Optimal Load Shedding in Electric Power Grids

We consider the optimal load-shedding problem in electric power systems where a number of transmission lines are to be taken out of service. The nonlinear power flow equations and the binary decision variables lead to a mixed-integer nonlinear program. We show that the load-shedding problem has separable structure that can be exploited by using the alternating direction method of multipliers. We show that the subproblems in the alternating method can be solved efficiently. Numerical experiments with the IEEE 118-bus test case illustrate the effectiveness of the developed approach. Our computational results suggest that removing transmission lines between load buses results in less load shedding.