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 essentially delivering electrical energy, converted from primary energy sources, to the end users. The only clear separation 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 structure of the system is dependent upon the magnitude and the pattern of demand within the geographical area. It is also usual for transmission systems to be interconnected to enable shared economic benefits and operational access to generating capacity.

Chapter Contents:

• 1.1 Introduction
• 1.2 Development of transmission and distribution systems
• 1.2.1 Early developments (1880-1930)
• 1.2.2 The development of the transmission grid concept (1930-90)
• 1.2.3 Global developments
• 1.2.4 Recent developments 1990 to date (or 1990 onwards or post 1990)
• 1.3 Structure of transmission and distribution systems
• 1.3.1 Technical factors influencing the structure of transmission and distribution systems
• 1.3.2 Organisational structures
• 1.4 Design of transmission and distribution systems
• 1.4.1 Security of supply
• 1.4.2 Quality of supply
• 1.4.3 Stability
• 1.5 Operation of transmission and distribution systems
• 1.5.1 Operational planning
• 1.5.2 Extended real-time operation
• 1.5.3 Real-time operation
• 1.5.4 Post real-time operation
• 1.6 Future developments and challenges
• 1.6.1 Organisational developments
• 1.6.2 Technical and technological developments
• 1.6.3 Control and communication developments
• References

Inspec keywords: power system interconnection; transmission networks; distribution networks; power grids

Other keywords: delivery points; bulk transport; geographical area; economic benefits; primary energy sources; load centres; electric power distribution system; electrical energy; electric power transmission system; bulk power transfer; operational access; generation centres

Subjects: Power system management, operation and economics; Distribution networks