CN101071994A - Integrated three-phase AC/DC isolated two-way converter - Google Patents

Abstract

Main circuit of the convertor is composed of switch tubes (VQ1-VQ6), transformers (T1-T3), AC capacitors (C1-C3), bus bar capacitors, resonant capacitances, filter capacitors, filter inductances, and synchronous rectifying tubes. VQ1-VQ6 constitute PWM bridge in three phases. C1-C3 doubles as dc blocking capacitors in DC/DC conversion. Inductances at primary sides of T1-T3 doubles as the input filter inductances. Using simplex full control bridge in three phases, the convertor implements PWM rectification, accomplishes DC/DC isolated conversion as well as transfer energy in bi-direction. Features are: perfective integration structure, high efficiency, simple control, high reliability, small volume, and low cost. The disclosed convertor is applicable to AC/DC isolated power supply in three phases, and UPS power supply widely.

Description

Integrated three-phase AC/DC isolated two-way converter

The present invention relates to a kind of integrated three-phase AC/DC isolated two-way converter.

At present, many fields such as industry need a large amount of isolated power supplys of AC/DC, high-power general employing three-phase alternating current input, two-stage circuit scheme, and as shown in Figure 1, promptly prime is that three-phase is not controlled (or phased) rectification, produces DC bus-bar voltage; The back level is the conversion of DC/DC full-bridge, isolates the output galvanic current and presses.This prime rectifier system produces very big distortion current, causes harmonic pollution in electric power net, reduce power factor, and the DC side energy can't feedback grid.And the three-phase bridge PWM rectifier that occurs in recent years, have input power factor height (being approximately 1), output DC bus-bar voltage stable, can realize advantage such as energy transmitted in both directions, but the overall efficiency and the reliability of itself and late-class circuit are lower, components and parts are many, control is complicated, and volume is big, cost is high.

The objective of the invention is, overcome above-mentioned the deficiencies in the prior art, a kind of integrated three-phase AC/DC isolated two-way converter is provided, it makes full use of single-stage PWM three-phase full-controlled bridge and input LC filtering device, both realized input PWM rectification, export the isolation galvanic current again and pressed, also had the characteristics of energy transmitted in both directions.And control method can adopt existing mature technology, thereby raises the efficiency and reliability, reduces volume and cost.

The present invention realizes like this.

A kind of integrated three-phase AC/DC isolated two-way converter, its main circuit topology divide input side and outlet side two parts, as shown in Figure 2.Input side is by six switching tube (VQ ₁～VQ ₆), three isolating transformer (T ₁, T ₂, T ₃), three ac filter electric capacity (C ₁, C ₂, C ₃) and two dc-link capacitance (C _D1, C _D2) constitute.Three isolating transformer (T ₁, T ₂, T ₃) an elementary winding (L respectively arranged _P1, L _P2, L _P3), a secondary winding (L is respectively arranged _S1, L _S2, L _S3) or a plurality of.Outlet side is by two resonant capacitance (C _R1, C _R2), dc filter capacitor (C _o), two filter inductance (L _O1, L _O2), two synchronous rectifiers (or diode) (VS ₁, VS ₂) constitute.When only requiring that energy transmits from the AC side to the DC side, two synchronous rectifiers can replace with diode, and can remove a resonant capacitance (C _R1).

1, the annexation of these each components and parts of converter

Six switching tube (VQ ₁～VQ ₆) composition three-phase full-controlled bridge, that is: three switching tube (VQ ₁, VQ ₃, VQ ₅) collector electrode be connected together connection bus electric capacity (C _D1) positive pole, and as the  utmost point of dc bus, three switching tube (VQ in addition ₂, VQ ₄, VQ ₆) emitter be connected together connection bus electric capacity (C _D2) negative pole, and as the  utmost point of dc bus; VQ ₁Emitter connect VQ ₂Collector electrode, and as node a, VQ ₃Emitter connect VQ ₄Collector electrode, and as node b, VQ ₅Emitter connect VQ ₆Collector electrode, and as node c; C _D1Negative pole connect C _D2Positive pole, and as mid point N.

