JPH0423294Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to improvements in electromagnetic induction equipment, particularly its magnetic shield. Magnetic shielding is usually used in electromagnetic induction equipment to prevent overheating of tanks and reduce stray loss.

FIGS. 1 and 2 show an example of the arrangement of a conventional magnetic shield in a single-phase transformer using a three-leg iron core. Note that FIG. 1 is a side sectional view, and FIG. 2 is a plan sectional view. In these figures 1
2 is a transformer tank, and 2 is a three-leg iron core, which is made up of legs around which windings are wound and a yoke part that forms a magnetic circuit with the outer periphery of the windings. 3 is a core stop plate, 4 is a core clamping fitting, 5 is a low voltage winding wound around the core,
Similarly, 6 is a high-voltage winding, and 7 is a magnetic shield made of a laminated iron core, and an appropriate number of these are attached to the inner wall of the tank 1.

In such a configuration, leakage magnetic flux generated by current flowing through both the high-voltage and low-voltage windings invades the core stop plate 3, the core clamping fitting 4, and the magnetic shield 7. The rate of penetration into each is determined by the magnetic resistance of each. Among these, the leakage magnetic flux that enters the magnetic shield 7 is attracted to the magnetic shield 7, so that it bends in the radial direction of the windings at both ends of the high-voltage and low-voltage windings 5 and 6, as shown by broken lines in FIG. It turns out.

For this reason, in addition to an increase in stray loss within the winding, a portion of the leakage magnetic flux also reaches the core clamping fitting 4, so that stray loss also occurs in this portion.

Furthermore, as shown in Fig. 2, the amount of magnetic flux penetrating the magnetic shield 7 is large in the part near the winding, and small in the part far from the winding, so the magnetic shield is not used effectively. There was also a drawback.

This invention was made in order to eliminate such drawbacks. An embodiment of this invention shown in the figure will be described below.

Fig. 3 is a front sectional view showing an embodiment of a transformer using a single-phase three-legged core, and Fig. 4 is a side sectional view.
FIG. 5 is also a plan sectional view. In these figures, 1 is the transformer tank, 2 is the single-phase three-legged core housed in this tank, 3 is the core stop plate, 4 is the core clamp, and 5 is the core wrapped around the center leg of the core. A low-voltage winding, 6 is a high-voltage winding, and 10 and 11 are first and second magnetic shields provided at the upper and lower ends of the winding, which are composed of a laminated core. They are arranged on both sides along the stacking direction of the upper and lower yoke parts of No. 3.
12 and 13 are the second ones attached to the inner wall of the tank.
and a fourth magnetic shield, which is composed of a laminated core, and as shown in FIG. 5, one end of the first magnetic shield 10 and the third magnetic shield 12 face each other with a small space interposed therebetween, , the other end of the first magnetic shield 10 and the fourth magnetic shield 13 face each other across a small space, while the third magnetic shield 13
As shown in the figure, one end of the second magnetic shield 11 and the third magnetic shield 12 and the other end of the second magnetic shield 11 and the fourth magnetic shield 13 face each other with a small space interposed therebetween, and substantially It is designed to form a closed magnetic path.

As a result of this configuration, leakage magnetic flux generated between the high-voltage winding 6 and the low-voltage winding 5 is caused by the gap between the windings → the first magnetic shield at the upper end of the winding, as shown by the broken line in FIG. 10 -> third or fourth magnetic shield 12 or 13 on the tank inner wall -> second magnetic shield 11 at the lower end of the winding -> passes through a closed magnetic path by a magnetic shield called the air gap between the windings.

In other words, since magnetic shields are provided at the upper and lower ends of the windings, most of the leakage magnetic flux generated between the high and low voltage windings is absorbed by these magnetic shields, reducing the bending of the windings in the radial direction. In addition to improving the magnetic flux distribution, the amount of magnetic flux penetrating the core stop plate 3, tank 1, and core clamping fittings 4 is reduced, which reduces stray loss in the windings and core stop plate.
It is possible to reduce stray loss that occurs in tanks and iron core fasteners.

Furthermore, since the magnetic shield 7 on the inner surface of the tank 1 facing the high voltage winding 6 is no longer necessary, it is sufficient to ensure the required insulation distance between the high voltage winding 6 and the inner surface of the tank 1, and the magnetic shield 7 The distance occupied by the tank is shortened, and the size of the tank 1 can also be reduced.

In addition, although the above explanation targeted transformers,
It goes without saying that the same effect can be obtained even if the present invention is applied to a single-phase reactor having a winding wound around an iron core.

[Brief explanation of drawings]

1 and 2 are schematic diagrams showing the arrangement of magnetic shields in a conventional single-phase transformer, with FIG. 1 being a side sectional view and FIG. 2 being a plan sectional view. Figure 3~
Figure 5 shows one embodiment of this invention.
The figure is a front sectional view, FIG. 4 is a side sectional view, and FIG. 5 is a plan sectional view. In the figure, 1 is a tank, 2 is an iron core, 5 is a low voltage winding,
6 is a high voltage winding, 10 is a first magnetic shield, 11
is a second magnetic shield, 12 is a third magnetic shield, and 13 is a fourth magnetic shield. Note that the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] An electromagnetic induction device having an iron core housed in a tank, a winding wound around the iron core, and iron core clamping fittings arranged at both upper and lower ends of the winding to sandwich the iron core in the stacking direction. The device is an electromagnetic induction device including magnetic shields disposed at both upper and lower ends of the winding and inside the tank, wherein the magnetic shields cooperate to form a substantially rectangular closed magnetic path. , both the upper and lower ends of the winding,
It consists of first and second magnetic shields provided between the iron core clamping fitting and third and fourth magnetic shields provided on the inner wall of the tank corresponding to the laminated layer direction of the iron core. , the first and second magnetic shields extend from the winding toward the tank such that their abutting portions with the third and fourth magnetic shields face each other with a small space between them. Features of electromagnetic induction equipment.