Electric power transmission and distribution systems

Abstract

Today, in all countries in the world that utilise electricity as an efficient source of light and energy, some form of a transmission and distribution system exists. Both systems carry electric current, albeit at different voltages and they are connected to each other. They are part of the bulk transport and distribution system that essentially delivers and distributes the electrical energy, converted from primary energy sources, to the end users. The only clear differences between the two systems is based on the perception of their end use and functionality. Transmission systems provide the bulk transport paths for electrical energy from generation centres located close to the primary energy sources to the major load centres within a large geographical area, thus facilitating economic and efficient bulk power transfer. On the other hand distribution systems are concerned with the delivery of electrical energy to individual customers within a smaller geographical area. In this respect a distribution system may have a number of delivery points to its major load centres, from one or more transmission systems and/or elements of a transmission system, the final shape of the system structure being dependent on the magnitude and the pattern of demand within its geographical area. It is also usual for transmission systems to be interconnected to enable shared economic benefits and operational access to generating capacity.