Proposed control policy for stabilized DFIG energy transducer

This paper aims to extract maximum power from wind turbine at all permissible wind speed range at reduced total copper loss of the Doubly Fed Induction Generator (DFIG) simultaneously. A proposed steady state model is presented whereby unity rotor power factor (URPF) of the DFIG and wind - turbine speed variables are the state variables. The URPF proposed variable is the load angle α by which the generator steady state performance characteristics are controlled over the whole operating speed range. Comparison between URPF, constant flux and constant rotor voltage magnitude operating modes is given to illustrate and evaluate the generator performance characteristics at URPF up two twice synchronous speed. Further, a proposed analytical approach has been implemented to predict the optimal load angle and the speed dependent rotor voltage magnitude that insures MPPT at URPF specified for wind energy conversion. This speed dependent rotor voltage magnitude may be burnt into the EPROM of the digital reference generator provided by a rotor side converter in DSP system.