CN203504449U - Switch inductance gamma-type Z-source inverter topology structure - Google Patents

Abstract

The utility model discloses a switch inductance gamma-type Z-source inverter topology structure comprising a DC power source and an inverter bridge. The topology structure is characterized in that a gamma-type Z-source network comprising a switch inductance unit is added between the DC power source and the inverter bridge, i.e., the gamma-type Z-source network comprising the switch inductance unit is connected at the front end of the inverter bridge. The beneficial effects of the switch inductance gamma-type Z-source inverter topology structure are that: during a voltage amplification process of an inverter, the capacitance voltage stress of the Z-source network is maintained to be twice the DC power source voltage, so that a condition that the capacitance voltage stress of a conventional Z-source inverter increases as the shoot-through duty ratio increases is prevented; compared with a conventional Z-source inverter and a switch inductance Z-source inverter, under the same voltage gain, the inductance current stress is reduced; the voltage gain is increased when the shoot-through duty ratio is quite small; and the influence on the inverter bridge by the impact current when a system is started is prevented.

Description

Switched inductors Γ type Z-source inverter topological structure

Technical field

The utility model relates to a kind of switched inductors Γ 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.From Fig. 2～5, can find out, in above various Z-source inverters, except having inductance, all contain two capacity cells, and the voltage stress of electric capacity increases along with the increase of straight-through duty ratio.Because capacitance voltage stress range is larger, this will reduce the useful life of electric capacity, and has limited the size of straight-through duty ratio; While starting, may there is impulse current in system; In addition, in above Z-source inverter, inductive current stress is larger.

Summary of the invention

For above problem, the purpose of this utility model is to provide a kind of topological structure of switched inductors Γ type Z-source inverter, in the Z source network of this inverter, only contain a capacity cell, and to make capacitance voltage stress be certain value, and reduced inductive current stress under identical voltage gain condition.

For achieving the above object, the technical solution adopted in the utility model is: a kind of switched inductors Γ type Z-source inverter topological structure, this topological structure includes DC power supply, inverter bridge, it is characterized in that: between described DC power supply and inverter bridge, add a Γ type Z source network that contains switched inductors unit, the front end in inverter bridge connects the Γ type Z source network that contains switched inductors unit.

The described Γ type Z source network that contains switched inductors unit comprises three inductance, an electric capacity and four diodes; If three inductance are respectively 1# inductance L ₁, 2# inductance L ₂with 3# inductance L ₃; Four diodes are respectively 1# diode D ₁, 2# diode D ₂, 3# diode D ₃with 4# diode D ₄; An electric capacity is 1# capacitor C;

Described 1# diode D ₁anode be connected with the positive pole of DC power supply Vdc, D ₁negative electrode respectively with 1# inductance L ₁one end, 2# inductance L ₂one end and 2# diode D ₂anode be connected; 1# inductance L ₁the other end be connected with the positive pole of capacitor C, the negative pole of capacitor C is connected with the negative pole of DC power supply Vdc and the lower brachium pontis of inverter bridge; 2# inductance L ₂the other end and 3# diode D ₃with 4# diode D ₄anode be connected; 3# inductance L ₃one end and 2# diode D ₂negative electrode and 3# diode D ₃negative electrode be connected, 3# inductance L ₃the other end and 4# diode D ₄negative electrode and the upper brachium pontis of inverter bridge be connected.

Described L ₁=L ₂=L ₃=L, L is the inductance value of inductance element in the Γ type Z source network that contains switched inductors unit.

The utlity model has following advantage and technique effect:

1. by containing two electric capacity in traditional Z source network, be kept to and only contain an electric capacity, and capacitance voltage stress is certain value in the process of boosting, can extend useful life, the reduction system volume of system and reduce system cost.

2. under identical voltage gain, capacitance voltage stress is certain value, compares and has reduced capacitance voltage stress with other type Z-source inverter.

3. due to the front end of switched inductors unit in inverter bridge, so the impulse current to inverter bridge when this inverter can avoid system to start.

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

Accompanying drawing explanation:

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

Fig. 2 is traditional Z source inventer;

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

Fig. 4 is switched inductors Z-source inverter;

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

Fig. 6 be the utility model when pass-through state, switched inductors Γ type Z-source inverter topological structure;

Fig. 7 be the utility model when non-pass-through state, switched inductors Γ type Z inverter topology;

Fig. 8 is traditional Z source inventer, switched inductors Z-source inverter and switched inductors Γ type Z-source inverter voltage gain correlation curve;

Fig. 9 is traditional Z source inventer, switched inductors Z-source inverter and switched inductors Γ type Z-source inverter capacitance voltage stress correlation curve;

Figure 10 is traditional Z source inventer and switched inductors Γ type Z-source inverter inductive current stress correlation curve;

Figure 11 is switched inductors Z-source inverter and switched inductors Γ type Z-source inverter inductive current stress correlation curve.

Embodiment

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

In the switched inductors Γ type Z source network of inverter of the present utility model, only contain a capacity cell; In the process of boosting, capacitance voltage stress is certain value; Inductive current stress under identical voltage gain condition is less.

