Significance of transformersTransformers in electric transmissionElectric Transmission.

The discovery of electricity has been one of the major breakthroughs in the history of mankind. After its discovery, life has become much faster and easier than one could have ever imagined. With a single click, one can turn on the fan/AC, or get a glass of cold water from the refrigerator to provide welcome relief when it gets hot. When we are hungry, we can cook food in the microwave oven in under a minute. Boredom can be reduced  instantly by turning on the television for some interesting entertainment. It is well known that whatever we use in our daily life to give  comfort, like the refrigerator, television, AC, geyser, music system, computers and so on, all use a certain amount of electricity.  Many household devices such as televisions and music systems need high voltage , while others such as doorbells need comparatively lower voltage. To regulate this voltage, we need to use electrical transformers.

What are transformers?

An electrical transformer is a static machine that is used for transforming power from one circuit to another, without changing the frequency and  altering voltage. In other words, a transformer basically transfers electricity generated in the power plants, to our homes and other places that require it. A simple transformer is made from two coils of insulated wires. These wires are wound around an iron-containing structure called the core. One coil,  is called the primary,. It is connected to a source of alternating current that produces a constantly varying magnetic field around the coil. The varying magnetic field, in turn, produces an alternating current in the other coil. This coil, is called the secondary, and is connected to a separate electric circuit.

Why are transformers used?

At power plants, electrical  power is generated at low voltage  levels as it is very cost effective. However, during transmission, the voltage is increased. This is because increased voltage levels can cause reduction of ohmic losses, and improvement of voltage regulation. This change is brought about by a stepup transformer at the sending site. As this high voltage power cannot be distributed to  consumers directly, it must be reduced to the desired level at the receiving end with the help of a step down transformer. This is the general use of an electric transformer in power supply.

At the household level, the use of a step-down transformer is 220 volts. As we have already seen, step up and step down transformers are used to increase and decrease the voltage respectively. A third type of transformer is the three phase transformer. It is  used worldwide to transfer power. This is a common method of ac-power generation, transmission and distribution. It is mainly used to supply power to large motors and heavy loads. Moreover, the use of three phase systems is considered to be more economical than using single-phase and two-phase systems.

The Process

At present a large number of companies are involved in the process of transformer manufacture. The process involves:

  • Winding: Copper or aluminum wiring is wound around the core as primary and secondary coils.
  • Sheets: The core is made of cold rolled-grain oriented laminations’ in the form of sheets.
  • Assembling: This is the final stage. During this stage the wound coils are put inside the assembled core. Insulation is provided wherever necessary. The primary coil and the secondary coil are respectively connected to the AC supply and the electric circuit. This assembly is protected from  attacks due to moisture, by keeping it in a hot air chamber, where a high temperature is continuously maintained.


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