Distributed and Asynchronous Active Fault Management for Networked Microgrids

A distributed and asynchronous active fault management (DA-AFM) method is developed to manage networked microgrids' (NMs) performance under balanced or unbalanced grid faults. The DA-AFM aims to (1) enable NMs' fast fault ride-through capabilities, (2) limit the total fault contributions by coordinating heterogeneous microgrids in the NM system, and (3) deploy software-defined networks (SDN) to ensure highly resilient AFM. The problem is formulated in an optimization form that can incorporate various fault management objectives and constraints in a programmable and flexible fashion. The scalability and resiliency of the DA-AFM system are guaranteed by adopting an SDN-enabled distributed and asynchronous surrogate Lagrangian relaxation (DA-SLR) algorithm, which avoids single point of failure, preserves privacy, and eliminates the idle waiting of other subproblems. Case studies are performed on a six-microgrid NM system to validate the effectiveness and efficacy of DA-AFM. Testing results show that DA-AFM has excellent convergence performance, supports plug-and-play, is resilient to communication delay and failures, meets real-time requirements and is scalable.