A transformer is an electrical device that is utilized to conduct power from one circuit to another by electromagnetic induction. The power transfer is conducted without frequency change. In an electronic approach, the term power transformer is employed to offer numerous AC supplies of different voltages and relevant values of current from the public electricity supply. Also, it is used to indicate transformers with a 500KVA rating or more generous.
The Power transformer is a type of transformer used to conduct or transfer electrical energy in all the electrical or electronic circuit parts between the generator and the primary distribution circuits. These transformers are practiced in distribution techniques to interface step up and step down voltages.
These transformers are practiced in distribution techniques to interface step up and step down voltages. The usual and most common type of power transformer is liquid absorbed, and the life span of these transformers is approximately around 30 years. Power transformers can be categorized into three types depending on the scales or different ranges. That includes small power transformers, medium power transformers, and large power transformers.
- The small power transformers range from 500-7500kVA
- The medium power transformers range from 100MVA
- The immense power transformers range from 100MVA and beyond.
These transformers conduct or transform the voltage. It operates a low voltage and a high-current circuit at one side of the transformer while, on another side of the transformer, it serves a high voltage and low-current circuit.
Power Transformer Layout/Design:
The skeleton or the structure of the power transformed is planned, sketched, or designed with metal overlaid by sheets. It is fastened into either a core type or shell type. The transformer’s structure or sketch is entwined and linked utilizing conductors to form three 1-phase or one 3-phase transformer.
Three 1-phase transformers need each bank separated from the additional and, therefore, provide a chain of service when one bank fails.
A single 3-phase transformer, perhaps the shell or core type, may not run or function even with one bank out of service. The 3-phase transformer is not much costly to construct and design. Also, it has a smaller step and runs or functions relatively with higher efficiency.
The structure of the transformer is absorbed in a fire retardant protecting oil within a tank. The conservatory on the cover of the oil tank allows the increasing oil to fall in it. The tank’s bushings allow conductors to accurately enter and exit the tank without inciting the outer shell. The power transformer can be functioned surpassing its small rating as long as it tarries within the 65ºC increase of the temperature. To enable the above nominal approach, transformers are designed or built-in to include fans that cool the transformer’s essence to a point beneath the denoted temperatures.
Types Of Power Transformers And Their Applications:
A power transformer is a static, stable machine adopted and utilized for transforming power from one circuit to another without altering the frequency. Power Transformers Manufacturers are practiced between the generator and distribution circuits, where there is a transition or change between voltage levels. The complete power mode constitutes many generation locations, distribution points, and interconnections within the system or neighboring operations. A transformer assists in minimizing the loss of power also at very high voltages due to its resistance. It transmits the received power to an accurate range to ensure that the power is employed according to the requirement. There are many distinct types of transformers, and every type is utilized for a varied purpose. We have laid down a list of some of the most widely practiced transformers and their usage or applications:
They are smaller, cheaper, and more volatile than standard dual-winding transformers. Autotransformers do not render electrical isolation.
These transformers have a portion of their winding inserted in both input and output circuits – voltage is used across a part of the winding. A higher or lower voltage is produced across different parts of the same winding. Therefore, these transformers can transfer up or down between voltages in the ranges from 110-117-120 and 220-230-240 volts. The comparable power rating of an autotransformer is lower than the exact actual load. Also, the application of substantial three-phase autotransformers is made in electric power distribution systems.
- Polyphase Transformers:
Power distribution systems need three-phase transformers to be able to step up or down voltages. Notwithstanding, single-phase transformers can be put together to modify and conduct power between two three-phase systems also. However, three-phase transformers are made or produced particularly for such uses that require lesser material and are less in weight and size than their modular equivalents. These transformers are manufactured of three sets of primary and secondary windings. In this case, all three primary windings are connected mutually, and all the three secondary windings are also attached. The primary purpose or function of a polyphase transformer is that they are utilized for grounding and suppression of symphonious currents.
- Leakage transformers
Leakage transformers are also most commonly known as stray-field transformers. They have a majorly higher leakage inductance compared to all the other types of transformers, which can be enhanced by a magnetic bypass or shunt in essence between primary and secondary windings. It can also be modified or changed with a set screw. Due to the loose, insecure coupling within the windings, these transformers have a current restriction. The input and output currents of leakage transformers are relatively low enough to obstruct thermal overload in any circumstances.
- Resonant transformers:
Resonant transformers have one winding with a capacitor that appears or performs as a tank/tuned circuit. They are operated by pulse or square wave and can function or run as high Q-factor bandpass filters. These transformers use the leakage inductance of the secondary winding connected with external capacitors to create one or more resonant circuits. They are popularly utilized in radio circuits and switching power supplies.