Exploiting Power Line for Communication Purpose: Features and Prospects of Power Line Communication

The Power Line Grid

The power line grid is the largest network connecting urban, sub-urban and rural places with nearly 100% electrification in some countries and even in some rural areas. Depending on voltage levels, the grids can be divided into high voltage (HV), medium voltage (MV), and low voltage (LV) lines as shown in Figure 1. Electricity is generated at the generating station and transmitted at HV over overhead lines to long distances for nationwide and even international transfers. In the distribution stage, the HV is first step down to MV via primary transformer substations (PTS) and distributed to towns, cities and industrial complexes through buried or overhead cables. Finally the MV is stepped down to LV through a secondary transformer substation (STS) and distributed to the end users. Electricity usually enters a customer’s premise through a house access point (HAP) followed by an electric meter and a distribution box. The grid structures vary from country to country in terms of length of the LV line, number of homes reached by each line, voltage levels and method of injection. These pose a problem in generalizing the construction of PLC system and have been discussed in later sections.

Figure 1.

Generic power line grid and power line communication system