Voltage support in industrial distribution systems in presence of induction generator-based wind turbines and large motors

Industrial loads are usually composed of large induction motors (IM). These motors present a critical behavior under some circumstances, e.g. during starting and faults in the system. Currently, induction generator-based wind turbines are also connected to distribution systems. Essentially, these generators present the same behavior of large IM and, when directly connected to the system, their interaction can increase voltage sag levels or even lead the system to a voltage collapse. These generators, however, are usually provided with specific controls or power electronic-based equipment to comply with the voltage ride-through capability required by the grid codes. These resources, however, can be used to minimize the impact of large motors in the grid or even minimize their impact on voltage sags caused by faults in the system. In this context, this paper has the objective of analyzing the impact of different technologies used in induction generator-based wind turbines during disturbances in distribution systems in the presence of large IM. The analysis aims to clarify the potential benefit of wind turbine allocation at the demand side of an industrial power distribution system. Based on the results, an adapted control scheme, considering the control strategies currently available, is proposed for the grid side converter of the doubly fed induction generators to improve power quality.