What is current transformer? Where do we use current transformers?
Current transformers are measurement transformers used to measure the current passing through the circuit.
31 January, 12:01
Current transformers are measurement transformers used to measure the current passing through the circuit. Direct measurement of high currents by measuring instruments is not only costly, but also sometimes very dangerous and difficult.
As it is known, electric current is the movement of electrically charged particles from one point to another. Electrical energy is carried by electrons moving inside conductive cables. Measuring the current during the electricity transfer is of great importance and the current transformer comes into play at this point.
What is Current Transformer?
Current transformers are measurement transformers used to measure the current passing through the circuit. Direct measurement of high currents by measuring instruments is not only costly, but also sometimes very dangerous and difficult. Therefore, the current passing through the circuit must be reduced to a certain value in order to be measured. The current transformer connected in series to the circuit reduces the magnetic field created by the current passing through the primary circuit and transfers it to the second circuit called the secondary. Thanks to the cyclic current occurring in the secondary circuit, the amount of current flowing in the primary circuit can be measured by the measuring device connected in parallel to the secondary winding.
Structure of Current Transformers
Current transformers basically consist of three parts: a magnetic iron core, a primary winding wound on this core, and a secondary winding wound on this primary winding in the opposite direction. The current passing through the primary winding creates a magnetic flux on the magnetic iron core. This magnetic flux in the core causes a voltage to be induced on the secondary winding. The measuring device connected in parallel to the secondary winding creates a magnetic flux in the magnetic iron core in the opposite direction because the current passing through the secondary circuit is opposite to the winding direction. This magnetic flux balances the magnetic flux created by the current passing through the primary winding. For this reason, the secondary ends of the current transformers must be short-circuited by a measuring device or a load. Otherwise, a magnetic flux in the opposite direction will not occur and since the flux is not balanced, the magnetic iron core may heat up and fail. In addition, this situation poses a danger to users as it will increase the voltage at the secondary ends.
Current Transformer Usage Areas and Types
Current transformers are divided into different types according to the voltage, cooling and construction used in them. These are as follows:
- Low Voltage Current Transformers
- High Voltage Current Transformers
- Dry Type Current Transformers
- Oily Type Current Transformers
- Wound Current Transformers
- It can be classified as Busbar Type Current Transformers.
Current transformers are basically used for measurement purposes. If a current transformer is not used, large-sized measuring devices must be used and larger-sized protection relays must be manufactured to measure high current values. This is both a costly and extremely dangerous choice. The use of current transformers allows to utilize the smaller measuring devices and protection relays. While this offers a much more economical solution, it also enables safe operation. Because measuring devices and protection relays connected to the secondary end are isolated from the primary voltage.
- • Thanks to its wide product range, ENTES Current Transformers offer solutions for the special needs of infrastructure, buildings and industry wherever energy is used.
- • ENTES Medium Voltage Compatible Current Transformers
- • ENTES Low Voltage Current Transformers
- • ENTES Split Core Current Transformers
- • ENTES Clamp Type Current Transformers
- • ENTES Compact Split Core Current Transformers
- • ENTES Three Phase Current Transformers
Whether for compensation or measurement purposes, the selection of the current transformer is one of the most important issues when designing a new system. Although not given much importance, current transformers are very important for businesses. Incorrect product selection can cause inaccurate measurements and affect the entire system.
When current transformers are considered, it is observed that their basic structures include primary winding, secondary winding, magnetic core and insulation material. This content may be different in some types. It is also possible to add additional apparatus and in this way, different types can be created. The main point to be considered here is the selection of the current transformer.
Pay Attention to These Points For Current Transformer Selection!
The main point to be considered during the selection of the current transformer is the type of the product. For example, medium voltage compatible current transformers are generally used at medium voltage values. At the same time, these products are used with reactive power control relays.
Another product is low voltage current transformers. The mentioned products are connected in series to the circuit. These two types are preferred by many businesses due to the advantages they offer.
Another product type is split core current transformers. Split core current transformers are generally preferred because they are easy to install. If there are assembly problems in the working environment and the product needs to be re-installed after removal, this product type can be selected.
In cases where assembly is desired without turning off the power in the panels, clamp type, split core current transformers can be preferred.
Selection of the Correct Current Transformer must be Made to Obtain the Best Quality Product!
During the selection of the current transformer, the additional advantage offered by each product should be considered in detail. All products generally work on the same principle. But some are suitable for medium voltage. Others offer high accuracy for low voltage.
For this reason, it is necessary to pay attention to the type of product and the advantages offered by the products. Another important point is of course product quality. Quality products will offer a long service life. In this sense, our company will meet your needs in the best way thanks to its high quality products and wide product range.
Writter: Guest Writer