Modeling and performance analysis of large solar photo-voltaic generation on voltage stability and inter-area oscillations

The behavior of Solar Photo-Voltaic Generation (SPVG) in the grid is defined by the way its output active and reactive power are controlled; the reactive power can be controlled directly as a preset value or indirectly through controlling the voltage magnitude at the point of common coupling (PCC). Therefore, two basic modeling approaches are considered in the present work: constant reactive power and constant voltage magnitude models, for an infinite-capacitor SPVG. Based on these models, studies of the effect on the system´s voltage and angle stability of integrating SPVG into the grid are presented and discussed for the IEEE 14-bus benchmark system. The analyses are performed at the transmission system level and from the system operator´s perspective. Therefore, voltage stability studies are carried out using PV curves, small-perturbation stability studies are performed based on eigenvalue analyses of the linearized system modes, and time domain studies are carried out to examine the overall performance of the system in the case of contingencies. From the results and studies presented, it is shown that SPVG in PV-control mode does not negatively affect the stability of the system, and it may actually improve it.