JPS5946406B2 - stationary induction equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to static induction equipment, such as a transformer or a reactor.

In recent years, the capacity of stationary induction devices such as transformers has tended to increase, and leakage magnetic flux from windings and lead wires has also increased accordingly.

Along with this increase in leakage magnetic flux, prevention of local temperature rise in the transformer structure and reduction of generated loss are viewed as problems from the viewpoint of performance, durability, etc. An example of this is iron core clamping fittings for stationary induction equipment such as transformers.

This will be explained using FIGS. 1 and 2 using a transformer as an example. In the figure, reference numeral 1 indicates a core leg 3 having upper and lower core yokes 2a and 2b, 4 indicates inner and outer windings wound around the core leg 1, 5a and 5b indicate upper core clamping fittings, 6a, 6
b is a lower iron core tightening fitting, an upper iron core tightening fitting 5a,
The upper yoke 2a is held in the horizontal direction by the upper yoke 5b, and the lower yoke 2b is held in the horizontal direction by the lower iron core clamping fittings 6a and 6b.

1a and 7b are upper and lower core tightening fittings 5a and 5b, and 6
A plurality of connecting fittings are provided to connect a and 6b so that the iron core will not be distorted even if the load when lifting the contents of the transformer or the mechanical force during a short circuit is applied to the iron core.

Incidentally, B is a transformer oil tank that houses each of the above-mentioned parts.
However, in a conventional transformer with such a configuration, the leakage magnetic flux from the three windings 4 is partially diverted to near the upper surface of the yoke 2a of the iron core, as shown by the solid line arrow in Fig. 1. It invades the vicinity of the top surface of the core fastening fittings 5a and 5b and the vicinity of the connecting fitting 7a that connects the two.

Furthermore, lead wires (not shown) are connected near the fastening fittings 5a and 5b.
In the structure in which the lead wires are provided, the leakage magnetic flux from the lead wires overlaps with the leakage magnetic flux from the windings 3 and 4 described above.
Therefore, the iron core clamping fittings 5a,
5b and the connecting fitting 7a that connects them, a circulating eddy current is induced as shown by the dotted arrow in FIG.
and cause a decrease in efficiency. The present invention has been made in view of the above points, and its purpose is to minimize heat loss, improve reliability, and minimize the decrease in efficiency even when eddy currents are induced by leakage magnetic flux. Our aim is to provide stationary guidance equipment that can

The present invention provides two magnetic shields made of highly conductive material on the top and bottom surfaces of two core rolling fittings that are horizontally sandwiched by connecting each of the upper and lower yokes of the core leg with a plurality of connecting fittings. The initial objective was achieved by providing plates in the longitudinal direction and connecting at least both ends with a highly conductive member.

The present invention will be described below based on embodiments shown in the drawings.

Incidentally, the same reference numerals are used for the same parts as in the past. Third
3 and 4 show an embodiment of the present invention, but the schematic structure is almost the same as that of the conventional one, so the explanation here will be omitted. In one embodiment of the present invention, magnetic shield plates 10a, 10b made of a highly conductive material are provided on the top surfaces of core clamping fittings 5a, 5b that sandwich the upper yoke 2a, and both shield plates 10a, 10b are provided. are electrically conductively coupled by a highly conductive member 20 at both ends and between the winding phases.

Therefore, if the configuration of this embodiment is adopted, the leakage magnetic flux from the windings 3 and 4 and the lead wire (not shown) will be transmitted to the upper yoke 2a.
Most of the eddy current that enters the vicinity of the upper surface in large quantities and flows back through the core clamping fittings 5a, 5b and the connecting fitting 7a is caused by the fourth
Since it circulates between the magnetic shields 10a, 10b and the highly conductive member 20 as shown by the chain lines in the figure, heat loss can be reduced.

That is, the iron core tightening fittings 5a, 5b and the connecting fitting 7a
The member is made of, for example, iron. The magnetic shields 10a, 10b and the highly conductive member 20 are made of a member having an electrical resistance smaller than that of a core fastening fitting made of copper, aluminum, etc., for example. In the present invention, since the magnetic shields 10a, 10b and the highly conductive member 20 are rearranged along the core fastening fittings 5a, 5b and the connecting fitting 7a, most of the eddy current is transferred to the magnetic shield 10a.
, 10b and the highly conductive member 20, and compared to the conventional case where it flows to the core clamping fittings 5a, 5b and the connecting fitting 7a, heat loss can be reduced and thermal cooling is also good, so the overall can reduce total heat loss. Furthermore, lead wires (not shown) are arranged near the core fasteners 5a, 5b, and even if a large amount of leakage magnetic flux intrudes from this, the shielding effect of the shield plates 10a, 10b prevents the core fasteners 5a, 5b from reaching the core fasteners 5a, 5b. Heat loss due to generated eddy currents is reduced, and a similar effect can be obtained. In the above-mentioned embodiment, the core fastening fittings 5a and 5b of the upper yoke 2a were described, but the same can be applied to the core tightening fittings 6a and 6b of the lower yoke 2b, and similar effects can be obtained. Needless to say, it can be done.

In addition, although the above-mentioned embodiment was explained using a transformer as an example,
It can also be applied to other reactors as well. According to the stationary induction device of the present invention described above, each of the upper and lower yokes of the core leg is connected with a plurality of connecting metal fittings, so that the two iron core clamping metal fittings that are horizontally sandwiched have high conductivity. Since it is equipped with two magnetic shielding plates made of a material, even if a large amount of leakage magnetic flux intrudes into the yoke and induces eddy currents that flow back through the core clamping metal fittings, most of the leakage flux that tries to flow is suppressed. The current flows through the magnetic shield plate with low electrical resistance, and therefore eddy current is less likely to flow through the iron core clamping fittings, reducing heat loss and suppressing local heat generation, improving the reliability and efficiency of stationary induction equipment. There is an effect that can be done.

[Brief explanation of the drawing]

Figure 1 is a front view showing the schematic structure of a conventional transformer with only the oil tank in section; Figure 2 is a plan view showing only the oil tank in section;
The figure shows an embodiment of the stationary induction device of the present invention, and is an enlarged view of the upper yoke of the transformer, and FIG. 4 is a plan view thereof. 1... Iron core leg, 2a, 2b... Yoke,
3...Inner winding, 4...Outer winding, 5
a, 5b... Upper core tightening fittings, 6a, 6b
...Lower iron core tightening fittings, 7a, 7b...
...Connection fittings, 8...Transformer oil tank.

Claims (1)

[Claims] 1.Equipped with an iron core leg having upper and lower yokes and a winding wound around the iron core leg, core fastening fittings parallel to the longitudinal direction are arranged on the sides of the upper and lower yokes, respectively, and the upper and lower yokes are In a device in which the contents of the device are horizontally sandwiched by connecting two core tightening fittings with a plurality of connecting fittings arranged on the topmost surface or the bottommost surface, the contents of the device are stored in an oil tank. Two magnetic shield plates made of a highly conductive material extending in the longitudinal direction are provided between the fastening metal fitting and the connecting metal fitting, and
A stationary induction device characterized in that at least both ends of two magnetic shield plates are connected with a highly conductive member.