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The power transformer is an electromagnetic component. It is static electrical equipment that transforms alternating current and is widely used in almost all electronic products. It is used to change the power generated by the power station to high voltage and reduce the loss during transmission, so as to facilitate long-distance power transmission.

The function of the power transformer:

The functions of the power transformer can be divided into the following three main functions: voltage conversion, power transmission, and insulation isolation.

Principle of power transformer:

The principle of the transformer is the electromagnetic induction to transmit signals from one circuit to another circuit; the coil connected to the power supply, which receives AC power, called the primary winding; the coil connected to the load, which sends AC power, is called the secondary winding.

Structure of power transformer:

The structure of the transformer is composed of iron core and winding. The main magnetic circuit of the transformer is composed of an iron core, and the iron core is divided into two parts of the iron core column and the horizontal piece. The circuit part of the transformer is formed by winding the enameled original wire or double-wire insulated flat wire.

Classification of power transformers:

According to usage: power transformer; special transformer; instrument transformer; test transformer.

Divided by winding form: double winding transformer; three winding transformer; autotransformer.

According to the form of iron core: core transformer; bright transformer; amorphous alloy transformer.

Divided by the number of phases: single-phase power transformer; three-phase power transformer.

Divided by cooling method: dry-type power transformer; oil-immersed power transformer.

According to the size of the transmission power: 10KVA above is high power; 10KVA~0.5KVA is medium power; 0.5KVA~25VA is low power; 25VA below is micropower.

Purpose of power transformer:

The power transformer can be stepped up or stepped down. When implementing the long-distance transmission of power, the power transformer is used to increase the voltage to the point of use and then reduce the voltage to the required voltage amplitude. The iron core in the transformer can produce an alternating magnetic field.

As a cross-border B2B platform, ESGCC Global has many related products. Here are some examples:

500kV Power Transformer,120MVA-720MVA, Three-Phase, Double Windings Off-circuit Tap-changing Power Transformer

35kV Power Transformer/KEMA certificate/LEEEC

If you want to know more information, you can visit https://g.esgcc.com.cn/products/AC-Transformer.html

ESGCC Global, built by State Grid Electronic Commerce Co., Ltd., is the cross-border B2B digital trading platform for power industry. The platform has gathered nearly 80,000 electrical equipment manufacturers to provide over 170,000 cost-effective electrical equipment products with international quality selection, helping global users of power industry to achieve smart online procurement with one-stop trading service.

1. power cable

The power cable is used to transmit and distribute high-power electrical energy in the main line of the power system, including power cables of various voltage levels and insulations ranging from 1 to 330KV and above.

According to voltage levels, power cable can be divided into low-voltage cables, medium-voltage cables, and high-voltage cables. According to the insulation conditions, it is divided into plastic insulated cables, rubber insulated cables, mineral insulated cables, etc.

2. Overhead insulated cable

Overhead cables are also very common, and their characteristic is that they have no sheath. Many people have three misunderstandings about this type of cable.

First, its conductor is not only aluminum but also copper conductors (JKYJ, JKV) and aluminum alloys (JKLHYJ). Now there is also steel core aluminum stranded overhead cable (JKLGY).

Second, it is not only single-core, the common ones are generally single-core, but it can also be stranded with several conductors.

Third, the voltage level of overhead cables is 35KV and below, not 1KV and 10KV.

3. Control Cable

The structure of this type of cable is similar to that of a power cable. The feature is that it only has a copper core instead of an aluminum core cable. The conductor cross-section is small and the number of cores is large.

It is suitable for stand-alone control or unit equipment control of power stations, substations, mines, petrochemical enterprises, etc., with AC rated voltages of 450/750V and below.

4. Special cables

Special cables are cables with special functions, including flame-retardant cables (ZR), low-smoke and halogen-free cables (WDZ), fire-resistant cables (NH), explosion-proof cables (FB), water-blocking cables (ZS), etc.

Flame-retardant cables (ZR), low-smoke halogen-free cables (WDZ): mainly suitable for important power and control systems. When the line encounters a fire, the cable can only burn limitedly under the action of the external flame, and there are few harmful gases (halogen) in the smoke.

When the external flame disappears, the cable can be extinguished by itself, so that minimize the fire damage to the human body and property. Therefore, this kind of cable is widely used in important places such as petrochemical, metallurgy, high-rise buildings, and densely populated places.

As a cross-border B2B platform, ESGCC Global has many related products.

Fire-Proof and Explosion-Proof Device For Cable Joint (Intelligent Type)

New Servo Cable

If you want to know more about electrical cables, you can visit https://g.esgcc.com.cn/products/Cable.html

ESGCC Global, built by State Grid Electronic Commerce Co., Ltd., is the cross-border B2B digital trading platform for power industry. The platform has gathered nearly 80,000 electrical equipment manufacturers to provide over 170,000 cost-effective electrical equipment products with international quality selection, helping global users of power industry to achieve smart online procurement with one-stop trading service.

