A transformer is a machine that is used for stepping down or stepping up the voltage. The output voltage is increased when a step-up transformer is used. The output voltage is decreased when using a step-down transformer. The output current will get reduced by a step-up transformer, and a step-down transformer will decrease the output current. The transformer is a device that is used to control voltages. Transformers are highly used in the distribution of alternating current power. In the year 1831, the idea of a transformer was first discussed by Michael Faraday. The transformer works on the conception of electromagnetic induction.
When a magnetic flux gets cut by a coil of wire, and the coil is a part of the circuit, then an EMF is induced, and current flows through the circuit. This current is called induced current, and the process of creating electricity using magnetism is called electromagnetic induction.
The induced electromotive force (EMF) equals the rate of change in flux.
Types of transformers
Transformers are used in many places for a variety of purposes. It is used in the power generation grid, transmission, electric energy consumption, and distribution sectors. Transformers are basically classified on the following characteristics:
- The medium used in the core
- Winding arrangement
- Installation location
- Working voltage range
Transformer related to voltage levels.
Step-up transformer – this transformer is used between the power grid and the power generator. The input voltage is lower than the output voltage.
Step-down transformer – this type of transformer is used to convert the high input voltage to the low input voltage.
Medium of the core used.
Air core transformer – the flux linkage between the coils through a medium of air. The coil is placed in a non-magnetic strip.
Iron core transformer – coils are coiled on multiple plates of iron stacked together, providing a perfect path of linkage to generate flux.
Autotransformer – there is only one winding on the core, which is laminated. The same coil is shared between the primary and secondary.
Power transformers are suitable for a high voltage application, and therefore they are used in power stations.
Distribution transformers – it is used for domestic purposes are used in distribution lanes. These are specially designed for low voltage. It has low magnetic losses and is quite easy to set up.
Measurement transformers – these are used for measuring the current, voltage, and power.
Protection transformers – these are designed to protect components in a circuit that voltage fluctuations can damage.
How do transformers work? or Function of transformers
The transformers follow the faradays law of electromagnetic induction. There are two coils in a transformer. One coil is the primary coil, and the other is the secondary one. These are placed on the core of the transformer. The lamination of the cores is joined as strips.
There is a high mutual inductance between the coils. When an alternating current starts to flow through the primary coil, a varying magnetic flux is created. According to faradays law, the change in the magnetic flux induces an electromagnetic force. The electromagnetic force (EMF) is induced in the secondary coil, and the secondary coil is placed on the iron core, which also has the primary coil linked to it. This is called mutual induction.
The operations carried out by the transformers are as follows:
- The transfer of electrical energy from one circuit to a different one.
- The transfer of electrical power takes place through electromagnetic induction.
- Electric power transfer takes place without any changes to the frequency.
- Circuits are linked by mutual induction.
Part of a single-phase transformer
Core – it acts as a support to the windings in the transformer. Magnetic flux can flow easily through the iron core. To reduce losses in the transformer, the iron core is laminated.
Windings – there are two types of winding. These are the primary and secondary windings. The windings are made with copper wire due to the high conductivity, which minimizes power loss. Copper has very high ductility and can be drawn into thin wires. There is insulation between the windings. Insulation is necessary to prevent short circuits.
Insulation materials include insulating tape, oil, paper, and laminate made of wood.
An ideal transformer is a transformer with no losses.