Transient stability analysis of power system using BCU method and ray technique

In this paper stability analysis of a power system is carried out for three machine systems. The energy function is developed mathematically and potential boundary is formed by using ray method. By forming the fault trajectory, exit point on the boundary is estimated and then taking this exit point as an initial value, Newton´s optimization technique is applied to find the controlling unstable equilibrium point (c.u.e.p). This provides the critical energy for that fault contingency. By this method with the knowledge of fault energy injected into the system during fault, severity is predicted and the critical clearing time is found for safe operation.