Three ac filter electric capacity (C ₁, C ₂, C ₃) an end connect together, and connect mid point N (or the  utmost point of dc bus or  utmost point); C ₁The other end connect transformer (T ₁) elementary winding (L _P1) an end, L _P1Other end connected node a; C ₂The other end connect transformer (T ₂) elementary winding (L _P2) an end, L _P2Other end connected node b; C ₃The other end connect transformer (T ₃) elementary winding (L _P3) an end, L _P3Other end connected node c.Three isolating transformer (T ₁, T ₂, T ₃) secondary winding (L _S1, L _S2, L _S3) series connection, i.e. L _S11. end [this end and L _P1That end of connected node a is an end of the same name] connection L _S22. end, L _S21. end [this end and L _P2That end of connected node b is an end of the same name] connection L _S32. end, L _S31. end [this end and L _P3That end of connected node c is an end of the same name] connection resonant capacitance (C _R2) an end and synchronous rectifier (VS ₂) drain electrode; C _R2The other end connect resonant capacitance (C _R1) an end and synchronous rectifier (V _S1) drain electrode, C _R1The other end connect L _S12. end.When only requiring that energy transmits from the AC side to the DC side, can be with resonant capacitance (C _R1) two terminal shortcircuits connect, and remove C _R1

Two synchronous rectifier (VS ₁, VS ₂) wait composition doubly to flow rectifying and wave-filtering [or being called the conversion of E class] network, that is: two synchronous rectifier (VS ₁, VS ₂) source electrode be connected together, and connect dc filter capacitor (C _o) negative pole; Two filter inductance (L _O1, L _O2) one terminate at together, and connect dc filter capacitor (C _o) positive pole; Filter inductance (L _O1) the other end connect synchronous rectifier (VS ₁) drain electrode, filter inductance (L _O2) the other end connect synchronous rectifier (VS ₂) drain electrode.Load promptly with dc filter capacitor (C _o) parallel connection.

2, the operation principle of this converter

VQ ₁～VQ ₆Form the PWM three-phase full-controlled bridge, C ₁, C ₂, C ₃The capacitance of double as DC/DC isolated variable, T ₁, T ₂, T ₃Primary inductance L _P1, L _P2, L _P3Double as exchanges input filter inductance, secondary winding L _S1, L _S2, L _S3Series connection, its leakage inductance and C _R1, C _R2Form the series resonance link, VS ₁, VS ₂, L _O1, L _O2, C _oConstitute and doubly flow rectifying and wave-filtering [or being called the conversion of E class] network.

At first, this converter has the PWM rectification function.It regulates input power factor and DC bus-bar voltage by the amplitude and the phase place that change modulating wave.

If the main circuit parameter unanimity, that is:

$\left\{\begin{array}{c}{L}_{p1}=L_{p2}=L_{p3}=L_p\\ L_{s1}=L_{s2}=L_{s3}=L_s\\ k_1=k_2=k_3=k\\ C_1=C_2=C_3=C\\ R_1=R_2=R_3=r\end{array}\right.---\left(1\right)$

In the formula: k ₁, k ₂, k ₃---be respectively the first/secondary winding coupling coefficient of three transformers;

R ₁, R ₂, R ₃---be respectively the dead resistance of three primary inductance.

