A distributed approach to MPPT for PV sub-module differential power processing

This paper presents a distributed control algorithm for differential power processing in photovoltaic (PV) applications. This distributed algorithm performs true maximum power point tracking (MPPT) of series-connected PV sub-modules with only neighbor-to-neighbor communication and local measurements of each differential power converter voltages, obviating the need for local current measurements. Reduced number of perturbations at each step and potentially faster tracking can be achieved compared to previous solutions, while no extra hardware is required, all of which make this algorithm well-suited for long sub-module strings. The formulation of the control algorithm as well as three case studies are presented; both simulations and hardware experiments have confirmed the effectiveness of the proposed distributed algorithm.