How do transformers work in the National Grid?

Transformers in the National Grid change the voltage of electricity to ensure efficient transmission and safe distribution.

Transformers are essential components in the National Grid, which is the network that delivers electricity from power stations to homes and businesses. They work on the principle of electromagnetic induction and consist of two coils of wire, known as the primary and secondary coils, wrapped around a magnetic core. When an alternating current (AC) flows through the primary coil, it creates a changing magnetic field, which induces a voltage in the secondary coil.

There are two main types of transformers used in the National Grid: step-up transformers and step-down transformers. Step-up transformers increase the voltage of electricity generated at power stations. This is crucial because higher voltages allow electricity to be transmitted over long distances with minimal energy loss. For example, electricity might be stepped up to 400,000 volts for transmission across the country.

Once the high-voltage electricity reaches a local substation near the area where it will be used, step-down transformers reduce the voltage to safer, more usable levels. For instance, the voltage might be reduced to 11,000 volts for distribution within a town and then further stepped down to 230 volts for use in homes and businesses.

Using transformers in this way makes the National Grid more efficient and reliable. High-voltage transmission reduces energy loss due to the resistance of the wires, which means more of the generated electricity reaches its destination. By stepping down the voltage before it enters homes and businesses, transformers ensure that the electricity is at a safe level for everyday use, preventing damage to appliances and reducing the risk of electrical hazards.

In summary, transformers play a vital role in the National Grid by adjusting the voltage of electricity to optimise transmission efficiency and ensure safety for end users.