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Circuit Printing for Low-Cost Electronics by Organic Inks
, M.Sc. Thesis Sharif University of Technology ; Sarvari, Reza (Supervisor)
Abstract
Due to the high cost of the conventional silicon-based circuits, printed electronic introduced as an ultra-low-cost saving techniques which are widely used in RFID tags, displays, sensors and thin film transistors and so on. Unlike the silicon-based devices, Organic materials are used in printed electronic devices, owing to this these devices can be used on large and flexible substrates like glass and plastic. Also in the printing method, there is no demand for expensive and time-consuming processes such as lithography or sputtering. Only by an ink-jet printer or graved cylinders the different layers of a device can be deposited. Besides these advantages of printed electronics to...
Design of a Tester for GOOSE Messages Performance Testing Defined in IEC 61850
, M.Sc. Thesis Sharif University of Technology ; Jahangir, Amir Hossein (Supervisor)
Abstract
Nowadays, electrical energy is a necessity and the use of intelligent power equipment is expanding. Of course, having a protocol for communicating between such equipment is not only useful but sometimes mandatory. In the past, each equipment manufacturer used its own method for communication, hence, the "IEC 61850" standard was proposed as a solution to solve the problem of communication between different equipment. In this research, we intend to design a tester to perform a performance test with for GOOSE messages. These messages are based on the IEC 61850 data set and have the ability to quickly and securely distribute input and output values at the system level, which are transmitted by a...
Rheological and sedimentation behaviour of nanosilver colloids for inkjet printing
, Article International Journal of Nanomanufacturing ; Volume 5, Issue 3-4 , 2010 , Pages 383-392 ; 17469392 (ISSN) ; Guenther, B. H ; Sharif University of Technology
2010
Abstract
Inkjet printing of colloidal metals is an attractive method for direct patterning of electrically conductive structures and interconnects in electronic devices, owing to low-cost, low-waste and simplicity of the process. In the present work, mixtures of well-dispersed silver nanoparticles and ethylene glycol were prepared for the inkjet printing process. Three different surfactants including PVP, MSA and AOT were added to study the stability of the nanosilver colloids. The effect of high-intensity ultrasonic treatment and temperature on the rheological properties was investigated utilising a rheometer in plate-plate geometry. It is shown that the viscosity of the ink increases with...
Residual flux mitigation of protective current transformers used in an autoreclosing scheme
, Article IEEE Transactions on Power Delivery ; Volume 31, Issue 4 , 2016 , Pages 1636-1644 ; 08858977 (ISSN) ; Salehizadeh, M ; Vakilian, M ; Sanaye Pasand, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
To avoid saturation of a protective current transformer (CT) operating under an autoreclosing scheme, the CT size should be chosen much higher than a similar CT operating under a single-step fault clearing scheme. The main reason for this significant difference is that the residual flux (caused by the first stage of the fault) cannot be noticeably reduced during the deadtime interval of the reclosing process and, therefore, the occurrence of a subsequent fault can extremely saturate the CT. In this paper, a low-cost, low-power electronic device is developed and introduced to demagnetize the CT under the reclosing deadtime interval. It will be shown that by using this device, the required...
Reliability evaluation of power grids considering integrity attacks against substation protective IEDs
, Article IEEE Transactions on Industrial Informatics ; Volume 16, Issue 2 , 2020 , Pages 1035-1044 ; Fotuhi Firuzabad, M ; Farzin, H ; Sharif University of Technology
IEEE Computer Society
2020
Abstract
Secure operation of protective intelligent electronic devices (IEDs) has been recognized as a crucial issue for power grids. By gaining access to substation IEDs, intruders can severely disrupt the operation of protection systems. This paper develops an analytical reliability assessment framework for quantifying the impacts of the hypothesized integrity attacks against protection systems. Petri net models are used to simulate possible intrusion scenarios into substation networks. The cyber network model is constructed from firewall, intrusion prevention system (IPS), and password models, which are three types of defense mechanisms for protecting substation networks. In this paper, two main...
