ROTOR ANGLE DYNAMICS ASSESSMENT IN A LOW INERTIA GRID: WAVELET BASED APPROACH

摘要

Future power systems are forecasted that they will mainly be comprised of renewable energy sources. However, integration of these renewable energy sources into the grid brings additional stability challenges because of the reduced system inertia. The magnitude of inertia has an impact on the competency of the system to harmonize. The available synchronous generator rotor angle is one of the inertial variables, which affects transient stability. Low inertia results in higher rate of change of angle during a fault. Most rotor angle stability studies are based on centralized penetration and one type of load model. Rotor angle stability in the low inertia grid for different integration strategies, under different load models is observed in this study. Observation of the impact of load models on rotor angle stability is particularly important because these load models have notable effects on the way the independent generators speed up or slow down when the system is subjected to a fault. The study is observed in PowerWorld using standard IEEE 9-bus test system and the signals are analyzed in Matlab using the wavelet analyzer toolbox. Simulation results are given to show the impact of load models and integration strategies.