Control and Dynamic Analysis of Grid Connected Variable Speed SCIG Based Wind Energy Conversion System

Strict environmental regulations and shrinkage of fossil fuels necessitate the generation of electrical power by using renewable energy sources. Wind energy is the most promising and popular source of green electricity. Wind energy conversion systems using SCIGs with full scale power converters is a meritorious option as these generators are simpler than the other types available and requires no brush or slip rings. SCIGs are easily available at lower cost, require low maintenance and rugged for any harsh environment. Further, improvements in power electronics makes this option attractive to be used for wind power generation at variable speeds. This paper proposes the modeling, simulation and analysis of an SCIG based WECS when the system operates under varying wind velocity conditions. Vector control strategy is employed for the converters connected, back to back, between generator and the power grid. Generator control is applied for power optimization when wind speed is less than rated speed and pitch control is applied for speeds higher than rated speed but below cut-out speed. Behavior of the same system is studied for single phase to ground fault as it is the most common and frequently occurring fault in power systems.