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    Modeling, control and voltage unbalance compensation in a four-switch rectifier with input power factor correction

    , Article PEDSTC 2013 - 4th Annual International Power Electronics, Drive Systems and Technologies Conference ; 2013 , Pages 148-152 ; 9781467344845 (ISBN) Ouni, S ; Shahbazi, M ; Zolghadri, M ; Sharif University of Technology
    2013
    Abstract
    In this paper, a small signal model is proposed for four-switch rectifier with input power factor correction. The required transfer functions are determined and calculated for a typical rectifier. This model is used to design an appropriate controller with defined characteristic to improve the rectifier performance. Another controller is used to compensate capacitors dc voltage difference. The system is simulated in Simulink and the results are provided. These results confirm the accuracy of the developed model, and also the effectiveness of the proposed controllers  

    Design and implementation of an FPGA-based real-time simulator for H-bridge converter

    , Article 7th Power Electronics, Drive Systems and Technologies Conference, PEDSTC 2016, 16 February 2016 through 18 February 2016 ; 2016 , Pages 504-510 ; 9781509003754 (ISBN) Rezaei Larijani, M ; Zolghadri, M. R ; Shahbazi, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2016
    Abstract
    This paper presents a methodology for implementing of the mathematical model of H-Bridge converter in an FPGA-based Real-Time simulator. Furthermore, it introduces a new method for choosing parameters of the Associate Discrete Circuit (ADC) model of semiconductor switches. The ADC-based model allows obtaining a fixed topology irrespective of switches states for the power electronic converters in the digital simulation. Backward-Euler based discretized state space matrix (SSM) of the circuit used for ADC parameter. Choosing appropriate switch parameter is based on 1) reducing the distance of SSM eigenvalues from origin in z-Plane to reduce settling-Time of system response; and 2) reducing the... 

    Control of a four-switch rectifier under unbalanced input voltage

    , Article PEDSTC 2014 - 5th Annual International Power Electronics, Drive Systems and Technologies Conference ; 2014 , p. 261-266 Ouni, S ; Javadian, V ; Shahbazi, M ; Zolghadri, M. R ; Sharif University of Technology
    Abstract
    Nowadays, reduced switch rectifiers are more interested because of less expense. Control of these rectifiers is an important part of their designing process. In this paper, a method is proposed for four-switch rectifier to continue working under unbalanced input voltage. To achieve this goal, first a method is introduced to separate positive and negative sequences of dq components. Also, the necessary condition is determined. Considering this condition, the control method is modified and new reference value for the control signals is calculated. Finally, the system is simulated in Simulink and the results are provided. These results confirm the accuracy of the developed model, and also the... 

    Fault tolerant operation of single-ended non-isolated DC-DC converters under open and short-circuit switch faults

    , Article 2013 15th European Conference on Power Electronics and Applications, EPE 2013 ; 2013 ; ISBN: 9781479901166 Jamshidpour, E ; Shahbazi, M ; Poure, P ; Gholipour, E ; Saadate, S ; Sharif University of Technology
    2013
    Abstract
    Fault tolerant operation of single-ended non-isolated DC-DC converters used in embedded and safety critical applications is mandatory to guaranty service continuity. This paper proposes a new, fast and efficient FPGA-based open and short-circuit switch fault diagnosis asssociated to fault tolerant converter topology. The results of Hardware-In-the-Loop and experimental tests are presented and discussed  

    A new fault tolerant scheme for cascaded H-Bridge multilevel converter

    , Article 2013 3rd International Conference on Electric Power and Energy Conversion Systems, EPECS 2013 ; 2013 ; 9781479906888 (ISBN) Ouni, S ; Noroozi, N ; Shahbazi, M ; Zolghadri, M ; Oraee, H ; Sharif University of Technology
    2013
    Abstract
    Multilevel converters are mainly used in high power applications (usually more than a few hundred kW). It is therefore important that they can continue working under faulty condition. In this paper, a new method is proposed to improve performance of CHB inverter under faulty condition. The proposed method will be compared with existing methods in term of voltage availability. The converter is simulated in Simulink and the results are provided. These results confirm the effectiveness of the proposed scheme, and are in accordance with the theoretical results  

    A new fault detection method for modular multilevel converter semiconductor power switches

