Impact of Solar Photovoltaic Integration on Transmission System based on Voltage Stability Index (VSI)

The integration of solar PVs which is projected to increase over the years creates concerns over stability. The high number of solar photovoltaic (PV) installations would cause voltage instability depending on the placement of PV. Reverse power flow usually happens within different voltage levels in the distribution system, but with higher penetration of PV injection, it may reach to transmission level. This paper concentrates on the impact of integration of a large number of household PVs on the transmission system with reference to Voltage Stability Index (VSI). The IEEE 30 bus test system is used to simulate the effect of PV integration at the transmission level from various penetration levels of solar PV.