ABSTRACT
ABSTRACT: It is a positive way to beautify the environment, improve the distribution reliability and ensure the safety of urban to change the overhead lines to underground. Anyway, it can effectively relieve the power limit caused by lack of land. So changing the overhead lines to underground cables becomes an important step to develop the city. As facts, cost is the core focused by government and enterprises, also an important fact considered during the cabling into underground. By using safety economics and input-output theory, this paper states underground space safety efficiency and evaluates index system to optimize the grid structure, power supply and economic goal and provides several suggestions.
