Multilayer event‐based distributed control system for DC microgrids with non‐uniform delays and directional communication

Abstract

The secondary control layer of microgrids is often modelled as a multi-agent distributed system, coordinated based on consensus protocols. Convergence time of consensus algorithm significantly affects transient stability of microgrids, due to changes in communication topology, switching of distributed generations (DGs), and uncertainty of intermittent energy sources. To minimise convergence time in consensus protocol, this work proposes a multilayer event-based consensus control framework, which is resilient to communication delays and supports plug-and-play (P&P) addition or removal of DGs in DC microgrids of cellular energy systems. A novel bi-layer optimisation algorithm minimises convergence time by selecting an optimal communication topology graph and then adjusts controllers' parameters. Average consensus is achieved among distributed controllers using an eventbased consensus protocol, considering non-uniform delays between agents. A realisation method has also been introduced using the directional beamforming technique for topology assignment algorithm based on modern telecommunication technologies. Provided feasibility case study has been implemented on a real-time hardware-in-the-loop (HIL) experimental testbed, to validate the performance of the proposed framework for key purposes of voltage stabilisation and balanced power-sharing in DC microgrids. INTRODUCTIONFor a distributed microgrid with renewable energy sources (RES) and energy storage systems (ESSs), distributed control architecture is a natural choice compared to current centralised supervisory control and data acquisition (SCADA)-based approaches. The main advantages of distributed controllers are (1) increased reliability against controller failures, (2) distribution of computational complexity, and (3) robustness in the control system [1]. In microgrids, distributed control and estimation are mainly implemented in secondary and tertiary layers, due to distributed nature of RES, and limitations of the communication network. Optimal neighbour data sharing and multi-agent consensus protocols are problems of interest in proposed distributed strategies [1,2]. Among available consensus protocols in multi-agent systems, distributed average consensusThis is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

A novel distributed privacy‐preserving control and data collection method for IoT‐centric microgrids

“…A real-time model of a 380 V DC microgrid is simulated in MATLAB/Simulink to show the effectiveness of the proposed strategy based on our previous work in [25]. The communication topology changes during the operation of the DC microgrid either due to DG getting online/offline or due to the isolation scheme after malicious activity detection.…”