Transient stability preventive control with optimal power flow

The dependence on electric power has been ever increasing and power outages have many social and economic influences. Therefore, preventive control on normal operating conditions becomes important and will be more desired in power system operations. In this paper, we pay attention to one of the most important indices for transient stability, critical clearing time (CCT), and propose a new transient stability preventive control method using optimal power flow (OPF). A preventive control to achieve a more stable power system operating point is carried out by generator output rescheduling and generator terminal voltage control, which are determined using the linear relationship between CCTs and the generator rotor angles, and also between CCTs and the active powers of transmission lines. The validity of the proposed method is shown by simulation studies. It is shown that the proposed method can make CCTs of severe contingencies longer than the target values.