2-第二漏感。
具体实施方式
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
本发明的说明书和权利要求书及上述附图中的术语“第一”、“第二”、“第三”“第四”等(如果存在)是用于区别类似的对象，而不必用于描述特定的顺序或先后次序。应该理解这样使用的数据在适当情况下可以互换，以便这里描述的本发明的实施例能够以除了在这里图示或描述的那些以外的顺序实施。此外，术语“包括”和“具有”以及他们的任何变形，意图在于覆盖不排他的包含，例如，包含了一系列步骤或单元的过程、方法、系统、产品或设备不必限于清楚地列出的那些步骤或单元，而是可包括没有清楚地列出的或对于这些过程、方法、产品或设备固有的其它步骤或单元。
下面以具体地实施例对本发明的技术方案进行详细说明。下面这几个具体的实施例可以相互结合，对于相同或相似的概念或过程可能在某些实施例不再赘述。
请参考图1，开关电源，包括：有源钳位电路1与变压器2，所述有源钳位电路1包括第一钳位电容C1、第二钳位电容C2，进一步还可包括：路径引导模块11。
其中的开关电源可以是反激式开关电源，也可以是正激式开关电源。因其采用了有源钳位电路1，故而，也可理解为一种高效反激电源、正激电源，其中，可以把变压器漏感能量送回初级电路或次级输出，而不是像一般反激电路浪费掉，除此之外，还可以实现主管和副管的零电压(ZVS)软开关，降低了开关损耗、提升了效率。
所述路径引导模块11分别连接所述第一钳位电容C1的两端，以及所述第二钳位电容C2的两端；所述路径引导模块11、所述第一钳位电容C1、所述第二钳位电容C2均直接或间接连接变压器2的初级侧。
所述路径引导模块11用于：
在第一时间段，引导所述第一钳位电容C1与所述第二钳位电容C2分别自变压器的初级侧的不同位置获取电能；
在第二时间段，引导所述第一钳位电容C1与所述第二钳位电容C2并联后对所述变压器2的初级侧放电。
其中的不同位置，可理解为：两个电路位置均能够提供电能，且提供电能的来源是不同或具有差别的。具体举例中，不同位置获取电能，可例如是自初级侧的不同绕组、漏感获取到的。
以上方案中，通过在有源钳位电路中引入路径引导模块，并采用两个钳位电容，有源钳位电路放电时，可使得两个钳位电容并联后放电，有效限制了放电时的电流，避免或减轻了脉冲电流过大而导致的器件损坏。
针对于该过大的脉冲电流，在现有的相关技术中，开关电源中，钳位开关与主开关(例如图6至图9所示的主开关S1和钳位开关S2)为互补的开关，可实现钳位开关与主开关的零电压开关(ZVS)，并且变压器中漏感与有源钳位电路中的钳位电容的谐振可将漏感能量送到次级，这就是有源钳位反激(ACF)的操作。
现有相关技术中，为了降低待机功耗和提高效率，一般轻载时会从ACF转到DCM操作，负载加重时则从DCM转到ACF工作以提高效率。但从DCM到ACF转换的第一个脉冲，存在钳位开关、输出电容(即连接变压器次级绕组的电容)的脉冲电流大的问题，钳位开关、输出电容有损坏的风险，如果时序控制不好易存在钳位开关、输出电容的共通，引起损坏。可见，本发明实施例中，可避免或降低该风险。
同时，本发明实施例中，相较于两个钳位电容串联后自变压器的一个电路位置(例如两个电容串联后自单一漏感与绕组获取电能)的方案，本发明实施例中的两个钳位电容分别自不同位置获取电能，进而，可便于降低钳位电容的选择要求。其中，由于两个钳位电容并非串联后获取电能的，无需因为均衡分压的考虑而选择容量相等的钳位电容。
其中一种实施方式中，请参考图2至图5，所述有源钳位电路1还包括钳位开关12(即图6至图9所示的钳位开关S2)，所述变压器2的初级侧包括依次连接的第一漏感L1、第一初级绕组P1、第二漏感L2与第二初级绕组P2。
所述第一钳位电容C1的第一端连接所述第一漏感L1远离第一初级绕组P1的一端，所述第二钳位电容C2的第二端连接所述钳位开关12的第一端，所述钳位开关12的第二端连接所述第二初级绕组P2远离第二漏感L2的一端，所述路径引导模块11连接所述第二漏感远离所述第二初级绕组的一端；
所述路径引导模块11具体用于：
在第一时间段，引导所述第一钳位电容自所述第一漏感与所述第一初级绕组获取电能，并引导所述第二钳位电容自所述第二漏感与所述第二初级绕组获取电能；
在第二时间段，引导所述第一钳位电容与所述第二钳位电容并联后对所述第一漏感、所述第一初级绕组、所述第二漏感与所述第二初级绕组放电。
在以上方案中，由于两个钳位电容分别是自不同初级绕组的漏感获取电能的，相对于串联后获取电能的方案，每个钳位电容在充电时所经受的电压可以达到较低的水平，故而，两个钳位电容无需选择耐压较高的电容。
