CN2463938Y - Three-phase-two-phase balance phasing transformer - Google Patents

Abstract

The utility model relates to a three-phase and two-phase balance phase changing transformer. The utility model has the wire connection mode that three coils with the same turn on a three-phase side are connected into star shape (YN) or a triangle (D); three coils with the same turn in a two-phase side are connected into a triangle (d) on which an extending coil is added to form a star connection wire (d'). An iron core is in common structure of a three post type, a four post type or a five post type. The utility model has the same designing difficulty and the same art complexity with common power transformers. The utility model is suitable for a power supply system for converting three phases into two phases (such as a rail traction power supply system) and inversion from two phases to three phases.

Description

The covert transformer of three-phase-biphase equilibrium

The utility model is the three phase and symmetric power system that voltage magnitude equates, phase difference is 120 ° of electrical degrees to be transformed to voltage magnitude equates, phase difference is the covert transformer of the two-phase electric power system of 120 ° of electrical degrees, to satisfy the needs of two-phase Alternating Current Power Supply; Also the two-phase electric power system that voltage magnitude equates, phase difference is 90 ° of electrical degrees can be transformed to three phase and symmetric power system.When each output arm load amplitude equates, when character is identical, can keep the symmetry of input side electrical network constant.

The utility model is the invention of the new mode of connection of the covert transformer of three-phase-biphase equilibrium and winding configuration.

The alternating current traction power supply of railway and mine adopts two-phase or single phase power supply more, and the electric power system electrical network mostly is the three-phase symmetrical system.If from symmetrical three-phase electrical power system, take two-phase or single phase poaer supply by force, will cause the symmetry of three-phase electrical power system to be destroyed, will be in when operation to anti-negative phase-sequence and the zero-sequence current of sending of electrical network, this brings for the safe operation of electric power system and economy and has a strong impact on.The transformer that adopts three-phase equilibrium to become two-phase can alleviate or eliminate the harmful effect of negative phase-sequence or zero sequence widely.At present, widely used three phase transformation two-phase transformers have Scott, Leblanc, Woodbridge (and distortion) and K ü bler, (YN both at home and abroad, V, d) etc., now various mode of connection principal characters and the utility model feature list are analyzed as follows: existing operation technique and the utility model performance characteristic comparison sheet

As can be seen from the above table, the utility model three-phase side has the big electric current earth point of the desired satisfied neutral point of high-voltage power system, can reduce high pressure winding insulation level like this; The two-phase side also has-and common point can be for earthy, is specially adapted to rail traction BT supply power mode (the BT power supply unit is simple, voltage levvl is low, economical operation); It is low to manufacture and design difficulty; Coil quantity is few, has reduced the empty road of coil insulation, and does not need artificially to increase empty track pitch from, product actual volume minimum because of impedance matching; Transformer theoretical construct capacity also is minimum except that Scott, K ü bler.

In addition, during owing to the single armed asymmetric operation, the conductor cross-section that participates in operation is all big than other mode of connection, has reduced the load loss under this operating mode, can reduce transformer operating cost.Therefore the utility model is the invention that has very much social value.

Fig. 1 a) in, three numbers of turn are W ₁Coil be connected into star, neutral point can be drawn ground connection, constitutes the traction transformer of cross connection with threephase YN connection.When three-phase side voltage≤60kV, three coils can also be connected into triangle, as Fig. 4.Three head ends of three-phase side winding are named as A, B, C terminal respectively, insert three phase and symmetric power system A phase, B phase, C phase respectively.

Fig. 1 b) in, the number of turn of the every sideline of triangle circle is W ₂, the coil that wherein has the tap limit can be made into a band tapped coil, also can make the number of turn and be

Times W ₂With

Times w ₂Two coils be in series.The number of turn of extension edge is w ₃Be connected on the coil tap on triangle tap limit, form " " wiring (being d ').Two-phase side output port is made of extension edge head end and common point, summit of triangle and common point, is named as β and α port respectively, two-phase side output port voltage  _{α c}And  _{β c}Amplitude equates that phase difference is 90 ° of electrical degrees.

The contact of electricity has a common edge between output port α and β, and like this, when two-phase side load current symmetry, the transformer three-phase side does not have negative phase-sequence, non-zero-sequence current produces; When two-phase side load current was asymmetric, transformer three-phase side negative-sequence current was also little than other mode of connection, and zero-sequence current is zero.

