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short-circuit-fault
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Reducing the Flow Rate of Short Circuit Fault Current at the Output of the High Voltage Power Supply
, M.Sc. Thesis Sharif University of Technology ; Kaboli, Shahriar (Supervisor)
Abstract
In this research, we have presented a method to delay the propagation of fault current in high voltage power supplies. Common protection methods usually protect the load and do not protect the power supply itself well. In this research, our goal was to propose a method to prevent the short circuit fault current from reaching the power supply elements. At first, the available methods to limit the fault current and protect the high voltage power sources were studied and investigated. Then, using the transmission line theory, a ladder filter was designed as an alternative to the normal filter at the output of the power supply. In the next step, using software simulation, the performance of the...
Stability Improvement and Protection of Grid-following Bidirectional Three-phase Voltage-sourced Converters under Unbalanced Grid Conditions
, M.Sc. Thesis Sharif University of Technology ; Mokhtari, Hossein (Supervisor) ; Karimi, Houshang (Co-Supervisor)
Abstract
With the increasing expansion of modern DC loads and utilizing energy storage systems along with distributed renewable energy resources, grid-following bidirectional voltage-sourced converters (GFBVSCs) with fast dynamic performance are required. Due to the presence of single-phase loads and asymmetrical short circuit faults, unbalanced grid voltage conditions are available in the distribution system. Under unbalanced conditions, an oscillating component with a frequency of twice the grid angular frequency appears on the DC side. Removing double-frequency ripple in the DC link voltage without third harmonic current injection and reactive power injection to the grid based on the grid codes to...
Improvement of Inverter-based AC Microgrids Protection Against Short Circuit
, Ph.D. Dissertation Sharif University of Technology ; Mokhtari, Hossein (Supervisor) ; Blaabjerg, Frede (Co-Supervisor)
Abstract
Inverter-based distributed generations (IBDGs) have gained special interest in the electricity supply chain due to the advancements in power electronics technology. Power electronic inverters provide high-efficiency energy conversion with full controllability over a wide operating range, and ancillary services such as reactive power support and active filtering. Considering the voltage and frequency control capability of power inverters, supplying inverter-based micro-grid (IBMG) loads is now pissible. Despite the significant opportunities associated with such sources, they introduce new challenges that should be addressed properly. Reliable and accurate protection against short circuit...
Fast short circuit power switch fault detection in cascaded H-bridge multilevel converter
, Article IEEE Power and Energy Society General Meeting ; 2013 ; 19449925 (ISSN); 9781479913039 (ISBN) ; Zolghadri, M. R ; Poure, P ; Saadate, S ; Sharif University of Technology
2013
Abstract
Multilevel converters are being widely used in a large number of power electronics applications. Due to the increased number of switching devices, they are more likely to have faults in their switches than the conventional converters. In order to have a balanced operation after a short circuit power switch fault occurrence, it is necessary to detect the fault location. In this paper, a fast power switch fault detection method is presented to identify the fault location. This method only needs one additional voltage sensor per phase, and is faster compared to most of the existing methods. Also it is easy for implementation on a FPGA chip. The proposed method is verified by computer...
Fault analysis on AC railway supply system
, Article 6th Annual International Power Electronics, Drive Systems, and Technologies Conference, PEDSTC 2015, 3 February 2015 through 4 February 2015 ; February , 2015 , Pages 567-572 ; 9781479976539 (ISBN) ; Mokhtari, H ; Zolghadri, M. R ; Khodabandeh, M ; Abazai, A ; Seyyedi Khakshani, R ; Mazaheri, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
A short circuit fault in an AC railway supply system could have undesired consequences; including high-amplitude current flow in the power path, the rail potential rise in the fault vicinity. This paper studies the problem of the rail voltage rise in Tehran-Karaj railway system by the use of a steady state circuit model for the AC autotransformer during a phase-to-ground fault. By using this model, all the currents and voltages of the system can be easily calculated for all possible short circuit fault locations. With the help of the derived analytical model, one can also predict the possible fault locations which may cause the protection system to operate. The estimation of the system...
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 ; 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
Fast fault detection method for modular multilevel converter semiconductor power switches
, Article IET Power Electronics ; Volume 9, Issue 2 , 2016 , Pages 165-174 ; 17554535 (ISSN) ; Khodabandeh, M ; Zolghadri, M. R ; Sharif University of Technology
Institution of Engineering and Technology
2016
Abstract
This study proposes a new fault detection method for modular multilevel converter (MMC) semiconductor power switches. While in common MMCs, the cells capacitor voltages are measured directly for control purposes, in this study voltage measurement point changes to the cell 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 faults are detected based on unconformity between modules output voltage and switching signals. Simulation and experimental results confirm accurate and fast operation of the proposed method in faulty cell...
