Simulation of a site-specific doubly-fed induction generator (DFIG) for wind turbine applications

This paper describes a preliminary study of a 30 kW doubly-fed induction generator (DFIG) used for wind turbine applications. Wind represents a variable-speed intermittent source of energy in nature and can be controlled to be a nearly constant speed but variable-torque input to the wind turbine using blade pitch angle regulation. Wind profile at the installation site is investigated so as to derive parameterized wind speeds, more importantly, the annual cubic-mean speed. This is taken account into the machine design since the machine efficiency varies with turbine mechanical inputs. By coordinating the loss components, it is possible at the machine design stage to select the maximum efficiency to be near the actual optimized load, in a long run, to maximize the overall energy production of the generator. The DFIG is modeled in Matlab with a vector control. The total energy production is used as a key criterion to refine the machine design.