Maximum power point modeling through irradiance-based duty cycle calculation

Abstract

This paper proposes an irradiance based modeling of duty cycle, for maximum power point operation of a panel. In existing methods for irradiance prediction, a relation was established to input maximum power duty cycle with parameters of panel. Proposed system operated with better maximum power point based on panel parameters duty cycle relation. Duty cycle of the converter is independent of feedback from output side so that the necessity of voltage sensing was eliminated and duty cycle input to converter was calculated from irradiance input on panel. Irradiance data for last 10 years was collected from NASA’s website and for various level of irradiance Vmp, Imp are modeled to ensure maximum output power from converter. Duty cycle is then calculated with converter topology to trigger switch. Modeling of proposed system was done with different irradiance levels to calculate duty cycle for a year. Then obtained model was verified at predicted irradiance levels and a maximum point operation up to 98.21% was obtained. In various parameters of solar panel maximum power voltage, maximum power current and load side impedance was taken for duty cycle calculation. This proposed research work based on input effective resistance and output resistance is useful in constant voltage demand applications like battery charging or to supply constant dc load