Short-circuit analysis in three-phase quasi-Z-source inverter
, Article 17th IEEE International Conference on Environment and Electrical Engineering and 2017 1st IEEE Industrial and Commercial Power Systems Europe, EEEIC / I and CPS Europe 2017, 6 June 2017 through 9 June 2017 ; 2017 ; 9781538639160 (ISBN) ; Moghani, J. S ; Noroozi, N ; Zolghadri, M. R ; IEEE EMC Society; IEEE Industry Applications Society (IAS); IEEE Power and Energy Society (PES) ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
In this paper, the short-circuit fault in three-phase quasi-Z-source inverter (q-ZSI) is analyzed and a linear model is proposed for the short-circuit analysis. The proposed model is based on the state space equations of the system. By using this model, the most critical situation during short-circuit fault is recognized; the maximum reaction time for the protection system could be estimated and elements that are prone to failure are identified as well. The analysis is categorized into two groups, leg fault and switch fault. The linear model is confirmed by simulation of 1kw three-phase q-ZSI. © 2017 IEEE
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) ; 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...
Reinforcing fault ride through capability of grid forming voltage source converters using an enhanced voltage control scheme
, Article IEEE Transactions on Power Delivery ; 2018 ; 08858977 (ISSN) ; Mokhtari, H ; Ghasemi, M. A ; Blaabjerg, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
Medium power distributed energy resources (DERs) are commonly connected to medium voltage distribution systems via voltage source converters (VSCs). Several guidelines and standards have been developed to establish the needed criteria and requirements for DERs interconnections. In this respect, it is preferred to reinforce the VSC fault ride through (FRT) capability, which considerably minimizes the DG outage period and reconnection time and results in a resilient system against short circuits. Considering the significant number of asymmetrical faults in distribution systems, the VSC response in such conditions must be investigated, and consequently, its FRT capability must be reinforced. In...
A series stacked IGBT switch based on a concentrated clamp mode snubber for pulsed power applications
, Article IEEE Transactions on Power Electronics ; Volume 34, Issue 10 , 2019 , Pages 9573-9584 ; 08858993 (ISSN) ; Mohsenzade, S ; Kaboli, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Clamp mode snubbers are very well suited for the series structure of the insulated-gate bipolar transistors (IGBTs) in pulsed power applications. They properly meet the necessities expected from them such as the fast operating of the series IGBTs since they have no effect on the gate side. In addition, they can provide safe voltage condition for the IGBTs in short circuit faults, which are very probable in pulsed applications. The clamp mode snubber can perform its voltage balancing task whenever the power capacity of the snubber can support the injected powers due to the voltage unbalancing factors. This paper initially introduces the main factors injecting power to the snubbers. Then, it...
Reinforcing fault ride through capability of grid forming voltage source converters using an enhanced voltage control scheme
, Article IEEE Transactions on Power Delivery ; Volume 34, Issue 5 , 2019 , Pages 1827-1842 ; 08858977 (ISSN) ; Mokhtari, H ; Ghasemi, M. A ; Blaabjerg, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Medium power distributed energy resources (DERs) are commonly connected to medium voltage distribution systems via voltage source converters (VSCs). Several guidelines and standards have been developed to establish the needed criteria and requirements for DERs interconnections. In this respect, it is preferred to reinforce the VSC fault ride through (FRT) capability, which considerably minimizes the DG outage period and reconnection time and results in a resilient system against short circuits. Considering the significant number of asymmetrical faults in distribution systems, the VSC response in such conditions must be investigated, and consequently, its FRT capability must be reinforced. In...
A robust short-circuit fault diagnosis for high voltage DC power supply based on multisensor data fusion
, Article 10th International Power Electronics, Drive Systems and Technologies Conference, PEDSTC 2019, 12 February 2019 through 14 February 2019 ; 2019 , Pages 659-664 ; 9781538692547 (ISBN) ; Kaboli, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Short-circuit fault (SCF) detection is mandatory in a high voltage DC power supply (HVPS) to prevent fatal damage. The majority of converters employ a single sensor to detect the SCF. This attribute increases the interference vulnerability of the fault detection (FD) system in the presence of noise. Therefore, miss detections and false alarms are possible to occur. Miss detections and false alarms are harmful catastrophes in most applications. A commonly used method to suppress the noise impacts is using a low-bandwidth low-pass filter. However, the use of the low-bandwidth low-pass filter reduces the speed of FD due to the filter delay. This paper proposes a fast FD algorithm based on...
Proposal of an analytical model for performance evaluation of WR -resolvers under short circuit fault
, Article 27th Iranian Conference on Electrical Engineering, ICEE 2019, 30 April 2019 through 2 May 2019 ; 2019 , Pages 486-490 ; 9781728115085 (ISBN) ; Nasiri Gheidari, Z ; Tootoonchian, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Wound-Rotor (WR) resolvers are the most widely used position sensors in applications with harsh environmental conditions. However, their performance is exposed to failure due to high risk of short circuit (SC) fault. Although the output current of the resolver is negligible, its thin copper wires increases the probability of the short circuit fault. To avoid the propagation of the turn-to turn SC fault to the whole coil and undesirable performance of the motion control drive, it is necessary to diagnose it at the very beginning of its development. Meanwhile, the first step of diagnosing faults is their modeling. Time stepping finite element analysis is the most accurate, but computationally...
