WO2018094918A1 - 一种推挽开关电路及软开关三管推挽正激变换器 - Google Patents

一种推挽开关电路及软开关三管推挽正激变换器 Download PDF

Info

Publication number
WO2018094918A1
WO2018094918A1 PCT/CN2017/076866 CN2017076866W WO2018094918A1 WO 2018094918 A1 WO2018094918 A1 WO 2018094918A1 CN 2017076866 W CN2017076866 W CN 2017076866W WO 2018094918 A1 WO2018094918 A1 WO 2018094918A1
Authority
WO
WIPO (PCT)
Prior art keywords
push
gate
switch
voltage
output
Prior art date
Application number
PCT/CN2017/076866
Other languages
English (en)
French (fr)
Inventor
何伟
Original Assignee
广东百事泰电子商务股份有限公司
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 广东百事泰电子商务股份有限公司 filed Critical 广东百事泰电子商务股份有限公司
Publication of WO2018094918A1 publication Critical patent/WO2018094918A1/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
    • 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
    • H02M3/337—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 in push-pull configuration
    • 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 push-pull forward conversion circuit, in particular to a push-pull switch circuit and a soft-switching three-tube push-pull forward converter.
  • the push-pull circuit is suitable for low-voltage and high-current boosting environments.
  • the existing push-pull circuit is grounded through the switch tube at both ends of the primary winding of the transformer.
  • the center tap of the primary winding of the transformer is loaded with DC voltage, and the two are alternately connected.
  • a switch tube, the two ends of the primary winding of the transformer are alternately grounded, so that the secondary winding of the transformer generates an alternating current higher than the primary side voltage, thereby implementing push-pull conversion.
  • the voltage applied to the center tap of the primary winding of the transformer is fixed, and the voltage of the secondary winding of the transformer is not adjustable, so it is limited by the input side voltage and cannot be applied within a wide input voltage range.
  • the two switching tubes are alternately turned on, and the voltage of the intermediate tap is repeatedly applied to the two switching tubes, the voltage stress of the switching tube is high, thereby affecting the performance and life of the circuit, and in addition, the switching tube switching moment
  • the transformer generates a spike voltage. If a spike absorption circuit is added, the circuit structure is complicated and the circuit cost is increased.
  • the technical problem to be solved by the present invention is that, in view of the deficiencies of the prior art, a push-pull switch circuit and a soft-switching three-tube suitable for various input voltages, capable of reducing voltage stress on the switch tube, and avoiding spikes in the transformer are provided.
  • Push-pull forward converter a push-pull switch circuit and a soft-switching three-tube suitable for various input voltages, capable of reducing voltage stress on the switch tube, and avoiding spikes in the transformer.
  • the present invention adopts the following technical solutions.
  • a push-pull switch circuit includes a first switch tube, a second switch tube, a third switch tube and a transformer, wherein a drain of the first switch tube and a drain of the second switch tube respectively Connected to both ends of the primary winding of the transformer, the source of the first switching transistor and the source of the second switching transistor are grounded, and the gate of the first switching transistor and the gate of the second switching transistor are used for connection Two PWM pulse signals are opposite in phase, the drain of the third switch is used to connect a DC voltage, and the source of the third switch is connected to a middle tap of a primary winding of the transformer, the third switch The gate of the tube is used to connect the PWM pulse signal with adjustable duty cycle, and the output voltage of the secondary winding of the transformer is adjusted by adjusting the duty ratio of the PWM pulse signal of the gate of the third switch.
  • the secondary winding of the transformer is connected with a rectifier bridge, and the secondary side of the transformer is wound by the rectifier bridge
  • the AC voltage outputted by the group is converted into a half-wave DC voltage, and the output of the rectifier bridge is connected with a filter inductor.
  • the first switch tube, the second switch tube and the third switch tube are all N-channel MOS tubes.
  • a pull-down resistor is respectively connected between the gate and the source of the first switching transistor, between the gate and the source of the second switching transistor, and between the gate and the source of the third switching transistor.
  • a current limiting resistor is connected in series to the gate of the first switching transistor, the gate of the second switching transistor, and the gate of the third switching transistor.
  • a soft-switching three-tube push-pull forward converter includes: an input filter circuit, an input end thereof for connecting a DC power source, and the input filter circuit for filtering a voltage outputted by a DC power source to output a DC voltage a push-pull switch circuit, a DC voltage outputted by the input filter circuit is applied to a drain of the third switch tube; an output filter circuit having an input end connected to an output end of the push-pull switch circuit, the output filter The circuit is used to filter the voltage output by the push-pull switch circuit.
  • the input filter circuit comprises two parallel filter capacitors, and the output filter circuit comprises an electrolytic capacitor.
  • an MCU control unit is further included, the gate of the first switch tube, the gate of the second switch tube and the gate of the third switch tube are respectively connected to the MCU control unit, and the MCU control unit is Two PWM pulse signals of opposite phases are output to the gates of the first switching transistor and the gate of the second switching transistor, and a PWM pulse signal with adjustable duty ratio is connected to the gate of the third switching transistor.
