Optimal Communication Network Design for Discrete-Time Distributed Secondary Control of Islanded Microgrid

Abstract

The communication network design significantly influences the control performance and stability of distributed secondary control in islanded microgrids (IMGs). Existing communication network design methods, rooted in continuous-time control theory, are ill-suited for IMG discrete-time control systems and may even result in instability. To address this disparity, we propose an optimal communication network design method for discrete-time distributed secondary control of IMGs, encompassing communication topology and weight design. Initially, discrete-time convergence conditions are derived and a novel convergence performance metric is introduced for distributed secondary control of IMGs. Subsequently, an optimal weight design for a specific communication topology is presented, achieved by solving a semi-definite programming (SDP) problem. To accelerate the solution of this SDP, we provide a method of selecting an appropriate initial value for iteration. A design approach for the optimal communication topology is then outlined, capable of identifying the communication topology with optimal performance under cost constraints. Simulation cases validate that the proposed communication network design yields superior control performance compared to the existing design.