CN101174795B - Semi-bridge resonant vibration converter - Google Patents

Abstract

A half-bridge resonance converter includes a primary winding, a secondary winding provided with a first endpoint, a second endpoint and a central endpoint, a first electronic switch, a second electronic switch, a first energy storage assembly, a second energy storage assembly and a load end provided with a first endpoint and a second endpoint. The first endpoint of the secondary winding thereof is in tandem connection with the first electronic switch and the first energy storage assembly, the second endpoint is in tandem connection with the second electronic switch and the second energy storage assembly, the first endpoint of the load end is in connection with the first and the second energy storage assemblies at the same time, and the second endpoint is in connection with the central endpoint of the secondary winding.

Description

Semi-bridge resonant vibration converter

Technical field

The present invention is relevant a kind of electric pressure converter, refers to a kind of synchronous halfwave rectifier transducer that reaches Zero voltage transition and low electric energy loss especially.

Background technology

The semibridge system transducer is for using two power switchs and doing the transducer that forward power is changed traditionally, applicable to smaller transformer, and high-efficiency power conversion charger pursues one's goal for its exploitation, with LLC resonant circuit cpable of lowering power switch cost, promote power supply conversion efficiency and reduce energy loss, be present line related industry institute development product.

Traditional transducer is the assembly of secondary side circuit electronic switch with the diode, because diode can produce a considerable electric energy loss, make the conversion efficiency of transducer to promote, therefore improve the electronic switch of secondary side circuit, avoid a large amount of electric energy losses to become the technological development target of transducer.

Summary of the invention

The object of the present invention is to provide an electric pressure converter, utilize with transistor to replace diode to form the electronic switch of secondary side, to reduce the electric energy loss of voltage transitions.

Reach the object of the invention, a kind of semi-bridge resonant vibration converter of the present invention is characterized in that, comprises:

First side winding;

Secondary side winding has first and second end points and a central end points;

One first electronic switch has first and second end points, and aforementioned first end points is connected with first end points of aforementioned secondary side winding;

One second electronic switch has first and second end points, and aforementioned first end points is connected with second end points of aforementioned secondary side winding;

One first energy storage component has first and second end points, and aforementioned first end points is connected with second end points of aforementioned first electronic switch;

One second energy storage component has first and second end points, and aforementioned first end points is connected with second end points of aforementioned second electronic switch; And

One load end has first and second end points, and aforementioned first end points is connected with second end points of aforementioned first energy storage component and second end points of second energy storage component simultaneously, and aforementioned second end points is connected with the central end points of aforementioned secondary side winding.

It is oppositely that the start of wherein aforementioned first electronic switch and aforementioned second electronic switch is closed, and causes first end points or second end points and the aforementioned load end conducting of aforementioned secondary side winding.

Wherein aforementioned first electronic switch comprises a MOSFET power transistor and a cross-over connection in the grid (G) of aforementioned MOSFET power transistor and the tertiary winding of source electrode (S), and first end points of first electronic switch is the source electrode (S) for the MOSFET power transistor, and second end points is the drain electrode (D) for the MOSFET power transistor.

Wherein aforementioned second electronic switch comprises a MOSFET power transistor and a cross-over connection in the grid (G) of aforementioned MOSFET power transistor and the tertiary winding of source electrode (S), and first end points of second electronic switch is the source electrode (S) for the MOSFET power transistor, and second end points is the drain electrode (D) for the MOSFET power transistor.

The tertiary winding of wherein aforementioned first electronic switch is the identical winding with same number of turns with the tertiary winding of aforementioned second electronic switch.

The combination that wherein aforementioned first energy storage component is connected with a resistance by an inductance diode in parallel, aforementioned inductance can be released via the combination that aforementioned diodes is connected with resistance can, and first end points of first energy storage component is the positive terminal for aforementioned diodes, and second end points of first energy storage component is the end points that combines with aforementioned inductance for aforementioned resistance.

The combination that wherein aforementioned second energy storage component is connected with a resistance by an inductance diode in parallel, aforementioned inductance can be released via the combination that aforementioned diodes is connected with resistance can, and first end points of second energy storage component is the positive terminal for aforementioned diodes, and second end points of second energy storage component is the end points that combines with aforementioned inductance for aforementioned resistance.

