CN102158095B - Full-bridge power inverter with series-input and series-output and control method thereof - Google Patents

Abstract

The invention relates to a full-bridge power inverter with series-input and series-output, wherein the full-bridge power inverter comprises two modules adopting the same structure and parameters. The first module comprises a first input filtration capacitor connected with the input end of the first module in parallel, and a first output filtration capacitor connected with the output end of the first module in parallel, and the second module comprises a second input filtration capacitor connected with the input end of the second module in parallel, and a second output filtration capacitor connected with the output end of the second module in parallel. A phase shift control circuit is used for outputting a same PWM (pulse width modulation) driving signal shared by power switching tubes of the two modules. The invention simultaneously provides the control method for the full-bridge power inverter with the series-input and the series-output. The full-bridge power inverter with the series-input and the series-output and the control method have the following advantages: the power inversion topology with high-voltage input and high-voltage output is realized, and the full-bridge power inverter and the control method are applicable to occasions with the high-voltage input and the high-voltage output; furthermore, the circuit is simple in structure, the complexity of a control system and the cost of a whole machine are reduced, and the reliability of the system is improved.

Description

Full-bridge power converter and the control method thereof of series connection input series connection output

Technical field

The present invention relates to power inverter and control method thereof, particularly a kind of full-bridge power converter and control method thereof of the input series connection output of connecting.

Background technology

Carry out the high pressure input as the DC converting of three-phase alternating current 380V, through power factor correction, voltage output tends to reach 700-800V.Under coal mine, the line voltage grade exists interchange 660V or 1140V, can reach very person 2000V of 1000V behind over commutation.At with these voltage levels as the input power supply the DC-to-DC power inverter, if take single phase-shifting full-bridge power inverter, then the withstand voltage of power switch pipe can reach more than the 2000V.Device for power switching cost height not only, and limited the switching frequency raising.In order to select for use the lower power switch pipe of withstand voltage to solve the problem that high pressure is imported DC converting, mainly adopt these 3 kinds of schemes of input tandem plan of three level DC power inverter technical scheme, the direct serial connection technology scheme of power switch pipe and power inverter at present.The 3rd class scheme must solve all pressures problem of serial module structure input voltage, and common method is that each module has independently controller, and increases special Pressure and Control ring for this controller, and this has just increased the complexity of control system.

Summary of the invention

The objective of the invention is to overcome above-mentioned defective, a kind of power conversion topologies device that goes for high voltage input, high voltage output occasion is provided, reduce complexity and the complete machine cost of control system, improve full-bridge power converter and the control method thereof of the series connection input series connection output of system reliability.

For achieving the above object, the full-bridge power converter of a kind of input series connection output of connecting provided by the invention, comprise full-bridge power converter and phase-shift control circuit thereof, described full-bridge power converter comprises first module and second module with same structure and parameter, and first phase-shift control circuit that shares of module and second module, wherein first module comprises first input filter capacitor that is parallel to its input and first output filter capacitor that is parallel to its output, second module comprises second input filter capacitor that is parallel to its input and second output filter capacitor that is parallel to its output, the input of first module and second module is connected mutually, the output of first module and second module is series connection mutually also, be that input voltage is added on first input filter capacitor and second input filter capacitor of mutual series connection, and output voltage is added on first output filter capacitor and second output filter capacitor of mutual series connection; Phase-shift control circuit output has PWM to drive signal, and the power switch pipe of first module and second module shares identical PWM and drives signal.

The full-bridge power converter of single-phase series input series connection output of the present invention, wherein said first module and second module are the zero-voltage zero-current full-bridge power converter that has pulsactor.

The present invention connects and imports the full-bridge power converter of series connection output, and wherein said first module and first module, second module are the zero-voltage and zero-current switch full-bridge power converter.

The present invention connects and imports the full-bridge power converter of series connection output, wherein said phase-shift control circuit comprises sample circuit, the phase shift Drive and Control Circuit, amplifying circuit and 4 driving transformers, wherein sample circuit comprises and is connected in two sample resistances of full-bridge power converter output, sampled signal exports the phase shift Drive and Control Circuit to by the tie point of two sample resistances, 4 drive control signal of phase shift Drive and Control Circuit output are connected to 4 inputs of amplifying circuit respectively, first output of amplifying circuit and second output are connected to the input of first driving transformer and second driving transformer respectively, the 3rd output of amplifying circuit and the 4th output are connected to the input of the 3rd driving transformer and the moving transformer of 4 wheel driven respectively, the output of the output of first driving transformer and the 3rd driving transformer is connected to the first modular power control end of switching tube respectively, and the output of the moving transformer of the output of second driving transformer and 4 wheel driven is connected to the second modular power control end of switching tube respectively.

