Multilevel distributed approach for DC Optimal Power Flow

The interest in distributed control methods for power systems is motivated by the need for scalable solutions to handle the coordination of an increasing number of distributed resources. This paper presents a fully distributed multilevel method to solve the DC Optimal Power Flow problem (DC-OPF). Our proposed approach constitutes a distributed iterative mechanism to solve the first order optimality conditions of the DC-OPF problem using the fact that optimality conditions involve local variable couplings. The proposed distributed structure requires each bus to update a few local variables and exchange information with neighboring buses. Our multilevel distributed approach distributes the computation at several levels, i.e., nodes, subareas and areas. It allows for synchronous information exchanges, i.e., after each iteration, at the nodal level and asynchronous communication, i.e., after multiple iterations, between subareas and areas. To define meaningful subareas, we are using a graph theoretic partitioning method derived from an epidemics model. We compare the performance of the proposed partitioning method over a random partitioning method using the IEEE 118-bus system.