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Category: Transformer

A transformer is a static electrical device that transfers electrical energy between two or more circuits. A varying current in one coil of the transformer produces a varying magnetic flux, which, in turn,
a varying electromotive force across a second coil wound around the same core. Electrical energy can be transferred between the two coils, without a metallic connection between the two circuits. Faraday’s law of
induction discovered in 1831 described the induced voltage effect in any coil due to changing magnetic flux
encircled by the coil.

Transformers are used for increasing or decreasing the alternating voltages in electric power applications, and for coupling the stages of signal processing circuits.

Since the invention of the first constant-potential transformer in 1885, transformers have become essential for the transmission, distribution, and utilization of alternating current electric power. A wide range of
transformer designs is encountered in electronic and electric power applications. Transformers range in size from RF transformers less than a cubic centimeter in volume, to units weighing hundreds of tons used to
interconnect the power grid.

Parallel Operation of 1 & 2 Phase Transformers

Parallel Operation of 1 & 2 Phase Transformers

By parallel operation we mean two or more transformers are connected to the same supply bus bars on the primary side and to a common bus bar/load on the secondary side. Such requirement is frequently encountered in practice. The reasons that necessitate parallel operation are as follows. Non-availability of a single large transformer to meet the total load. The power demand might have increased over a time necessitating augmentation of the More transformers connected in parallel will then be pressed…

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Phasor Diagrams & Testing Transformer

Phasor Diagrams & Testing Transformer

  The  resulting equivalent  circuit is known  as the exact equivalent circuit. This circuit can be used for the analysis of the behavior of the transformers. As the no-load current is less than 1% of the load current a simplified circuit known as ‘approximate’ equivalent circuit is usually used, which may be further simplified to the one. On similar lines to the ideal transformer the phasor diagram of operation can be drawn for a practical transformer also. The positions of the…

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Three Phase Transformer

Three Phase Transformer

It is the three phase system which has been adopted world over to generate, transmit and distribute electrical power. Therefore to change the level of voltages in the system three phase transformers should be used. Three number of identical single phase transformers can be suitably connected for use in a three phase system and such a three phase transformer is called a bank of three phase transformer. Alternatively, a three phase transformer can be constructed as a single unit. Introducing…

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Poly Phase Connections and Transformers

Poly Phase Connections and Transformers

The individual transformers are connected in a variety of ways in a power system. Due to the advantages of polyphase power during generation, transmission and utilization polyphase power handling is very important. As an engineering application is driven by techno-economic considerations, no single connection or setup is satisfactory for all appli- cations. Thus transformers are deployed in many forms and connections. Star and mesh connections are very commonly used. Apart from these, vee or open delta connections, zig zag connections…

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Ideal Transformer

Ideal Transformer

Introduction:- Transformers are one of the most important components of any power system. It basically changes the level of voltages from one value to the other at constant frequency. Being a static machine the efficiency of a transformer could be as high as 99%. Big generating stations are located at hundreds or more km away from the load center (where the power will be actually consumed). Long transmission lines carry the power to the load Centre from the generating stations….

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Auto -Transformer

Auto -Transformer

Introduction:- So far we have considered a 2-winding transformer as a means for changing the level of a given voltage to a desired voltage level. It may be recalled that a 2-winding transformer has two separate magnetically coupled coils with no electrical connection between them. In this lesson we shall show that change of level of voltage can also be done quite effectively by using a single coil only. The idea is rather simple to understand. Suppose you have a…

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