Current transformer theory pdf

Enter the email address you signed up with and we'll email you a reset link. Need an account? Click here to sign up. Download Free PDF. Devesh Jayaswal. A short summary of this paper. In Very Simple words. Transformer is a device which: 1. Transfer Electrical power from one electrical circuit to another Electrical circuit. Work through on electric induction. When, both circuits take effect of mutual induction. Just imagine that there are no transformers. How many power plants do you think have to be set up in order to power up a city?

It is expensive. Numerous power plant have to be set up in order to have sufficient power. Transformers help by amplifying the Transformer output stepping up or down the level of voltage or current. When the number of turns of the secondary coil is greater than that of primary coil, such a transformer is known as step up transformer. Likewise when the number of turns of coil of primary coil is greater than that of secondary transformer, such a transformer is known as step down transformer.

Single Phase Transformer 2. Three Phase Transformer Below are the more types of transformer derived via different functions and operation etc. Types of Transformers w. When current in the primary coil is changed the flux linked to the secondary coil also changes.

The transformer is based on two principles: first, that an electric current can produce a magnetic field electromagnetism , and, second that a changing magnetic field within a coil of wire induces a voltage across the ends of the coil electromagnetic induction. Changing the current in the primary coil changes the magnetic flux that is developed. The changing magnetic flux induces a voltage in the secondary coil. A simple transformer has a soft iron or silicon steel core and windings placed on it iron core.

Both the core and the windings are insulated from each other. The winding connected to the main supply is called the primary and the winding connected to the load circuit is called the secondary. Winding coil connected to higher voltage is known as high voltage winding while the winding connected to low voltage is known as low voltage winding.

In case of a step up transformer, the primary coil winding is the low voltage winding, the number of turns of the windings of the secondary is more than that of the primary. Vice versa for step down transformer. Core is the medium for passing the magnetic flux from primary winding to secondary winding. Generally iron core is used because it has higher permeability for magnetic flux. It means heat transfers better in iron then in wood and same as magnetic flux transfers or passes better in iron core then the air.

Time-varying mutual flux links the both primary and secondary winding in transformer. It is required that most of the flux is to be confined to a definite, high-permeability path linking the windings. Now with air ore it is not possible but with core of iron or other ferromagnetic material coupling is effectively done.

Because most of the flux in iron core is confined to a definite, high-permeability path linking the windings. As the iron core is also under the flux variation in transformer there is some voltage induced in the iron core. This voltage is called the eddy voltage and in result there is a current named eddy current flow in the iron core. These results in heating up the core.

With a solid iron core the eddy current is high. To avoid this solid iron core is not used. Thin iron core is laminated to make it non-conductive. Then this thin laminated core is stacked by several to get the complete iron core structure. With this modification eddy current is reduced but magnetic property of the iron core is remained unchanged.

Complete basics and theory of Electrical Transformer. This site uses Akismet to reduce spam. Learn how your comment data is processed. Pin Share 5. CONTENTS Basics of electrical transformer What is electrical transformer List of international standard for transformer Use of electrical transformer Types of Electrical transformer Electrical Transformer theory and concepts [1] How transformer works [2] How Energy is transferred from primary winding to secondary winding in transformer [3] Transformer formula [4] How the voltage and current is changed between the primary and secondary Transformer construction Basic construction of transformer Why there is iron core instead of air core in transformer Iron core in transformer Materials of iron core of transformer- Related Posts: Share this:.

An alternating voltage is connected to the primary coil. These create flux in the coil. As the voltage is alternating or time varying so is the produced flux. These time-varying flux produces induced voltage in the secondary winding when it cuts through the secondary coil or winding.

The main important factor is to maintaining controlled difference between the number of primary turn and secondary turn. The most important factor of transformer is its difference between the number of turns in primary and secondary.

This difference defines the transformer functional rating. Transformer construction Basic construction of transformer A basic transformer has simplest construction with primary winding set, secondary winding set and core. To reduce the losses caused by eddy currents in the core, the magnetic circuit usually consists of a stack of thin lamination. Tags: Transformer. Enter your Comment Cancel reply.