Evaluation of voltage dip characteristics in autonomous island networks and correlation with wind turbine FRT curves

Voltage dips constitute a major concern in networks with high distributed generation (DG) penetration, since they may provoke the simultaneous disconnection of large amounts of generation. Therefore, wind turbines (WTs) connected to these systems should present enhanced immunity characteristics against such disturbances. In this paper, an evaluation is performed of the expected voltage dip characteristics (magnitude-duration) in autonomous island networks, based on the settings of the line over-current protection devices. The expected dips are then correlated with common WT fault ride-through (FRT) curves to determine the suitability of commercially available machines for islands or other weak grids of similar type.