Can avoid the electronic switch energy loss excessive by energy storage component is set, therefore can make semi-bridge resonant vibration converter of the present invention reach the purpose of minimum energy loss because of reverse bias causes.

Description of drawings

Aforementioned purpose of the present invention or feature will be described in detail according to accompanying accompanying drawing, and what only need understand is that accompanying accompanying drawing and the cited case are as explanation but not in restriction or shrinkage limit the present invention, wherein:

Fig. 1 is the circuit diagram of semi-bridge resonant vibration converter of the present invention;

Fig. 2 is the circuit diagram of known semi-bridge resonant vibration converter;

Fig. 3 is the current waveform figure of known semi-bridge resonant vibration converter;

Fig. 4 is the current lead-through path profile of known semi-bridge resonant vibration converter in module 1;

Fig. 5 is the current lead-through path profile of known semi-bridge resonant vibration converter in module 2;

Fig. 6 is the current lead-through path profile of known semi-bridge resonant vibration converter in module 3;

Fig. 7 is semi-bridge resonant vibration converter of the present invention and known semi-bridge resonant vibration converter assembly conducting oscillogram;

Fig. 8 is for using the loss current oscillogram of Schottky diode as electronic switch diode D+ and D-;

Fig. 9 is for using the loss current oscillogram of MOSFET power diode as electronic switch diode D+ and D-;

Figure 10 is the loss current oscillogram of semi-bridge resonant vibration converter of the present invention.

Embodiment

Though the present invention will consult the appended icon that contains preferred embodiment of the present invention and fully describe, should be appreciated that the personage who is familiar with one's own profession skill can revise creation described herein, obtains the effect of this creation simultaneously before described here.Therefore, need to understand following description to the personage that is familiar with the one's own profession technology and Yan Weiyi discloses widely, and its content does not lie in and limits this creation.

Be the circuit diagram of semi-bridge resonant vibration converter of the present invention with reference to figure 1, this circuit comprises: first side winding; Secondary side winding N2 has first and second end points and a central end points; One first electronic switch has first and second end points, and aforementioned first end points is connected with first end points of aforementioned secondary side winding; One second electronic switch has first and second end points, and aforementioned first end points is connected with second end points of aforementioned secondary side winding; One first energy storage component has first and second end points, and aforementioned first end points is connected with second end points of aforementioned first electronic switch; One second energy storage component has first and second end points, and aforementioned first end points is connected with second end points of aforementioned second electronic switch; And a load end, having first and second end points, aforementioned first end points is connected with second end points of aforementioned first energy storage component and second end points of second energy storage component simultaneously, and aforementioned second end points is connected with the central end points of aforementioned secondary side winding.

Wherein, first electronic switch of secondary side winding is a MOSFET power transistor Q ₊With a winding N ₃Combination, and second electronic switch is to be a MOSFET power transistor Q _-With a winding N ₃Combination, reaching the purpose of synchronous rectification, and the start of this first electronic switch and this second electronic switch to close be oppositely, cause first end points or second end points and the load end conducting of this secondary side winding, reaching the purpose of halfwave rectifier, and the winding N of first electronic switch ₃Winding N with second electronic switch ₃Be for having the identical winding of same number of turns.

Be connected a filter inductance L respectively at this first electronic switch and second electronic switch ₊, L _-, so that the electric current from the output of first electronic switch and second electronic switch is carried out rectification, and in order to overcome the output voltage V at load end ₀And the pressure drop between the first end-point voltage V ' of secondary side winding is at filter inductance L ₊A diode D in parallel ₊With resistance R ₊Tandem compound forming first energy storage component, and at filter inductance L _-A diode D in parallel _-With resistance R _-Tandem compound to form second energy storage component, in order to filter inductance L to be provided ₊, L _-Release can the path.

