Vol 2 Issue 3 July 2014-September 2014

Abstract: Power system stability is the ability of an electric power system, for a given initial operating condition, to regain a state of operating equilibrium after being subjected to a physical disturbance, with most system variables bounded so that practically the entire system remains intact. As the size of interconnected power system is increasing, it is becoming more difficult to maintain synchronization between various parts of the power system. This paper focuses on transient stability analysis on the basis of swing equation by using three different numerical integration methods.

Keywords: Numerical Methods, Transient Stability, Swing Equation, Synchronous Machine, Damping Torque, Euler’s Method, Runga – Kutta’s Method, Point by Point Method.

Title: Transient Stability Analysis of Single Machine Infinite Bus System by Numerical Methods

Author: Chandra Shekhar Sharma

International Journal of Electrical and Electronics Research

ISSN 2348-6988 (online)

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Abstract: This paper presents the design, analysis and implementation of a proposed combined three phase induction motor and its drive system to meet the demand of low-voltage electrical system for hybrid and electric cars, avoiding the high voltage human risks, expensive and complex requirements of the higher voltage insulation and power electronic devices.  Development of Electric Vehicles (EVs) and Hybrid Electric Vehicles (HEVs) will offer many new opportunities and challenges to the power electronics industry, especially in the development of the main traction motor drive. Cascade H-bridge (CHB) multilevel inverter with minimum output harmonics for electric/hybrid electric vehicle applications is proposed in this paper. Switching angles of switch devices are determined by selective harmonic elimination technique. So, the effect of low order harmonics are reduced, as a result the efficiency of system has improved. Moreover, the number of DC voltage sources that used in the proposed inverter is less than conventional multilevel inverters that leads to reduce the inverter costs A conventional 220V 3-ph induction motor has been rewound in order to get the required 48V 3-ph motor. The simulation results are obtained using MATLAB/SIMULINK software.

Keywords:  Electrical Vehicle Reduced Voltage, Induction Motor, Drive Using MLI.

Title: Electrical Vehicle with Reduced Voltage Induction Motor Drive Using MLI

Author: Y.santha kumari, POMYA

International Journal of Electrical and Electronics Research

ISSN 2348-6988 (online)

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Abstract: Errors occur in information during transmission, due to noise on the communication channel. In this paper, we study the unequal error protection capabilities of convolutional codes belonging to the family of rate-compatible punctured convolutional codes. Puncturing is the process of deleting some parity bits from the code-word according to a puncturing matrix. Puncturing increases code rate without increasing complexity. The bandwidth efficiency decreases with increase in redundant bits in coding. By removing these redundant bits through puncturing improves the bandwidth efficiency. Puncturing is the trade-off between rate and performance. In this paper, simulation model of OFDM based WIMAX system has been developed using punctured convolutional codes. The bit error rate performance has been carried out for different code rates like 1/2, 2/3, 3/4, 5/6, 7/8, 11/12 for modulation techniques BPSK and QPSK.

Keywords: BPSK; Convolutional codes; MATLAB; OFDM-WiMAX; QPSK; Puncturing.

Title: Performance Evaluation of Punctured Convolutional Codes for OFDM-WiMAX System

Author: Jasmeen Kaur Bisla, Naveen Dhillon, Kuldeep Sharma

International Journal of Electrical and Electronics Research

ISSN 2348-6988 (online)

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Abstract: In this paper the conventional Marx circuit is analysed mathematically as well as by simulation method. Effect of parameters R₁, R₂ and ratio C1/C2 on front time and tail time have been analysed by Simulink. It was found that there is a particular range of ratio C1/C2 for the parameters of impulse generator under consideration.

Keywords: Analysis of Impulse, Voltage Generator, Effect of Variation.

