CN217824740U - Flyback zero-voltage soft switching circuit with auxiliary winding - Google Patents

Flyback zero-voltage soft switching circuit with auxiliary winding Download PDF

Info

Publication number
CN217824740U
CN217824740U CN202221735802.3U CN202221735802U CN217824740U CN 217824740 U CN217824740 U CN 217824740U CN 202221735802 U CN202221735802 U CN 202221735802U CN 217824740 U CN217824740 U CN 217824740U
Authority
CN
China
Prior art keywords
auxiliary winding
capacitor
diode
winding
transformer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202221735802.3U
Other languages
Chinese (zh)
Inventor
陈康生
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shenzhen Huaige Xinchuang Electronic Technology Co ltd
Original Assignee
Shenzhen Huaige Xinchuang Electronic Technology Co ltd
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 Shenzhen Huaige Xinchuang Electronic Technology Co ltd filed Critical Shenzhen Huaige Xinchuang Electronic Technology Co ltd
Priority to CN202221735802.3U priority Critical patent/CN217824740U/en
Application granted granted Critical
Publication of CN217824740U publication Critical patent/CN217824740U/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

The embodiment of the utility model discloses flyback zero voltage soft switch circuit with auxiliary winding, including magnetizing inductance Lm, transformer T R Switch tube S 1 Switch tube S 2 Diode D and capacitor C 0 Capacitor C 1 And a resistance R 0 Magnetizing inductance Lm and transformer T R Primary side of the switching tube S 1 The source electrode of the power supply is connected with the cathode of the power supply; transformer T R The secondary side of (a) comprises an output winding and an auxiliary winding; switch tube S 2 Of the source connected to the output windingOne end, drain electrode passing through capacitor C 1 The other end of the output winding is connected; the anode of the diode D is connected with one end of the auxiliary winding, and the cathode of the diode D passes through the resistor R 0 The other end of the auxiliary winding is connected; capacitor C 0 And a resistance R 0 Are connected in parallel. The utility model discloses not only can solve hard switching loss problem, capacitive in the hard switching converter and open problem, perception turn-off problem and diode reverse recovery problem, but also can solve the EMI scheduling problem that arouses by hard switch.

