Loading...
Search for:
time-simulations
0.007 seconds
Total 28 records
A high performance real-time simulator for controllers hardware-in-the-loop testing
, Article Energies ; Volume 5, Issue 6 , 2012 , Pages 1713-1733 ; 19961073 (ISSN) ; Karimi, H ; Etemadi, A ; Iravani, R ; Sharif University of Technology
2012
Abstract
This paper presents a high performance real-time simulator for power electronic systems applications and primarily intended for controller hardware-in-the-loop (CHIL) testing. The novelty of the proposed simulator resides in the massively parallel hardware architecture that efficiently exploits fine-grained parallelism without imposing severe communication overhead time that can limit the performance. The simulator enables the use of a nanosecond range simulation timestep to simulate power electronic systems. Through the use of this nanosecond range simulation timestep, the simulator minimizes the error arising from the intersimulation timestep switching phenomenon associated with CHIL. The...
Analysis of Dynamic Behavior and Inter Area Oscillations Characteristics in the Iran Electrical Grid
, M.Sc. Thesis Sharif University of Technology ; Parniani, Mostafa (Supervisor)
Abstract
In this thesis, dynamic behavior of the Iran’s power grid has been analyzed and inter-area oscillations of this grid have been studied. Important results of this thesis are inter-area oscillation modes characteristics, regions and coherent generators and tie-lines in expose of high amplitude oscillations. These results could be used in different applications. It is time consuming and complicated to apply complete model for dynamic analyzing, therefore in most of researches an equivalent dynamic model should be prepared. First step for constructing this grid is identifying coherent generators. There are different methods to identify coherent ones, but it is not possible to apply all of them...
Transaint Simulation of Turbojet Engine With Hybrid Method
, M.Sc. Thesis Sharif University of Technology ; Ghorbanian, Kaveh (Supervisor)
Abstract
According to importance for modeling engine in propulsion subject and delecacies and complenity of this topic. Modeling turbofan engine has been chosen as the target of this project.Three methods are presented by this modeling and the results are compared. In addition, problems and shortcomings of each method are surveyed and stated. Surveying of each method is done step by step. In order to simplify description for any reader to reach the ultimate goal .In the beginning of the process, each coded method is stated full description .furthermore modeling process is illuminated. More ever, difference in methods is expressed. The results of three methods are processed and presented completely....
Design and Hardware Implementation of Real-Time Simulator for Electrical Machines
, M.Sc. Thesis Sharif University of Technology ; Hashemi, Matin (Supervisor) ; Parniani, Mostafa (Co-Advisor)
Abstract
Real-time simulators are important in design and test of power systems. Real-time simulators with hardware-in-loop capabilities are used in design of new elements in order to achieve maximum compatibility between subsystems, or in diagnosis and maintenance.The purpose of this dissertation is to design a real-time simulator for electrical machines. For this purpose, a three-phase induction machine is chosen and its model is extracted and discretized. This procedure results in a system of differential equations in form of AX = B. The extracted equations needs to be solved in real-time at every time-step. The real-time algorithms are imple-mented on FPGA. The implemented real-time simulator...
Real-time Simulation of Soft Tissue in Virtual Environments Using a Haptic Interface
, M.Sc. Thesis Sharif University of Technology ; Meghdari, Ali (Supervisor)
Abstract
Surgical simulators present a safe, practical, and ethical method for surgical training. In order to enhance realism and provide the user with an immersive training experience, simulators should have the capability to provide haptic feedback to the user. Accurate modeling of the interaction between surgical instruments and organs has been recognized as a key requirement in the development surgical simulators. Researchers have attempted to model tool-tissue interactions in a wide variety of ways, which can be broadly classified as (1) continuum mechanics-based,(2) discrete elements-based methods.
This thesis presents an improved model of static Long Elements Method (LEM), a new method...
This thesis presents an improved model of static Long Elements Method (LEM), a new method...
Coordinated Tuning of Power System Stabilizer in Iran Power Grid for Damping Local and InterArea Oscilation
, M.Sc. Thesis Sharif University of Technology ; Parniani, Mostafa (Supervisor)
Abstract
Power systems aredynamic and complex systems that are always subject to continuous changes and disturbance. Power system stability is a requirement for its satisfactory utilization. High speed Automatic voltage controllers with high gain tend to deteriorate both the electromechanical oscillation damping and small signal stability margin. Power system stabilizer (PSS) is a complementary controller that uses exciter voltage reference modulation to improve the electromechanical oscillation damping and stability margin. Optimal operation of PSS requires appropriate tuning according to the grid and power plant characteristics. In a largepower grid, absence or improper tuning of PSSs may cause one...
