Influences of power electronic converters on current-voltage behaviors during faults in DGUs-Part I: Wind energy conversion systems

The growing interests in clean and sustainable electric energy push towards increasing the interconnection of wind energy conversion systems (WECS) to utility grids. Designs of the majority of WECSs employ power electronic converters (PECs), which generally have non-linear and switched characteristics. The characteristics, operation, and control of PECs in WECSs can result in non-conventional current-voltage behaviors during faults. This paper investigates the current-voltage behaviors during faults that occur in WECSs or their host grids. Two types of WECSs are considered in this paper, which are the doubly-fed induction generators (DFIGs) and permanent magnet generator (PMGs) based WECSs. The current-voltage behaviors are investigated in experimentations for different faults occurring during the grid-connected operation.