Determination of Maximum Power in Spread Photovoltaic  Parks to avoid Transient Stability Problems

Instituto de Energía Eléctrica, Universidad Nacional de San Juan, Argentina 

Abstract: Nowadays there is a trend to use Photovoltaic Generation to replace the conventional one which involves fossil fuels. This obliges to carry out studies to analyze different aspects of the operation of these parks where both technologies either conventional or nonconventional ones coexists. One of the aspects to be studied is the analysis of the electric system dynamic behavior called Analysis of Transient Stability. Photovoltaic generation systems, in contrast with conventional ones, are static, i.e. they do not have mobile parts, and nevertheless, changes in solar radiation produced by the presence of low and isolated clouds, modify the power delivered by the photovoltaic park. These changes of active power generated by photovoltaic parks are seen as a constraint by the electric system producing frequency variations in the electric system and the consequent speed variation in conventional generators in operation. Therefore, the impact of solar radiation changes under the presence of traveling trains of clouds over the Transient Stability,considering not only concentrated but also disperse Photovoltaic Generation, is analyzed in this work. At the same time, it is presented a methodology to determine a Penetration Index of Disperse Photovoltaic Generation which allows the definition of the maximum power coming from photovoltaic generation in relation to the maximum power demanded as well as the Spinning Reserve Power that guarantee the Transient Stability of the Power System, taking into account the geographical distribution of photovoltaic generators.