A Hybrid Decomposition Method for Transient Stability Assessment of Large Power System

Transient stability poses challenging computational and analytical problems due to its non-linear nature. At the planning stage more stability runs are possible if transient stability evaluation is faster. SIME (Single Machine Equivalent) is a method which transforms the dynamics of multimachine power system into single machine which is then analysed to find whether the system is stable or unstable. The instability is detected at an instant before the system actually goes unstable. Suitable control actions can now be taken within this margin so as to make the system stable. SIME uses best features of Time Domain method and Direct Method to carry out transient stability analysis. The Simulation is done for a contingency and critical clearing time and stability margin are found. The technique is tested on 50 machine IEEE test system. If instability is detected Generation scheduling is done to stabilize the system. The transient stability programme is implemented on MATLAB-6.5.