Z'ednannya in trikutnik three-phase generator or the secondary winding of the transformer

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Crim z'ednannya with a star, generators of chi spozhivach three phase struma can be turned on with a tricoutnik.

On fig. 187 shows an unconnected three-phase system. Combining in pairs the wires of an unconnected six-wire system and the connecting phase, we can go to a three-phase three-wire system, connected by a tri-coil.

As can be seen from Fig. 188; linear darts.

As the windings of the generator are connected with a tricotnik, then, as can be seen from Fig. 188 line voltage is created by the skin phase winding. At the spozhivacha, connected with a tricot, the line voltage is connected to the phase support. Otzhe, when z'ednanny trikutnik phase voltage one line:

Significantly, the fallow between phases and linear strumas is significant when the tricot is connected, so the phases will be the same for the magnitude and nature. We store equal strums

It can be seen that the linear streams are complementary to the geometric difference of the phase streams. In case of equal phase shifting, the jet is the same for the value of i zsnuti one more by 120 °. Virobloyayuschie vіdnіmannya vіdnіmannya vіdnіynіnі strumіv zgіdno z otrimanimi іnіnannyami, otrimuєmo іnіyіnі strumi (Fig. 189). The fallows between phasic and linear streams at the planting of tricuts are shown in fig. 190.

On fig. 191 is given a vector diagram of strums and voltages with equal active inductive stress, connected by a tricout. Pobudova to go through the diagrams like this. At the chosen scale, there will be a equal-sided tricot of linear voltages U AB, U BC and U AC: as equal to the phase voltages of the support. At the bіk vіdstavannya pіd kutami to the line voltages U AB , U BC , i U CA will be on the scale of the phase stream vectors I AB , I BC , i I CA

Butt 2. Linear voltage, which is brought to a three-phase electric motor, up to 220 st. The winding of the motor may be the latest opir, which is 10 ohm. Designate strumi in linear darts and in the winding of the dvigun, as if the rest was tied with a tricot (Fig. 192, a).

For Ohm's Law

Oskіlki with z'ednannі trikutnik U L \u003d U f, then

The insulation of the phase of the motor is protected by a voltage of 220, and the phase winding is cut by heating for a stream of 22 a.

When connected with a tricot = 22-1.73 = 38 a.

The same motor can be switched on to a line voltage of 380 by switching the windings of the motor with a star (Fig. 192, b).

In motors and other spares of a three-phase struma of a local name, it is necessary to use six windings of three windings; Sound up to the three-phase machine, the board is creeping. insulation material(klemna doshka), on the yak i bring up the mustache of the shіst kіntsіv.

On fig. 193 shows a diagram of the connection of contacts on the terminal board to the ends of the windings of a three-phase machine. Mid jumpers allow you to easily change the scheme of switching on the windings.

If we have a dvigun, on the passport of which it is written 127/220 st, it means that this dvigun can be driven to two voltages: 127 and 220 st.

If the line voltage is more than 127, then the windings of the motor must be turned on with a tricout (Fig. 193, b). Then the winding of the phase of the motor is falling under the voltage of 127 st. At a voltage of 220, the motor windings must be turned on with a star (Fig. 193, a), then the phase winding will also be under a voltage of 127 V.

As soon as the skin phase of the winding of the generator ends with an ear of the offensive phase, the tricutnik is closed. Three linear rods are connected to the connecting points of the windings, which lead to the beginning. On the Rice. 7.3 a triphasic lancet is depicted, with a tricutnik. As can be seen from Fig. 7.3, in a three-phase lancet, connected with a tricot, the phases and linear voltages are the same.

U l = U f

I A, I B, I C - linear strumi;

I ab, I bc, I ca - phase struma.

Linear and phasic streams of vanity are related to each other by Kirchhoff's first law for knots a, b, c.

Linear strum is more expensive geometrical difference in phase strums.

The left and right parts of the equal system, (3.20), are taken

İa + ib + ic = 0,

tobto. sum of complexes line streams equal to zero if symmetrical, so i if not more symmetrical.