If three-phase input voltage is:

$\left\{\begin{array}{c}{u}_a=U_m\·\sin \mathrm{\ωt}\\ u_b=U_m\·\sin (\mathrm{\ωt}+2\mathrm{\π}/3)\\ u_c=U_m\·\sin (\mathrm{\ωt}-2\mathrm{\π}/3)\end{array}\right.---\left(2\right)$

The three-phase modulations ripple that then is used to produce the PWM drive signal is:

$\left\{\begin{array}{c}{v}_a^{*}=m\·\sin (\mathrm{\ωt}+\mathrm{\δ})\\ v_b^{*}=m\·\sin (\mathrm{\ωt}+2\mathrm{\π}/3+\mathrm{\δ})\\ v_c^{*}=m\·\sin (\mathrm{\ωt}-2\mathrm{\π}/3+\mathrm{\δ})\end{array}\right.---\left(3\right)$

In the formula: m---modulation ratio;

δ---v _PiLag behind u _iThe phase angle, v _PiFor brachium pontis mid point fundamental voltage output of voltage (i=a, b, c).

Document [Li Jianlin etc. three-phase voltage type converter system static mathematical model. electrotechnics journal, 2004,19 (7): 11～15], set up the AC side low frequency equation of Three-Phase PWM Rectifier:

$\left[\begin{array}{c}{i}_a^{\′}\\ i_b^{\′}\\ i_c^{\′}\end{array}\right]=-\frac{r}{L_p}\left[\begin{array}{ccc}1& 0& 0\\ 0& 1& 0\\ 0& 0& 1\end{array}\right]\·\left[\begin{array}{c}{i}_a\\ i_b\\ i_c\end{array}\right]-\frac{U_d}{2L_p}\left[\begin{array}{ccc}1& 0& 0\\ 0& 1& 0\\ 0& 0& 1\end{array}\right]\·\left[\begin{array}{c}{v}_a^{*}\\ v_b^{*}\\ v_c^{*}\end{array}\right]+\frac{1}{L_p}\left[\begin{array}{ccc}1& 0& 0\\ 0& 1& 0\\ 0& 0& 1\end{array}\right]\·\left[\begin{array}{c}{u}_a\\ u_b\\ u_c\end{array}\right]---\left(4\right)$

In the formula: i _a, i _b, i _c---three-phase input current;

i _a', i _b', i _c',---the derivative of three-phase input current.

By formula (4) as seen, Three-Phase PWM Rectifier is stable and main circuit parameter one timing at three phase mains, and three-phase input current is subjected to modulating wave v _a ^*, v _b ^*, v _c ^*Control.Adopt certain control strategy to regulate modulating wave, can make three-phase input current is sinusoidal waveform with the three-phase input voltage homophase.

The document also further provides output DC bus-bar voltage U _dRelation with system parameters:

$U_d=\frac{{6\mathrm{mR}}_d(r\·\cos \mathrm{\δ}+{\mathrm{\ωL}}_p\·\sin \mathrm{\δ})}{8({\mathrm{\ω}}^2{L}_p^2+r^2)+3m^2{R}_{d}r}\·U_m---\left(5\right)$

In the formula: R _d---the equivalent load resistance of PWM rectifier.

By formula (5) as seen, in case main circuit parameter U _m, L _p, r, R _dDetermine, then change modulation ratio m and phase angle δ, can be to DC bus-bar voltage U _dRegulate.

Composite type (4), (5) are regulated modulation ratio m and phase angle δ and not only can be regulated input current waveform and power factor as can be known, can also the stable DC busbar voltage.Control strategy can adopt the two closed-loop controls of voltage-to-current, monocycle control etc.

Secondly, this converter has DC/DC isolated variable function.It regulates output voltage by mode of frequency regulation (PFM), belongs to the resonant mode converter.

From the angle of DC/DC conversion, the one phase equivalent circuit model as shown in Figure 3.In the frame of broken lines is the transformer equivalent model.Among the figure M be transformer just/mutual inductance of secondary winding, $M=k\sqrt{L_p\·L_s};$ V _Pi(i=a, b c) are the added asymmetric square waves voltage of primary.According to the Dai Weinan equivalent theorem, release its equivalent output impedance Z by Fig. 3 ₂With equivalent voltage source V _SiBe respectively:

$Z_2=\mathrm{j\ω}{L}_s+\frac{{\mathrm{\ω}}^2{M}^2}{\mathrm{j\ω}{L}_p+1/\mathrm{j\ωC}}=\mathrm{j\ω}{L}_s(1-\frac{k^2}{1-(1/{\mathrm{\ω}}^{2}C{L}_p)})\≈\mathrm{j\ω}{L}_s(1-k^2)---\left(6\right)$

$V_{\mathrm{si}}=V_{\mathrm{pi}}\·\frac{\mathrm{j\ωM}}{\mathrm{j\ω}(L_p-M)+\mathrm{j\ωM}+(1/\mathrm{j\ωC})}$ (i＝a，b，c)(7)

$\≈V_{\mathrm{pi}}\·\frac{M}{L_p}=V_{\mathrm{Pi}}\·k\·\sqrt{\frac{L_s}{L_p}}=V_{\mathrm{pi}}\·k\·n$

In the formula: k---transformer just/coupling coefficient of secondary winding;

N---transformer/elementary no-load voltage ratio, $n=\sqrt{L_s/L_p}.$

Because the secondary series connection of three transformers, so the total equivalent output impedance of this converter is 3Z ₂Thereby can get the equivalent electric circuit of DC/DC conversion, as shown in Figure 4.Among the figure, ∑ V _sBe total equivalent voltage source, L _rBe total resonant inductance, that is:

∑V _s＝V _sa+V _sb+V _sc(8)

L _r＝3L _s·(1-k ²)?(9)

R _e(t) be equivalent load resistance, press effective value and calculate.Because L _O1, L _O2Parallel connection supplies stream for load and is the constant-current source characteristic, and its size of current is I _o/ 2 (I _oBe load current), R as can be known _e(t) be time dependent; Again because resonant capacitance C _R2The both end voltage sinusoidal waveform that is as the criterion, peak value is 2  U _o(U _oBe VD), so R _e(t) effective value is 4R _L(R _LBe load impedance), maximum is 4  R _L, minimum value is 0.

Adopt triangular wave nature comparison method (analogy method) or symmetric regular-sampled method (digital method), when producing the driving pulse of three-phase bridge, the drive pulse waveform of pipe as shown in Figure 5 on three brachium pontis.Vt is a triangular carrier among the figure, v _a ^*, v _b ^*, v _c ^*Be the three-phase modulations ripple, Vg1, Vg3, Vg5 are respectively VQ ₁, VQ ₃, VQ ₅Driving pulse.As seen, three drive the ripple same-phase, and then the fundamental phase of three brachium pontis mid point output voltages is also identical.

If DC bus-bar voltage U _d(be bus capacitor C _D1, C _D2The voltage sum) constant, three ac filter electric capacity (C ₁, C ₂, C ₃) voltage in a switch periods, change not quite, then can derive three the added asymmetric square waves voltage of primary V _PiFundametal compoment effective value U _Pi ⁽¹⁾For:

$U_{\mathrm{pi}}^{\left(1\right)}=\frac{\sqrt{2}}{\mathrm{\π}}\·U_d\·\sin (D_i\·\mathrm{\π})=\frac{\sqrt{2}}{\mathrm{\π}}\·U_d\·\cos \frac{{\mathrm{\πv}}_i^{*}}{2},(i=a,b,c)---\left(10\right)$

$D_a=\frac{1}{2}+\frac{v_a^{*}}{2},$ $D_b=\frac{1}{2}+\frac{v_b^{*}}{2},$ $D_c=\frac{1}{2}+\frac{v_c^{*}}{2}---\left(11\right)$

In the formula: U _d---DC bus-bar voltage, i.e. capacitor C _D1, C _D2The voltage sum;

D _a, D _b, D _c---be respectively the conducting duty ratio of pipe on three brachium pontis.