  • the method further includes an input voltage sampling circuit connected between the input filter circuit and the MCU control unit, wherein the input voltage sampling circuit is configured to sample the DC voltage outputted by the input filter circuit and transmit the An MCU control unit, the MCU control unit adjusts a duty ratio of a PWM pulse signal applied to a gate of the third switch tube according to a voltage signal input by the input filter circuit, and when the input filter circuit is connected to a voltage lower than a preset When the value is up, the MCU control unit drives the third switch tube to be turned on. When the voltage input by the input filter circuit is higher than a preset value, the MCU control unit occupies the PWM pulse signal of the gate of the third switch tube. The air ratio is lowered.
  • the method further includes an output voltage sampling circuit connected between the output filter circuit and the MCU control unit, wherein the output voltage sampling circuit is configured to sample the voltage outputted by the output filter circuit and transmit the voltage to the MCU. control unit.
  • the output voltage sampling circuit comprises an operational amplifier, the two input ends of the operational amplifier are respectively connected to the output end of the output filter circuit and the ground through a current limiting resistor, and the output end of the operational amplifier is connected to the MCU And a control unit, wherein the MCU control unit further adjusts a duty ratio of the PWM pulse signal loaded on the gate of the third switch tube according to the voltage signal output by the operational amplifier.
  • the DC voltage can pass through the third
  • the switch tube is loaded on the middle tap of the primary winding of the transformer, and the first switch tube and the first switch tube are driven by loading two opposite PWM pulse signals of opposite phases to the gate of the first switch tube and the gate of the second switch tube.
  • the two switching tubes are alternately turned on, so that the secondary winding of the transformer generates an alternating voltage, wherein when the voltage on the input side is low, the third switching tube is kept turned on until the input side is connected to a higher voltage, and is turned down.
  • the duty ratio of the PWM pulse signal of the gate of the third switch tube extends the off time of the primary winding of the transformer to reduce the voltage of the secondary winding of the transformer, and the voltage adjustment is realized by the above process, due to the duty of the PWM pulse signal
  • the ratio of adjustment is wider, which makes the push-pull switch circuit adapt to a variety of input voltages and even the application environment where the input voltage is easy to change, thereby avoiding the application limitation of the input voltage, and at the same time, the third switch tube is repeatedly turned on and off. Extending the time of no voltage on the first switch tube and the second switch tube, so that the voltage stress on the first switch tube and the second switch tube is greatly reduced, which helps High stability and life of the circuit.
  • FIG. 1 is a circuit schematic diagram of a soft-switching three-tube push-pull forward converter of the present invention.
  • Figure 2 is a schematic diagram of the output voltage sampling circuit.
  • FIG. 3 is a schematic diagram of the MCU control unit.
  • the push-pull switch circuit 20 includes a first switch tube Q1, a second switch tube Q2, a third switch tube Q3, and a transformer TS1.
  • the drain of the switching transistor Q1 and the drain of the second switching transistor Q2 are respectively connected to the two ends of the primary winding of the transformer TS1, and the source of the first switching transistor Q1 and the source of the second switching transistor Q2 are grounded.
  • the gate of the first switch transistor Q1 and the gate of the second switch transistor Q2 are used to access two PWM pulse signals of opposite phases, and the drain of the third switch transistor Q3 is used for accessing a DC voltage.
  • the source of the third switching transistor Q3 is connected to the middle tap of the primary winding of the transformer TS1, and the gate of the third switching transistor Q3 is used to connect the PWM pulse signal with adjustable duty cycle, by adjusting the third The duty cycle of the PWM pulse signal at the gate of the switching transistor Q3 adjusts the output voltage of the secondary winding of the transformer TS1.
  • the DC voltage can be applied to the center tap of the primary winding of the transformer TS1 through the third switching transistor Q3, by loading the gate of the first switching transistor Q1 and the gate of the second switching transistor Q2.
  • Two PWM pulse signals of opposite phases are driven to alternately conduct the first switching transistor Q1 and the second switching transistor Q2, so that the secondary winding of the transformer TS1 generates an alternating voltage, wherein when the voltage on the input side is low, the first The three-switch Q3 is kept on until the input side is connected to a higher voltage, the duty ratio of the PWM pulse signal of the gate of the third switch Q3 is lowered, and the turn-off time of the primary winding of the transformer TS1 is extended, so that The voltage of the secondary winding of the transformer TS1 is reduced, which is achieved by the above process.
  • the push-pull switch circuit can adapt to various input voltages and even the application environment where the input voltage is easy to change, thereby avoiding the application limitation of the input voltage.
  • the time of no voltage on the first switching transistor Q1 and the second switching transistor Q2 is prolonged, so that the voltage stress on the first switching transistor Q1 and the second switching transistor Q2 is greatly reduced. It helps to improve the stability and service life of the circuit.
  • the PWM pulse signal applied to the gate of the first switching transistor Q1 and the gate of the second switching transistor Q2 maintains a maximum duty ratio, that is, an instant when the first switching transistor Q1 is turned off, and the second switching transistor Q2 is guided.
