Small signal stability analysis of renewable source connected power system and identification of oscillatory modes using wavelet transform

This paper analyzes the impact of integration of solar PV and wind power generation on small signal stability of the power system. Standard benchmark IEEE 09 bus system is used for study. The impact has been analyzed by replacing the conventional synchronous generator with solar photo-voltaic generation (SPVG) and doubly fed induction generator (DFIG) wind turbines separately. The effect of varying penetration level of solar and wind power is also investigated. Eigenvalue analysis is used to compute the frequency and damping factor of oscillatory components that arise due to small disturbances. The oscillatory modes are identified using discrete wavelet transform (DWT), a spectral analysis technique. Power spectral density and time frequency curves are used to extract hidden frequency information from the signal. The different cases have simulated in MATLAB based PSAT, wavelet, and time frequency signal analysis toolboxes.