Get according to series theory:

$\left\{\begin{array}{c}\cos \frac{\mathrm{\π}{v}_a^{*}}{2}\≈1-\frac{{\mathrm{\π}}^2}{8}{\left(v_a^{*}\right)}^2=1-\frac{{\mathrm{\π}}^2{m}^2}{8}{\sin }^2(\mathrm{\ωt}-\mathrm{\δ})=(1-\frac{{\mathrm{\π}}^2{m}^2}{16})+\frac{{\mathrm{\π}}^2{m}^2}{16}\cos (2\mathrm{\ωt}+2\mathrm{\δ})\\ \cos \frac{{\mathrm{\πv}}_b^{*}}{2}\≈(1-\frac{{\mathrm{\π}}^2{m}^2}{16})+\frac{{\mathrm{\π}}^2{m}^2}{16}\cos (2\mathrm{\ωt}+4\mathrm{\π}/3+2\mathrm{\δ})\\ \cos \frac{\mathrm{\π}{v}_c^{*}}{2}\≈(1-\frac{{\mathrm{\π}}^2{m}^2}{16})+\frac{{\mathrm{\π}}^2{m}^2}{16}\cos (2\mathrm{\ωt}-4\mathrm{\π}/3+2\mathrm{\δ})\end{array}\right.---\left(12\right)$

So have:

$U_{\mathrm{pa}}^{\left(1\right)}+U_{\mathrm{pb}}^{\left(1\right)}+U_{\mathrm{pc}}^{\left(1\right)}\≈\frac{3\sqrt{2}}{\mathrm{\π}}\·U_d\·(1-\frac{{\mathrm{\π}}^2{m}^2}{16})---\left(13\right)$

Get according to formula (7), (8), (13):

$\mathrm{\Σ}{U}_s^{\left(1\right)}=U_{\mathrm{sa}}^{\left(1\right)}+U_{\mathrm{sb}}^{\left(1\right)}+U_{\mathrm{sc}}^{\left(1\right)}\≈k\·n(U_{\mathrm{pa}}^{\left(1\right)}+U_{\mathrm{pb}}^{\left(1\right)}+U_{\mathrm{pc}}^{\left(1\right)})$

$\≈\frac{3\sqrt{2}}{\mathrm{\π}}(1-\frac{{\mathrm{\π}}^2{m}^2}{16})\·k\·n\·U_d---\left(14\right)$

In the formula: U _Si ⁽¹⁾---equivalent voltage source V _SiThe fundametal compoment effective value, (i=a, b, c);

∑ U _s ⁽¹⁾---total equivalent voltage source ∑ V _sThe fundametal compoment effective value.

The input impedance Z that can be got whole load resonant network by Fig. 4 is:

$Z=\mathrm{j\ω}{L}_r+\frac{1}{\mathrm{j\ω}{C}_{r1}}+\frac{R_e}{1+\mathrm{j\ω}{R}_e{C}_{r2}}=\left|Z\right|\·e^{\mathrm{j\ψ}}---\left(15\right)$

So resonant capacitance C _R2Fundamental voltage effective value U _Cr2 ⁽²⁾For:

$U_{\mathrm{Cr}2}^{\left(1\right)}=\frac{K\·\mathrm{\Σ}{U}_s^{\left(1\right)}}{\sqrt{{[1-{\left(\mathrm{\ω}{/\mathrm{\ω}}_0\right)}^2]}^2+{[(K/Q)(\mathrm{\ω}/{\mathrm{\ω}}_0)-(1-K)(K/Q)({\mathrm{\ω}}_0/\mathrm{\ω})]}^2}}---\left(16\right)$

In the formula: C _r---total resonant capacitance, C _r=C _R1C _R2/ (C _R1+ C _R2);

ω ₀---the characteristic angle frequency, ${\mathrm{\ω}}_0=1/\sqrt{L_r{C}_r};$

Q---resonant network quality factor, $Q=R_e\sqrt{C_r/L_r};$

K---capacitance partial pressure ratio, K=C _R1/ (C _R1+ C _R2).

