Increasing the required slip range of wound induction generator in wind power systems

Eddy currents losses in the rotor in high power generators do not allow
operators, under high values of slip, to regulate voltage and control
of reactive power flow. The paper presents a method that can accurately
estimate the eddy current losses in electric machines with a less complicated
procedure. The suggested method allows researchers to analyze and reduce
the losses, and consequently, to improve the wind turbine induction
generators efficiencies. The given approach, based on the conventional
electric machine theory and the parameters supplied by the manufacturers,
predicts the eddy current losses theoretically without the need of
the measured material loss data or BH curve. Increasing the range of slip
variation of induction motor can be achieved by using a rotor of two layers
in the radial direction with different parameters. The first layer is a laminated
layer of height (h), and the second is a solid (the rotor yoke).
The computation of eddy current losses is useful to change the design
of the machine to minimize the losses. This paper presents a detailed
modeling of the effect parameters on the eddy current losses in wind turbine
induction generator.