The present invention connects and imports the full-bridge power converter of series connection output, and it is the chip formation of UC3875 that wherein said phase shift Drive and Control Circuit adopts model.

For achieving the above object, the control method of the full-bridge power converter of a kind of input series connection output of connecting provided by the invention, wherein the full-bridge power converter setting has first module and second module of same structure and parameter, and described first module and the shared phase-shift control circuit of second module, described phase-shift control circuit arranges sample circuit, phase shift Drive and Control Circuit, amplifying circuit and 4 driving transformers, and this control method comprises;

1) input of described first module and second module is connected mutually, the output of described first module and second module is series connection mutually also, described phase-shift control circuit output has PWM to drive signal, and the power switch pipe of described first module and second module shares this identical PWM and drives signal;

2) sampled signal that will be obtained by two sample resistances of full-bridge power converter output exports described phase shift Drive and Control Circuit to, 4 drive control signal of described phase shift Drive and Control Circuit output are connected to 4 inputs of described amplifying circuit respectively, first output of described amplifying circuit and second output are connected to the input of first driving transformer and second driving transformer respectively, the 3rd output of described amplifying circuit and the 4th output are connected to the input of the 3rd driving transformer and the moving transformer of 4 wheel driven respectively, the output of the output of described first driving transformer and the 3rd driving transformer is connected to the described first modular power control end of switching tube respectively, and the output of the moving transformer of the output of described second driving transformer and 4 wheel driven is connected to the described second modular power control end of switching tube respectively.

The connect full-bridge power converter of input series connection output and advantage and the good effect of control method thereof of the present invention is: owing to adopted the full-bridge power converter of series connection input series connection output, be provided with the cover phase-shift control circuit that two full-bridge power converters share, the identical pwm signal of this control circuit output two-way drives the power switch pipe of two full-bridge power converter correspondences, two-way drives the signal electrical isolation, thereby realized a kind of power conversion topologies that solves the output of high pressure input high pressure, be applicable to the high voltage input, high voltage output occasion, and circuit is simple in structure, reduce complexity and the complete machine cost of control system, improved the reliability of system.

Be elaborated with reference to accompanying drawing below in conjunction with embodiment.

Description of drawings

Fig. 1 is the connect block diagram of full-bridge power converter of input series connection output of the present invention;

Fig. 2 is the circuit structure diagram that has the zero-voltage zero-current full-bridge power converter of pulsactor;

Fig. 3 is the circuit structure diagram of Zero-voltage switch full-bridge power inverter;

Fig. 4 is the connect equivalent circuit diagram of full-bridge power converter topological structure of input series connection output of the present invention;

Fig. 5 is the connect circuit theory diagrams of full-bridge power converter embodiment of input series connection output of the present invention;

Fig. 6 is the circuit theory diagrams of phase-shift control circuit;

Fig. 7 is the circuit theory diagrams of amplifying circuit;

Fig. 8 is the circuit theory diagrams of driving transformer.

Embodiment

With reference to Fig. 1, the present invention connects and imports the full-bridge power converter of series connection output, comprises full-bridge power converter and phase-shift control circuit thereof.Full-bridge power converter comprises first module and second module with same structure, manufactures and designs according to identical parameters.Wherein first module comprises the first input filter capacitor C1 that is parallel to its input and the first output filter capacitor Co1 that is parallel to its output, and second module comprises the second input filter capacitor C2 that is parallel to its input and the second output filter capacitor Co2 that is parallel to its output.The input of first module and second module is connected mutually, the output of first module and second module is series connection mutually also, be that input voltage is added on the first input filter capacitor C1 and the second input filter capacitor C2 of mutual series connection, and output voltage is added on the first output filter capacitor Co1 and the second output filter capacitor Co2 of mutual series connection.Phase-shift control circuit output has PWM to drive signal, and the power switch pipe of first module and second module shares identical PWM and drives signal.Topological structure, the phase shifting control strategy of employing such as the accompanying drawing 4 of this input series connection, output series connection.

In the present invention connects the specific embodiment of full-bridge power converter of input series connection output, full-bridge power converter by two zero-voltage zero-current full-bridge power converter inputs connect mutually, output also is composed in series mutually, realizes that with a slice UC3875 control chip phase shifting control output duty cycle signal gives two full-bridge power converter modules.

With reference to Fig. 2 and Fig. 3, the basic functional principle of full-bridge power converter adopts prior art, be summarized as follows: when the conducting simultaneously of two master power switch pipes of converter brachium pontis diagonally opposing corner, the input power supply transfers the energy to output, meanwhile former limit blocking capacitor Cb is charged by primary current, to another direction linear change, pulsactor is in saturation condition to voltage Vcb from a direction on it.Former limit is in afterflow during the stage after leading arm switch tubulose attitude transfer process is finished, and the voltage on the blocking capacitor is approximate to keep constant, and polarity is identical with primary current, becomes a reverse blocking voltage source just, makes primary current quickly fall to zero.Primary current will be attempted to changing inversely after dropping to zero, but at this moment pulsactor has withdrawed from saturatedly, presents very big perception, has stoped further flowing of electric current, makes electric current remain on zero.In the whole operating state of converter, utilize the parasitic capacitance of power switch pipe and the leakage inductance resonance of transformer, thereby make power switch pipe realize conducting and the zero-current switching of no-voltage.

