Key Busbars and Vulnerable Busbars Identification Based on Voltage Sag Caused by Busbar Fault

In order to assess busbar voltage sags of power system to guide the planning,operation and transformation,busbar fault types and operation modes were considered,from two points of view,one point was the influence degree of busbar fault,and the other point was busbar influenced thing by other busbar fault,a group of indices to evaluate busbar voltage sags was presented,including busbar key degree indices and busbar vulnerable degree indices. and the best serious indices. With above indices,key busbars and vulnerable busbars could be found,operation mode,planning and transformation scheme could be evaluated. It is shown that the definition of indices is a useful approach to guide the grid planning,transformation and operation. An example is given showing that the proposed approach is feasible.