Adaptive Multi-objective Sliding Mode Control of a Wind Energy Conversion System Involving Doubly Fed Induction Generator for Power Capture Optimization

We consider the problem of controlling wind energy conversion systems that are based on doubly fed induction generators. The aim is to design a nonlinear controller to fulfill the control goals considering the two sides, grid and rotor side. On the rotor side, the control objectives are twofold: (i) ensuring the maximum power point tracking requirement and (ii) maintaining the stator reactive power at a desired reference. On the grid side, we also seek the achievement of two control objectives: (i) regulating the DC-link voltage at a given reference value and (ii) ensuring a zero reactive power. Besides the multi-objective nature of this study, the difficulty of the control problem lies in the nonlinearity and uncertainty of the system dynamics and external disturbances. The control problem under consideration is dealt with by designing a model-based controller using the adaptive sliding mode technique. The stability and performances of the closed-loop control system are analyzed both theoretically and by numerical simulations. The latter are performed using 2MW grid-connected wind turbine system in MATLAB/SIMULINK/SimPowerSystems environment. The simulation results confirm that the suggested controller meets its objectives and features robustness properties.