Ehsan Esfandiari
Volume 6, Issue 2 , June 2012
Abstract
A new configuration for a diode-clamped multi-level inverter based on a multi-winding transformer was proposed and simulated. The most important difference between this proposed DC-AC-AC structure and the basic structure is that; in the proposed structure, the back-to-back connected outputs of a multi-winding ...
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A new configuration for a diode-clamped multi-level inverter based on a multi-winding transformer was proposed and simulated. The most important difference between this proposed DC-AC-AC structure and the basic structure is that; in the proposed structure, the back-to-back connected outputs of a multi-winding transformer supersede the capacitors in the basic structure. The proposed structure provides the equilibrium in the total time of drawing power between the voltage source steps, as a result, decreasing the unbalancing effect. Isolation and capability to produce more output steps are other advantages of the proposed schematic compared with the conventional capacitor based diode-clamped structure. The simulation result shows the ability of this inverter to feed inductive loads.
Mohsen Siami; S. Asghar Gholamian
Volume 6, Issue 2 , June 2012
Abstract
This paper presents a predictive strategy to control torque and flux of an axial flux permanent magnet (AFPM) machine. Unlike conventional direct torque control (DTC) for permanent magnet machines that only six actives voltage vectors of inverter are used to control the torque and flux of the machine, ...
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This paper presents a predictive strategy to control torque and flux of an axial flux permanent magnet (AFPM) machine. Unlike conventional direct torque control (DTC) for permanent magnet machines that only six actives voltage vectors of inverter are used to control the torque and flux of the machine, in predictive torque control (PTC), zero voltage vectors are used to control too. Thus, the number of voltage vectors to control AFPM increases that leads to faster dynamic torque response and lower ripples of torque and flux. In predictive torque control presented in this paper, responses of torque and flux are computed for all possible switching states of the inverter at every sample time according to the discrete time model of the machine and then the switching state that optimizes ripples of torque and flux will be applied in next discrete-time interval. Simulation results which confirm the good performance of the proposed predictive torque control are presented.
Mahdi Bejani; Davood Gharavian; Nasrollah Charkari
Volume 6, Issue 2 , June 2012
Abstract
To make human–computer interaction (HCI) more natural and friendly, it would be beneficial to give computers the ability to recognize situations the same way a human does. Naturally, people use a spontaneous combination of face, body gesture and speech to express their feelings. In this paper we simulate ...
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To make human–computer interaction (HCI) more natural and friendly, it would be beneficial to give computers the ability to recognize situations the same way a human does. Naturally, people use a spontaneous combination of face, body gesture and speech to express their feelings. In this paper we simulate human perception of emotion with emotion related information from facial expression. Facial expression recognition based upon ITMI and QIM which can be seen as an extension to temporal templates. The system was tested on two different databases, the eNterface‘05 and the Cohn-Kanade face database and the recognition accuracy of our systems ,71.8 % on Cohn-Kanade and 39.27% on eNterface’05, compared to the published results in the literature.
Mohd Shahrieel Mohd Aras; Shahrum Shah Abdullah; Siti Saudah Shafei; M.Z.A Rashid; A. Jamali
Volume 6, Issue 2 , June 2012
Abstract
This paper presents the investigation and evaluation of low cost depth sensor system design for unmanned underwater vehicle (UUV) using pressure sensor. Two types of low cost pressure sensor system design are proposed for underwater vehicle. The pressure sensors are expected to prevent buckling or ...
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This paper presents the investigation and evaluation of low cost depth sensor system design for unmanned underwater vehicle (UUV) using pressure sensor. Two types of low cost pressure sensor system design are proposed for underwater vehicle. The pressure sensors are expected to prevent buckling or damaging to the UUV. The first design uses barometric pressure sensor, while the second design uses MPXAP which is an integrated silicon pressure sensor on-chip signal conditioned and temperature compensated. There are two different sub model of MPXAP put forward in this research namely, MPX4250AP and MPX5700AP. These pressure sensors are tested in three different conditions: in water tank, lake and swimming pool to study their effect on various densities. Details of the designs are discussed and implementations of these sensors on UUV are analyzed. Experimental results showed these pressure sensors have different performances. Based on the analysis of the results, MPX AP sensor is more suitable to be applied to UUV with low cost budget. For the depth from 0 to 30 meter, MPX 4250 AP is selected while MPX 5700 AP is for the range of depth up to 70 meter.
javad Mashayekhifard; M.A. Nekoui; A. Khaki Sedigh
Volume 6, Issue 2 , June 2012
Abstract
Minimal stopping distance, guaranteed steering ability and stability are the three most important purposes in Anti-lock Braking System (ABS) realm. The ABS system is a nonlinear, time variant and multivariable system with some uncertainties. Some research work has been carried out on ABS control systems ...
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Minimal stopping distance, guaranteed steering ability and stability are the three most important purposes in Anti-lock Braking System (ABS) realm. The ABS system is a nonlinear, time variant and multivariable system with some uncertainties. Some research work has been carried out on ABS control systems using intricate methods which are expensive to implement. In this paper at the first step the system interference is decreased via decoupling matrix and the ABS is controlled with a robust diagonal controller. In fact, a decentralized control technique is used for our ABS control mechanism. At the second step we exploit a multivariable technique in linear control to attack the problem. This is the Designed Linear Control with Multivariable Technique. The Optimal Eigenstructure Assignment with Genetic Algorithm (GA) method is also applied. Simulation and comparison studies are used to show the effectiveness of the proposed methods.
Mohammad Vatankhah; Seyyed Mehdi Hosseini
Volume 6, Issue 2 , June 2012
Abstract
In this paper optimum size and location of distributed generators (DGs) are determined for maximizing voltage profile and minimizing line losses in distribution systems. For this purpose, Particle Swarm Optimization algorithm (PSO) approach is proposed. The significant innovation of this research paper ...
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In this paper optimum size and location of distributed generators (DGs) are determined for maximizing voltage profile and minimizing line losses in distribution systems. For this purpose, Particle Swarm Optimization algorithm (PSO) approach is proposed. The significant innovation of this research paper is using new coding in (PSO) which includes both active and reactive powers of DGs to achieve better voltage profile improvement and line loss reduction. Furthermore, four set of weighting factors are chosen based on the importance and criticality of the different loads. The effectiveness of the proposed method is examined in the 33 bus distribution systems. The results show that determination of optimum size and location of DGs has a considerable effect on voltage profile improvement and line loss reduction.
Nagarajan Shola; S. Rama Reddy
Volume 6, Issue 2 , June 2012
Abstract
Most of the industrial operations involve the use of induction motor drives. The operations of be fault tolerant. This paper investigates the fault operation of a single phase open the drives are so crucial in some events that any fault in the operation of drive could result in serious loss to the industry ...
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Most of the industrial operations involve the use of induction motor drives. The operations of be fault tolerant. This paper investigates the fault operation of a single phase open the drives are so crucial in some events that any fault in the operation of drive could result in serious loss to the industry in terms of capital and raw materials. Hence, it is necessary that an induction motor drive should circuit fault in the drive by performing fault analysis on the harmonic spectrum of the current waveforms. A fault tolerant system is proposed which can operate even after occurrence of the fault in runtime. The simulation studies are done using MATLAB simulation tool and the results are presented.