Although two modules share duty cycle signals D, there is its distinctive duty-cycle loss phenomenon in the full-bridge power converter of phase shifting control.Duty-cycle loss is because have resonant inductance in the converter, primary current from just (bear) negative to changing to (just) to the time, because primary current is not enough to provide load current, the equal conducting of marginal rectifying tube, load is in the afterflow state, thereby secondary voltage has just been lost this a part of square-wave voltage, that is to say that transformer secondary duty ratio can be littler than the former limit of transformer duty ratio.The duty ratio of transformer secondary is effective duty ratio, be subjected to the former limit of transformer leakage inductance, input voltage, output current, etc. the not quite identical influence of parameter, effective duty ratio Deff1 of first module and effective duty ratio Deff2 of second module are also inequality.Therefore for the input voltage vin 1 of two modules and Vin2 and output voltage U o1 and Uo2 following formula is arranged:

U _o1＝V _in1ND _eff1 (1)

U _o2＝V _in2ND _eff2 (2)

Wherein N is Ns/Np, and Ns is transformer secondary umber of turn, and Np is the former limit of transformer umber of turn, and two transformers have identical turn ratio N.Two modules have identical output current Io.If Ploss1 and Ploss2 are respectively the loss power of two modules, this loss comprises the loss power of devices such as switching tube, output rectifier diode, transformer, inductance, and loss power and power output have certain relation, are defined as:

P _loss1＝λ _1(Uo1Io)U _o1I _o (3)

P _loss2＝λ _2(Uo2Io)U _o2I _o (4)

λ wherein _{1 (Uo1Io)}And λ _{2 (Uo2Io)}Be expressed as the loss factor of two modules under the power output of correspondence respectively.For convenience, with λ _{1 (Uo1Io)}Be expressed as λ ₁, λ _{2 (Uo2Io)}Be expressed as λ ₂Do not have linear character between the loss power of general power inverter and the power output, so λ ₁And λ ₂Be not a fixed numeric values, but along with power output changes and the coefficient of variation.With reference to Fig. 5 and Fig. 6, according to the power equal principle power output and loss power equivalence are arrived the former limit of transformer, and represent with current source, if input average voltage U _InStable, and V _In1And V _In2Stablize, then the average current I of capacitor C 1 and capacitor C 2 _Cl=I _C2=O, two module series connection, total input current of two modules is I _In, therefore have:

I _in＝(1+λ ₁)ND _eff1I _o＝(1+λ ₂)ND _eff2I _o (5)

The input gross power of two modules is power output and loss power sum, V _In1And V _In2When stablizing, the efficiency eta of two modules ₁And η ₂Be expressed as:

$\frac{{\mathrm{\η}}_1}{{\mathrm{\η}}_2}=\frac{\frac{U_{o1}{I}_o}{U_{o1}{I}_o+{\mathrm{\λ}}_1{U}_{o1}{I}_o}}{\frac{U_{o2}{I}_o}{U_{o2}{I}_o+{\mathrm{\λ}}_2{U}_{o2}\mathrm{Io}}}=\frac{1+{\mathrm{\λ}}_2}{1+{\mathrm{\λ}}_1}---\left(6\right)$

According to document, if with saturated inductance L in the circuit among Fig. 5 _S1And L _S2Regard desirable pulsactor as, consider that duty ratio loses scholar's problem, effective duty ratio of two full-bridge power converters is seen expression formula (7), (8).Infer this converter accordingly under the certain situation of other conditions, the voltage input is more high, and effective duty ratio of its correspondence is more big.

${\mathrm{<figure-callout\; id="1"\; label="D\; eff"\; filenames="HDA0000063251490000031.png,HDA0000063251490000041.png"\; state="\{\{state\}\}">D</figure-callout>}}_{\mathrm{eff}}=D-\frac{{\mathrm{NL}}_{k1}(I_o-\mathrm{\&Delta;}{I}_{\mathrm{lf}1})}{T_s(V_{\mathrm{in}1}+V_{\mathrm{cbp}1})}---\left(7\right)$

$D_{\mathrm{eff}2}=D-\frac{{\mathrm{NL}}_{k2}(I_o-\mathrm{\&Delta;}{I}_{\mathrm{lf}2})}{T_s(V_{\mathrm{in}2}+V_{\mathrm{cbp}2})}---\left(8\right)$

V _Cbpj(j=1,2) are respectively the capacitance C of two modules _B1And C _B2On crest voltage, when generally designing, at fully loaded capacitance crest voltage V down _CbpBe about 0.2 times of specified input voltage, formula (9) is its expression formula.

