CN202422977U

CN202422977U - Balancing transformer for converting three-phase to two-phase

Info

Publication number: CN202422977U
Application number: CN2011205670815U
Authority: CN
Inventors: 吕维华; 杨宏伟
Original assignee: TIANWEI YUNNAN TRANSFORMER CO Ltd
Current assignee: TIANWEI YUNNAN TRANSFORMER CO Ltd
Priority date: 2011-12-30
Filing date: 2011-12-30
Publication date: 2012-09-05
Anticipated expiration: 2021-12-30

Abstract

The utility model provides a balancing transformer for converting three-phase to two-phase, which comprises an iron core, a primary-side three-phase winding and a secondary-side three-phase winding, wherein the primary-side three-phase winding comprises an A-phase winding, a B-phase winding and a C-phase winding in triangular connection; the A-phase winding, the B-phase winding and the C-phase winding are same in circle number; the primary-side three-phase winding comprises an a-phase winding, a b-phase winding and a c-phase winding which are in star-shaped connection; the a-phase winding and the c-phase winding are same in circle number; the circle number of the b-phase winding is times of the circle number of the a-phase winding or c-phase winding; a two-phase voltage is outputted by the secondary-side three-phase winding; a leading-out terminal of the a-phase winding and the leading-out terminal of the c-phase winding are respectively output head ends of the two-phase voltage; and the leading-out terminal of the b-phase winding is an output common end of the two-phase voltage. The balancing transformer for converting three-phase to two-phase has the advantages of simple structure, being free from impedance matching, simple design and structure, easiness in manufacturing, low cost, and capability of effectively reducing the influence of an electrified railway on an electric system.

Description

Three-phase to two phase balance transformer

Technical field

The utility model relates to transformer technology, relates in particular to a kind of three-phase to two phase balance transformer, belongs to the traction transformer technical field.

Background technology

Traction transformer is the transformation of electrical energy device that the outer power voltage that in the electric railway traction power supply system electric power system provided converts the required voltage of electric locomotive into.

Electric locomotive adopts the single phase alternating current power supply power supply, so traction transformer generally adopts single-phase transformer or three phase transformation two-phase dedicated transformers.Two single-phase transformer V-arrangements of general employing connect when adopting single-phase transformer, give the up-downgoing locomotive power supply of electric railway, and advantage is that the transformer manufacturing is simple, and the core material utilance is 100%.Shortcoming is that primary current and secondary current all are unbalanced systems, and the efficient of electric power system is merely 2/3.

Existing balance transformer for two phase changed from three-phase mainly contains YNV (YNA) balanced impedance matching transformer and Scott balancing transformer.

Former limit three phase windings of YNV (YNA) balanced impedance matching transformer are Y-connection, and neutral point can be drawn ground connection, and secondary has triangle to connect winding, can form the triple harmonic current loop, and magnetic flux and induction voltage waveform are good.But this balancing transformer needs impedance matching, thereby design and manufacturing difficulty.

The secondary side two-phase of Scott balancing transformer does not have the contact of electricity, does not therefore have circulation; But the master of Scott balancing transformer, that ladder becomes structure is different, thus design with complex structure, make difficulty, and do not have delta connection, can not form the triple harmonic current loop, magnetic flux and induction voltage waveform distortion, three-phase side pressure regulation inconvenience.

The utility model content

The utility model provides a kind of three-phase to two phase balance transformer, is used for solving design of prior art three-phase to two phase balance transformer and complex structure, makes the difficult technologies defective.

A kind of three-phase to two phase balance transformer that the utility model provides; Comprise iron core, former limit three phase windings and secondary three phase windings; Said former limit three phase windings comprise A phase winding, B phase winding and C phase winding; And for delta connection connects, the equal turn numbers of said A phase winding, B phase winding and C phase winding;

Said secondary three phase windings comprise a phase winding, b phase winding and c phase winding, and are the star connection connection; The equal turn numbers of said a phase winding and c phase winding, the number of turn of said b phase winding be said a phase winding or c phase winding the number of turn

doubly;

Said secondary three phase windings are exported two phase voltages; The exit of the exit of said a phase winding and c phase winding is respectively two phase voltages output head end, and the exit of said b phase winding is two a phase voltages output common port.

Preferably, said two phase voltages output head end is respectively applied for the traction net bus of traction substation both sides and is connected, and said two phase voltage common ports are used for being connected with track and ground network.

Preferably, said iron core is three phase three limb core or three phase five pole type iron core.

Preferably, the three-phase side of said three-phase to two phase balance transformer is non-excitation pressure adjustment or on-load voltage regulation.

The three-phase to two phase balance transformer that the utility model provides, because former limit three phase windings are delta connection, secondary three phase windings are star connection and select the specific number of turn, realize the balance of primary current and secondary current.The three-phase to two phase balance transformer that the utility model provides compared with prior art, need not to carry out impedance matching, and design and simple in structure, easy to manufacture and cost is low can effectively reduce the influence of electric railway to electric power system.

Description of drawings

The elementary diagram of the three-phase to two phase balance transformer that Fig. 1 provides for the utility model embodiment;

The voltage vector diagram of the three-phase to two phase balance transformer that Fig. 2 provides for the utility model embodiment;

The winding connection sketch map of the three-phase to two phase balance transformer that Fig. 3 provides for the utility model embodiment.

Reference numeral:

The 1-A phase winding; The 2-B phase winding; The 3-C phase winding;

The 4-a phase winding; The 5-b phase winding; The 6-c phase winding.

