Papers by Reza barzegarkhoo
IEEE Transactions on Power Electronics
Transformerless (TL) grid-connected photovoltaic (PV) inverters with a common-ground (CG) circuit... more Transformerless (TL) grid-connected photovoltaic (PV) inverters with a common-ground (CG) circuit architecture exhibit some excellent features in removing the leakage current concern and improving the overall efficiency. However, the ability to cope with a wide range of input voltage changes while maintaining the output voltage in a single power conversion stage is a key technological challenge. Considering this, the article at hand proposes a novel dual-mode switched-capacitor five-level (DMSC5L)-TL inverter with a CG feature connected to the grid. The proposed topology is comprised of a single dc source and power diode, three capacitors, four unidirectional, and three bidirectional power switches. Based on the series-parallel switching conversion of the involved switches, the proposed DMSC5L-TL inverter can generate five distinctive output voltage levels during both the boost and buck operation modes with a self-voltage balancing operation for the involved capacitors. A simple dead-beat continuous current controller (DB3C) modulation technique is also used to handle both the active and reactive power exchange while ensuring a fixed switching frequency operation. The proposed circuit description with its DB3C details, the design guidelines with a comparative study, and some experimental results are also given to show the feasibility of the proposed solution for the practical applications.
IEEE Journal of Emerging and Selected Topics in Power Electronics
2019 IEEE Energy Conversion Congress and Exposition (ECCE)
IEEE Transactions on Power Electronics
IEEE Transactions on Energy Conversion
IEEE Transactions on Industrial Electronics
IEEE Transactions on Industrial Electronics
IET Power Electronics
These days, Symmetric multilevel inverters (SMLIs) have become as one of the efficient solutions ... more These days, Symmetric multilevel inverters (SMLIs) have become as one of the efficient solutions to improve the output power quality of many renewable-energy based applications. To achieve better output power spectrum in the conventional types of SMLIs, as the number of output voltage levels increases, the number of required power switches and the overall cost will be enhanced. The aim of this study is to present a new cost effective SMLIs configuration, which can generate greater number of output voltage levels with a least of switching devices. The proposed structure contains a novel switched-dc-source (SDCS) sub-module that can produce three positive output voltage levels with a contribution of four equal dc voltage sources, two unidirectional, and one bi-directional power switches. Accordingly, to create a uniform staircase output voltage with multiple levels, the proposed SDCS sub-module is integrated into a new design. Therefore, a new family of reduced switch-count (RSC)-SMLIs is derived, which is capable of generating at least 13-and 15-level output voltages using only ten power switches and nine gate drivers. Furthermore, when employing several of the proposed SDCS sub-modules in series, a new generalized RSC-SMLI topology is obtained. Comparisons with prior-art SMLIs structures are done, which also highlights the beneficial potential of the proposed topology. To demonstrate the superior performance of the proposed topology, several simulation and experimental results have been provided.
IET Power Electronics
Nowadays, reduction in number of dc voltage sources alongside boosting property of the output vol... more Nowadays, reduction in number of dc voltage sources alongside boosting property of the output voltage with reduced circuit components are counted as the most important topological features for the new structures of multilevel voltage source inverters. Considering the above, this study presents a new configuration of such converters which can produce a step-up 19-level waveform of the output voltage with a contribution of only two same (symmetric) values of dc voltage sources and 12 power switches. The proposed structure is composed of a switched-capacitor (SC) and a floating-capacitor-based (FCB) cell integrated into two isolated sub-units that have been series with each other as an hybridised platform. Herein, the relevant involved switches of the SC and FCB sub-units are modulated on the basis of an hybridised pulse width modulation technique which facilitates a significant degradation in the total power loss dissipation. An appropriate boosting feature with a self-charge balancing capability of all integrated capacitors, reasonable number of required semiconductor devices, higher efficiency and less complexity are other advantages of the proposed step-up 19-level inverter. To verify the precise performance of the proposed topology under different types of loading conditions, apart from the theoretical analysis, several simulation and experimental results will also be presented.
