CN205911966U - Inductor type Z source dc -to -ac converter of taking a percentage - Google Patents

Abstract

The utility model discloses an inductor type Z source dc -to -ac converter of taking a percentage, including DC power supply udc, three -phase inverter and the inductance Z source network of taking a percentage, DC power supply udc's output and inductance are taken a percentage the input of Z source network and are connected, and the inductance is taken a percentage the output of Z source network and is connected with three -phase inverter's input, and three -phase inverter's output is connected to electric wire netting or load, the Z source network is taken a percentage including take a percentage inductance lt, diode din, diode D1, diode D2, electric capacity C1, electric capacity C2 and inductance L3 to the inductance, and the inductance lt that takes a percentage includes winding N1 and winding N2. The utility model has the advantages of the relative altitude, capacitance voltage stress of stepping up is little, DC voltage high -usage and starting assaults for a short time, can be used to the generation of electricity by new energy and be incorporated into the power networks and occasion such as motor drag.

Description

A kind of tap inductor type z source inventer

Technical field

This utility model is related to a kind of tap inductor type z source inventer, belongs to inverter circuit technical field.

Background technology

Traditional inverter circuit is divided into voltage source and this two class of current source, but this two classes inverter exists and following jointly lacks Point, they or booster type, or buck convertor, and it is unlikely to be lifting/voltage reducing code converter；And their anti-electromagnetism are done The ability disturbed is poor, when leading to bridgc arm short or open circuit due to electromagnetic interference, easily causes current transformer and damages.Thus, in The Peng Fang full professor that Michigan State Usa in 2002 founds university proposes a kind of novel inverter, and this inverter is then the inversion of z source Device.Z source inventer provides a kind of new thinking and theory, can overcome the shortcomings of conventional voltage source and current source inverter it Place.

Z source inventer, since proposing, has had the big model of input voltage with its unique advantage in grid-connected power generation system etc. The occasion enclosing Variation Features is widely used.But existing z source topology still suffers from many defects: 1, boost capability has Limit, to improve boost capability, need to increase straight-through dutycycle, certainly will reduce modulation ratio, the stress of power device can be led to increase； 2nd, discontinuously, DC voltage utilization rate is low for input current；3rd, there is startup impulse circuit, affect inverter performance.

Utility model content

This utility model is in order to overcome the shortcomings of above technology, there is provided a kind of tap inductor type z source inventer, this inversion Utensil has the advantages that step-up ratio is high, capacitance voltage stress is little, DC voltage utilization rate high and startup impact is little, can be used for new energy Source generates electricity and the occasions such as grid-connected and motor drag.

Utility model is summarized:

This utility model passes through to replace an inductance of z source inventer with the passive network including tap inductor, utilizes During Mode variation, tap inductor l_tThe change of winding potential and diode d₁、d₂The change of break-make, will be stored in straight-through period Energy conveying in tap inductor is gone out, and lifts busbar voltage.

This utility model overcomes its technical problem be the technical scheme is that

A kind of tap inductor type z source inventer, including DC source u_dcAnd three-phase inverter, also include inductance tap z source Network, DC source u_dcOutfan be connected with the input of inductance tap z source network, the outfan of inductance tap z source network It is connected with the input of three-phase inverter, the outfan of three-phase inverter connects to electrical network or load；Described inductance tap z source net Network includes tap inductor l_t, diode d_in, diode d₁, diode d₂, electric capacity c₁, electric capacity c₂With inductance l₃, tap inductor l_tBag Include winding n₁With winding n₂；DC source u_dcCathode output end and diode d_inAnode connect, diode d_inNegative electrode divide Not and winding n₁One end, electric capacity c₁One end connect, winding n₁The other end respectively with winding n₂One end, diode d₂Sun Pole connects, winding n₂The other end and diode d₁Anode connect, diode d₁The negative electrode of negative electrode and diode d2, electric capacity One end of c2 is commonly connected to the positive terminal of three-phase inverter, one end of inductance l3 respectively with DC source u_dcNegative pole output End, electric capacity c₂The other end connect, inductance l₃The other end and electric capacity c₁The other end be commonly connected to the negative pole of three-phase inverter End.

According to this utility model preferably, described three-phase inverter is three phase inverter bridge, and three phase inverter bridge includes 6 insulation Grid bipolar transistor, respectively transistor s₁, transistor s₂, transistor s₃, transistor s₄, transistor s₅With transistor s₆, brilliant Body pipe s₁Emitter stage and transistor s₄Colelctor electrode connect after export to electrical network or load, transistor s₂Emitter stage and crystal Pipe s₅Colelctor electrode connect after export to electrical network or load, transistor s₃Emitter stage and transistor s₆Colelctor electrode connect after defeated Go out to electrical network or load, transistor s₁Colelctor electrode, transistor s₂Colelctor electrode and transistor s₃Colelctor electrode be commonly connected to three The positive terminal of phase inverter, transistor s₄Emitter stage, transistor s₅Emitter stage and transistor s₆Emitter stage connect jointly connect It is connected to the negative pole end of three-phase inverter.

