An adaptive approximation method for maximum power point tracking (MPPT) in wind energy systems

An adaptive maximum power point tracking (MPPT) method that combines a master-slave fuzzy logic controller (FLC) and an approximation scheme for wind energy power systems is proposed in this paper. There are two operating modes in the proposed MPPT method: the training mode (governed by the master-slave FLC); and the comparison mode (governed by the line-of-best-fit approximation). In addition to performing the basic maximum power point search, the FLC mode also allows the system to differentiate whether the system changes are due to wind speed variation or due to the search process. The comparison mode constructs an approximation of the system´s power characteristic. This allows it to be independent of ambient changes (e.g. wind velocity, air density, etc.) and to quickly determine the correct adjustments to achieve maximum power capture. Each of these operating modes will be explained in this paper. Simulation results are provided to verify with the proposed control concept.