Novel high-efficient unified maximum power point tracking controller for hybrid fuel cell/wind systems

Abstract

There are different maximum power point tracking (MPPT) methods applicable to fuel cell (FC) systems, but they are not used in a hybrid system including a FC subsystem because a separate MPPT unit should be dedicated to the FC subsystem that significantly complicates the system implementation, and increases cost. This paper addresses this problem by presenting a novel fast and highly accurate unified MPPT technique for hybrid FC/wind systems. The novelty of the technique is that it uses a unified algorithm to concurrently track the maximum power points (MPPs) of the FC and wind energy conversion (WEC) subsystems combined to each other to form a hybrid FC/wind system. Moreover, the technique is sensorless (low-cost), and tracks the MPP of the WEC subsystem, not the MPP of its wind turbine, so it extracts the highest electrical power from the WEC subsystem. A hybrid FC/wind power system has been constructed, and it is verified that the MPPT efficiency of the technique is 99.41% and 99.28% respectively in the FC stack and WEC subsystem, and the convergence time of the algorithm used in the technique is at most 15ms. Comparing the proposed unified MPPT technique to the state-of-the-art MPPT techniques demonstrates that it has the highest MPPT efficiency and the shortest convergence time, while it concurrently tracks two MPPs but others track only one MPP, and this is the other contribution of this work.