CN2428848Y - Three-phase to four-phase electric transformer - Google Patents

Abstract

The utility model relates to a three-phase to four-phase electric transformer, which is formed by winding a first and a secondary primary windings 5, 6 of an a-phase column, a first and a secondary primary windings 7, 8 of a c-phase column, a first and a secondary primary windings 11, 12 of a d-phase column, and four-phase side windings 13, 14, 15, 16 on a uniform section four-column type iron core. The utility model is characterized in that the winding 5 is connected in parallel with the winding 7 in an opposite phase mode, forming a three-phase side A phase; the winding 6 is connected in parallel connection with the winding 8 in an opposite phase mode, forming a common branch of three-phase side B and C phases; the winding 9 and the winding 11 which are connected with each other by parallel connection in an opposite phase mode are connected in series with the common branch, forming a three-phase side c phase; the winding 10 and the winding 12 which are connected with each other by parallel connection in an opposite phase mode are connected in series with the common branch, forming a three-phase side c phase; the three-phase side A, B, C phases are provided with a common earthing contact; the windings 13, 14, 15, 16 respectively form the four-phase side a, c, b, d phases. The utility model is mainly used for realizing four-phase AC transmission of high-voltage power network, and can also be used as a traction power supply transformer of the power supply mode of electrified railways AT.

Description

Power transformer changing triphase into four-phase

The utility model relates to a kind of power transformer, and particularly a kind of three-phase electrical power system with symmetry is transformed to voltage each other 90.Four phase systems of electrical degree or carry out the power transformer changing triphase into four-phase of inverse transformation.

At present, AC transmission system adopts three-phase system usually both at home and abroad.Because generator and motor in the electric power system all adopt three-phase system, three-phase power transformer manufactures and designs simple and convenient, and the three-phase system transmission of electricity has become traditional power transmission mode.But in three phase line, voltage between phase and phase is the voltage between the phase and ground $\sqrt{3}$ Doubly, air insulation between the three-phase conducting wire is had relatively high expectations, make the spacing broad that three-phase conducting wire is arranged, the shared land area in waste stringing corridor, it is bigger to take up an area of reimbursement for expenses.Because three-phase conducting wire can not be suspended on the both sides of single-column shaft tower symmetrically, make that the shaft tower design is complicated, and waste shaft tower steel.Abroad, the research of 6 phases, 9 phases, 12 phases, 24 equal heterogeneous transmission systems was carried out for two more than ten years.Heterogeneous transmission of electricity is a kind of important method that improves transmission power density.The phase number average of existing heterogeneous transmission system is 3 integral multiple, realize three-phase and heterogeneous between the power transformer of conversion easily manufactured.But, transposition for fear of heterogeneous transmission line complexity, each phase conductor must be arranged in regular polygon, this makes 6 suspensions that reach above heterogeneous lead mutually difficulty more, tower structure is complicated more, the circuit cost rises: along with the increase of the circuit number of phases, the fault composite type of heterogeneous transmission line increases sharply, and this makes the design of faults analysis calculating, relaying protection and adjusts has increased difficulty; Breaker structure more complicated in the heterogeneous transmission system, alternate overvoltage multiple is higher.Because above-mentioned shortcoming, six reach above heterogeneous power transmission mode is not mutually applied.

Four phase transmission systems are to approach the polyphase system of traditional three-phase most, and it had both had the advantage of heterogeneous power transmission mode, have overcome the shortcoming that heterogeneous power transmission mode exists again.Realize that the four great key equipments of transmitting electricity out mutually are four phase transformation three-phase power transformers of three crossing four phase power transformers and inverse transformation.Intersect on the basis of biphase equilibrium transformer in the three flat transformers of phase transformation two-phase balanced impedance matching and Y/＞/one wiring three that China proposes, employing increases the connection plan of a cover and original identical auxiliary winding in the two-phase side, can constitute three crossing four phase power transformers.But,, make these two kinds of design of transformer be difficult to reach the requirement of each phase parameter balance when making because the winding number is more on every phase iron core column.Because four phase side windings are tortuous connections, make that four phase side winding numbers of these two kinds of transformers are more, being not suitable for four phase sides is on high-tension side four phase transmission systems, and for example the high-pressure side winding can not be with the tap pressure regulation, high-pressure side winding insulation complex structure increases and makes production cost.Do not see at present and produce family's development power transformer changing triphase into four-phase.

At the above-mentioned defective that prior art exists, the purpose of this utility model is that a kind of power transformer changing triphase into four-phase that mainly is applicable to four phase transmission systems is provided, and makes that simultaneously it is simple in structure, low cost of manufacture, iron core and winding material utilance height.