The present invention is electric energy loss and a conversion efficiency of improving a traditional semibridge system transducer, is the circuit framework figure of a traditional semibridge system transducer with reference to figure 2, and this transducer comprises one lateral circuits and secondary side circuit, wherein a V _dBe input voltage, V ₀Then be the voltage to be measured of output, first side winding N ₁With secondary side winding N ₂The number of turns than for N=N ₁/ N ₂

With reference to figure 3 is the oscillogram of this semibridge system converter operation, because its positive half period and negative half-cycle are the operating mode of symmetry, therefore this semibridge system transducer can be divided into following work pattern with positive half period:

Module 1:(t ₀-t ₁)

At the state of module 1, transistor Q _HAnd Q _LNeither conducting makes resonance inductor L _rAnd magnetizing inductance L _mInitial current be I ₀, resonant capacitor C _rInitial voltage be V ₀, because I ₀Less than 0, so its current lead-through waveform as shown in Figure 4, because magnetizing inductance L _mCross-pressure be fixed as nV ₀, so this magnetizing inductance L _mCan be considered a stable DC voltage source, and this resonance current IL _rWith the resonance capacitor C _rTherefore electric current can get for equal:

$\left\{\begin{array}{c}{L}_r\frac{{\mathrm{di}}_{L_r}\left(t\right)}{\mathrm{dt}}+v_{C_r}\left(t\right)=\frac{V_d}{2}-n{V}_o\\ i_{\mathrm{Lr}}\left(t_0\right)=I_0\\ V_c\left(t_0\right)={\mathrm{<figure-callout\; id="0"\; label="V"\; filenames="H2006101379044E00031.png"\; state="\{\{state\}\}">V</figure-callout>}}_0\end{array}\right\}$

And can further try to achieve resonance inductor L _rAnd resonant capacitor C _rElectric current and voltage equation:

$\left\{\begin{array}{c}{i}_{L_r}\left(t\right)=\left\{{\mathrm{<figure-callout\; id="0"\; label="I"\; filenames="H2006101379044E00031.png"\; state="\{\{state\}\}">I</figure-callout>}}_0\cos \right[{\mathrm{\&omega;}}_{r1}(t-t_0)]+\frac{\frac{V_d}{2}-n{V}_o-V_0}{Z_{01}}\sin [{\mathrm{\&omega;}}_{r1}(t-t_0)\left]\right\}u(t-t_0)\\ v_{C_r}\left(t\right)=\{\frac{V_d}{2}-n{V}_o-(\frac{V_d}{2}-n{V}_o-V_0)\cos [{\mathrm{\&omega;}}_{r1}(t-t_0)]+I_0{Z}_{01}\sin [{\mathrm{\&omega;}}_{r1}(t-t_0)\left]\right\}u(t-t_0)\end{array}\right.$

And can get Fig. 3 time t according to this equation ₀To t ₁Resonance inductor L _rAnd resonant capacitor C _rElectric current and voltage oscillogram.

Wherein, because of this magnetizing inductance L _mCan be considered a stable DC voltage source, so the resonance inductor L of primary side _rWith the resonance capacitor C _rCan be considered resonance, its resonance frequency is:

${\mathrm{\&omega;}}_{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="H2006101379044E00011.png,H2006101379044E00021.png"\; state="\{\{state\}\}">r</figure-callout>}1}=\frac{1}{\sqrt{\mathrm{LrCr}}}$

And must a characteristic impedance Z ₀₁For:

$Z_{01}=\sqrt{\frac{\mathrm{Lr}}{\mathrm{Cr}}}$

And magnetizing inductance L _mThe current equation formula and can derive as follows:

$\left\{\begin{array}{c}{L}_m\frac{{\mathrm{di}}_{L_m}\left(t\right)}{\mathrm{dt}}=n{V}_o\\ i_{L_m}\left(t_0\right)={\mathrm{<figure-callout\; id="0"\; label="I"\; filenames="H2006101379044E00031.png"\; state="\{\{state\}\}">I</figure-callout>}}_0\end{array}\right.\&DoubleRightArrow;i_{L_m}\left(t\right)=i_{L_m}\left(t_0\right)+{\&Integral;}_{t_0}^t\frac{n{V}_o}{L_m}\mathrm{d\&tau;}=I_0+\frac{n{V}_o}{L_m}(t-t_0)$

And this magnetizing inductance L _mThe slope of electric current can be expressed as:

$\mathrm{Slope}\left(I_{\mathrm{Lm}}\right)=\frac{n\&CenterDot;\mathrm{Vo}}{\mathrm{Lm}}$

Can get Fig. 3 time t according to this equation ₀To t ₁Magnetizing inductance L _mCurrent waveform figure.

