Ambient data driven sensitivity-based active power scheduling for enhancing the small-signal stability of large-scale interconnected power systems

Appropriate selection of the rescheduled generators and the determination of redispatch amount are the basis for realizing the effective enhancement of interarea mode damping through active power scheduling. A refined generation rescheduling strategy to enhance interarea mode damping relying solely on synchrophasor ambient measurements is presented. First, on the basis of the estimation of measurement-based maximum allowed interarea transmission power (MAITP) considering small signal stability (SSS) constraints, the required minimum rescheduling amount capable of increasing the poorly damped mode to SSS constrained security boundary is given. Second, taking advantage of random fluctuations of both ambient measurements and corresponding damping ratio estimations, a perturbation-based sensitivity method is proposed, which effectively assists in selection of the candidate generators for rescheduling. Based on the selected candidate generators and the total redispatching amounts, a refined rescheduling strategy considering generator regulation capacity and redispatching feasibility is further developed. The proposed scheme enables online improvement of interarea modes damping with the least adjustment cost. The effectiveness of the proposed strategy has been demonstrated by numerical simulation cases and the simplified Northeast China power grid.