An Optimal Power Flow Function to Aid Restoration Studies of Long Transmission Segments

This paper presents an optimal power flow function for aiding restoration studies of subsystems having long transmission segments. The method simultaneously computes an optimal set of variables which are critical for the subsystem restoration: the generation power plant high-side voltage, the minimum shunt reactor configuration and the maximum load to be safely energized. A set of overvoltage restoration scenarios following load rejection is constructed in such a way that the computed shunt reactor compensation becomes distributed along the transmission corridor. The whole problem is formulated as a single optimization problem whose solution is obtained by an optimal power flow, based on the Primal-Dual Interior Point Method. The described results for a restoration study on a system from practice confirm the effectiveness of the proposed method.