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Core Type Transformers

ultimate guide to core type transformer

A transformer is an innovative invention in electrical engineering that transfers electricity from one circuit to another without physically touching or changing its frequency, phase, or any other component of the machine. It is by far the most important part of all grid equipment. Different types of transformers are used in different situations. The winding and insulation assembly in the core structure of the transformer is relatively easy, and this structure is often used in power transformers.

Daelim has a fast and efficient production capacity and a professional marketing team. Our main products include 110kV transformers, 220kV transformers, dry-type transformers,oil-immersed transformers, amorphous alloy transformers, etc. Daelim has more than 20 years of experience in the transformer field of production and export experience. And all products are tested by the National Transformer Quality Supervision and Inspection Center. Our products are exported to the United States, Canada, Australia, New Zealand, and other countries and regions.

Pad-mounted Transformer

Single phase and three phase pad mounted transformer

Small-substastion Transformer

Rated Capacity: Up to 20MVA; Rated Voltage: Up to 44KV;

Single Phase Pole Mounted Transformer

Frequency: 50/60Hz; Rated Power Rating: 5~333kva

Oil Immersed Power Transformer

Rated voltage:Up To 400 kV Rated Power: 10MVA-300MVA

Table of Content

What is a core transformer?

core transformers
core transformers

The core of a shell transformer is wound around the windings, while the windings of an iron-core transformer are wound around the core. We will discuss core transformers here. Core transformers are also called cylindrical or core winding transformers because their windings are arranged in concentric coils.

In a shell-type transformer, the low-voltage winding and the high-voltage winding are placed in a sandwich form, so it is also called a sandwich or disc winding transformer.

Core transformer structure

core transformer structure
core transformer structure

First of all, any type of transformer is mainly composed of three parts, namely the core, the primary winding, and the secondary winding. These three parts form the core part of the transformer. The core part is also a very important part of the transformer, which provides a continuous magnetic circuit with a minimum air gap. This is made from plastic-coated steel sheets that are heavily coated with silicon. And the laminate also maintains increased permeability and minimal hysteresis losses.

In order to reduce the loss caused by eddy current to the transformer, the steel plate of the transformer will be protected with a light coating core polishing material or an oxide layer on the surface. The width of the stacks varied from 0.35 mm at 50 Hz to 0.5 mm at 25 Hz.

In addition, in order to avoid a minimum gap between layers, steel plates are placed in sequence in the transformer for protection, and these staggering joints are called tile joints. There are two types of transformer structures: core type and shell type. Here, we are discussing the structure of the core transformer. In a core-type transformer, most of the core section within the transformer is protected by windings. Usually, the core part of the core-type transformer is rectangular, and the coil is rectangular or circular.

Round or cylindrical coils are often used for winding in large core type transformers because the mechanical capacity of a circular shape coil is greater than that of a rectangular shape coil. These windings are protected by helical layers, which have multiple layers of protection and are shielded from each other using paper, cloth, cooling channels or mica plates, etc. To minimize flux leakage, the two windings are placed one after the other using a highly insulated cylinder.

What are the characteristics of core transformers?

The core of the core transformer is generally rectangular, the coil is circular or rectangular, and the winding is located on the opposite side of the core.

According to the power supply used, transformers are mainly divided into single-phase and three-phase transformers.

Air core transformer. This is a core type transformer in which the windings are wound on non-magnetic strips.

Core transformer. This is a core type transformer in which the windings are wound around the core.

Single phase core transformer vs Three-phase core transformer

three phase core transformer
three phase core transformer

Three-phase transformers have three legs and single-phase transformers have two legs. The structural feature of the three-phase core transformer is that the three-phase magnetic circuits are connected together, and the magnetic flux of each phase takes the other two-phase magnetic circuits as its own circuit. Compared with shell-type transformers, core-type transformers have the advantages of fewer consumables, low prices, small footprints, and simple maintenance, and are the most widely used.

However, in large-capacity and other giant transformers, in order to facilitate transportation and reduce the reserve capacity, three-phase group transformers are often used. The three-phase transformer inputs three-phase symmetrical AC power and output three-phase symmetrical AC power. It can provide three-phase power for industrial electrical equipment that requires three-phase power, such as three-phase AC asynchronous motors, etc. Electric household appliances, such as light bulb color TVs, etc., provide single-phase power supply three-phase four-wire power supply mode.

single phase core transformer
single phase core transformer

The three-phase transformer inputs three-phase symmetrical AC power and output three-phase symmetrical AC power. It can provide three-phase power for industrial electrical equipment that requires three-phase power, such as three-phase AC asynchronous motors, etc. Electric household appliances, such as light bulb color TVs, etc., provide single-phase power supply three-phase four-wire power supply mode.

Three coils are required on the high and low voltage sides of a three-phase transformer, and the three coils on the high and low voltage sides are connected according to certain rules. This is the connection group of the transformer. There are many types, such as Yyn0, Dyn11, Yd11, etc., which can be Users provide the power they need. On the other hand, the high and low voltage sides of the single-phase transformer only need one coil, which can be connected to the power supply and the load respectively.

In other respects, the core of a three-phase transformer is a flat “Japanese” type, which provides three magnetic circuits for three-phase electricity, and the core of a single-phase transformer is a “mouth” type, which has only one magnetic circuit.

What are the different applications of core transformers?

Different types of transformers are used in different places. There are also different functions. Power transformers are often used to increase the voltage within the distribution network Distribution transformers are primarily used to reduce the voltage that is distributed to commercial and residential customers.

Core Transformers the shape of the core of the transformer can be selected according to the rating of the transformer, and different types of laminations are used.  Because it is difficult for us to bend thick conductors into rectangles or squares. Therefore, the best choice for high-power transformers is cylindrical windings.  All in all, square or rectangular cores are economical for small transformers.

Types of core type transformer

Transformers can be assembled into a variety of different types. Different types of transformers are used in different places. Such as single-phase transformers, three-phase transformers, the two separate electrical windings of the transformer are not electrically connected from one side to the other, but conduct electricity through electromagnetic flux. And transformers have many windings or coils wound on both the primary and secondary side. The various primary sides are sometimes referred to as center taps and can also be seen on the secondary side.

Core type transformers service

Daelim Electric Co., Ltd. adheres to the concept of “people-oriented, technology and development, quality and market, and brand benefit”; strictly adheres to the business philosophy of “honesty and trustworthiness”: and actively develops brand enterprises and strives to build a world-class transformer. Customers provide high-quality products and good after-sales service. Thanks for using the products of Daelim Electric Co., Ltd,our company commits to product quality after-sales service as follows for you relying on our products:

  1. All transformer products of DaelimElectric Co., Ltd. are produced in strict accordance with international standards.
  2. Daelim transformers not only have SGS, CESI, CSA, CNAS, and other transformer test reports, but also UL/cUL, IEEE and other certificates.
  3. For the core transformers, Daelim has after-sales service teams in the United States, Canada, Ecuador, and other regions.
  4. The delivery time of Daelim transformers is usually 8-15 weeks, and the production capacity is strong.

Welcome to inquiry at any time.

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Hello, I am Bin, General manager of Daelim which is a leading transformer manufacturer. If you have problems when you are looking for the equipment, what you need to do is tell us.