$V_{\mathrm{cbpj}}=\frac{{\mathrm{NI}}_o{\mathrm{DT}}_s}{2C_{\mathrm{bj}}}---\left(9\right)$

For two modules, j gets 1 and 2 respectively.Because two module series connection also share a duty cycle signals D, and two module parameter unanimities, then have according to formula (9):

V _cbp1＝V _cbp2＝V _cbp (10)

During general design, the outputting inductance value is bigger, and the electric current consecutive hours can be thought Δ _Ilf1And Δ _Ilf2With respect to I _oCan ignore, and two module parameters equate L _K1=L _K2=L _k, T _sBe switch periods.Then during the module initialization, V _In1And V _In2Be U _In/ 2, can judge that according to formula (7), (8) two modules have identical effective duty ratio D _EffSuppose that the loss factor of first module this moment is less than the loss factor of second module, i.e. λ ₁＜λ ₂, η ₁＞η ₂There is this moment formula (11) to set up.

(1+λ ₁)ND _effI _o＜(1+λ ₂)ND _effI _o (11)

If always import average voltage U _InConstant, two modules have identical overall average input current I _In, capacitor C ₁Charging, capacitor C ₂Discharge.Be subjected to this to influence V _In1V can be raise _In2Reduce.Can obtain D according to formula (7), (8) _Eff1Raise D _Eff2Descend.If there is V _In1Be elevated to U ₁And V _In2Be reduced to U ₂The time satisfy formula (12), (13), then capacitor C ₁Discharge, and capacitor C ₂Charging.V _In2Raise V _In1Can reduce, thereby with V _In1Be stabilized in (U _In/ 2, U ₁) interval, V _In2Be stabilized in (U ₂, U _In/ 2) if interval is U ₁And U ₂Be positioned at ± 10%U _In/ 2 intervals then just have using value on engineering.

(1+λ ₁)ND _eff1I _o＞(1+λ ₂)ND _eff2I _o(12)

Formula (7) substitution (12) and abbreviation are obtained:

Will $\frac{D_{\mathrm{eff}1}}{D_{\mathrm{eff}2}}>\frac{{\mathrm{\&eta;}}_1}{{\mathrm{\&eta;}}_2}---\left(13\right)$

Can obtain formula (13) analysis: η ₁/ η ₂More close to 1, formula (13) is easy being met more, thereby with V _In2And V _In1The interval that limits is more little.If two module η under any power output ₁=η ₂, V _In1And V _In2Will maintain U _In/ 2.Be further quantitative analysis, wushu (7), (8) substitution (13).Have:

$\frac{(D-\frac{{\mathrm{NL}}_k{I}_o}{T_s(V_{\mathrm{in}1}+V_{\mathrm{cbp}})})}{(D-\frac{{\mathrm{NL}}_k{I}_o}{T_s(V_{\mathrm{in}2}+V_{\mathrm{cbp}})})}>\frac{{\mathrm{\&eta;}}_1}{{\mathrm{\&eta;}}_2}---\left(\text{14}\right)$

Because module has its intrinsic efficiency curve.So under specific two module situations, V _In1And V _In2Residing interval is all relevant with parameters such as transformer leakage inductance, output current, the transformer turn ratio, switching frequency, duty ratios.But as long as two designed modules have identical efficient in certain input voltage interval.Then formula (14) just can be set up.Therefore, this scheme just can be limited in U with the input voltage of two full-bridge power converters _In/ 2.

As the above analysis, this scheme has utilized the duty-cycle loss of full-bridge power converter to realize the equilibrium of input voltage cleverly.Because the high module of input voltage has bigger effective duty ratio, therefore when the low module of voltage stops to secondary transmission energy, the module that input voltage is high also will be transmitted energy to secondary, cause that capacitance voltage descends, when in certain input voltage range, effectively satisfy formula (14) between duty ratio and the efficient, then this scheme can be limited in the input voltage of two modules in this scope.Thereby do not need independent Pressure and Control.Only need when design module, to consider that will design the identical efficient of trying one's best in this interval gets final product.

In the present invention connects the specific embodiment of full-bridge power converter of input series connection output, first module and second module can be the zero-voltage zero-current full-bridge power converter that has pulsactor, as shown in Figure 2, the input voltage parameter is: direct current (DC) 800V (± 20%), output voltage: DC1000V, output-current rating 10A, as follows for its parameter of each unit module: switching frequency 26K, the former secondary turn ratio of transformer Np: Ns:16: 29, output inductor Lf:500uH, former limit blocking capacitor C _b: 6.6uF, former limit transformer leakage inductance: 1.5uH, former limit filter capacitor: 4100uF output filter capacitor: 300uF.IGBT model: IKW40N120T2.

