CN205159073U - Novel distribution transformer - Google Patents

Abstract

The utility model discloses a novel distribution transformer, transformer primary side winding is D / type connection or ordinary D type is connected, the vice limit of transformer winding is connected for the zn type, D / type is connected and is done: former limit A, B and C three -phase winding difference suit are on three core limbs of three -phase iron core, the B phase winding has extension winding AD and EB, extend winding AD and EB cross arrangement on B looks iron core, a congruence C phase winding is taken respectively and is extended winding alpha D and beta E, extends winding alpha D and beta E and distinguishes the suit in A congruence C mutually on the iron core. Primary side winding D / connection, vice limit winding zn connection make up into D /, zn connection high impedance distribution transformer can realize the balanced transform of two -phase / triphase, the primary side winding D connection, vice limit winding zn connection makes up into D, zn connection high impedance distribution transformer, three -phase / triphase symmetry transformation can be realized to this transformer. The utility model discloses except that the intrinsic electric quantity mapping function of transformer, the effect of inductance filtering in addition.

Description

New distribution transformer

Technical field

The utility model relates to a kind of new distribution transformer with filter function, belongs to for distribution technique field.

Background technology

The development of contemporary science and technology particularly power electronic technology makes the use of various nonlinear load in electric power system more and more general, thereupon that the pollution of various harmonic wave to system is more and more serious, started to have had influence on the voltage distribution system inseparable with people's daily life, the method that existing harmonic carcellation pollutes is install passive or active filter in systems in which additional substantially.Although there is certain effect, add a lot of cost undoubtedly.

In the electric railway of China, what originally friendship-straight type the electric locomotive of a large amount of employing phase control rectifier technology used produced is mostly low-order harmonic.Traction substation is eliminated by installing filter, does not substantially affect the low-voltage distribution system of traction substation.Along with a large amount of employings of the AC-DC-AC type electric locomotive of employing SPWM commutation technique, although low-order harmonic greatly reduces to settle bring a large amount of high order harmonic component, have a strong impact on the quality of power supply of low-voltage distribution system, even burn the control appliance of electric substation because of higher harmonic resonance voltage.

At present, at the traction substation adopting balance traction transformer to power, house transformer is mostly traditional inverse Scott connection, although this transformer can realize the balanced transformation of two-phase/three-phase, there is following open defect:

1, three-phase side neutral point above earth potential is non-vanishing, does not have nature neutral point;

2, all there is no the coil of delta connection in former auxiliary winding, path cannot be provided for zero-sequence current;

3, cannot eliminate flow into house transformer reflux over the ground produce residual voltage to the harmful effect of electric substation's threephase load;

4, the higher harmonic voltage of the intrusion electric substation produced in high-speed railway cannot be suppressed.

Adopting the electric substation of other traction transformer, house transformer is mostly common D, yn connection distribution transformer, and this transformer refluxes over the ground and the impact of high order harmonic component cannot be eliminated.

In view of above reason, propose a kind of distribution transformer of novel wire connecting way herein, the electrical transformation function that this transformer not only has transformer intrinsic, also have the effect of inductor filter concurrently, be particularly useful for high-speed electric railway, can reflux with reducing and the impact of higher harmonic voltage.

Utility model content

Technical problem to be solved in the utility model is, for the deficiencies in the prior art, provide a kind of new distribution transformer, its transformer primary side and secondary adopt new mode of connection combination, decrease the harmful effect of harmonic wave to low-voltage distribution system, different confession distribution systems can be adapted to.

The technical solution of the utility model is:

A kind of new distribution transformer, described transformer primary side winding is that D ' type connects, or common D type connects; Transformer secondary winding is that zn type connects;