Reliability assessment of some high side MOSFET drivers for buck converter
, Article 2013 3rd International Conference on Electric Power and Energy Conversion Systems, EPECS 2013, Istanbul ; 2013 ; 9781479906888 (ISBN) ; Kaboli, S ; Sharif University of Technology
2013
Abstract
Nowadays power electronic devices have a wide usage in the industries and different electrical equipment for power conditioning. As a point of view, reliability is one of important figure of merits that should be considered to have long life time and also have more probability to do exactly the proposed mission. In this paper some methods are presented to improve the reliability of power electronic components. Also some methods of system reliability improvement are reviewed. One group of converters is DC-DC step down converter which is used in different applications such as battery charger and voltage regulator. In this paper as an example, reliability of a DC-DC step down converter with...
Quantitative modeling and analysis of substation automation systems
, Article Proceedings of the IEEE Power Engineering Society Transmission and Distribution Conference ; 2012 ; 21608555 (ISSN) ; 9781467319348 (ISBN) ; Darabi, Z ; Fu, Y ; Vakilian, M ; Sharif University of Technology
2012
Abstract
The application of digital technologies in power systems has resulted in an evolutionary replacement of electromechanical devices with numerical ones featuring internal digital processors with communication capabilities. A substation automation system (SAS) deploys substation operation functions, including control, protection, monitoring, and measuring. Ethernet technology and local area networks (LANs) make it possible to design substation communication architectures with greater reliability, availability, speed, and cost savings than conventional hard-wired systems. This paper proposes a new method to describe topologies of the SAS as an interconnected network. The concept of data...
Programming of memristor crossbars by using genetic algorithm
, Article Procedia Computer Science, 6 October 2010 through 10 October 2010 ; Volume 3 , October , 2011 , Pages 232-237 ; 18770509 (ISSN) ; Shouraki, S. B ; Sharif University of Technology
2011
Abstract
Recently announcement of a physical realization of a fundamental circuit element called memristor by researchers at Hewlett Packard (HP) attracted so much interests and opened a new field in configurable or programmable electronic systems because it has properties of the perfect switch. Combination of this newly found circuit element with nanowire crossbar interconnect technology, creates a powerful platform which is called memristor crossbar. It has been demonstrated that this structure can offer the potential of creating configurable electronic devices which can have applications in signal processing and artificial intelligence. In this paper, we will highlight the rule that Genetic...
Modeling the detection efficiency in photodetectors with temperature-dependent mobility and carrier lifetime
, Article Superlattices and Microstructures ; Volume 122 , 2018 , Pages 557-562 ; 07496036 (ISSN) ; Ahmadpour, M ; Mosavi, A ; Alharbi, N ; Gorji, N. E ; Sharif University of Technology
Abstract
We proposed a modeling procedure to calculate the impact of temperature on the detection efficiency in photodetectors based on CdTe materials. Temperature increase impacts on the electrical properties of the materials such as carrier mobility and carrier recombination lifetime. This impact which can be effective in some cases has been normally ignored in the modeling approaches presented in the literature. Here we show that increasing the temperature from 190 K to 300 K not reduces the mobility of both electrons and holes but also significantly reduces the carrier lifetime. The result will impact on electric-field within the depletion width of the device, drift and diffusion lengths which...
Model-based Reliability-Centered design of power electronics dominated microgrids
, Article 17th International Conference on Probabilistic Methods Applied to Power Systems, PMAPS 2022, 12 June 2022 through 15 June 2022 ; 2022 ; 9781665412117 (ISBN) ; Blaabjerg, F ; Fotuhi Firuzabad, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
This paper proposes a model-based design approach for microgrids considering the aging of power electronic devices under different operating conditions. The proposed approach takes into account the physics of failure mechanisms in converter components as the failure prone devices in power systems. Furthermore, it considers the impacts of load profile on the aging of converter components and system performance. This approach facilitates accurate and optimized design of power electronic-based microgrids. According to this approach fragile links of power converters for a specified application can be identified. Moreover, the weakest converters based on their function in the microgrid can be...
Materials selection for electronic enclosures in space environment considering electromagnetic interference effect
, Article Advances in Space Research ; Volume 49, Issue 3 , February , 2012 , Pages 586-593 ; 02731177 (ISSN) ; Abedian, A ; Sharif University of Technology
2012
Abstract
Using low power electronic devices for space applications to reduce the mass and energy consumption has lead to electromagnetic interference (EMI) problem. Electronic enclosures are used to shield electronic devices against EMI. In the past, electromagnetic shielding has been mainly the only criteria considered in electronic enclosure design. However, there are several structural and thermal requirements for selection of shielding materials which should also be taken into account. In this research work, three quantitative materials selection methods, i.e. Digital Logic (DL), Modified Digital Logic (MDL), and Z-transformation, are employed to select the best material from among a list of...
