JPH07320956A - Transformer with built-in lighting element - Google Patents

Abstract

PURPOSE:To provide an economical transformer with built-in lightning elements which can be manufactured in a compact state as a whole and has a light weight by supporting the lightning elements in such a state that the lightning elements are put between tap lead wires which connect a tap winding to an on-load tap switching device. CONSTITUTION:In a transformer in which a tap winding 2A wound around an iron core 1 is connected to an on-load tap switching device 3 through tap lead wires 4 drawn out from the winding 2A and lightning elements LA are connected to both ends of the winding 2A, the elements LA are fixed by putting the elements LA between the wires 4 and the potentials at the elements LA are made nearly equal to those at the wires 4 so as to minimize the dimensions among the winding, tanks, and metallic structures.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer having a lightning protection element (a non-linear resistance element such as a zinc oxide element) incorporated therein, and more particularly to a structure for supporting and fixing the lightning protection element.

[0002]

2. Description of the Related Art As a method of suppressing the potential rise of the tap winding and the shared voltage between the taps when a lightning impulse is applied to the transformer or a lightning surge enters, a lightning arrester element is provided at both ends of the tap winding. A method of inserting is known. FIG. 5 shows an example of the connection of the high voltage windings of the tap switching transformer during load to which such a lightning protection element is added, and FIG. 6 shows an example of the connection of the autotransformer.

In the case of a tap change transformer under load, FIG.
As shown in, the main winding 21 and the tap winding 22 are connected in series, and the tap switch device 3 at load is connected between the tap of the tap winding 22 and the neutral point N. A lightning protection element LA is connected in parallel to both ends of the tap winding 22. H is a high voltage line terminal.

In the case of a tap-changing autotransformer under load,
As shown in FIG. 6, a tap winding 33 is arranged between the series winding 31 and the shunt winding 32, and the tap polarity changeover switch Sw connected to both ends of the tap winding 33 is wound in series. One end of the wire 31 is connected, and the other end of the series winding 31 is connected to the high voltage line terminal H. One end of the common shunt winding 32 is connected to the low-voltage line terminal L, and is also connected to the tap of the tap winding 33 via the tap switching device 3 at the time of load, and the other end of the shunt winding 32 is a middle wire. It is connected to the sex point N. A lightning arrester LA is connected in parallel to both ends of the tap winding 33.

When the lightning protection element LA is built in the transformer, it is difficult to install it in the winding, and it is installed at the position shown in FIG. In FIG. 7, a tap switching device 3 under load is arranged next to a winding wire 2 wound around an iron core 1, and a tap lead wire 4 drawn from a tap winding wire 2A of each winding wire 2 is provided.
Thus, the tap winding 2A and the load tap switching device 3 are connected. The lightning arrester element LA is located at the side of the load tap switching device 3 (A in the figure), or at a position where the tap lead wire 4 extends from the tap winding 2A to the load tap switching device 3 (B of the figure). Is installed in. The tap lead wire 4 is supported and fixed by a cleat 5. The contents of the transformer including the iron core 1, the winding 2, the load tap switching device 3, and the like are housed inside the tank 6.

[0006]

However, with such a structure, when the tap winding is located at a high voltage portion such as an autotransformer, a high ground potential is applied to the lightning protection element, so that the winding, It is necessary to secure a sufficient insulation distance for the tap changer under load, the tank and other metal structures. For this reason, there have been problems such as an increase in the size of the contents of the transformer including the iron core and windings of the transformer, and an increase in the size of the tank.

The present invention has been made in view of the above points, and a lightning arrester is installed between the tap lead wires connecting the tap winding and the tap switching device under load, and the lightning arrester is provided by the tap lead wires. It is an object of the present invention to provide an economical and lightweight transformer with a built-in lightning protection element, which can be manufactured compactly by supporting the lightning protection element by sandwiching it and connecting the terminal of the lightning protection element to the tap lead wire.

[0008]

In order to achieve the above-mentioned object, the transformer with a built-in lightning protection device of the present invention has a lightning protection device installed between a tap winding and a tap lead wire connecting a tap switching device during load. The terminal of the lightning protection device is connected to the tap lead wire by being supported by the tap lead wire.
The tap lead wire is fixed by a cleat attached to an iron core fastening fitting or the like.

