The difference between current transformers
Jul 31, 2023| 1. Formal differences
In terms of form, current transformers are mainly divided into two categories: plug-in current transformers and iron core current transformers.
Plug-in current transformers, as the name suggests, can be inserted into cables, wires, etc. in the power system, so that the current transformer can directly sense the current in the system. This current transformer is easy to install and is suitable for situations where it is inconvenient to start work on site. The iron core current transformer needs to pass the tested cable or wire through the inner iron core of the transformer to induce current. It is suitable for more accurate current measurement and protection, because the iron core current transformer is less disturbed by the outside world and has good stability.
2. The difference in working principle
From the perspective of working principle, current transformers can also be divided into two categories: magnetostrictive current transformers and electromagnetic current transformers.
The magnetostrictive current transformer works based on the magnetostrictive effect. Its working principle is to use the force of the magnetic field to push an iron core to deform in the axial direction, so as to achieve the purpose of current mutual induction. This kind of current transformer is small in size, light in weight, and has good lightning protection performance, but its accuracy is not high, and it is rarely used in large current measurement and protection.
Electromagnetic current transformers are mainly divided into basic type and transformation ratio type. Its working principle is to use the magnetic field generated by the current in the coil to induce the potential in the iron core, and then amplify the potential and output it. The precision of the electromagnetic current transformer is higher than that of the magnetostrictive current transformer, and it is suitable for occasions that require precise measurement and protection.
3. The difference in the scope of application
Current transformers can also be classified according to different application ranges, such as circuit breakers and power distribution cabinets with different rated currents, which are widely used in power systems.
Among them, the backup current transformer is mainly used for the protection and control of equipment such as circuit breakers or contactors, while the measuring current transformer is mainly used in electric energy metering and monitoring systems, which require high accuracy and stability.
In the power system, different types of current transformers have their own application advantages, but also have certain limitations. Therefore, when selecting a current transformer, various factors need to be considered comprehensively according to the actual situation to achieve the best application. Effect.