IEEE Transactions on Power Electronics
—In this paper, a novel platform for the single phase switched-capacitor multilevel inverters (SC... more —In this paper, a novel platform for the single phase switched-capacitor multilevel inverters (SCMLIs) is presented. It has several advantages over the classical topologies, such as an appropriate boosting property, higher efficiency, lower number of required dc voltage sources, and other accompanying components with less complexity and lower cost. The basic structure of the proposed converter is capable of making nine-level of the output voltage under different kinds of loading conditions. Hereby, by using the same two capacitors paralleled to a single dc source, a switched-capacitor (SC) cell is made that contributes to boosting the value of the input voltage. In this case, the balanced voltage of the capacitors can be precisely provided on the basis of the series– parallel technique and the redundant switching states. Afterward, to reach the higher number of output voltage levels, two suggested SC cells are connected to each other with a new extended configuration. Therefore, by the use of a reasonable number of required power electronic devices, and also by utilizing only two isolated dc voltage sources, which their magnitudes can be designed based on either symmetric or asymmetric types, a 17-and 49-level of the output voltage are obtained. Based on the proposed extended configuration , a new generalized version of SCMLIs is also derived. To confirm the precise performance of the proposed topologies, apart from the theoretical analysis and a complete comparison, several simulation and experimental results are also given.
Nowadays, reduction in number of dc voltage sources alongside boosting property of the output vol... more Nowadays, reduction in number of dc voltage sources alongside boosting property of the output voltage with reduced circuit components are counted as the most important topological features for the new structures of multilevel voltage source inverters. Considering the above, this study presents a new configuration of such converters which can produce a step-up 19-level waveform of the output voltage with a contribution of only two same (symmetric) values of dc voltage sources and 12 power switches. The proposed structure is composed of a switched-capacitor (SC) and a floating-capacitor-based (FCB) cell integrated into two isolated sub-units that have been series with each other as an hybridised platform. Herein, the relevant involved switches of the SC and FCB sub-units are modulated on the basis of an hybridised pulse width modulation technique which facilitates a significant degradation in the total power loss dissipation. An appropriate boosting feature with a self-charge balancin...
IEEE Transactions on Power Electronics
Journal of Power Electronics
A high-step-up DC/DC converter for renewable energy systems is proposed. The proposed structure p... more A high-step-up DC/DC converter for renewable energy systems is proposed. The proposed structure provides high voltage gain by using a coupled inductor without the need for high duty cycles and high turn ratios. The voltage gain is increased through capacitor-charging techniques. In the proposed converter, the energy of the leakage inductors of the coupled inductor is reused. This feature reduces the stress on the switch. Therefore, a switch with low ON-state resistance can be used in the proposed converter to reduce losses and increase efficiency. The main switch is placed in series with the source. Therefore, the converter can control the energy flow from the source to the load. The operating principle is discussed in detail, and a steady state analysis of the proposed converter is conducted. The performance of the proposed converter is verified by experimental results.
2014 22nd Iranian Conference on Electrical Engineering (ICEE), 2014
Multilevel inverters due to adequate cost, simple implementation and high efficiency are very use... more Multilevel inverters due to adequate cost, simple implementation and high efficiency are very useful in modern drives and other medium and high power utilities. In this study, a new switched-capacitor multilevel inverter (SCMLI) topology is presented which can be used in high power applications with minimum count. Proposed SCMLI consists of several capacitors beside series/parallel power switches and diodes that can pass the reverse current for inductive loads. In this case, voltage of all capacitors is balanced by using proposed SPWM modulation technique with reduced ripple loss and good output waveform spectrum. Loss calculations and several simulation results by MATLAB/SIMULINK software are given to confirm the validity of proposed topology.
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Papers by Reza barzegarkhoo