VD U then _oFor:

$U_o=\frac{U_{\mathrm{Cr}2}^{\left(1\right)}}{2}=\frac{\frac{3}{\sqrt{2}\mathrm{\π}}(1-\frac{{\mathrm{\π}}^2{m}^2}{16})\·K\·k\·n\·U_d}{\sqrt{{[1-{\left(\mathrm{\ω}{/\mathrm{\ω}}_0\right)}^2]}^2+[(K/Q)\left(\mathrm{\ω}{/\mathrm{\ω}}_0\right)-(1-K)(K/Q){({\mathrm{\ω}}_0/\mathrm{\ω})]}^2}}---\left(17\right)$

When with C _R1(C when removing _R1Be infinity, K=1), can get:

$U_o=\frac{U_{\mathrm{Cr}2}^{\left(1\right)}}{2}=\frac{\frac{3}{\sqrt{2}\mathrm{\π}}(1-\frac{{\mathrm{\π}}^2{m}^2}{16})\·k\·n\·U_d}{\sqrt{{[1-{(\mathrm{\ω}/{\mathrm{\ω}}_0)}^2]}^2+{\left[(1/Q)\left(\mathrm{\ω}{/\mathrm{\ω}}_0\right)\right]}^2}}---\left(18\right)$

By formula (17), (18) as seen, change switching frequency ω and can change output voltage U _oAs ω 〉=ω ₀The time, ω increases, U _oReduce.This converter is regulated output voltage by frequency modulation(FM) (PFM).

Once more, this converter has energy transmitted in both directions function, the energy two-way flow of promptly secondary DC side and elementary AC side.At this moment, DC side can be described as two E quasi-converters, synchronous rectifier VS ₁, VS ₂With duty ratio 50% alternate conduction, still regulate the size of transmission of power, as long as the driving pulse and the VS of control three-phase full-controlled bridge in the PFM mode ₁, VS ₂Driving pulse synchronous.When only requiring that energy transmits from the AC side to the DC side, two synchronous rectifiers can replace with diode, and can remove resonant capacitance C _R1

At last, because the asymmetric square waves voltage-phase of three brachium pontis mid points output is identical, the high fdrequency component in three primary electric currents equates (also contain three-phase main-frequency in the primary current and exchange the input component).Therefore, three ac filter electric capacity (C ₁, C ₂, C ₃) voltage contains certain common mode ripple voltage, and common mode ripple voltage nature cancellation in the three-phase line voltage, so the ripple voltage that three-phase line voltage has only the PWM rectification to bring.Its three primary inductance can be chosen by the requirement of general PWM rectifier.In order to reduce common mode disturbances to three phase network, can add common-mode filter at input, but this Filter Design list of references [Jiang Yanshu etc. the research .[J of new PWM inverter output passive filter] Electric Machines and Control, 2005,9 (1): 5～10] method.

The present invention compared with prior art has following superiority:

1. the single three-phase full-controlled bridge of this converter using had both been realized the PWM rectification, had finished the DC/DC isolated variable again, and control is simple, reliability and efficient height;

2. the isolating transformer primary inductance double as of this converter exchanges the input filter inductance, and the capacitance of input AC filter capacitor double as DC/DC isolated variable has been realized perfect integratedly, and volume is little, cost is low;

3. this converter belongs to resonant mode, and output synchronous rectifier (or diode) is operated in Zero-voltage soft switch (ZVS) state, has reduced voltage stress and switching loss;

4. this converter can be realized the energy transmitted in both directions of secondary DC side and elementary AC side.

With most preferred embodiment in detail the present invention is described in detail below in conjunction with accompanying drawing.

Fig. 1 is traditional isolated inverter main circuit figure of three-phase AC/DC;

Fig. 2 is this integrated three-phase AC/DC isolated two-way converter main circuit diagram;

Fig. 3 is the one phase equivalent circuit model of the DC/DC conversion of this converter;

Fig. 4 is the whole equivalent circuit diagram of the DC/DC conversion of this converter;

Fig. 5 is the drive waveforms figure of pipe on three brachium pontis of triangular wave comparison method generation.