Planning a robust path for mobile robots in dynamic environment
, Article 2009 14th International CSI Computer Conference, CSICC 2009, 20 October 2009 through 21 October 2009, Tehran ; 2009 , Pages 470-476 ; 9781424442621 (ISBN) ; Manzuri Shalmani, M. T ; Sharif University of Technology
Abstract
In this paper, we propose a new method for mobile robot path planning in dynamic environment when the trajectories of obstacles are unknown. Our algorithm first utilizes a global approach called clearance based probabilistic roadmap method to find a suitable path and then locally apply evolutionary algorithm to keep the structure of the path when obstacles collide with the path. As a result, the path will act like an elastic band. To reach real time applicability, a light fitness function is proposed compare to other genetic algorithms to reduce the computation time needed for calculating and repairing path. Simulation results show that our method not only can keep the original structure of...
2D-Bert: Two dimensional burst error recovery technique
, Article 2007 15th International Conference on Software, Telecommunications and Computer Networks, SoftCOM 2007, Split - Dubrovnik, 27 September 2007 through 29 September 2007 ; 2007 , Pages 411-415 ; 9789536114931 (ISBN) ; Kialashaki, H ; Lakdashti, A ; Sharif University of Technology
2007
Abstract
Compressed images such as JPEG when transmitted over communication channels are susceptible to channel noise and/or erasure, which causes losses of blocks of pixels or macroblocks. Recovery of a large block in an image is a difficult task. In this paper we propose a novel method that addresses this problem and can exactly recover a lost block. Moreover, the proposed algorithm is fast enough to be implemented in real time. Simulation results show that our method is faster than previous methods proposed in the literature with less distortion
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) ; 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...
Design and Hardware Implementation of Real-Time Simulator for Power Electronic Systems
, M.Sc. Thesis Sharif University of Technology ; Hashemi, Matin (Supervisor) ; Parniani, Mostafa (Co-Advisor)
Abstract
Real-time simulators are playing a critical role in the design of power electronic systems. Using real-time simulator enables designers to reduce the time and cost of design by employing hardware-in-the-loop technique. In addition, this simulator can potentially reduce the risks which are associated with performing tests on actual systems. In this thesis, a real-time simulator is designed and implemented for power electronic applications. Concerning the fact that power switches are one of the most important elements in this simulator, an ideal switch model with conduction resistor and RC snubber circuit is used. This model is more accurate as compared to other models in the...
Design and Implementation Real-Time Simulator for CHB Converter using FPGA
, M.Sc. Thesis Sharif University of Technology ; Zolghadri, Mohammad Reza (Supervisor)
Abstract
With development of power electronic science and with the existence of different power electronic converters in this field, the need for improving their operation and the fault detection methods of these converters, the need for simulation and test of them is strong felt. However, experimental constrain such as damage risks, reliability, costs, and so on obviate the need for making the converter and the need for testing it and its controller. Accordingly, we do the testing on a special platform for Real-Time simulation.Control/protection platform needs to be tested and its functionality should be verified prior to installation and commissioning.Testing in theReal-Time simulator environment...
Design and Implementation of FPGA Based Real Time Simulator for Power Electronic Converters
, M.Sc. Thesis Sharif University of Technology ; Zolghadri, Mohammad Reza (Supervisor)
Abstract
Real-time Simulator plays an important role in the test of power electronic converters. Using of this simulators and Hardware-in-the-loop tests, cost and time of experiments will redused, furthermore those experiments which are not operative on the real system, can be achived. However, the accuracy of the used model in simulation as well as fast and easy programming of these simulators is very important. Therefore in this thesis, design and implementation of real-time simulator for power electronic converters have been discussed that in addition to high accuracy of the simulation, implementation of the several tests will be easy. As regards the power electronic switch is the most important...
Trading strategies for wind capacity investment in a dynamic model of combined tradable green certificate and electricity markets
, Article IET Generation, Transmission and Distribution ; Volume 6, Issue 4 , 2012 , Pages 320-330 ; 17518687 (ISSN) ; Hosseini, S. H ; Sharif University of Technology
2012
Abstract
In this study, a time simulation model for long-term wind capacity investment decisions in the presence of an electricity market and a tradable green certificate (TGC) market is proposed. Decisions related to the investments in the wind capacity are fundamentally based on incentives gained from both of these markets. Fundamental concepts and models of these markets are described. The TGC price trend-following and value-trading strategies for both generation and distribution companies and the regulatory policies for the limitation of TGC holding time and TGC borrowing fraction are included. In this study, a new dynamic model of coupled TGC and electricity markets is considered in order to...
Study of stochastic sequence-dependent flexible flow shop via developing a dispatching rule and a hybrid GA
, Article Engineering Applications of Artificial Intelligence ; 2012 , Pages 494-506 ; 09521976 (ISSN) ; Fatemi Ghomi, S. M. T ; Oroojlooy Jadid, A ; Sharif University of Technology
2012
Abstract
A flexible flow shop is a generalized flow shop with multiple machines in some stages. This system is fairly common in flexible manufacturing and in process industry. In most practical environments, scheduling is an ongoing reactive process where the presence of real time information continually forces reconsideration of pre-established schedules. This paper studies a flexible flow shop system considering non-deterministic and dynamic arrival of jobs and also sequence dependent setup times. The problem objective is to determine a schedule that minimizes average tardiness of jobs. Since the problem class is NP-hard, a novel dispatching rule and hybrid genetic algorithm have been developed to...
