A power transformer works by converting electrical energy from one voltage level to another. It usually consists of two or more coils which are wrapped around a magnetic coil. This coil is also known as windings and has two parts; primary winding and secondary winding. The AC (alternating current) passes through the primary winding which creates a magnetic field around the winding. This generates voltage in the secondary winding which is transmitted to electrical devices connected to it. Usually, the number of turns on both the primary and secondary windings determines the power voltage between input and output. For example, if the primary winding has 100 turns and the secondary winding has 50 turns, the power voltage will be reduced at least by half in the secondary winding.
Here is a detailed explanation of how transformers operate:
- The core working principle of a transformer is electromagnetic induction which was discovered by Michael Faraday. When AC power flows into the primary winding, it creates a magnetic field around the coil. This, in turn, creates power voltage in the secondary coil which is transmitted to substations for use by consumers.
- A power transformer has two main components; a winding and a core. The core is made of laminated steel which is used to reduce power losses caused by eddy currents. The core is used to provide a path to the power generated before it is transmitted to substations. The winding is made of copper wires which are wrapped around the coil. There are two sets of winding; primary winding and secondary winding. The primary winding is connected to the power source while the secondary winding is connected to the output load.
- Once the AC voltage is passed through the primary winding, it generates a magnetic field in the core. This magnetic field is then passed to the secondary winding from where electricity is transmitted to users.
- In case the number of turns in the secondary winding is more than that primary winding, the output voltage is higher than the input voltage. If the number of turns in the secondary windings is lesser than the primary winding, then the output voltage is lower than the input voltage.
Power transformers are efficient devices, sometimes going upto 95% efficiency or more. They do face power losses due to the following reasons:
- Core Loss: This is caused either by eddy currents or hysteresis in the core material.
- Copper Loss: This loss is caused because of the resistance of the windings.
Common uses of power transformers include:
- Power Generation: Power voltage is stepped up so it can be transmitted over long distances.
- Power Distribution: The voltage is stepped down to manageable levels suited for homes and commercial purposes.
- Industrial Applications: Providing specific voltage levels for different industrial processes.
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