A novel transformer less high step-up buck–boost DC-DC Converter is proposed in this paper. The output voltages of some sources such as fuel cell, photovoltaic are not regulated. Therefore voltage regulation is required to fix the DC-link voltage. Hence, a buck boost DC/DC Converter is suitable to regulate the output voltage of these sources. The presented Converter voltage gain is higher that of the conventional boost, buck boost, CUK, SEPIC and ZETA Converters and high voltage gain can be obtained with a suitable duty cycle. In this Converter, only one power switch is utilized. The voltage stress across the power switch and diodes is low. Hence, the low on-state resistance of the power switch can be selected to decrease conduction loss of the switch and improve efficiency. The low voltage stress across the diodes allows the prevent the reverse-recovery current problem. The proposed Converter can be operated in the continuous conduction mode (CCM) and the discontinuous conduction mode (DCM). The presented Converter has simple structure; therefore the control of the proposed Converter will be easy. The principle of operation and the mathematical analyses of the proposed Converter are explained. The validity of the presented Converter is verified by the experimental results.

In this paper, a new Countinous Current Mode (CCM) nonisolated DC-DC interleaved Converter is proposed that uses an auxiliary circuit to create soft switching conditions. The auxiliary circuit used in this Converter has no switch and provides soft switching conditions for all switching elements from only one resonance path. Also, the designed auxiliary circuit is not located in the power transmission path from input to output. Due to the use of interleaved structure, the current stress on the switches in the proposed Converter is low. This Converter has a very simple structure and operation compared to similar structures. The Converter control method is also simple and pulse width modulation (PWM) is used to command the switch. Due to soft switching technique, the switching frequency of the Converter has increased, this way leads reduced the size and overall volume of the Converter, especially the passive elements in the structure, switching and conduction losses and also increased the efficiency of the Converter compared to similar structures. Also, the proposed Converter with 48V input voltage, 155V output voltage with 100 kHz switching frequency at 900 watts was simulated in PSPICE software. The results of simulation and theoretical and computational analysis confirm the performance of the Converter.

High step-up DC-DC Converters are considered the main components of some lowvoltage and low-power fuel cell power system applications. A new DC-DC Converter topology based on a two-stage switched capacitor-switched inductor multiplier is proposed in this paper. In comparison with other conventional and high step-up DCDC Converters, the proposed Converter topology provides higher voltage gain and lower switch voltage stresses for duty cycles in the range of 0. 6 or higher, the typical duty cycle of high step-up DC-DC Converters. The proposed Converter consists of a novel combination of switched capacitors and switched inductors methods that reduce the number of required switches and their duty cycles. The theoretical analysis was confirmed by simulation results in MATLAB/Simulink software environment results. A 100 W laboratory prototype of the proposed Converter was implemented to investigate and validate the analytical and simulation results. The prototype DC-DC Converter was designed and implemented for use in a commercial 100 W PEM fuel cell stack power system.

In this paper, a new high step-up current-fed LLC resonant DC-DC Converter with a center-tapped transformer is proposed. By selecting the switching frequency to be lower than, but near to, the series resonant frequency of the LLC resonant tank, soft-switching operation of all semiconductors, i.e., zero voltage switching (ZVS) turn-on of power MOSFETs and zero current switching (ZCS) turn-off of diodes is achieved. This leads to lower electromagnetic interference (EMI) and lower switching losses and improves the Converter efficiency. An interleaved structure is used at the primary side. Thus, input current ripple is smaller, and its frequency is twice the switching frequency. Consequently, a smaller input filter is necessary in practice. The Converter with 1.2 kW output power and 760 V regulated output voltage with 80-200 V input voltage variations is simulated. The output voltage is regulated by using asymmetric pulse width modulation (APWM) at 200 kHz switching frequency. Finally, a 700-W prototype has been implemented and experimental results are also presented to verify the simulation results.

This paper proposes a multi-stage power generation system suitable for renewable energy sources, which is composed of a DC-DC power Converter and a three-phase inverter. The DC-DC power Converter is a boost Converter to convert the output voltage of the DC source into two voltage sources. The DC-DC Converter has two switches operates like a continuous conduction mode. The input current of DC-DC Converter has low ripple and voltage of semiconductors is lower than the output voltage. The three-phase inverter is a T-type inverter. This inverter requires two balance DC sources. The inverter part converts the two output voltage sources of DC-DC power Converter into a five-level line to line AC voltage. Simulation results are given to show the overall system performance, including AC voltagegeneration. A prototype is developed and tested to verify the performance of the Converter.

In present research in order to reduce emitted pollutant gases from vehicles, design and production of metallic catalyst Converter have been studied. The specimens are adjustable on different engines with different capacity. For this purpose the following steps were carried out:The first step is preparation of a-4 sheet consists of annealing, forming and making monolith. The second step contains providing wash coat and catalyst metals and coating them on washed coated monolith. The last step is canning of catalyst Converter. After accomplishing above steps, required tests have been done as below:Measurement of emitted pollutants from vehicles, stability of catalyst Converter in vehicle (road test) and finally measurement of amount of fuel consumption of vehicles with different used catalyst Converters in them.Results of these tests showed that emission of CO was equivalent with Euro3 standard and NOX emission was equivalent to Euro4 standard and NOX+HC emission was equivalent with Euro3 standard.

Estimation of site response from an earthquake is fundamental step to anticipate the possible damages and so the objective of a site response analysis is to estimate the ground shaking during an earthquake. In this paper the effect of nonlinearity on site response analyses summarized and evaluating ground surface response taking into account the local soil and subsurface soils properties for the proposed bridge at Sirdjan Balvavard road subjected to earthquake provokes with Standard Hyperbolic Model for nonlinear condition was executed. This area is prone to high seismic risk due to the presence of several active faults and therefore quantifying the site effect on the surface over a number of geotechnical areas has been notified. For site characterization, deep site investigations have been undertaken, and a seismic geotechnical procedure has proposed. The effect of nonlinearity on site response analysis for the selected site with assumption of elastic and rigid half space bedrock by use of Standard Hyperbolic Model was evaluated and the results of them over a number of geotechnical areas were compared to each other. Critical point of this work was to design, develop and use a seismic geotechnical based computer code by authors which named as "Abbas Converter". It has several advantages, which can make facilitate this study more than previous have done and take over the encountered problem. This study clearly showed the applicability of "Abbas Converter" on evaluation of site response with bedrock type assumption on soil behavior under the earthquake excitations.