Title: Analysis of Impulse Voltage Generator and Effect of Variation In Parameters by Simulation

Author: Anitya Kumar Shukla, Dr. Ranjana Singh

International Journal of Electrical and Electronics Research

ISSN 2348-6988 (online)

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Abstract: During their lifetime, multihop wireless mesh net-works (WMNs) experience frequent link failures caused by channel interference, dynamic obstacles, and/or applications’ bandwidth demands. These failures cause severe performance degradation in WMNs or require expensive manual network management for their real-time recovery. This paper presents an autonomous network reconfiguration system (ARS) that enables a multiradio WMN to autonomously recover from local link failures to preserve network performance. By using channel and radio diversities in WMNs, ARS generates necessary changes in local radio and channel assignments in order to recover from failures. Next, based on the thus-generated configuration changes, the system cooperatively reconfigures network settings among local mesh routers. ARS has been implemented and evaluated extensively on our IEEE 802.11-based WMN test-bed as well as through ns2-based simulation. Our evaluation results show that ARS outperforms existing failure-recovery schemes in improving channel-efficiency by more than 90% and in the ability of meeting the applications’ bandwidth demands by an average of 200%.

Keywords: IEEE 802.11, multiradio wireless mesh networks (mr-WMNs), self-reconfigurable networks, wireless link failures.

Title: Wireless Mesh Networks

Author: M.Shanmugapriya, R.Rohini

International Journal of Electrical and Electronics Research

ISSN 2348-6988 (online)

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Abstract: This paper proposes the estimation of mean electrical phase center (MEPC) in different GNSS patch antennas.  In the past, edge diffraction theory is quite complex and difficult to find the exact location of antenna phase center. In this work, an improved and determine the mean electrical phase center of horn and patch antenna in Cartesian coordinates. The Patch antenna can provide higher accuracy in GNSS positioning compare to horn antenna. The experimental results show that the patch and horn antenna phase center variation with change in observation angle and frequency are presented.

Keywords: Anechoic chamber, antenna, global navigation satellite system (GNSS), patch, phase center.

Title: An Improved and Gnss Patch Antenna Techniques for Analysis and Estimation of Phase Centre

Author: G vijaya raju, I.Hemalatha

International Journal of Electrical and Electronics Research  

ISSN 2348-6988 (online)

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Abstract: This paper deals with the implementation of a converter, which allows transfer of power flow between the two dc sources in either direction. This converter can reverse the direction of flow of current, and thereby power, while maintaining the voltage polarity unchanged. The converter is the combination of two successful topologies, namely half bridge topology and current fed push pull topology. Both topologies are connected with high frequency isolation transformer. The primary side has the dc mains and the load, and the secondary side contains the battery to be charged and discharged. When dc main is present the converter operates in buck mode to charge the battery.  On the failure of the dc main the converter operates in boost mode, where the battery regulates the bus voltage and provides power to the load. This bidirectional power flow is achieved by using same power components hence minimizing the hardware.

Keywords: Bidirectional dc-dc converter, boost mode, charging and discharging, current-fed push-pull topology.

Title: A Dual Mode Converter Topology for Low Power Applications

Author: K.V.BINDU, B.NAGARANI

International Journal of Electrical and Electronics Research

ISSN 2348-6988 (online)

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Abstract: High data rates and secured data communication has become an unavoidable need of every mobile users. 3G technology provided greater data speed and secured networks compared to its predecessor 2G or 2.5G. The highest bit rates in commercially deployed wireless systems are achieved by means of Orthogonal Frequency Division Multiplexing (OFDM). The next advance in cellular systems, under investigation by Third Generation Partnership Project (3GPP), also anticipates the adoption of OFDMA to achieve high data rates. But a modified form of OFDMA i.e. SCFDMA (Single Carrier FDMA) having similar throughput performance and essentially the same complexity has been implemented as it has an edge over OFDMA having lower PAPR (peak to average power ratio). SCFDMA is currently a strong candidate for the uplink multiple access in the Long Term Evolution of cellular systems under consideration by the 3GPP. In our project we have worked on PAPR analysis of OFDMA, SCFDMA and various other SCFDMA (with different subcarrier mapping). Though SCFDMA had larger ISI it has lower PAPR which help in avoiding the need of an inefficient linear power amplifier. We analyzed various modulation techniques and implemented various kinds of pulse shaping filters and compared the PAPR for IFDMA, DFDMA and LFDMA (kinds of SCFDMA). The PAPR Performance of IFDMA was found to be better than LFDMA and DFDMA. Like other communication systems, in SCFDMA we encounter many trade-offs between design parameters (such as roll-off factor) and performance.

