Differential power processing (DPP) is a power electronics system architecture that configures DC-DC converters in parallel with the PV string to improve its power yield. The parallel nature of the DPP architecture brings a number of benefits, such as low converter power rating and low power losses, all of which make DPP especially suitable for submodule-level maximum power point tracking (MPPT). This project is researching the submodule-level MPPT control in switch-inductor based DPP architecture with high speed of convergence speed, which is facing the complex and changeable environment.