Optimal power flow with synchronous generator capability curves using the branch flow model

A method for incorporating synchronous generator capability curves (GCC) into the constraints of the optimal power flow (OPF) problem is proposed. The steady-state equivalent circuit of the synchronous machine in qd variables is added as a branch in the branch flow model (BFM) of the power system equations. Second-order cone programming is used to formulate a computationally efficient, convex relaxation of the BFM-based OPF with the GCC constraints. This enables the inclusion of nonlinear GCC equations, which vary with terminal voltage magnitude and include the impact of rotor saliency and stator resistance, in the OPF. Numerical verification and case studies are provided. • Detailed synchronous generator capability curves are incorporated in OPF problem. • The branch flow model is used to formulate an SOCP relaxation of OPF with GCCs. • The impact of varying terminal voltage magnitude on the shape of the GCC is modeled. • Effects of rotor saliency and stator resistance in field current limit are modeled. • Limits imposed by UEL controls in the underexcited region are captured.