Differential power processing architecture for increased energy production and reliability of photovoltaic systems

Conventional energy conversion architectures in photovoltaic (PV) systems are often forced to trade off conversion efficiency and power production. This paper introduces a power processing architecture that enables each PV element to operate at its maximum power point (MPP) while only processing a small fraction of the total power produced. This is accomplished by providing only the mismatch in the MPP current of a set of series-connected PV elements. The differential power processing architecture increases overall conversion efficiency and overcomes the challenges of unmatched MPPs (due to partial shading, damage, manufacturing tolerances, etc.). Local control of the differential converters enables distributed protection and monitoring. The reliability analysis included in this paper shows significantly increased overall system reliability. Simulation and experimental results are included to demonstrate the benefits of this approach.