Implementation of bus bar switching and Short Circuit Constraints in optimal power flow problems

The topology of an electric network heavily influences power system operations, power flows, short circuit currents and certain reliability aspects. While meshing increases reliability, it also increases the short circuit power, which can be a problem especially in highly meshed grids. Bus bar switching is often employed by the system operator for preventive and corrective actions, as it is a quasi-free control action. The introduction of binary variables, representative of the state of the circuit breakers, in the optimization description allows for bus bar switching resulting in the adaptation of the topology of a grid. The goal of this paper is to present an algorithm that is able to propose a topology that complies with the Short Circuit Constraints (SCC) whilst respecting the Power Flow Constraints (PFC). Both are adapted in such a way that they allow binary switching actions. The mathematical description of the optimization problem is a Mixed Integer Non Convex Quadratic Constraint Program (MINCQCP) and is implemented in AMPL using the Couenne solver. The paper concludes with two tests that show the functionality of the approach.