Line outage contingency analysis including the system islanding scenario

The paper describes an algorithm for determining the line outage contingency of a line taking into account of line over load effect in remaining lines and subsequent tripping of over loaded line(s) leading to possible system split or islanding of a power system. The optimally ordered sparse [B′], [B″] matrices for the integrated system are used for load flow analysis to determine modified values of voltage phase angles [δ] and bus voltages [V] to determine the over loading effect on the remaining lines due to outage of a selected line outage contingency. In case of over loading in remaining line(s), the over loaded lines are removed from the system and a topology processor is used to find the islands. A fast decoupled load flow (FDLF) analysis is carried out for finding out the system variables for the islanded (or single island) system by incorporating appropriate modification in the [B′] and [B″] matrices of the integrated system. Line outage indices based on line overload, loss of load, loss of generation and static voltage stability are computed to indicate severity of a line outage of a selected line.