This paper proposes a monitoring and control method for transient stability (TS). First, it is clarified that there may exist various critical patterns of uncertain power flows causing instability due to photovoltaic generations. Then, the use of critical clearing time (CCT) is suggested as a TS index, which can be computed by conventional TS analysis tools. A distribution factor (DF) for controlling CCT is investigated, referred to as CCT-DF in this paper. Then, three optimization problems using CCT-DF are formulated based on bilevel optimization to obtain reliable operation planning. The combined use of the optimizations guarantees the power system robust security under uncertainties.
K E Y W O R D Scritical clearing time, photovoltaics, transient stability, uncertainty 8