Industrial Electronics
Mahdi Elmi; Mohamad Reza Banaei; Hadi Afsharirad
Abstract
The objective of this paper is to propose, study and analyze a non-isolated high step-up SEPIC-based DC-DC converter for photovoltaic applications. The proposed structure is based on the SEPIC converter and utilizes a two-winding coupled inductor along with an improved voltage multiplier cell in order ...
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The objective of this paper is to propose, study and analyze a non-isolated high step-up SEPIC-based DC-DC converter for photovoltaic applications. The proposed structure is based on the SEPIC converter and utilizes a two-winding coupled inductor along with an improved voltage multiplier cell in order to enhance the output voltage level. Moreover, a passive voltage clamp is used to reduce the voltage stress on the main switch and recover the energy stored in the leakage inductance of the coupled inductor. Hence, an active switch with low RDS-ON could be employed. Meanwhile, due to soft switching condition at turn-off instant of diodes, their reverse-recovery problems are solved. Furthermore, the presented converter has the merits such as continuous input current, high efficiency and low cost and size which make it a promising solution for photovoltaic applications. At the end, the converter is compared to different types of DC-DC converters to show its advantages over the converters designed before. In order to verify the performance of the converter, a 200-W laboratory prototype is implemented and experimental results are taken and depicted. Results prove the feasibility and functionality of the presented converter for photovoltaic systems.
Industrial Electronics
Mahmoodreza Eskandarpour Azizkandi; Farzad Sedaghati; Hossein Shayeghi
Abstract
A new non-isolated, coupled-inductor, single-switch boost DC-DC converter for photovoltaic (PV) power application is introduced in this paper. A coupled inductor and voltage multiplier cells is used in the presented converter to obtain a high voltage conversion ratio. Also, a passive clamp circuit is ...
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A new non-isolated, coupled-inductor, single-switch boost DC-DC converter for photovoltaic (PV) power application is introduced in this paper. A coupled inductor and voltage multiplier cells is used in the presented converter to obtain a high voltage conversion ratio. Also, a passive clamp circuit is applied in the converter structure to reduce voltage stress of the power switch. This leads to using a power switch with lower on-state resistance in the converter which decreases the conduction loss. In addition, zero current switching (ZCS) condition for the power switch is achieved due to the use of the clamp circuit. Several advantages such as low operating duty cycle, high voltage conversion ratio, reduced voltage stress of semiconductors, low turn ratio for the coupled inductor, leakage inductance reverse recovery and high efficiency operation make the presented converter suitable for renewable energy applications. The steady state operation of the suggested structure in continuous conduction mode (CCM) and discontinuous conduction mode (DCM) is expressed and analyzed. Then, the presented topology is compared with several similar high gain topologies to prove its advantages. Finally, experimental measurement results of a laboratory prototype of the proposed DC-DC converter with about 213W output power and 435V output voltage at 50 kHz switching frequency are presented to corroborate its feasibility and performance.