Wherein the power switch pipe Q11 of first module and Q12 form leading-bridge, Q13 and Q14 form lagging leg, the power switch pipe Q21 of second module and Q22 form leading-bridge, Q23 and Q24 form lagging leg, Cb1 and Cb2 are former limit blocking capacitor, Lk1 and Lk2 are the former limit leakage inductance of transformer, and Ls1 and Ls2 are the pulsactor on former limit.Inductance L f1 and capacitor C o1 and inductance L f2 and capacitor C o2 form the output filter circuit of first module and second module respectively.Ro is load resistance.T1 and T2 are respectively the isolating transformer of first module and second module.DR1-DR4 and DR5-DR8 form the rectifier bridge of two modules.Wherein Q11 and Q21, Q12 and Q22, Q13 and Q23, the driving signal of Q14 and Q24 is identical.By the output of same phase-shift control circuit and after isolating, be divided into two-way and drive the power switch pipe that signal reaches two full-bridge power converter correspondences.It is that benchmark carries out phase shift to lagging leg driving signal with leading arm that PWM drives signal.If this moment, two full-bridge converter direct-flow input end voltages were respectively Vin1 and Vin2, then this moment, corresponding output voltage size was controlled by duty ratio D, and duty ratio D depends on that lagging leg drives the phase shifting angle θ of signal and leading arm signal.

In the present invention connected other embodiment of full-bridge power converter of input series connection output, first module and second module are also replaceable to be the Zero-voltage switch full-bridge power inverter, as shown in Figure 3.

The following describes the operation principle of phase-shift control circuit.

The connect phase-shift control circuit of full-bridge power converter of input series connection output of the present invention comprises sample circuit, phase shift Drive and Control Circuit, amplifying circuit and driving transformer.

With reference to Fig. 5, sample circuit comprises and is connected in two sample resistance R10, R20 of full-bridge power converter output, and sampled signal Vuo exports the phase shift Drive and Control Circuit to by the tie point of two sample resistance R10, R20.

The phase shift Drive and Control Circuit adopts UC3875 chip U1 to constitute.With reference to Fig. 6, resistance R 4 and resistance R 5 are the Dead Time controlling resistance among the figure, by regulating the Dead Time that the leading arm of its resistance size adjustment and lagging leg drive signal, prevent the leading arm of first module or second module and leading directly to of two switching tubes of lagging leg.The 2nd, 3,4 pin of chip U1 are respectively output, inverting input, the in-phase input end of its inner integrated operational amplifier.Resistance R 3 one ends connect in-phase input end, and an other end is the voltage given input.Resistance R 1, capacitor C 1, resistance R 2, capacitor C 2 and operational amplifier proportion of composing integral control.Output end voltage is connected to resistance R 1 an other end through behind the electric resistance partial pressure.Realize the FEEDBACK CONTROL of output voltage like this, guaranteed output voltage tracing preset voltage signal.

The 17th, 18 pins of chip U1 are respectively the drive control signal of switching tube and following switching tube correspondence above the leading arm, and the 12nd, 13 pins are the driving signal of switching tube and following switching tube correspondence above the lagging leg.

The full-bridge power converter of input series connection output relates to the two-way full-bridge because the present invention connects, and having 8 switching tubes needs to drive, and therefore must isolate and amplify.

With reference to Fig. 7, in the amplifying circuit, V1, V3, V5 and V7 are NPN type triode, and V2, V4, V6 and V8 are the positive-negative-positive triode.D1-D8 is fly-wheel diode.

The output OUTA of chip U1 phase-shifted control signal is connected to two control utmost points of V1, V2, the output OUTB of chip U1 phase-shifted control signal is connected to two control utmost points of V3, V4, the output OUTC of chip U1 phase-shifted control signal is connected to two control utmost points of V5, V6, and the output OUTD of chip U1 phase-shifted control signal is connected to two control utmost points of V7, V8.The series connection node of fly-wheel diode is output, and 4 output signals are connected to driving transformer, is respectively A, B, C, D.

With reference to Fig. 8,4 driving transformers are respectively T1, T2, T3 and T4.Rfpa output signal A, B are connected to the input of driving transformer T1 and T2 respectively, and rfpa output signal C, D are connected to the input of driving transformer T3 and T4 respectively.

