JP7377167B2 - stationary induction equipment - Google Patents

Description

The present invention relates to stationary induction equipment, and particularly to a structure in which a coil is wound around an iron core using an aluminum composition material.

Background art in this technical field includes Patent Document 1. Patent Document 1 describes electrically welding a lead wire of a winding made of an aluminum composition material and a copper wiring connected to a terminal in an electrical connection device between a winding coil made of an aluminum composition material and a copper wire. ing.

JP2014-44887A

In Patent Document 1, a lead wire made of an aluminum composition material is used to connect to a copper wiring, resulting in a complicated connection structure.

An object of the present invention is to provide a stationary induction device having a structure in which a coil is wound with an aluminum composition material around an iron core, and which has a simple wiring connection structure.

To give one example, the present invention provides a stationary induction device equipped with a coil wound with a coil wire connected to a tap wire, in which the coil wire is made of an aluminum composition material and the tap wire is made of a copper composition material. The copper composition material of the tap wire is directly bonded to the aluminum composition material of the coil wire, and the bonding surface between the coil wire and the tap wire is a side surface of the coil wire that faces in the direction in which the tap wire extends. Upset welding is performed with the tip of the tap wire aligned in a T-shape against the part to be fixed , and the distance between the clamp position where the electrode is clamped on the tap wire fixed by the movable part of the upset welding machine and the joint surface is By energizing and pressurizing the electrode of the coil wire fixed by the fixing part of the upset welding machine at a distance greater than the distance between the clamp position and the joint surface, the tap wire is stronger than the coil wire. , the structure is blackened far from the bonding surface .

According to the present invention, it is possible to provide a stationary induction device having a structure in which a coil is wound with an aluminum composition material around an iron core, and a stationary induction device having a simple wiring connection structure.

FIG. 2 is an external view of an oil-immersed transformer containing a coil core assembly in an example. FIG. 2 is a perspective view showing the appearance of a coil for an oil-immersed transformer in FIG. 1. FIG. FIG. 3 is an enlarged view of a joint between a coil wire and a tap wire in an example. This is a first modification of FIG. 3. This is a second modification example of FIG. 3.

Among stationary induction devices such as transformers and reactors, this embodiment will be explained using a transformer.

FIG. 1 is an external view of an oil-immersed transformer containing a coil core assembly according to this embodiment. In FIG. 1, 900 is a tank of the main body of an oil-immersed transformer, 910 is a cooling rib provided around the tank, and 920 is a welding line welded and fixed above and below the cooling rib 910. The weld line 920 provides strength to the cooling rib 910 and prevents it from deforming. 930 is a high voltage side terminal (primary side terminal), which is a terminal for connecting a high voltage power source transmitted from a power plant, and is connected to a tap wire connected to a high voltage coil. Reference numeral 940 is a low voltage terminal (secondary side terminal), which is connected to send a voltage generally stepped down by a transformer to the load side, and is connected to a tap wire connected to the low voltage coil.

FIG. 2 is a perspective view showing the appearance of the coil for the oil-immersed transformer in FIG. 1. FIG. In FIG. 2, the coil 10 in this embodiment is composed of three parts: a winding frame 11, a low voltage coil 12, and a high voltage coil 13. The high voltage coil 13 has a coil wire 14 wound spirally in the axial direction and stacked in multiple stages in the coil radial direction. Reference numeral 15 denotes a tap wire, and the tap wire 15 is connected to the coil wire 14 with a specified number of turns of the high voltage coil 13, and the subsequent coil wires 14 are wound on the tap wire 15.

FIG. 3 is an enlarged view of the joint between the coil wire 14 and the tap wire 15 in this embodiment. In FIG. 3, the coil wire 14 of this embodiment is made of an aluminum wire with a cross-sectional size of 7 mm x 7 mm, and the tap wire 15 is made of a copper wire with a cross-sectional size of 7 mm x 7 mm. The wire 15 is joined to the coil wire 14 in a T-shape butted state. This joining is done with an upset welder.

The procedure for welding with an upset welding machine is as follows.

First, the coil wire 14 is fixed to the fixed part of the upset welding machine, and the electrode of the upset welding machine is clamped.

Next, the tap wire 15 is fixed to the movable part of the upset welding machine, and the electrode of the upset welding machine is clamped. The distance from the abutting surface of the tap wire 15 to the clamp position is made longer than the distance from the abutting surface of the coil wire 14 to the clamp position .

Next, the movable part of the upset welding machine is brought close to the fixed part, and the tip of the tap wire 15 is butted against the side of the coil wire 14 in a T shape.

Next, the temperature at the joint between the coil wire 14 and the tap wire 15 is increased by starting to supply electricity to the clamp from the upset welding machine.

Next, move the movable part of the upset welding machine closer to the fixed part. As a result, the joint surface between the side surface of the coil wire 14 and the tip end surface of the tap wire 15 is pressurized.

The energization conditions such as voltage, current, and energization time are controlled so that the temperature of the joint surface is heated to less than the melting temperature of the tap wire 15 material made of copper-based material and higher than the melting temperature of the coil wire 14 made of aluminum-based material. .

Then, the current is cut off at the timing when the temperature of the bonding surface has risen to a temperature appropriate for bonding.

Next, cool. In this embodiment, the pressurization is maintained even during cooling, and the pressurization is stopped depending on whether the amount of the tap wire 15 protruding (embedded) into the coil wire 14 exceeds a certain level, or depending on the amount of movement of the movable part of the upset welding machine. stop.

