JPH063776B2 - Adjustable reactor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a variable reactor in which reactances are adjusted in multiple stages by using a plurality of closed magnetic circuit cores.

[Prior Art] Conventionally, as a variable reactor capable of adjusting a reactance according to a load, one which controls opening / closing of a short-circuit switch connected to a secondary circuit has been proposed.
In Japanese Patent Laid-Open No. 59-25204, a plurality of control windings are provided inside the main winding with their axes parallel to each other.
Alternatively, by providing an iron core that passes through the control winding and a magnetic path core that surrounds the outside of the main winding and bridges both ends of the iron core in common or separately, select a short-circuit switch connected to the control winding. What is opened and closed is shown.

[Problems to be solved by the present invention] However, in the case where the main winding is surrounded by the iron core and the control winding is provided inside the main winding, the reactor capacity is increased by sequentially short-circuiting the control winding. Then, the primary current increases and the secondary current also increases and heat is generated. However, since the outer circumference is surrounded by the main winding, the cooling effect of the main winding as well as the control winding decreases, There is a drawback that the iron core must be enlarged.

[Means for Solving the Problems] In view of the above points, the present invention provides a reactor that has a good cooling effect, can reliably obtain an energy saving effect, and can perform power factor adjustment and phase adjustment at low cost. A primary winding that commonly surrounds each leg of a plurality of closed magnetic circuit cores, and a secondary winding that is separately wound around at least two other core legs outside the primary winding. A wire and a short-circuit switch connected to each secondary winding circuit are provided, and a required reactance is obtained by a combination of opening and closing of the short-circuit switch.

Therefore, it is preferable to dispose the two-leg iron cores radially as the closed magnetic circuit iron core or to arrange the three-leg iron cores substantially in parallel.

[Operation] Therefore, when all the short-circuit switches of the secondary winding circuit are in the open state, the reactance value becomes the maximum value due to the decrease in the magnetic permeability path of the iron core, and the short-circuit switches are sequentially closed. Accordingly, the reactance value is correspondingly decreased, and the reactance value is minimized when all the short circuit switches are closed.

Therefore, various reactances can be obtained by combining the number of turns of each secondary winding and the open / close state of the short-circuit switch, and by increasing the number of secondary windings,
Finer adjustments can be made.

Further, since the primary winding commonly surrounds only one leg of each core, the winding can be made small, and the secondary winding is arranged outside the primary winding, and each of them is independently wound. Because it is turned,
The mutual distances can be sufficiently separated, the cooling effect is improved, and the current capacity can be increased.

In addition, by arranging two-leg iron cores radially as a closed magnetic circuit core or arranging three-leg iron cores substantially in parallel, winding of the primary winding is facilitated and the primary winding is attached to the central leg of the three-leg iron core. It is also possible to increase the number of adjustment steps by increasing the number of secondary windings by providing the wound secondary windings on both legs. In this case, it is preferable to enlarge the magnetic path of the central leg so as to eliminate the influence of saturation of the magnetic path.

If necessary, a magnetic gap or spacers having different magnetic resistances may be inserted in the iron core legs to adjust the magnetic resistance.

[Embodiment] An embodiment shown in the drawings will be described.

In FIG. 1 and FIG. 2, 1, 2, 3, and 4 are closed magnetic circuit cores composed of a plurality of (four in the embodiment) two-leg cores,
The iron cores are arranged radially on the base 5, and each iron core is composed of a laminated iron plate or a steel wire bundle, and a magnetic gap can be provided. 6 is a coil that surrounds the inner leg of each core in common
The next winding is connected to a load such as a power system via a lead wire 6a. Reference numerals 7, 8, 9, and 10 denote secondary windings separately wound around the outer legs of the iron cores, and short-circuit switches 11, 1
2, 13, 14 are connected. Note that another inductance can be inserted as a load on the secondary winding.

