Sneha George, et. al. International Journal of Engineering Research and Applications www.ijera.com ISSN: 2248-9622, Vol. 11, Issue 3, (Series-II) March 2021, pp. 36-43 www.ijera.com DOI: 10.9790/9622-1103023643 36 | Page A High Gain Bidirectional SEPIC Converter 1 Sneha George. K, 2 Prof. Elizabeth Paul, 3 Prof. Emmanuel Babu. P, 4 Prof. Sera Mathew , 5 Prof. Geethu James 1 PG Scholar, 2 Associate Professor, 3 Assistant Professor, 4 Assistant Professor, 5 Assistant Professor Department of Electrical & Electronics Mar Athanasius College of Engineering, Kothamangalam ABSTRACT With increase in energy demand, the utilization of renewable energy sources like solar and wind energies become important. Energy storage systems with bidirectional converters are essential to overcome the intermittent nature of these renewable sources. In this a non-coupled inductor based SEPIC bidirectional converter having reduced ripple in output voltage and low voltage stress on switches are presented. The converter is simple and some auxiliary components are added to the conventional SEPIC topology to have a higher gain. The non- coupled SEPIC converter is modified into bidirectional SEPIC converter by replacing diodes with switches. The converter has many advantages such as high voltage gain, non-inverting output, continuous input current, high efficiency and lower voltage stress on the switches. Moreover, high voltage gain is achieved without using any transformer and coupled inductor, so there is no voltage over shoot for switches during the turn-off process. The number of components of introduced converter is comparatively lesser than other non-coupled inductor converter. The bidirectional converters are mainly used in applications such as battery charger/dischargers, renewable power systems, electric vehicles, uninterrupted power supplies and micro grid to improve dynamic response and stability of the system. The performance study of the converter is carried out with MATLAB/SIMULINK R2017a. Using FPGA controller pulses for the switches are obtained. Keywords - SEPIC Converter, MOSFET, Non-Coupled Inductor, FPGA --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 10-03-2021 Date of Acceptance: 25-03-2021 --------------------------------------------------------------------------------------------------------------------------------------- I. INTRODUCTION Due to the rapid depletion of fossil fuels, effective utilization of alternate resources to meet the rising energy demand becomes important. The renewable energy resources, such as photovoltaic and wind power, are the best options for clean electric power generation. However, the intermittent nature of these resources introduces issues related to system stability, reliability, and power quality. Energy storage systems (ESSs) are required to deal with such issues. These ESSs should have bidirectional power flow capability to store the excess energy generated by renewable resources, and release it when the energy is not sufficient. The energy storage system play an important role in applications like renewable power systems, electric vehicles, uninterrupted power supplies and micro grid to improve dynamic response and stability of the system. For that a converter is necessary to transfer the energy in both ways. Bidirectional DC- DC converters allow transfer of power between two dc sources, in either direction. Due to their ability to reverse the direction of flow of power, they are being increasingly used in many applications such as battery charger/dischargers, dc uninterruptible power supplies, electrical vehicle motor drives, aerospace power systems, tele- com power supplies, etc. The single-ended primary inductor converter (SEPIC) and buck-boost converter have the ability to step up and step down the output voltage according to its duty cycle. A high gain converter with continuous input current is more ideal to track the maximum power point of PV panels. Therefore, the DC-DC converters which are used in renewable energy must benefit from high step-up voltage gain as well as continuous input current. In [1] introduces a novel non-coupled inductor high voltage gain SEPIC converter. The converter is simple and modification of the SEPIC converter is accomplished by adding only four components. The converter has various advantages such as lower voltage stress on the switches, non- inverting output voltage, high efficiency, and high voltage gain. Also, the introduced converter has a continuous input current which makes it suitable for renewable energy and fuel cell applications. A novel switched-coupled inductor DC-DC step-up converter with high conversion ratio is presented in [2]. A coupled inductor is used to charge a switched RESEARCH ARTICLE OPEN ACCESS