相较而言，若采用“两个电容串联后自单一漏感与绕组获取电能”的方案，则两个钳位电容需配置为容量相等(若不相等，则会造成不同分压)，在该电路中，为了减小体积一般采用贴片瓷片电容，考虑到这种电容容量会受耐压、温度等影响，耐压至少要选250V以上的电容。
其中一种实施方式中，请参考图3a与图3b，所述变压器2还包括次级绕组S，所述次级绕组S夹于所述第一初级绕组P1与所述第二初级绕组P2之间，以形成三明治绕法的变压器。其中，连接端N2与连接端N3为第一 初级绕组P1的两个端子，连接端N1与连接端N2为第二初级绕组P2的两个端子，连接端N4与连接端N5为次级绕组S的两个端子，次级绕组S可连接输出二极管D5。
以上方案中，结合有源钳位电路的构造，以及三明治绕法的变压器，可有效降低钳位电容的耐压需求，例如：在此基础上，采用100V以上的电容即可。同时，以上三明治绕法的变压器，可主要用于功率较大的有源钳位反击场景(例如45W以上的应用场景)，但也不排除应用于其他场景的实施方式。
其中一种实施方式中，请参考图4，所述路径引导模块11可以包括第一二极管D1与第二二极管D2。
所述第一钳位电容C1的第一端连接所述第一漏感L1远离第一初级绕组P1的一端，所述第一二极管D1的负极连接所述第一钳位电容C1的第二端，所述第一二极管D1的正极连接所述第二二极管D2的负极，所述第二二极管D2的负极还连接所述第二漏感L2远离所述第二初级绕组P2的一端，所述第二二极管D2的正极连接所述第二钳位电容C2的第一端，所述第二钳位电容C2的第二端连接所述钳位开关12(即图6至图9中的钳位开关S2)的第一端，所述钳位开关12(即图6至图9中的钳位开关S2)的第二端连接所述第二初级绕组P2远离第二漏感L2的一端。
其中，在第一时间段，第一漏感L1、第一初级绕组P1、第一二极管D1与第一钳位电容C1形成回路，进而，漏感能量能够输送至第一钳位电容C1；第二漏感L2、第二初级绕组P2、钳位开关12的体二极管、第二钳位电容C2与第二二极管形成回路，进而，漏感能量能够输送至第二钳位电容C2。
请参考图3，所述路径引导模块11还包括第三二极管D3与第四二极管D4；
所述第三二极管D3的正极连接所述第一钳位电容C1的第一端，所述第三二极管D3的负极连接所述第二钳位电容C2的第一端，所述第四二极管D4的正极连接所述第一钳位电容C1的第二端，所述第四二极管D4的负极连接所述第二钳位电容C2的第二端。
其中，在第二时间段，第一钳位电容C1与第二钳位电容C2的第一端 可并联连接于第一漏感的第一端，第一钳位电容C1与第二钳位电容C2的第二端并联连接于钳位开关的第一端，形成能够实现第一钳位电容C1、第二钳位电容C2放电的电路状态。
其中一种实施方式中，请参考图5，所述的开关电源，还包括主开关3(即图6至图9中所示的主开关S1)与控制器4，所述主开关3的第一端连接所述第二初级绕组P2的第二端，所述主开关3的第二端接地，所述控制器4的输出端连接所述主开关3的控制端，以及所述钳位开关12的控制端。
此外，控制器4的输入端还可连接其他电路位置，从而为主开关3、钳位开关12的控制提供依据。
处于所述第一时间段时，所述主开关3关断、所述钳位开关12关断，且所述变压器的初级侧的励磁能量未被完全释放；
处于所述第二时间段时，所述主开关3关断、所述钳位开关12导通，且所述变压器的初级侧的励磁能量已被完全释放。
以下将结合图6至图11对一种举例中开关电源的控制过程进行阐述。同时，以下利用S1来表征主开关，利用S2来表征钳位开关，其相关内容均可参照语前文的主开关3与钳位开关12理解。
请参考图6至图9，第一漏感L1的第一端可连接直流电源DC，该直流电源DC所提供的电压可例如Vin，直流电源DC可例如是对交流电整流或产生的，也可以是直接获取到的。变压器输出侧还可并联输出电容C3。
基于图6至图9所示的电路结构，变压器初级绕组分为第一初级绕组P1、第二初级绕组P2两个绕组，漏感也分为第一漏感L1、第二漏感L2两部分。第一钳位电容C1与第一二极管D1构成了第一初级绕组P1和第一漏感L1的钳位电路，第二二极管D2与第二钳位电容C2构成了第二初级绕组P2和第二漏感L2的吸收回路，第三二极管D3构成了第二钳位电容C2的放电回路，第四二极管D4构成了第一钳位电容C1的放电回路。
在主开关S1关断时刻，电路的工作原理可参考图7所示，一半初级的电流流经第一漏感L1，第一初级绕组P1、第一二极管D1、第一钳位电容C1，第一漏感L1的能量储存在第一钳位电容C1，另一半初级的电流流经第二漏感L2、第二初级绕组P2、钳位开关S2的体二极管、第二钳位电容C2 与第二二极管D2，第二漏感L2的能量储存在第二钳位电容C2中。
当励磁能量完全释放到次级后钳位开关S2继续导通，此时，有源钳位电路通过两个路径给变压器励磁电感和漏感反向充电，即：
图8所示的一个路径：第一钳位电容C1-第四二极管D4-钳位开关S2-第二初级绕组P2-第二漏感L2-第一初级绕组P1-第一漏感L1-第一钳位电容C1；
