Transient Stability‐Constrained Optimal Power Flow (TSC‐OPF)

Abstract

Power system transient stability is concerned on the ability of the power system to maintain synchronism among synchronous generators when subjected to a large disturbance. In terms of its control, it can be divided into preventive control and emergency control according to different intervention timings. The former acts prior to the occurrence of the contingency (disturbance), which commonly refers to changing the system's operating point to make it able to withstand possible severe disturbances. The latter one, if necessary, is activated at the post-contingency states to mitigate the development of the possible instability evolution, which usually refers to load shedding or generator(s) tripping. For advanced protection of the power system against transient instability, both control actions are necessary, but the first line of defense is considered preventive control. For the sake of trading the economic purpose and the transient stability requirements in the deregulated power system operation environment, today's preventive transient stability control is usually realized by solving an optimal power flow (OPF) model considering stability constraints, yielding transient stability-constrained-optimal power flow (TSC-OPF), by which the system operating point can be optimized to meet a pre-defined objective function while simultaneously be able to withstand severe contingencies. As an effective preventive countermeasure, TSC-OPF implementation may usually advocate expensive cost since it usually refers to the active power output rearrangement among generators. It's of great interest to system operators and power market participants to depress the cost as large as possible, namely, higher-quality and efficient solutions to TSC-OPF are demanded remarkably. Due to the highly nonconvex and nonlinear properties of power system transient stability, the computation of TSC-OPF is quite intractable, even for a small-scale power system. In literature, various methods have been proposed to solve the TSC-OPF in a relatively effective way. In this chapter, a comprehensive review of the classic TSC-OPF solution methods is presented, and the advantages and disadvantages of each kind are identified, trying to provide more valuable insight into this area.