Real Power Control: MPPT and Pitch Control in a DFIG Based Wind Turbine

Variable speed wind systems are widely used in Wind Energy Conversion Systems (WECS), especially with Doubly-Fed Induction Generators (DFIG). They operate within four different regions depending on wind speed. For low to medium wind speed, the wind system uses a Maximum Power Point Tracking (MPPT) algorithm to generate the maximum power. For medium to high wind speed, the system uses pitch control to fix the rotational speed of the turbine and generate the rated power. This paper focuses on elaborating a dynamic model and control of real power of a 1.5MW wind system based on DFIG. Two-mass model of the turbine and Park transform model of the generator are used. As for the control, it is ensured by an MPPT algorithm without speed control and a PI controller designed based on Taylor Linearization for the pitch control. Performances of the control algorithm are examined through simulations in Matlab/SIMULINK environment, during supersynchronous and subsynchronous operating modes.