What is a power system? Simply put, a power system consists of three (or more) components. These components are an energy generation device, transmission device, and an outlet or receiver device.
An electric power system consists of several different elements. An obvious example of such a system is the electric grid, which provides electric power to industry and homes over an extended region. The grid typically consists of several large power plants with large transmission lines. There are also many small power plants spread out along the region in question.
A transmission line is used to convey electric energy from a power plant to a desired location. The most common types of lines are electrical poles or cables. For our figure 1 example above, the electric energy would be transmitted via a number of long, wide wires (like the cables in your home). And these wires would be controlled by a single control center. This single control center would typically have several units. Each unit could be a substation or it could be an individual plant.
substations are basically units which receive and transmit electric power into their assigned destinations. A substation can either be built inside of an existing building or it can be constructed outside. In our figure 1 scenario, the substation would need to be located indoors so that there would be no interference from external sources. Units within the substation could be single units or they could be multiple units. The size of the substation determines the voltage levels, it can safely handle.
Electricity flows through transmission lines at very high voltages. To protect the integrity of the electric power grid, protection is offered by safety-level connections between the transmission lines and the substations. The safety-level connections are designed to limit the amount of energy flowing from the transmission lines to the substation. The energy limit is typically in the form of ground-level voltage. For this reason, a separate safety-level connection is required for each separate substation. This connection is typically made between the transmission lines and the substation.
There are three different types of power distribution systems. These include powerline (which delivers electricity to the consumer), distribution system (which delivers the voltage between the consumer and distribution lines) and centralised systems (which provide the entire voltages between distribution lines and the consumer’s device). Powerline distribution systems are often used in rural areas and to deliver higher voltage levels. Distribution systems on the other hand are used more often in metropolitan areas to supply medium voltage.