Described D ' type connects: former limit A, B and C three-phase windings is set with on three core limbs of three-phase iron core; B phase winding is with extension winding AD and EB; Extend winding AD and EB arranged crosswise on B phase iron core; A phase and C phase winding are with respectively and are extended winding α D and β E; Extending winding α D and β E is set with in A phase and C phase iron core; In three-phase windings, the end of a phase winding and the head end of another phase winding connect together, and connect into a closed-loop path in turn, are connected into triangle △ ABC; Wire is drawn from terminal α, β and C; Original edge voltage U α C and U β C differs 90 ° of electric angles; The equivalent impedance ratio of former limit A, B, C three-phase windings (distinguishing winding AX, BY and the CZ in corresponding diagram 1 and Fig. 2) is: 1:Kz:1, Kz span is can freely choose during design of transformer; △ ABC winding phase voltage equals the number of turn of former limit A, B and C three-phase windings is w1; The number of turn that A phase extends winding α D and β E with C phase is W5, and the number of turn that B phase extends winding AD and EB is W4; Following relation is had between each umber of turn:

W4＝K4×W1

W5＝K5×W1

$K4=\sqrt{3}/(Kz+2)$

$K5=(\sqrt{3}+1-Kz)/(Kz+2)$

Described common D type connects: former limit A, B and C three-phase windings is set with on three core limbs of three-phase iron core; In three-phase windings, the end of a phase winding and the head end of another phase winding connect together, and connect into a closed-loop path in turn, are connected into triangle △ ABC; Wire is drawn from terminal A, B and C; Former limit three-phase voltage differs 120 ° of electric angles; The number of turn of former limit A, B and C three-phase windings is w1;

Described zn type connects: the meander configuration wiring that neutral point is drawn; Comprise a, b and c three-phase windings, every phase winding is divided into 2 parts: main winding and Phase shift winding, is set on the core limb of three-phase iron core respectively successively; The end of one phase main winding and the end of another phase Phase shift winding connect together, and the head end of this another phase Phase shift winding meets neutral point o; Neutral point o ground connection; The number of turn of three-phase main winding is w2, and the number of turn of three-phase phase shifting winding is w3, w2 and w3 is determined by the θ angle selected, w1 and transformer transformation ratio.

Described phase shifting angle θ selects as required.Principle of the present utility model is:

Former limit winding D ' connection, vice-side winding zn connection is combined into D ', zn connection high impedance distribution transformer.This transformer can realize the balanced transformation of two-phase/three-phase, and original edge voltage U α C and U β C differs 90 ° of electric angles, is suitable for the traction substation adopting balance traction transformer.The zero-sequence current magnetic flux coming from contact nets in electrified railways achieves self-balancing, secondary neutral point no current in the D ' winding of former limit.Secondary is the indentation wiring (zn connection) at phase shift θ angle of band neutral point, and three characteristics of the middle term laod unbalance and the zero-sequence current magnetic flux that produces are cancelled out each other in every phase vice-side winding with the magnetic flux that entoilage backflow produces that contacts by neutral point.Higher harmonic voltage from former limit contact line drops on the internal high-impedance of transformer, can not be delivered to vice-side winding, and secondary three-phase output voltage can keep balance.

Former limit winding D connection, vice-side winding zn connection is combined into D, zn connection high impedance distribution transformer.This transformer can realize the symmetry transformation of three-phase/three-phase, and former limit three-phase voltage differs 120 ° of electric angles, is suitable for adopting the traction substation of other traction transformer and general electric power system.The zero-sequence current coming from system connects circulation in winding at former limit D, does not produce residual voltage.Secondary is the indentation wiring (zn connection) at phase shift θ angle of band neutral point, three characteristics of the middle term laod unbalance and the zero-sequence current magnetic flux that produces is cancelled out each other in every phase vice-side winding.Higher harmonic voltage from former edge system drops on the internal high-impedance of transformer, can not be delivered to vice-side winding, and secondary three-phase output voltage can keep balance.

Beneficial effect:

A kind of new distribution transformer of the present utility model, the value that its short-circuit impedance specifies much larger than current standard, is also greater than its load-carrying impedance.Except the electrical transformation function that transformer is intrinsic, also has the effect of inductor filter.

Transformer primary side and secondary adopt new mode of connection combination, decrease the harmful effect of harmonic wave to low-voltage distribution system, can adapt to different confession distribution systems.

When transformer primary side winding adopts D ' connection (Fig. 1 or Fig. 2), the balanced transformation of two-phase/three-phase can be realized, for the electric substation that electric railway adopts balance traction transformer to power.

When transformer primary side winding adopts common D connection (Fig. 3), the symmetry transformation of three-phase/three-phase can be realized, in any electric power system.