Description

Flyback zero-voltage soft switching circuit with auxiliary winding
Technical Field
The utility model relates to a flyback circuit topology technical field especially relates to a take auxiliary winding's flyback zero voltage soft switch circuit.
Background
The current flyback circuit topology generally has low power, low frequency and low efficiency, and compared with other topology circuits, the flyback circuit topology has larger volume for realizing the same power, and the main reasons are that the flyback circuit topology generally works in a hard switching state, has lower efficiency and larger loss ratio.
Miniaturization is a goal sought by current power supply products. And the volume of the components such as inductance, capacitance and the like can be reduced by increasing the switching frequency. However, the bottleneck of increasing the switching frequency is the switching loss of the switching device, so that the soft switching technology is developed.
SUMMERY OF THE UTILITY MODEL
The embodiment of the utility model provides a technical problem that will solve lies in, provides a take auxiliary winding's flyback zero voltage soft switch circuit to improve power conversion efficiency.
In order to solve the technical problem, an embodiment of the utility model provides a take auxiliary winding's flyback zero voltage soft switch circuit, including magnetizing inductance Lm, transformer T R Switch tube S 1 Switch tube S 2 Diode D and capacitor C 0 Capacitor C 1 And a resistance R 0 Magnetizing inductance Lm and transformer T R Primary side of the switching tube S 1 The source electrode of the power supply is connected with the negative electrode of the power supply; one end of the excitation inductor Lm is connected with the anode of the power supply, and the other end is connected with the switch tube S 1 A drain electrode of (1); transformer T R The secondary side of (a) comprises an output winding and an auxiliary winding; switch tube S 2 Is connected to one end of the output winding, and has a drain electrode connected to the output winding via a capacitor C 1 The other end of the output winding is connected; the anode of the diode D is connected with one end of the auxiliary winding, and the cathode of the diode D passes through the resistor R 0 The other end of the auxiliary winding is connected; capacitor C 0 And a resistance R 0 Are connected in parallel.
Further, the output winding and the auxiliary winding have the same number of turns.
The utility model has the advantages that: the utility model discloses through additional a winding, make the excitation inductance current reverse, thereby create the ZVS soft switch condition of flyback circuit main switch; the soft switching technology is one of important technologies for enabling the power converter to be high-frequency, small in size and also one of important ways for improving the power conversion efficiency; when the current naturally crosses zero, the device is turned off (or turned on when the voltage is zero), so that the switching loss is reduced; the utility model discloses not only can solve hard switching loss problem, capacitive in the hard switching converter and open problem, perception turn-off problem and diode reverse recovery problem, but also can solve the EMI scheduling problem that arouses by hard switch.
Drawings
Fig. 1 is a circuit diagram of a flyback zero voltage soft switching circuit with an auxiliary winding according to an embodiment of the present invention.
Fig. 2 (a) is a circuit working waveform diagram of the flyback zero-voltage soft switching circuit with the auxiliary winding in the light load, and fig. 2 (b) is a circuit working waveform diagram of the flyback zero-voltage soft switching circuit with the auxiliary winding in the full load.
Fig. 3 is an equivalent diagram of each stage of the flyback zero-voltage soft-switching circuit with the auxiliary winding according to the embodiment of the present invention.
Fig. 4 is an experimental waveform diagram of an embodiment of the present invention.
Detailed Description
It should be noted that, in the present application, the embodiments and features of the embodiments may be combined with each other without conflict, and the present invention is further described in detail with reference to the accompanying drawings and specific embodiments.
Referring to fig. 1 to 4, a flyback zero-voltage soft switching circuit with an auxiliary winding according to an embodiment of the present invention includes an excitation inductor Lm and a transformer T R And a switch tube S 1 And a switch tube S 2 Diode D and capacitor C 0 Capacitor C 1 And a resistance R 0 。
Magnetizing inductance Lm and transformer T R Primary side of the switching tube S 1 The source electrode of the power supply is connected with the negative electrode of the power supply; one end of the excitation inductor Lm is connected with the anode of the power supply, and the other end is connected with the switch tube S 1 A drain electrode of (1); transformer T R The secondary side of comprises a transmissionThe output winding and the auxiliary winding; switch tube S 2 Is connected to one end of the output winding, and the drain electrode passes through a capacitor C 1 The other end of the output winding is connected; the anode of the diode D is connected with one end of the auxiliary winding, and the cathode of the diode D passes through the resistor R 0 The other end of the auxiliary winding is connected; capacitor C 0 And a resistance R 0 And (4) connecting in parallel. Preferably, a switching tube S 1 Switch tube S 2 Is an MOS tube.
In one embodiment, the number of turns in the output winding and the auxiliary winding is the same.
The utility model discloses a switch tube S1 switches on with S2 is complementary, has certain blind spot to prevent to switch on altogether attitude between, as shown in fig. 2. The value of the exciting inductance Lm in the circuit is small, so that the current i Lm The ZVS soft switching condition for the main switch S1 can be reversed, as shown by i in FIG. 2 (a) and FIG. 2 (b) Lm Shown in waveform. Since the circuit works slightly differently under light load and full load, the working principle of the circuit under light load will be specifically analyzed, and the working principle under full load will be briefly explained. Considering the junction capacitance of the switch and the dead time, one period can be divided into 7 stages when the circuit is lightly loaded, and the equivalent circuit of each stage is shown in fig. 3. The working principle thereof is described as follows.
1) Stage 1[ t0, t1 ]]In the stage S1, the input voltage and exciting current i are applied to Lm Lm The positive direction increases linearly from a negative value to a positive value. S1 is turned off at time t1, i Lm The maximum value is reached and the phase ends.
2) After the phase 2[ t1, t2] S1 is switched off, the exciting inductor current starts to fall, wherein a part of the exciting inductor current charges the output junction capacitor of the S1, and the drain-source voltage of the S1 linearly rises; and meanwhile, the other part is coupled to the secondary side through a transformer to discharge the output junction capacitance of the S2, the drain-source voltage of the S2 can be approximately considered to be linearly reduced, the drain-source voltage of the S2 is reduced to zero at the moment of t2, and the stage is ended.
3) In the phase 3 2, t3, after the drain-source voltage of S2 drops to zero, the parasitic diode of S2 is turned on, and the drain-source voltage of S2 is clamped in a zero-voltage state, that is, a condition is created for zero-voltage turn-on of S2. While the diode D is also conducting.
4) In phase 4[ t3, t4], the gate at time S2 at t3 becomes high, and S2 is turned on at zero voltage. The exciting inductor Lm bears reverse voltage nVo (n is the turn ratio of the primary side and the secondary side of the transformer), the current on the Lm linearly decreases, t4 decreases to zero at a moment, the current passing through the switching tube S2 and the diode D also decreases to zero at the same time, and the stage is finished.
5) In phase 5[ t4, t5], the diode D is naturally turned off after the current through the diode D falls to zero. And S2 is continuously conducted, the voltage nVo is borne on the Lm, and the current flowing through the Lm is reversely and linearly increased from zero. At time t5, S2 is turned off, and this phase ends.
6) Stage 6[ t5, t6], when the current direction on the exciting inductor Lm is negative, a part of the current discharges the output junction capacitor of S1, so that the drain-source voltage of S1 can be approximately considered as linear reduction; and meanwhile, the other part is coupled to a secondary side through a transformer to charge an output junction capacitor of the S2, so that the drain-source voltage of the S2 rises linearly. the drain-source voltage at time S1 drops to zero at t6, and the phase ends.
7) And in the stage 7[ t6], t7], after the drain-source voltage of the S1 is reduced to zero, the parasitic diode of the S1 is conducted, and the drain-source voltage of the S1 is clamped in a zero-voltage state, so that conditions are created for the zero-voltage conduction of the S1. time t7 is followed by the conduction of S1 at zero voltage condition, and the next cycle is entered. It can be seen that both switches S1 and S2 achieve soft switching.
The above analysis shows that the operating principle of the circuit under light load is slightly different from that under light load, that is, there is no link of natural turn-off when the current of the diode D drops to zero, and the current of the diode D gradually drops to zero after the switching tube S2 is turned off, as shown in fig. 2 (b).
The utility model discloses a parameter design of soft switch is mainly the design of transformer excitation inductance.
The peak-to-peak value of the exciting inductor current can be expressed as
△I Lm =(V in DT)/Lm (1)
In the formula: d is the duty cycle; t is the switching period.
The maximum and minimum values of the excitation inductor current can be expressed as:
I Lmmax =(V in DT)/2Lm+Io/n (2)
I Lmmin =(V in DT)/2Lm-Io/n (3)
in the formula: io is the load current.
From the above principle analysis, it can be seen that the soft switch condition of S1 is created by an | I Lmmin The | is (absolute value) to discharge the output junction capacitor of S1 and simultaneously charge the output junction capacitor of S2 through a transformer; and the soft switch condition of S2 is the result of | I Lmmax The | (absolute value) charges the output junction capacitance of S1, and simultaneously the output junction capacitance of S2 is discharged through the transformer to create.
The soft switching limit condition of S1 and S2 is that the energy stored on Lm charges and discharges the output junction capacitance of S1 and S2 sufficiently to discharge one of the junction capacitances to zero while the other is charged to maximum.
The limiting conditions for S1 are then:
Figure DEST_PATH_IMAGE002
(4)
the limiting conditions of S2 are as follows:
Figure DEST_PATH_IMAGE004
(5)
in the formula: c1 And C2 is the output junction capacitance of S1 and S2 respectively.
Since the dead time is relatively small in an actual circuit, it can be approximately considered that the current on the inductor Lm remains unchanged in the dead time, that is, a constant current source discharges the junction capacitance of the switching tube. The soft switching condition in this case is referred to as a headroom condition.
The allowance condition of S1 is as follows:
Figure DEST_PATH_IMAGE006
Figure DEST_PATH_IMAGE008
(6)
the allowance conditions of S2 are as follows:
Figure DEST_PATH_IMAGE010
Figure DEST_PATH_IMAGE012
(7)
in the formula: tdead1 and tdead2 are dead time periods before S1 and S2 are turned on, respectively.
Since energy is transferred from the power source to the load, i.e. the load current Io>0, to notify the agent I by comparing the formula (2) and the formula (3) Lmmax ︱>︱I Lmmin An |, especially when fully loaded Lmmax ︱>>︱I Lmmin An | is dispensed. The soft switching implementation of S2 is much easier than S1. Therefore, in a specific experimental design, it is critical to design the soft switching condition of S1. Firstly, the maximum dead time which can be borne is determined, and then the excitation inductance Lm is calculated according to the formula (6) and the formula (3). On the premise of realizing soft switching, lm should not be too small so as to avoid causing too large effective value of current on the switch tube and causing too large conduction loss of the switch.
A flyback circuit model with an auxiliary winding and 48V input and 5V/5A output is designed in an example, an experimental result is given, and the correctness of the soft switching implementation method is further verified. The specifications and main parameters of the converter are as follows:
an input voltage Vin 48V;
the output voltage Vo 5V;
outputting current Io 0-5A;
the working frequency f 100kHz;
main switching tubes S1, S2 IRF730, IRFZ44;
an excitation inductance Lm 7OuH;
transformer primary and secondary winding turns ratio 26.
Fig. 4 shows the experimental waveforms for light load (1A) and full load (5A), respectively, and it can be seen from fig. 4 (g) to fig. 4 (j) that the switching tubes S1 and S2 achieve soft switching for both light load and full load.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (2)

