Abstract:
This thesis conducts the design and simulation of a simple but efficient photovoltaic water pumping system and this work also analyzes a mathematical linear programming based graphical model to provide the best economical solution for water pumping system by comparing hybrid, solar-only and wind-only system. It provides theoretical studies of photovoltaic and modeling techniques using equivalent electric circuits. The system employs a new maximum power point tracker (MPPT) which is suitable for rapid changing weather conditions. The investigation includes discussion of various MPPT algorithms and their comparisons and drawbacks and it has been shown that the proposed model has been successfully resolved the drawbacks from existing models. A mathematical model of DC motor has also been developed using actual output characteristic data and verified using MATLAB simulations. MATLAB simulations are also performed for comparing the number of iterations before reaching to MPP point of the proposed method and the most popular existingMPPT algorithms using actual irradiance and temperature data and has shown that the proposed model has taken much less number of iterations comparing to existing models and hence makes it suitable for rapid changing weather conditions. It also conducts a performance analysis by comparing the duty cycles and maximum power points with the exact duty cycles and maximum power points and justifies the validity of the proposed model. The thesis work chooses output sensing direct control method which requires two sensors only with a view to making the whole system cost effective. Simulations also make comparisons with the system without MPPT in terms of total energy produced. The results validate that the proposed MPPT algorithm can significantly increase the efficiency and the performance of PV water pumping system compared with the system without MPPT. Finally, the research develops a mathematical graphical sizing technique using linear programming to find an economical solution for water pumping system in two different regions of Bangladesh and found out that for both regions, Khulna and Kutubdia, hybrid system is the most cost effective solution based on the corresponding weather data.
