Power Propagation Characteristics From Wind to Electric Grid for PMSG-Based Wind Turbine

The mechanical power absorbed by wind turbine (WT) from wind power exhibits periodic fluctuations due to the aerodynamic characteristics. The fluctuations are propagated to the power grid through the WT system, which is composed of drive train, generator, back-to-back converter and control system. Hence, in this paper, a multi-physical model of permanent magnet synchronous generator (PMSG)-based WT is derived. The model, which includes the detailed mechanical and electrical systems, can quantitatively analyze the power propagation characteristics, and thus study the impacts of the control strategy. The model is validated by PLECS and OPAL-RT 5707-based simulation platform. The theoretical analyses and validation results clearly show that the low-frequency 3np fluctuations can be propagated to the grid, causing sub-synchronous oscillations issues.