CN102568780B - Lead wire connection structure for transformer - Google Patents

Abstract

The invention relates to a transformer accessory, in particular to a lead wire connection structure for a transformer. The lead wire connection structure for the transformer is characterized by comprising a first joint, a second joint and a coil outlet lead wire, wherein a wire nose is welded at the upper end of the coil outlet lead wire; the second joint has a three-way shape; one end of the second joint is welded with a second copper pipe lead wire, and the other two ends of the second joint are connected with the first joint and the wire nose respectively through bolts; the other end of the first joint is welded with a first copper pipe lead wire; crepe paper is filled in non-circular parts or grooves of the connection parts of the components; and the peripheries of the components are sequentially wrapped with aluminum and platinum crepe paper, the crepe paper and a high network band from inside to outside. The lead wire connection structure for the transformer has the advantages of safety, reliability and high practicability, has a great significance for guaranteeing the insulation intensity of the transformer, and is favorable for application to ultrahigh voltage and high capacity power transformers; and weld joints are easy to clean, and partial discharging is reduced.

Description

A transformer lead connection structure

(1) Technical field

The present invention relates to a transformer accessory, in particular to a transformer lead connection structure.

(2) Background technology

At this stage, the demand for high-voltage and ultra-high-voltage transformers is increasing day by day. Among these transformers, in order to reduce the insulation distance, reduce partial discharge, and weaken the skin effect (under the condition of certain frequency and lead unit resistance, the skin effect coefficient C and copper tube Proportional to the thickness t of the copper tube and inversely proportional to the diameter of the copper tube), reducing the temperature rise of the lead wire and effectively utilizing raw materials, the number of transformers using copper tubes as the lead wire also increases accordingly, but the copper tube is not connected like copper stranded wire and copper So flexible and convenient. If the previous copper tube connection method is used, that is, welding between the coil head lead and the joint is required on the body, and welding between the two ends of the joint and the copper tube lead is also required, and welding, cleaning welding slag, smooth electrodes, installation and disassembly, etc. It is all inconvenient to operate, and the high temperature produced when welding on the device body and the moisture applied by cooling will cause harm to other insulations of the transformer, and are also unfavorable for the improvement of the insulation strength and service life of the transformer.

(3) Contents of the invention

In order to make up for the deficiencies of the prior art, the present invention provides a safe, reliable and practical transformer lead wire connection structure.

The present invention is achieved through the following technical solutions:

A transformer lead connection structure, characterized in that it includes a first joint, a second joint, and a coil lead wire, the upper end of the coil lead wire is welded with a wired lug, the second joint is a three-way joint, and one end of the second joint is connected to the second copper pipe lead wire welding, the other two ends are respectively connected with the first joint and the wire lug by bolts, the other end of the first joint is welded with the first copper pipe lead wire, the connection parts of the above-mentioned components are not round or the grooves are filled with crepe paper, the above-mentioned The periphery of each component is wrapped sequentially with aluminum foil crepe paper, crepe paper and high-network belt from inside to outside.

The welding method of the coil outlet lead wire and the wire lug is cold pressure welding, and the brazing method of phosphorus copper welding rod is used for welding between the second joint and the second copper pipe lead wire and between the first joint and the first copper pipe lead wire.

The beneficial effects of the transformer lead connection structure of the present invention are: the structure is simple, it can be operated on the console, the operation is convenient, safe and reliable, the practicability is strong, and the possibility of welding slag falling into the body of the transformer lead during welding and the possibility of welding The high temperature caused by the process and the water applied by the process will damage the whole or part of the transformer. It is easy to clean the weld seam, which is very important for reducing partial discharge and ensuring the insulation strength of the transformer. capacity power transformers.

(4) Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings.

Fig. 1 is a cross-sectional view of a conventional transformer lead connection structure;

Fig. 2 is a cross-sectional view of the transformer lead connection structure of the present invention.

In the figure, 1 first joint, 2 second joint, 3 coil lead wire, 4 wire nose, 5 second copper pipe lead wire, 6 first copper pipe lead wire, 7 aluminum foil crepe paper, 8 crepe paper, 9 high network belt, 10 bolts, 11 third joints, 12 fourth joints.

