Comparative study of different Bridge Fault Current Limiters applied in Doubly Fed Induction Generator for Improvement of Fault Ride-Through Capability

摘要

The behavior of a grid-connected Doubly Fed Induction Generator following the occurrence of a fault in the grid has become quite significant from the stable operating point of view. The need for maintaining grid voltage at the time of faults has become very important and the same can be said for the reactive power compensation to the system after the fault clearance. This has necessitated the formation of new grid codes comprising of Low Voltage Ride-Through as one of the major requirements for the integration of wind farms to the grid. The wind farm model is represented by an equivalent array of DFIGs. Temporary Three-Line-To-Ground (3LG) fault was applied to one of the double circuit transmission lines of the test system to investigate the LVRT. In this paper, a study has been carried out to compare the performance of DFIG with and without a Fault Current Limiter (FCL). Further, the performances of Inductive-Resistive Type Bridge Fault Current Limiter (LR-BFCL) and Capacitive-Resistive Type Bridge Fault Current Limiter (CR-BFCL) have been compared. CR-BFCL has been found to give better Fault Ride Through which can be attributed to reactive power injection by it during fault clearance. MATLAB/Simulink environment is used to carry out simulations. The graphical results obtained from simulations show that the CR-BFCL effectively provides reactive power compensation besides improving the Fault Ride Through capability.