Tohid Jalilzadeh

Bio: Tohid Jalilzadeh is an academic researcher from University of Tabriz. The author has contributed to research in topics: Voltage & Capacitor. The author has an hindex of 10, co-authored 18 publications receiving 300 citations.

A New High Step-Up Multi-Input Multi-Output DC–DC Converter

Abstract: In this paper, a new multi-input multi-output (MIMO) dc–dc converter with high step-up capability is proposed for wide power ranges. Also, in order to increase each output voltage, diode–capacitor voltage multiplier (VM) stages are utilized in the proposed converter. The number of input stages, output stages, and VM stages are arbitrary and dependent on design conditions. At first, the general structure of proposed MIMO converter is presented. Then, in order to explain the converter operation, we walk through the design of a 1-kW four-input two-output example, including loss and efficiency calculations. We validate the design with a prototype that matches efficiency calculations.

Six-phase interleaved boost dc/dc converter with high-voltage gain and reduced voltage stress

Abstract: In this study, a new non-isolated six-phase interleaved boost dc–dc converter is presented for photovoltaic (PV) applications. The suggested structure consists of two symmetric three-phase interleaved boost dc–dc converters along with two switched-capacitor cells, in order to obtain high conversion ratio. For different values of duty-cycles, the voltage conversion ratio of the proposed topology is high. Also, the voltage stress of switches for various duty cycles is low and the efficiency of proposed topology is high. Moreover, the value of input current ripple is low with the utilisation of interleaving techniques. These advantages cause the proposed topology to be a good candidate for PV systems. The operation modes and mathematical analysis of the presented converter is introduced. In order to show the merits of presented converter, comparison results with other boost dc/dc converters are provided. Both experimental and simulation works based 453 W are presented to verify the operation of recommended converter. PSCAD/EMTDC software is used for simulation work.

Non-Isolated Topology for High Step-Up DC-DC Converters

Abstract: A new dc-dc converter with high voltage gain is proposed in this study. The proposed converter consists of two switches which are turned on and off simultaneously. Additionally, two Switched-Capacitor (SC) cells and one Energy Storage (ES) cell are utilized in the structure of the proposed converter. These result in high voltage gains at low values of the duty cycle. Besides, the voltage stress across the power devices is low and below half of the output voltage. Therefore, the MOSFET switches with low RDS-on and devices with reduced nominal voltage can be used in the proposed converter which in turn reduces the conduction and turn-on losses. The analysis of the voltage and current stresses of the devices is accomplished. The circuit performance is compared with other solutions in the literature in terms of voltage gain and normalized voltage stress of switches and diodes. Eventually, in order to verify the theoretical analysis, the experimental results are provided.

High step-up dc/dc converter using switch-capacitor techniques and lower losses for renewable energy applications

Abstract: In this study, a non-isolated high step-up direct current (dc)/dc converter with a diode-capacitor is presented. To obtain high-voltage gain, the voltage multiplier units (diode-capacitor) can be extended to n stages which are used between the phases in up section and down section of the proposed converter. By increasing the number of voltage multiplier units, the nominal value of the components decreases. Therefore, the maximum voltage value of diodes and power switches compared with the output voltage is decreased and finally, the normalised voltage of these devices will decrease, significantly. In addition, the power level of the proposed converter can be increased for different values of duty cycles and voltage multiplier units and also leads to high efficiency. To illustrate the advantages of the proposed converter, comparison results with other topologies are provided. The principle of operation at n = 1, 2 stages, both theoretical analysis and experimental results of two prototypes in 100 and 250 W with operating at 40 kHz are provided.

A Novel Multiphase High Step-Up DC/DC Boost Converter With Lower Losses on Semiconductors

Abstract: In this paper, a new multiphase interleaved dc/dc converter is presented. The proposed converter consists of two symmetric sections. Each section consists of several switches, inductors, diodes, and capacitors. In order to obtain high voltage gain, the proposed converter can be extended to n stages of voltage multiplier units which are used between the phases. Hence, the voltage gain of the proposed transformerless converter will be significantly high. In addition, the other advantage of the proposed converter not only contains lower voltage stress on the semiconductors but also leads to high efficiency for different values of duty cycles. The value of input current ripple is low due to using the interleaved technique. To illustrate the merits of the presented converter, comparison results with other converters are provided. The principle of operation in three-phase case, both theoretical analysis and experimental results of two prototype in different ranges with operating at 25 kHz are provided.

