JPS6336509A - Transformer with on-load voltage regulator - Google Patents

Abstract

PURPOSE:To prevent the changing point of a tap changer from fusing by disposing the regulator-side secondary windings of two parallel circuits of the secondary windings at axial both ends of the exciting winding, thereby enabling the circulating current flowing through the secondary windings to be suppressed. CONSTITUTION:A main transformer TR consists of a primary winding 3 placed outside a core 1, and secondary windings 4a, 4b composed of two parallel circuits. A regulator LVR consists of an exciting winding 5 placed outside a core 2 connected in parallel with the primary winding 3, regulator-side secondary windings 6a, 6b respectively connected in series with the secondary windings 4a, 4b, and a tap winding 7 placed outside them. Since the regulator- side secondary windings 6a, 6b are placed at axial both ends of the exciting winding 5, the distance between the two parallel circuits of the secondary windings 6a, 6b can be made large and the leakage inductance also becomes large, thereby enabling the suppression of the circulating current due to the mechanical time difference between two diverter switches TAP which are used in parallel.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a transformer with an on-load voltage regulator, and particularly to a transformer with an on-load voltage regulator that has an on-load voltage regulator suitable for switching large currents. .

[Conventional technology]

In the conventional device, as shown in FIG. 7 and described in Japanese Patent Application Laid-Open No. 57-120320, the leakage impedance is sufficiently reduced by winding the secondary windings 4a and 4b of the main transformer in half in opposite directions. Since it cannot be made larger, the secondary windings 4a and 4b are further moved to the load voltage regulator side and the current dividing windings 6a' and 6 are
ty', the ratio of the regulator side secondary winding to the total windings is increased, and the number of turns is increased, thereby increasing the impedance. Furthermore, since the iron core of the regulator is generally smaller than that of the main transformer, the number of turns is greater than that of the main transformer.

[Problem that the invention seeks to solve]

Since the conventional transformer with on-load voltage regulator is configured as described above, it is effective in terms of leakage impedance, but winding resistance increases. For example, when the left and right taps are shifted by one step when switching taps, the mechanical time difference K between two switching switches used in parallel causes the circulating current flowing to the secondary winding side and the above-mentioned winding resistance. According to
There were disadvantages in that resistive losses occurred and the switching contacts of the switching switch could be damaged by melting. This drawback has not been taken into account in the conventional configuration.

The present invention aims to eliminate this drawback, and its object is to provide a transformer with an on-load voltage regulator that suppresses the circulating current flowing to the secondary winding side.

[Means for solving problems]

In order to achieve the above object, the present invention is characterized in that the regulator-side secondary windings of the two parallel circuits of the secondary windings are arranged at both ends of the excitation winding in the axial direction.

[For production]

Since the transformer with on-load voltage regulator according to the present invention is configured as described above, the distance between the upper and lower windings can be increased, and the leakage impedance, which is mostly mutual inductance, can be increased. . In general, the leakage impedance IX between two windings arranged in a concentric cylindrical shape in a core type transformer is expressed as: IX = k-N, where k is the constant, N is the number of turns, and δ is the distance between the two windings. As expressed by the formula ``.delta.'', the distance increases in proportion to the distance between the two windings, but the phenomenon of the present invention described above can be equated with this example.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of a large-capacity transformer with an on-load voltage regulator. The main transformer TR is composed of a primary winding 3 disposed outside the iron core 1, and secondary windings 4a and 4b consisting of two parallel circuits. The regulator LVR includes an excitation winding 5 connected in parallel to the negative winding 3 and arranged outside the iron core 2, and a secondary winding 4a.
, 4b are connected in series to the regulator side secondary windings 6, respectively.
a, 6b, and a tap winding 7 placed outside of them.

The winding method of the regulator-side secondary windings 6a and 6b is as shown in FIG. The structure is such that the windings are wound in the same direction from 1 turn to1 to 16 turn t16.