FIGS. 3 and 4 show an embodiment using a three-leg iron core. Reference numerals 21, 22, 23 are three-leg iron cores, and in this embodiment, three iron cores are used.
Individually provided, a magnetic gap 24 is provided by inserting an appropriate non-magnetic or spacer having a different magnetic resistance in each leg, but the present invention is not limited to this. 25 is a base, and 26 is a primary winding, which is wound so as to surround the central legs 21a, 22a and 23a of the three-leg iron core in common. 26a is a leader line, 27, 28, 2
Reference numerals 9, 30, and 31 denote secondary windings wound around outer legs of a three-leg iron core, respectively, which are separately wound outside the primary winding, and are short-circuited switches 32, 33, 34, 35, 36, respectively. Are connected.

In the three-leg iron core, since the magnetic flux from the primary winding 26 is shunted to both outer legs, the cross-sectional area of the magnetic path of the central leg is made larger than that of the outer legs on both sides.

The number of closed magnetic circuit cores and the number of secondary windings are not limited to those in the embodiment, and a necessary number is selected according to the capacity and the degree of adjustment.

Further, although shown as a single phase in the embodiment, a plurality of sets are arranged side by side according to the number of phases, or the iron cores are divided into groups according to the number of phases, and the primary winding is wound in each group. Can form a multi-phase reactor.

[Effects of the Present Invention] As described above, the present invention provides a plurality of closed magnetic circuit cores arranged radially or substantially parallel to each other, and provides a primary winding for winding one leg of each core in common. At least two of the outer legs
Secondary winding wound around the outside of the primary winding,
Since each secondary winding is provided with a short-circuit switch and the required reactance value is obtained by combining the switching of the secondary windings, the device is simple and inexpensive, and is easy to manufacture and adjust. , Reactance adjustment in a high range can be surely performed, and the primary winding only winds one leg of each iron core in common, and each secondary winding is also outside the primary winding. Since each iron core leg is wound, each winding can be miniaturized and sufficient strength against electrical and mechanical stress can be maintained, and each winding is placed separately with its own axis. As a result, the cooling effect is improved, the iron core and the winding having a small heat capacity can be used, and there is an effect that the entire size can be reduced.

By arranging the closed magnetic circuit cores as the two-leg cores in a radial manner, the primary winding can be formed into a cylindrical shape, and the manufacturing of the windings can be simplified.

When a three-leg iron core is used, the primary windings can be made smaller by arranging them in parallel, and the winding becomes easier.
This has the effect of increasing the number of secondary windings. By making the cross-sectional area of the magnetic path of the central leg larger than that of the outer leg, magnetic saturation can be prevented and the number of secondary windings can be increased.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan sectional view showing an embodiment of the present invention, FIG. 2 is a side view with a part in section, and FIG. 3 is a plan sectional view showing another embodiment. FIG. 4 is a side sectional view taken along the line AA. 1, 2, 3, 4 are two-leg iron cores, 5 is a base, 6 is a primary winding, 6a is a lead wire, 7, 8, 9, 10 are secondary windings, 1
1, 12, 13, 14 are short-circuit switches, 21, 22, 23
Is a three-leg iron core, 24 is a magnetic air gap, 25 is a base, 26 is a primary winding, 21a, 22a and 23a are central legs, 27 and 2
8, 29, 30, 31 are secondary windings, 32, 33, 34,
Reference numerals 35 and 36 are short-circuit switches.

Claims (4)

[Claims] 1. A primary winding having a plurality of closed magnetic circuit cores, each of which has one leg commonly surrounded, and a primary winding wound around the core, and at least two legs outside the primary winding. A variable-type reactor, comprising: a secondary winding wound around a coil and a short-circuit switch connected to each of the secondary windings, and the short-circuit switch is selectively opened and closed so as to obtain a required reactance. 2. A plurality of two-leg iron cores are arranged radially, and a primary winding that commonly surrounds an inner iron core leg and at least two outer iron core legs are respectively provided with secondary windings that are separately wound. The variable reactor according to claim 1. 3. A plurality of three-leg iron cores are arranged substantially parallel to each other, and a primary winding that commonly surrounds a central leg of each iron core and a secondary winding that is separately wound around at least two outer legs are provided. The deformable reactor according to claim 1. 4. The variable reactor according to claim 3, wherein the cross-sectional area of the magnetic path of the central leg is larger than the cross-sectional area of the magnetic path of the outer leg.