This paper presents modeling and analysis of electrical oscillations in a wind farm system. The detailed modeling and modal analysis of a wind farm system are presented in this paper. The approach to modeling uses detailed representation of a wind turbine generator and collection system including high-voltage direct-current (HVDC) power converter system control, facilitating a comprehensive analysis of the wind farm system. Various modes are classified according to the frequency of oscillation. The detailed modal analysis is used to characterize the critical modes. Time-domain simulation also confirms the presence of these modes. The effect of wind farm operating conditions and voltage source converter control tuning on critical oscillatory modes are also assessed and discussed in detail.