Economic Comparison of AC and DC Distribution System

Two factors are the key problems in economic comparison of AC and DC distribution system which are equipment investment and transmission loss. In this paper, both investment of main equipment and transmission loss are considered. What is more the cost of operation and maintenance is taken into account. The load in the distribution network is classified and three application scenarios are raised which are DC load concentration area, industrial area and urban commercial and residential areas. Basing on investigation data, the DC load proportion in scenarios above are 75%, 50% and 60% respectively. Taking distribution network with typical topology structure, economic comparison is performed. Research results show that both maximum transmission capacity and initial investment cost of DC distribution network are higher than those of AC distribution network; the transmission loss of DC distribution system is lower than that of AC distribution system; the greater percentage the DC load is, the lower the total cost of DC distribution network will be.