POWER SYSTEM CONFERENCE FAST DYNAMIC SECURITY ASSESSMENT OF POWER SYSTEMS

Steady-state and dynamic instabilities cause problems in the cleetdcalpower systems afl over the world. Meanwhile, generation reserves are gradualty decreasing due to economical and environmental points of view. This motivates instability to occur not only during major disturbances but also under slow varfing changes of the load. Therefore, fast dynamic security assessment is of great concern for sound operation of a large scale power system. In this paper, fast assessment of dynamic security is divided into two main categories: maximum loadabitity and dynamic security index. The first one involves the evaluation of the maximum loadabifity of everyg network topology without losing the small signal stRbgity . The second one refers to the assessment of a wefl-deined cdted as the dynamic security index which determines the relative stabWty of every operating point. For the assessment of maximum londabifity, a reliable and accurate approach is presented which is bsed on the static equivalencing of the network for finding initial values and eigenvalue analysis by the 19-Matril mebtod in order to evaluate the dynamic stabifity of dillerent operating condidon& For the dynamic security index, a global methodology for fast assessment of small signal stability based on the AESOPS adgoilthm has been presented. In summar the proposed methods show some advantages overT,the previbuse established methods as to CPU dme required without undue loss of accuracy.