As shown in Figure 2, this integrated three-phase AC/DC isolated two-way converter, its main circuit topology divide input side and outlet side two parts.Input side is by six switching tube (VQ ₁～VQ ₆), three isolating transformer (T ₁, T ₂, T ₃), three ac filter electric capacity (C ₁, C ₂, C ₃) and two dc-link capacitance (C _D1, C _D2) constitute.Three isolating transformer (T ₁, T ₂, T ₃) an elementary winding (L respectively arranged _P1, L _P2, L _P3), a secondary winding (L is respectively arranged _S1, L _S2, L _S3) or a plurality of.Outlet side is by two resonant capacitance (C _R1, C _R2), dc filter capacitor (C _o), two filter inductance (L _O1, L _O2), two synchronous rectifier (VS ₁, VS ₂) constitute.

The annexation of these each components and parts of converter is six switching tube (VQ ₁～VQ ₆) composition three-phase full-controlled bridge, that is: three switching tube (VQ ₁, VQ ₃, VQ ₅) collector electrode be connected together connection bus electric capacity (C _D1) positive pole, three switching tube (VQ in addition ₂, VQ ₄, VQ ₆) emitter be connected together connection bus electric capacity (C _D2) negative pole; VQ ₁Emitter connect VQ ₂Collector electrode, and as node a, VQ ₃Emitter connect VQ ₄Collector electrode, and as node b, VQ ₅Emitter connect VQ ₆Collector electrode, and as node c; C _D1Negative pole connect C _D2Positive pole, and as mid point N.Three ac filter electric capacity (C ₁, C ₂, C ₃) an end connect together, and connect mid point N; C ₁The other end connect transformer (T ₁) elementary winding (L _P1) an end, L _P1Other end connected node a; C ₂The other end connect transformer (T ₂) elementary winding (L _P2) an end, L _P2Other end connected node b; C ₃The other end connect transformer (T ₃) elementary winding (L _P3) an end, L _P3Other end connected node c.Three isolating transformer (T ₁, T ₂, T ₃) secondary winding (L _S1, L _S2, L _S3) series connection, i.e. L _S11. end [this end and L _P1That end of connected node a is an end of the same name] connection L _S22. end, L _S21. end [this end and L _P2That end of connected node b is an end of the same name] connection L _S32. end, L _S31. end [this end and L _P3That end of connected node c is an end of the same name] connection resonant capacitance (C _R2) an end and synchronous rectifier (VS ₂) drain electrode; C _R2The other end connect resonant capacitance (C _R1) an end and synchronous rectifier (VS ₁) drain electrode, C _R1The other end connect L _S12. end.Two synchronous rectifier (VS ₁, VS ₂) wait composition doubly to flow rectifying and wave-filtering [or being called the conversion of E class] network, that is: two synchronous rectifier (VS ₁, VS ₂) source electrode be connected together, and connect dc filter capacitor (C _o) negative pole; Two filter inductance (L _O1, L _O2) one terminate at together, and connect dc filter capacitor (C _o) positive pole; Filter inductance (L _O1) the other end connect synchronous rectifier (VS ₁) drain electrode, filter inductance (L _O2) the other end connect synchronous rectifier (VS ₂) drain electrode.Load promptly with dc filter capacitor (C _o) parallel connection.

The Reference Design example is: three-phase alternating current input phase voltage u _a, u _b, u _c=220V _AC± 20%, VD U _o=10～40V exports specified power P _Oe=14kW, DC bus-bar voltage U _d=720～880V (setting it changes with the three-phase input voltage size); The primary inductance L _P1=L _P2=L _P2=1.08mH, secondary inductance L _S1=L _S2=L _S2=30 μ H, coupling coefficient k ₁=k ₂=k ₃=0.95; The ac filter capacitor C ₁=C ₂=C ₃=10 μ F, resonant capacitance C _R1=15 μ F, C _R2=6 μ F, the DC filtering inductance L _O1=L _O2=15 μ H.

