Characteristics and Simulations of Sub-/Super-Synchronous Oscillations in Wind Farm Integrated System

The new power system shows “double-high” characteristics, leading to more complex problems such as multi-time scale interweaving, uncertainty, time-varying, and nonlinearity in the system, and the novel sub synchronous and supersynchronous oscillations with complex and variable dynamic characteristics have emerged, seriously threatening the electricity system's steady and secure operation, while also restricting the transmission and consumption of new energy. Therefore, it is essential to strengthen the cognitions of the novel sub synchronous and supersynchronous oscillation characteristics and conduct real-time monitoring to guarantee the secure functioning of the power grid. For this purpose, the new sub synchronous and supersynchronous oscillations in the wind power grid-connected system were classified and modeled, and their characteristics were analyzed and summarized in this paper. Firstly, the mechanisms and actual cases of subsynchronous and supersynchronous oscillations in the wind power grid-connected system were classified and expounded. Then, the simulation models of typical scenarios were built on PSCAD/EMTD, and the oscillation characteristics under different scenarios were analyzed. Finally, the characteristics of oscillations in wind farm integrated systems were summarized, and the challenges faced by existing oscillation analysis methods, suppression measures, and monitoring methods were pointed out, which can provide a reference for further research.