    , Article 41st Annual Conference of the IEEE Industrial Electronics Society, 9 November 2015 through 12 November 2015 ; 2015 , Pages 50-55 ; 9781479917624 (ISBN) Haghnazari, S ; Shahbazi, M ; Zolghadri, M. R ; IEEE Industrial Electonics Society (IES) ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc 
    Abstract
    This paper proposes a new fault detection method for the modular multilevel converter (MMC) semiconductor power switches. While in common MMCs, the modules capacitor voltages are measured directly for control purposes, in this paper voltage measurement point changes to module output terminal improving fault diagnosis ability. Based on this measurement reconfiguration, a novel fault detection algorithm is designed for MMCs semiconductor power switches. The open circuit and short circuit faultsare detected based on unconformity between modules output voltage and switching signals. Simulations results confirm accurate and fast operation of the proposed algorithm in faulty module diagnosis.... 

    T-type direct AC/AC converter structure

    , Article IET Power Electronics ; Volume 9, Issue 7 , 2016 , Pages 1426-1436 ; 17554535 (ISSN) Khodabandeh, M ; Zolghadri, M. R ; Shahbazi, M ; Noroozi, N ; Sharif University of Technology
    Institution of Engineering and Technology  2016
    Abstract
    In this study, a novel T-type topology for single-phase direct AC/AC conversion is proposed. In this topology, frequency changing takes place directly (without common DC voltage bus) through three converters that are connected in a T structure. Unity input power factor and precise output voltage and frequency regulation is achieved through appropriate control of these three converters. H-bridge converters can be used in each branch of T to make the proposed converter. The converter is controlled such that the average active power of each H-bridge remains zero. Therefore, capacitors are implemented in DC links of H-bridges. Moreover, using half-bridge converters, instead of H-bridge ones, for... 

    Model identification of a Marine robot in presence of IMU-DVL misalignment using TUKF

    , Article Ocean Engineering ; Volume 206 , 2020 Ghanipoor, F ; Alasty, A ; Salarieh, H ; Hashemi, M ; Shahbazi, M ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    In today's world, control and navigation of autonomous underwater vehicles (AUVs) are quite challenging issues. In these fields, obtaining an identified dynamic model of AUV is a vital part. In this paper, a method for parameter estimation of an AUV planar model is proposed, which uses augmented state space technique and Square Root Transformed Unscented Kalman Filter (SR-TUKF) as an estimator. Furthermore, by modeling, misalignment between Inertial Measurement Unit (IMU) and Doppler Velocity Log (DVL) is estimated, simultaneously. Parameter identification is conducted using data of an AUV, equipped with Gyroscope, DVL and Encoder for measuring control inputs, in a planar maneuver. According... 

    Numerical analysis of 2D high speed flow of real gases on an adaptive unstructured grid

    , Article Iranian Journal of Science and Technology, Transaction B: Technology ; Volume 26, Issue 3 , 2002 , Pages 487-496 ; 03601307 (ISSN) Mazaheri, K ; Shahbazi, M. R ; Karimian, S. M. H ; Sharif University of Technology
    Shiraz University  2002
    Abstract
    The 2D hypersonic real gas flow has been analyzed on an adaptive unstructured grid using Roe's Flux Difference Splitting and AUSM schemes. In high temperature and hypersonic regime, the flow is extremely compressible and ideal gas assumption is not valid. In fact in these flows, due to changes in the flow properties, composition of fluid elements will also change. To solve steady and unsteady 2D Euler' equations for real gases, assumption of a general equation of state for real gases in equilibrium is considered. We use an unstructured Delaunay triangulation and adapt it in high gradient areas. Results are compared with known numerical and exact solutions. The scheme is convergent, and... 

