The impact of wind power generation to enhance the power system security level following a line contingency has been investigated in this book.The optimal power flow (OPF) model and contingency constraint optimal power flow (CCOPF) model with Fixed speed wind turbine generating unit (FSWTGU) are developed.The FSWTGU is modelled as PQ bus in investigating its impact on power system security analysis.Determinations of the most severe contingency scenarios have been performed based on the contingency selection and ranking process.An artificial bee colony (ABC) based optimization algorithm is used for solving the OPF model. The proposed algorithm was tested on IEEE-30 bus system.