Transient Stability of a Multi-Machine Power System Part I: Investigation of System Trajectories

Direct methods of transient stability analysis of a multi-machine power system, using a function describing the system´s transient energy, are discussed. By examining the trajectory of the disturbed system, the following fundamental questions are dealt with: the concept of a controlling unstable equilibrium point (u.e.p.), the manner in which some generators tend to lose synchronism, and identifying-the energy directly responsible for system separation. Resolving these issues will substantially improve transient stability analysis by a direct method.