Fast and Accurate Method for Dynamic Security-constrained Economic Dispatch via Sensitivity Analysis

A new approach which is fast and accurate for including the transient stability constraints in the optimal power flow is presented. The context is that of applications in economic dispatch with dynamic security constraints. The method draws on the sensitivity analysis of maximum relative rotor angles with respect to generator active-powers. The analysis is based on perturbations of the active-powers of individual generator units together with time-domain transient stability simulation for each perturbation to derive dynamic security constraints for including in the OPF. The constraints are linear inequalities expressed in terms of generator active-powers. The number of the constraints is relatively low, and equal to the number of generator units less one, with one generator being the reference generator. The time-domain transient stability simulations are performed outside the OPF calculation. The method proposed lends itself to the application of parallel computing for forming the dynamic security constraints.