SU55255A1 - Device for smooth regulation of AC voltage - Google Patents

Description

The existing schemes of voltage regulation by magnetization are based on the principle of switching the phase conductors with iron into the dissection and changing the magnetic conductivity of the magnetic core of the electrodes by biasing with a direct current. As a result of a change in the self-induction, the throttle changes at the same amperage, the voltage drop across the choke. In some circuits, the choke is built into the transformer, making up part of its dissipation, which does not change the substance of the device.

The main disadvantages of this method are:

1. The voltage drop across the choke is perpendicular to the current vector. At the same time, the phase voltage vector approximately coincides with the current vector (for ordinary cos f). In the final stage, the adjustment is characterized by the vector diagram shown in FIG. 1. The source voltage E is the hypotenuse, and the receiver voltage E is the leg; AJ-throttle voltage drop.

Adjustment percentage

, -, i--

HER,

With a given weight of iron and. a magnetic circuit (including direct current windings) and at a given maximum operating current / check there is a well-defined range of possible variations of E:

- min - - mas.

The left limit is limited by the DC winding power, the right limit by the condition of the permissible content of higher harmonics (the ratio of DC and AC induction must not be lower than a certain value) and the minimum operating current that may occur during operation.

However, the difference change. goes much more slowly than change A, and the ratio

(El - 2) mln () „a

significantly closer to one than

In this way.

an attitude

E „„

Due to the perpendicularity of the vector Af to the current vector, it is necessary to take significantly larger throttle sizes to achieve this adjustment range.

2. The differential of A-Bui, due to the greatest force of direct current, which can be passed through the winding from the heating conditions, and the value of the maximum operating current, for the device must ensure the possibility of receiving at full flow. According to the author’s calculations, the economic optimum (to which a well-defined number of turns of the alternating current winding corresponds) lies near

- - .niax

Generally dbtsh can not be small. This voltage is a deadfall, which essentially causes the nominal voltage of the network to be increased by an amount and adds nothing to the range of adjustment.

3. The voltage drop is proportional to current only. At idle (/ 0) and low currents adjustment is generally impossible. With the reverse direction of the current / adjustment "to increase is not possible (adjustment g ±: ЕЕ is impossible).

Another disadvantage of the existing schemes is the loss of iron on the frame and on the connecting parts. To destroy even harmonics, the AC current must pass through two sections with opposite DC bias.

To achieve this, additional cores are used for DC winding that are not used or partially used as active material, i.e. not included in the weight of iron, which

determines power (DYah -)

/ apparatus (this weight includes only those parts that are fully excited by the alternating current field).

The present invention aims at eliminating the aforementioned disadvantages and consists in a special form of the device for controlling the AC voltage. As mentioned above, the proposed device uses the principle underlying a conventional booster transformer with a longitudinal magnetisation of direct current, but without moving parts.

In FIG. 1 shows a vector diagram of existing voltage regulating devices, FIG. 2-scheme of the proposed device.

Two magnetic cores a and b are equipped with two series-connected primary windings (excitation windings) Wa and Wi, alternating current, the voltage of which in total is equal to the phase

 - eb.

On the same magnetic cores au / donned are the secondary windings Wа and Wi ,, and, if on the magnetic core and the winding direction of the windings Wu and Wa are the same, then on the magnetic core b the winding direction of the winding Wb is opposite to the winding direction of the winding WüW ,, W. Wb - Wb

The secondary windings W „and Wb are connected in series with each other and inserted into the dissection of the phase conductor.

Differential voltage:

Ag - (e ,, - b).

Kpo.we, on both the magnetic cores a and and, the windings of the direct current Wpa and Wpb are mounted.

If the Wpa winding of the magnetic circuit a is wrapped around it with direct current and the Wpb winding does not flow around (or wrapped around it less), then w, e, and. If, on the contrary, the magnitude of the direct current in the winding Wpb is greater, then Av 0. The vector A has the direction of the phase pattern;

SO

Ae; fi; -

-EL Av ,,

where a is a real number.

With the passage of current /, not razugo zero, in fact, we have:

de x - | -; 3 /,

i.e., there is a constituent ur / perpendicular to the current vector. However, the term is decisive. Full adjustment range:

-Stk () Cniin

the so-called, “dead drop is absent.

However, if in the described scheme we confine ourselves to the two magnetic cores described above, there will be even harmonics.

To eliminate even harmonics in the device, two additional magnetic systems p and t, identical to the main ones, in which the primary windings Wn and

Wm and secondary windings Wrt and Wm

The parallel windings of the magnetic cores a and b are connected in parallel, and the magnetizing windings Wp ,, and Wpm are connected in series with the corresponding magnetic windings Wpa and Wpt: but wound in opposite directions with respect to the winding direction of these latter directions.

During the half cycle, the alternating and direct current vectors in one of the parallel magnetic cores are opposite and the magnetic permeability is high, so that the inductive resistance of the parallel windings is determined by another parallel magnetic circuit.

In the next half-period, the magnets seem to be swapped. As a result, the half-periods are symmetric and even harmonics are absent. Theoretical analysis shows that this circuit (parallel connection) is identical in its entirety to the circuit with consecutive magnetic path sections that are magnetized oppositely, but in the proposed device all the iron is used, including iron PM.

The author points out that if we compare the proposed device with cxei.:ou "adjustable throttle, then; iOH of the same power / ecoHbip; iomi of iron is primed in relation to:

| - / i2-L-tah0, 8 AEgpah g

 .0, 8 -

On this basis, the author concludes that in many cases the use of longitudinal bias schemes, due to the possibility of their implementation according to the invention, may be more expedient than the use of other devices for voltage regulation.

FIG. 2 shows a diagram of an apparatus for a single phase. In case of its application in a three-phase line, magnetic systems can be made as armored transformers.

The proposed device can also be built into the transformer by using additional cores in the latter.

PRED. inventions.

Claims (3)

1. Device for smooth voltage regulation of alternating current, made according to the type of booster transformer without moving elements and with longitudinal biasing by direct current, characterized in that both the primary and secondary windings with their halves connected in series and wound are primary halves according to and the secondary ones are differentially located on independent magnetic systems fitted with each magnetic windings. 2. The form of the device; According to claim 1, characterized in that, with the aim I of eliminating even harmonics, magnetic systems are used, and; The primary ones, in which the primary and secondary AC windings are respectively connected in parallel with the windings of the main systems, while the biasing windings are connected in series with the biasing windings of the main systems and are wound in the opposite direction to them. 3. In the device according to paragraphs. 1 and 2 use, in the case of a three-phase line, magnetic systems made as armor transformers.