EP3048623B1

EP3048623B1 - Transformer with reduced height, volume and weight

Info

Publication number: EP3048623B1
Application number: EP15171404.5A
Authority: EP
Inventors: Gökhan Kalkan; Abdullah Cicibas; Kutay ÇITIR; Ibrahim Yildiz
Original assignee: Balikesir Elektromekanik Sanayi Tesisleri AS
Current assignee: Balikesir Elektromekanik Sanayi Tesisleri AS
Priority date: 2015-01-20
Filing date: 2015-06-10
Publication date: 2017-11-22
Anticipated expiration: 2035-06-10
Also published as: PL3048623T3; EP3048623A1

Description

TECHNICAL FIELD

The invention relates to transformers used in electrical energy systems.
The invention particularly relates to transformers which are used to increase, reduce or regulate the voltage level in electrical energy systems, with reduced total height, weight and volume by changing the location of the commutator (NLTC: No Load Tap Changer).

STATE OF THE ART

Transformer is an electromagnetic tool which connects two or more electric circuit to each other with electromagnetic induction. It transfers the electrical energy from one electric circuit to another electric circuit by means of electromagnetic field. Transformers are the machines that make the required changes in voltage and current values for a specific power of electric energy.
Transformer essentially consists of two windings positioned closely to each other and a magnetic core. If voltage is applied to one of the windings, voltage induces at the other terminal. The current impressed by applying the voltage creates a magnetic field around the winding. This magnetic field creates a voltage on the other winding which is positioned closely, by completing its magnetic circuit through the core.
In general terms, transformers are used to decrease or increase the magnitude of electrical voltage or current in an electrical circuit. Essentially transformers transfer energy from one electrical circuit to another with electromagnetic induction. Changing of voltage magnitude is required in order to transfer electric energy to places remote from its generation area. The weight of the cables needed for transmission is considerably decreased by increasing the voltage, for example up to 230.000 volt or more. Thus, economical improvements like the necessary transmission towers and other infrastructures are achieved.
Transformers are composed of the main components; core, windings, transformer tank, tank cover and commutator. In the existing system, commutator is placed between the upper part of the core and the tank cover. There is no electrical voltage on the tank cover and the core during test and operation conditions. During test and operation conditions, there is an electrical voltage on the commutator connected to the windings. This situation causes following problems:

The fact that the commutator with voltage is between the core and the tank cover without voltage, increases the height of the transformer tank in the axial direction.
Due to the fact that the commutator, which is a component with voltage, is placed between the core and the tank cover, which are two components without voltage, these structures should be insulated from each other with proper materials and methods. As insulation material, low-viscosity transformer oil is used. The insulation structure used in the existing system is inefficient and of high-cost due to the distances.
Depending on the increasing tank height, volume of the tank increases. The increase in the volume of the tank which is filled with low-viscosity transformer oil increases the amount of the transformer oil used.
Due to the increasing volumes of transformer tank and low-viscosity transformer oil, total weight of the transformer increases.
The increase in the total amount of material of the transformer also increases the total cost of the transformer.

Moreover, depending on the increasing demand on yearly basis for electrical power in residential areas; power, size and weight of transformers also increase. At the point of replacing existing transformers with new transformers with higher power values; there are some problems in terms of sizes in assembling new transformers to the confined transformer cells designed in accordance with the existing system.
In the state of the art, no document has been encountered in the novelties made in transformers for resolving the problems mentioned above.
Consequently, there is an intention for bringing forth novelties in transformers in terms of size and weight, thus there is a need for new embodiments to eliminate the abovementioned disadvantages and bring solutions to the existing systems.

OBJECT OF THE INVENTION

The present invention relates to transformers which meet the abovementioned requirements, eliminate all the disadvantages and bring some additional advantages.
The object of the invention is to provide solution to the problems mentioned in existing technique by changing the position of the commutator.
An object of the invention is to enable reducing the axial height of the transformer tank by decreasing the distance between the core and the tank cover, thus to decrease transformer's height.
Another object of the invention is to prevent insulation problems and costs by changing the position of the commutator, which is the component carrying voltage between the core and the tank.
Another object of the invention is to enable decreasing the amount of the low-viscosity transformer oil used by decreasing the tank volume, depending on the tank height.
Another object of the invention is to enable decreasing the total weight by decreasing the tank volume and the low-viscosity transformer oil used.
Another object of the invention is to enable decreasing the total cost by using less material in the production of the transformer.
Another object of the invention is to allow replacing the existing transformers in the confined cells with transformers that have higher rating capacity.
In order to fulfil all the advantages that are mentioned above and will be understood from detailed descriptions below, the present invention relates to a transformer which is used to increase, decrease or regulate the voltage level in electrical energy systems, having a core as magnetic body, windings that change the electrical voltage, a tank holding the low-viscosity transformer oil together, a tank cover covering the tank and a commutator fixing the output voltage; and it has an embodiment wherein the commutator is positioned between the core and the tank, at the upper yoke side of the core.
The structural and characteristic features and all the advantages of the present invention will be understood more clearly thanks to the figures below and the detailed description written with reference to those figures. Therefore, the evaluation needs to be done by taking said figures and the detailed description into consideration.

