Como funciona um Transformador?

Summary

This video explains the basic operation and construction of a three-phase transformer, emphasizing electromagnetic induction principles. It covers how transformers adjust voltage levels for more efficient energy transmission, highlighting the role of fluctuating magnetic fields and coil design. The script explains the difference between primary and secondary windings, and the use of ferromagnetic cores. It also touches on transformer configurations, including Delta and Star connections for different voltage levels, and how energy losses are managed through oil cooling systems. The video offers insight into the components and working principles that enable power transmission over long distances.

Takeaways

• 😀 Transformers help in transferring energy at different voltages, improving transmission efficiency over long distances.
• 😀 The basic working principle of a transformer is electromagnetic induction, where a fluctuating magnetic field induces an electromotive force in a coil.
• 😀 The magnetic field produced by an alternating current in a conductor surrounds it, and this fluctuating field can be linked to a secondary winding.
• 😀 The fluctuating magnetic flux induces an electromotive force (emf) in the secondary coils, which is related to the primary coil's input voltage.
• 😀 The voltage in the secondary coil can be increased or decreased based on the number of turns in the primary and secondary coils.
• 😀 In a transformer, the induced electromotive force (emf) is the sum of the individual emf values from each winding coil.
• 😀 Transformers use either a star or delta configuration for their windings, with star being used for high voltage and delta for low voltage.
• 😀 A three-phase transformer uses three monophase transformers, and the windings are concentric with one another.
• 😀 High-power transformers use a special type of winding known as the disk winding, where low-voltage windings are connected in a delta configuration and high-voltage ones in a star configuration.
• 😀 The core of a transformer is made up of thin, insulated steel laminations, which help reduce energy loss caused by eddy currents.
• 😀 Transformers are often immersed in oil to dissipate heat generated due to energy losses during the transfer of power, with the oil acting as a coolant.

Q & A

What is the basic principle behind the operation of a transformer?

The basic principle behind the operation of a transformer is electromagnetic induction, where a changing magnetic flux through a coil induces an electromotive force (EMF) in the coil.

How do transformers help in improving the efficiency of power transmission?

Transformers help improve the efficiency of power transmission by allowing energy to be transferred over long distances at a different voltage, which reduces energy loss.

What is the role of a ferromagnetic core in a transformer?

The ferromagnetic core in a transformer helps to effectively channel the fluctuating magnetic field generated by the primary winding to the secondary winding, facilitating the induction of EMF.

What is the relationship between the number of turns in the primary and secondary windings and the voltage?

The voltage in the secondary coil is directly related to the ratio of the number of turns in the secondary to the primary coil. A higher number of turns in the secondary increases the voltage, while fewer turns decreases it.

How is the induced EMF in the secondary coil calculated?

The induced EMF in the secondary coil is calculated based on the number of turns in the secondary coil and the primary voltage, as the magnetic flux linking both windings is the same.

What is the key difference between a single-phase and a three-phase transformer?

A three-phase transformer uses three single-phase transformers arranged in a slightly different configuration, typically with primary and secondary windings connected in star or delta configurations.

What is the advantage of using a three-phase transformer over a single-phase transformer?

A three-phase transformer allows for higher power transmission and is more efficient for industrial and large-scale applications, as it provides a constant power flow, unlike single-phase systems which can have power fluctuations.

What type of winding configuration is used in high-power transformers?

High-power transformers typically use disk windings, where the individual disk windings are connected in series through internal and external crossovers.

Why is transformer oil used in transformers?

Transformer oil is used for cooling purposes. It dissipates the heat generated during the energy transfer from the primary to the secondary coil by natural convection, helping to prevent overheating.

What happens to the transformer oil as it absorbs heat?

As the transformer oil absorbs heat, it expands. A conservator tank is used to accommodate the change in volume and maintain a stable operation.