JPH04278506A - Current transformer for melting snow - Google Patents

Abstract

PURPOSE:To remarkably improve the installation of work of heat generating wires, and enhance reliability, by installing a terminal box for connecting a secondary side winding with the heat generating wires, and constituting terminals so as to be able to select the heat generating wires in parallel or in series. CONSTITUTION:A current transformer 2 is divided into half isolated bodies. When the transformer is mounted on a wire 1, said bodies are combined and fixed by using bolts, and a transmission line 1 turning to the primary side penetrates the central part. A terminal box 3 has terminals u1, u2, u3, and V1, V2, V3. By suitably selecting these terminals, heat generating wires can be connected in series or in parallel. Thereby the connection work of the heat generating wires is very simplified, and insulation and waterproofing effect can be made sure by tight sealing with a filler.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a snow melting device that winds a heating wire around a power transmission line and generates heat in the heating wire when ice and snow accrete, melting the ice and snow and causing it to fall and be removed. The present invention relates to a novel current transformer for snow melting that is useful as a power source.

0002

[Prior Art] When there is ice and snow on power transmission lines, the snow falls all at once, causing sleet jumps, or during snowstorms, extremely large abnormal vibrations such as galloping occur, which can cause short circuits between phases. Furthermore, if the accumulated snow rotates and grows and becomes a pipe of snow, the weight of the power transmission line will increase significantly, which may lead to not only wire breakage accidents due to abnormal tension but also the collapse of steel towers.

[0003] Furthermore, if there is ice and snow on a power transmission line and the next day it is sunny, there is a risk that the ice and snow will melt at the interface and fall as large snowflakes, damaging structures and crops beneath the line. There is also.

[0004] For this reason, various proposals have been made so far as means for preventing the accumulation of ice and snow on electric wires. The one shown in FIG. 8 is one example, in which rings 10, 10 are attached to the outer periphery of the electric wire 1 at appropriate intervals. Although the rings 10, 10 are intended to prevent snow from rotating and growing, the reality is that the snow does not fall as expected.

[0005] Furthermore, since twisting of electric wires can cause snow to grow, methods have been proposed in which a weight is attached to the electric wires to prevent the electric wires from twisting, but this method also does not work as expected. The reality is that they are not available. Therefore, as shown in Fig. 5, a current transformer 2 is attached to the electric wire 1, and the transmission current of the electric wire 1 is divided by the secondary coil of the current transformer 2, and this is used as a power source to generate heat in the heating wire 5, which is directly connected to the electric wire 1. A proposal was made to melt the snow that had adhered to the area, and it attracted attention.

[0006]

[Problems to be Solved by the Invention] In the above, in order to connect the current transformer 2 and the heating wire 5, as shown in FIG. 51
Either they are connected on-site by compression or soldering, and then insulated and waterproofed, or they are connected directly from the secondary winding as shown in Figure 7 without making such connections. A method has been adopted in which the current transformer 2 and the heating wire 5 are integrated by pulling out the heating element 5 of a predetermined length.

However, in the case of the above-mentioned snow melting equipment, the connection by compression or soldering has extremely poor workability, and even after insulation and waterproofing, its reliability is questionable, and corona discharge at the connection part is a problem. There are also problems with isoelectric properties.

In the case where the current transformer 2 and the heating wire 5 are integrated, since the heating wire 5 is already attached to the current transformer 2, it is not easy to wrap the heating wire 5 around the electric wire. In addition, because the length of the heating wire is set to a certain length from the beginning, there are significant restrictions on the capacity of the current transformer, the amount of heat generated by it, and the length of the snow melting section.
There is a problem in that it cannot be used anywhere other than in specially designated countermeasure locations.

The purpose of the present invention is to solve the problems of the prior art as described above, to greatly improve the workability of installing the heating wire, to increase its reliability, and to improve the length or length of the heating wire. The present invention aims to provide a novel current transformer for snow melting that can change its calorific value and has extremely flexible applications.

0010

Means for Solving the Problems The present invention provides a current transformer that is divided so as to pass through a primary power transmission line and has its own secondary winding. It is equipped with a terminal box that connects the side winding and the heating wire,
Furthermore, the terminals of the terminal box are configured so that the heating wires can be selectively connected in parallel or in series.

[0011]

[Function] If the current transformer is provided with a terminal box, the current transformer and the heating wire can be easily connected with the terminal, and excellent workability can be maintained even in field work.