图9所示的另一个路径：第二钳位电容C2-钳位开关S2-第二初级绕组P2-第二漏感L2-第一初级绕组P1-第二漏感L1-第三二极管D3-第二钳位电容C2。
其中一种实施方式中，图5所示的控制器4用于：
在所述主开关S1关断，且所述钳位开关S2导通时，若检测到所述第一钳位电容C1与所述第二钳位电容C2的电压下降至目标电压，则控制所述钳位开关关断；所述目标电压匹配于次级反射电压的一半。
其中，控制器4的输入端可直接或间接连接第一钳位电容和/或第二钳位电容，以采集钳位电容的电压，从而为以上判断和处理提供依据。不论采用何种方式检测，只要能获取到钳位电容的电压的信息，就不脱离本发明实施例的范围。
具体举例中，当第一钳位电容C1与第二钳位电容C2的电压释放到次级反射电压的一半时(0.5*N*Vout)，关断钳位S2，此时第一钳位电容C1、第二钳位电容C2的漏感能量转换为励磁和漏感的电流，即电能转换给磁能，送回电源DC。
从上述描述可以看出，主开关S1关断时，第一漏感L1给第一钳位电容C1充电，第二漏感L2给第二钳位电容C2充电，漏感能量回放时，第二钳位电容C2和第一钳位电容C1并联，故而，该有源钳位电路可理解为并联模式的有源钳位。
并联模式的有源钳位具体应用时可应用于两种工作模式：CCM模式和DCM模式。实际运行时为了效率和降低待机功耗，有可能两种模式混合操作。工作频率也可以分为定频和变频模式，同样的原因，可能需要两种模式混合工作。
以下将结合具体的波形来描述CCM模式(变频)和DCM模式(定 频)操作。
请参考图10，CCM模式的波形中，t0时刻主开关S1关断，第二漏感L2的电流流过钳位开关S2的体二极管进入第二钳位电容C2储存，第一漏感L1的电流通过第一二极管D1进入第一钳位电容C1储存，钳位开关S2可以在t0后延时一定时刻(即延时时长)打开；t1时刻漏感能量释放完毕，励磁电流换流到次级；t2时刻励磁能量释放完毕，此时第一钳位电容C1与第二钳位电容C23并联给励磁电感放电；t3时刻关断钳位开关S2，此时主开关S1的漏极电流Id2会给主开关S1的源漏电压Vds放电；t4时刻源漏电压Vds到零，导通主开关S1实现零电压开通(ZVS)；t5时刻下一个周期开始。当负载和输入电压不同时t1-t2，t4-t5的时间都会变化，所以频率也会变化。当主开关S1由于某种原因不能实现ZVS时，可以相应调整t2-t3的时间来实现。
为实现以上过程中导通钳位开关的动作，在处于电流连续CCM模式时，图5所示的控制器4可用于：
在所述钳位开关关断的情况下，控制所述主开关关断，并等待延时时长，然后控制所述钳位开关导通，所述第一时间段为等待所述延时时长的时间段。
请参考图11，DCM模式中的大部分波形与CCM模式类似，只是钳位开关S2的导通时刻在源漏电压Vds自由振荡的峰值，可以在第1，2，3，4等峰值，不在峰值也可以工作，但钳位开关S2有一些开通损耗。当主开关S1由于某种原因不能实现ZVS时，可以通过调整t2-t3的时间来保证主开关S1实现ZVS，由于时间变化比较小，可以基本保持频率恒定。
为实现以上过程中导通钳位开关的动作，在处于电流连续DCM模式时，图5所示的控制器4可用于：
在所述钳位开关关断的情况下，控制所述主开关关断，并在所述主开关源漏电压到达第N个峰值时，控制所述钳位开关导通，其中的N为大于或等于1的整数，所述第一时间段为所述主开关关断后且所述钳位开关导通前的时间段中，所述变压器的初级侧的励磁能量未被完全释放的时间段。
其中，控制器4的输入端可获取主开关的源漏电压的信息，该信息可直接或间接对主开关进行检测而获取到，不论采用何种方式检测，只要能获取 到该信息，就不脱离本发明实施例的范围。
此外，图10与图11中的Id1指主开关S1的漏极电流，Id2指钳位开关S2的漏极电流。
本发明实施例提供了一种电子设备，包括以上可选方案涉及的开关电源。
本发明实施例提供的开关电源与电子设备中，通过在有源钳位电路中引入路径引导模块，并采用两个钳位电容，有源钳位电路放电时，可使得两个钳位电容并联后放电，有效限制了放电时的电流，避免或减轻了脉冲电流过大而导致的器件损坏。
同时，相较于两个钳位电容串联后自变压器的一个电路位置(例如两个电容串联后自单一漏感与绕组获取电能)的方案，本发明中的两个钳位电容分别自不同位置获取电能，进而，可便于降低钳位电容的选择要求。
最后应说明的是：以上各实施例仅用以说明本发明的技术方案，而非对其限制；尽管参照前述各实施例对本发明进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分或者全部技术特征进行等同替换；而这些修改或者替换，并不使相应技术方案的本质脱离本发明各实施例技术方案的范围。

