Impacts of solar PV generators on power system stability and voltage performance

Solar PV (Photovoltaic) generators can be connected to a transmission system as a large scale installation or distributed across a distribution system close to load. Both types of solar PV projects utilize full converter model to connect to the grid, but may have different reactive power capabilities. The voltage and reactive power response of solar PV generators under both normal and outage conditions hence may be different. The voltage level to which the solar PV generators interconnect is another factor that may cause the difference. Extensive studies have been performed at California ISO (CAISO) to assess different types of solar PV generator interconnections. Several important transient stability and voltage phenomena related to solar PV generator interconnections are presented and analyzed in this paper. Practical solutions to mitigate identified voltage impacts of solar PV are discussed.