SYSTEM OVERVIEW

Electric power systems are real-time energy delivery systems. Real time

means that power is generated, transported, and supplied the moment you

turn on the light switch. Electric power systems are not storage systems like

water systems and gas systems. Instead, generators produce the energy as

the demand calls for it.

Figure 1-1 shows the basic building blocks of an electric power system.

The system starts with generation, by which electrical energy is produced in

the power plant and then transformed in the power station to high-voltage

electrical energy that is more suitable for efficient long-distance transportation.

The power plants transform other sources of energy in the process of

producing electrical energy. For example, heat, mechanical, hydraulic,

chemical, solar, wind, geothermal, nuclear, and other energy sources are

used in the production of electrical energy. High-voltage (HV) power lines

in the transmission portion of the electric power system efficiently transport

electrical energy over long distances to the consumption locations. Finally,

substations transform this HV electrical energy into lower-voltage energy

that is transmitted over distribution power lines that are more suitable for

the distribution of electrical energy to its destination, where it is again transformed

for residential, commercial, and industrial consumption.

A full-scale actual interconnected electric power system is much more

complex than that shown in Figure 1-1; however the basic principles, concepts,

theories, and terminologies are all the same. We will start with the basics

and add complexity as we progress through the material.