Interfacing renewable energy sources for maximum power transfer—Part I: Statics

The manuscript presents a method of interfacing renewable energy generators by means of Maximum Power Line tracking rather than Maximum Power Point tracking. The maximum power line connects the maximum power points of output I–V curves of a source for different values of power producing parameter (wind, solar insolation etc.) and may be estimated offline with moderate accuracy. As a result, during the online operation, the maximum power point tracker only has to compensate for maximum power line inaccuracy and changes caused by slow temperature variations and system parameters drift. The approach allows reducing dramatically the bandwidth of the MPP tracking algorithms and simplifying the implementation, making analog MPP trackers a viable choice. The proposed method is shown to be a generalized version of the well-known loss-free resistor concept, referred to as loss-free load in the manuscript. Several particular case examples of the proposed method presented in the literature are reviewed.