1. A flyback zero-voltage soft switching circuit with an auxiliary winding is characterized by comprising an excitation inductor Lm and a transformer T R Switch tube S 1 Switch tube S 2 Diode D and capacitor C 0 Capacitor C 1 And a resistance R 0 Magnetizing inductance Lm and transformer T R Primary side of the switching tube S 1 The source electrode of the power supply is connected with the negative electrode of the power supply; one end of the magnetizing inductor Lm is connected with the anode of the power supply, and the other end is connected with the switching tube S 1 A drain electrode of (1); transformer T R The secondary side of (a) comprises an output winding and an auxiliary winding; switch tube S 2 Is connected to one end of the output winding, and has a drain electrode connected to the output winding via a capacitor C 1 The other end of the output winding is connected; the anode of the diode D is connected with one end of the auxiliary winding, and the cathode of the diode D passes through the resistor R 0 The other end of the auxiliary winding is connected; capacitor C 0 And a resistance R 0 And (4) connecting in parallel.
2. The flyback zero voltage soft switching circuit with an auxiliary winding of claim 1 wherein the number of turns of the output winding and the auxiliary winding are the same.
CN202221735802.3U 2022-07-05 2022-07-05 Flyback zero-voltage soft switching circuit with auxiliary winding Active CN217824740U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202221735802.3U CN217824740U (en) 2022-07-05 2022-07-05 Flyback zero-voltage soft switching circuit with auxiliary winding

