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.

Variations of solar irradiance are known to have a significant influence on electric power generation by solar energy systems. With high connection densities of PV system in the low voltage (LV) network, this might cause to degrade electric power quality. The present study describes a multiplicative ARMA models to generate instantaneous series of global irradiation. The data set used in this work corresponding to five minutes global irradiance data were recorded in a radiometric station located in south Spain (Cordoba) during a for years period (1994-1997). The development of these models is based on removing the annual periodicity and seasonal variation of solar radiation. The method proposed considers fitting an AR model to the data. The selection of the order of the model has been made on the basis of seven different criteria. The predicted values of solar radiation are compared with the observed data series and it was found that this approach leads to optimal predictions.

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