CN203352432U - Topological structure of induction type Z-source inverter - Google Patents

Abstract

The utility model provides a topological structure of an induction type Z-source inverter. The topological structure comprises a DC power supply and an inverter bridge. Between the DC power supply and the inverter bridge, just a network formed by inductors and diodes is disposed. The network is provided with n (n>=2) inductors, and 3x(n-1) diodes are matched with the inductors, so that the network of the inductors and diodes is formed. In the network, n inductors form (n-1) circuit units, and each unit comprises two inductors and three diodes. Effects of the topological structure are that capacity cells which are used as necessary components in a Z-source network of a Z-source inverter are removed, service life of a system is prolonged, volume of the system is reduced, and system cost is reduced. The induction type Z-source inverter prevents resonance phenomenon caused by coexistence of the capacitors and inductors, and prevents impact current exists when the Z-source inverter starts. Under same voltage gain conditions, inductive current stress of the induction type Z-source inverter is lower than that of a conventional Z-source inverter and a switching inductance Z-source inverter.

Description

Inductive type Z-source inverter topological structure

Technical field

The utility model relates to a kind of inductive type Z-source inverter topological structure.

Background technology

The topological structure of existing Z-source inverter has multiple, as: traditional Z source inventer as shown in Figure 2, accurate Z-source inverter as shown in Figure 3, switched inductors Z-source inverter as shown in Figure 4 and accurate switched inductors Z-source inverter as shown in Figure 5 etc.Can find out from Fig. 2～5, in above various Z-source inverters, except inductance is arranged, all contain capacity cell.Due to the existence of capacity cell, inevitably have that lifetime of system is shorter, may exist resonance phenomena, system may have impulse current while starting between inductance and electric capacity; In addition, in above Z-source inverter, inductive current stress is larger, and can only change voltage gain by the mode that changes straight-through duty ratio.

Summary of the invention

For above problem, the purpose of this utility model is to provide a kind of inductive type Z-source inverter topological structure, in the Z source network of this inverter, only contains inductance element, has removed the topological structure that must contain capacity cell in Z source network in the past; Voltage gain can be regulated by quantity and two kinds of modes of straight-through duty ratio of adjusting inductance element; Inductive current stress under identical voltage gain condition is less.

For achieving the above object, the technical solution adopted in the utility model is to provide a kind of inductive type Z-source inverter topological structure inductive type Z-source inverter topological structure, this topological structure includes DC power supply, inverter bridge, only contains the network that inductance and diode form between described DC power supply and inverter bridge; Be provided with the individual inductance of n (n >=2) in described network, should have 3 * (n-1) individual diodes to be complementary, and the inductance and the diode network that form, in described network, n inductance forms n-1 circuit unit, and each unit contains two inductance and three diodes; N inductance forms n-1 unit altogether; Two inductance are respectively 1# inductance and 2# inductance; Three diodes are respectively 1# diode, 2# diode and 3# diode; For two adjacent cells, the 1# inductance that the 2# inductance of previous element is a rear unit;

In described network, an end of the 1# inductance of any unit is connected with the anode of 1# diode, and the other end of 1# inductance is connected with the anode of 3# diode with 2#; One end of 2# inductance is connected with the negative electrode of 2# diode with 1#, and the other end of 2# inductance is connected with the negative electrode of 3# diode;

When working in pass-through state, any one unit in described network, 1# and 3# diode current flow, 2# diode cut-off, the 1# in each unit and 2# inductance are and are connected in parallel, now the inductance stored energy; When working in non-pass-through state, any one unit in described network, the cut-off of 1# and 3# diode, the 2# diode current flow, the 1# in each unit and 2# inductance are and are connected in series, and now inductance releases energy to load.

Effect of the present utility model is:

1. removed capacity cell as part necessary in Z source network in Z-source inverter, can extend useful life, the reduction system volume of system and reduce system cost.

2. owing to having removed capacity cell, the inductive type Z-source inverter has been avoided the resonance phenomena that coexists and cause due to electric capacity and inductance.

3. owing to having removed capacity cell, the impulse current that the inductive type Z-source inverter has existed while having avoided Z-source inverter to start.

4. under the condition of identical voltage gain, the inductive current stress of inductive type Z-source inverter is less than traditional Z source inventer and switched inductors Z-source inverter.

The accompanying drawing explanation

Fig. 1 is inductive type Z-source inverter topological structure of the present utility model;

Fig. 2 is the traditional Z source inventer;

Fig. 3 Z-source inverter that is as the criterion;

Fig. 4 is the switched inductors Z-source inverter;

Fig. 5 is the accurate Z-source inverter of switched inductors;

When Fig. 6 is pass-through state of the present utility model, inductive type Z-source inverter topological structure;

When Fig. 7 is non-pass-through state of the present utility model, inductive type Z inverter topology;

When Fig. 8 is different n value of the present utility model, inductive type Z-source inverter voltage gain curve;

Fig. 9 is dissimilar Z-source inverter of the present utility model and the n inductive type Z-source inverter voltage gain correlation curve while getting different value;

Figure 10 is inductive current stress correlation curve in inductive type Z-source inverter of the present utility model and switched inductors Z-source inverter;

Figure 11 is inductive current stress correlation curve in inductive type Z-source inverter of the present utility model and traditional Z source inventer.