Solution of the present utility model is as follows.Its feature part is to have prismatic four phase iron core column 1,2,3,4.A and c iron core column 1 and 2 mutually are arranged in a side, and b and c core limb 3 and 4 mutually are arranged in opposite side, and middle two iron yokes up and down both can keep, and also can save.Three-phase side has umber of turn and is respectively W _A1And W _A2A phase post first primary winding 5 and a post second primary winding 6 mutually, umber of turn is respectively W _C1And W _C2C phase post first primary winding 7 and c post second primary winding 8 mutually, umber of turn is respectively W _B1And W _B2B phase post first primary winding 9 and b post second primary winding 10 mutually, umber of turn is respectively W _D1And W _D2D phase post first primary winding 11 and d mutually post second primary winding 12, four phase sides have umber of turn and be respectively W _A3, W _C3, W _B3, W _D3A, c, b, d phase post auxiliary winding 13,14,15,16; Winding 5,6,13 is wound on the iron core column 1, winding 7,8,14 is wound on the iron core column 2, winding 9,10,15 is wound on the iron core column 3, winding 11,12,16 is wound on the iron core column 4, winding symmetry on winding on the iron core column 1 and the iron core column 2, the winding symmetry on winding on the iron core column 3 and the iron core column 4; Winding 5 constitutes three-phase side A mutually with 7 parallel connected in reverse phase, winding 6 constitutes three-phase side B, C common branch mutually with 8 parallel connected in reverse phase, series connection constitutes three-phase side B mutually to winding 9 with common branch again with 11 parallel connected in reverse phase, series connection constitutes three-phase side C mutually to winding 10 with common branch again with 12 parallel connected in reverse phase, and three-phase side A, B, C have common ground point O mutually; Winding 13,14,15,16 constitutes four phase side a, c, b, d phase respectively.

Apparatus of the present invention with said structure, its core section select then that principle, winding are arranged, all with generally power transformer is identical for winding wire diameter selection principle and impedance computation method.The electromagnetic capacity of its a, b, c, d four phases equates, each self-balancing of number of ampere turns.Each phase iron core column is selected core section by the maximum magnetic flux density that allows.The high pressure winding technique is at skin, and the low pressure winding technique is at internal layer.Each winding is selected conductor cross-section by economic current density and moving, thermally-stabilised requirement, the equivalent impedance of each winding calculates by multi winding transformer impedance computation method, by each winding reasonable Arrangement, when accomplishing the mutual short circuit of four phase side exits, A, B, the C phase short-circuit impedance seen into from three-phase side equate.

The utility model device is made step-up transformer mutually and is made step-down transformer with four phase transformation three-phases with three phase transformations four, mainly is used as the great key equipment that high-tension network is realized four-phase AC transmission.And, then can be used as the traction power supply transformer of electric railway AT (autotransformer) supply power mode with three phase transformations, four phase step-down transformers.

Below in conjunction with drawings and Examples the utility model is further specified.

Fig. 1 is the core structure schematic diagram of the utility model device.

Fig. 2 is the elementary diagram that four phase sides adopt the utility model device of Y-connection.

Fig. 3 is the elementary diagram that four phase sides adopt the utility model device of quadrangle connection.

Referring to Fig. 1, four phase iron core column sectional areas equate, a phase iron core column 1 and c iron core column 2 mutually are arranged in one side, and b phase iron core column 3 and d iron core column 4 mutually are arranged in another side.When manufacturing and designing, middle two iron yokes up and down both can keep, and also can cancel, and did not influence the normal operation of transformer.

Referring to Fig. 2, four phase sides adopt Y-connection.The selection principle of each umber of turn of transformer of this mode of connection is: W _A1: W _A3=K ₁, W _A2=W _A1/ 2, W _B1=W _B2= $\sqrt{3}{W}_{a1}/2,$ W _a1=W _c1，W _a2=W _c2，W _b1=W _b2=W _d1=W _d2，W _a3=W _b3=W _c3=W _d3。K in the formula ₁Three-phase side phase voltage that provides for known conditions and four ratios of side phase voltage mutually.Its mode of connection has guaranteed at three-phase side input three-phase symmetric voltage  _A,  _B,  _CThe time, four phase voltage  of four phase sides output _a,  _b,  _c,  _dEqual and opposite in direction, the phase place 90 ° of electrical degrees that lag behind successively.When four phase side payload are identical with character, four phase current I of output _a, I _b, I _c, I _dEqual and opposite in direction, the phase place 90 ° of electrical degrees that lag behind successively.The three-phase side electric current with four mutually the matrix equation of side electric current be:

Following formula meets the principle of power transformer current matrix symmetry transformation, and during three-phase side electric current symmetry, four phase side electric currents are symmetry also.