[0012] Furthermore, if the heating wires can be selectively connected in parallel or in series by selecting the terminals of the terminal box, the method of connecting the heating wires can be freely changed, thereby reducing the amount of heat generated. It is possible to take advantage of the great advantage of being able to freely select the length of the heating wire.

[0013]

[Examples] The present invention will be specifically described below with reference to Examples.

FIG. 1 is an explanatory diagram showing a state in which a snow melting current transformer 2 according to the present invention is attached to an electric wire 1, and heating wires 5A and 5B are connected to the current transformer 2 at a terminal box 3. FIG. 2(a) is an explanatory diagram of a specific configuration of the current transformer 2 viewed from the longitudinal direction of the electric wire.

The current transformer 2 is divided into halves, which are connected to the electric wire 1.
When installing the halves on the power transmission line 1, as shown in the figure, assemble and fix the halves with bolts, and connect the central part to the power transmission line 1, which will be the primary side.
is forced to penetrate. 3 is a terminal box which is a feature of the present invention, and has terminals u1, u2, u3 and v1, v2, v3, respectively. Also, Figure 2(b)
is an explanatory diagram of the same as seen from the radial direction of the wire. In the figure, a filler 4 is shown, but this is done after connecting and fixing the heating wire 5A or 5B to each of the above-mentioned terminals.
It is filled and hardened for insulation and waterproofing. Such a filler 4 can be easily filled and hardened using a certain mold even on site.

FIG. 3 is an explanatory diagram showing the wiring state of the current transformer 2 according to the present invention configured as described above.

While the secondary coil has terminals u1, v1, other terminals u2, u3 and v2, v3 are arranged as shown in the figure, and by appropriately selecting these terminals, the heating wire 5A or 5B can be connected. can be connected both in series and in parallel.

That is, FIG. 4(a) shows how the heating wires 5A and 5B shown in FIG. 1 are connected in parallel, and FIG. 4(b) shows how the heating wires 5A and 5B are connected in series. It shows. The capacity of the current transformer 2 is determined by the power flow of the power transmission line, the resistance value of the heating element, its length, and the amount of heat generated, but these are easily affected by weather conditions and are extremely difficult to standardize. . Therefore, by connecting the heating wires 5A and 5B in parallel or in series according to the capacity of the current transformer, it is possible to freely combine the countermeasure length and heat output, and the snow melting efficiency due to heat generation is improved. This makes it possible to further improve the

In the above embodiment, an example was shown in which the terminal box was installed on both sides of the current transformer, but it goes without saying that the terminal box may be installed only on one side. In addition, the terminals inside the terminal box can of course be freely selected depending on the needs, such as the commonly used screw-fastening method, crimping method, or insertion method.
It may be selected appropriately considering the workability and the like.

[0020]

[Effects of the Invention] As described above, with the current transformer according to the present invention, it is extremely easy to connect the heating element, and the insulation and waterproofing effects can be reliably exhibited by sealing with the filler. Since the heat output and the length of snow melting measures can be selected according to the capacity of the current transformer, it is possible to standardize current transformers from the beginning and mass-produce them, resulting in a significant cost reduction effect. It is also possible to expect great economic benefits.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing how a current transformer according to the present invention is attached to a power transmission line and a heating line is connected.

FIG. 2(a) is an explanatory diagram of an embodiment of the present invention viewed from the longitudinal direction of the electric wire, and FIG. 2(b) is an explanatory diagram similarly viewed from the radial direction of the electric wire.

FIG. 3 is a schematic explanatory diagram showing a wiring situation in an embodiment according to the present invention.

FIG. 4(a) is an explanatory diagram showing a case of parallel connection, and FIG. 4(b) is an explanatory diagram showing a case of series connection.

FIG. 5 is an explanatory diagram showing how a heating wire is attached to an electric wire using a conventional current transformer.

FIG. 6 is an explanatory diagram showing a connection situation between a conventional current transformer and a heating wire.

FIG. 7 is an explanatory diagram showing another conventional configuration example of a current transformer and a heating wire.

FIG. 8 is an explanatory diagram illustrating a snow accretion prevention device in which a ring is attached to an electric wire.

[Explanation of symbols]

1 Electric wire 2 Current transformer 3 Terminal box 4 Filling material 5A, 5B Heating wire

Claims (2)

[Claims] Claim 1: A current transformer that is divided so that it can pass through a primary power transmission line and has its own secondary winding, the current transformer having a secondary winding and a heating wire. A current transformer for snow melting that is equipped with a terminal box to connect. 2. A current transformer for snow melting according to claim 1, wherein the terminals in the terminal box are configured so that the heating wires can be selectively connected either in parallel or in series.