Performance evaluation of DC grid connected solar PV system for hybrid control of DC-DC boost converter

This paper mainly focuses on integration of distributed generation to a DC grid. The performance of grid connected solar PV system is evaluated using hybrid control of DC-DC boost converter. The hybrid controller proposed here includes MPPT controller and fuzzy logic controller. MPPT controller using incremental conductance technique is used to track the maximum power from the PV source, whereas fuzzy logic controller is used to maintain stable DC output according to the grid requirement by adjusting the duty cycle. The outputs of the PV fed DC-DC Boost converters are connected in series and finally the series connected output is tied up to the DC grid. While one of these DC-DC Boost converters will take care of MPPT, the other will function as voltage regulating agents thus achieving the dual functionality of MPPT as well as voltage regulation of the DC bus. Both are achieved with the help of independent duty ratio control of various DC-DC Boost converters integrated with the individual solar PV units. Modeling and simulation of proposed system is performed in MATLAB/SIMULINK environment. The results presented show that the controller for the individual DC-DC Boost converters are able to maintain the DC link voltage apart from harvesting maximum power from the solar PV irrespective of variation in the insolation at the input and load variation.