The beneficial effects of the utility model are:

Similar with traditional z source inventer, tap inductor type z source inventer of the present utility model is also adopted by shoot-through zero vector and makees For control variable, when circuit parameter determines, busbar voltage amplitude is lifted by the straight-through dutycycle of adjustment；This utility model has Step-up ratio is high, capacitance voltage stress is little, DC voltage utilization rate is high and starts the advantages of impact little, can be used for generation of electricity by new energy With occasions such as grid-connected and motor drag.

Brief description

Fig. 1 is the topology diagram of tap inductor type z source inventer of the present utility model.

Fig. 2 is the equivalent circuit diagram that this utility model is during shoot-through zero vector state in switch periods.

Equivalent circuit diagram when Fig. 3 is traditional zero vector state for this utility model in switch periods.

Equivalent circuit diagram when Fig. 4 is traditional zero vector state for this utility model in switch periods.

Equivalent circuit diagram when Fig. 5 is effective zero vector state for this utility model in switch periods.

Specific embodiment

It is better understood from this utility model for the ease of those skilled in the art, below in conjunction with the accompanying drawings with specific embodiment to this reality It is described in further details with new, following is only exemplary not limit protection domain of the present utility model.

As shown in figure 1, tap inductor type z source inventer of the present utility model, including DC source u_dcAnd three-phase inverter, Also include inductance tap z source network, DC source u_dcOutfan be connected with the input of inductance tap z source network, inductance is taken out The head outfan of z source network is connected with the input of three-phase inverter, and the outfan of three-phase inverter connects to electrical network or load. Described inductance tap z source network includes tap inductor l_t, diode d_in, diode d₁, diode d₂, electric capacity c₁, electric capacity c₂And electricity Sense l₃, tap inductor l_tIncluding winding n₁With winding n₂；DC source u_dcCathode output end and diode d_inAnode connect, Diode d_inNegative electrode respectively with winding n₁One end, electric capacity c₁One end connect, winding n₁The other end respectively with winding n₂'s One end, diode d₂Anode connect, winding n₂The other end and diode d₁Anode connect, diode d₁Negative electrode and two The negative electrode of pole pipe d2, one end of electric capacity c2 are commonly connected to the positive terminal of three-phase inverter, one end of inductance l3 respectively with direct current Power supply u_dcCathode output end, electric capacity c₂The other end connect, inductance l₃The other end and electric capacity c₁The other end be commonly connected to The negative pole end of three-phase inverter.Described three-phase inverter is three phase inverter bridge, and three phase inverter bridge includes 6 insulated gate bipolar crystalline substances Body pipe, respectively transistor s₁, transistor s₂, transistor s₃, transistor s₄, transistor s₅With transistor s₆, transistor s₁Send out Emitter-base bandgap grading and transistor s₄Colelctor electrode connect after export to electrical network or load, transistor s₂Emitter stage and transistor s₅Current collection Pole exports to electrical network or load, transistor s after connecting₃Emitter stage and transistor s₆Colelctor electrode connect after export to electrical network or Load, transistor s₁Colelctor electrode, transistor s₂Colelctor electrode and transistor s₃Colelctor electrode be commonly connected to three-phase inverter Positive terminal, transistor s₄Emitter stage, transistor s₅Emitter stage and transistor s₆Emitter stage connect be commonly connected to three contraries Become the negative pole end of device.

The operation principle of tap inductor type z source inventer of the present utility model:

Assume electric capacity c₁, electric capacity c₂Capacitance when being more than 1000 microfarad, then in switch periods t, capacitance voltage regards For constant, tap inductor type z source inventer includes 3 kinds of on off states: shoot-through zero vector state, tradition in switch periods Zero vector state and effective zero vector state, wherein, traditional zero vector state again can be with scope 2 sub-states, as Fig. 3 and 4 institute Show.