Referring to Fig. 3, four phase sides adopt quadrangle to connect.The selection principle of each umber of turn of transformer of this mode of connection is: $W_{a1}:W_{a3}=K_2/\sqrt{2},$ W _a2=W _a1／2，W _b1=W _b2= $\sqrt{3}{W}_{a1}/2,$ W _a1=W _c1，W _a2=W _c2，W _b1=W _b2=W _d1=W _d2，W _a3=W _b3=W _c3=W _d3。K in the formula ₂Three-phase side phase voltage that provides for known conditions and four ratios of side phase voltage mutually.Its mode of connection has guaranteed at three-phase side input three-phase symmetric voltage  _A,  _B,  _CThe time, four phase voltage  of four phase sides output _a,  _b,  _c,  _dEqual and opposite in direction, the phase place 90 ° of electrical degrees that lag behind successively.When four phase side payload are identical with character, the electricity four phase current I of output _a, I _b, I _c, I _dEqual and opposite in direction, the phase place 90 ° of electrical degrees that lag behind successively.The three-phase side electric current with four mutually the matrix equation of side electric current be:

Following formula meets the principle of power transformer current matrix symmetry transformation, and during three-phase side electric current symmetry, four phase side electric currents are symmetry also.

The utility model device is applicable to that mainly high-tension network realizes four-phase AC transmission, in four-phase AC transmission system as great key equipment.The characteristics of these two kinds of mode of connection transformers are: four each phase winding of phase side are not tortuous the connections, being particularly suitable for four phase sides is on high-tension side four phase transmission systems, the tap pressure regulation can be with in the high-pressure side, high-pressure side winding minimum number, and be arranged on the different iron core column, make insulation simple, save the insulation costs and the shared space of insulating; Being three winding constructions on every phase iron core column, is the simple form that does not wait phase inversion, and the impedance matching relation of winding is met easily; Compound material utilance height not only can be saved manufacturing cost, can also reduce operating cost; Core structure is simple, and can be separated into two independent parts, has simplified manufacturing process, is particularly suitable for the manufacturing of large-capacity power transformer.

Power transformer changing triphase into four-phase of the present utility model also can be used for the tractive power supply system of electric railway as the traction power supply transformer, both has been applicable to the AT electric power system, also is applicable to the BT electric power system.

Claims (3)

1. power transformer changing triphase into four-phase is characterized in that:

(A) have prismatic four phase iron core column a (1), c (2), b (3), d (4);

(B) three-phase side has umber of turn and is respectively W _A1And W _A2A phase post first primary winding (5) and a post second primary winding (6) mutually, umber of turn is W respectively _C1And W _C2C phase post first primary winding (7) and c post second primary winding (8) mutually, umber of turn is respectively W _B1And W _B2B phase post first primary winding (9) and b post second primary winding (10) mutually, umber of turn is respectively W _D1And W _D2D phase post first primary winding (11) and d post second primary winding (12) mutually.Four phase sides have umber of turn and are respectively W _A1, W _C1, W _B1, W _D1A phase post auxiliary winding (13), c phase post auxiliary winding (14), b phase post auxiliary winding (15), d phase post auxiliary winding (16).Winding (5), (6), (13) are wound on the iron core column (1), and winding (7), (8), (14) symmetry are wound on the iron core column (2); Winding (9), (10), (15) are wound on the iron core column (3), and winding (11), (12), (16) symmetry are wound on the iron core column (4);

(C) winding (5) constitutes three-phase side A mutually with (7) parallel connected in reverse phase, winding (6) constitute with (8) parallel connected in reverse phase three-phase side B mutually with C common branch mutually, winding (9) constitutes three-phase side B mutually with the common branch series connection again with (11) parallel connected in reverse phase, and winding (10) constitutes three-phase side C mutually with the common branch series connection again with (12) parallel connected in reverse phase.Winding (13), (14), (15), (16) constitute four phase side a, c, b, d phase respectively;

(D) three-phase side winding A, B, C have common ground point mutually.

2. according to the described transformer of claim 1, four phase sides adopt Y-connection, and the selection principle of each umber of turn is W _A1: W _A3=K ₁, W _A2=W _A1/ 2, W _B1=W _B2= $\sqrt{3}{W}_{a1}/2$ , W _A1=W _C1, W _A2=W _C2, W _B1=W _B2=W _D1=W _D2, W _A3=W _B3=W _C3=W _D3, K in the formula _lThree-phase side phase voltage that provides for known conditions and four ratios of side phase voltage mutually.

3. according to the described transformer of claim 1, four phase sides adopt quadrangle to connect, and the choosing of each umber of turn was originally $W_{a1}:W_{a3}=K_2/\sqrt{2},$ W _a2=W _a1／2，W _b1=W _b2= $\sqrt{3}{W}_{a1}/2,$ W _A1=W _C1, W _A2=W _C2, W _B1=W _B2=W _D1=W _D2, W _A3=W _B3=W _C3=W _D3, K in the formula ₂Three-phase side phase voltage that provides for known conditions and four ratios of side phase voltage mutually.

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