Fault Analysis and Protection of DFIG Converters In a Wind Farm /

Abstract

Due to rapid increase in the installation of renewable energy resources into the grids, the use of power electronics-based devices are increasing day by day. Whenever a Wind Farm is installed and integrate with the grid, most of work and control depends on its electronic converters. For this reason, the control and modeling of large wind turbines is a prominent challenge in modern power systems. And whenever grid fault occurs, it can cause significant overcurrent and over voltages, placing the entire facility at risk. It quickly causes the converter system to deteriorate if countermeasures were not taken. So, a proper protection scheme is needed to protect the generator and its converter from faults Thus, accurate modeling of Doubly-fed induction generator (DFIG) along with its control is desperately needed. In this thesis, modeling, control, steady-state validation of DFIG and proper protection scheme are presented. Faults analysis and protection scheme are presented in which asymmetrical and symmetrical faults are created and then check its effects on DFIG, rotor circuit and converters. Then a proper protection scheme of Crowbar circuit is designed and check its operation on 1.5MW DFIG based Industrial Wind Turbine model (FFCEL) in EMTDC/PSCAD. To constant DC-link voltage and to produce the maximum power from the wind speed, the vector control technique is designed for both stator and rotor side converters. The simulations are done in EMTDC/PSCAD, and the results were carried out on 1.5MW DFIG of FFCEL Wind Turbine and then validate with the actual data.