Improving Annual Energy Production of Doubly-Fed Induction Generators

Doubly fed induction generator (DFIG) based wind turbines are most employed for onshore applications because of their cast-effectiveness. The drivetrain improvement is barely studied due to the maturity of the DFIG based systems. This paper investigates two methods for improving the annual energy production (AEP) of the DFIG based wind turbines. They are referred to as short-circuited and Delta-Y-connected DFIGs. The origins of the AEP improvement are elaborated from the drivetrain perspective. The improvement is quantified by the aerodynamic model of the turbine and the steady-state model of the DFIG. The two methods are then compared when applied to six regions with different wind speed distributions. The AEP improvements at six regions are evaluated and compared to derive the feasibility of the methods for different locations.