The Impact of Increased Penetration of Solar Photovoltaic Generation on Rotor Angle Small Signal Stability of Power System

Conventional generators are gradually replaced by Renewable Energy Sources (RESs). The main incentive factors in this process are environmental concerns and cost reduction as well as technological advances in RESs that enable them to compete with conventional sources. Photovoltaic (PV) systems are one of the main choices for many operators among RESs. PVs have no inertia and are connected to grid through power electronic devices, therefore it is expected that different aspects of power system stability will be affected, particularly when the penetration is high. In this study, the impact of PV integration on rotor angle small signal stability is investigated. Power System Stabilizers (PSSs) as one of the effective devices in damping Low Frequency Oscillations (LFOs) are employed to damp out both local and inter-area modes of oscillations. Both AVRs and PSSs parameters are tuned simultaneously by comparing different multi-objective Optimization Algorithms (OAs). Study results in IEEE-39 bus New England test system confirm that optimal tuning of PSSs and AVRs can effectively improve damping of LFOs in cases with high PV penetration. Simulations are performed by interfacing Matlab (MathWorks) and DIgSILENT (PowerFactory). Obtained optimization results are applied for further analysis by calculating risk of small signal instability using a Monte Carlo-based probabilistic method.