The project report also constitutes the channel estimation techniques implemented in OFDM systems. Due to multipath fading the channel impulse response fluctuates for different subcarriers in different time slots. So we need to estimate the channel impulse response at various times to extract error free data. As we have taken a slow Rayleigh fading channel in our study we used block type pilot arrangement channel estimation which use LS (least square), MMSE (minimum mean square error) estimator. Due to higher complexity of the MMSE estimator, modified MMSE is implemented where we had to do the tradeoff with the performance. There are various other adaptive estimation techniques like LMS and RLS for estimating blind channels and comb type pilot arrangement estimation techniques for fast fading channels.

Keywords: OFDMA, SCFDMA, PAPR, cyclic prefix, LS, MMSE, MSE, SER, SNR.

Title: PAPR ANALYSIS AND CHANNEL ESTIMATION TECHNIQUES FOR 3GPP LTE SYSTEM

Author: Abhijeet Sahu, Soumyajyoti Behera

International Journal of Electrical and Electronics Research

ISSN 2348-6988 (online)

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Abstract: In this paper, design of a fixed parameter robust STATCOM controller using Loop-shaping procedure is presented. A simple loop shaping method which yields a fixed parameter robust controller has been found suitable to provide good damping characteristics. The graphical loop shaping procedure used in designing a robust STATCOM controller can be significantly improved by embedding some optimization procedure in it. The objective function of the design problem is formulated to include closed loop responses. In this Thesis, a latest evolutionary computational technique called Differential Evolution (DE) has been employed to find the fixed parameter robust controller parameters. DE algorithm and Matlab is used to determine the controller parameter and system stability. 

Keywords:  STATCOM, Differential evolution, MATLAB, Loop Shaping Technique.

Title: DESIGN OF ROBUST STATCOM CONTROLLER USING LOOP SHAPING TECHNIQUE WITH DIFFERENTIAL EVOLUTION

Author: Jyoti Devi, Amandeep Kaur

International Journal of Electrical and Engineering Research 

ISSN 2348-6988 (online)

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Abstract: In this paper, design of a fixed parameter robust STATCOM controller using Loop-shaping procedure is presented. A simple loop shaping method which yields a fixed parameter robust controller has been found suitable to provide good damping characteristics. The graphical loop shaping procedure used in designing a robust STATCOM controller can be significantly improved by embedding some optimization procedure in it. The objective function of the design problem is formulated to include closed loop responses. In this Thesis, a latest evolutionary computational technique called Differential Evolution (DE) has been employed to find the fixed parameter robust controller parameters. DE algorithm and Matlab is used to determine the controller parameter and system stability. 

Keywords:  STATCOM, Differential evolution, MATLAB, Loop Shaping Technique.

Title: DESIGN OF ROBUST STATCOM CONTROLLER USING LOOP SHAPING TECHNIQUE WITH DIFFERENTIAL EVOLUTION: A REVIEW

Author: Jyoti Devi, Amandeep Kaur

International Journal of Engineering Research: A Review

ISSN 2348-6988 (Online)

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Abstract: this “intelligent guidance system for visually impaired” is a guidance system for the blind people based on joystick, ultrasonic sensor ,ir sensor and image processing. Multiple functions are provided like image processing navigation and obstacle avoidance. Smart phone is used for the vision purpose. Zebra crossing and traffic light detection by this camera. Artificial intelligence is also implemented for the indoor navigation and gps module for the outdoor navigation. The major concern for the blind is the traffic junction they are confused weather to cross the junction or ask someone help. Here the camera vision helps to detect zebra crossing and traffic light.gps values lat and long is recorded in a database and kept for future references.

Keywords: Intelligent Guidance System, Visually Impaired, Camera Vision.

