“The modeling and computational requirements to represent in detail various system elements and conditions to properly study stability in Microgrids (MGs) could be very onerous, requiring certain computational tools that restrict the types of studies that can be performed, thus limiting dynamic simulations to a few seconds for a reduced number of MG components. Moreover, model approximations that reduce computational burden and may be able to efficiently represent certain dynamic phenomena in MGs, might not be sufficient to fully analyze the stability of these systems. Therefore, this document focuses on studying and determining the validity and types of applications of detailed and approximate component models for MG dynamic studies and simulations, in the context of the IEEE 1547 standard, in particular generator and grid modeling, full and average converter models, unbalanced and balanced system conditions, dynamic and static loads, and detailed and simplified controls considering communications delays, packet losses, and security issues. A discussion of the use of phasor vis-à-vis electromagnetic transient simulation tools for dynamic stability studies is also presented, together with the role that dynamic phasor and co-simulation approaches could play in such studies. Considering the future integration of grids and MGs to form broad integrated networks, modeling scale-up issues as well as MG equivalent models, specifically white-, grey-, and black-box models, are discussed in the context of dynamic stability analysis and simulations of such large systems. Finally, the modeling needs in MG protection are presented”--publisher’s website.

Microgrids Presents microgrid methodologies in modeling, stability, and control, supported by real-time simulations and experimental studies Microgrids: Dynamic Modeling, Stability and Control, provides comprehensive coverage of microgrid modeling, stability, and control, alongside new relevant perspectives and research outcomes, with vital information on several microgrid modeling methods, stability analysis methodologies and control synthesis approaches that are supported by real-time simulations and experimental studies for active learning in professionals and students alike. This book is divided into two parts: individual microgrids and interconnected microgrids. Both parts provide individual chapters on modeling, stability, and control, providing comprehensive information on the background, concepts, and architecture, supported by several examples and corresponding source codes/simulation files. Communication based control and cyber security of microgrids are addressed and new outcomes and advances in interconnected microgrids are discussed. Summarizing the outcome of more than 15 years of the authors’ teaching, research, and projects, Microgrids: Dynamic Modeling, Stability and Control covers specific sample topics such as: Microgrid dynamic modeling, covering microgrid components modeling, DC and AC microgrids modeling examples, reduced-order models, and model validation Microgrid stability analysis, covering stability analysis methods, islanded/grid connected/interconnected microgrid stability Microgrids control, covering hierarchical control structure, communication-based control, cyber-resilient control, advanced control theory applications, virtual inertia control and data-driven control Modeling, analysis of stability challenges, and emergency control of large-scale interconnected microgrids Synchronization stability of interconnected microgrids, covering control requirements of synchronous microgrids and inrush power analysis With comprehensive, complete, and accessible coverage of the subject, Microgrids: Dynamic Modeling, Stability and Control is the ideal reference for professionals (engineers, developers) and students working with power/smart grids, renewable energy, and power systems, to enable a more effective use of their microgrids or interconnected microgrids.

The stability of power systems and microgrids is compromised by the increasing penetration with power electronic devices, such as wind turbines, photovoltaics and batteries. A simulation and optimization environment for such low-inertia systems is created. It is investigated how accurate the models need to be to capture the prevailing modes. An evolutionary algorithm tailored to optimization problems with computationally intensive fitness evaluation is proposed in order to optimized the controller parameters of grid-forming and grid-supporting distributed generators. It becomes apparent that microgrids dominated by grid-forming inverters are very stable systems when well-designed and optimized controllers are used. Model simplifications, such as the neglect of inner control loops of inverters, must be examined carefully, as they can lead to an inaccurate stability assessment.

Microgrids: Modeling, Control, and Applications presents a systematic elaboration of different types of microgrids, with a particular focus on new trends and applications. The book includes sections on AC, DC and hybrid AC/DC microgrids and reflects state-of-the-art developments, covering theory, algorithms, simulations, error and uncertainty analysis, as well as novel applications of new control techniques. Offering a valuable resource for students and researchers working on the integration of renewable energy with existing grid and control of microgrids, this book combines recent advances and ongoing research into a single informative resource. The book highlights recent findings while also analyzing modelling and control, thus making it a solid reference for researchers as well as undergraduate and postgraduate students. - Covers different types of microgrids and their architecture and control in a single book - Includes original, state-of-the-art research contributions by international experts - Features global case studies for better understanding and real-life examples

Distributed generation systems (DGs) have been penetrating into our energy networks with the advancement in the renewable energy sources and energy storage elements. These systems can operate in synchronism with the utility grid referred to as the grid connected (GC) mode of operation, or work independently, referred to as the standalone (SA) mode of operation. There is a need to ensure continuous power flow during transition between GC and SA modes, referred to as the transition mode, in operating DGs. In this book, efficient and effective transition control algorithms are developed for DGs operating either independently or collectively with other units. Three techniques are proposed in this book to manage the proper transition operations. Modeling of the microgrid system and stability analysis has been presented in this book.