Wires and electrical cables are essential building materials for house decoration. In modern homes, wires and cables are the most common current conductors in the family. Many people are confused about the difference between wires and cables. Both are composed of wires, but their structures are different.

The first difference between wires and electrical cables

The first difference between wires and electrical cables is that wires can be used to transmit electrical energy. They can also be used as components and connecting wires for the manufacture of motors and electrical appliances. They are generally made of copper, aluminum, etc.; while electrical cables are mainly used for communication and electricity, so cables are also divided into communication cables, power cables, control cables, etc. Cables are generally not used for the manufacture of motors, but for large-span overhead lines.

The second difference between wires and electrical cables

The wire is a conductive metal wire used to carry current. It has a variety of forms such as solid, stranded, and foil. The size of the wire is small and the structure is simple; while the cable is composed of one or more mutually insulated conductive cores, which formed in the hermetic sheath. The size of the cable is larger and the structure is more complicated.

Apart from the differences, let’s take a look at the standards of wires and electrical cables. The production of wires and cables needs to meet national standards, otherwise, there will be safety hazards. The production standard of the wire is that it must reach the specified load voltage to ensure safety. In addition, the wire should also have good electrical conductivity, mechanical properties, and thermal properties. The material of the wire must also have corrosion resistance and weather resistance, so as to ensure the service life of the wire; the standards of cables and wires are similar, the main emphasis is on safety issues, which are related to the use of raw materials and the continuity of production standard. Besides, wires and cables have relevant standards for the use of raw materials and the continuity of production.

As a cross-border B2B platform, ESGCC Global has many related products.

Mid-voltage Power Cable

Copper conductor XLPE insulated PVC sheathed power cable VJV-8.7/10kv-1 * 120

High Voltage Power Cable

If you want to know more about electrical cables, you can visit https://g.esgcc.com.cn/products/Electric-Cable.html

ESGCC Global, built by State Grid Electronic Commerce Co., Ltd., is the cross-border B2B digital trading platform for power industry. The platform has gathered nearly 80,000 electrical equipment manufacturers to provide over 170,000 cost-effective electrical equipment products with international quality selection, helping global users of power industry to achieve smart online procurement with one-stop trading service.

In today's wire and cable market, there are many products and production companies of different levels. However, many buyers simply regard price as the procurement standard, which breeds a market with many substandard products. So, what kind of cables are produced in accordance with national standards?

What is a national standard electrical cable?

The national standard electrical cable, literally understood, is the wire and cable produced in accordance with the national standard. Our country has clear regulations on the appearance, mechanical strength, insulation of the sheath, pressure resistance, wire resistance, and other aspects of the cable. Different cables have different national standards, mainly as follows:

Irradiation cross-linked power cable (0.6/1KV) executive standard: GB/T12706.1-2008

Medium voltage cross-linked cable (6/6KV-26/35KV) executive standard: GB/T12706.2-2008

High voltage cross-linked cable (64/110KV) executive standard: GB/T 11017-[/B]2002

Control cable (450/750V) executive standard: GB9330-88

Aluminum stranded wire and steel core aluminum stranded wire (0.6/1KV) executive standard: GB/T 1179-1999

How to identify the national standard electrical cable?

1. Ensure that the certificate of conformity is standard; find out if there is a quality system certification; if there is a factory name, site, inspection stamp, and production date; and if there are trademarks, specifications, voltages, etc. printed on the wires. It also depends on the cross-section of the copper core of the wire. The high-quality copper is bright in color. Otherwise, it is inferior.

2. You can take a wirehead and bend it repeatedly by hand. An excellent product has a soft hand feel, good fatigue resistance, and no cracks on the wire insulator.

3. Wires of good quality are generally within the specified weight range. Wires of poor quality have insufficient weight, either the length is not enough, or the copper core of the wire has too much impurity.

4. The copper core of the qualified copper core wire should be purple-red, shiny, and soft. The copper core of the shoddy copper core wire is purple-black, yellowish or white, with a lot of impurities, poor mechanical strength, and poor toughness. During the inspection, you only need to peel off the wire at one end and rub a piece of white paper on the copper core. If there is a black substance on the white paper, it means that there are many impurities in the copper core. In addition, the insulating layer of fake wires seems very thick, but in fact, most of them are made of recycled plastics. Over time, the insulating layer will age and cause leakage.

As a cross-border B2B platform, ESGCC Global has many electrical cables of good quality.

Low voltage cable

Copper core XLPE insulated PVC sheathed power cable yjv-0.6/1kv-1 * 120

Power Cable

YJV22 26/35kV 3× 400

If you want to know more about electrical cables, you can visit https://g.esgcc.com.cn/products/Electric-Cable.html

ESGCC Global, built by State Grid Electronic Commerce Co., Ltd., is the cross-border B2B digital trading platform for power industry. The platform has gathered nearly 80,000 electrical equipment manufacturers to provide over 170,000 cost-effective electrical equipment products with international quality selection, helping global users of power industry to achieve smart online procurement with one-stop trading service.