  • the primary winding of the transformer TS1 is in an instantaneous short-circuit state, and the instantaneous short-circuit can be used to quickly discharge the current of the secondary side of the transformer TS1, thereby achieving the purpose of soft switching and making the output voltage stable. And reliability is better, greatly improving the voltage conversion effect.
  • the secondary winding of the transformer TS1 is connected with a rectifier bridge (D1, D2, D3, D4), and the alternating current voltage outputted by the secondary winding of the transformer TS1 is converted into a half-wave DC voltage by the rectifier bridge.
  • a filter inductor L3 is connected to an output end of the rectifier bridge.
  • the first switching transistor Q1, the second switching transistor Q2, and the third switching transistor Q3 are all N-channel MOS transistors.
  • a pull-down resistor is respectively connected between the gate and the source of the first switching transistor Q1, the gate and the source of the second switching transistor Q2, and the gate and the source of the third switching transistor Q3.
  • R4, R2, R6 A current limiting resistor (R3, R1, R5) is connected in series to the gate of the first switching transistor Q1, the gate of the second switching transistor Q2, and the gate of the third switching transistor Q3.
  • the present invention also discloses a soft-switching three-tube push-pull forward converter, which is shown in conjunction with FIG. 1 to FIG. 3, and includes:
  • An input filter circuit 10 the input end of which is used for connecting a DC power source, and the input filter circuit 10 is configured to filter a voltage outputted by the DC power source and output a DC voltage;
  • a push-pull switch circuit 20 wherein the DC voltage output from the input filter circuit 10 is applied to the drain of the third switch transistor Q3;
  • An output filter circuit 30 has an input coupled to the output of the push-pull switch circuit 20, and the output filter circuit 30 is configured to filter the voltage output by the push-pull switch circuit 20.
  • the input filter circuit 10 includes two parallel filter capacitors (C7, C8), and the output filter circuit 30 includes an electrolytic capacitor C4.
  • the embodiment further includes an MCU control unit 50.
  • the gate of the first switch Q1, the gate of the second switch Q2, and the gate of the third switch Q3 are respectively connected to the MCU control unit. 50, by The MCU control unit 50 outputs two PWM pulse signals of opposite phases to the gate of the first switching transistor Q1 and the gate of the second switching transistor Q2, and a duty cycle to the gate of the third switching transistor Q3. Adjusted PWM pulse signal.
  • the embodiment further includes an input voltage sampling circuit 60 connected between the input filter circuit 10 and the MCU control unit 50, and the input voltage sampling circuit 60 is configured to filter the input.
  • the DC voltage outputted by the circuit 10 is sampled and transmitted to the MCU control unit 50.
  • the MCU control unit 50 adjusts the duty of the PWM pulse signal applied to the gate of the third switching transistor Q3 according to the voltage signal input to the input filter circuit 10. Ratio, and when the voltage input by the input filter circuit 10 is lower than a preset value, the MCU control unit 50 drives the third switch tube Q3 to be turned on, when the voltage input by the input filter circuit 10 is higher than a preset value.
  • the MCU control unit 50 lowers the duty ratio of the PWM pulse signal of the gate of the third switching transistor Q3.
  • the embodiment further includes an output voltage sampling circuit 40 connected between the output filter circuit 30 and the MCU control unit 50, and the output voltage sampling circuit 40 is configured to filter the output.
  • the voltage output by the circuit 30 is sampled and transmitted to the MCU control unit 50.
  • the output voltage sampling circuit 40 includes an operational amplifier U9B, and two input ends of the operational amplifier U9B are respectively connected to an output end of the output filter circuit 30 and a ground through a current limiting resistor, and the operational amplifier U9B
  • the output terminal is connected to the MCU control unit 50.
  • the MCU control unit 50 also adjusts the duty ratio of the PWM pulse signal applied to the gate of the third switching transistor Q3 according to the voltage signal output by the operational amplifier U9B.
  • the DC power supply voltage is filtered out by C7 and C8 to filter out the ripple voltage.
  • R11 and R12 form an input voltage sampling circuit, and the sampled input voltage is sent to the control chip U1, and U1 determines the working state of Q3.
  • the boost circuit consists of Q1, Q2, Q3, TS1, D1, D2, D3, D4, and L3; when the input voltage is in the low-voltage state, the control chip sets Q3's control PWM3 high, so that Q3 is in through. Q1 and Q2 operate at the maximum duty cycle; when the input voltage reaches the control voltage point after being boosted and boosted, Q3 will operate at the switching frequency of 2 times Q1 or 2 times Q2, and Q1 and Q2 still have the maximum duty. Than working, the control chip controls the duty cycle of PWM3 to regulate the output voltage to achieve output stability.
  • the primary winding of the input transformer TS1 is in a short circuit state for a period of time in the working period, so that the current on the secondary sides D1, D2, D3, and D4 is quickly discharged. Zero current is turned off to achieve the purpose of soft switching.
  • the output filter electrolytic capacitor C4 sends the boosted DC filter to the load.
  • the output sampling circuit is composed of R126, R127, R128, R38, R129, R130, R131, R45, R39, C39, R47, C41, U9, R44, D15, and the sampling circuit feeds back the boosted voltage sample to the control chip U1. To determine the large duty cycle of Q3 small.
  • the push-pull switch circuit and the soft-switching three-tube push-pull forward converter disclosed by the invention have wide input voltage range, simple circuit and convenient control, and the primary MOS tube and the secondary side diode all work in a soft switching state. It has the characteristics of small voltage stress and high circuit efficiency.

