Impact of increased penetration of large-scale PV generation on short-term stability of power systems

This paper investigates the impact of increased penetration of large-scale photovoltaic (PV) generation on the short-term stability of the IEEE New England 39-bus test system, considering the stochastic nature of power systems. Based on the probabilistic models of input parameters, such as load variation and the occurrence of contingencies, Monte Carlo-type simulations are performed to iteratively evaluate the system time domain response. Also, different strategies for voltage regulation capabilities for PV systems were analyzed. The simulation results identified both, improvement and detrimental effects on short-term stability with different penetration levels of PV generation. The beneficial or detrimental effects depend on the PV systems operating mode, whether or not including voltage regulation. Greater instability conditions are reported if Full Replacing (FR) of Conventional Generating Units (CGUs) is considered. However, fewer instability conditions are obtained if Partial Replacing (PR) is considered in lieu of FR since CGU keep excitation control systems (AVR, exciter) and turbine governor controls activated.