A mixed-integer LP-based network topology optimization algorithm for overload alleviation

Line switching is used in power system operation to alleviate branch overloads. This paper presents a mixed-integer linear programming algorithm that determines the optimal switching strategies to remove or reduce overloads within a power system. It has been formulated as an iterative process that opens one branch in each iteration. Each iteration comprises two steps. First, the best switching candidates for each overloaded branch are identified. Then a mixed-integer linear optimization program is formulated to select the branch to be opened. The algorithm represents the network with the linear DC power flow model, where a branch reactive power flow is taken approximately into account by reducing its branch rating in proportion to the power factor. The performance of the method is illustrated with an actual scenario of the Spanish power system.