A framework to assess voltage stability of power grids with high penetration of solar PV systems

In recent years, grid integration of solar photovoltaic (PV) systems has proliferated across many countries in order to reduce greenhouse gas emission and minimize energy cost. However, the intermittency inherent within PV generator may affect the grid voltage stability significantly. Therefore, it is imperative to consider the intermittent nature of solar PV power generation and uncertainties associated with load demand to gain a clear insight on power grid voltage stability with high PV penetration. In this Writing – original draft, a framework is presented for power grid voltage stability analysis considering uncertainties of PV power generation and load demand using Monte Carlo simulation. The expected values of voltage stability indices such as critical eigenvalue, line loss, reactive power margin and loading margin have been determined in the proposed framework and their probability distribution have been obtained for different times throughout a day. The proposed methodology has been verified by analysing voltage stability of the modified IEEE 14 bus test system with high penetration of PV energy sources and considering uncertainties associated with load demand. The results provide a holistic understanding on voltage stability of the test system with different penetration levels of PV energy sources into the power grid during contingency as well as normal operating conditions.