Optimization Method of Security Control Strategy for Dynamic Stability in Interconnected Power Grid

It may lead to low frequency oscillation in interconnected power grid if part of the lines of power transmission section are disconnected. Reducing the output of generators in sending end urgently is an effective measurement to restrain oscillation, and different control strategy may lead to different effect. The damping of generators' control system and its electrical distance to the receiving end are the two important factors which impact the effect of generators tripping. The factors above are quantified respectively by damping contribution and voltage phase angle difference of nodes in this paper, and they are weighted to order according to priority of generators tripping. The damping contribution accumulates the effect of damping torque segmentally by decoupling the electromagnetic torque to synchronous torque and damping torque. The actual power grid system of North China is used to verify the correctness of the method. By comparing the existing security control strategy with the result of the proposed method, it shows that the method in this paper can optimize control performance and reduce control cost. Therefore, this method has some practical value.