Under straight-through and non-pass-through state, respectively by winding n₁With winding n₁+n₂Work；Because the coefficient of coup is not equal to 1, introduce leakage inductance l_k, magnetizing inductance l_mWith leakage inductance l_kExpression formula be respectively

l_m=k²l₁(1)

l_k=(1-k²)l₁(2)

In formula: k is the coefficient of coup, l₁For winding n₁Inductance value, if turn ratio n=n₂/n₁, then tap inductor two windings Inductance value can be expressed as

$\left\{\begin{array}{c}{l}_2/l_1=n^2{k}^2\\ l_1+l_2=l_t\end{array}\right.---\left(3\right)$

That is,

$\left\{\begin{array}{c}{l}_1=\frac{1}{1+n^2{k}^2}{l}_t\\ l_2=\frac{n^2{k}^2}{1+n^2{k}^2}{l}_t\end{array}\right.---\left(4\right)$

In formula: l₂For winding n₂Inductance value；

(1) state one, shoot-through zero vector state (t₀～t₁):

As shown in Fig. 2 under shoot-through zero vector state, busbar voltage u_pnVia three phase inverter bridge short circuit, during this period, electric capacity C1 voltage is added in winding n₁On, winding n₁Electric current is from minima i_l1(0)Start linearly increasing, work as t=t₁Moment i_l1Reach maximum Value, be

$i_{l1\left(max\right)}=\frac{u_{c1}}{l_1}{t}_0+i_{l1\left(0\right)}=\frac{u_{c1}}{l_1}{d}_{0}t+i_{l1\left(0\right)}---\left(5\right)$

In formula, t₀For leading directly to time, d₀For leading directly to dutycycle,

Winding n₂Induced potential be left "+" right "-", and

u_l2=nu_m=nk²u_c1(6)

In formula, u_mFor the terminal voltage of magnetizing inductance,

Wherein n > 1, therefore diode d₁Cut-off；

Meanwhile, electric capacity c₂Voltage be added in inductance l₃On, inductance l₃Voltage also start linearly increasing from minima, work as t= t₁Moment i_l3Reach maximum, be

$i_{l3\left(max\right)}=\frac{u_{c2}}{l_3}{t}_0+i_{l3\left(0\right)}=\frac{u_{c2}}{l_3}{d}_{0}t+i_{l3\left(0\right)}---\left(7\right)$

Due to u_c1+u_l3＞ u_dc, diode din cut-off.

(2) state two, traditional zero vector state (t₁～t₂):

As shown in Figure 3,4, under traditional zero vector state, three phase inverter bridge is opened a way, t₁Moment, winding n₁And n₂Potential is rapid Decline, and reach reverse maximum, during this period, due to the presence of leakage inductance energy, winding n₁Electric current passes through electric capacity c₂Continue stream Logical；Define in switch periods t, leakage inductance energy is all released to electric capacity c₂Time be t₁=d₁T, wherein d₁For electric capacity c2 Charging interval and switch periods ratio, be now added in winding n₁On voltage be u_c2-u_dc, i_l1Rapid linear decline, i_l1Subtract It is in a small amount

${\mathrm{\δi}}_{l1(-)}=\frac{u_{c2}-u_{dc}}{l_1}{t}_1=\frac{u_{c2}-u_{dc}}{l_1}{d}_{1}t---\left(8\right)$

Afterwards due to u_l2>u_l1(n > 1), diode d₂Current over-zero ends, diode d₁Conducting, as shown in Figure 4；Input electricity Pressure u_dcWith winding n₁、n₂Connect to electric capacity c₂Charge, u_c2=u_dc+u_l1+u_l2, tap inductor l_tElectric current linear decline, and i_l1= i_l2, now, it is added in winding n₁On voltage be

u_l1=u_c2-u_l2-u_dc=u_c2-u_dc-nk²u_l1(9)

Can be obtained according to above formula

$u_{l1}=\frac{u_{c2}-u_{dc}}{1+{\mathrm{nk}}^2}---\left(10\right).$

(3) state three: effectively zero vector state (t₂～t₃):

As shown in figure 5, under effective vector state, three phase inverter bridge is equivalent to a current source, input voltage u_dcWith winding n₂、n₁Series connection powering load, continues to electric capacity c simultaneously₂Voltage, is now added in winding l₁On voltage still meet formula (10), i_l1Continue linear decline, i_l1Reduction amount be

${\mathrm{\δi}}_{l1}=\frac{u_{c2}-u_{dc}}{1+{\mathrm{nk}}^2{l}_1}(1-d_0-d_1)t---\left(11\right)$

In t₁～t₃In time, inductance l₃With input voltage u_dcConnect to electric capacity c₁Charge, be added in inductance l₃On voltage be

u_l3=u_c1-u_dc(12)

Inductance l₃Electric current i_l3Linear reduction, works as t=t₃During the moment, i_l3Reach minima, i_l3Reduction amount be

${\mathrm{\δi}}_{l3}=\frac{u_{c1}-u_{dc}}{l_3}(1-d_0)t---\left(13\right).$

Tap inductor type z source inventer boosting characteristic of the present utility model is as follows:

According to voltage-second balance principle, the winding n of tap inductor in switch periods₁With inductance l₃The average voltage at two ends Expression formula is

$u_{c1}{d}_0-(u_{c2}-u_{dc})d_1-\frac{u_{c2}-u_{dc}}{1+{\mathrm{nk}}^2}(1-d_0-d_1)=0---\left(14\right)$

u_c2d₀-(u_c1-u_dc)(1-d₀)=0 (15)

