Optimal operation solutions of power systems with transient stability constraints

The computation of an optimal operation point in power systems is a nonlinear optimization problem in functional space, which is not easy to deal with precisely, even for small-scale power systems. On the other hand, the emergence of competitive power markets makes optimal power flow (OPF) with transient stability constraints increasingly important because the conventionally heuristic evaluation for the operation point can produce a discrimination among market players in the deregulated power systems. Instead of directly tackling this tricky problem, in this paper, OPF with transient stability constraints (OTS) is equivalently converted into an optimization problem in the Euclidean space via a constraint transcription, which can be viewed as an initial value problem for all disturbances and solved by any standard nonlinear programming techniques adopted by OPF. The transformed OTS problem has the same variables as those of OPF in form, and is tractable even for the large-scale power systems with a large number of transient stability constraints. This paper also derives the Jacobian matrices of the transient stability constraints and gives two computation algorithms based on the relaxation scheme. The numerical simulation verified the effectiveness of the proposed approach.