High step-up interleaved dc/dc converter with high efficiency

Abstract: In this paper, a new non-isolated Interleaved dc/dc converter with high-voltage conversion ratio is presented. The proposed converter combined with interleaved converter techniques and volt...

High Voltage Gain DC/DC Converter Using Coupled Inductor and VM Techniques

Abstract: In this study, a new non-isolated high voltage gains dc/dc converter using coupled inductor and voltage multiplier techniques (diode/capacitor) is presented The voltage gain will be increased by increasing the turns ratio (N) and the number of stages of the VM units The proposed converter capable to more increase the output voltage gains with transfer energy which is stored in coupled inductance Also, the voltage multiplier unit causes to further increase in the output voltage level of the proposed converter Besides, the nominal value of the semiconductors is low due to these are clamped to the capacitors available on the voltage multiplier units The normalized voltage stress across the semiconductors is low which this case is compared in the comparison section Therefore, the power loss of switch can be reduced by using a switch with a lower rating (lower RDS(on)) and power diodes with the low nominal rating As a result, the overall efficiency of the proposed converter will be high To confirm the benefits of working in this paper, comparison results for different items with other works are provided in section 4 The principle of operation, the theoretical analysis and the experimental results of a laboratory prototype for N(N2/N1) = 2 and n = 2 stage in about 260W with operating at 40kHz are provided

A New High Step-Up Multi-Input Multi-Output DC–DC Converter

Abstract: In this paper, a new multi-input multi-output (MIMO) dc–dc converter with high step-up capability is proposed for wide power ranges. Also, in order to increase each output voltage, diode–capacitor voltage multiplier (VM) stages are utilized in the proposed converter. The number of input stages, output stages, and VM stages are arbitrary and dependent on design conditions. At first, the general structure of proposed MIMO converter is presented. Then, in order to explain the converter operation, we walk through the design of a 1-kW four-input two-output example, including loss and efficiency calculations. We validate the design with a prototype that matches efficiency calculations.

A review of multiple input DC-DC converter topologies linked with hybrid electric vehicles and renewable energy systems

Abstract: In this paper, the contemporary development in multiple input dc-dc converters are identified and examined. The quest to mitigate the difficulties associated with employing renewables in distribution systems and electric vehicles (EVs) has yielded many new converter topologies. These new topologies have easier control, lower parts count, are cheaper and are worthy alternatives to the typical series or parallel connection of converters. The converters are identified by three divisions that bother on the isolation between the respective ports. The electrically connected converters do not have isolation between the ports, and thus, a dc link connects the ports. Electromagnetically connected converters use a dc-link to connect input ports, but the input ports and output port are isolated. In magnetically connected converters, input ports are separated by multiple winding transformer, just as the output port is isolated from the input ports by the winding. The formation, structure, characteristics, operation, merits and demerits of the converters will be presented. Thereafter, comparisons will be done based on the distinct features of the converters. This review identifies that converter properties depend on the specific application requirement and thus, no converter fulfills all demands in the industry. Prospective future research trends are suggested. This work aims to update on research done during the time gap since the last comprehensive reviews.

Single-Inductor Multi-Input Multi-Output DC–DC Converter With High Flexibility and Simple Control

Abstract: Multi-input multi-output (MIMO) dc–dc converters can integrate multiple input sources and output loads simultaneously. This article proposes a new single-inductor MIMO dc–dc converter with a wide conversion ratio. The proposed converter allows input sources to be added or removed seamlessly with no cross-regulation problem. Meanwhile, the outputs are independently controlled, i.e., the load change at one output cell will not affect the other interconnected output cells. Constant current control is the main control requirement. When constant current control is applied to all input cells, the power provided by each input source is proportional to the voltage magnitude of the source. When the constant current control is applied to some of the input cells, the input sources with direct duty-cycle controlled input cells can provide specific power through controlling the duty cycles of the switches of the corresponding input cells. Moreover, the switching time of switches is irrelevant. Therefore, it is easy to realize the high extension capability for arbitrary inputs/outputs. A dual-input dual-output prototype is constructed to illustrate the performance of the proposed converter. The corresponding component design is presented.