Improving Wind Turbines Protection by Shifting Pickup Current of Overcurrent Relay in Distribution Network

Wind turbines have some effects on short circuitcurrent, which change the traditional protection schemes ofdistribution networks. One of these effects is reducing shortcircuit current of wind turbines in a short period of time afterfaults, as fault current magnitude comes below the pickupcurrent of overcurrent protection. In this paper, the mentionedproblem is investigated for different fault types. In addition, anew protection scheme, based on shifting the pickup current isproposed. The main idea of this new method is based upondecreasing the pickup current with respect to the voltage decline.To validate the proposed method a wind turbine connected to adistribution network is studied in MATLAB environment, andthe obtained results show that the new method has a good abilityfor fault detection and clearance.