Steady State And Dynamic Performance Analysis Of DFIG Using Maximum Power Point Tracking Strategy

Wind energy power generation has become the undoubtedly most prominent among all other renewable energy power generations due to cost-effectiveness,eco-friendly nature,and abundant availability.With the advancement in new wind technology,researchers have developed new methods and algorithms to control and make it an efficient and reliable source of energy.However,there are many problems associated with the integration of wind farms such as low inertia,altered frequency response,and reactive power control,fault current level,low voltage ride through(LVRT),etc.Low voltage ride through also known as voltage dip is one of the common phenomena that occur in power systems during the integration of wind farms.This study mainly divided into two parts.Firstly,steady state modeling and analysis of DFIG in a pitch-regulated variable speed wind turbine are presented by comprising two different magnetizing strategies using stator flux-oriented vector control technique.The steady state performance of DFIG is obtained by employing magnetization of stator and rotor.The simulation results show that the magnetization of DFIG through the stator requires a higher stator current and a smaller rotor current than that of rotor-based magnetization.Moreover,it is found that magnetization through stator implies better efficiency and lesser power loss as compared to the DFIG magnetized through rotor.Secondly,the dynamic performance of DFIG based wind turbine with maximum power point tracking strategy is investigated by voltage disturbance of different depth magnitude.It is well known that when an integrated wind farm connected with a conventional grid undergoes severe voltage disturbance then the high value of overcurrent and overvoltage tend to flow in rotor side converter circuit.If adequate solutions are not introduced then this type of severe disturbance not only damages the rotor side converter circuit but may also seriously threaten the stability of the concerned power system.In order to avoid such an unusual situation,a crowbar protection circuit at the output of the rotor side converter needs to be introduced that not only protects the rotor side converter circuit from overcurrent and overvoltage but also avoid losing system control under severe voltage disturbance.The corresponding simulation results under different severe voltage disturbance with crowbar protection are investigated.The simulation results show that under severe voltage disturbance the crowbar protection not only timely activate to prevent the rotor circuit but also avoids losing the synchronism of DFIG based wind turbine system from the grid enhancing system stability and reliability.