A Coordinated Decentralized Loss Minimization Scheme for Hybrid AC/DC Distribution System with Multiple Microgrids

Loss minimization of distribution systems with hybrid AC and DC multi-microgrids is one of the main tasks in operation of active distribution systems. This paper presents a coordinated loss minimization scheme for distribution system including multiple AC/DC microgrids with high penetration of distributed energy resources (DERs). The coordination is conducted using a non-cooperative coordination framework in which the agents i.e. distribution system operator (DSO) and micro-grids managers (MGOs), selfishly minimize power losses of their sub-systems. However, they interact with each other to modify their solutions until an equilibrium is obtained in which each agent reach a satisfactory value for the power loss of its relevant network. The proposed scheme is modeled as a decentralized optimization problem which decomposes the whole problem into DSO and MGOs sub-problems which are coordinated through exchanging only boundary information. Thus, the computational and communicational burdens are reduced and data privacy of agents is preserved while matching all boundary variables. The exchanged boundary variables between DSO and each AC microgrid are active and reactive powers and voltage magnitude and angle whereas DC micro-grids exchange active power and voltage with DSO. The effectiveness and high computational performance of the proposed decentralized non-cooperative scheme is verified by various simulations on a modified 69-bus distribution system consisting of some AC and DC micro-grids.