A kind of high-capacity three-phase composite type phase shifting transformer
Technical field
The present invention relates to a kind of phase shifting transformer, be specifically related to a kind of high-capacity three-phase composite type phase shifting transformer.
Background technology
Phase shifting transformer, by the phase difference between adjustment input and output voltage, makes power system operation stability and high efficiency more.The general principle of phase shifting transformer phase shift produces a voltage between mains side and load-side, this voltage and mains side voltage have certain phase angle difference, and effective value size can adjust, and be load side voltage with mains side voltage superposition, make between mains side and load side voltage, to produce phase place change.Phase shifting transformer conventional at present comprises holocentric formula and diplocardia formula two kinds of basic structures.The general principle of holocentric formula phase shifting transformer is connected with another a part for a phase voltage, therefore relatively simple for structure, but its voltage regulation coil is positioned at circuit head end, shunting switch electric pressure higher and the various overvoltage of directly bearing in operation of power networks and overcurrent, be not therefore suitable for voltage levels and Large Copacity condition.Two heart type structure by series transformer and excitation transformer dimerous, these two parts are contained in two independently on iron core, and are contained in two respectively independently in oil tank of transformer.Excitation transformer is often made up of pressure regulation magnet exciting coil and voltage regulation coil, and joint group is Y/Y, and pressure regulation magnet exciting coil provides excitation for excitation transformer, and each tap of voltage regulation coil is received on load tap changer, and on load tap changer is with positive and negative change over selector.Diplocardia formula phase shifting transformer and holocentric formula structure compared complexity, but its shunting switch electric pressure is lower, therefore the occasion of Large Copacity and voltage levels is applicable to, but connecting lead wire insulation level and line insulation are on close level in the syndeton between two fuel tanks of series transformer and excitation transformer, therefore syndeton more complicated, and the installation difficulty of two fuel tanks is also higher.
Summary of the invention
For the problems referred to above, the present invention proposes a kind of high-capacity three-phase composite type phase shifting transformer, the object that diplocardia formula phase shifting transformer reduces the electric pressure of shunting switch can be reached, the syndeton between each several part can be simplified again simultaneously, reduce technical difficulty, be applicable to more voltage levels and more jumbo occasion.
For solving the problem, the technical scheme that the present invention takes is: a kind of high-capacity three-phase composite type phase shifting transformer, comprise three single-phase transformers, respectively as A, B, C three-phase is combined into three-phase transformer, every platform single-phase transformer comprises series transformer and excitation transformer, both are placed in same fuel tank and are divided into two independently device body parts, the transformer that is often in series comprises series coil and magnet exciting coil, wherein the head end of series coil and end are respectively as mains side input terminal and load-side lead-out terminal, the head of magnet exciting coil, end all draws fuel tank, when three-phase runs jointly, the first joining distal ends of three-phase series coil is linked to be dihedral, the first joining distal ends of three phase excitation coil is linked to be dihedral, excitation transformer comprises pressure regulation magnet exciting coil and voltage regulation coil, the head end of pressure regulation magnet exciting coil is connected with the centre cap of series coil in the series transformer of homophase, end is that neutral point draws fuel tank, the head end of voltage regulation coil is drawn fuel tank and is connected with the dihedral node of all the other two-phase excitation coils, end draws fuel tank as neutral point, when three-phase runs jointly, three phase voltage regulating magnet exciting coil is Y-connection, and three phase voltage regulating coil is Y-connection.A, B, C three-phase is placed in three different fuel tanks by three phase combined phase shifting transformer respectively, size and the weight of single transformer can be reduced, be convenient to transport and install, therefore be applicable in more voltage levels and more under Large Copacity occasion, simultaneously the head end of pressure regulation magnet exciting coil is connected in same fuel tank with homophase series coil is centre tapped, does not need by special syndeton connected, also need not draw fuel tank, therefore structure herein simplifies greatly, reduces technical difficulty.Each line end is drawn by sleeve pipe, and between three-phase, the material such as available cable realizes being flexible coupling, and in-site installation operation, test and operation maintenance are also more easy.
All current limiting reactor is installed in the first and end of described series coil, for alleviating the impact of electrical network short circuit currents to phase shifting transformer.
Current limiting reactor is in series with in described voltage regulation coil.When phase shifting transformer capacity is larger, multiple series coil is adopted to connect, multiple magnet exciting coil is in parallel, multiple pressure regulation magnet exciting coil is in parallel, the structure of multiple voltage regulation coil series connection, because in voltage regulation coil, electric current is excessive, therefore adopts multiple stage on load tap changer, now seal in every bar voltage regulation coil branch road current limiting reactor for balancing branch in electric current distribute, and limit the damage that issuable short circuit current causes on load tap changer.