Claims (10)

  1. 一种开关电源，包括：有源钳位电路与变压器，所述有源钳位电路包括第一钳位电容、第二钳位电容，其特征在于，所述有源钳位电路还包括：路径引导模块；所述路径引导模块分别连接所述第一钳位电容的两端，以及所述第二钳位电容的两端；所述路径引导模块、所述第一钳位电容、所述第二钳位电容均直接或间接连接变压器的初级侧；
    所述路径引导模块用于：
    在第一时间段，引导所述第一钳位电容与所述第二钳位电容分别自变压器的初级侧的不同位置获取电能；
    在第二时间段，引导所述第一钳位电容与所述第二钳位电容并联后对所述变压器的初级侧放电。
  2. 根据权利要求1所述的开关电源，其特征在于，所述有源钳位电路还包括钳位开关，所述变压器的初级侧包括依次连接的第一漏感、第一初级绕组、第二漏感与第二初级绕组；
    所述第一钳位电容的第一端连接所述第一漏感远离第一初级绕组的一端，所述第二钳位电容的第二端连接所述钳位开关的第一端，所述钳位开关的第二端连接所述第二初级绕组远离第二漏感的一端，所述路径引导模块连接所述第二漏感远离所述第二初级绕组的一端；
    所述路径引导模块具体用于：
    在第一时间段，引导所述第一钳位电容自所述第一漏感与所述第一初级绕组获取电能，并引导所述第二钳位电容自所述第二漏感与所述第二初级绕组获取电能；
    在第二时间段，引导所述第一钳位电容与所述第二钳位电容并联后对所述第一漏感、所述第一初级绕组、所述第二漏感与所述第二初级绕组放电。
  3. 根据权利要求2所述的开关电源，其特征在于，所述路径引导模块包括第一二极管与第二二极管；
    所述第一钳位电容的第一端连接所述第一漏感远离第一初级绕组的一端，所述第一二极管的负极连接所述第一钳位电容的第二端，所述第一二极管的正极连接所述第二二极管的负极，所述第二二极管的负极还连接所述第二漏感远离所述第二初级绕组的一端，所述第二二极管的正极连接所述第二 钳位电容的第一端，所述第二钳位电容的第二端连接所述钳位开关的第一端，所述钳位开关的第二端连接所述第二初级绕组远离第二漏感的一端。
  4. 根据权利要求2所述的开关电源，其特征在于，所述路径引导模块还包括第三二极管与第四二极管；
    所述第三二极管的正极连接所述第一钳位电容的第一端，所述第三二极管的负极连接所述第二钳位电容的第一端，所述第四二极管的正极连接所述第一钳位电容的第二端，所述第四二极管的负极连接所述第二钳位电容的第二端。
  5. 根据权利要求2至4任一项所述的开关电源，其特征在于，还包括主开关与控制器，所述主开关的第一端连接所述第二初级绕组的第二端，所述主开关的第二端接地，所述控制器的输出端连接所述主开关的控制端，以及所述钳位开关的控制端；
    处于所述第一时间段时，所述主开关关断、所述钳位开关关断，且所述变压器的初级侧的励磁能量未被完全释放；
    处于所述第二时间段时，所述主开关关断、所述钳位开关导通，且所述变压器的初级侧的励磁能量已被完全释放。
  6. 根据权利要求5所述的开关电源，其特征在于，在处于电流连续CCM模式时，所述控制器用于：
    在所述钳位开关关断的情况下，控制所述主开关关断，并等待延时时长，然后控制所述钳位开关导通，所述第一时间段为等待所述延时时长的时间段。
  7. 根据权利要求6所述的开关电源，其特征在于，在处于电流断续DCM模式时，所述控制器用于：
    在所述钳位开关关断的情况下，控制所述主开关关断，并在所述主开关源漏电压到达第N个峰值时，控制所述钳位开关导通，其中的N为大于或等于1的整数，所述第一时间段为所述主开关关断后且所述钳位开关导通前的时间段中，所述变压器的初级侧的励磁能量未被完全释放的时间段。
  8. 根据权利要求6所述的开关电源，其特征在于，所述控制器用于：
    在所述主开关关断，且所述钳位开关导通时，若检测到所述第一钳位电容与所述第二钳位电容的电压下降至目标电压，则控制所述钳位开关关断； 所述目标电压匹配于次级反射电压的一半。
  9. 根据权利要求2至4任一项所述的开关电源，其特征在于，所述变压器还包括次级绕组，所述次级绕组夹于所述第一初级绕组与所述第二初级绕组之间，以形成三明治绕法的变压器。
  10. 一种电子设备，其特征在于，包括权利要求1至9任一项所述的开关电源。
PCT/CN2020/135487 2020-10-15 2020-12-10 开关电源与电子设备 WO2022077751A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US17/434,295 US11837950B2 (en) 2020-10-15 2020-12-10 Switching power supply and electronic device

