Transformer is an electrical device which transfers electrical energy from one circuit to another using conductors or transformer coils. Transmission and Distribution of energy from generation point to distribution is vital. Generally, two most widely used transformers are Step-up and Step-down.
The Step-Up transformer increases incoming voltage of power when it is passed through it. These transformers are widely used at electricity generation point. This is due to the fact that higher voltage moves faster with least loss of energy. (Voltage in India is fixed at 400 KV at generation point). Since power has to travel long distances it facilitates to travel at a faster and at efficient rate.
Step-down transformer decreases extent of incoming voltage when passed through it. These transformers are used at distribution points. Voltage in India is stepped down consistently after several stages from 400Kv-132 Kv-33Kv and ultimately to 433/250 Volts.
How Does a Transformer Work?
Transformer uses coils to transfer electrical energy between the circuits. As a result of current-variations in Primary Winding (HT) a magnetic flux is generated in the core of transformer which then results in the magnetic field of varying extent through secondary winding (LT). The variations in magnetic field induce varying EMF or electromotive force or voltage in secondary winding.
When you connect a load to the secondary winding, the current will flow through it and electrical energy is transferred to the load through transformer coils. The ratio of induced voltage in secondary winding (Vs) to primary voltage (Vp) is represented by the ratio of secondary (Ns) to the primary turns (Np) through following equation;
Vs/Vp = Ns/Np
A transformer selects the ratio of turns and accordingly “steps up” or “steps down” AC, or Alternating current voltage.
When Ns > Np the transformer “steps up” while when Ns < Np its value is stepped down. |
