Improvement of transient stability analysis methods in verification of wide area control systems for long-distance AC interconnection

Development of event‐based centralized excitation control method of synchronous generators for improving the transient stability

“…Here, T rem is the moment of fault recovery. Taking Equation (7) for example, if ω CM is positive at the time of fault recovery, that is, the critical machine is accelerating, then Δe f,k is set to make Δ ωCOI,CM negative so as to suppress first phase-angle swing in the critical machine.…”

“…Thus, excitation control using real-time measurement data was proposed. [5][6][7][8] These studies demonstrated that the use of real-time wide area measurement data produces a better stabilization effect as compared to existing excitation control systems; at the same time, it was pointed out that the stabilization effect declines with longer delays in measurement, communication, control calculation, and other processes. In addition to postevent emergency control, in which control actions are determined based on real-time measurement data, there is also pre-event emergency control (event-based emergency control), in which control actions are determined before a system fault occurs.…”

“…On the other hand, there has been progress recently in PMUs (Phasor Measurement Units) and other wide area measurement systems, as well as online information and communication technologies. Thus, excitation control using real‐time measurement data was proposed 5–8 . These studies demonstrated that the use of real‐time wide area measurement data produces a better stabilization effect as compared to existing excitation control systems; at the same time, it was pointed out that the stabilization effect declines with longer delays in measurement, communication, control calculation, and other processes.…”