Accompanying drawing explanation

Fig. 1 is former limit winding D ' connection principle and voltage, current vector figure;

Fig. 2 is time former limit winding D ' elementary diagram;

Fig. 3 is former limit winding D elementary diagram;

Fig. 4 is vice-side winding principle and voltage vector diagram;

Fig. 5 is each coil connection diagram of D ' wiring former limit winding;

Fig. 6 is each coil connection diagram of vice-side winding;

Fig. 7 is time D ' wiring former limit winding each coil connection diagram.

Embodiment

Below in conjunction with accompanying drawing, the utility model is described in further detail.

A kind of new distribution transformer, described transformer primary side winding is that D ' type connects (Fig. 1 or Fig. 2), or common D type connects (Fig. 3); Transformer secondary winding is that zn type connects;

Described D ' type connects: former limit A, B and C three-phase windings (winding AX, winding BY and winding CZ respectively in corresponding diagram 1, Fig. 2) is set with on three core limbs of three-phase iron core; B phase winding is with extension winding AD and EB; Extend winding AD and EB arranged crosswise on B phase iron core; A phase and C phase winding are with respectively and are extended winding α D and β E; Extending winding α D and β E is set with in A phase and C phase iron core; In three-phase windings, the end of a phase winding and the head end of another phase winding connect together, and connect into a closed-loop path in turn, are connected into triangle △ ABC; Wire is drawn from terminal α, β and C; Original edge voltage U α C and U β C differs 90 ° of electric angles (i.e. voltage phase difference 90 ° of electric angles between terminal α-C, β-C); The equivalent impedance ratio of former limit A, B, C three-phase windings (distinguishing winding AX, BY and the CZ in corresponding diagram 1 and Fig. 2) is: 1:Kz:1, Kz span is can freely choose during design of transformer; △ ABC winding phase voltage (namely in Fig. 1, Fig. 2 between terminal A-X, B-Y, C-Z voltage) equals the number of turn of former limit A, B and C three-phase windings is w1; The number of turn that A, C phase extends winding α D and β E is W5, and the number of turn that B phase extends winding AD and EB is W4; Following relation is had between each umber of turn:

W4＝K4×W1

W5＝K5×W1

$K4=\sqrt{3}/(Kz+2)$

$K5=(\sqrt{3}+1-Kz)/(Kz+2);$

When time, connection principle is reduced to Fig. 2.

Described common D type connects: former limit A, B and C three-phase windings (i.e. winding AC, winding BA and winding CB respectively in corresponding diagram 3) is set with on three core limbs of three-phase iron core; In three-phase windings, the end of a phase winding and the head end of another phase winding connect together, and connect into a closed-loop path in turn, are connected into triangle △ ABC; Wire is drawn from terminal A, B and C; Former limit three-phase voltage differs 120 ° of electric angles; The number of turn of former limit A, B and C three-phase windings is w1;

Described zn type connects: the meander configuration wiring that neutral point is drawn; Comprise a, b and c three-phase windings, every phase winding is divided into 2 parts: main winding and Phase shift winding, is set on the core limb of three-phase iron core respectively successively; The end of one phase main winding and the end of another phase Phase shift winding connect together, and the head end of this another phase Phase shift winding meets neutral point o; Neutral point o ground connection; The number of turn of three-phase main winding is w2, and the number of turn of three-phase phase shifting winding is w3, w2 and w3 is determined by the θ angle selected, w1 and transformer transformation ratio.

Described phase shifting angle θ selects as required.

