This paper proposes a fully distributed reactive power optimization algorithm that can obtain the global optimum of non-convex problems for distribution networks without a central coordinator. Second-order cone (SOC) relaxation is used to achieve exa
ct convexification. A fully distributed algorithm is then formulated corresponding to the given division of areas based on an alternating direction method of multipliers (ADMM) algorithm, which is greatly simplified by exploiting the structure of active distribution networks (ADNs). The problem is solved for each area with very little interchange of boundary information between neighboring areas. The standard ADMM algorithm is extended using a varying penalty parameter to improve convergence. The validity of the method is demonstrated via numerical simulations on an IEEE 33-node distribution network, a PG&E 69-node distribution system, and an extended 137-node system.
