A Transformerless Step-Up DC-DC Converter

ABSTRACT: In distributed generation (DG) systems, interfacing photovoltaic (PV) energy based sources to the grid poses a number of problems. Nowadays, transformerless converters are preferred for higher efficiency, low size and cost. Such a converter has its own problems. The output voltage of PV arrays is relatively low, requiring a high step-up converter to obtain the DC voltage input of the inverter. In this project, a new step up converter proposed in a recent work [1], is analyzed, designed, simulated with MATLAB Simulink and practically implemented. Besides, the performance and effectiveness of some standard and improved boost converter circuits are discussed and compared in terms of voltage gain, power loss and switch voltage stress requirement. In fact, those performances are examined with deriving formulas and equations of current, voltages, power loss and voltage gain. A major aim of the project is to investigate the effectiveness of this converter regarding application in DG systems. The improved effectiveness due to the lower power loss invoked with such a converter, which at the same time possesses a high voltage step up gain and a lower switch voltage stress compared to the standard boost converter. These characteristics together are attractive feature for use with DG systems. Keywords: Transformerless, Boost Converter, Voltage Gain, DG Systems. ……………………………………………………………………………………………………………………………………………………………………………………………………………………