Renewable Energy Integration for Enhanced Power System Stability Under Large Disturbances

Abstract

The Large-Scale integration of renewable energy sources fundamentally alters the dynamic behavior of modern power systems, presenting both critical challenges and unprecedented opportunities for stability enhancement. This paper investigates the dual-edged impact of wind power, via Doubly-Fed Induction Generators, and solar photovoltaic systems on power system stability during severe contingencies. While the inherent intermittency of these sources characterized by fluctuating wind speeds and partial shading of PV arrays introduces significant operational uncertainties, their advanced power electronic interfaces offer a pathway for intelligent grid support. This work proposes a novel control framework that leverages the fast-acting reactive power capability of DFIGs and the active power modulation of solar PV inverters to provide synthetic inertia and voltage support, thereby improving the system's transient stability. Concurrently, a small-signal stability analysis is conducted using eigenvalue and modal decomposition techniques to evaluate the impact of these RESs on the system's damping characteristics and oscillatory modes. The efficacy of the proposed strategy is validated through time-domain simulations on a modified IEEE test system. Results demonstrate a marked improvement in rotor angle stability and critical fault clearing time, alongside enhanced damping of inter-area oscillations. This research establishes that, when equipped with suitable grid-forming controls, renewable energy sources are not merely a source of instability but a crucial asset for bolstering overall grid resilience against large disturbances.