As shown in Figure 1: a kind of switched inductors Γ type Z-source inverter topological structure, this topological structure includes DC power supply, inverter bridge.Between described DC power supply and inverter bridge, add a Γ type Z source network that contains switched inductors unit, the front end in inverter bridge connects the Γ type Z source network that contains switched inductors unit.The described Γ type Z source network that contains switched inductors unit comprises three inductance, an electric capacity and four diodes; Wherein, three inductance are respectively 1# inductance L ₁, 2# inductance L ₂with 3# inductance L ₃; Four diodes are respectively 1# diode D ₁, 2# diode D ₂, 3# diode D ₃with 4# diode D ₄; An electric capacity is 1# capacitor C;

Described 1# diode D ₁anode be connected with the positive pole of DC power supply Vdc, D ₁negative electrode respectively with 1# inductance L ₁one end, 2# inductance L ₂one end and 2# diode D ₂anode be connected; 1# inductance L ₁the other end be connected with the positive pole of capacitor C, the negative pole of capacitor C is connected with the negative pole of DC power supply Vdc and the lower brachium pontis of inverter bridge; 2# inductance L ₂the other end and 3# diode D ₃with 4# diode D ₄anode be connected; 3# inductance L ₃one end and 2# diode D ₂negative electrode and 3# diode D ₃negative electrode be connected, 3# inductance L ₃the other end and 4# diode D ₄negative electrode and the upper brachium pontis of inverter bridge be connected.

Described L ₁=L ₂=L ₃=L, L is the inductance value of inductance element in the Γ type Z source network that contains switched inductors unit.

As shown in Figure 6: when working in pass-through state, 1#, 2# and 4# diode D in Γ type Z source network ₁, D ₂and D ₄conducting, 3# diode D ₃cut-off, wherein 2# and 3# inductance L ₂and L ₃be and be connected in parallel, now inductance stored energy;

As shown in Figure 7: when working in non-pass-through state, 1#, 2# and 4# diode D in Γ type Z source network ₁, D ₂and D ₄cut-off, 3# diode D ₃conducting, wherein 2# and 3# inductance L ₂and L ₃be and be connected in series, now inductance releases energy to load, and the voltage gain of this Z-source inverter is:

$B=\frac{2+D}{1-D}$

Wherein: B is voltage gain; D is straight-through duty ratio.

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

$I_L=\frac{L_{l}D+L(2+D)}{{\mathrm{LR}}_l}{V}_{\mathrm{dc}}$

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

Load average electric current is:

$I_l=(2+D)\frac{V_{\mathrm{dc}}}{R_l}$

When load is pure when resistive, inductive current stress is:

$I_L=\frac{2+D}{1-D}\frac{V_{\mathrm{dc}}}{R_l}$

The voltage gain correlation curve of switched inductors Γ type Z-source inverter, traditional Z source inventer and switched inductors Z-source inverter as shown in Figure 8, known in figure, when little straight-through duty ratio, the voltage gain of switched inductors Γ type Z-source inverter is larger.

The capacitance voltage stress correlation curve of switched inductors Γ type Z-source inverter, traditional Z source inventer and switched inductors Z-source inverter as shown in Figure 9.Visible, the capacitance voltage stress of switched inductors Γ type Z-source inverter does not change with the variation of straight-through duty ratio, and the capacitance voltage stress range of other two kinds of Z-source inverters is larger.Wherein: SL-ZSI is switched inductors type Z-source inverter; Trad.ZSI is traditional Z source inventer.

Inductive current stress correlation curve in switched inductors Γ type Z-source inverter as shown in figure 10 and traditional Z source inventer, inductive current stress correlation curve in the switched inductors Γ type Z-source inverter shown in Figure 11 and switched inductors Z-source inverter and traditional Z source inventer.

From Fig. 8,10 and 11, can find out, in switched inductors Γ type Z-source inverter, inductive current STRESS VARIATION is less, and under identical voltage gain condition, its inductive current stress is less than the inductive current stress in traditional Z source inventer and switched inductors Z-source inverter.

Claims (3)

1. a switched inductors Γ type Z-source inverter topological structure, this topological structure includes DC power supply, inverter bridge, it is characterized in that: between described DC power supply and inverter bridge, add a Γ type Z source network that contains switched inductors unit, the front end in inverter bridge connects the Γ type Z source network that contains switched inductors unit.

2. switched inductors Γ type Z-source inverter topological structure according to claim 1, is characterized in that: described in contain switched inductors unit Γ type Z source network comprise three inductance, an electric capacity and four diodes; If three inductance are respectively 1# inductance L ₁, 2# inductance L ₂with 3# inductance L ₃; Four diodes are respectively 1# diode D ₁, 2# diode D ₂, 3# diode D ₃with 4# diode D ₄; An electric capacity is 1# capacitor C;

Described 1# diode D ₁anode be connected with the positive pole of DC power supply Vdc, D ₁negative electrode respectively with 1# inductance L ₁one end, 2# inductance L ₂one end and 2# diode D ₂anode be connected; 1# inductance L ₁the other end be connected with the positive pole of capacitor C, the negative pole of capacitor C is connected with the negative pole of DC power supply Vdc and the lower brachium pontis of inverter bridge; 2# inductance L ₂the other end and 3# diode D ₃with 4# diode D ₄anode be connected; 3# inductance L ₃one end and 2# diode D ₂negative electrode and 3# diode D ₃negative electrode be connected, 3# inductance L ₃the other end and 4# diode D ₄negative electrode and the upper brachium pontis of inverter bridge be connected.

3. switched inductors Γ type Z-source inverter topological structure according to claim 2, is characterized in that: described L ₁=L ₂=L ₃=L, L is the inductance value of inductance element in the Γ type Z source network that contains switched inductors unit.

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