A Fast vacuum arc detection method based on the neural network data fusion algorithm for the high-voltage dc power supply of vacuum tubes
, Article IEEE Transactions on Plasma Science ; 2020 ; Kaboli, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
Vacuum arc is one of the most important failure factors of the vacuum tubes. The amount of delivered energy from the high-voltage dc power supply to the vacuum tube is an important issue during the vacuum arc in the tube. Vacuum arc acts as a short-circuit fault (SCF) at the power supply output. The majority of converters use a single current sensor to measure only the converter output current for detecting the SCF. However, the sensor may provide unreliable data because of the noise effect. Application of a low-pass filter reduces the noise effect. Regarding the delay of the low-pass filter, the interval of arc detection increases and more energy is delivered to the tube. In this article, a...
Detecting the location of short-circuit faults in active distribution network using pmu-based state estimation
, Article IEEE Transactions on Smart Grid ; Volume 11, Issue 2 , 2020 , Pages 1396-1406 ; Abbaspour, A ; Moeini Aghtaie, M ; Fotuhi Firuzabad, M ; Lehtonen, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
With the rapid advancement of phasor measurement units (PMUs) technology, system operators in different level of power systems have access to new and abundant measurements. Taking into account these measurements in active distribution systems (ADNs), a new algorithm for short-circuit fault detection and identification based on state estimation (SE) is introduced in this paper. In this regard, as the first step, traditional SE process is revised to be compatible with fault conditions. Then, a fault location algorithm (FLA) based on the revised SE (RDSSE) is presented which attends to detect the location of fault after diagnosing faulted zone. For this purpose, current and voltage...
A comprehensive analysis of short-circuit fault in wound-rotor resolvers
, Article IEEE Transactions on Vehicular Technology ; Volume 69, Issue 12 , December , 2020 , Pages 14884 - 14892 ; Nasiri Gheidari, Z ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
This paper presents a detailed analysis of short circuit fault (SCF) in wound rotor (WR) resolvers. For this purpose, an analytical model based on winding function (WF) method is developed considering the stator and rotor windings fault, the severity of the fault, the phase of the stator faulty winding, and the tooth of shorted turns. The proposed model leads to a comprehensive understanding of the SCF behavior of WR resolvers and also leads to define proper fault detecting signatures. All the predictions are verified by time stepping finite element analysis as well as the experimental tests on two prototyped resolvers. IEEE
Improving the accuracy of wound-rotor resolvers under inter-turn short circuit faults
, Article IEEE Sensors Journal ; Volume 21, Issue 5 , November , 2020 , Pages: 5944 - 5951 ; Tootoonchian, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
The performance of the resolver as a position sensor is significantly influenced by electrical and mechanical faults. Among different faults, short circuit in the stator windings has more destructive effect than others on accuracy of resolver. Furthermore, due to thin wires of the stator it is highly likely to occur. Therefore, in this paper a robust design is proposed for wound-rotor resolvers to not only suppress the influence of short circuit fault in the stator/rotor winding, but also improve the accuracy of the sensor under mechanical faults. The effectiveness of the proposed robust design is demonstrated by an analytical model based on winding function method and then approved by time...
Comprehensive analytics for reliability evaluation of conventional isolated multiswitch PWM DC-DC converters
, Article IEEE Transactions on Power Electronics ; Volume 35, Issue 5 , 2020 , Pages 5254-5266 ; Panahandeh Esmaeelnia, F ; Fotuhi Firuzabad, M ; Tahami, F ; Tohidi, S ; Dehghanian, P ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
This article offers a holistic model and approach on reliability assessment of conventional isolated multiswitch pulsewidth modulation dc-dc (IMSDC-DC) power electronic converters with conventional half-bridge, full-bridge, and push-pull dc-dc topologies. The proposed reliability assessment analytics encapsulate correlated effects of several conditions (e.g., open- and short-circuit faults) and prevailing parameters (e.g., duty cycle, input voltage, output power, transformer turns ratio, voltage gain, switching frequency, operation time duration, and components characteristics) on the overall reliability performance of IMSDC-DC converters. Such insights are then harnessed within a Markov...
Control of grid-following inverters under unbalanced grid conditions
, Article IEEE Transactions on Energy Conversion ; Volume 35, Issue 1 , 2020 , Pages 184-192 ; Mokhtari, H ; Ghasemi, M. A ; Peyghami, S ; Davari, P ; Blaabjerg, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
This paper proposes a new control scheme to eliminate the 3rd harmonic in the output currents of grid-following inverters under unbalanced grid conditions. Unbalanced grids adversely affect the performance of grid-following inverters due to the oscillations appearing on the DC-link voltage with a frequency twice the line frequency. The paper is based on instantaneous active reactive control (IARC) technique due to its advantages over other existing methods. However, the presence of severe asymmetrical 3rd harmonic distortions in the inverter output currents is the main challenge with IARC method, which impairs the power quality requirements. This paper enhances the IARC scheme by proposing a...