Characterization of wind and solar generation and their influence on distribution network performances

The paper is aimed at focusing the influence and more in general benefits and problems that medium size wind turbines, photovoltaic power plants, and small cogenerative generators embedded in a radial distribution network can produce regarding voltage profiles and power balance. In particular the novel capability of wind turbines to reduce active power in case of over-frequency is analyzed. This feature in fact is found to be quite important in reducing frequency deviation in case of high penetration of wind turbines during severe islanding conditions. The production profiles of each generator are detailed in function of their variability. So wind turbine outputs are detailed with a time scale of 15 minutes while combustion engine outputs every 60 minutes. The possibility of congestions or voltage peaks is studied by steady state simulations, performed by a widely used power system analysis code, in a temporal window of ten days. Different simulations scenario are analyzed with the presence or less of embedded generation and with as well as without the capability of generator to regulate reactive power.