BRIEF DESCRIPTION OF THE FIGURES

The present invention should be evaluated with the figures described below to ensure the best understanding of the embodiment and advantages together with the additional components of the invention.

Figure 1 is a perspective outer view of the transformer according to the invention.
Figure 2 is the front view of the transformer according to the invention.
Figure 3 is the side view of the transformer according to the invention.
Figure 4 is the perspective inner view of the transformer according to the invention.

REFERENCE NUMBERS

10. Transformer
11. Core
12. Winding
13. Tank
14. Tank cover
15. Commutator
16. Insulating component

DETAILED DESCRIPTION OF THE INVENTION

In this detailed description, the preferred embodiments of the transformer (10) according to the invention will be explained for a better understanding of the subject without any limiting effect.
The present invention relates to a transformer (10) which is used to increase, decrease or regulate the voltage level in electrical energy systems, having a core (11) as magnetic body, windings (12) that change the electrical voltage, a tank (13) holding the low-viscosity transformer oil together, a tank cover (14) covering the tank (13) and a commutator (15) fixing the output voltage; wherein the commutator (15) is positioned between the core (11) and the tank (13), at the upper yoke side of the core (11).
The transformer (10) shown in the figures essentially comprises a core (11), windings (12), tank (13), tank cover (14) and commutator (15).
The core (11) is the structure that magnetically couples the primary and secondary windings (12) without electrical connections, on which the magnetic flux flows and which serves as a mediator for energy transformations. There is no electrical voltage thereon in testing and operating conditions. It is manufactured from silicon alloy metal sheets.
Windings (12) change the electrical voltage according to the number of turns. They are the structures with various shapes that increase, decrease or regulate the system voltage depending on the number of turns. They are wrapped around the legs of the core (11). There is electrical voltage thereon during test and operation conditions. They are manufactured from copper or aluminium material.
Transformer tank (13) holds low-viscosity transformer oil together. It is a hollow metal structure which holds the low-viscosity transformer oil that is used as cooling material in transformers having oil-type cooling system and has low-viscosity. There is no electrical voltage thereon during test and operation conditions. It is manufactured from steel plates.
Tank cover (14) is the metal plate which has protection devices thereon and covers the upper surface of the transformer tank (13). It is manufactured from steel plate.
Commutator (15) is the mechanical structure which fixes the voltage level adjusted by the number of turns of the primary and secondary windings by changing the number of turns. Commutator (15) is connected with the windings (12) and tank cover (14).
In the present invention, commutator (15) is carried from the intermediate area of the core (11) and tank cover (14) to the intermediate area of the core (11) upper yoke and transformer tank (13). Commutator (15) is positioned in the side of the tank (13) and there is an insulation component (16) between the commutator and the core (11) upper yoke. Mentioned insulation component (16) is an insulating material made of psp and its derivatives. Carrying the commutator (15) with electrical voltage between the core (11) upper yoke and the transformer tank (13) does not constitute electrical problem due to the presence of enough distance in radial direction and of the insulating component in this area (16). Therefore, even though the distance in axial direction is reduced in the new system, this state doesn't cause any electrical problem.
Carrying the commutator (15) with electrical voltage thereon enabled the core (11) and tank cover (14) without electrical voltage thereon to get closer and decreased the transformer tank (13) height. Decreasing the axial distance between the core (11) and the tank cover (14) also decreased the height and volume of the transformer tank (13). Due to the decreasing volume of the tank (13), the amount of the low-viscosity transformer oil, which is used as cooler and insulator, is also decreased.
The decreased transformer tank (13) volume and the decrease in the amount of the transformer oil used, significantly reduced the total cost and weight of the product.
By this invention, while replacing the existing transformers with new transformers having higher power values, new transformers will be enabled to be produced in sizes to fit into the transformer cells designed according to the existing system.

Claims

A transformer (10) which is used to increase, decrease or regulate the voltage level in electrical energy systems, having a core (11) as magnetic body, windings (12) that change the electrical voltage, a tank (13) holding the low-viscosity transformer oil together, a tank cover (14) covering the tank (13) and a commutator (15) fixing the output voltage; characterized in that the commutator (15) is positioned between the core (11) and the side wall of the tank (13), at the upper yoke side of the core (11), and an insulating component (16) is positioned between the upper yoke of the core (11) and the commutator (15), which enables insulation between the commutator (15) and the core (11).