With the above structure, the distance between the two parallel circuits of the regulator side secondary windings @6a and 6b can be increased, which increases the leakage impedance. As shown in FIG. 2, it is possible to suppress the circulating current due to the mechanical time lag of the switching switch TAP used in the two-piece differential train.

Also, when comparing this structure with the conventional structure shown in Fig. 7,
It would be possible to reduce the proportion of the regulator side secondary windings 6a and 6b in the entire secondary winding. Generally, in the main transformer TR and the regulator LVR, the iron core 1 of the main transformer TR is strong, so in order to ensure the same ground pressure, the winding resistance is smaller if the winding on the main transformer side has a larger proportion. Therefore, it is possible to reduce the winding resistance of the secondary winding, thereby reducing resistance loss.

Since the secondary winding 6a on the side of the load regulator has a folded structure as shown in FIG. The beginning of the winding is conductor A1 to conductor A8, conductor B1 to conductor B8, and the end of the winding is conductor A2 to conductor A9, and conductor B2 to conductor B9, and from K, the same symbol at the beginning and end of winding is connected. A wiring diagram of the entire secondary winding shown in can be formed. With this structure, the tap winding 7, which conventionally consisted of two pieces, can be reduced to one piece, and the circuits of independent individual switching switches TA'P for the A series and B series can be configured, which is economical. It is possible to provide a typical tap winding.

Each conductor S constituting the regulator side secondary windings 6a, 6b is connected to the fifth
As shown in the figure, by configuring the winding so that the shorter side is in the height direction, the height dimension of the winding can be shortened, and therefore each secondary winding can be moved closer to both ends of the winding. It is possible to increase the impedance.

In addition, as shown in FIG. 6, the regulator side secondary windings 6a, 6b
If divided into four parts and connected in series, each secondary winding 6a
, 6b can be further shortened in the height direction, and as a result, the impedance can be increased. Note that there are several methods of tap winding other than the above-mentioned example, and the same effects can be expected with any of the methods. Further, in this embodiment, an example of a single-phase three-winding transformer is shown, but the present invention can also be applied to a three-phase three-winding transformer or a three-phase single winding transformer.

〔Effect of the invention〕

As explained above, the present invention has devised the regulator-side secondary winding, so that the distance between the two regulator-side secondary windings can be increased. It is possible to suppress the circulating current flowing to the next winding, prevent melting of the switching point of the tap changer, and furthermore, it is possible to reduce the winding resistance and minimize resistance loss. Therefore, it is possible to provide an economical transformer with an on-load voltage regulator that reduces safety problems.

[Brief explanation of drawings]

Figure 1 is a structural diagram of a transformer with on-load voltage regulator according to an embodiment of the present invention, Figure 2 is a wiring diagram of the entire secondary winding according to an embodiment of the present invention, and Figure 3 is the regulator side. Configuration diagram of secondary winding,
Figure 4 is a configuration diagram of the tap winding, Figure 5 is a cross-sectional diagram of the conductor,
FIG. 6 is a configuration diagram showing another embodiment of the regulator side secondary winding,
FIG. 7 is a structural diagram of a conventional transformer with an on-load voltage regulator. 3...-Secondary winding, 4a, 4b...Secondary winding, 5...Excitation winding, 6a, 6b...
・Regulator side secondary winding, TR...Main transformer, LV
R...Inner iron type load voltage regulator. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. An excitation winding connected in parallel to the primary winding of the main transformer;
In a transformer with an on-load voltage regulator having an inner iron type on-load voltage regulator comprising a regulator-side secondary winding consisting of two parallel circuits each connected in series with the secondary winding of the main transformer. , A transformer with an on-load voltage regulator, characterized in that the regulator side secondary winding is arranged at both ends of the excitation winding in the axial direction. 2. In the item described in claim 1 above, the regulator-side secondary winding has a conductor constituting the regulator-side secondary winding such that the short side of the conductor is in the winding height direction. A transformer with an on-load voltage regulator, characterized in that it is configured by winding it so that 3. The voltage under load according to claim 1, wherein the regulator-side secondary winding is divided and arranged in parallel with the excitation winding. Transformer with regulator.