Enhancing the Performance of Wind - Energy - Driven Double - Fed Induction Generators

Abstract

The utilization of wind energy driven induction generators finds nowadays great interest. The present paper aimed at improving the performance of the induction generators at the different expected wind speeds employing control techniques from the rotor side. A set of two converters in the rotor circuit has been adjusted to inject a voltage such that the generator runs at the speed which allows the wind turbine to extract the maximum power from the wind, and at the same time to deliver the electrical power to the network at unity power factor. The double-fed induction generator has been modelled at steady-state conditions using frequency domain equivalent circuit. The performance characteristics of both double-fed induction generator (DFIG) and single-fed induction generator (SFIG) have been computed. The computed performance characteristics have revealed that the DFIG has superior performance characteristics as compared with the SFIG. The output active power of the generator has been clearly increased by double-feeding especially at wind speeds far from the base speed. Also, the DFIG nearly does not consume reactive power when compared with SFIG. Although the output power of the generator is clearly increased by doubly feeding it, the stator and rotor currents still within their rated values. Keywords: Wind Energy, Double-fed Induction Generator, Optimization