Power Propagation Characteristics from Wind Energy to Electricity Grids Considering Multi-Physical Impacts

Industry experience has shown that wind turbine (WT)-based energy systems are prone to causing oscillation problems in the electricity grid. One significant distinction between WT system and photovoltaic (PV) system is the property of their primary energy, the former is rotating and the latter is static. Hence, this paper develops a multi-physical model composed of aerodynamic, mechanical drive train, electrical, and control systems for DFIG-based wind energy system, to study the power propagation characteristics from wind energy to electricity grid, showing the impacts of the WT system on the grid. The theoretical analysis shows that the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3np$</tex> Hz distortion in wind energy can be propagated to AC grid within the bandwidth around 11 Hz, while it is attenuated at high frequencies. The results of PLECS-based simulation clearly validate the correctness of the theoretical analyses.