Research On Influence Of Key Components On LVRT Characteristics Of DFIG Wind Turbine

Currently, Low voltage ride through (LVRT) field test is the main method to assess LVRT capability of wind turbine. Generally, same type and same capacity wind turbines take different lengths of blades, generators and pitch systems. If a wind turbine has completed LVRT test, whether the wind turbines which replace the other blade length or other types of generators still need to be tested again is a problem for wind turbine manufactures and testing organizations. In this paper, the influence of key components such as blade, generator and pitch system replacement on LVRT capacity of double fed induction generator (DFIG) wind turbine are studied. The main research contents are as follows:(1) The DFIG wind turbine co-simulation model is built with Bladed and Matlab/Simulink. Communication and synchronization operation problems of co-simulation model are analyzed. The accuracy of co-simulation model is validated by LVRT test data.(2) The LVRT performance of DFIG wind turbine with different lengths of blades are analyzed. Then, the correctness of theoretical analysis is verified by co-simulation model. The effect of pitch system drive motor replacement on LVRT characteristics is also analyzed.(3) The effect of change in generator on LVRT characteristics of DFIG wind turbine are studied. Based on flux linkage method, the stator and rotor transient currents during voltage drops are analyzed. Then, through co-simulation model, the influence of generator parameters to LVRT characteristics of wind turbines are analyzed, and the correctness of the analysis is verified.