<span lang="EN-US">When severe voltage sags occur in weak power systems associated with grid-connected wind farms employing doubly fed induction generators, voltage instability occurs which may lead to forced disconnection of wind turbine. Shunt flexible AC transmission system devices like static synchronous compensator (STATCOM) may be harnessed to provide voltage support by dynamic injection of reactive power. In this work, the STATCOM provided voltage compensation at the point of common coupling in five test cases, namely, simultaneous occurrence of step change (drop) in wind speed and dip in grid voltage, single line to ground, line to line, double line to ground faults and sudden increment in load by more than a thousand times. Three techniques were employed to control the STATCOM, namely, fuzzy logic, particle swarm optimization and a combination of both. A performance comparison was made among the three soft computing techniques used to control the STATCOM on the basis of the amount of voltage compensation offered at the point of common coupling. The simulations were done with the help of SimPowerSystems available with MATLAB / SIMULINK and the results validated that the STATCOM controlled by all the three techniques offered voltage compensation in all the cases considered.</span>

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Smart grid is an advancement of the existing electrical grid. The most important aspect of the future smart grid is decentralization of the existing electrical grid into number of smaller grids, which are also called as micro grids. The key feature of the smart grid is the amalgamation of distributed energy resources (DER) with the main grid. The extensive integration of distributed energy resources in power grid causes increase in the value of the fault current. Increased fault current is a serious trouble which has to be overcome for successful accomplishment of smart grids. Superconducting Fault Current Limiter (SFCL) is innovative equipment which has the potential to limit the fault current in the smart grid. It reduces the value of the fault current within first peak of the fault current. The suitable place of SFCL in the smart grid has to be described to obtain the benefit of its incorporation in the smart grid. In this paper the working of SFCL under normal and fault condition has been explained using matlab simulation and result of simulation is shown and for determining its appropriate location in the smart grid 10 MVA wind farm is integrated with the distribution network of the conventional power grid and three phase to ground fault is created at three different locations in the smart grid. For each created fault SFCL position is assessed in the grid to determine its most appropriate place in the grid i.e. place at which it provides maximum suppression of fault current from the wind farm as well as from the conventional power plant.

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