This work presents a unified method for dynamic modeling and stability analysis of microgrid power systems. Using the automated state-model generation algorithm, a state-space model of the microgrid power system is derived. The model may be used to conduct time-domain simulations and analyze system response to large transients. Additionally, eigenvalues of the system may be analyzed with respect to inverter control gains to assess small-signal stability. The proposed methodology is verified for large-signal transient study and small-signal stability analysis using dual and single-inverter microgrid systems, respectively. The presented method is general and may be applied to any three-phase circuit topology and inverter control without the need to derive circuit state equations.

This book intends to report the new results of the microgrid in stability analysis, flexible control and optimal operation. The oscillatory stability issue of DC microgrid is explored and further solved. Flexible and stable voltage & frequency control of microgrid is put forward considering the distributed generations or distributed energy storages. The optimal operation of multi-energy is researched in view of economic efficiency and low-carbon development. The results of this book are original from authors who carry out the related research together for a long time, which is a comprehensive summary for authors’ latest research results. The book is likely to be of interest to university researchers, electrical engineers and graduate students in power systems, power electronics, renewable energy and microgrid.

The concept of the microgrid is widely studied and explored in both academic and industrial societies. The microgrid is a power system with distributed generations and loads, which is intentionally planned and can be disconnected from the main utility grid. Nowadays, various distributed power generations (wind resource, photovoltaic resource, etc.) are emerging to be significant power sources of the microgrid.This thesis focuses on the system structure of Photovoltaics (PV)-dominated microgrid, precisely modeling and stability analysis of the specific system. The grid-connected mode microgrid is considered, and system control objectives are: PV panel is working at the maximum power point (MPP), the DC link voltage is regulated at a desired value, and the grid side current is also controlled in phase with grid voltage. To simulate the real circuits of the whole system with high fidelity instead of doing real experiments, PLECS software is applied to construct the detailed model in chapter 2. Meanwhile, a Simulink mathematical model of the microgrid system is developed in chapter 3 for faster simulation and energy management analysis. Simulation results of both the PLECS model and Simulink model are matched with the expectations. Next chapter talks about state space models of different power stages for stability analysis utilization. Finally, the large signal stability analysis of a grid-connected inverter, which is based on cascaded control of both DC link voltage and grid side current is discussed. The large signal stability analysis presented in this thesis is mainly focused on the impact of the inductor and capacitor capacity and the controller parameters on the DC link stability region. A dynamic model with the cascaded control logic is proposed. One Lyapunov large-signal stability analysis tool is applied to derive the domain of attraction, which is the asymptotic stability region. Results show that both the DC side capacitor and the inductor of grid side filter can significantly influence the stability region of the DC link voltage. PLECS simulation models developed for the microgrid system are applied to verify the stability regions estimated from the Lyapunov large signal analysis method.

The book focuses on the transient modelling, stability analysis and control of power electronic systems, since these systems face severe safe operation problems the during transient period. It discusses both theoretical analysis and practical applications, highlighting the transient characteristics of converters with different control strategies, and proposes transient modelling and model reduction methods. Furthermore, it classifies the transient stability problems of the system to help the readers gain an understanding of the basic theoretical methods for analysing the power electronic system, at the same time providing sufficient detail to enable engineers to design such systems. Comprehensively describing theoretical analyses, ranging from system modelling and stability analysis to transient control, the book is a valuable resource for researchers, engineers and graduate students in fields of transient modelling, stability analysis and control of power electronic systems.

This book introduces several novel contributions into the current literature. Firstly, given that microgrid topologies are paramount in theoretical analysis, the author has proposed a rigorous method of computing the network’s admittance matrix and developed to facilitate the stability analysis of DC microgrids supplying nonlinear loads. This unique approach enabled the factorisation of the admittance matrix in a particular way that facilitates a rigorous theoretical analysis for deriving the stability conditions. Secondly, author has proposed a unified control structure at the primary control layer that maintains the widely accepted droop-based approaches and additionally ensures crucial current- and voltage-limiting properties, thus offering an inherent protection to distributed energy resources. He has formalised the control design proofs using Lyapunov methods and nonlinear ultimate boundedness theory, for both parallel and meshed microgrid configurations. Moreover, he has developed a distributed secondary controller using a diffusive coupling communication network, on top of the primary control, to achieve voltage restoration and improve the power sharing. In this way, the author has formulated the complete hierarchical control scheme. In this high-order nonlinear setting, he has analytically proven closed-loop system stability of the overall system, for the first time, using two-time scale approaches and singular perturbation theory, by formulating rigorous theorems that introduce straightforward conditions that guide the system and control design and demonstrate system stability at the desired equilibrium point. In addition, the author has provided a straightforward algorithm for simple testing of system stability and explored from a graphical perspective by giving an interpretation to the effect of the nonlinear load onto the system performance and stability.