As resonance current I _LrGreater than 0, this resonance current I _LrThe sense of current reverse, so diode D _HBe terminated, and the mode of operation of this semibridge system transducer enters pattern 2.

Module 2:(t ₁-t ₂)

At the state of module 2, because resonance current I _LrOppositely, so transistor Q _HConducting, its current lead-through waveform as shown in Figure 5, and module 1 is identical, this magnetizing inductance L _mCan be considered a stable DC voltage source, and this resonance current I _LrWith the resonance capacitor C _rTherefore electric current can get for equal:

$\left\{\begin{array}{c}{L}_r\frac{{\mathrm{di}}_{L_r}\left(t\right)}{\mathrm{dt}}+v_{C_r}\left(t\right)=\frac{V_d}{2}-n{V}_o\\ i_{\mathrm{Lr}}\left(t_1\right)=0\\ V_c\left(t_1\right)={\mathrm{<figure-callout\; id="1"\; label="V"\; filenames="H2006101379044E00011.png,H2006101379044E00021.png"\; state="\{\{state\}\}">V</figure-callout>}}_1\end{array}\right\}$

And can further try to achieve resonance inductor L _rAnd resonant capacitor C _rElectric current and voltage equation:

$\left\{\begin{array}{c}{i}_{L_r}\left(t\right)=\frac{\frac{V_d}{2}-n{V}_o-V_0}{Z_{01}}\sin \left[{\mathrm{\&omega;}}_{r1}(t-t_1)\right]u(t-t_1)\\ v_{C_r}\left(t\right)=\{\frac{V_d}{2}-n{V}_o-(\frac{V_d}{2}-n{V}_o-V_1)\cos [{\mathrm{\&omega;}}_{r1}(t-t_1)\left]\right\}u(t-t_1)\end{array}\right.$

And can get time t among Fig. 3 according to this equation ₁To t ₂Resonance inductor L _rAnd resonant capacitor C _rElectric current and voltage oscillogram.

And its resonance frequency and characteristic impedance are all identical with module 1:

${\mathrm{\&omega;}}_{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="H2006101379044E00011.png,H2006101379044E00021.png"\; state="\{\{state\}\}">r</figure-callout>}1}=\frac{1}{\sqrt{\mathrm{LrCr}}},$ $Z_{01}=\sqrt{\frac{\mathrm{Lr}}{\mathrm{Cr}}}$

And magnetizing inductance L _mThe current equation formula and can derive as follows:

$\left\{\begin{array}{c}{L}_m\frac{{\mathrm{di}}_{L_m}\left(t\right)}{\mathrm{dt}}=n{V}_o\\ i_{L_m}\left(t_0\right)=I_1\end{array}\right.\&DoubleRightArrow;i_{L_m}\left(t\right)=+i_{L_m}\left(t_1\right)+{\&Integral;}_{t_0}^t\frac{n{V}_o}{L_m}\mathrm{d\&tau;}=I_1+\frac{n{V}_o}{L_m}(t-t_1)$

And this magnetizing inductance L _mThe slope of electric current can be expressed as:

$\mathrm{Slope}\left(I_{\mathrm{Lm}}\right)=\frac{n\&CenterDot;\mathrm{Vo}}{\mathrm{Lm}}$

Can get Fig. 3 time t according to this equation ₁To t ₂Magnetizing inductance L _mCurrent waveform figure.

Because the transistor polarity of secondary side circuit, make the electric current I of secondary side ₂Must not be reverse, so relative primary side current I ₁Must not be less than 0, therefore as resonance current I _LrWith magnetizing current I _LmWhen equating, this semibridge system transducer promptly enters module 3.

