Suppression of Sub-synchronous Oscillation in Direct-drive Permanent Magnet Wind Turbine Based on Generator-side Converter Compensation Control

Abstract

Large-scale permanent magnet direct-drive wind farms frequently experience sub-/super-synchronous oscillations in the case of weak power grids. However, most of the improved control strategies are based on grid-side converters (GSCs). Machine-side systems including machine-side converters (MSCs) and permanent magnet synchronous generators (PMSGs) are often simplified to current sources when analyzing control systems. In this paper, the small-signal model of the aircraft-side system under dq coordinates is analyzed. The disturbance path of the DC bus voltage to the machine-side system is found, and the corresponding compensation method is proposed to suppress the subsynchronous oscillation and improve the system stability. The simulation results verify the effectiveness of the proposed method.