Working of Current Transformer
The operation of a current transformer follows the same basic principle as that of a conventional transformer. The primary current is drawn from the primary winding, and through electromagnetic induction, it undergoes a step-down transformation. The resulting output is then obtained from the secondary winding.
Equivalent circuit of current transformer
The following is the Equivalent circuit of the Current transformer
The Equivalent circuit of the CT is similar to the power Transformer and Induction Motor.
In the given circuit and are the primary side resistance and the reactance.So the impedance of the primary side can be written as Similarly the secondary side has and as the resistance and the reactance so the impedance is and impedance across load can be written as . is the core loss current and is magnetizing Current.The active component for heat loss is written as the resistance , and the reactive component, where energy is stored as electromagnetic energy, is written as the magnetizing reactance .
CT parameters are
= Flux in the core of transformer
= phase angle in transformer
n=turns ratio
=Primary side voltage
= Secondary side voltage
= primary side current
= Secondary side current
= Primary side resistance
= primary side reactance
= Secondary side resistance
= Secondary side reactance
= Load side resistance
= Load side reactance
= magnetizing Current
= core loss current
= active component
= magnetizing reactance
In CT the primary current is independent of load
Ideal condition of CT
Let us assumed that load is connected so the impedance is . rp should nearly equals to zero (as primary side mainly has one or two turns) and and xs should be very less. and load should be mainly resistive.
Current Transformers
In this article, we will discuss what is A current Transformer?, Construction of the Current Transformer, Its Working, Phasor Diagram, Errors in the current Transformer, and Its Types, and At last we will conclude this article With its advantages, disadvantages, Application, and FAQs.
Table of Content
- What is a Current Transformer?
- Construction of the Current Transformer
- Working of Current Transformer
- Phasor Diagram of Current Transformer
- Current Transformer Errors
- Reduction of Errors in Current Transformer
- Types of Current Transformers