Driving transformer T1 and T2 drive two switching tube Q11, Q12 and Q21, the Q22 of the leading arm of first module or second module respectively.Driving transformer T3 and T4 drive two switching tube Q13, Q14 and Q23, the Q24 of the lagging leg of first module or second module respectively.A2+ and A2-are connected gate pole and the emitter of the switching tube Q11 of full-bridge circuit respectively.A1+ and A1-are connected gate pole and the emitter of the switching tube Q21 of full-bridge circuit respectively.B2-and B2+ are connected gate pole and the emitter of the switching tube Q12 of full-bridge circuit respectively.B1-and B1+ are connected gate pole and the emitter of the switching tube Q22 of full-bridge circuit respectively.C2+ and C2-are connected gate pole and the emitter of the switching tube Q13 of full-bridge circuit respectively.C1+ and C1-are connected gate pole and the emitter of the switching tube Q23 of full-bridge circuit respectively.D2-and D2+ are connected gate pole and the emitter of the switching tube Q14 of full-bridge circuit respectively.D1-and D1+ are connected gate pole and the emitter of the switching tube Q24 of full-bridge circuit respectively.

The course of work of phase-shift control circuit is: when the 18 pin OUTA of chip U1 output high level, the 17th pin OUTB output low level, the 13rd pin OUTC output low level, during the 12nd pin OUTD output high level, V1 and V4 conducting, V5 and V8 conducting, driving transformer accept to drive signal, and A is high level, and B is low level, C is low level, D is high level, driving transformer T1, the end A2+ of the same name of T2, A1+, B2+ and B1+ output high level, A2-, A1-, B2-and B1-output low level, driving transformer T3, the end C2+ of the same name of T4, C1+, D2+ and D1+ output low level, C2-, C1-, D2-and D1-output high level.Q11 and Q21 switching tube accept to drive signal conduction like this, and it is negative level that Q12 and Q22 drive signal, is in cut-off state; Q14 and Q24 switching tube accept to drive signal conduction, and it is negative level that Q13 and Q23 drive signal, is in cut-off state.

With the 18th pin OUTA output low level that should chip U1, the 17th pin OUTB exports high level, the 13rd pin OUTC exports high level, during the 12nd pin OUTD output low level, V2 and V3 conducting, V6 and V7 conducting, driving transformer accept to drive signal, and A is low level, and B is high level, C is high level, D is low level, driving transformer T1, the end A2+ of the same name of T2, A1+, B2+ and B1+ output low level, A2-, A1-, B2-and B1-output high level, driving transformer T3, the end C+ of the same name of T4, C1+, D+ and D1+ output high level, C2-, C1-, D2-and D1-output low level.Q12 and Q22 switching tube accept to drive signal conduction like this, and it is negative level that Q11 and Q21 drive signal, is in cut-off state; Q13 and Q23 switching tube accept to drive signal conduction, and it is negative level that Q14 and Q24 drive signal, is in cut-off state.

So just realize the driving signal of chip U1 is delivered to respectively the switching tube of corresponding two full-bridge circuits after isolating amplification, realized that two full-bridge circuits share one and drive signal, had identical duty ratio.

Be difficult to guarantee that two modules have identical efficient, can carry out the efficient of adjusting module by test method.As working as this scheme of employing at work, if exist the voltage of a module higher, and the voltage of another one module is lower.According to above-mentioned analysis, the module that voltage is high must have bigger efficient.Can increase this module loss, thereby reduce efficient by at the output of this module resistance in parallel like this.When being adjusted in the desired scope, the electric voltage equalization degree of two modules gets final product.

Although according to the module of identical parameters design, because that various parameters can not be accomplished is in full accord, efficient can be not identical.But in certain input voltage and power bracket, its efficient is very approaching, therefore needs the balance resistance power of compensation very little.When design module, if consider in the input voltage certain limit, to have more approaching efficient and the highest efficient when module, will make this scheme have more advantage in engineering.

In sum, it is simple that this technical scheme has control, reliability advantages of higher, the engineering application demand of high-power high voltage input high pressure output occasion in satisfying fully.

Embodiment recited above is described preferred implementation of the present invention; be not that the spirit and scope of the present invention are limited; do not breaking away under the design prerequisite of the present invention; common engineers and technicians make technical scheme of the present invention in this area various modification and improvement; all should fall into protection scope of the present invention; the technology contents that the present invention asks for protection all is documented in claims.

