抄録
This paper proposes a new dynamic preventive control strategy for maintaining power system security, considering both of transient and mid-term stabilities. While the authors have already presented preventive control strategies for transient stability, a new problem has occurred recently regarding mid-term instability in which some generators lose synchronism after 10 second or more from a fault clearance. It becomes clear that the cause of the instability is mainly post-contingency dynamic steady state instability. First, this paper shows a preventive control strategy for improving the mid-term stability using a dominant eigenvalue of post-contingency equilibrium point. Further, this paper presents a unified dynamic preventive control algorithm which can maintain both stabilities together. In this algorithm, the time domain for each stability problem is considered appropriately and the difference between the clasical model and the detailed model is analyzed in detail. The effectiveness of the proposed method is examined by numerical examples for a model system.
