What is the primary purpose of a transformer in an electrical system?

The primary purpose of a transformer in an electrical system is to step voltage up or down. Transformers operate on the principle of electromagnetic induction and are designed to change the voltage level while maintaining the same frequency of the electrical signal.

When an alternating current (AC) flows through the primary coil of a transformer, it generates a magnetic field that induces a voltage in the secondary coil. Depending on the turns ratio between the primary and secondary coils, the transformer can either increase (step up) or decrease (step down) the voltage. This ability is crucial for efficiently transmitting electricity over long distances, as higher voltages can minimize energy loss due to resistance in the wiring.

While storage of energy is vital in power systems, transformers do not perform that function. They do not convert AC to DC since that role is assigned to rectifiers. Additionally, while transformers can provide some level of circuit protection by adhering to design and operational parameters, they are not primarily designed for that purpose. Instead, circuit protection is typically handled by devices like fuses or circuit breakers. Therefore, stepping voltage up or down is the fundamental role that accurately defines the operational significance of transformers in electrical systems.