Module 3:(t ₂-t ₃)

At the state of module 3, because resonance current I _LrWith magnetizing current I _LmEquate, at this moment primary side current I ₁Be 0, its current waveform figure as shown in Figure 6, resonance inductor L _rWith magnetizing inductance L _mThe series connection and with resonance capacitor C _rResonance, and can get a current relation formula:

$\left\{\begin{array}{c}(L_r+L_m)\frac{{\mathrm{di}}_{L_r}\left(t\right)}{\mathrm{dt}}+v_{C_r}\left(t\right)=\frac{V_d}{2}\\ i_{\mathrm{Lr}}\left(t_2\right)=I_2\\ V_c\left(t_2\right)=V_2\end{array}\right\}$

And can further try to achieve resonance inductor L _rAnd resonant capacitor C _rElectric current and voltage equation:

$\left\{\begin{array}{c}{i}_{L_r}\left(t\right)=\left\{I_2\cos \right[{\mathrm{\&omega;}}_{r2}(t-t_2)]+\frac{\frac{V_d}{2}-V_2}{Z_{02}}\sin [{\mathrm{\&omega;}}_{r2}(t-t_2)\left]\right\}u(t-t_2)\\ v_{C_r}\left(t\right)=\{\frac{V_d}{2}-(\frac{V_d}{2}-V_2)\cos [{\mathrm{\&omega;}}_{r2}(t-t_2)]+I_2{Z}_{02}\sin [{\mathrm{\&omega;}}_{r2}(t-t_2)\left]\right\}u(t-t_2)\end{array}\right.$

And can get Fig. 3 time t according to this equation ₀To t ₁Resonance inductor L _rAnd resonant capacitor C _rElectric current and voltage oscillogram.

Wherein, because resonance inductor L _rWith magnetizing inductance L _mThe series connection and with resonance capacitor C _rTherefore resonance can get a resonance frequency:

${\mathrm{\&omega;}}_{r2}=\frac{1}{\sqrt{(\mathrm{Lr}+\mathrm{Lm})\mathrm{Cr}}}$

And must a characteristic impedance Z ₀₂For:

$Z_{02}=\sqrt{\frac{\mathrm{Lr}+\mathrm{Lm}}{\mathrm{Cr}}}$

And magnetizing inductance L _mThe current equation formula and can derive as follows:

$i_{L_m}\left(t\right)=i_{\mathrm{Lr}}\left(t\right)$

Can get Fig. 3 time t according to this equation ₂To t ₃Magnetizing inductance L _mCurrent waveform figure, and get primary side current I ₁Be 0, and because secondary side current I ₂With primary side current I ₁Be to be direct ratio, therefore can get:

$I_2=\frac{N_1}{N_2}{I}_1=0$

Therefore as can be known, in module 3, resonance inductor L _rWith magnetizing inductance L _mElectric current all equal, and its slope is little than module 1 with module 2:

$\mathrm{Slope}\left(I_{\mathrm{Lm}}\right)=\frac{n\&CenterDot;\mathrm{Vo}}{L_c+\mathrm{Lm}}$

As primary side transistor Q _HClose, module 3 promptly finishes.

Be semi-bridge resonant vibration converter of the present invention and known semi-bridge resonant vibration converter assembly conducting situation with reference to figure 7, at the circuit of the secondary side winding of known semi-bridge resonant vibration converter, owing to diode D ₊And D _-Therefore being electronic switch, producing a considerable electric energy loss, is example with the electric current of 16A, with reference to figure 8 for using Schottky diode as electronic switch diode D ₊And D _-The loss current oscillogram, if wherein traditional Schottky diode, because of its forward pressure drop be about 0.5V, so its power loss is about:

P _d＝V _F×I _O＝0.5×16＝8W

If use low pressure drop type Schottky diode, because of its forward pressure drop be about 0.3V, so its power loss is about:

P _d＝V _F×I _O＝0.3×16＝4.8W

And with MOSFET field-effect transistor Q ₊And Q _-Replace diode D ₊And D _-Can significantly reduce its electric energy loss, be to use the MOSFET power diode as electronic switch diode D with reference to figure 9 ₊And D _-The loss current oscillogram, wherein the forward pressure drop of MOSFET power transistor conducting is about 0.07V, pressure drop during Body Diode conducting is about 0.6V, and MOSFET power transistor ON time is about 2 times of Body Diode ON time, so its power loss is about:

$P_d=V_F\&times;I_O=0.07\&times;16\&times;\frac{2}{3}+0.6\&times;16\&times;\frac{1}{3}=3.9W$