Modified wavefront decomposition method for fast and accurate ray-tracing simulation
, Article IET Microwaves, Antennas and Propagation ; Volume 6, Issue 3 , February , 2012 , Pages 295-304 ; 17518725 (ISSN) ; Shishegar, A. A ; Sharif University of Technology
Abstract
This study presents the modified wavefront decomposition method as a new ray-tracing acceleration technique for indoor propagation modelling. In this method, the exact propagation paths of the rays that reach the receiver after multiple reflections and/or refractions are calculated. Thus, the electromagnetic field at the receiver is obtained with a high accuracy. When only reflections are considered, our method simplifies to the multiple image theory or shooting and bouncing ray/image approach already available in the literature. However, the modified wavefront decomposition method calculates the exact propagation paths toward the receiver even if the rays encounter multiple refractions or a...
Partov: A network simulation and emulation tool
, Article Journal of Simulation ; Volume 10, Issue 4 , 2016 , Pages 237-250 ; 17477778 (ISSN) ; Kharrazi, M ; Sharif University of Technology
Palgrave Macmillan Ltd
Abstract
Network protocol design and evaluation requires either full implementation of the considered protocol and evaluation in a real network, or a simulation based on a model. There is also a middle approach in which both simulation and emulation are used to evaluate a protocol. In this article the Partov engine, which provides both simulation and emulation capabilities simultaneously, is presented. Partov benefits from a layered and platform-independent architecture. As a pure simulator, it provides an extensible plugin-based platform that can be configured to perform both real-time and non-real-time discrete-event simulations. It also acts as an emulator, making interaction with real networks...
Modeling nano-scale grain growth of intermetallics
, Article Bulletin of Materials Science ; Volume 32, Issue 1 , 2009 , Pages 19-21 ; 02504707 (ISSN) ; Sharif University of Technology
2009
Abstract
The Monte Carlo simulation is utilized to model the nano-scale grain growth of two nanocrystalline materials, Pd81Zr19 and RuAl. In this regard, the relationship between the real time and the time unit of simulation, i.e. Monte Carlo step (MCS), is determined. The results of modeling show that with increasing time of heating, the grain sizes of both nano-crystalline materials increased as in the case of conventional materials. Moreover, it is found that for both nano-crystalline materials the relationship between the real time and MCS is in power law form, which is linear for the conventional materials. © Indian Academy of Sciences
A Matrix-inversion technique for FPGA-based real-time EMT simulation of power converters
, Article IEEE Transactions on Industrial Electronics ; Volume 66, Issue 2 , 2019 , Pages 1224-1234 ; 02780046 (ISSN) ; Hashemi, M ; Labbaf, M ; Parniani, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
This paper proposes a novel FPGA-based matrix-inversion technique that is specifically tailored and optimized for real-time electromagnetic transients simulation of power electronic converters with high switching frequency. This is the first reported solution that is capable of solving the real-time equations related to using ideal switch model and the associated circuitry in very small time-steps (e.g., an average of 36 ns in a three-phase back-to-back converter case study), without requiring large amount of memory, being limited to small number of switches, adding parasitic elements, or depending on a priori knowledge of the circuit operation or switching strategy. The accuracy of the...
Real time simulation of grasping procedure of large internal organs during laparoscopic surgery
, Article Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS ; 2012 , Pages 924-927 ; 1557170X (ISSN) ; 9781424441198 (ISBN) ; Mirbagheri, A ; Farahmand, F ; Behzadipour, S ; Firoozbakhsh, K ; Sharif University of Technology
2012
Abstract
Surgical simulation systems facilitate safe and efficient training processes of surgical trainees by providing a virtual environment in which the surgical procedure can be repeated unlimitedly in a wide variety of situations. The present study attempted to develop a real time simulation system for the grasping procedure of large internal organs during laparoscopic surgery. A mass-spring-damper model was developed to simulate the nonlinear viscoelastic large deformations of the spleen tissue while interacting with a triple-jaw grasper. A novel collision detection algorithm was designed and implemented to determine the contact points between the tissue and the grasper jaws. Force or...
Simulation of red blood cell deformation in microvessels using a new rapid modified particle method
, Article ASME 2011 International Mechanical Engineering Congress and Exposition, IMECE 2011, 11 November 2011 through 17 November 2011 ; Volume 6, Issue PARTS A AND B , November , 2011 , Pages 1087-1090 ; 9780791854921 (ISBN) ; Ahmadian, M. T ; Hasanian, M ; Samiezadeh, S ; Sharif University of Technology
Abstract
The deformation of human red blood cell has been a topic of considerable scientific interest and real-life significance. Several methods have been improved to simulate the behavior of red blood cells motion and deformation in micro-capillaries. Since in microscopic scales, using discrete models are more preferred than continuum methods, moving particle semiimplicit method (MPS) which is one of the recent innovative particle based methods, can simulate micro-fluidic flows based on Navier-Stocks equations. It has been shown that original MPS method has a lack of rapid calculation which leads to massive calculations and long time simulation. Quite a few studies have been done to improve MPS...