Claims (1)

1, a kind of integrated three-phase AC/DC isolated two-way converter, its main circuit topology divides input side and outlet side two parts, and input side is by six switching tube (VQ ₁, VQ ₂, VQ ₃, VQ ₄, VQ ₅, VQ ₆), three isolating transformer (T ₁, T ₂, T ₃), three ac filter electric capacity (C ₁, C ₂, C ₃) and two dc-link capacitance (C _D1, C _D2) constitute; Outlet side is by two resonant capacitance (C _R1, C _R2), dc filter capacitor (C _o), two filter inductance (L _O1, L _O2), two synchronous rectifiers [or diode] (VS ₁, VS ₂) constitute; Three isolating transformer (T ₁, T ₂, T ₃) an elementary winding (L respectively arranged _P1, L _P2, L _P3), a secondary winding (L is respectively arranged _S1, L _S2, L _S3) or a plurality of; Three switching tube (VQ ₁, VQ ₃, VQ ₅) collector electrode be connected together connection bus electric capacity (C _D1) positive pole, and as the  utmost point of dc bus, three switching tube (VQ in addition ₂, VQ ₄, VQ ₆) emitter be connected together connection bus electric capacity (C _D2) negative pole, and as the  utmost point of dc bus; Switching tube (VQ ₁) emitter connect switching tube (VQ ₂) collector electrode, and as node a, switching tube (VQ ₃) emitter connect switching tube (VQ ₄) collector electrode, and as node b, switching tube (VQ ₅) emitter connect switching tube (VQ ₆) collector electrode, and as node c; Bus capacitor (C _D1) negative pole connection bus electric capacity (C _D2) positive pole, and as mid point N; Two synchronous rectifier (VS ₁, VS ₂) source electrode be connected together, and connect dc filter capacitor (C _o) negative pole; Two filter inductance (L _O1, L _O2) one terminate at together, and connect dc filter capacitor (C _o) positive pole; Filter inductance (L _O1) the other end connect synchronous rectifier (VS ₁) drain electrode, filter inductance (L _O2) the other end connect synchronous rectifier (VS ₂) drain electrode; It is characterized in that: three ac filter electric capacity (C ₁, C ₂, C ₃) an end connect together, and connect mid point N (or the  utmost point of dc bus or  utmost point); Ac filter electric capacity (C ₁) the other end connect transformer (T ₁) elementary winding (L _P1) an end, elementary winding (L _P1) other end connected node a; Ac filter electric capacity (C ₂) the other end connect transformer (T ₂) elementary winding (L _P2) an end, elementary winding (L _P2) other end connected node b; Ac filter electric capacity (C ₃) the other end connect transformer (T ₃) elementary winding (L _P3) an end, elementary winding (L _P3) other end connected node c; Three isolating transformer (T ₁, T ₂, T ₃) secondary winding (L _S1, L _S2, L _S3) series connection, that is: secondary winding (L _S1) 1. end [this end and elementary winding (L _P1) that end of connected node a is end of the same name] connect secondary winding (L _S2) 2. end, secondary winding (L _S2) 1. end [this end and elementary winding (L _P2) that end of connected node b is end of the same name] connect secondary winding (L _S3) 2. end, secondary winding (L _S3) 1. end [this end and elementary winding (L _P3) that end of connected node c is end of the same name] connect resonant capacitance (C _R2) an end and synchronous rectifier (VS ₂) drain electrode; Resonant capacitance (C _R2) the other end connect resonant capacitance (C _R1) an end and synchronous rectifier (VS ₁) drain electrode, resonant capacitance (C _R1) the other end connect transformer (T ₁) secondary winding (L _S1) 2. end; Also can be with resonant capacitance (C _R1) two terminal shortcircuits connect and save resonant capacitance (C _R1).