C. Rus

Two New Applications of Artificial Neural Networks: Estimation of Instantaneous Performance Ratio and of the Energy Produced by PV Generators

The growth of photovoltaic (PV) for electricity generation is one of the highest in the field of the renewable energies and this tendency is expected to continue in the next years. As an obvious consequence, an increasing number of new PV components and devices, mainly arrays and inverters, are coming into the PV market. The need for PV arrays and inverters to be characterized has then become a more and more important aspect. Due to the variable nature of the operating conditions in PV systems, the complete characterization of these elements is quite a difficult issue.

Videocasts applied to the teaching of power supplies

In this paper, we present some video podcasts which will be used as a complement for several subjects corresponding to the new Industrial Electronic engineering grade that is given at the University of Jaén High Technical College. The aim is to contribute to develop a new teaching culture, which implies innovation and methodological changes focused on practice, skills development and ICTs use, according to the European Space for Higher Education guidelines. It is intended to promote the student autonomous work and to help for the learning of some concepts related with regulated and switched power supplies. For this purpose, 19 videocasts (15 of theory, 2 of simulation and 2 of laboratory practice) have been developed, each one having its own right. We comment the importance of videocasts as a learning resource at the University, as well as the procedure and materials required for their development.

Calculation of direct normal irradiation from global horizontal irradiation

Concentrator Photovoltaic (CPV) systems only work with the Direct Normal Irradiance (DNI), so a knowledge of DNI data is required for the design and evaluation of these kinds of systems. DNI is not always measured at ground meteorological stations due to equipment costs. In recent years, several spatial databases that estimate DNI from satellite data have been developed. These databases are a very useful tool for CPV applications. However, the databases present uncertainty and provide different values of DNI. This lack of DNI data and the uncertainty of available data contrast with the availability of reliable global horizontal irradiation data, which is easy to find or measure. In this paper, a simple procedure for estimating DNI from global horizontal irradiation is presented. It does not try to improve the existing methods, but meets the basic requirements for the analysis of CPV systems. The method can be easily implemented in a spreadsheet or in computer programs in renewable energy and its accuracy ...