    A fast and simple method to detect short circuit fault in cascaded H-bridge multilevel inverter

    , Article Proceedings of the IEEE International Conference on Industrial Technology, 17 March 2015 through 19 March 2015 ; Volume 2015-June, Issue June , 2015 , Pages 866-871 Ouni, S ; Rodriguez, J ; Shahbazi, M ; Zolghadri, M. R ; Schmeisser, U ; Oraee, H ; Lezana, P ; Ulloa Schmeisser, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2015
    Abstract
    Fault detection is one of the most important tasks in fault tolerant converters. In this paper, a new method is proposed to detect the faulty cell in a cascaded H-bridge multilevel inverter. The detection technique is based on comparison of the output voltage with reference voltage made by using switching control pulses and DC-Link voltage. Because of the simplicity of this method, it is possible to use a single field-programmable gate array (FPGA) to implement this method and inverter control. The simulation and experimental results confirm the effectiveness of the proposed fault detection technique  

    Quick diagnosis of short circuit faults in cascaded H-bridge multilevel inverters using FPGA

    , Article Journal of Power Electronics ; Volume 17, Issue 1 , 2017 , Pages 56-66 ; 15982092 (ISSN) Ouni, S ; Zolghadri, M. R ; Rodriguez, J ; Shahbazi, M ; Oraee, H ; Lezana, P ; Schmeisser, A. U ; Sharif University of Technology
    Korean Institute of Power Electronics  2017
    Abstract
    Fast and accurate fault detection is the primary step and one of the most important tasks in fault tolerant converters. In this paper, a fast and simple method is proposed to detect and diagnosis the faulty cell in a cascaded H-bridge multilevel inverter under a short circuit fault. In this method, the reference voltage is calculated using switching control pulses and DC-Link voltages. The comparison result of the output voltage and the reference voltage is used in conjunction with active cell pulses to detect the faulty cell. To achieve this goal, the cell which is active when the Fault signal turns to “0” is detected as the faulty cell. Furthermore, consideration of generating the active... 

    Silica nanoparticle surface chemistry: An important trait affecting cellular biocompatibility in two and three dimensional culture systems

    , Article Colloids and Surfaces B: Biointerfaces ; Volume 182 , 2019 ; 09277765 (ISSN) Hasany, M ; Taebnia, N ; Yaghmaei, S ; Shahbazi, M. A ; Mehrali, M ; Dolatshahi Pirouz, A ; Arpanaei, A ; Sharif University of Technology
    Elsevier B.V  2019
    Abstract
    Great advantages bestowed by mesoporous silica nanoparticles (MSNs) including high surface area, tailorable pore diameter and surface chemistry, and large pore volume render them as efficient tools in biomedical applications. Herein, MSNs with different surface chemistries were synthesized and investigated in terms of biocompatibility and their impact on the morphology of bone marrow-derived mesenchymal stem cells both in 2D and 3D culture systems. Bare MSNs (BMSNs) were synthesized by template removing method using tetraethylorthosilicate (TEOS) as a precursor. The as-prepared BMSNs were then used to prepare amine-functionalized (AMSNs), carboxyl-functionalized (CMSNs) and polymeric... 

    Improvement of post-fault performance of a cascaded h-bridge multilevel inverter

    , Article IEEE Transactions on Industrial Electronics ; Volume 64, Issue 4 , 2017 , Pages 2779-2788 ; 02780046 (ISSN) Ouni, S ; Zolghadri, M. R ; Khodabandeh, M ; Shahbazi, M ; Rodríguez, J ; Oraee, H ; Lezana, P ; Schmeisser, A. U ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2017
    Abstract
    This paper is focused on improving the post-fault performance of cascaded H-bridge multilevel inverters by decreasing the common-mode voltage. First, an algorithm is proposed to determine the optimal post-fault state among all possible states, which have the same maximum available voltage. Furthermore, a modified technique is proposed to calculate the references of inverter phase voltages under faulty conditions. This technique leads to a decrease in the common-mode voltage when the required output voltage is less than its maximum value. These solutions are mutually employed in the post-fault control system. Simulation and experimental results confirm the effectiveness of the proposed... 

    A hydrogen-bonded extracellular matrix-mimicking bactericidal hydrogel with radical scavenging and hemostatic function for ph-responsive wound healing acceleration

    , Article Advanced Healthcare Materials ; 2020 Ahmadian, Z ; Correia, A ; Hasany, M ; Figueiredo, P ; Dobakhti, F ; Eskandari, M. R ; Hosseini, H ; Abiri, R ; Khorshid, S ; Hirvonen, J ; Santos, H. A ; Shahbazi, M. A ; Sharif University of Technology
    Wiley-VCH Verlag  2020
    Abstract
    Generation of reactive oxygen species, delayed blood clotting, prolonged inflammation, bacterial infection, and slow cell proliferation are the main challenges of effective wound repair. Herein, a multifunctional extracellular matrix-mimicking hydrogel is fabricated through abundant hydrogen bonding among the functional groups of gelatin and tannic acid (TA) as a green chemistry approach. The hydrogel shows adjustable physicochemical properties by altering the concentration of TA and it represents high safety features both in vitro and in vivo on fibroblasts, red blood cells, and mice organs. In addition to the merit of facile encapsulation of cell proliferation-inducing hydrophilic drugs,... 

