Preventive control of transient stability in power system using trajectory sensitivities

In this paper, the problem of transient stability preventive control is partitioned into two sub- problems, namely optimal power flow (OPF) problem and transient stability control, such that they could be solved in turn using an iterative approach. For each transient unstable contingency, trajectory sensitivities based generation rescheduling is performed to regain the system stability. Instead of using approximated initial values, new expressions for the trajectory sensitivities of algebraic variables have been derived to obtain their accurate initial values. Furthermore, a largest rotor angle criterion under the COI reference frame is adopted to determine the critical order of generators. Results obtained from the WSCC 3-machine 9-bus and New England 10-machine 39-bus systems have validated that the proposed method is practical and effective.