A transformer is an electrical piece of equipment used in electrical circuits to alter the voltage of the electricity flowing in a circuit by either increasing the voltage (stepping up) or decreasing the voltage (stepping down) (Pansini, 1999). Alternatively, they may be described as static machines which transform power from one circuit to another while maintaining the electrical frequency constant. Transformers are, therefore, very important devices in the distribution of electricity. There are two main reasons why transformers are important in the process of electricity distribution: “Stepping up” and “stepping-down.”
First, once produced at the power station, the electric current is at a low voltage level which would lead to high energy losses during distribution over long distances. Less electrical energy is lost is the electrical voltage is high. Some of the electrical current is lost in the form of heat and overcoming resistance. The power transmitted across a power line is a product of voltage and current (Pansini, 1999). The higher the voltage level, the lower the current level for delivery of constant power. High voltages are required for the delivery of low power. To obtain high voltages and low currents, “stepping-up” must be done. After production, step-up transformers are used to increase the voltage level for long-distance transmission.
Secondly, “stepping-down” must be done for the electric current to be usable in homes, offices etc. The high voltage electricity in long-distance power lines must be lowered for it to be usable in homes or offices for lighting and for electrical devices and equipment such as electronics, heating appliances, cookers etc (Pansini, 1999). This is using a step-down transformer.
This implies that, in electricity distribution, transformers are used in increasing electrical voltage for long distance transmission (“stepping-up”), and for decreasing the voltage for home and office consumption (“stepping-down”).
Pansini, A. J. (1999). Electrical transformers and power equipment (3rd ed.). Lilburn, Ga.: Fairmont Press.