Embodiment

By reference to the accompanying drawings inductive type Z-source inverter topological structure of the present utility model is illustrated.

Only contain inductance element in the Z source network of inverter of the present utility model, removed the topological structure that must contain capacity cell in Z source network in the past; Voltage gain can be regulated by quantity and two kinds of modes of straight-through duty ratio of adjusting inductance element; Inductive current stress under identical voltage gain condition is less.

Inductive type Z-source inverter topological structure of the present utility model, this topological structure includes DC power supply, inverter bridge, only contains the network that inductance and diode form between described DC power supply and inverter bridge; Be provided with the individual inductance of n (n >=2) in described network, should have 3 * (n-1) individual diodes to be complementary, and the inductance and the diode network that form, in described network, n inductance forms n-1 circuit unit, and each unit contains two inductance and three diodes; N inductance forms n-1 unit altogether; Two inductance are respectively 1# inductance and 2# inductance; Three diodes are respectively 1# diode, 2# diode and 3# diode; For two adjacent cells, the 1# inductance that the 2# inductance of previous element is a rear unit;

In described network, an end of the 1# inductance of any unit is connected with the anode of 1# diode, and the other end of 1# inductance is connected with the anode of 3# diode with 2#; One end of 2# inductance is connected with the negative electrode of 2# diode with 1#, and the other end of 2# inductance is connected with the negative electrode of 3# diode;

When working in pass-through state, any one unit in described network, 1# and 3# diode current flow, 2# diode cut-off, the 1# in each unit and 2# inductance are and are connected in parallel, now the inductance stored energy;

When working in non-pass-through state, any one unit in described network, the cut-off of 1# and 3# diode, the 2# diode current flow, the 1# in each unit and 2# inductance are and are connected in series, and now inductance releases energy to load.

Described DC power supply (Vdc) is connected between the lower brachium pontis of inductance and diode network and inverter bridge, or is connected between the upper brachium pontis of inductance and diode network and inverter bridge.

As shown in Figure 1, wherein: L ₁=L ₂=L ₃=...=L _n-1=L _n=L, the number that n is inductance.Z source network and inverter bridge that the structure of inductive type Z-source inverter is comprised of inductance and diode form.The Z source network be comprised of inductance and diode is comprised of n inductance and 3 * (n-1) individual diodes.L wherein ₁an end and D _1,1anode be connected, L ₁the other end and D _1,2and D _1,3anode be connected.L ₂an end and D _1,1and D _1,2negative electrode be connected, with D _2,1anode be connected; L ₂the other end and D _2,2and D _2,3anode be connected.By that analogy, known L _n-1an end and D _n-2,1and D _n-2,2negative electrode be connected, with D _n-1,1anode be connected; L ₂the other end and D _n-1,2and D _n-1,3anode be connected.L _nan end and D _n-1,1and D _n-1,2negative electrode be connected, L _nthe other end and D _n-1,3be connected.In addition, DC power supply Vdc can be placed between the lower brachium pontis of inductance and diode network and inverter bridge, also can be placed between the upper brachium pontis of inductance and diode network and inverter bridge.With diode network, equivalence becomes each inductance in parallel, now inductance stored energy to inductance when straight-through.

When working in non-pass-through state, as shown in Figure 7, with diode network, equivalence becomes each inductance series connection to inductance when straight-through to equivalent electric circuit, and now inductance releases energy to load, and the voltage gain of this Z-source inverter is:

$B=\frac{1+(n-1)D}{1-D}$

Wherein: the quantity that n is inductance in the Z source network; D is straight-through duty ratio.

In this Z-source inverter, average inductor current is:

${\mathrm{<figure-callout\; id="1"\; label="I"\; filenames="HDA00003464845000033.png,HDA00003464845000034.png"\; state="\{\{state\}\}">I</figure-callout>}}_1=-\frac{D(\mathrm{nL}+L_L)+L(1-D)}{R_{L}L(1-D)}{V}_{\mathrm{dc}}$

Wherein: the inductance value that L is inductance element in the Z source network; L _lfor load inductance; R _lfor load resistance; V _dcfor DC power supply voltage.