The connection principle of D ', zn connection distribution transformer is see Fig. 1, Fig. 2, Fig. 4.In figure, W1 ~ W5 is umber of turn, U and I is respectively voltage and current, and θ is winding phase shift angle, and phase shifting angle θ can select as required.This transformer requires that the equivalent impedance ratio of former limit A, B, C three-phase windings (winding AX, winding BY, winding CZ respectively in corresponding diagram 1, Fig. 2) is: 1:Kz:1, Kz span is can freely choose during design of transformer.△ ABC winding phase voltage (namely in Fig. 1, Fig. 2 between terminal A-X, B-Y, C-Z voltage) equals the number of turn that A, C phase extends winding α D and β E is W5, and the number of turn that B phase extends winding AD and EB is W4; Following relation is had between each umber of turn:

W4＝K4×W1

W5＝K5×W1

$K4=\sqrt{3}/(Kz+2)$

$K5=(\sqrt{3}+1-Kz)/(Kz+2);$

Vice-side winding number of turn W2 and W3 is determined by the θ angle selected, W1 and transformer transformation ratio.Other calculation of parameter of this transformer and common transformer are as good as, and its impedance occurrence can be determined according to harmonic spectrum.The connection of each coil of former limit D ' winding can refer to Fig. 5, wherein extend winding AD and EB must on B phase iron core arranged crosswise, coupling is closely.When getting time, W5=0, the connection of each coil of former limit D ' winding can refer to Fig. 7.The connection of each coil of vice-side winding can refer to Fig. 6.The iron core of the utility model distribution transformer and other structure and common transformer are as good as.

The connection principle of D, zn connection distribution transformer is see Fig. 3, Fig. 4.In figure, W1 ~ W3 is umber of turn, and the calculating that former limit D connects winding is arranged to be as good as with common transformer with being connected.Vice-side winding number of turn W2 and W3 is determined by the θ angle selected, W1 and transformer transformation ratio.Other calculation of parameter of this transformer and common transformer are as good as, and its impedance occurrence can refer to harmonic spectrum and determines.The connection of each coil of vice-side winding can refer to Fig. 6.As shown in Figure 6, every phase winding is divided into 2 parts, is set on the core limb of three-phase iron core respectively successively; In figure, ax, by and cz are main winding, and y ' b ', z ' c ' and x ' a ' are Phase shift winding, and a ', b ' and c ' all meet neutral point o.

Claims (2)

1. a new distribution transformer, is characterized in that: described transformer primary side winding is that D ' type connects, or common D type connects; Transformer secondary winding is that zn type connects;

Described D ' type connects: former limit A, B and C three-phase windings is set with on three core limbs of three-phase iron core; B phase winding is with extension winding AD and EB; Extend winding AD and EB arranged crosswise on B phase iron core; A phase and C phase winding are with respectively and are extended winding α D and β E; Extending winding α D and β E is set with in A phase and C phase iron core; In three-phase windings, the end of a phase winding and the head end of another phase winding connect together, and connect into a closed-loop path in turn, are connected into triangle △ ABC; Wire is drawn from terminal α, β and C; Original edge voltage U α C and U β C differs 90 ° of electric angles; The equivalent impedance ratio of former limit A, B, C three-phase windings is: 1:Kz:1, Kz span is △ ABC winding phase voltage equals the number of turn of former limit A, B and C three-phase windings is w1; The number of turn that A phase extends winding α D and β E with C phase is W5, and the number of turn that B phase extends winding AD and EB is W4; Following relation is had between each umber of turn:

W4＝K4×W1

W5＝K5×W1；

$K4=\sqrt{3}/(Kz+2)$

$K5=(\sqrt{3}+1-Kz)/(Kz+2)$

Described common D type connects: former limit A, B and C three-phase windings is set with on three core limbs of three-phase iron core; In three-phase windings, the end of a phase winding and the head end of another phase winding connect together, and connect into a closed-loop path in turn, are connected into triangle △ ABC; Wire is drawn from terminal A, B and C; Former limit three-phase voltage differs 120 ° of electric angles; The number of turn of former limit A, B and C three-phase windings is w1;

Described zn type connects: the meander configuration wiring that neutral point is drawn; Comprise a, b and c three-phase windings, every phase winding is divided into 2 parts: main winding and Phase shift winding, is set on the core limb of three-phase iron core respectively successively; The end of one phase main winding and the end of another phase Phase shift winding connect together, and the head end of this another phase Phase shift winding meets neutral point o; Neutral point o ground connection; The number of turn of three-phase main winding is w2, and the number of turn of three-phase phase shifting winding is w3, w2 and w3 is determined by the θ angle selected, w1 and transformer transformation ratio.

2. new distribution transformer according to claim 1, is characterized in that: described phase shifting angle θ selects as required.