Iterative machine learning-aided framework bridges between fatigue and creep damages in solder interconnections
, Article IEEE Transactions on Components, Packaging and Manufacturing Technology ; 2021 ; 21563950 (ISSN) ; Fotuhi Firuzabad, M ; Samavatian, M ; Dehghanian, P ; Blaabjerg, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
Costly and time-consuming approaches for solder joint lifetime estimation in electronic systems along with the limited availability and incoherency of data challenge the reliability considerations to be among the primary design criteria of electronic devices. In this paper, an iterative machine learning framework is designed to predict the useful lifetime of the solder joint using a set of self-healing data that reinforces the machine learning predictive model with thermal loading specifications, material properties, and geometry of the solder joint. The self-healing dataset is iteratively injected through a correlation-driven neural network to fulfill the data diversity. Outcomes show a...
Iterative machine learning-aided framework bridges between fatigue and creep damages in solder interconnections
, Article IEEE Transactions on Components, Packaging and Manufacturing Technology ; Volume 12, Issue 2 , 2022 , Pages 349-358 ; 21563950 (ISSN) ; Fotuhi Firuzabad, M ; Samavatian, M ; Dehghanian, P ; Blaabjerg, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
Costly and time-consuming approaches for solder joint lifetime estimation in electronic systems along with the limited availability and incoherency of data challenge the reliability considerations to be among the primary design criteria of electronic devices. In this article, an iterative machine learning framework is designed to predict the useful lifetime of the solder joint using a set of self-healing data that reinforce the machine learning predictive model with thermal loading specifications, material properties, and geometry of the solder joint. The self-healing dataset is iteratively injected through a correlation-driven neural network (CDNN) to fulfill the data diversity. Outcomes...
Influence of joint arrangement on the fracture behavior of lead-free solder joints
, Article Journal of Electronic Materials ; Volume 50, Issue 4 , 2021 , Pages 2117-2128 ; 03615235 (ISSN) ; Nourani, A ; Honarmand, M ; Assempour, A ; Sharif University of Technology
Springer
2021
Abstract
The capability to standardize the fracture strength of solder joints is an effective tool to investigate the reliability of electronic devices. To achieve this purpose, in this research, the influences of joint arrangement (loading arm and load sharing) on the level of constraint imposed on joint deformation, fracture energy, and generally, fracture behavior of solder joints were investigated. Fracture behavior of solder joints using double-cantilever-beam (DCB) specimens as a function of loading arm and load sharing (i.e., the distance between two solder joints) was studied under mode I loading conditions at a strain rate of 0.03 s−1. By increasing the loading arm, the fracture force, Fci,...
High-Performance fiber-shaped flexible asymmetric microsupercapacitor based on ni(oh)2 nanoparticles-decorated porous dendritic ni-cu film/cu wire and reduced graphene oxide/carbon fiber electrodes
, Article ACS Sustainable Chemistry and Engineering ; Volume 6, Issue 11 , 2018 , Pages 14574-14588 ; 21680485 (ISSN) ; Naderi, L ; Mohammadi, R ; Sharif University of Technology
American Chemical Society
2018
Abstract
Miniaturization of electronic devices with portable, flexible and wearable characteristics created a great demand for high-performance microscale energy storage devices with lightweight and flexible properties. Among the energy storage devices, wire-shaped supercapacitors (WSSCs) have recently received tremendous attention due to their tiny volume, wearability, high flexibility and potential applications in the next-generation portable/wearable electronic devices. Herein, we successfully fabricated a porous dendritic Ni-Cu film on Cu wire substrate (CWE) for fabrication of high-performance wire-type supercapacitors. The porous structure with dendritic morphology provides a high surface area,...
Guest editorial: special section on asset management in smart grid
, Article IEEE Transactions on Smart Grid ; Volume 6, Issue 2 , 2015 , Pages 953-954 ; 19493053 (ISSN) ; Khodaei, A ; Matevson, J ; Li, Z ; Bertling, L ; Passo, E. A ; Fotuhi Firuzabad, M ; Sharif University of Technology
Abstract
Electric power system and its components, most of which developed based on the rising electricity demand during economic growth periods of 1970s and 1980s, have aged and some are not being replaced quickly. In addition, the integration of variable sources of energy has changed the way assets are being managed for optimal operation. Aging assets and uncertainty in power system load profile and demand management create a challenge for the optimal operation and maintenance of the electricity grid. This special section aims at addressing the challenges and opportunities in deployment of smart grid technologies such as wireless sensors for condition monitoring and intelligent electronic devices...