On fig. 7.4 shows a vector diagram of a three-phase lancet, connected with a tricot with a symmetrical entanglement. Expense є symmetrical so the phases are the same. The vectors of the phase streams run directly from the vectors of the current phase voltages, the voltage spikes are formed from the active supports.

With symmetrical vanishing

Z ab= Z bc = Z ca= Z e jφ ,

tobto. Z ab = Z bc = Z ca = Z, φ ab = φ bc = φ ca = φ.

Since the linear (stink and phase) voltages U AB, U BC, U CA are symmetrical, then the phase streams establish a symmetrical system

İab = Úab/Zab; İbc = Úbc/Zbc; İca = Úca/Zca.

The absolute values of them increase, and the destruction in phase is equal to 120°.

Linear streams

İa = İab - İca; ib = İbc – İab; ic = İca – İbc;

satisfy the same symmetrical system strumiv (Fig.3.13, 3.14).

On the vector diagram (Fig. 3.14), the phase jets show the phase voltage on the coil φ (note that the phases are inductive, so φ > 0°). Here it is accepted that the voltage UAB has a zero phase. From the diagrams it is clear that there could be a linear strum larger than a phase one at a time. Linear strum A is in phase with the phase strum ab at the corner of 30 °, at the same corner it is B in Bc, C in İ ca .

In such a rank, when z'ednanny trikutnik, the rank of meaning line strum with symmetrical vanishing times more dignified phase strumuta U L = U F; I L \u003d I F.

In case of equal phase advancement, the development of a three-phase lancet lancet with a tricot can be brought up to a development of one phase.

Phase voltage U Ф \u003d U L. Phase stream I Ф \u003d U Ф / Z Ф, linear stream I L \u003d I Ф, cut zsuvu in phase φ \u003d arctg (X Ф / R Ф).

From the vector diagrams it can be seen that

I l = √3 I f with symmetrical vanishing.

Triphasic lancets, with a starry, naboule of a larger width, lower triphasic lancers, with a tricot. This is explained by the fact that, first, in a lance, with a star, you can take two voltages: a linear one and a phase. In another way, as the phases of the winding of an electric machine, connected by a tricotnik, are known in different minds, in the windings there are additional streams that they are navantazhuyut. Such streams are present at the phases of an electric machine, connected behind the "star" circuit. Therefore, it is practical to uniquely close the windings of three-phase electrical machines in trikutnik.

In a steep slope with asymmetric vanishing Z ab ≠ Z bc ≠ Z ca. Sound out the blame for the hour of life in a three-phase line of single-phase priymachiv. For example, for the purpose, fig. 3.15, the phases of strumi, kuti zsuvu phases and phasic tension will be different in the wild phase.

Vector diagram for vipadku, if phase ab є more active, In the bc phase it is active-inductive, and in the ca phase it is actively-dismissive induced in fig. 3.16 topographic diagram - in fig. 3.17.

Pobudov’s vectors

Here we go x windings ax on the cob b windings by, end y windings by on the cob c windings cz, end z windings cz on the cob a windings ax so, as shown in the little one 1. So it looks like a guessing tricutnik, stars and resemble a yoga name. Linear darts are attached at the tops of the trikutnik.

Figure 1

Main spivvіdnoshennia:
1. When connecting the linear and phase voltages to the tricoutnik, the voltages are equal to those that the skin two (as you can see from the little one 1) come to the cob and end of one of the phase windings, and all the phase windings are the same.
2. Linear streams I l more phase I f y √3 = 1.73 times.

Yak to bring sho I l = 1.73 × I f? Whose baby is speeding 2.

Figure 2

Phasing strumi I ab I bc, I ca at three electric receivers EP(Malyunok 2, but) are depicted by a vector diagram (Figure 2, b); but. Peaks trikutnika navantagen a, bі cє nodal points. For this, fair equivalence

I a + I ca= I ab , stars I a = I ab- I ca;
I b+ I ab= I bc , stars I b= I bc- I ab;
I c+ I bc = I ca , stars I c= I ca- I b.c.

