Predictive Optimal Torque Control for Permanent-Magnet Synchronous Generators in Wind Turbine Systems

This paper introduces a predictive optimal torque control (POTC) for permanent-magnet synchronous generators (PMSGs) based on variable-speed wind turbine systems. Firstly, the reference torque is computed by employing a maximum power point tracking (MPPT) technique without the need to measure the speed of the wind by using mechanical sensors, which improve the reliability of the control system. Then, a prediction model for the torque and current of d-axis of the generator is derived. After that, an optimization function is used to find the best switching action to be applied on the power converter in the next sample. The introduced POTC technique is validated by experimental results using a dSPACE DS1007 real time platform and a 14.5 kW PMSG under several operation conditions. The experimental results illustrate excellent dynamic performance, i.e. very quick ability to track the reference values. Furthermore, very good steady-state performance is obtained as well.