What is a Power Transformer? Explain its Types

What is a transformer

Electric power transmission or AC power transmission is done with the help of the transformer. It can transfer electric power from one circuit to another without changing frequency. It can raise or lower the voltages with a corresponding increase or decrease in current. Transformer works by faraday’s law of electromagnetic induction. A transformer consists of two conducting coils having mutual inductance, one of the coils is primary winding which receives electric power from the supply and the electric power to the load is delivered by the secondary winding.

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What is a power transformer

Power transformers are mostly used in electric power transmission and distribution systems. The power rating of these transformers can be known by the cooling method of the transformer. Ampere rating is increased in a distribution transformer by increasing the size of primary and secondary windings. The voltage level can be increased by increasing the voltage of the insulation. A power transformer is devices that are used to convert inbound electricity or voltage to a higher or lower value in order to accommodate the current flow needed for special purposes.

Transformer testing

Types of transformers and their applications

What is the need for power transformer and what are its functions

Power transformers are inevitable in power grids, it plays a great role in the transfer of power and it transfers the power without overloading the circuitry. So the power transformer can also be considered as the safety feature because it can reduce some of the risks that are associated with utilizing the electrical current. The functions of power transformers are to transfer the power from the source to the destination and regulate the voltage. This process is done by the coil system of the device, the coils function as conductors, which helps to maintain the current flow within the required range. Voltage control is possible by managing the magnetic field fluctuation that takes place within the core of the power transformer.

What are the components and fittings of a power transformer

The components of the power transformers are iron core, the windings, tap changing gear, and protection equipment for the transformer. The iron core provides the magnetic circuit, windings the tank containing transformer and oil, tap changing gear, and other fitting associated with the operation and protection equipment for the transformer.

What are the types of power transformers

The two major types of power transformers are laminated core and toroidal. Laminated cores are those commonly shaped cube transformers that are used in power adaptors and they are stronger and cheaper than toroidal. This is the most widely used transformer in appliances to convert mains voltage to low voltage to power electronics. The toroidal types are smaller and lighter, for the same power rating. They produce less electrical noise and are more efficient. Voltage can be doubled by joining the secondary winding in series, it can be joined in parallel to get higher current.

Step-up transformer

The step-up transformer creates a low voltage in the primary to create higher voltage in the secondary and this can be achieved by a greater number of windings in the secondary coil. An example of such a need is a cathode ray tube that runs of 110V wall socket but needs thousands of volts to operate. In general, it can be described as to convert low voltage high current to high voltage low current.

Step-down transformer

In this type, the reverse process takes place that is, it is designed to convert high voltage low current to low voltage high current. Reversing the winding ratio of the step-up transformer produces a step-down transformer. An example of this would be a radio that runs off 12V of batteries, but also runs off a wall outlet using an adaptor with a step-down transformer inside.

Current transformer

A current transformer is a type of transformer that provides a flow of current in the secondary circuit that is properly perpendicular to the amount of current flowing in its primary circuit. The transformers core fits around the large line, which itself acts as a single winding primary circuit. The secondary winding count is high as in normal transformer. The secondary circuit includes the ammeter.

Isolation transformer

Isolation transformer doesn’t increase or decrease the voltage though they can. They are used to do other purposes such as breaking a circuit into primary and secondary, so the direct current noise can be avoided and they can prevent high-frequency noise from capacitance buildup, it can also prevent unintentional ground connections between the primary and secondary.

Traction transformer

Traction transformers are installed in electric cars, electric locomotives, and electric multiple units. Its main purpose is to transform the overhead contact line voltage to suitable voltage for traction converters.

What is a Power Transformer in a Substation?

The transformer is the center of the substation. The transformer modifies the relationship between the input voltage and current and the exiting voltage and current. Substation transformers are rated based on their primary & secondary voltage connections, as well as their power carrying capacity.