The outfit of each coil turn: among Fig. 1, make k ₁₂=w ₁/ w ₂, and w ₁=w ₂=1, then have

Promptly When two-phase side load current symmetry (is that α output port electric current is

β output port electric current is ) time, each branch current matrix is: each branch road of two-phase lateral coil: $\left[\begin{array}{c}{\stackrel{\·}{I}}_{\mathrm{ac}}\\ {\stackrel{\·}{I}}_{\mathrm{ba}}={\stackrel{\·}{I}}_{\mathrm{eb}}\\ {\stackrel{\·}{I}}_{\mathrm{ce}}\\ {\stackrel{\·}{I}}_{\mathrm{\βe}}\end{array}\right]=\left[\begin{array}{cc}\frac{2}{3}& 0\\ -\frac{1}{3}& 0\\ -\frac{1}{3}& -1\\ 0& -1\end{array}\right]\left[\begin{array}{c}\stackrel{\·}{I}\\ -j\stackrel{\·}{I}\end{array}\right]$ Each branch road of three-phase side coil: $\left[\begin{array}{c}{\stackrel{\·}{I}}_A\\ {\stackrel{\·}{I}}_B\\ {\stackrel{\·}{I}}_C\end{array}\right]=\frac{1}{k_{12}}\left[\begin{array}{cc}\frac{2}{3}& 0\\ -\frac{1}{3}& \frac{\sqrt{3}}{3}\\ (-\frac{\sqrt{3}}{9})-\frac{3-\sqrt{3}}{9}& -\frac{\sqrt{3}}{3}\end{array}\right]\left[\begin{array}{c}\stackrel{\·}{I}\\ -j\stackrel{\·}{I}\end{array}\right]$

Three-phase side and two-phase side voltage vector diagram are as shown in Figure 2.Three-phase side joint three phase and symmetric power system, voltage vector are that amplitude equates, phase difference is 120 ° of electrical degrees; Two-phase side  _α= _Ac=- _Ba- _Cb,

The magnetic potential balance vectogram is as shown in Figure 3: ${\stackrel{\·}{F}}_A=\frac{2}{3}\stackrel{\·}{I}{W}_2$

Obvious three-phase side three-phase magnetic potential amplitude equates, phase difference is 120 ° of electrical degrees, and by the ampere-turn equilibrium principle as can be known, the three-phase side electric current is that amplitude equates, phase difference is the forward-order current of 120 ° of electrical degrees, has therefore realized three-phase---the balanced transformation of two-phase.Fig. 5 is a two-phase side joint line chart During mirror transformation, Dui Ying three-phase side phase sequence figure with it.

Fig. 6 is the applicating example of the utility model in railway traction power supply system.Transformer three-phase side voltage is 110kV, and two-phase side output voltage is 27.5kV.The three-phase side terminal connects A, B, the c phase of three phase and symmetric power system; Two-phase side common point connects railroad track, and terminal α, β connect left lateral, right lateral traction power supply contact line respectively.Loc is electric locomotive among the figure, and Feeder is a feeder line, and IP is a phase splitter, and GT is a railroad track, and ocs is a contact line, and BT is a drain transformer.

Fig. 7 is that the utility model is the applicating example of three-phase electrical power system with two-phase electric power system inversion, and transformer two-phase side α terminal and c terminal connect two-phase power network α arm, and voltage is  _α, β terminal and c connect two-phase power network β arm, and voltage is  _β, voltage magnitude equates to be 27.5kV,  _αThe leading  of phase place _β90 ° of electrical degrees; Three coils of three-phase side are connected into star, form the three-phase four-wire system distribution network, and line voltage is 380V, and phase voltage is 220V.Three-phase can be respectively to 0 tape according to load, also can three facies tract threephase motors, Light is an illuminating lamp among the figure, Motor is a motor.

Claims (3)

1, a kind of YN or D, the three-phase of d ' wiring---the covert transformer of biphase equilibrium realizes that three phase and symmetric power system becomes the conversion of two-phase quantity of electricity of electric system evenly, it is characterized in that three-phase side is three and waits the circle coil attachment to become star YN or triangle D connection; The two-phase side joint becomes

Be d ' wiring, form winding diagram by 4 coils Make mirror transformation, also can find corresponding with it three-phase side phase sequence, the two-phase side has a public output point c, the triangular apex of adjoining with common point constitutes an output port, another output port is made of extension edge head end and common point, and two output port voltage vector amplitudes equate that phase difference is 90 ° of electrical degrees, each limit equal turn numbers of triangle, coil tap position to the first and last end turn number that has the tap limit is respectively

Times limit number of turn and

Times limit number of turn, this two parts number of turn also can separately turn to two absolute coils, tap with extend tail end and be connected, the number of turn of extension edge coil equals the triangle edges number of turn

Doubly, transformer core is common three pillar type or four-column type or pentastyle structure.

2, YN according to claim 1 or D, d ' wiring three-phase---the covert transformer of biphase equilibrium is characterized by: the impedance of each coil of three-phase side is equipped with by equivalent; Two-phase side triangle coil impedance is equipped with by equivalent, and the extension edge coil impedance is equipped with at random; Every iron core column impedance is promptly converted to the every phase of impedance of three-phase side and is equipped with by equivalence; The winding wire cross section is equipped with by each branch current effective value.

3, YN according to claim 1 or D, d ' wiring three-phase---the covert transformer of biphase equilibrium can realize that also voltage magnitude equates that phase difference is 90.The two-phase electric power system of electrical degree becomes voltage magnitude and equates that phase difference is the electrical transformation of the three phase and symmetric power system of 120 ° of electrical degrees.

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