(5) Specific implementation methods

Accompanying drawing is a kind of specific embodiment of the present invention. This embodiment includes a first joint 1, a second joint 2 and a coil lead wire 3, the upper end of the coil lead wire 3 is welded with a wired nose 4, the second joint 2 is a three-way joint, and one end of the second joint 2 is connected to the second copper pipe lead wire 5 Welding, the other two ends are respectively connected to the first joint 1 and the lug 4 through bolts 10, the other end of the first joint 1 is welded to the first copper pipe lead 6, the connection parts of the above components are not round or the grooves are filled There is crepe paper 8, and the periphery of the above-mentioned components is wrapped with aluminum foil crepe paper 7, crepe paper 8 and high-network tape 9 from the inside to the outside. Both the lead wire 5 of the second copper pipe and the first joint 1 and the lead wire 6 of the first copper pipe are welded by the brazing method of phosphor copper welding rod.

From the original coil head lead 3 and the third joint 11 need to be welded on the device body, and the two ends of the fourth joint 12 are respectively welded with the first copper pipe lead 6 and the second copper pipe lead 5 to become the wire lug 4 and the transformer coil. The leading wire 3 is connected by cold pressure welding, the first joint 1 and the first copper pipe lead 6 are welded by the brazing method of phosphor copper welding rod, the second joint 2 is a three-way joint, one end of which is connected to the first joint of the transformer The two copper pipe lead wires 5 are welded by the brazing mode of phosphor copper welding rod, and the other two ends are respectively connected with the first joint 1 and the wire lug 4 through bolts 10, so as to avoid burning on the transformer body.

The lead wire of the copper pipe is brazed with phosphor copper electrode, only lap welding is allowed, and the lap area is 3 to 5 times that of the smaller end of the weldment. There are three gaps milled at the end of the copper tube for phosphor-bronze welding (evenly distributed along the circumference), do not open four, otherwise the phosphor-bronze will flow down. Use phosphorus brazing to weld the copper joints and copper pipes, fill the gap between the surface of the lead wire and the insulation with crepe paper 8, and wrap the outer aluminum foil crepe paper 7 in half, with the metal film facing inward to maintain good electrical contact with the lead wire. Splicing length is not less than 30mm, aluminum foil crepe paper 7 is not allowed to be spliced, then wrap crepe paper 8 half-fold one layer, then wrap crepe paper 8 to the required insulation thickness, and finally wrap high-network tape 9 half-ply one layer. The high-network belt 9 is produced by Dandong Hongshun Electric Manufacturing Co., Ltd. or Baoding Tianwei Power Wire Co., Ltd.

The transformer lead wire connection structure of the present invention can avoid the problem of welding on the transformer body when copper tubes are used as the transformer lead wires, facilitates cleaning of welding slag and smooth electrodes after welding, and can prevent high temperature and moisture applied during welding on the body of the transformer It is harmful to other insulation of the transformer, and it is also very convenient in assembly and disassembly. It is mainly used in the connection between copper tube leads of 110kV and above power transformers and between copper tube leads and coil outlets or copper stranded wires.

Claims (2)

1. A transformer lead connection structure, characterized in that it includes a first joint (1), a second joint (2) and a coil lead wire (3), the upper end of the coil lead wire (3) is welded with a wired nose (4), the second The second joint (2) is a three-way joint, one end of the second joint (2) is welded to the second copper pipe lead (5), and the other two ends are respectively connected to the first joint (1) and the wire lug (4) through bolts (10 ) connection, the other end of the first joint (1) is welded to the first copper pipe lead (6), the connection parts of the above-mentioned components are not round or the grooves are filled with crepe paper (8), and the periphery of the above-mentioned components is from the inside to the Aluminum foil crepe paper (7), crepe paper (8) and high-network belt (9) are wrapped in sequence on the outside. 2. The transformer lead connection structure according to claim 1, characterized in that: the welding method of the coil outlet lead wire (3) and the wire lug (4) is cold pressure welding, and the second joint (2) and the second copper pipe lead wire (5) and between the first joint (1) and the first copper pipe lead (6) are welded by brazing with phosphor copper electrodes.