Comparison between different methods of islanding detection for photovoltaic symmetric systems

This paper shows an analysis of the methodologies used to detect the islanding operating of the three-phase grid connected photovoltaic inverters. In some countries, the operating regulation before islanding conditions is not specified enough. Now the new operating procedures try to integrate the guidelines which the distributed generating systems must follow in order to reach an optimum operation under islanding conditions. Nevertheless, there is still a lack of regulation in this sense. In order to analyze the different detection methods, some simulations have been carried out. This document pretends to establish a test guideline, necessary to validate the islanding detection systems which are integrated inside the photovoltaic inverters, in order to ensure a correct operation of them. That is why the results of real tests of JEMA´s photovoltaic inverters have been included.