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202011102435.9 2020-10-15
CN202011102435.9A CN112152457B (zh) 2020-10-15 2020-10-15 开关电源与电子设备

Publications (1)

Publication Number Publication Date
WO2022077751A1 true WO2022077751A1 (zh) 2022-04-21

Family

ID=73951958

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/135487 WO2022077751A1 (zh) 2020-10-15 2020-12-10 开关电源与电子设备

Country Status (3)

Country Link
US (1) US11837950B2 (zh)
CN (1) CN112152457B (zh)
WO (1) WO2022077751A1 (zh)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101325375A (zh) * 2008-04-02 2008-12-17 刘小荷 双晶正激有源钳位开关电源
US20170070152A1 (en) * 2015-09-03 2017-03-09 Fairchild (Taiwan) Corporation Control circuits and methods for active-clamp flyback power converters
CN107994762A (zh) * 2017-11-21 2018-05-04 浙江万胜智能科技股份有限公司 一种开关电源的无损吸收电路及开关电源
CN209375473U (zh) * 2019-02-19 2019-09-10 广州金升阳科技有限公司 一种反激电路
CN210120487U (zh) * 2019-04-30 2020-02-28 茂硕电源科技股份有限公司 钳位电路和反激变换器
CN111030462A (zh) * 2019-08-26 2020-04-17 广州金升阳科技有限公司 一种有源钳位反激变换器及控制方法

