Sub-module differential power processing for photovoltaic applications

In this paper, a sub-module differential power processing (DPP) architecture for solar photovoltaic (PV) applications is presented, along with a maximum power point tracking (MPPT) control scheme that requires minimum communication and no local current sensing. The efficiency, size and cost benefit of this architecture are analyzed, and the control challenges associated with this architecture are addressed. A hardware prototype is implemented and tested in a controllable indoor test setup that enables replication of real-world partial shading conditions. We experimentally verified a substantial increase in total system energy capture compared to module-level MPPT solutions, through the use of the proposed DPP architecture and control strategy.