Stability of a synchronous machine due to multiple faults in unbalanced power systems

The authors investigate the dynamic behavior of a synchronous generator connected to an unbalanced three-phase power system which is subjected to a shunt fault at one location and blown fuses or open conductors at another location. The method involves phase frame representation of the line. The unbalance created by large single-phase loads, untransposed lines, conductor bundles, etc., is reflected in polyphase impedance matrices. Consequently, line removals, additions, impedance changes, and conductor and faulted phase openings can be simulated based on the boundary conditions. Thus the proposed method makes it possible to study the synchronous generator stability due to any combination of single or multiple unsymmetrical series and shunt faults occurring anywhere in the system and the result of several case studies are presented.<>