Enhanced Differential Power Processor for PV Systems: Resonant Switched-Capacitor Gyrator Converter With Local MPPT

This paper introduces an enhanced differential power processor topology and principle of operation for photovoltaic (PV) systems that is based on switched-capacitor technology, featuring local maximum power point tracking (MPPT) capability, zero current switching, high efficiency over wide-operation range, and reduced size. The new converter operates as a voltage-dependent current-source and is regulated by dead-time or frequency control. Local MPPT on the individual PV elements is realized and the operation is demonstrated by simulation and experiments. Differential power processing operation is verified using 150-W prototypes, demonstrating ultimate improvement in the power harvesting capability of above 90% and up to 99% out of the available power in the string, under different insolation levels.