Restoring solutions for unsolvable cases via minimum load shedding for a specified direction

This paper focuses on a methodology to determine corrective adjustments on the electric power network when the steady-state power flow equations have no real solution. The proposed approach is based on the nonlinear version of the predictor-corrector primal-dual interior point optimization algorithm. The active and reactive power loads are parameterized. They are expressed in terms of a base demand, a pre-specified rate of load decrease (here called specified direction) and a load parameter. The demand factor and the specified direction indicate the amount of load to be curtailed. The optimization problem consists of minimizing this factor, so that the solution of the power flow equations is restored. The operational limits of the power system are modeled as inequality constraints. Results obtained for three real networks of 352, 749 and 1916 buses, equivalent to the Brazilian South-Southeast power system, illustrate the performance of the proposed technique.