Damping estimation for multi-swing transient stability analysis: the OMIB case

The main concern of this paper is to create a methodology that, if incorporated to the BCU method of transient stability analysis, one can assure, for the one-machine-infinite-bus system (OMIB), the stability of the system and not the existence of the first swing only. The methodology constitutes in determining, in an iterative way, a critical damping coefficient that should be associated to the system, so that it is assured that the saddle points used as the controlling equilibrium point are on the boundary of the corresponding attraction area. That is, with that damping coefficient in the system, it can be assured that the one-parameter transversality condition will be satisfied. The methodology, as developed, is an iterative monotonically convergent process very easy to implement and does not require knowledge of fault trajectory at all. An example showing how the methodology works is also incorporated in the paper. The proposed methodology was also applied to a simple multimachine system. In that case however, the proposed methodology needs further studies and adaptation in order to be applied