The power transformer is an important and widely used transformer. It is commonly used to step up and step down voltages in power generation and distribution plants, respectively.
A power transformer is a passive electrical device that transmits electrical energy from one electrical circuit to another or numerous circuits. In the core of the transformer, the fluctuating current is created in varying magnetic flux by any one coil of a transformer. This includes varying electromotive forces across any other coils located around the same core.
Electrical energy can be transported between the independent coils without the metallic connections between the two circuits. Faraday’s law, which indicated the induced voltage effect in any coil owing to changing magnetic flux encircled by the coil, was introduced in 1831. Transformers are often employed in alternating current to increase the low voltage at the high current or to decrease the high AC voltage at the low current.
Knowledge of fundamental concepts, facts and applications of power transformers is beneficial for Government exam preparation.
Why are Power Transformers used in the Electrical Power System?
A power transformer is used in electrical power networks for a variety of purposes. However, reducing power loss during electrical power transmission is one of the most important reasons for employing power transformers.
Let us look at how a power transformer reduces power loss significantly:
The power loss equation is given by:
P = I2 R
In the equation, I represents the current flowing through the conductor, and R represents the resistance of the conductor.
We can deduce from the equation that power loss is directly proportional to the square of the current flowing through the conductor. As a result, the lower the magnitude of the current flowing through the conductor, the less power is lost.
Consider the following example to better grasp the aforementioned theory:
- Assume a starting voltage of 100 V, a load current of 5 A, and a delivered power of 500 W. In this situation, the transmission line must convey a 5 A current from the source to the load. If we increase the voltage to 1000 V at the start, the transmission lines only need to carry 0.5 A to transmit the same power of 500 watts.
- A power transformer steps up the voltage at the transmission line’s beginning, and another power transformer steps down the voltage at the transmission line’s end.
- This configuration allows for a significant reduction in the magnitude of the current to be travelled over a distance of 100+ kilometres.
Construction of Power Transformers
The design, types, and accessories of a power transformer are determined by its size, application, and location. The following are the basic components required for power transformer construction:
- Steel Tank (Body)
- Coil Winding
- Vent Pipe
- Buchholz Relay
- Tap Changing Switch
Applications of Power Transformer
Transformers are capable of switching with ease from one voltage to another, from higher to lower as well as from lower to higher. These transformers come in a variety of shapes and can be used in a wide range of electronic devices and circuits.
The distribution and transmission of electrical power are two uses for power transformers. These transformers are also used extensively in power plants. Power transformers are also employed by traditional electric utilities and industrial facilities. Power transformers are used in high-voltage transmission networks to step up and step down voltage.
These transformers are utilised for the transmission of high loads. These large transformers, which are employed in transmission and production, are compared to distribution transformers in terms of size. Transformers are used as setup tools for transmission so that the loss can be decreased to a specific amount of power flow. These transformers will operate close to the keen point B-H curve and are built to make the best use of the core components.