A.C. Distribution

       In earlier days, d.c. system was used for the generation, transmission and distribution of electrical energy. But in case of d.c. system the voltage level cannot be changed easily unless we used rotating machinery which may not prove to be economical in many cases. This is the major disadvantages while working with d.c.

       Later on with the development of transformer, a/c/ system has become predominant. Now days a large power systems in the world are using a.c. system rather than d.c. because of many advantages of a.c. system.

       The transmission of electrical energy generated in the power station is at very high voltage with the use of 3 phase, 3 wire system. These voltages are stepped down for distribution at the substations. There are mainly two parts of the distributor system. They are primary distribution and secondary distribution. The voltage level of primary distribution system is higher than general utilization level. The secondary distribution systems receive power from primary distribution systems through distribution transformers. By distribution transformer voltage is stepped down to the normal working level and the consumers get the power with the voltage 400/230 V. The very commonly used a.c. distribution system is three phase four wire system as studied earlier.