Modifications And Applications Of Dynamic Security Region Algorithm Based On SIME Method

With the rapid development of smart grid,the complexity of power system is increasing and the importance of study of transient stability is emphasized.Dynamic stability region(DSR),among numbers of algorithms,can evaluate the system as a whole and simplify control algorithm.Almost all improved DSR algorithms include the calculation of critical active power injection vector.The traditional dichotomy method only uses information as zeros and ones about stability.In order to introduce stability margin into searching process,a non-linear map model is presented between n-dimensional space of active power injection and mechanical power of one-machine infinite-bus system.This model make the combination of SIME method and DSR method possible.Then the second order convergence rate can be obtained.Considering that one-sided approximating method is of great rapidity,a modified Newton method is proposed which can increase the calculation speed further.Besides,contingency screening and ranking method,based on probabilistic insecurity index,is an important application of DSR algorithm.The method proposed in this paper is conducive to the on-line application of contingency screening and ranking.Moreover,after the integration of large-scale wind power,the volatility of wind power would influence the effectiveness of generator trip inevitably.Thus,this paper propose an expected loss model considering volatility of wind power and load.This model evaluates economy,uncertainty of faults and volatility which makes contingency screening and ranking method rational and accurate.