Implementation of microcontroller based Maximum Power Point Tracker (MPPT) using SEPIC converter

This paper presents analysis and design of a Maximum Power Point Tracker (MPPT) which is economical and compact in size. The DC to DC converter used in the system is SEPIC converter which eliminates the use of separate ground isolation circuit and reduces tracking time. The efficiency of this converter is better than traditionally used Buck-Boost converter. Here Incremental Conductance method is used to get a stable output in varying solar irradiance level. The proposed system also includes elimination of PI controller for duty cycle modification, elimination of complex circuit for sensing current and elimination of filters for accurate analog to digital conversion of voltage and currents. This system is tested and verified experimentally with 135Wp solar panel in varying insolation levels.