Abstract

一种推挽开关电路（20）及软开关三管推挽正激变换器，推挽开关电路包括有第一开关管（Q1）、第二开关管（Q2）、第三开关管（Q3）和变压器（TS1），第一开关管的漏极和第二开关管的漏极分别连接于变压器原边绕组的两端，第一开关管的源极和第二开关管的源极均接地（GND），第一开关管的栅极和第二开关管的栅极用于接入相位相反的两路PWM脉冲信号（Q1_PWM，Q2_PWM），第三开关管的漏极用于接入直流电压，第三开关管的源极连接于变压器原边绕组的中间抽头，第三开关管的栅极用于接入占空比可调的PWM脉冲信号（Q3_PWM），通过调整第三开关管栅极的PWM脉冲信号的占空比而调整变压器副边绕组的输出电压。该推挽开关电路适用于多种输入电压、可降低开关管承受的电压应力、可避免变压器产生尖峰。

Description

一种推挽开关电路及软开关三管推挽正激变换器
技术领域
本发明涉及推挽正激变换电路，尤其涉及一种推挽开关电路及软开关三管推挽正激变换器。
背景技术
推挽电路适合于低电压大电流升压环境，现有的推挽电路是在变压器原边绕组的两端分别通过开关管接地，变压器原边绕组的中间抽头加载直流电压，通过交替接通两个开关管，变压器原边绕组的两端交替接地，使得变压器的副边绕组产生高于原边电压的交流电，进而实现推挽变换。但是上述推挽电路中，变压器原边绕组的中间抽头所加载的电压是固定的，导致变压器副边绕组的电压不可调，因此受到输入侧电压的限制，不能在较宽的输入电压范围内应用，同时，由于两个开关管交替接通，而中间抽头的电压反复加载于两个开关管，使得开关管承受的电压应力较高，进而影响电路的性能和寿命，此外，开关管切换的瞬间，变压器会产生尖峰电压，若增设尖峰吸收电路，不仅使电路结构复杂化，还增加了电路成本。
发明内容
本发明要解决的技术问题在于，针对现有技术的不足，提供一种适用于多种输入电压、可降低开关管承受的电压应力、可避免变压器产生尖峰的推挽开关电路及软开关三管推挽正激变换器。
为解决上述技术问题，本发明采用如下技术方案。
一种推挽开关电路，所述推挽开关电路包括有第一开关管、第二开关管、第三开关管和变压器，所述第一开关管的漏极和第二开关管的漏极分别连接于变压器原边绕组的两端，所述第一开关管的源极和第二开关管的源极均接地，所述第一开关管的栅极和第二开关管的栅极用于接入相位相反的两路PWM脉冲信号，所述第三开关管的漏极用于接入直流电压，所述第三开关管的源极连接于变压器原边绕组的中间抽头，所述第三开关管的栅极用于接入占空比可调的PWM脉冲信号，通过调整所述第三开关管栅极的PWM脉冲信号的占空比而调整变压器副边绕组的输出电压。
优选地，所述变压器的副边绕组连接有整流桥，藉由所述整流桥而将变压器副边绕 组输出的交流电压转换为半波直流电压，所述整流桥的输出端连接有滤波电感。
优选地，所述第一开关管、第二开关管和第三开关管均为N沟道MOS管。
优选地，所述第一开关管的栅极与源极之间、第二开关管的栅极与源极之间以及第三开关管的栅极与源极之间分别连接有一下拉电阻，所述第一开关管的栅极、第二开关管的栅极以及第三开关管的栅极分别串接有一限流电阻。
一种软开关三管推挽正激变换器，其包括有：一输入滤波电路，其输入端用于连接直流电源，所述输入滤波电路用于对直流电源输出的电压进行滤波后输出直流电压；一推挽开关电路，所述输入滤波电路输出的直流电压加载于所述第三开关管的漏极；一输出滤波电路，其输入端连接于推挽开关电路的输出端，所述输出滤波电路用于对推挽开关电路输出的电压进行滤波。
优选地，所述输入滤波电路包括有两个并联的滤波电容，所述输出滤波电路包括有电解电容。
优选地，还包括有一MCU控制单元，所述第一开关管的栅极、第二开关管的栅极和第三开关管的栅极分别连接于MCU控制单元，藉由所述MCU控制单元而向第一开关管的栅极和第二开关管的栅极输出相位相反的两路PWM脉冲信号以及向第三开关管的栅极接入占空比可调的PWM脉冲信号。
优选地，还包括有一输入电压采样电路，所述输入电压采样电路连接于输入滤波电路与MCU控制单元之间，所述输入电压采样电路用于对输入滤波电路输出的直流电压进行采样后传输至MCU控制单元，所述MCU控制单元根据输入滤波电路接入的电压信号而调整加载于第三开关管栅极的PWM脉冲信号的占空比，并且当输入滤波电路接入的电压低于预设值时，所述MCU控制单元驱使第三开关管保持导通，当输入滤波电路接入的电压高于预设值时，所述MCU控制单元将第三开关管栅极的PWM脉冲信号的占空比调低。
