This document discusses the structural analysis of a wound rotor shaft for a 2.1 MW wind turbine operating at various speeds and frequencies. It analyzes a single-piece steel rotor shaft and models its geometry and meshing. It then presents the results of the total deformation, maximum stress, and maximum strain on the shaft material from simulations run at rated speed, over speed, and critical speed for frequencies of 50Hz and 60Hz. The analysis shows the steel material is capable of withstanding the stresses and strains from operating at various speeds and frequencies for the wind turbine application.