Structure of the present invention is simple, can reduce the electric pressure of shunting switch, also can simplify the syndeton between each device body, reduces installation difficulty, in the phase shifting transformer of Large Copacity and voltage levels, have stronger practicality.
Accompanying drawing explanation
Fig. 1 is the single-phase elementary diagram of embodiment one;
Fig. 2 is embodiment one elementary diagram;
Fig. 3 is phase-shift theory figure of the present invention;
Fig. 4 is the single-phase elementary diagram of embodiment two;
Fig. 5 is the single-phase elementary diagram of embodiment three;
In figure, 1, series transformer, 2, excitation transformer, SVA-SVC is respectively A phase, B phase, C are in series coil, SVA1, SVA2 are that A is in series two coils of coil, EVA-EVC is respectively A phase, B phase, C phase excitation coil, EVA1, EVA2 are two coils of A phase excitation coil, TVA-TVC is respectively A phase, B phase, C phase voltage regulation coil, TVA1, TVA2 are two coils of A phase voltage regulation coil, TEVA-TEVC is respectively A phase, B phase, C phase pressure regulation magnet exciting coil, and TEVA1, TEVA2 are two coils of A phase pressure regulation magnet exciting coil, L1-L2, reactor.
Embodiment
embodiment one
A kind of high-capacity three-phase composite type phase shifting transformer, comprise three single-phase transformers, be combined into three-phase transformer respectively as A, B, C three-phase, every platform single-phase transformer comprises series transformer 1 and excitation transformer 2, and both are placed in same fuel tank and are divided into two independently device body parts.As shown in Figure 1, for A phase, series transformer 1 comprises series coil SVA and magnet exciting coil EVA, draw four terminals: series coil head end SA and series coil end LA is respectively as mains side input terminal and load-side lead-out terminal, the head end sa of magnet exciting coil, magnet exciting coil end la all draws fuel tank, excitation transformer 2 comprises pressure regulation magnet exciting coil TEVA and voltage regulation coil TVA, the head end ta of pressure regulation magnet exciting coil is connected with the centre cap of series coil SVA in the series transformer 1 of homophase, end is that neutral point draws fuel tank, voltage regulation coil head end TA draws fuel tank, end draws fuel tank as neutral point.B phase, C phase are identical with A phase structure.As shown in Figure 2, when three-phase runs jointly, the first joining distal ends of three-phase series coil SVA-SVC is linked to be dihedral, and the first joining distal ends of three phase excitation coil EVA-EVC is linked to be dihedral; Three phase voltage regulating magnet exciting coil TEVA-TEVC is Y-connection, and three phase voltage regulating coil TVA-TVC is Y-connection.The first joining distal ends of magnet exciting coil EVA-EVC of three-phase is linked to be dihedral, the every two dihedral nodes be connected are connected with the voltage regulation coil head end of third phase, and adjust by load tap changer the number of turn that voltage regulation coil seals in circuit and change voltage swing in voltage regulation coil and polarity, phase-shift theory as shown in Figure 3, the iron core that this voltage is series transformer provides excitation, make the magnet exciting coil of corner connection in series transformer produces one advanced or lag behind the voltage of pressure regulation magnet exciting coil voltage 90 ° of homophase excitation transformer.This voltage responds in corresponding series coil that to produce with homophase pressure regulation magnet exciting coil phase difference be the voltage Δ U of 90 °
1with Δ U
2, these two voltages make the mains side voltage U of phase shifting transformer
sAwith load side voltage U
lAbetween produce the change of a phase angle, and output voltage size is identical with input voltage size, realizes the change of phase angle between mains side and load side voltage, by the position of regulation tap switch, realize this phase difference size and advanced or delayed between adjustment.
embodiment two
A kind of high-capacity three-phase composite type phase shifting transformer, as shown in Figure 4, all be provided with for alleviating electrical network short circuit currents current limiting reactor L1, L2 to the impact of phase shifting transformer at described series coil head end SA and series coil end LA, other structures are identical with embodiment one.
embodiment three
A kind of high-capacity three-phase composite type phase shifting transformer, as shown in Figure 5, because phase shifting transformer capacity is larger, adopt two series coil SVA1, SVA2 connects, two magnet exciting coil EVA1, EVA2 is in parallel, two pressure regulation magnet exciting coil TEVA1, TEVA2 is in parallel, two voltage regulation coil TVA1, the structure of TVA2 series connection, because in voltage regulation coil, electric current is excessive, therefore three on load tap changeres are adopted, seal in three branch roads and distribute for balancing electric current in three branch roads and limit the current limiting reactor L1 of issuable short circuit current to the damage that on load tap changer causes, L2, other structures are identical with embodiment one.