优选地，还包括有一输出电压采样电路，所述输出电压采样电路连接于输出滤波电路与MCU控制单元之间，所述输出电压采样电路用于对输出滤波电路输出的电压进行采样后传输至MCU控制单元。
优选地，所述输出电压采样电路包括有运放，所述运放的两个输入端分别通过限流电阻而连接于输出滤波电路的输出端和地，所述运放的输出端连接于MCU控制单元，所述MCU控制单元还根据运放输出的电压信号而调整加载于第三开关管栅极的PWM脉冲信号的占空比。
本发明公开的推挽开关电路及软开关三管推挽正激变换器中，直流电压可通过第三 开关管而加载于变压器原边绕组的中间抽头，通过向所述第一开关管的栅极和第二开关管的栅极加载相位相反的两路PWM脉冲信号，以驱动第一开关管和第二开关管交替导通，使得变压器的副边绕组产生交流电压，其中，当输入侧的电压较低时，令第三开关管保持导通，直至输入侧接入较高的电压时，调低第三开关管栅极的PWM脉冲信号的占空比，延长变压器原边绕组的关断时间，以令变压器副边绕组的电压降低，通过上述过程实现了电压调节，由于PWM脉冲信号的占空比调节范围较广，使得该推挽开关电路能适应多种输入电压乃至输入电压容易发生变化的应用环境，进而避免了受输入电压的应用限制，同时，第三开关管反复通断的过程中，延长了第一开关管和第二开关管上无电压的时间，使得第一开关管和第二开关管承受的电压应力大大减小，有助于提高电路的稳定性和使用寿命。
附图说明
图1为本发明软开关三管推挽正激变换器的电路原理图。
图2为输出电压采样电路的原理图。
图3为MCU控制单元的原理图。
具体实施方式
下面结合附图和实施例对本发明作更加详细的描述。
本发明公开了一种推挽开关电路，如图1所示，所述推挽开关电路20包括有第一开关管Q1、第二开关管Q2、第三开关管Q3和变压器TS1，所述第一开关管Q1的漏极和第二开关管Q2的漏极分别连接于变压器TS1原边绕组的两端，所述第一开关管Q1的源极和第二开关管Q2的源极均接地，所述第一开关管Q1的栅极和第二开关管Q2的栅极用于接入相位相反的两路PWM脉冲信号，所述第三开关管Q3的漏极用于接入直流电压，所述第三开关管Q3的源极连接于变压器TS1原边绕组的中间抽头，所述第三开关管Q3的栅极用于接入占空比可调的PWM脉冲信号，通过调整所述第三开关管Q3栅极的PWM脉冲信号的占空比而调整变压器TS1副边绕组的输出电压。
上述推挽开关电路中，直流电压可通过第三开关管Q3而加载于变压器TS1原边绕组的中间抽头，通过向所述第一开关管Q1的栅极和第二开关管Q2的栅极加载相位相反的两路PWM脉冲信号，以驱动第一开关管Q1和第二开关管Q2交替导通，使得变压器TS1的副边绕组产生交流电压，其中，当输入侧的电压较低时，令第三开关管Q3保持导通，直至输入侧接入较高的电压时，调低第三开关管Q3栅极的PWM脉冲信号的占空比，延长变压器TS1原边绕组的关断时间，以令变压器TS1副边绕组的电压降低，通过上述过程实现了 电压调节，由于PWM脉冲信号的占空比调节范围较广，使得该推挽开关电路能适应多种输入电压乃至输入电压容易发生变化的应用环境，进而避免了受输入电压的应用限制，同时，第三开关管Q3反复通断的过程中，延长了第一开关管Q1和第二开关管Q2上无电压的时间，使得第一开关管Q1和第二开关管Q2承受的电压应力大大减小，有助于提高电路的稳定性和使用寿命。
作为一种优选方式，加载于第一开关管Q1栅极和第二开关管Q2栅极的PWM脉冲信号保持最大占空比，即第一开关管Q1关断的瞬间，第二开关管Q2导通，然而在该切换的瞬间，变压器TS1的原边绕组处于瞬时短路状态，利用该瞬时短路，可使得变压器TS1副边的电流快速泄放，从而实现软开关的目的，使得输出电压的稳定性和可靠性更好，大大提高了电压转换效果。
本实施例中，所述变压器TS1的副边绕组连接有整流桥(D1、D2、D3、D4)，藉由所述整流桥而将变压器TS1副边绕组输出的交流电压转换为半波直流电压。进一步地，所述整流桥的输出端连接有滤波电感L3。
