جستجوی مقالات مرتبط با کلیدواژه « converter » در نشریات گروه « فنی و مهندسی »

In recent few decades, due to various reasons, including energy crisis and environmental problems, renewable energy sources such as wind energy, solar systems and fuel cells have received much attention. Solar or photovoltaic systems are one of the most widely used renewable energy sources that have a low output voltage. For this reason, research on dc-dc converters has increased in recent years. In this paper, a non-isolated high voltage gain converter with three input-output ports is proposed. This converter provides two separate paths for power flow from each input source to the output load. In order to reduce the number of converter components, some components play multiple roles. Therefore, the energy storage device (battery) will charge with the same components used to transfer the power to the load. In this converter, to increase the voltage gain, the coupled inductor technique is used. Moreover, to reduce the leakage inductance as well as achieving the soft switching condition, two active clamps are used. Since the voltage across the switches is limited, the switches can be used with low voltage stress and thus low conduction losses. In this converter, the ripple of the input current will reduce by adding an inductor at its input. This has a significant impact on the performance and the lifespan of the solar cells. The various operational modes of the converter are discussed and the designing considerations are presented. A prototype of the proposed converter is simulated to supply a 130 W, 330 V load with a switching frequency of 50 kHz, in OrCAD software. Finally, a laboratory sample is implemented and the theoretical analysis are validated by the practical results.

In this paper, a non-isolated high step-up soft-switching converter is proposed. The proposed converter is a boost converter combined with two voltage multiplier cells for boosting output voltage. Also, extend voltage gain of the proposed converter is achieved by using a coupled-inductor. Compare with other similar high step-up topologies with the same number of components, the proposed converter has a higher voltage gain and higher efficiency. An active clamp circuit is used so, the zero-voltage switching (ZVS) is achieved. Also, in the proposed converter, the voltage stresses on the switches are low. As the voltage stress decreases on the switch, Ron</sub> of the MOSFET is deceased and as a result conduction loss of the switch is decreased. So, the efficiency of this converter increased. In this paper, operational principle of the converter is described and the analytical, simulated results and prototype converters are validated using a 20V input and 400V </strong>output converter at 200W load.

Nowadays by using more and more Internet and online tools, security has become a major concern for computer system designers. The basis of security, prevention of intrusion, and enemy access to sensitive information is cryptographic algorithms which require complex processing and fast computations. Therefore, computer arithmetic and investigating new methods to improve basic operations such as addition, subtraction and multiplication is of great importance. In digital systems, low-delay computations play an important role, and using a residue number system is one of the ways that can speed up computational operations by parallelizing and reducing the carry propagation chain. In addition, OneHot coding, with its special features, is well compatible with the residue number system to help speed up operations by eliminating the carry propagation. In addition, with the limited changes of input in OneHot coding, the rate of circuit switching is reduced, resulting in reducing a dynamic power consumption comparing with a binary coding system. Therefore, in this article, in order to take advantage of the benefits of OneHot coding in the residue number system, the required components are designed, including adder, subtractor, and multiplier of modules with OneHot coding. The structure of a forward converter to transform inputs to residues in the OneHot format has also been introduced for the first time. The proposed structures have been implemented and have been analyzed and evaluated to investigate their performance.