1. How does a power transformertransform voltage?

The transformer is made according to electromagnetic induction. It consists of an iron core stacked with silicon steel sheets (or silicon steel sheets) and two sets of coils wound on the iron core. The iron core and the coils are insulated from each other without any electrical connection.

It has been proved by the theory that the voltage ratio of the primary coil to the secondary coil of the transformer and the turns ratio of the primary coil to the secondary coil is related. There are fewer secondary coils than primary coils, which is a step-down transformer. Otherwise, it is a step-up transformer.

2. What are the components of the power transformer components?

Transformer components are mainly composed of iron core and coil, in addition to the oil tank, oil pillow, insulating sleeve, and tap opening.

3. What is the role of power transformer oil?

The functions of transformer oil are insulation and heat dissipation.

4. How is the voltage regulator adjusted?

The structure of the voltage regulator is the same as the autotransformer, and the iron core is made into a ring coil and wound on the ring core.

The secondary coil tap uses a sliding brush contact to make the contact slide in a ring along the surface of the coil to achieve a smooth voltage regulation.

5. What is the voltage change rate of the transformer?

The voltage change rate of the voltage regulator is one of the main performance indexes of the transformer. When the transformer supplies power to the load, the voltage at the load end of the transformer will inevitably drop. The ratio of the reduced voltage value to the rated voltage value is the rate of voltage change.

6. How to ensure that the transformer has a rated voltage output?

Too high or too low voltage will affect the normal operation and service life of the transformer, so the voltage must be adjusted.

The method of voltage regulation is to draw several taps in the primary coil to connect to the tap opening. The tap opening changes the number of turns of the coil by rotating the contacts. As long as the position of the tap changer is turned, the required rated voltage value can be obtained. It should be noted that voltage regulation should usually be performed after the load connected to the transformer is cut off.

As a cross-border B2B platform, ESGCC Global has many related products.

35kV Power Transformer/KEMA cetificate/LEEEC

Oil-immersed Power Transformer/Power Transfomer/Electric Transformer/500kV

If you want to know more information, you can visit https://g.esgcc.com.cn/products/AC-Transformer.html

ESGCC Global, built by State Grid Electronic Commerce Co., Ltd., is the cross-border B2B digital trading platform for power industry. The platform has gathered nearly 80,000 electrical equipment manufacturers to provide over 170,000 cost-effective electrical equipment products with international quality selection, helping global users of power industry to achieve smart online procurement with one-stop trading service.

The transformer is a functional component made by the principle of electromagnetic induction, which can transmit and change electrical energy or signal. It is mainly used to increase or decrease AC current and change impedance. Transformers are widely used. For example, they can transmit alternating current in power supply and distribution lines, electrical equipment and electronic equipment, and play the role of voltage transformation, current transformation, impedance transformation or isolation. There are many ways to classify transformers, and they can be divided into single-phase transformers and three-phase transformers according to the number of power supply phases.

The transformer is made by winding two or more sets of coils on the same coil frame or on the same iron core. Generally, the coil connected to the power source is called the primary winding, and the remaining coils are called the secondary windings.

1. Single-phase transformer structure characteristics

A single-phase transformer is a transformer whose primary winding is a single-phase winding. The primary winding and the secondary winding of the single-phase transformer are wound on the iron core, the primary winding is the AC voltage input terminal, and the secondary winding is the AC voltage output terminal.

2. Structure characteristics of the three-phase transformer

A three-phase transformer is a kind of transformer that is widely used in power equipment. The three-phase transformer is actually composed of three single-phase transformers with the same capacity. The primary winding (high-voltage coil) is three-phase, and the secondary winding (low-voltage coil) is also three-phase.

The internal structure of the three-phase transformer and the single-phase transformer are basically the same, both composed of the iron core (body) and the winding. The winding is the circuit of the transformer, the iron core is the magnetic circuit of the transformer, the two constitute the core of the transformer, namely the electromagnetic part. There are six sets of windings inside the three-phase power transmission transformer.

As a cross-border B2B platform, ESGCC Global has many related products. Here are some examples:

Oil-immersed Power Transformer/Power Transfomer/Electric Transformer/500kV

330 kV Power Transformer /Three Phase/LEEEC/KEMA cetificate

If you want to know more information, you can visit https://g.esgcc.com.cn/products/AC-Transformer.html

ESGCC Global, built by State Grid Electronic Commerce Co., Ltd., is the cross-border B2B digital trading platform for power industry. The platform has gathered nearly 80,000 electrical equipment manufacturers to provide over 170,000 cost-effective electrical equipment products with international quality selection, helping global users of power industry to achieve smart online procurement with one-stop trading service.