关于器件选型，所述第一开关管Q1、第二开关管Q2和第三开关管Q3均为N沟道MOS管。其中，所述第一开关管Q1的栅极与源极之间、第二开关管Q2的栅极与源极之间以及第三开关管Q3的栅极与源极之间分别连接有一下拉电阻(R4、R2、R6)。所述第一开关管Q1的栅极、第二开关管Q2的栅极以及第三开关管Q3的栅极分别串接有一限流电阻(R3、R1、R5)。
在此基础上，本发明还公开了一种软开关三管推挽正激变换器，结合图1至图3所示，其包括有：
一输入滤波电路10，其输入端用于连接直流电源，所述输入滤波电路10用于对直流电源输出的电压进行滤波后输出直流电压；
一推挽开关电路20，其中，输入滤波电路10输出的直流电压加载于所述第三开关管Q3的漏极；
一输出滤波电路30，其输入端连接于推挽开关电路20的输出端，所述输出滤波电路30用于对推挽开关电路20输出的电压进行滤波。
关于输入输出的滤波部分，所述输入滤波电路10包括有两个并联的滤波电容(C7、C8)，所述输出滤波电路30包括有电解电容C4。
为了实现自动控制，本实施例还包括有一MCU控制单元50，所述第一开关管Q1的栅极、第二开关管Q2的栅极和第三开关管Q3的栅极分别连接于MCU控制单元50，藉由 所述MCU控制单元50而向第一开关管Q1的栅极和第二开关管Q2的栅极输出相位相反的两路PWM脉冲信号以及向第三开关管Q3的栅极接入占空比可调的PWM脉冲信号。
为了反馈输入电压，本实施例还包括有一输入电压采样电路60，所述输入电压采样电路60连接于输入滤波电路10与MCU控制单元50之间，所述输入电压采样电路60用于对输入滤波电路10输出的直流电压进行采样后传输至MCU控制单元50，所述MCU控制单元50根据输入滤波电路10接入的电压信号而调整加载于第三开关管Q3栅极的PWM脉冲信号的占空比，并且当输入滤波电路10接入的电压低于预设值时，所述MCU控制单元50驱使第三开关管Q3保持导通，当输入滤波电路10接入的电压高于预设值时，所述MCU控制单元50将第三开关管Q3栅极的PWM脉冲信号的占空比调低。
为了反馈输出电压，本实施例还包括有一输出电压采样电路40，所述输出电压采样电路40连接于输出滤波电路30与MCU控制单元50之间，所述输出电压采样电路40用于对输出滤波电路30输出的电压进行采样后传输至MCU控制单元50。进一步地，所述输出电压采样电路40包括有运放U9B，所述运放U9B的两个输入端分别通过限流电阻而连接于输出滤波电路30的输出端和地，所述运放U9B的输出端连接于MCU控制单元50，所述MCU控制单元50还根据运放U9B输出的电压信号而调整加载于第三开关管Q3栅极的PWM脉冲信号的占空比。
将上述各单元整合后构成本发明的优选实施例，结合图1至图3所示，该实施例整体的工作原理为：
输入滤波电路中，DC电源电压通过C7、C8滤除纹波电压后输出。R11、R12组成输入电压采样电路，将采样到的输入电压送给控制芯片U1，由U1来决定Q3的工作状态。
推挽开关电路中，升压电路由Q1、Q2、Q3、TS1、D1、D2、D3、D4、L3组成；当输入电压在低压状态控制芯片将Q3的控制PWM3一直置高，让Q3处于直通，Q1与Q2以最大占空比工作；当输入电压经变压升压后达到控制电压点时，Q3将以2倍Q1或2倍Q2的开关频率工作，并且Q1与Q2仍然以最大占空比工作，控制芯片控制PWM3的占空比来调节输出电压，以达到输出稳定。同时由于Q1与Q2的占空比最大，在工作周期内有一段时间内输入变压器TS1的原边绕组是在短路状态，导致副边D1、D2、D3、D4上的电流很快放完从而达到零电流关断，达到软开关的目的。
输出滤波电路中，输出滤波电解电容C4将升压后的直流滤波送给负载。输出采样电路由R126、R127、R128、R38、R129、R130、R131、R45、R39、C39、R47、C41、U9、R44、D15组成，采样电路将升压后的电压采样反馈给控制芯片U1，来确定Q3的占空比大 小。
本发明公开的推挽开关电路及软开关三管推挽正激变换器，其输入电压的范围较宽，且电路简单、控制方便，原边MOS管与副边二极管均工作在软开关状态，具有电压应力小、电路效率高等特点。
以上所述只是本发明较佳的实施例，并不用于限制本发明，凡在本发明的技术范围内所做的修改、等同替换或者改进等，均应包含在本发明所保护的范围内。

