A New Algorithm for Transient Stability Emergency Control Based on Power Switching

Emergency control has become a necessary measure to maintain power system stability, for complexity of operating modern power system is continuously increasing. The basic idea proposed by this paper is to find a proper strategy to switch the unbalance power and achieve the goal of exhausting the superfluous energy, which drives system to be unstable. From the view of Newton´s second law, the unbalance power is the essential reason, which dominates transient stability. This paper firstly analyzes the relation between the unbalance power and transient stability, the effect of generator tripping. Then a new kind of criterion for transient stability assessment and an index for evaluating control measure are given. The algorithm proposed establishes the direct relation between the original system and controlled system. It doesn´t depend on mode identification and avoids blindfold searching. Cascading faults and multi-swing instability can be easily handled. The simulation performed on New England system has proved the rationality of the algorithm