Title: INTELLIGENT GUIDANCE SYSTEM FOR VISUALLY IMPAIRED

Author: Freddy Kuruvila, Laxmi Gulappagol

International Journal of Electrical and Electronics Research

ISSN 2348-6988 (online)

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Abstract: Skeletonization proves to be a useful method for description of shape, pattern recognition, retrieving centerline of images, animation. Previously, skeletons were used to find shape of object components, now their use have been extended to many fields such as medicine, military, bio-imagery etc. In this paper we have proposed two thinning algorithms i.e. fast parallel thinning and watershed algorithm  to find skeleton of depth image captured by TOF camera, which can be used in applications like games, medical field as a model. The fruitfulness of algorithm is proved by experimental results.

Keywords:  Skeletonization, ToF camera, Thinning algorithm, dilation.

Title: SKELETONIZATION OF DEPTH IMAGES

Author: Gauri Patil

International Journal of Electrical and Electronics Research  

ISSN 2348-6988 (online)

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Abstract: High-speed fibre optical communication links have become more popular for personal mobile applications. This is a consequence of the increasing demand from the personal information service boom. Compared to the radio frequency domain, optical fibre communication offers much higher speeds and bit rates per unit power consumption. Focus on the modulation aspects of the optical communication, this thesis try to improve the channel immunity by utilizing optimized modulation to the channel. Modulation schemes such as Quadrature Ampitude Modulation (QAM4), QAM16, QAM64, QAM256 have been validated. The combined power and bandwidth requirements suggest that the adaptive modulation schemes can provide reliability when deployed in a real time channel, resulting in improved system performance.

Keywords: Opticle Fibre, QAM.

Title: ACM IN OPTICAL FIBRE

Author: Rekha Sharma, Ankita Mittal

International Journal of Electrical and Electronics Research  

ISSN 2348-6988 (online)

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Abstract: This thesis investigates the performance improvement of OCDMA. To improve the bit error rate of the system uniform fibre bragg grating is used at transmitter and receiver end with same reflectivity. With distance, performance of OCDMA decreases. To check the effectiveness of FBG on OCDMA in optisystem simulink software, various lengths of optical fibre are taken and bit error rate is checked. Comparison of BER and various parameters of eye diagram is done with FBG and without FBG. The overall work is done in optisystem tool specially designed for optical communication.

Keywords: OCDMA, FBG

Title: PERFORMANCE IMPROVEMENT OF OCDMA BY FBG

Author: Ranjan, Ankita Mittal

International Journal of Electrical and Electronics Research  

ISSN 2348-6988 (online)

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Abstract: This Paper presents the Phase Disposition Scheme, which is topology independent. This scheme is used in Multilevel Inverters, interleaved parallel combination. Analysis on the other scheme which is Phase Opposition Disposition has also been performed. The best strategies related to the paralleling of inverters are evaluated, particularly those associated to current balancing between commutation cells of the same phase.

Pulse width modulation (PWM) strategies and methods for multilevel converters are usually developed for series converters. In this paper it is shown that they may be applied to parallel converters using interleaving techniques, given that these converters also have multilevel characteristics. PWM methods based on carriers’ disposition and on zero sequence injection are studied for parallel multilevel inverters. Analysis shows that the best method in terms of load current ripple is the phase disposition method.  The current balancing between commutation cells of the same phase is comparatively superior with this method.  Another objective on which work was done was to analyze these problems and to propose a solution to cancel current imbalance when using POD (Phase Opposition Disposition). The load was chosen to be a three phase induction motor drive and its parameters such as Stator Current, Speed and Electromagnetic Torque have been analysed as such.

Keywords: Multilevel Inverter, POD Modulation Scheme.

Title: THREE PHASE PARALLEL MULTILEVEL INVERTER FED INDUCTION MOTOR USING POD MODULATION SCHEME

Author: N V Bharadwaj, Dr. P Chandrasekhar, B V Hemanth Kumar

International Journal of Electrical and Electronics Research  

ISSN 2348-6988 (online)

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