Performance analysis of grid-connected wind turbines

The development of wind turbines (WT) and the capacities of wind power plants have increased significantly in the last years. Wind power plants (WPP) must provide the power quality required by new regulations and the reliability of the power system that is interconnected to. It is very important to analyze and understand the sources of disturbances that affect the power quality. In this paper is analyzed the performance of three different popular wind generators that are connected to the power system. Based on this analysis was made a comparison for the three wind turbines studied that are: The squirrel-cage induction generator (SCIG), the doubly-fed induction generator (DFIG), and the permanent-magnet synchronous generator (PMSG). The fixed speed system is more simple and reliable, but severely limits the energy production of a wind turbine and power quality. In case of variable speed systems, comparisons shows that generator of similar rating can significantly enhance energy capture as well as power quality. Moreover, performance of their output power leveling is validated by a new method numerically as maximum energy function and leveling function. The performances of these wind turbines and their characteristics are analysed in steady-state. Wind turbines systems are modeled in Matlab/Simulink environment. Simulation results matched well with the theoretical turbines operation.