This paper presents a stochastic framework for the optimization of microgrids that has the functionality of providing flexibility services to System Operators (SOs) considering uncertainties in the energy forecast. The methodology is developed with the aim of being applied to complex microgrids composed of different distributed energy resources and hybrid energy storage systems (ESS). The associated optimization problem is operated in two stages: the first one performs a stochastic optimization of the microgrid in order to reserve an up/down regulation capacity with which to deal with the energy forecast uncertainties of the microgrid. The different microgrid devices are optimized by considering their operational costs in order to achieve their optimal operation in the Day-Ahead Market (DM). The second stage is used to re-schedule the initial planning according to the signal request and an economic offer from the SO. The control problem is developed using Stochastic Model Predictive Control (SMPC) techniques and Mixed-Integer Quadratic Programming (MIQP), owing to the presence of logic, integer, mixed and probabilistic variables. The simulation results show that the proposed methodology reduces the risk of undergoing up/down-penalty deviations in the Regulation Service Market (RM), also being able to provide flexibility services to the SOs, despite being subject to uncertainties in the energy forecast carried out for the microgrid.

There is, at present, considerable interest in the storage and dispatchability of photovoltaic (PV) energy, together with the need to manage power flows in real-time. This paper presents a new system, PV-on time, which has been developed to supervise the operating mode of a Grid-Connected Utility-Scale PV Power Plant in order to ensure the reliability and continuity of its supply. This system presents an architecture of acquisition devices, including wireless sensors distributed around the plant, which measure the required information. It is also equipped with a high-precision protocol for synchronizing all data acquisition equipment, something that is necessary for correctly establishing relationships among events in the plant. Moreover, a system for monitoring and supervising all of the distributed devices, as well as for the real-time treatment of all the registered information, is presented. Performances were analyzed in a 400 kW transformation center belonging to a 6.1 MW Utility-Scale PV Power Plant. In addition to monitoring the performance of all of the PV plant’s components and detecting any failures or deviations in production, this system enables users to control the power quality of the signal injected and the influence of the installation on the distribution grid.

Present distribution networks have not been designed to accept extensive Distributed Generation (DG). The present framework may change in the near future impelled by a worldwide increase in DG penetration in distribution grids. The mutual dependency of energy distribution and communications on the same grid requires new means for effectively monitoring and controlling both systems in parallel. Relaying and control IEDs can also serve as measurement units for power quality. Synchronized Measurement Technology (SMT) has the potential of becoming the backbone of this paradigm. By using wide-area information systems, the data can be made available to all involved partners. This paper provides different outlooks about the possibilities of Embedded Systems to integrate the protection, control and monitoring functions in Distribution Automation Systems. To justify the choice of synchronization technology, we have scheduled a complete sequence of synchronism tests and measurement tests based on standard specifications.

Resumen: Las transformaciones que están teniendo lugar en el sector eléctrico están haciendo evolucionar la red hacia un modelo más inteligente y eficiente conocido como Smart Grid. En este contexto, a los DERs que se integren en la red se les requerirá un control avanzado de la interfaz de conexión. Este trabajo presenta un original dispositivo electrónico inteligente (IED) de altas prestaciones para el control de la interconexión eléctrica con numerosas y nuevas prestaciones. El dispositivo tiene sobrada capacidad para contemplar tanto la calidad de suministro como operar multifuncionalmente a nivel de protección y seguridad; y su arquitectura modular en un Sistema Embebido permite una fácil integración, tanto en el desarrollo de equipos de nueva generación, como en equipamiento convencional ya instalado para adaptarlo al nuevo contexto de gestión inteligente. Se ha desarrollado un IED que ha sido sometido a pruebas de clase A siguiendo la normativa IEC 61000-4-30 e IEC 62586-2, y se le han efectuado ensayos para validar la respuesta temporal en la generación de órdenes y señales de alarma para protecciones. Se muestran y analizan algunos de estos resultados experimentales, y se comenta la experiencia de integración real de este prototipo en un inversor inteligente experimental, diseñado expresamente para operar en un escenario Smart Grid. The changes that are taking place in the electricity sector are causing an evolution of grid towards a more intelligent and efficient model known as Smart Grid. In this context equipment that connect to electric system require an intelligent control of the connection interface. This paper presents the design and development of an intelligent electronic device (IED) with high performance for controlling the electrical interconnection. The device has multifunctional ability to analyze power quality and operate with protections, and its modular architecture allows easy integration in both the development of next generation equipment, as in conventional equipment already installed to adapt to the new context of intelligent management. It has developed a prototype that has been tested with A class tests following the standards IEC 61000-4-30 and IEC 62586-2, and we have performed tests to validate the time response in generating orders and alarm signals for protections. Are shown and discussed some of these experimental results and the experience of integration of this prototype in an experimental smart inverter that is designed to operate in a Smart Grid scenario. Palabras clave: Redes inteligentes (smart grids), sistemas eléctricos y electrónicos de potencia, inversores, sistemas embebidos o empotrados, sistemas de tiempo real, monitorización y supervisión, energías renovables, Keywords: Smart grid, intelligent electronic device, distributed energy resource, embedded system, real time, monitoring and supervision, renewable energ