And in inductance network, each inductive current all equates, in this Z-source inverter, the load average electric current is:

${\mathrm{<figure-callout\; id="1"\; label="I"\; filenames="HDA00003464845000033.png,HDA00003464845000034.png"\; state="\{\{state\}\}">I</figure-callout>}}_1=-\frac{L_L(1-D)}{{R_{L}D(\mathrm{nL}+L_L)+R}_L{L}_L(1-D)}{V}_{\mathrm{dc}}$

When load is pure when resistive, inductive current stress and load average electric current are respectively:

${\mathrm{<figure-callout\; id="1"\; label="I"\; filenames="HDA00003464845000033.png,HDA00003464845000034.png"\; state="\{\{state\}\}">I</figure-callout>}}_1=\frac{1+(n-1)D}{R_L(1-D)}{V}_{\mathrm{<figure-callout\; id="1"\; label="dc\; I"\; filenames="HDA00003464845000033.png,HDA00003464845000034.png"\; state="\{\{state\}\}">dc</figure-callout>}}$ $I_{}$ ${}_1=\frac{1+(n-1)D}{R_L}{V}_{\mathrm{dc}}$

Inductive type Z-source inverter voltage gain curve when the n shown in Fig. 8 gets different value, known in figure, the voltage gain that this inverter can be adjusted inverter by adjusting the number that contains inductance in the Z source network and two kinds of modes of straight-through duty ratio; With other type Z-source inverter, compare, the mode of this inverter regulation voltage gain is more diversified.

Inductive type Z-source inverter voltage gain correlation curve when the dissimilar Z-source inverter shown in Fig. 9 and n get different value.The inductive type Z-source inverter can carry out the regulation voltage gain by the quantity of adjusting inductance as we know from the figure, can make this gain be better than the Z-source inverter of other type in certain interval, be suitable for when straight-through change in duty cycle scope than hour situation; In addition, the voltage gain of inductive type Z-source inverter changes steadily than other type Z-source inverter, makes like this its control more convenient.Wherein: SL-ZSI is switched inductors type Z-source inverter; Trad.ZSI is the traditional Z source inventer.

During the different n value of Fig. 9, inductive type Z-source inverter and other Z-source inverter voltage gain correlation curve, inductive current stress correlation curve in Figure 10 inductive type Z-source inverter and switched inductors Z-source inverter, inductive current stress correlation curve in Figure 11 inductive type Z-source inverter and traditional Z source inventer.

From Figure 10 and 11, can find out, in the inductive type Z-source inverter, the inductive current STRESS VARIATION is less of n=1, and 2,3,4,5,6, and during D ∈ [0,0.3], inductive current stress changes between 1～3.6; And the current stress excursion of traditional Z inverter and switched inductors Z-source inverter is (1～+ ∞).And, when identical voltage gain, the current stress of L-ZSI is lower than the current stress of traditional Z SI and SL-ZSI.

Table 1 and table 2 have provided under identical voltage gain condition, the contrast of inductive current stress in inductive type Z-source inverter, traditional Z source inventer and switched inductors Z-source inverter (load is pure resistive).

In table 1 inductive type Z-source inverter and switched inductors Z-source inverter, the inductive current stress ratio

In table 2 inductive type Z-source inverter and traditional Z source inventer, the inductive current stress ratio

Claims (2)

1. an inductive type Z-source inverter topological structure, this topological structure includes DC power supply, inverter bridge, it is characterized in that: only contain the network that inductance and diode form between described DC power supply and inverter bridge; Be provided with the individual inductance of n (n >=2) in described network, should have 3 * (n-1) individual diodes to be complementary, and the inductance and the diode network that form, in described network, n inductance forms n-1 circuit unit, and each unit contains two inductance and three diodes; N inductance forms n-1 unit altogether; Two inductance are respectively 1# inductance and 2# inductance; Three diodes are respectively 1# diode, 2# diode and 3# diode; For two adjacent cells, the 1# inductance that the 2# inductance of previous element is a rear unit;

In described network, an end of the 1# inductance of any unit is connected with the anode of 1# diode, and the other end of 1# inductance is connected with the anode of 3# diode with the 2# diode; One end of 2# inductance is connected with the negative electrode of 2# diode with the 1# diode, and the other end of 2# inductance is connected with the negative electrode of 3# diode;

When working in pass-through state, any one unit in described network, 1# diode and 3# diode current flow, 2# diode cut-off, the 1# inductance in each unit and 2# inductance are and are connected in parallel, now the inductance stored energy;

When working in non-pass-through state, any one unit in described network, the cut-off of 1# diode and 3# diode, the 2# diode current flow, the 1# inductance in each unit and 2# inductance are and are connected in series, and now inductance releases energy to load.

2. inductive type Z-source inverter topological structure according to claim 1, it is characterized in that: described DC power supply (Vdc) is connected between the lower brachium pontis of inductance and diode network and inverter bridge, or is connected between the upper brachium pontis of inductance and diode network and inverter bridge.

Images