Claims (2)

1. the full-bridge power converter of the input series connection output of connecting, comprise full-bridge power converter and phase-shift control circuit thereof, it is characterized in that: described full-bridge power converter comprises first module and second module with same structure and parameter, and described first module and the shared phase-shift control circuit of second module, wherein said first module comprises the input filter capacitor C1 that is parallel to its input and is parallel to the output filter capacitor Co1 of its output, described second module comprises the input filter capacitor C2 that is parallel to its input and is parallel to the output filter capacitor Co2 of its output, the input of described first module and second module is connected mutually, the output of described first module and second module is series connection mutually also, be that input voltage is added on the described input filter capacitor C1 and input filter capacitor C2 of mutual series connection, and output voltage is added on the described output filter capacitor Co1 and output filter capacitor Co2 of mutual series connection; Described phase-shift control circuit output has PWM to drive signal, and the power switch pipe of described first module and second module shares this identical PWM and drives signal;

Described first module and second module are the zero-voltage zero-current full-bridge power converter that has pulsactor, and the input voltage parameter is direct current 800V ± 20%, and output voltage parameter is DC1000V, output-current rating 10A; As follows for its parameter of each module: switching frequency 26KHz, the former secondary turn ratio of transformer Np: Ns=16: 29, output inductor: 500uH, former limit blocking capacitor: 6.6uF, former limit transformer leakage inductance 1.5uH, former limit filter capacitor 4100uF, output filter capacitor 300uF, it is the IGBT of IKW40N120T2 that power switch pipe adopts model, wherein the power switch pipe Q11 of first module and power switch pipe Q12 form leading-bridge, power switch pipe Q13 and power switch pipe Q14 form lagging leg, the power switch pipe Q21 of second module and power switch pipe Q22 form leading-bridge, power switch pipe Q23 and power switch pipe Q24 form lagging leg, capacitor C b1 and capacitor C b2 are former limit blocking capacitor, inductance L k1 and inductance L k2 are the former limit leakage inductance of transformer, inductance L s1 and inductance L s2 are the pulsactor on former limit, inductance L f1 and capacitor C o1 and inductance L f2 and capacitor C o2 form the output filter circuit of first module and second module respectively, resistance R o is load resistance, isolating transformer TM1 and isolating transformer TM2 are respectively the isolating transformer of first module and second module, diode DR1-DR4 and diode DR5-DR8 form the rectifier bridge of two modules, wherein power switch pipe Q11 and power switch pipe Q21, power switch pipe Q12 and Q22, power switch pipe Q13 and power switch pipe Q23, the driving power switching tube signal of every pair of power switch pipe is identical among power switch pipe Q14 and the power switch pipe Q24, by the output of same phase-shift control circuit and after isolating, be divided into two-way and drive the power switch pipe that signal reaches two full-bridge power converter correspondences, it is that benchmark carries out phase shift to lagging leg driving signal with the leading-bridge that PWM drives signal, if this moment, two full-bridge converter direct-flow input end voltages were respectively Vin1 and Vin2, then this moment, corresponding output voltage size was controlled by duty ratio D, and duty ratio D depends on that lagging leg drives the phase shifting angle θ of signal and leading-bridge signal;

Described phase-shift control circuit comprises sample circuit, the phase shift Drive and Control Circuit, amplifying circuit and 4 driving transformer T1-T4, wherein said sample circuit comprises and is connected in sample resistance R10 and the sample resistance R20 of full-bridge power converter output, sampled signal VUo exports described phase shift Drive and Control Circuit to by the tie point of sample resistance R10 and sample resistance R20,4 drive control signal OUTA of described phase shift Drive and Control Circuit output, OUTB, OUTC and OUTD are connected to 4 inputs of described amplifying circuit respectively, in the described amplifying circuit, triode V1, triode V3, triode V5 and triode V7 are NPN type triode, triode V2, triode V4, triode V6 and triode V8 are the positive-negative-positive triode, diode D1-D8 is fly-wheel diode, described phase shift Drive and Control Circuit adopts chip U1 to constitute, the output OUTA of chip U1 phase-shifted control signal is connected to triode V1, two control utmost points of triode V2, the output OUTB of chip U1 phase-shifted control signal is connected to triode V3, two control utmost points of triode V4, the output OUTC of chip U1 phase-shifted control signal is connected to triode V5, two control utmost points of triode V6, the output OUTD of chip U1 phase-shifted control signal is connected to triode V7, two control utmost points of triode V8, diode D1 and D3 series connection and in parallel with triode V1 and V2 respectively, diode D2 and D4 series connection and in parallel with triode V3 and V4 respectively, diode D5 and D7 series connection and in parallel with triode V5 and V6 respectively, diode D6 and D8 series connection and in parallel with triode V7 and V8 respectively, the series connection node of the fly-wheel diode of above-mentioned series connection constitutes output terminals A successively, B, C and D;