It dawned on me that equanimity geometric For this, it is necessary to follow the rules of the vector review, which is broken down to little 2, b. Bezperednіy vimir dovzhin vektorіv or calculation for the rules of geometry show what linear streams I a, I b i I with more phase jets I ab I bc i I ca y √3 = 1.73 times.

On the little one 2, b it can also be seen that the vector diagram of symmetrical linear streams I a, I b i I c zsunuta 30 ° ubik, return vector wrapping with phase stream diagrams. I ab I bc i I ca. In other words, strum I a extends 30° to the stream I ab. Strum I b extends 30° to the stream I bc, strum I from 30° to the stream I ca.
The order of the indexes of the identified phase streams is to indicate the order. In our butt, the order of the sequence (wrap) of phases: a, b, c.

On the little one 2, in shown generator windings or second. Vectors strumiv I ba, I ac, I cb , which passes in the windings of the generator (secondary windings of the transformer), and I ab I ca, I bc) appear to be parallel, but rotated 180°. The reason for such a roztashuvannya is a vector in the camp of understanding, as if to eat little ones 2, in with the right part of the baby 2, but scho vikonano on baby 2, G.

There is respect that all three windings in the middle generator (transformer) z'єdnani poslіdovno that utvoryuyut closures lansyug. A similar order in the settings brought up to . In three-phase strum installations, through those electrical disruption forces(e. f. s.) zsnutі 120 °, strum at the same closed circuit per day, so that the moment of the sum of e. f. s. three windings are old.

The windings of transformer windings in two variants are shown in figure 3. Detailed information about the windings of transformers is looked at in the article "Group of transformer windings".

Figure 3

Z'ednannya in trikutnik elektropryymachiv and capacitor batteries.

The windings of electric motors in the windings are shown in Figures 4, but – in. With whom the little one 4, but windings and z'єdnаnі and roztashovanі trikutnikom; for baby 4, b windings, ale roztashovani dovilno; for baby 4, in windings are ruffled with zirkoy, ale z'ednani at trikutnik. On baby 4, G windings roztashovanі trikutnik, ale.

Figure 4

All these little ones are supported, but on the right, it’s not so much about the fact that the image of the electric devices on the chairs is stashed (though they are often hand-stashed vidpovidno to the appearance of the day), but in the fact that it’s eaten: or the end of one winding with an ear of another. For the first one, the z'ednannya comes out at the star, for the other - at the trikutnik.

Z'ednannya in trikutnik capacitor banks is shown in fig. d.

On baby 4, e shown z'ednannya at trikutnik lamps. Wanting lamps territorially scattered in different apartments, but the stinks are combined at the group in the borders of the skin apartment, then at the group of risers 2 i, nareshti, qi groups are joined in trikutnik on the entrance shield 1 . Note: before the entrance shield, the supply is three-phase, after the entrance shield (at risers and apartments) it is single-phase, although it is switched on between two phases.

On what basis is the idea that living in two phases is called single-phase? On this support, which change the struma in both wires, to which the voltage is added, it is necessary, however, that at the same time the struma pass through those same phases.

Video 1

1 The presence of a struma in a closed circuit also means that there is no struma in the phase windings. Strumi at the phase windings inspire their interests.

U l = U f

I A, I B, I C - linear strumi;

I ab, I bc, I ca - phase struma.

Linear and phasic streams of vanity are related to each other by Kirchhoff's first law for knots a, b, c.

Linear strum is more expensive geometrical difference in phase strums.

The left and right parts of the equal system, (3.20), are taken

İa + ib + ic = 0,

tobto. the sum of complexes of linear streams is equal to zero, both for symmetric, and for non-symmetric vanishing.

With symmetrical vanishing

Z ab= Z bc = Z ca= Z e jφ ,

tobto. Z ab = Z bc = Z ca = Z, φ ab = φ bc = φ ca = φ.

