Abstract
The smart grid initiative, integrating advanced sensing technologies, intelligent control methods, and bi-directional communications into the contemporary electricity grid, offers excellent opportunities for energy efficiency improvements and better integration of distributed generation, coexisting with centralized generation units within an active network. A large share of the installed capacity for recent renewable energy sources already comprises insular electricity grids, since the latter are preferable due to their high potential for renewables. However, the increasing share of renewables in the power generation mix of insular power systems presents a significant challenge to efficient management of the insular distribution networks, mainly due to the variability and uncertainty of renewable generation. More than other electricity grids, insular electricity grids require the incorporation of sustainable resources and the maximization of the integration of local resources, as well as specific solutions to cope with the inherent characteristics of renewable generation. Insular power systems need a new generation of methodologies and tools to face the new paradigm of large-scale renewable integration. Smart and Sustainable Power Systems: Operations, Planning, and Economics of Insular Electricity Grids discusses the modeling, simulation, and optimization of insular power systems to address the effects of large-scale integration of renewables and demand-side management. This practical book: • Describes insular power systems, renewable energies, uncertainty, variability, reserves, and demand response • Examines state-of-the-art forecasting techniques, power flow calculations, and scheduling models • Covers probabilistic and stochastic approaches, scenario generation, and short-term operation • Includes comprehensive testing and validation of the mathematical models using real-world data • Explores electric price signals, competitive operation of distribution networks, and network expansion planning Smart and Sustainable Power Systems: Operations, Planning, and Economics of Insular Electricity Grids provides a valuable resource for the design of efficient methodologies, tools, and solutions for the development of a truly sustainable and smart grid. © 2015 by Taylor & Francis Group, LLC.

Abstract
Renewable energies are in constant growth and evolution, being a clean way to provide the energy required for the sustainable development of human society. In this context, energy storage systems are a key factor in the integration of renewable generation, because through them, the flexibility of the power system can be increased. Lead-acid batteries have been extensively used to provide electricity in isolated and rural locations, and could be integrated to the smart grid in order to improve its performance. However, this is a complex element due to its working principle, specifically during charging periods. In this paper, a general purpose model is formulated from a probabilistic point-of-view in order to determine the range of possible values of state-of-charge due to the uncertainty and to estimate the battery efficiency. A case study is analyzed and the results are compared with Monte Carlo Simulation approach in order to evaluate the proposed model. © 2016 IEEE.

Abstract
Recent research works have demonstrated that providing ancillary services for future microgrids is a challenging task due to the lack of sufficient spinning reserves and high cost of storage devices. Therefore, an increasing attention has been given to demand response (DR) as an emerging source to provide the required reserve, especially in emergency operation of the system. This paper proposes a decentralized multi-agent based DR strategy to control the domestic demands during the emergency operation of the microgrid (MG). According to the proposed multi-agent based DR strategy, the domestic loads are grouped based on a predefined priority and are assigned to specific load agents. To implement the information sharing process among the load agents, the consensus strategy is used. Communications among the load agents as a challenging issue of multi-agent systems (MAS) is considered and the effect of communication time delay is investigated. Simulation studies have been carried out on the CIGRE benchmark microgrid with various microsources and domestic loads, showing the effectiveness of the proposed decentralized control scheme.

Abstract
A control technique is proposed in this paper for control of modular multilevel converters (MMC) in highvoltage direct current (HVDC) transmission systems. Six independent dynamical state variables are considered in the proposed control technique, including two ac currents, three circulating currents, and the dc-link voltage, for effectively attaining the switching state functions of MMCs, as well as for an accurate control of the circulating currents. Several analytical expressions are derived based on the reference values of the state variables for obtaining the MMC switching functions under steady state operating conditions. In addition, dynamic parts of the switching functions are accomplished by the direct Lyapunov method to guarantee stable operation of the proposed technique for control of MMCs in HVDC systems. Moreover, the capability curve of MMC is developed to validate maximum power injection from MMCs into the power grid and/ or loads. The impacts of the variations of MMC output and dc-link currents on the stability of dc-link voltage are also evaluated in detail by small-signal analysis.

Abstract

Abstract
Developments of the smart grid infrastructure can facilitate the upsurge of Demand Response (DR) share in power system resources. This paper models the effects of Demand Response Programs (DRPs) on the behavior of the electricity market in the Day-Ahead (DA) session. Decision makers look for the best DR tariff to employ it as a tool to obtain a flexible and sustainable energy market. Employing the most effective DRP is of crucial importance. An optimized DR model and the optimum rates for each DRP are found to meet the decision makers' requirements. Optimizing the nodal tariff and incentive values of different DRPs are proposed in the electricity market. In such environment, market interactions are considered by means of a security constrained unit commitment problem. Both types of Price-Based Demand Response (PBDR) and Incentive-Based Demand Response (IBDR) are modeled. The numerical results presented indicate the effectiveness of the proposed model.