At this time, the pressurizing conditions and energizing conditions differ depending on the product specifications, but as a result of evaluation from the viewpoint of the joint strength and energizing characteristics of the joints when applying voltage and current in transformer applications, the following conditions were found. It is necessary to satisfy at least one condition, preferably two or more conditions.

(1) Make the distance between the support position of the tap wire 15 fixed by the movable part of the upset welding machine and the joint surface greater than the distance between the support position of the coil wire 14 fixed by the fixed part of the upset welder and the joint surface. . Then, energize and pressurize. As a result, a position further away from the bonding surface of the tap wire 15 than the coil wire 14 was blackened. Further, the residual strain on the side surface opposite to the side surface of the coil wire 14 against which the tip end surface of the tap wire 15 abuts becomes tensile strain (stress) or no strain. This is because, although the heat generation point due to energization is the joint surface, the coil wire 14 is not only in the tip direction of the tap wire 15 (in the width direction of the coil wire), but also in the length direction of the coil wire 14 and at the fixed part of the upset welding machine. Also diffuses, resulting in extremely high cooling properties. As a result, compressive strain occurs only near the joint surfaces.
(2) The aluminum-based material of the coil wire 14 is applied not only to the tip of the tap wire 15 but also to all the joint surfaces between the coil wire 14 and the tap wire 15 that are visible from the outside (the part where the joint surface is exposed to the surface). Upset occurs.
(3) There is a relationship of P≦(1/2)×W between the width W of the tap wire 15 (wire width) and the amount P of the tap wire 15 protruding from the side of the coil wire 14 into the inside. satisfy.

By satisfying the above conditions, the current conduction characteristics and bonding strength of the joint between the coil wire and the tap wire are ensured, and a transformer with low power consumption and a simple wiring connection structure can be provided.

FIG. 4 is a first modification of FIG. 3. In FIG. 3, the tip end face is cut perpendicularly to the extending direction of the tap wire, whereas in FIG. 4, it is cut diagonally. Even with such a bonding shape shown in FIG. 4, the current conduction characteristics and bonding strength of the bonded portion for use in a transformer can be ensured under the conditions (1) to (3) above.

FIG. 5 is a second modification of FIG. 3. In FIG. 3, the end face is a cut surface perpendicular to the extending direction of the tap wire, whereas in FIG. 5, the shape of the joint surface seen from the top is a curved surface. Even with such a bonding shape shown in FIG. 5, the current conduction characteristics and bonding strength of the bonded portion for use in a transformer can be ensured under the conditions (1) to (3) above.

As described above, in this example, in a stationary induction device equipped with a coil connected to a tap wire, the tip of the tap wire made of copper composition material is upset welded to the side surface of the coil wire made of aluminum composition material. , it is possible to simplify the manufacturing process of static induction equipment with a simple wiring connection structure, ensure the current conduction characteristics and bond strength of the joint between the coil wire and the tap wire, and provide a static induction equipment with low power consumption. .

Although the embodiments have been described above, the present invention is not limited to the embodiments described above, and includes various modifications. For example, the embodiments described above are described in detail to explain the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to having all the configurations described.

10: Coil, 11: Winding frame, 12: Low voltage coil, 13: High voltage coil, 14: Coil wire, 15: Tap wire, 900: Tank of oil-immersed transformer body, 910: Cooling rib, 920: Welding Wire, 930: High voltage side terminal (primary side terminal), 940: Low voltage terminal (secondary side terminal)

Claims (7)

In stationary induction equipment with a coil wound with a coil wire connected to a tap wire,
The coil wire is made of aluminum composition material,
The tap wire is made of a copper composition material,
The copper composition material of the tap wire is directly joined to the aluminum composition material of the coil wire,
The joint surface between the coil wire and the tap wire is made by upset welding with the tip of the tap wire butted against a portion of the side surface of the coil wire that faces the extending direction of the tap wire in a T-shape. and
The distance between the joint surface and the clamp position where the electrode is clamped on the tap wire fixed by the movable part of the upset welding machine is the distance between the clamp position where the electrode is clamped on the coil wire fixed by the fixed part of the upset welder and the distance between the clamp position where the electrode is clamped on the coil wire fixed by the fixed part of the upset welder and The static induction is characterized in that the tapped wire is blackened farther from the bonding surface than the coil wire by applying current and applying pressure at a distance from the bonding surface. device. The stationary induction device according to claim 1,
A static induction device characterized in that residual strain on a side surface opposite to the side surface of the coil wire against which the tip of the tap wire abuts is no strain or tensile strain. The stationary induction device according to claim 1,
A stationary induction device characterized in that the aluminum composition material of the coil wire is present on the bonding surface exposed on the surface of the coil wire and the tap wire. The stationary induction device according to claim 1,
a tip of the tap wire protrudes into the coil wire;
A stationary induction characterized in that P≦(1/2)×W holds between the width W of the tap wire and the amount P of protrusion of the tip of the tap wire into the coil wire. device. The stationary guidance device according to any one of claims 1 to 4 ,
A stationary induction device characterized in that a joint surface between the coil wire and the tap wire is a cut surface perpendicular to the extending direction of the tap wire. The stationary guidance device according to any one of claims 1 to 4 ,
A stationary induction device characterized in that a joint surface between the coil wire and the tap wire is a cut surface oblique to the extending direction of the tap wire. The stationary guidance device according to any one of claims 1 to 4 ,
A stationary induction device characterized in that a joint surface between the coil wire and the tap wire has a curved shape .

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