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202221735802.3U CN217824740U (en) 2022-07-05 2022-07-05 Flyback zero-voltage soft switching circuit with auxiliary winding

Publications (1)

Publication Number Publication Date
CN217824740U true CN217824740U (en) 2022-11-15

Family

ID=83963574

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202221735802.3U Active CN217824740U (en) 2022-07-05 2022-07-05 Flyback zero-voltage soft switching circuit with auxiliary winding

Country Status (1)

Country Link
CN (1) CN217824740U (en)

Similar Documents

Publication Publication Date Title
CN109217681B (en) Bidirectional resonant converter
CN110224612B (en) Asymmetric half-bridge converter and control method
CN106059313B (en) The circuit of reversed excitation and its control method of active clamp
Canales et al. A zero voltage switching three-level DC/DC converter
US20180248489A1 (en) Converters with hold-up operation
US9252677B2 (en) Quasi resonant push-pull converter and control method thereof
US7957161B2 (en) Power converters
CN112087147B (en) Converter wide gain control method and application thereof
KR20130062916A (en) Two stage resonant converter
US7196913B2 (en) DC conversion apparatus
CN110829838B (en) Zero-voltage soft-switching bidirectional Buck/Boost converter
CN210120487U (en) Clamping circuit and flyback converter
CN103904901A (en) Phase-shift full-bridge converter circuit and control method
CN111262442A (en) Resonance converter based ON ON/OFF control
Chu et al. Analysis and design of a current-fed zero-voltage-switching and zero-current-switching CL-resonant push–pull dc–dc converter
CN110620515A (en) Secondary LLC resonant power conversion circuit
Kim et al. An inductorless asymmetrical ZVS full bridge converter for step-up applications with wide input voltage range
CN115378266A (en) Converter suitable for wide-range output voltage and control method thereof
CN109450256B (en) Quasi-resonance power supply controller
WO2020007108A1 (en) Switching converter
CN217824740U (en) Flyback zero-voltage soft switching circuit with auxiliary winding
CN108964473A (en) A kind of high efficiency high voltage power supply translation circuit
CN112467989B (en) Quasi-single-stage high-power-factor alternating current-direct current converter
CN101447163A (en) Power conversion circuit for plasma display panel
CN213027824U (en) High-voltage wide-input double-tube flyback converter circuit

Legal Events

Date Code Title Description
GR01 Patent grant
GR01 Patent grant