Investigations into methods of maximizing the power output of partially shaded PV based distributed generation

Abstract

Photovoltaic (PV) based distributed energy generation has gained a lot of attention during the last couple of decades. The two major issues with the PV system are the partial shading and low efficiency of the PV cells. This research is aimed to investigate various aspects like PV array configurations, DMPPT configurations, level of DMPPT, types of converters etc. on the performance of the PV system in terms of output power, number of components, complexity etc.. The research proposes limited DMPPT approach and evaluates the compromise to be made on the aspect of output power when working with the different limited DMPPT approaches. The quasi DMPPT approaches TCT-CC and TCT-GCC are also presented and evaluated with a view to minimize the cost by decreasing the number of converters and sensors. The superiority of MCHGC based grid-connected CHB-MLI in terms of extracting higher power and feeding good quality power to the grid under non-uniform conditions is presented. The inverters associated with the PV systems can play a role in reactive power exchange as well. A reactive power sharing algorithm is presented in a way that it effectively utilizes the available reactive margin of the inverters and shares the reactive power amongst the inverters to ensure effective utilization is nearly same. Further, it ensures that the total loss in the inverters, while achieving the above objective of equal apparent power sharing, is kept to the minimum. This PhD Thesis would be helpful for increasing output power of PV system with minimum cost of the system during partial shading condition. newline newline