Classifcation of Transformershttp://www.elprocus.com/Classifcation of TransformersIntroductionA transformer is a static device. The word transformer comes form the word transform. Transformer is not an energy conversion device, but it is device that changes AC electrical power at one voltage level into AC electrical power at another voltage level through the action of magnetic eld. !t can be either to step"up or step down.http://www.elprocus.com/Classifcation of TransformersWorking Of TransformerThe main principle of operation of a transformer is mutual inductance between two circuits which is lin#ed by a common magnetic $u%. A basic transformer consists of two coils that are electrically separate and inductive, but are magnetically lin#ed through a path of reluctance. http://www.elprocus.com/Classifcation of TransformersWorking Principal The changing current in the primary coil, is usually achieved by applying an alternating voltage, resulting in an alternating current &AC' AC input. As the alternating current changes magnitude and direction, a magnetic eld is produced, which changes in a corresponding manner C"C()* +roup of *ngineers.The eld from the primary coil is intensied and concentrated through the secondary coil by an iron core AC output. The changing $u% through the secondary coil, induces a potential di,erence across the secondary coil.http://www.elprocus.com/Classifcation of TransformersClassifcation of TransformerAs per phase -ingle phase Three phase As per coreCore type -hell typeAs per cooling system-elf"cooled Air cooled .il cooledhttp://www.elprocus.com/Classifcation of TransformersSingle Phase Transformer (As per Phase) Asingle"phase transformercan operate to either increase or decrease the voltage applied to the primary winding.Two or more winding, coupled by a common magnetic core. !t is called a -tep uptransformer. http://www.elprocus.com/Classifcation of TransformersThree Phase Transformer (As per Phase) A single enclosure with three primary and three secondary windings wound on a common core is all that is re0uired.-ince each single"phase transformer has a primary and a secondary winding, then 1 single"phase transformers will have the re0uired 1 primary and 1 secondary windings.http://www.elprocus.com/Classifcation of TransformersIdeal Transformer An ideal transformer is a transformer which has no loses, i.e. its winding has no ohmic resistance, no magnetic lea#age, and therefore no !23 and core loses. !deal transformer will be used in characteri4ed the practical transformer.http://www.elprocus.com/Classifcation of TransformersCore Type Transformer (As per core)The windings are given to a considerable part of the core. The coils used for this transformer are form"wound and are of cylindrical type. The general arrangement of the core"type transformer with respect to the core.http://www.elprocus.com/Classifcation of TransformersShellType Transformer (As per core)!n shell"type transformers the core surrounds a considerable portion of the windings. The coils are form"wound but are multi layer disc type usually wound in the form of panca#es. The whole winding consists of discs stac#ed with insulation spaces between the coils. http://www.elprocus.com/Classifcation of TransformersOil !illed SelfCooled Type (As Per Cooling System).il lled self cooled type uses small and medium"si4ed distribution transformers. The assembled windings and core of such transformers are mounted in a welded, oil"tight steel tan#s provided with a steel cover. The oil helps in transferring the heat from the core and the windings to the case from where it is radiated out to the surroundings.http://www.elprocus.com/Classifcation of TransformersOil !illed Water Cooled Type (As Per Cooling System)This type is used for much more economic construction of large transformers.The method is used here as well" the windings and the core are immersed in the oil. The only di,erence is that a cooling coil is mounted near the surface of the oil, through which cold water #eeps circulating. This water carries the heat from the device. This design is usually implemented on transformers that are used in high voltage transmission lines. http://www.elprocus.com/Classifcation of TransformersAir "last Type (As Per Cooling System)This type is used for transformers that use voltages below 25,666 volts.The transformer is housed in a thin sheet metal bo% open at both ends through which air is blown from the bottom to the top.http://www.elprocus.com/Classifcation of TransformersAd#antagesCopper re0uired is very less.7igh e8cient than two winding transformer .-mall si4e and low cost.3esistance and lea#age reactance is less compared to two winding transformer.Copper losses are less.-uperior voltages regulation than two winding transformer.http://www.elprocus.com/Classifcation of Transformers$isad#antages9ow impedance hence high short circuit currents for short circuits on secondary side.!f a section of winding common to primary and secondary is opened , full primary voltage appears across the secondary resulting in higher voltage on secondary and danger of accidents.:o electrical separation between primary and secondary which is ris#y in case of high voltage levels .http://www.elprocus.com/Classifcation of TransformersConclusion*lectrical transformer is a static electrical machine which transforms electrical power from one circuit to another circuit, without changing the fre0uency.Transformer can increase or decrease the voltage with corresponding decrease or increase in current.They are available in power ratings ranging from m; to