Improvement of Low Voltage Ride-through Capability of DFIG-based Wind Turbines under Low Voltage Condition

The operating time modification for low voltage ride-through capability enhancement is modified the working time of the protective device according to low voltage ride-through (LVRT) characteristic. For this method, the protective equipment can keep the grid-connection between the distribution system and wind farm during the under low voltage condition. This research presents the voltage-time characteristic according to the LVRT characteristic, which was applied to the low voltage protection algorithm for wind turbines. This algorithm is proposed the tripping time with the prospective time on LVRT characteristic. This proposed algorithm is applied to the new protection scheme in wind turbine applications. The IEEE14 bus test system was selected to test the proposed algorithm in MATLAB environment. The simulation results showed that the low voltage protection algorithm could reduce the operating time according to the low voltage ride-through characteristic. This study can verify that this algorithm can apply to the other LVRT characteristic scheme by changing the particular equation.