In this research, the design of a nonlinear rotor side controller is developed for a wind turbine generator based on nonlinear, H2 optimal control theory. The objective is to demonstrate the synthesis of a Maximum Power Point Tracking (MPPT) algorithm. In the case of a doubly fed induction generator, it is essential that the rotor side controller and the MPPT algorithm are synthesized concurrently as the nonlinear perturbation dynamics about an operating point is either only just stable or unstable in most real generators. The algorithm is validated based on using non-linear estimation techniques and maximizing an estimate of the actual power transferred from the turbine to the generator. The MPPT algorithm is successfully demonstrated both in the case when no disturbances were present, as it is a prerequisite for successful implementation and in cases when significant levels of wind disturbances are present.
Related Publication: “Nonlinear, Optimal Control of a Wind Turbine Generator,” IEEE Transactions on Energy Conversion, Volume: 26 No. 2, pp.: 468 - 478, June, 2011 , ISSN: 0885-8969, DOI: 10.1109/TEC.2010.2087380.