Claims (10)

  1. 一种推挽开关电路，其特征在于，所述推挽开关电路包括有第一开关管、第二开关管、第三开关管和变压器，所述第一开关管的漏极和第二开关管的漏极分别连接于变压器原边绕组的两端，所述第一开关管的源极和第二开关管的源极均接地，所述第一开关管的栅极和第二开关管的栅极用于接入相位相反的两路PWM脉冲信号，所述第三开关管的漏极用于接入直流电压，所述第三开关管的源极连接于变压器原边绕组的中间抽头，所述第三开关管的栅极用于接入占空比可调的PWM脉冲信号，通过调整所述第三开关管栅极的PWM脉冲信号的占空比而调整变压器副边绕组的输出电压。
  2. 如权利要求1所述的推挽开关电路，其特征在于，所述变压器的副边绕组连接有整流桥，所述整流桥的输出端连接有滤波电感。
  3. 如权利要求1所述的推挽开关电路，其特征在于，所述第一开关管、第二开关管和第三开关管均为N沟道MOS管。
  4. 如权利要求1所述的推挽开关电路，其特征在于，所述第一开关管的栅极与源极之间、第二开关管的栅极与源极之间以及第三开关管的栅极与源极之间分别连接有一下拉电阻，所述第一开关管的栅极、第二开关管的栅极以及第三开关管的栅极分别串接有一限流电阻。
  5. 一种软开关三管推挽正激变换器，其特征在于，包括有：
    一输入滤波电路，其输入端用于连接直流电源，所述输入滤波电路用于对直流电源输出的电压进行滤波后输出直流电压；
    如权利要求1-4任一项所述的推挽开关电路，所述输入滤波电路输出的直流电压加载于所述第三开关管的漏极；
    一输出滤波电路，其输入端连接于推挽开关电路的输出端，所述输出滤波电路用于对推挽开关电路输出的电压进行滤波。
  6. 如权利要求5所述的软开关三管推挽正激变换器，其特征在于，所述输入滤波电路包括有两个并联的滤波电容，所述输出滤波电路包括有电解电容。
  7. 如权利要求5所述的软开关三管推挽正激变换器，其特征在于，还包括有一MCU控制单元，所述第一开关管的栅极、第二开关管的栅极和第三开关管的栅极分别连接于MCU控制单元，藉由所述MCU控制单元而向第一开关管的栅极和第二开关管的栅极输出相位相反的两路PWM脉冲信号以及向第三开关管的栅极接入占空比可调的PWM脉冲信号。
  8. 如权利要求7所述的软开关三管推挽正激变换器，其特征在于，还包括有一输入电压采样电路，所述输入电压采样电路连接于输入滤波电路与MCU控制单元之间，所述输入电压采样电路用于对输入滤波电路输出的直流电压进行采样后传输至MCU控制单元，所述 MCU控制单元根据输入滤波电路接入的电压信号而调整加载于第三开关管栅极的PWM脉冲信号的占空比，并且当输入滤波电路接入的电压低于预设值时，所述MCU控制单元驱使第三开关管保持导通，当输入滤波电路接入的电压高于预设值时，所述MCU控制单元将第三开关管栅极的PWM脉冲信号的占空比调低。
  9. 如权利要求7所述的软开关三管推挽正激变换器，其特征在于，还包括有一输出电压采样电路，所述输出电压采样电路连接于输出滤波电路与MCU控制单元之间，所述输出电压采样电路用于对输出滤波电路输出的电压进行采样后传输至MCU控制单元。
  10. 如权利要求9所述的软开关三管推挽正激变换器，其特征在于，所述输出电压采样电路包括有运放，所述运放的两个输入端分别通过限流电阻而连接于输出滤波电路的输出端和地，所述运放的输出端连接于MCU控制单元，所述MCU控制单元还根据运放输出的电压信号而调整加载于第三开关管栅极的PWM脉冲信号的占空比。
PCT/CN2017/076866 2016-11-25 2017-03-16 一种推挽开关电路及软开关三管推挽正激变换器 WO2018094918A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201611061749.2 2016-11-25
CN201611061749.2A CN106787774B (zh) 2016-11-25 2016-11-25 一种推挽开关电路及软开关三管推挽正激变换器

Publications (1)

Publication Number Publication Date
WO2018094918A1 true WO2018094918A1 (zh) 2018-05-31

Family

ID=58911091

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2017/076866 WO2018094918A1 (zh) 2016-11-25 2017-03-16 一种推挽开关电路及软开关三管推挽正激变换器

Country Status (2)

Country Link
CN (1) CN106787774B (zh)
WO (1) WO2018094918A1 (zh)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108880273A (zh) * 2018-09-19 2018-11-23 重庆线易电子科技有限责任公司 推挽式电力转换器控制电路
CN109217682A (zh) * 2018-09-19 2019-01-15 重庆线易电子科技有限责任公司 推挽式电力转换器
CN109640494A (zh) * 2019-01-26 2019-04-16 东莞市擎洲光电科技有限公司 一种过载保护及短路可恢复pwm调光器
CN110380620A (zh) * 2019-06-17 2019-10-25 嘉善中正新能源科技有限公司 一种用于大功率车载双向dc的逆变电路
CN113315384A (zh) * 2021-06-16 2021-08-27 中南大学 一种互补有源钳位软开关推挽变换器及其调制方法
CN114498589A (zh) * 2020-11-13 2022-05-13 圣邦微电子（北京）股份有限公司 一种输出级限流电路
CN114498589B (zh) * 2020-11-13 2024-05-10 圣邦微电子（北京）股份有限公司 一种输出级限流电路

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108712083A (zh) * 2018-05-28 2018-10-26 钟曙 一种三开关推挽输入高频链单级逆变电路