Embodiment

With reference to figure 1-3, the elementary diagram of the three-phase to two phase balance transformer that Fig. 1 provides for the utility model embodiment; The voltage vector diagram of the three-phase to two phase balance transformer that Fig. 2 provides for the utility model embodiment; The winding connection sketch map of the three-phase to two phase balance transformer that Fig. 3 provides for the utility model embodiment.

As shown in figs. 1 and 3, the three-phase to two phase balance transformer that present embodiment provides comprises (not shown) unshakable in one's determination, former limit three phase windings and secondary three phase windings.

Former limit three phase windings comprise A phase winding 1, B phase winding 2 and C phase winding 3, and for delta connection connects, just A phase winding 1, B phase winding 2 and C phase winding 3 are end to end; The equal turn numbers of A phase winding 1, B phase winding 2 and C phase winding 3.Particularly, the number of turn of A phase winding 1 is W _A, the number of turn of B phase winding 2 is W _B, the number of turn of C phase winding 1 is W _C, and W _A=W _B=W _C

The exit C of the exit A of A phase winding 1, the exit B of B phase winding 2 and C phase winding 3 is the input terminal of this three-phase to two phase balance transformer.

Secondary three phase windings comprise a phase winding 4, b phase winding 5 and c phase winding 6, and for star connection connects, just the end of a phase winding 4, b phase winding 5 and c phase winding 6 connects together.The number of turn of a phase winding 4 is W _a, the number of turn of b phase winding 5 is W _b, the number of turn of c phase winding 6 is W _c, and the equal turn numbers of a phase winding 4 and c phase winding 6, just W _a=W _c, the number of turn of b phase winding 5 is the number of turn of a phase winding 4 or c phase winding 6

Doubly, just

W_{b} = (\sqrt{3} - 1) / 2 W_{a}

= (\sqrt{3} - 1) / 2 W_{c} .

Secondary three phase windings are exported two phase voltages, are specially α phase voltage and β phase voltage; The exit a of a phase winding 4 and the exit c of c phase winding 5 are respectively the output head end of α phase voltage and β phase voltage, and the exit b of b phase winding 5 is the output common port of α phase voltage and β phase voltage.

Need to prove that when this three-phase to two phase balance transformer was the traction electric machine power supply of electric locomotive, two phase voltages output head end a, c received respectively on the traction net bus of traction substation both sides, two phase voltages output common port b is connected with track and ground network.

As shown in Figure 2; The exit A of former limit three phase windings, exit B and exit C insert the three-phase power electrical network; The input three-phase symmetric voltage; Then A is that

B is

equal and opposite in direction for C to the voltage of winding 3 to the voltage of winding 2 to the voltage of winding 1, phase difference 120 degree.Output α phase voltage be that to export the β phase voltage between exit c and the exit b of

secondary three phase windings be

and

equal and opposite in direction between the exit a of secondary three phase windings and exit b; Number of turn relation according to secondary three phase windings can be extrapolated, and

and

phase difference is 90 degree.

In the present embodiment, iron core is three phase three limb core or three phase five pole type iron core, can select the multi-form iron core and the position of winding according to actual needs.The three-phase side of three-phase to two phase balance transformer is non-excitation pressure adjustment or on-load voltage regulation, is convenient at the three-phase side regulation voltage.

In the practical application, former limit three phase windings are delta connection, and the third-harmonic component path can be provided, and magnetic flux and induction voltage waveform are good.

When this three-phase to two phase balance transformer secondary α and β two phase loads equated, primary current was the three-phase symmetric system, and no zero-sequence component does not have negative sequence component yet, can effectively reduce the influence of electric railway to electric power system.

Need to prove that if import two phase quadrature voltages at the exit of secondary three phase windings, then exit is exported three-phase symmetric voltage from former limit, this three-phase to two phase balance transformer also can be realized the function of two phase transformation three-phases.

The three-phase to two phase balance transformer that present embodiment provides, because former limit three phase windings are delta connection, secondary three phase windings are star connection and select the specific number of turn, realize the balance of former limit three-phase current.

The three-phase to two phase balance transformer that the utility model provides compared with prior art, need not to carry out impedance matching, and design and simple in structure, easy to manufacture and cost is low can effectively reduce the influence of electric railway to electric power system.

What should explain at last is: above each embodiment is only in order to the technical scheme of explanation the utility model, but not to its restriction; Although the utility model has been carried out detailed explanation with reference to aforementioned each embodiment; Those of ordinary skill in the art is to be understood that: it still can be made amendment to the technical scheme that aforementioned each embodiment put down in writing, perhaps to wherein part or all technical characteristic are equal to replacement; And these are revised or replacement, do not make the scope of each embodiment technical scheme of essence disengaging the utility model of relevant art scheme.

Claims

1. three-phase to two phase balance transformer; Comprise iron core, former limit three phase windings and secondary three phase windings; It is characterized in that; Said former limit three phase windings comprise A phase winding, B phase winding and C phase winding, and for delta connection connects, the equal turn numbers of said A phase winding, B phase winding and C phase winding;

doubly;

2. three-phase to two phase balance transformer according to claim 1 is characterized in that, said two phase voltages output head end is used for being connected with the traction net bus of traction substation both sides respectively, and said two phase voltage common ports are used for being connected with track and ground network.

3. three-phase to two phase balance transformer according to claim 1 and 2 is characterized in that, said iron core is three phase three limb core or three phase five pole type iron core.

4. three-phase to two phase balance transformer according to claim 3 is characterized in that, the three-phase side of said three-phase to two phase balance transformer is non-excitation pressure adjustment or on-load voltage regulation.