How does a current transformer work?

News | company news | Mar 22,2024

How does a current transformer work?

The size of the current in power generation, transformation, transmission, distribution and power consumption lines varies greatly, ranging from a few amperes to tens of thousands of amperes. In order to facilitate measurement, protection and control, it needs to be convert into a relatively uniform current. In addition, the voltage on the line is generally relatively high, so direct measurement is very dangerous. Current transformers play the role of current conversion and electrical isolation.

Micro current transformers are also call “instrument current transformers”. (“Instrument current transformer” has a meaning that is a multi-current ratio precision current transformer use in the laboratory, generally used to expand the instrument range.)

Current transformers are similar to transformers and work based on the principle of electromagnetic induction. Transformers convert voltage while current transformers only convert current. The winding of the current transformer connect to the measure current (the number of turns is N1) is call the primary winding (or primary winding, primary winding); the winding connect to the measuring instrument (the number of turns is N2) is call the secondary winding (or secondary winding). winding, secondary winding).

The function of the current transformer (CT for short) is to convert a larger primary current into a smaller secondary current through a certain transformation ratio, which is use for protection, measurement and other purposes. For example, a current transformer with a transformation ratio of 400/5 can convert an actual current of 400A into a current of 5A.

How does a current transformer work?-heyi