The output terminals A of described amplifying circuit and output B are connected to the input of the driving transformer T1 of the driving transformer T2 of first module and second module, and the output C of described amplifying circuit and output D are connected to the input of the driving transformer T3 of the driving transformer T4 of first module and second module; Driving transformer T2 and driving transformer T1 drive two power switch pipe Q21, Q22 and power switch pipe Q11, the Q12 of the leading-bridge of first module and second module respectively, and driving transformer T3 and driving transformer T4 drive two power switch pipe Q23, Q24 and power switch pipe Q13, the Q14 of the lagging leg of first module and second module respectively; The output terminals A 2+ of driving transformer T1 connects the gate pole of the power switch pipe Q21 of full-bridge circuit, output terminals A 2-connects the emitter of the power switch pipe Q21 of full-bridge circuit, the output terminals A 1+ of driving transformer T2 connects the gate pole of the power switch pipe Q11 of full-bridge circuit, output terminals A 1-connects the emitter of the power switch pipe Q11 of full-bridge circuit, the output B2-of driving transformer T1 connects the gate pole of the power switch pipe Q22 of full-bridge circuit, output B2+ connects the emitter of the power switch pipe Q22 of full-bridge circuit, the output B1-of driving transformer T1 connects the gate pole of the power switch pipe Q12 of full-bridge circuit, output B1+ connects the emitter of the power switch pipe Q12 of full-bridge circuit, the output C2+ of driving transformer T3 connects the gate pole of the power switch pipe Q23 of full-bridge circuit, output C2-connects the emitter of the power switch pipe Q23 of full-bridge circuit, the output C1+ of driving transformer T4 connects the gate pole of the power switch pipe Q13 of full-bridge circuit, output C1-connects the emitter of the power switch pipe Q13 of full-bridge circuit, the output D2-of driving transformer T3 connects the gate pole of the power switch pipe Q24 of full-bridge circuit, output D2+ connects the emitter of the power switch pipe Q24 of full-bridge circuit, the output D1-of driving transformer T4 connects the gate pole of the power switch pipe Q14 of full-bridge circuit, and output D1+ connects the emitter of the power switch pipe Q14 of full-bridge circuit; The input of the former limit winding that driving transformer T1 and T2 are connected with the output terminals A of amplifying circuit is output terminals A 2+, the B2-of its corresponding secondary winding and output terminals A 1+, B1-end of the same name each other respectively, and the input of the former limit winding that driving transformer T3 and T4 are connected with the output C of amplifying circuit is distinguished output C2+, the D2-of its corresponding secondary winding and output C1+, D1-end of the same name each other.

2. the control method of the full-bridge power converter of a series connection as claimed in claim 1 input series connection output, it is characterized in that: the full-bridge power converter setting has first module and second module of same structure and parameter, and described first module and the shared phase-shift control circuit of second module, described phase-shift control circuit arranges sample circuit, phase shift Drive and Control Circuit, amplifying circuit and 4 driving transformer T1-T4, the chip U1 model that constitutes described phase shift Drive and Control Circuit is UC3875, and this control method comprises:

1) input of described first module and second module is connected mutually, the output of described first module and second module is series connection mutually also, described phase-shift control circuit output has PWM to drive signal, and the power switch pipe of described first module and second module shares this identical PWM and drives signal;

2) sampled signal that will be obtained by two sample resistances of full-bridge power converter output exports described phase shift Drive and Control Circuit to, 4 drive control signal of described phase shift Drive and Control Circuit output are connected to 4 inputs of described amplifying circuit respectively, the output terminals A of described amplifying circuit and output B are connected to the input of the driving transformer T2 of the driving transformer T1 of first module and second module, and the output C of described amplifying circuit and output D are connected to the input of the driving transformer T4 of the driving transformer T3 of first module and second module; Output C2+, the C2-of the driving transformer T3 of output terminals A 2+, the A2-of the driving transformer T1 of described second module, B2+, B2-and second module, D2+, D2-are connected to the described second modular power control end of switching tube respectively, and output C1+, the C1-of the driving transformer T4 of output terminals A 1+, the A1-of the driving transformer T2 of described first module, B1+, B1-and first module, D1+, D1-are connected to the described first modular power control end of switching tube respectively; The course of work of wherein said phase-shift control circuit is: when the 18 pin OUTA of chip U1 output high level, the 17th pin OUTB output low level, the 13rd pin OUTC output low level, during the 12nd pin OUTD output high level, triode V1 and triode V4 conducting, triode V5 and triode V8 conducting, driving transformer accepts to drive signal, and OUTA is high level, OUTB is low level, OUTC is low level, OUTD is high level, the output terminals A 2+ of the driving transformer T1 of described second module and the driving transformer T2 of first module, B2+, A1+, B1+ exports high level, output terminals A 2-, B2-, A1-and B1-output low level, the output C2+ of the driving transformer T3 of second module and the driving transformer T4 of first module, D2+, C1+ and D1+ output low level, output C2-, D2-, C1-and D1-output high level, power switch pipe Q11 and power switch pipe Q21 accept to drive signal conduction, it is negative level that power switch pipe Q12 and power switch pipe Q22 accept to drive signal, is in cut-off state; Power switch pipe Q14 and power switch pipe Q24 accept to drive signal conduction, and it is negative level that power switch pipe Q13 and power switch pipe Q23 accept to drive signal, is in cut-off state.

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