As technology is advancing the consumptions of power is steadily rising. There are three steps for proper electrification these are: electric power generation, transmission and distribution. This three are equally important for proper electrification, without any one of this three the electricity system will be incomplete. Power Grid Company ltd is the BPDB (Bangladesh Power Development Board) wound company which is the only authorized company for the Electric Power Transmission sector in Bangladesh. Rural Electrification Board (REB) has many substations all over the country which are connected through the distribution line, these stations are called substation.
A short transmission line is defined as a transmission line with an effective length less than 80 km (50 miles), or with a voltage less than 69 kV. Unlike medium transmission lines and long transmission lines, the line charging current is negligible, and hence the shunt capacitance can be ignored.
A medium transmission line is defined as a transmission line with an effective length more than 80 km (50 miles) but less than 250 km (150 miles). ... The ABCD parameters of a medium length transmission line is calculated using a lumped shunt admittance, along with the lumped impedance in series to the circuit.
A long transmission line is defined as a transmission line with an effective length more than 250 km (150 miles). Unlike short transmission lines and medium transmission lines, it is no longer reasonable to assume that the line parameters are lumped.