[0009]

In the structure of the transformer with a built-in lightning protection device of the present invention, the lightning protection device is installed between the tap windings and the tap lead wire that connects the tap switching device during load, and the tap lead wire supports the lightning protection device. , The lightning protection element has almost the same potential as the tap lead wire, and only the insulation dimension between the windings, tanks, etc. required by the tap lead wire is sufficient, and the increase in the insulation dimension between the winding, tank and metal structure is minimized. You can keep it to the limit. Further, since the lightning arrester element is sandwiched by the tap lead wires, the electric field concentration at the upper and lower ends of the lightning arrester element can be relaxed, and the electric field mitigating shields attached to both ends of the lightning arrester element can be made compact. . This eliminates the need to increase the dimensions between the shield and the windings and the tank.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a plan view showing an embodiment of a structure for installing a lightning protection element of a lightning protection element built-in transformer of the present invention. In FIG. 1, a tap switching device under load beside a winding wire 2 wound around an iron core 1. 3 is provided, and the tap lead wire 4 drawn from the tap winding 2A of each winding 2 connects the tap winding 2A and the tap switching device 3 under load. Lightning arrester LA
Is installed between the tap lead wires 4 on the way from the tap winding 2A to the load tap switching device 3. The tap lead wire 4 is supported and fixed by a cleat 5. The contents of the transformer including the iron core 1, the winding 2, the load tap switching device 3, and the like are housed inside the tank 6.

Next, the mounting structure of the lightning protection element will be described. 2, 3 and 4 are a side view, a plan view and a plan sectional view showing details of a portion where a lightning arrester is sandwiched between tap lead wires of a lightning arrester built-in transformer of the present invention. As shown in, the lightning arrester LA is fixed by being sandwiched between the plurality of tap lead wires 4 which are alternately distributed to the left and right sides. Shields 7A and 7B are attached to the upper limit terminals of the lightning protection element LA, and the tap winding 2
It is connected to the tap lead wires 4 connected to both ends of A. Further, the shields 7A and 7B have a shape matching the shape of the tap lead wire 4 (a substantially elliptical cap shape).
It has become.

[0012]

As described above, in the transformer with a built-in lightning arrester of the present invention, the lightning arrester is installed in the tap lead wire connecting the tap winding and the tap switching device under load, and the lightning arrester element is connected by the tap lead wire. (1) The lightning protection element has almost the same potential as the tap lead wire.
Only the insulation dimensions between the windings and tanks required by the tap lead wire are required.

(2) It is possible to minimize an increase in the insulating dimension between the winding, the tank and the metal structure.

(3) Since the electric field concentration at both ends of the lightning protection element can be relaxed, the shields for relaxing the electric field attached to both ends of the lightning protection element can be made compact.

(4) It is not necessary to increase the size between the shield at both ends of the lightning protection element, the winding, and the tank.

(5) If a plurality of lightning protection elements are alternately sandwiched between the tap lead wires and fixed between the left and right sides, the lightning protection element can be firmly fixed without requiring any special fixing means. .

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a structure for installing a lightning arrester of a transformer with a built-in lightning arrester according to the present invention.

FIG. 2 is a side view of a portion of the transformer with a built-in lightning arrester according to the present invention in which a lightning arrester is sandwiched between tap lead wires.

FIG. 3 is a plan cross-sectional view of a portion in which a lightning arrester is sandwiched between tap lead wires of a lightning arrester-equipped transformer of the present invention.

FIG. 4 is a plan view of a portion of the transformer with a built-in lightning arrester, in which a lightning arrester is sandwiched between tap lead wires.

FIG. 5 is a conceptual connection diagram of a high-voltage winding of a tap switching transformer under load to which a lightning protection element is added.

FIG. 6 is a conceptual connection diagram of a tap-changing autotransformer with load, to which a lightning arrester is added.

FIG. 7 is a plan view showing an installation structure of a lightning protection element of a conventional transformer with a built-in lightning protection element.

[Explanation of symbols]

 1 ... Iron core 2 ... Winding 2A ... Tap winding 3 ... Load tap switching device 4 ... Tap lead wire 5 ... Cleat 6 ... Tank 7A, 7B ... Shield LA ... Lightning arrester

Claims (2)

[Claims] 1. A transformer in which the tap winding and a tap switching device under load are connected by a tap lead wire drawn from a tap winding wound around an iron core, and a lightning arrester element is connected to both ends of the tap winding. In a transformer with a built-in lightning protection element, the contents of which are stored inside a tank, the lightning protection element is fixed by being sandwiched between the tap lead wires and connected to tap lead wires connected to both ends of the tap winding, respectively. A transformer with a built-in lightning protection element. 2. The lightning protection device built-in transformer according to claim 1, wherein the lightning protection device is sandwiched and fixed between a plurality of tap lead wires that are alternately distributed to the left and right sides.