Abstract: In present days, the usage of power electronic devices is increasing rapidly specially in switched mode power supply, (SMPS) units which are used in various applications like cell phone chargers, adaptors for laptops and powering to LED circuits etc., The dc Ė dc converters plays major role in these SMPS for changing the voltages from one level to another level as per the load demand. Thus, the traditional converters, such as boost and fly back converters are not suitable for high step conversion because of the extreme duty cycle (or) high turnís ratio. In this project a high step-up dc-dc converter with high voltage gain is analyzed for renewable energy systems.it has potential advantages of simple structure, high efficiency, low voltage stress, low emi. As the photovoltaic (PV) arrays fuel cells and super capacitors produce low output voltage (12-30) and this voltage is boosted up to (350-400). In this project a single switch high step up converter is analysed. It is simulated in closed loop controllerís voltage mode control, current mode control, and fuzzy logic control is used. The output voltage regulation is maintain constant. When source & load is sudden rise or fall the voltage regulation is constant. To decrease switching loss and to increase the efficiency of the converter.

Keywords: High Step-Up, DC-DC, SEPIC, Renewable Energy.