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3201324B2 (ja) * 1997-12-22 2001-08-20 株式会社村田製作所 スイッチング電源装置
US5883795A (en) * 1998-04-28 1999-03-16 Lucent Technologies Inc. Clamp circuit for a power converter and method of operation thereof
US8107268B2 (en) * 2009-09-09 2012-01-31 City University Of Hong Kong Passive lossless snubber cell for a power converter
CN101702578B (zh) * 2009-12-07 2012-01-11 浙江大学 耦合电感实现正反激隔离式升压型变换器及应用
KR20150026470A (ko) * 2013-09-03 2015-03-11 삼성전자주식회사 광원 구동장치, 디스플레이장치 및 그 구동방법
GB2523386B (en) * 2014-02-24 2016-07-06 Tdk-Lambda Uk Ltd Snubber
US9774270B2 (en) * 2015-06-15 2017-09-26 Apple Inc. Systems and methods of operation for power converters having series-parallel mode active clamps
US9923472B1 (en) * 2016-09-07 2018-03-20 Apple Inc. Fixed frequency series-parallel mode (SPM) active clamp flyback converter
WO2019082018A1 (en) * 2017-10-27 2019-05-02 Silanna Asia Pte Ltd DIRECT TRANSFER CONVERTER WITH FUSED VOLTAGE DIVIDER
CN209562410U (zh) * 2019-02-19 2019-10-29 广州金升阳科技有限公司 一种反激变换器

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101325375A (zh) * 2008-04-02 2008-12-17 刘小荷 双晶正激有源钳位开关电源
US20170070152A1 (en) * 2015-09-03 2017-03-09 Fairchild (Taiwan) Corporation Control circuits and methods for active-clamp flyback power converters
CN107994762A (zh) * 2017-11-21 2018-05-04 浙江万胜智能科技股份有限公司 一种开关电源的无损吸收电路及开关电源
CN209375473U (zh) * 2019-02-19 2019-09-10 广州金升阳科技有限公司 一种反激电路
CN210120487U (zh) * 2019-04-30 2020-02-28 茂硕电源科技股份有限公司 钳位电路和反激变换器
CN111030462A (zh) * 2019-08-26 2020-04-17 广州金升阳科技有限公司 一种有源钳位反激变换器及控制方法

Also Published As

Publication number Publication date
US20230308010A1 (en) 2023-09-28
CN112152457B (zh) 2021-05-25
CN112152457A (zh) 2020-12-29
US11837950B2 (en) 2023-12-05

Similar Documents

Publication Publication Date Title
US5946200A (en) Circulating current free type high frequency soft switching pulsewidth modulated full bridge DC/DC converter
TWI474572B (zh) 電源轉換器及輸入電容的電壓平衡方法
US10686387B2 (en) Multi-transformer LLC resonant converter circuit
US20050243579A1 (en) Power system having multiple power converters with reduced switching loss
CN114301301A (zh) 一种宽范围谐振式软开关双向直流变换器及其控制方法
CN105281576A (zh) 准谐振半桥转换器及其控制方法
KR20180004675A (ko) 보조 lc 공진 회로를 갖는 양방향 컨버터 및 그 구동 방법
TWI578676B (zh) 電能轉換系統
US20140192562A1 (en) Single stage ac/dc converter
US11764693B2 (en) Dual-capacitor resonant circuit for use with quasi-resonant zero-current-switching DC-DC converters
US20240113631A1 (en) Control Method of ZVS Flyback Using Transformer Auxiliary Winding
US9356527B2 (en) Multi-mode active clamping power converter
US6239989B1 (en) Forward converter with improved reset circuitry
CN115021544A (zh) 一种钳位模块及开关电源
CN114070090A (zh) 一种串联型有源钳位的反激变换器电路
TW202247587A (zh) 適用於寬範圍輸出電壓的變換器及其控制方法
CN108964473A (zh) 一种高效率高压电源变换电路
CN103782499A (zh) 具有正弦波变压器电压的隔离开关模式dc/dc转换器
CN102290975A (zh) 功率因数校正器及其驱动方法
WO2020134313A1 (zh) 全桥电路及全桥变换器
WO2022077751A1 (zh) 开关电源与电子设备
CN214799290U (zh) 反激式变换器的吸收电路
CN115021578A (zh) 一种反激变换器的控制方法、装置及反激变换器
TWM522514U (zh) 電能轉換系統
CN210780555U (zh) 一种开关变换器

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20957525

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20957525

Country of ref document: EP

Kind code of ref document: A1