An electromechanical emulation-based study on the behaviour of wind energy conversion systems during short circuit faults

•An emulator is developed to study the behavior of wind turbines during grid faults.•Effects of grid faults on the electrical parts of WT are investigated by the emulator.•Effects of grid faults on the blade and tower of WT are studied by the emulator.•Simulation studies are done to evaluate the performance of WT during grid faults. Short circuit faults are important phenomena and they may have severe effects on the power system components such as wind turbines (WTs). Although variable-speed WTs are taking the major share of new wind power installation, fixed-speed WTs are still a significant part of the existing wind power plants. Therefore, performance evaluation of these WTs during faults is a vital issue from the viewpoint of system stability, protection, and lifetime. In this paper, the effects of short circuit faults on the electrical and mechanical parts of fixed-speed WTs are investigated in simulation and in emulation using a new emulator. A comprehensive model of the WT that considers the aerodynamic, mechanical, and electromechanical interactions between the power system and the WT is used in the simulation and emulation studies. Results showed that short circuit faults not only have severe effects on the electrical parts of the WTs, but also they can generate vibrations on the mechanical parts such as blades and tower that can reduce their lifetime. Results show that how the fault type, its duration, voltage drop level, and grid strength can affect the system performance. Since the developed emulator considers all main aspects of a WT and their interactions, it can be used as a tool to develop more economical and better performing WT.