In this tutorial, we will learn how an electrical transformer works. The working of transformer is one of the important concepts that we should understand while working as an electrical engineer.
As we know, an electrical transformer is one of the most widely used electrical machines in the field of power transmission and distribution. It is used for changing the voltage level in the system i.e., to increase or decrease the voltage levels.
Let’s now understand the operation of a transformer in detail.
How does a Transformer Work?
To understand the working of a transformer, let us consider the following schematic diagram of a single-phase transformer.
In this transformer diagram, an alternating voltage V1 is applied to the primary winding. This applied voltage sets up an alternating flux ϕ in the core. This alternating flux links both primary and secondary windings magnetically.
Also, the alternating flux ϕ induces an EMF E1 in the primary winding and EMF E2 in the secondary winding due to electromagnetic induction. Here, E1 is called primary EMF and E2 is called secondary EMF.
According to Faraday’s law of electromagnetic induction, we have,
$$E_1=-N_1 \frac{dϕ}{dt}$$
$$E_2=-N_2 \frac{dϕ}{dt}$$
Therefore,
$$\frac{E_2}{E_1} =\frac{N_2}{N_1}$$
From this equation, it is clear that the magnitudes of E1 and E2 depend on the relative number of turns in primary and secondary windings.
In a transformer,
- If N2 > N1, then E2 > E1. In this case, the output voltage is greater than the input voltage. This kind of transformer is referred to as a step-up transformer.
- If N1 > N2, then E1 > E2. In this case, the output voltage is less than the input voltage, and this type of transformer is called a step-down transformer.
Now, if an electrical load is connected across the secondary winding, then a current I2 will flow through the load. This is how a transformer works and enables us to transfer power from one AC circuit to another with a transformed voltage level.
Conclusion
So, this is all about the working of a transformer. If you have any questions about this topic, kindly post in the comment section. I will try to answer as soon as possible.