Power system basics

Abstract

The generation, transmission, and distribution of the electricity is the business of the large utility companies, being performed through complex networks of interconnected generators, transformers, transmission lines, control, monitoring, measurement, and protection equipment, developed over a century. The chapter starts with a brief power system description and presentation, some details on major power system components, and functions. Various fuels (e.g., coal, natural gas, oil, nuclear energy, or water power) or energy sources (e.g., wind energy, solar energy, ocean energy, or geothermal energy) are used to generate electricity in modern power systems. Most of the modern power systems are three-phase, as it enabled more efficient and economical energy generation and transmission to the users. Power is changed from three-phase to single-phase only for consumers living very near. However, the power distribution is usually changed from three-phase to single-phase networks near consumers (end-users). In modern power systems, the generator voltages are transformed into high voltages for the efficient and economic transmission at long distances, then the voltages are lowered to the levels required by the consumers near the industrial and residential locations. The chapter also contains a brief introduction on the per-unit system, a very useful tool to simplify calculations and analysis of the power system. A brief discussion of the frequency characteristics and issues is the focus of the last section of the chapter. The chapter topics are the basics to understand the electric motor, transformer, and generator operations and characteristics, so it is vital that the readers must have good understanding of three-phase and per-unit systems and must be able to apply them.