In this topic, you study Power System – Definition & Structure of Power System.
The power system is an electrical network that delivers real-time electrical energy to the consumers. Thus, an electric power system consists of three main sections – the generating, the transmission and the distribution, as shown in Figure 1.
Figure 1. Power System overview.
Structure of Power System
The function of an electric power system is to connect the generating station to the consumer’s premises with the help of various interconnected systems such as generating stations, transmission lines, loads, etc. Fig. 11 illustrates a schematic line diagram of a very simple electric power supply network. As shown in the diagram, the electrical energy is generated by large generators or alternators, usually 11 kV and 33 kV. Here, this voltage stepped upto 200kV, 400 kV or more by means of large transformers. At this stage, the electrical power is transmitted to a bulk power substation, where this power is supplied from several power stations. The voltage at these substations stepped down to 66 kV and fed to distribution substations for the onward transmission. Now, the voltage is further stepped down to 33 kV and 11 kV for large and medium industrial consumers at the primary distribution level. Finally, the voltage is stepped down at the secondary distribution level of 400 V three-phase and 230 V single-phase with the help of distribution transformers for small consumers.