An Automated Transient Stability Constrained Optimal Power Flow Based on Trajectory Sensitivity Analysis

This paper presents an automated transient stability constrained optimal power flow (ATSC-OPF). ATSC-OPF automates the design of linear transient stability constraints without online human interference thus is adaptive to the change of real-time operating conditions and suitable for applications in industrial dispatch programs. The design of transient stability constraints uses trajectory sensitivities to separate the integration of time-domain simulation from the online computing of optimal power flow. For identified unstable cases, a generic iterative algorithm is proposed to search corresponding stable base cases required to calculate trajectory sensitivities. ATSC-OPF identifies and limits only the key generators at critical time to minimize the extra computational burden brought by the transient stability constraints. The designed transient stability constraints are incorporated into ATSC-OPF only when needed in operation. The limits in the transient stability constraints are determined with manageable stability margin to avoid unnecessary increase of operational cost. The performance of ATSC-OPF is studied with the New England 39-bus system for a single-contingency situation and a 140-bus simplified NPCC system for a multicontingency situation.