Cross-Coupling Effects of Interconnected DC-DC Converter System in PV Applications

Abstract

Due to increase in global warming,the world is renewing its focus on renewable sources of energy.Among them, Photovoltaic(PV)generation has attracted vast interests worldwide.In PV generation, solar photovoltaic panels absorb solar radiation to generate power through photovoltaic effect.However,the PV systems are found to be vulnerable to mismatch conditions and other atmospheric conditions.So,to extract maximum power under partial shading condition and module mismatching,calls for new innovation methods and technologies.In this thesis,the modelling of a PV module is discussed.The characteristics of photo-voltaic module are observed for various solar irradiation and different atmospheric condition.The PV panel is operated at its maximum power point by using P & O method and the duty cycle control is being employed to get the peak power.The photovoltaic modules are connected in series to get the high voltage of system.The classical MPPT control method does not work when the photo-voltaic modules are connected in series,under extreme conditions and under partial shading.Thus,Distributed Maximum power point tracking(DMPPT)control method is used to extract power under such conditions.However,due to cascading of dc-dc converters,there is a surprise element of cross-coupling effects.The coupling effects are the disturbances which are present in the system because of cascading of dc-dc converters.Cross-coupling effects are studied in this thesis.