Since the linear (stink and phase) voltages U AB, U BC, U CA are symmetrical, then the phase streams establish a symmetrical system

İab = Úab/Zab; İbc = Úbc/Zbc; İca = Úca/Zca.

The absolute values of them increase, and the destruction in phase is equal to 120°.

Linear streams

İa = İab - İca; ib = İbc – İab; ic = İca – İbc;

they also establish a symmetrical system of streams (Fig. 3.13, 3.14).

In this way, when the value of the linear struma is set by the tricot, the value of the linear struma, scho diє, with a symmetrical thrust, is times greater than the value of the phase struma i U L \u003d U F; I L \u003d I F.

In case of equal phase advancement, the development of a three-phase lancet lancet with a tricot can be brought up to a development of one phase.

Phase voltage U Ф \u003d U L. Phase stream I Ф \u003d U Ф / Z Ф, linear stream I L \u003d I Ф, cut zsuvu in phase φ \u003d arctg (X Ф / R Ф).

From the vector diagrams it can be seen that

I l = √3 I f with symmetrical vanishing.

The vector diagram for the dropdown, if the ab phase is actively induced, the bc phase is active-inductive, and the ca phase is actively-induced is shown in fig. 3.16 topographic diagram - in fig. 3.17.

Pobudov’s vectors

When connecting phase windings three-phase generator with a tricot (Fig. 1) the cob H "of one phase goes back to the end K" іnshey, the cob іnshої N" - to the end of the third K"" and the ear of the third N "" phase goes back to the end of the first N".

The phases of the generator windings establish a closed circuit with a small internal support. Ale for symmetrical e.d.s. (Equal in magnitude and however broken one or the other) in phases i with the inclusion of an outer lance, the strum in the circuit is equal to zero, since the sum of three symmetrical e.d.s. at any moment it is worth zero. With such a load, the voltages between the line wires are equal to the voltages on the phase windings:

Since the three phases of the voltage generator are absolutely the same, then the line wires flow evenly. Skin from these linear strums is more geometrical strums in two summative phases. Thus, the vector of the linear struma I is the most important geometric sum of the vectors in the phases I ca and I cb (Fig. 2, a). The vectors of the phase streams move one at a time to one at a 120° angle (Fig. 2, b).

Rice. 1. Z'ednannya windings of the generator trikutnikom.

Z baby 2 b is clear, what is the absolute value of the linear struma

Similar to generator windings triphasic desire maybe a tricoutnik.

Rice. 2. vector diagram strumiv.

So, three-phase electric motors are protected on the windings in a fallow way in a line in a circle Y or a tricotnik Δ.

Like in the measure there is no zero dart and, in such a rank, I can be at my order three line voltages, Vіn you can piece-by-piece create a phase voltage. For tsієї mark three same supports (navantazhennya) include at the measure behind the zirka scheme. The skin from the nipple will turn on to the phase voltage (Fig. 3):

Z'ednannya windings of the generator behind the scheme trikutnik zastosovuyut head rank at overflowing power plants of low intensity with a fenced length of the fence (power plants of electric shearing units and іn).

At chotiriprovidnіy three-phase system zero wire overhead grounding at power plants, at railroad fences and through the lines along the line. This is carried out for grounding of metal cases in the strum receivers at the rescuer.

Rice. 3. Inclusion of three strum receivers equal in support behind the star pattern into three linear darts.

Rice. 4. Scheme of inclusion in a three-phase chotiriprovidna line of lighting (220 V) and power (380 V) supply.

On little 4, a diagram is drawn for inclusion in a three-phase chotiriprovidna line of illumination and power supply. Illumination voltage is switched on for a phase voltage of 220 V. Switch on equally to single-phase voltage supply with three phases. With the help of a method along one street locality for lighting, conduct one phase with a zero wire, along the second - another phase and zero wire, on the third - third and zero wire, etc.