During effective vector state, the voltage at three-phase inversion brachium pontis two ends is

${\hat{u}}_{pn}=u_{c1}+u_{c2}-u_{dc}---\left(16\right)$

Calculate and obtain after arranging

$u_{c1}=\frac{1-d_0+{\mathrm{nk}}^2{d}_1}{1-2d_0+{\mathrm{nk}}^2(d_1-d_0{d}_1-d_0^2)}{u}_{dc}---\left(17\right)$

$u_{c2}=\frac{1-d_0+{\mathrm{nk}}^2(d_0+d_1-d_0{d}_1-d_0^2)}{1-2d_0+{\mathrm{nk}}^2(d_1-d_0{d}_1-d_0^2)}{u}_{dc}---\left(18\right)$

${\hat{u}}_{pn}=\frac{1+{\mathrm{nk}}^2(d_0+d_1)}{1-2d_0+{\mathrm{nk}}^2(d_1-d_0{d}_1-d_0^2)}{u}_{dc}---\left(19\right)$

If working as d₁Then have when=0, k=1

$u_{c1}=\frac{1-d_0}{1-2d_0-{\mathrm{nd}}_0^2}{u}_{dc}---\left(20\right)$

$u_{c2}=\frac{1-(1-n)d_0-{\mathrm{nd}}_0^2}{1-2d_0-{\mathrm{nd}}_0^2}{u}_{dc}---\left(21\right)$

${\hat{u}}_{pn}=\frac{1+{\mathrm{nd}}_0}{1-2d_0-{\mathrm{nd}}_0^2}{u}_{dc}---\left(22\right).$

Similar with traditional z source inventer, tap inductor type z source inventer of the present utility model is also adopted by shoot-through zero vector and makees For control variable, when circuit parameter determines, busbar voltage amplitude is lifted by the straight-through dutycycle of adjustment.It should be noted that Shoot-through zero vector is injection in traditional zero vector, and shoot-through zero vector is equivalent to the action effect of load with traditional zero vector, It is all to make load short circuits, natural afterflow, so the shoot-through zero vector of injection does not affect on inverter ac output voltage.This reality Have the advantages that step-up ratio is high, capacitance voltage stress is little, DC voltage utilization rate high and startup impact is little with new, can be used for Generation of electricity by new energy and the occasions such as grid-connected and motor drag.

Above only describes ultimate principle of the present utility model and preferred implementation, those skilled in the art can be according to above-mentioned Many changes and improvements are made in description, and these changes and improvements should belong to protection domain of the present utility model.

Claims (2)

1. a kind of tap inductor type z source inventer, including DC source u_dcWith three-phase inverter it is characterised in that: also include electricity Sense tap z source network, DC source u_dcOutfan be connected with the input of inductance tap z source network, inductance tap z source network Outfan be connected with the input of three-phase inverter, the outfan of three-phase inverter connects to electrical network or load；

Described inductance tap z source network includes tap inductor l_t, diode d_in, diode d₁, diode d₂, electric capacity c₁, electric capacity c₂ With inductance l₃, tap inductor l_tIncluding winding n₁With winding n₂；

DC source u_dcCathode output end and diode d_inAnode connect, diode d_inNegative electrode respectively with winding n₁One End, electric capacity c₁One end connect, winding n₁The other end respectively with winding n₂One end, diode d₂Anode connect, winding n₂ The other end and diode d₁Anode connect, diode d₁Negative electrode and diode d₂Negative electrode, electric capacity c₂One end jointly connect It is connected to the positive terminal of three-phase inverter, inductance l₃One end respectively with DC source u_dcCathode output end, electric capacity c₂Another End connects, inductance l₃The other end and electric capacity c₁The other end be commonly connected to the negative pole end of three-phase inverter.

2. tap inductor type z source inventer according to claim 1 it is characterised in that: described three-phase inverter be three-phase Inverter bridge, three phase inverter bridge includes 6 insulated gate bipolar transistors, respectively transistor s₁, transistor s₂, transistor s₃, brilliant Body pipe s₄, transistor s₅With transistor s₆, transistor s₁Emitter stage and transistor s₄Colelctor electrode connect after export to electrical network or Load, transistor s₂Emitter stage and transistor s₅Colelctor electrode connect after export to electrical network or load, transistor s₃Emitter stage With transistor s₆Colelctor electrode connect after export to electrical network or load, transistor s₁Colelctor electrode, transistor s₂Colelctor electrode with brilliant Body pipe s₃Colelctor electrode be commonly connected to the positive terminal of three-phase inverter, transistor s₄Emitter stage, transistor s₅Emitter stage with Transistor s₆Emitter stage connect and be commonly connected to the negative pole end of three-phase inverter.