Protection and Fault Analysis of Type 3 Wind Turbine /

Abstract

With an increased installation of renewable energy resources into the grids, the use of power electronics-based devices are increasing day by day. Among the existing renewables, wind turbine technology is heavily dependent on its electronic converters. For this reason, that the maximum dependency of such converters makes it important, that the protection and modeling of large wind turbines system is a prominent challenge in modern power systems. Whenever grid faults occurs, it can cause significant over currents and over voltages, placing the entire facility at risk. It quickly cause the converter system to deteriorate if countermeasures were not taken. Furthermore, Lightning strikes and switching transients also results in the over voltages and it may damage the converter. So a proper protection scheme is needed to protect wind turbine. In this thesis, modeling, control, steady-state validation of DFIG and protection scheme are presented. This thesis discusses the protection of wind turbines based on DFIG from to grid faults. The pitch control along with vector control scheme were done for modeling of such wind turbine. The proposed protection scheme in which the chopper and crowbar protection were modeled. The activation of DFIG protections such as DC chopper and crowbar protection during both symmetrical and unsymmetrical faults was analyzed. For the protection against lightning and switching transients the surge arrester device were installed. Study were done that such protection devices working properly or not and the impact of faults, lightning and switching transients effects the performance of converters which may lead to the life degradation of such converters. The DFIG based wind turbines must have produced power and must stay connected to the grid according to grid code for the Lower Voltage Ride Through (LVRT) and High Voltage ride Through (HVRT) requirements of the renewable energy projects. Reliable operation of power system such grid-connected wind turbines have to be worked properly without and during grid faults and during lightning and switching transients. The FFCEL Wind Power project which is situated in Jhimpir, Sindh, Pakistan. Which have a total of 33 Nordex S77 1.5MW wind turbine having total installed capacity of the 49.5 MW. The simulation were done in Power Systems Computer Aided Design PSCAD for different Voltage dips and lightning studies.