This document is a summary of a report prepared by the IEEE PES Task Force (TF) on Microgrid Stability Definitions, Analysis, and Modeling \cite{task}, which defines concepts and identifies relevant issues related to stability in microgrids. In this paper, definitions and classification of microgrid stability are presented and discussed, considering pertinent microgrid features such as voltage-frequency dependency, unbalancing, low inertia, and generation intermittency. A few examples are also presented, highlighting some of the stability classes defined in the paper. Further examples, along with discussions on microgrid components modeling and stability analysis tools can be found in the TF report.

In the context of microgrid, renewable energy variations are still a major concern for operators, especially in industrial applications in which microgrids are typically located in remote areas and are operated autonomously. Information gap decision theory (IGDT) is a nonprobabilistic method utilized to appraise various levels of risk without the availability of statistical data, such as probability density functions of uncertain parameters. Despite such a rewarding feature, the IGDT in its current form is unable to obtain time-varying robustness bands, meaning that it does not take into consideration the system risk imposed by renewable energy injections at each individual time interval in a short-term operation horizon. To overcome this issue, this article presents a modified version of the IGDT named weighted IGDT (W-IGDT), yielding risk-based time-varying robustness bands rather than time-independent ones. This article also proposes a W-IGDT-based energy management system (EMS) based on a linked unit commitment-optimal power flow (UC-OPF) framework, which simultaneously incorporates the generating units on/off status as well as power flow limits into the optimization procedure. In order to illustrate the performance of the proposed EMS, a CIGRE microgrid benchmark is utilized, and the results indicate the effectiveness of the W-IGDT-based EMS in terms of optimal operation and addressing the intermittency of renewable energy sources.

This article presents a test facility for design validation of microgrids with high penetration of renewable energy, developed as a joint effort with industry, government, and academia. The Canadian Renewable Energy Laboratory (CANREL) described here is a physical simulation tool for the design, development, and performance testing of islanded and grid-connected microgrid projects. CANREL is equipped with a diesel generator, different renewable energy sources, various renewable energy generation simulators and physical systems, a bidirectional power-flow grid simulator, a battery- based energy-storage system, and controllable resistive?inductive?capacitive and electronic test loads for the design and testing of a variety of microgrid solutions. The test facility provides project performance demonstration and validation services at each stage of a microgrid project development to help utilities and project developers reduce risks. It is also a physical simulation tool for benchmarking microgrid equipment and controllers for research and development purposes. Some facility test results are presented in this article to demonstrate the capabilities of CANREL for simulating a wide range of scenarios.