Improving Low Voltage Ride-through Capabilities for Grid Connected Wind Turbine Generator

Low Voltage Ride-Through (LVRT) is one of the most dominant grid connection requirements to be met by Wind Energy Conversion Systems (WECS). In presence of grid voltage dips, a mismatch is produced between the generated active power and the active power delivered to the grid. Low voltage ride through requirement demands management of this mismatch, which is a challenge for the WECS. In this paper, LVRT requirements provided by Wind Grid Codes have been reviewed. This paper discusses the standards for interconnection of wind generators to local grid during healthy and fault conditions. As per LVRT requirement, during dip occurrence, the wind power generation plant must remain connected to the grid and in addition, it has to deliver reactive power into the grid to aid the utility to hold the grid voltage. Voltage sag proves to be the most prominent power quality issue and the effect of voltage sag on different wind generator topologies has been investigated. Several methods for LVRT fulfillment have been explored and the LVRT scheme has been validated based on MATLAB-SIMULINK simulation.