But become the problem that electronic switch will face a reverse bias owing to utilize the MOSFET field-effect transistor to replace diode, under the state of module 3, secondary side current I ₂Be 0, and V ' and V _oHave a pressure reduction, it is partially contrary to make that this MOSFET field-effect transistor may cause, and this reverse bias can cause the BodyDiode conducting, causes electric energy loss significantly to be risen, so the present invention utilizes filter inductance L in back series connection one energy storage component of electronic switch ₊And L _-Eliminate V ' and V _oBetween existing pressure reduction:

$\frac{{\mathrm{di}}_2\left(t\right)}{\mathrm{dt}}=\frac{V_o-V^{\&prime;}}{L_{+}}$

Utilize the resistance diode of connecting, D in this energy storage component ₊Series connection R ₊And D _-Series connection R _-, to form filter inductance L ₊And L _-Release can the path, when module 3 finishes, filter inductance L ₊And L _-Just according to D ₊Series connection R ₊And D _-Series connection R _-Release and can the path electric energy stored in this inductance be discharged, therefore semi-bridge resonant vibration converter of the present invention just can overcome the problem that reverse bias causes Body Diode conducting, with reference to the loss current oscillogram of Figure 10 for semi-bridge resonant vibration converter of the present invention, wherein the forward pressure drop of MOSFET power transistor conducting is about 0.07V, so its power loss is about:

P _d＝V _F×I _O＝0.07×16＝1.12W

Therefore by the numeric ratio of above power loss more as can be known, semi-bridge resonant vibration converter of the present invention can reach the purpose of lowest power loss.

After describing preferred embodiment of the present invention in detail, being familiar with this technology personage can clearly understand, carry out various variations and change under following claim and the spirit not breaking away from, and the present invention also is not subject to the execution mode of illustrated embodiment in the specification.

Claims (4)

1. a semi-bridge resonant vibration converter is characterized in that, comprises:

First side winding;

Secondary side winding has first and second end points and a central end points;

One first electronic switch has first and second end points, and first end points of aforementioned first electronic switch is connected with first end points of aforementioned secondary side winding;

One second electronic switch has first and second end points, and first end points of aforementioned second electronic switch is connected with second end points of aforementioned secondary side winding;

One first energy storage component, the combination of connecting with a resistance by an inductance diode in parallel, energy is released in the combination that aforementioned inductance is connected with resistance via aforementioned diodes, and an end of the inductance of the positive terminal of the diode of first energy storage component and first energy storage component is connected with second end points of aforementioned first electronic switch;

One second energy storage component, the combination of connecting with a resistance by an inductance diode in parallel, the combination that the inductance of aforementioned second energy storage component is connected with the resistance of second energy storage component via the diode of aforementioned second energy storage component release can, and an end of the inductance of the positive terminal of the diode of second energy storage component and second energy storage component is connected with second end points of aforementioned second electronic switch; And

One load end, has first and second end points, first end points of aforementioned load end is connected with the end points of the other end combination of the inductance of aforementioned second energy storage component with the end points of the other end combination of the inductance of aforementioned first energy storage component and the resistance of second energy storage component with the resistance of aforementioned first energy storage component simultaneously, and second end points of aforementioned load end is connected with the central end points of aforementioned secondary side winding.

2. semi-bridge resonant vibration converter as claimed in claim 1, it is characterized in that, the action relationships of wherein aforementioned first electronic switch and aforementioned second electronic switch is oppositely, causes the first end points conducting of first end points or second end points and the aforementioned load end of aforementioned secondary side winding.

3. semi-bridge resonant vibration converter as claimed in claim 1, it is characterized in that, wherein aforementioned first electronic switch comprises a MOSFET power transistor and a cross-over connection in the grid (G) of aforementioned MOSFET power transistor and the tertiary winding of source electrode (S), and first end points of first electronic switch is the source electrode (S) for the MOSFET power transistor, and second end points be drain electrode (D) for the MOSFET power transistor, and aforementioned second electronic switch comprises a MOSFET power transistor and a cross-over connection in the grid (G) of aforementioned MOSFET power transistor and the tertiary winding of source electrode (S), and first end points of second electronic switch is the source electrode (S) for the MOSFET power transistor, and second end points is the drain electrode (D) for the MOSFET power transistor.

4. semi-bridge resonant vibration converter as claimed in claim 3 is characterized in that, the tertiary winding of the tertiary winding of wherein aforementioned first electronic switch and aforementioned second electronic switch is the winding with same number of turns.

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