Fabrication of a 2.8 V high-performance aqueous flexible fiber-shaped asymmetric micro-supercapacitor based on MnO2/PEDOT:PSS-reduced graphene oxide nanocomposite grown on carbon fiber electrode
, Article Journal of Materials Chemistry A ; Volume 8, Issue 37 , 2020 , Pages 19588-19602 ; Shahrokhian, S ; Soavi, F ; Sharif University of Technology
Royal Society of Chemistry
2020
Abstract
Flexible and lightweight fiber-shaped micro-supercapacitors have attracted tremendous attention as next-generation portable electronic devices, due to their high flexibility, tiny volume, and wearability. Herein, we successfully fabricated a ternary binder-free nanocomposite of MnO2/PEDOT:PSS-rGO on a carbon fiber substrate for application in high performance fiber-shaped micro-supercapacitors. The synergistic effects of the different components in the fiber-shaped electrode help to deliver a high specific capacitance of 2.9 F cm-2 (194 F cm-3 and 550 mF cm-1) at a current density of 5 mA cm-2 and a long cycle life with 95% capacitance retention after 5000 cycles in 1 M Na2SO4 electrolyte. A...
Effect of transverse and parallel magnetic fields on thermal and thermo-hydraulic performances of ferro-nanofluid flow in trapezoidal microchannel heat sink
, Article International Journal of Numerical Methods for Heat and Fluid Flow ; Volume 31, Issue 7 , 2021 , Pages 2089-2111 ; 09615539 (ISSN) ; Khorasanizadeh, H ; Shafii, M. B ; Sharif University of Technology
Emerald Group Holdings Ltd
2021
Abstract
Purpose: This paper aims to study the thermal and thermo-hydraulic performances of ferro-nanofluid flow in a three-dimensional trapezoidal microchannel heat sink (TMCHS) under uniform heat flux and magnetic fields. Design/methodology/approach: To investigate the effect of direction of Lorentz force the magnetic field has been applied: transversely in the x direction (Case I);transversely in the y direction (Case II); and parallel in the z direction (Case III). The three-dimensional governing equations with the associated boundary conditions for ferro-nanofluid flow and heat transfer have been solved by using an element-based finite volume method. The coupled algorithm has been used to solve...
ECG classification algorithm based on STDP and R-STDP neural networks for real-time monitoring on ultra low-power personal wearable devices
, Article IEEE Transactions on Biomedical Circuits and Systems ; Volume 13, Issue 6 , 2021 , Pages 1483-1493 ; 19324545 (ISSN) ; Hashemi, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
This paper presents a novel ECG classification algorithm for inclusion as part of real-time cardiac monitoring systems in ultra low-power wearable devices. The proposed solution is based on spiking neural networks which are the third generation of neural networks. In specific, we employ spike-timing dependent plasticity (STDP), and reward-modulated STDP (R-STDP), in which the model weights are trained according to the timings of spike signals, and reward or punishment signals. Experiments show that the proposed solution is suitable for real-time operation, achieves comparable accuracy with respect to previous methods, and more importantly, its energy consumption in real-time classification...
Current-Transformer saturation prevention using a controlled voltage-source compensator
, Article IEEE Transactions on Power Delivery ; Volume 32, Issue 2 , 2017 , Pages 1039-1048 ; 08858977 (ISSN) ; Vakilian, M ; Sanaye Pasand, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
Current-transformer (CT) saturation causes severe distortion in the measured current waveform which may lead to maloperation of the protective devices. This paper proposes a low-cost, power-electronic device to prevent the CT from saturation. The proposed compensator is inserted in series with the relay in the CT secondary circuit and acts as a controlled voltage source (CVS). The proposed CVS generates a time-varying voltage to cancel the voltage developed across the CT burden; therefore, the CT magnetic flux remains almost constant and undistorted during the power system transients. It will be shown that this device can precisely compensate fault current, inrush current, and other probable...