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100214810A1 (en) * 2009-02-23 2010-08-26 Funai Electric Co., Ltd. Push-Pull Inverter
CN102684502A (zh) * 2012-05-10 2012-09-19 合肥同智机电控制技术股份有限公司 直流升压变换装置
CN203056977U (zh) * 2012-12-18 2013-07-10 中科恒源科技股份有限公司 一种升压隔离型dc-dc变换器
CN105048850A (zh) * 2015-07-02 2015-11-11 南京航空航天大学 一种单级zvs型推挽式高频环节dc/ac变换器

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4391496B2 (ja) * 2006-05-16 2009-12-24 菊水電子工業株式会社 Ｄｃ−ｄｃコンバータ
CN101615043A (zh) * 2009-07-17 2009-12-30 广州金升阳科技有限公司 一种推挽电路稳压输出的方法及其电源变换器

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100214810A1 (en) * 2009-02-23 2010-08-26 Funai Electric Co., Ltd. Push-Pull Inverter
CN102684502A (zh) * 2012-05-10 2012-09-19 合肥同智机电控制技术股份有限公司 直流升压变换装置
CN203056977U (zh) * 2012-12-18 2013-07-10 中科恒源科技股份有限公司 一种升压隔离型dc-dc变换器
CN105048850A (zh) * 2015-07-02 2015-11-11 南京航空航天大学 一种单级zvs型推挽式高频环节dc/ac变换器

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108880273A (zh) * 2018-09-19 2018-11-23 重庆线易电子科技有限责任公司 推挽式电力转换器控制电路
CN109217682A (zh) * 2018-09-19 2019-01-15 重庆线易电子科技有限责任公司 推挽式电力转换器
CN108880273B (zh) * 2018-09-19 2023-11-28 重庆线易电子科技有限责任公司 推挽式电力转换器控制电路
CN109217682B (zh) * 2018-09-19 2023-11-28 重庆线易电子科技有限责任公司 推挽式电力转换器
CN109640494A (zh) * 2019-01-26 2019-04-16 东莞市擎洲光电科技有限公司 一种过载保护及短路可恢复pwm调光器
CN110380620A (zh) * 2019-06-17 2019-10-25 嘉善中正新能源科技有限公司 一种用于大功率车载双向dc的逆变电路
CN110380620B (zh) * 2019-06-17 2024-03-19 嘉善中正新能源科技有限公司 一种用于大功率车载双向dc的逆变电路
CN114498589A (zh) * 2020-11-13 2022-05-13 圣邦微电子（北京）股份有限公司 一种输出级限流电路
CN114498589B (zh) * 2020-11-13 2024-05-10 圣邦微电子（北京）股份有限公司 一种输出级限流电路
CN113315384A (zh) * 2021-06-16 2021-08-27 中南大学 一种互补有源钳位软开关推挽变换器及其调制方法

Also Published As

Publication number Publication date
CN106787774A (zh) 2017-05-31
CN106787774B (zh) 2023-06-16

Similar Documents

Publication Publication Date Title
WO2018094918A1 (zh) 一种推挽开关电路及软开关三管推挽正激变换器
US10498225B2 (en) Dual-rectification full bridge interleaved single stage PFC converter circuit and control methods thereof
US10637363B2 (en) Converters with hold-up operation
US7499299B2 (en) Method and apparatus for reducing body diode conduction of synchronous rectifiers
KR100547289B1 (ko) 간헐 모드로 동작하는 동기 정류형 직렬 공진 컨버터
US5590032A (en) Self-synchronized drive circuit for a synchronous rectifier in a clamped-mode power converter
WO2018107619A1 (zh) 基于pfc与llc谐振的智能全桥正弦波电压转换电路
US9479048B2 (en) Resonant isolated active power factor correction (PFC) rectifier
WO2021051858A1 (zh) 一种有源钳位反激变换器的控制方法
CN108964474B (zh) 一种基于llc谐振变换器的三模态整流拓扑结构
US20080002444A1 (en) High-efficiency power converter system
TWI813687B (zh) 圖騰柱型單相功因修正轉接器
US6819574B2 (en) Self-driven circuit for synchronous rectifier DC/DC converter
WO2020253026A1 (zh) 电流采样电路、电流过零检测电路、图腾柱无桥pfc电路及控制方法
US11757367B2 (en) Flyback switch circuit and control method thereof
CN102480221A (zh) 一种PFC控制器在Buck电路中的应用方法
CN106059294B (zh) 一种开关电源及变换方法
CN107395037B (zh) 一种输出电压可调的高功率因数桥式同步整流电路
US20060083029A1 (en) Switching power supply
US7548442B2 (en) Power converter with coupled inductor
CN102931848B (zh) 一种应用于液晶显示产品高效率的反激式电源系统
WO2020143275A1 (zh) 一种改进型反激变换器
WO2020007108A1 (zh) 一种开关变换器
JP2002199719A (ja) 複合共振型スイッチング電源装置
TWI760788B (zh) 具有半橋電路的轉換器

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: 17875003

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: 17875003

Country of ref document: EP

Kind code of ref document: A1