Hybrid Fuzzy Controller Based Wind Generator Stability by using STATCOM

Abstract

FACTS devices can be used in wind power systems to improve the transient and dynamic stability of the overall power system. Because of the asynchronous operation nature, system instability of wind farms based on FSIG is largely caused by the reactive power absorption by FSIG (Fixed Speed Induction Generator) due to the large rotor slip during fault. A Static Synchronous Compensator (STATCOM) is applied to a power network which includes a SCIG driven by a wind turbine, for steady state voltage regulation and transient voltage stability support. The STATCOM is controlled by using PQ controller technique with voltage regulation as basic scenario. STATCOM improves the transient voltage stability and therefore helps the wind turbine generator system to remain in service during grid faults.  The time to reach steady state torque and speed without using vector control or direct torque control can also be achieved by using this STATCOM control technique. This paper provides an optimized STATCOM control for wind electric generator. The  transient  behavior  of  fixed-speed  wind  farms  can  be  improved by injecting large amounts of reactive power during the fault  recovery.  This application  requires  a  high  dynamic  converter,  which  must  also  be  capable  of  working  under  transient  unbalanced  conditions. The reactive power demand by squirrel cage wind electric  generator (SCWEG)  during  grid  faults  is  not  met  by  capacitor  banks  installed  near  SCWEG.  This project analyses the transient stability margin of SCWEG which can be increased to a great extend by means of STATCOM.  Here the application of Static Compensator (DSTATCOM) for restoring the voltage level at the Wind Farm terminals under fault conditions is considered. Reactive power confirm that the STATCOM provide clear transient stability margin increase by using MATLAB/SIMULINK