Small Disturbance Stability Analysis of Weak-Grid-Connected DFIG-Based Wind Power System

Abstract

This paper is focused on the small disturbance stability of weak-grid-connected DFIG-based wind power systems. Firstly, the theory and structure of the system are expounded, and the complete mathematical model is deduced. Secondly, a reduced-order small signal model that disregards the mechanical component is created using the eigenvalue analysis approach as a foundation. The eigenvalues and correlation factors are then used to derive a categorical definition of the system oscillation modes. The eigenvalues and correlation factors are then used to derive a categorical definition of the system oscillation modes. Following that, based on the eigenvalue trajectory analysis, preliminary conclusions on the influence of the control parameters of the phase-locked loop (PLL), rotor-side converter (RSC), grid-side converter (GSC), and grid strength are obtained. Finally, the corresponding time-domain simulation model is created in MATLAB/Simulink. Finally, analyzing the active power waveform changes after disturbance confirms the correctness and accuracy of the theoretical conclusion.