    A hydrogen-bonded extracellular matrix-mimicking bactericidal hydrogel with radical scavenging and hemostatic function for ph-responsive wound healing acceleration

    , Article Advanced Healthcare Materials ; Volume 10, Issue 3 , 2021 ; 21922640 (ISSN) Ahmadian, Z ; Correia, A ; Hasany, M ; Figueiredo, P ; Dobakhti, F ; Eskandari, M. R ; Hosseini, S.H ; Abiri, R ; Khorshid, S ; Hirvonen, J ; Santos, H. A ; Shahbazi, M. A ; Sharif University of Technology
    Wiley-VCH Verlag  2021
    Abstract
    Generation of reactive oxygen species, delayed blood clotting, prolonged inflammation, bacterial infection, and slow cell proliferation are the main challenges of effective wound repair. Herein, a multifunctional extracellular matrix-mimicking hydrogel is fabricated through abundant hydrogen bonding among the functional groups of gelatin and tannic acid (TA) as a green chemistry approach. The hydrogel shows adjustable physicochemical properties by altering the concentration of TA and it represents high safety features both in vitro and in vivo on fibroblasts, red blood cells, and mice organs. In addition to the merit of facile encapsulation of cell proliferation-inducing hydrophilic drugs,... 

    A hydrogen-bonded extracellular matrix-mimicking bactericidal hydrogel with radical scavenging and hemostatic function for ph-responsive wound healing acceleration

    , Article Advanced Healthcare Materials ; Volume 10, Issue 3 , 2021 ; 21922640 (ISSN) Ahmadian, Z ; Correia, A ; Hasany, M ; Figueiredo, P ; Dobakhti, F ; Eskandari, M. R ; Hosseini, S. H ; Abiri, R ; Khorshid, S ; Hirvonen, J ; Santos, H. A ; Shahbazi, M. A ; Sharif University of Technology
    Wiley-VCH Verlag  2021
    Abstract
    Generation of reactive oxygen species, delayed blood clotting, prolonged inflammation, bacterial infection, and slow cell proliferation are the main challenges of effective wound repair. Herein, a multifunctional extracellular matrix-mimicking hydrogel is fabricated through abundant hydrogen bonding among the functional groups of gelatin and tannic acid (TA) as a green chemistry approach. The hydrogel shows adjustable physicochemical properties by altering the concentration of TA and it represents high safety features both in vitro and in vivo on fibroblasts, red blood cells, and mice organs. In addition to the merit of facile encapsulation of cell proliferation-inducing hydrophilic drugs,... 

    Combinatorial screening of nanoclay-reinforced hydrogels: a glimpse of the "holy grail" in orthopedic stem cell therapy?

    , Article ACS Applied Materials and Interfaces ; Volume 10, Issue 41 , 2018 , Pages 34924-34941 ; 19448244 (ISSN) Hasany, M ; Thakur, A ; Taebnia, N ; Kadumudi, F. B ; Shahbazi, M. A ; Pierchala, M. K ; Mohanty, S ; Orive, G ; Andresen, T. L ; Foldager, C. B ; Yaghmaei, S ; Arpanaei, A ; Gaharwar, A. K ; Mehrali, M ; Dolatshahi Pirouz, A ; Sharif University of Technology
    American Chemical Society  2018
    Abstract
    Despite the promise of hydrogel-based stem cell therapies in orthopedics, a significant need still exists for the development of injectable microenvironments capable of utilizing the regenerative potential of donor cells. Indeed, the quest for biomaterials that can direct stem cells into bone without the need of external factors has been the "Holy Grail" in orthopedic stem cell therapy for decades. To address this challenge, we have utilized a combinatorial approach to screen over 63 nanoengineered hydrogels made from alginate, hyaluronic acid, and two-dimensional nanoclays. Out of these combinations, we have identified a biomaterial that can promote osteogenesis in the absence of...