Modeling of photovoltaic generator as a random variable

Abstract:

The uncertainty introduced by non-dispatchable generation, e.g. photovoltaic, affects the daily operation and planning of electric networks. To study this uncertainty, it is common to model the performance of photovoltaic units from a pbkp_rediction of solar radiation. In this work a method to pbkp_redict this photovoltaic generation is proposed. The purpose of this pbkp_rediction is to obtain the output electrical power from the photovoltaic generator as a random variable. This random variable can be used in studies where it is considered appropriate to take into account the uncertainties, e.g. probabilistic load flow. The clearness index and the fraction of diffuse radiation, which are considered random variables, are the basis of the model proposed. An expression that gives the global radiation on a sloped surface is obtained, depending on the input variables that are the clearness index and the fraction of diffuse radiation. After that, another expression that gives the output electrical power from the photovoltaic generator, also as a function of the input random variables, is reached. Cumulants method is used to solve equation for output electrical power from a photovoltaic generator. To characterize the output random variable obtained, Gram-Charlier expansion is used. The model proposed in this work takes into account the random nature of solar radiation, dependent on the geographical location where the solar panels are installed, and the hour and day of the year in which the simulation is performing. This approach allows determining the output electrical power from a photovoltaic generator at any place and hour as random variable.

Año de publicación:

2014

Keywords:

Fuente:

scopus