iosr-JEEE   Volume-9 ~ Issue-2 ~ March-April 2014

Abstract: In thispaper comparative performance analysis of MOSFET based& IGBT based single phase inverter has been evaluted. The paper compares overall THD of output voltage of thesetwoproposedinverters. Heresinusiodal PWM scheme has been usedwhich compares a sinusoidalreference voltage with a carrier basedmodulating signal to generategating pulse for inverter circuit. Power quality of inverter output voltage has a great importance now a dayswhichdepends on overall THD.This paperdescribes how THD of inverter output voltage canbecontrolled by varyingfrequency of carrier signal frequency.

Keywords: SPWM, IGBT, MOSFET, THD, MATLAB SIMULINK.

[1]. P.S. Bhimra, Power Electronics, (Khanna Publishers , 2013)
[2]. Pankaj H Zope, Pravin G. Bhangale, PrashantSonare, S.R. Suralkar, Design and Implementation of Carrier Based Sinusoidal PWM Inverter, International Journal of Advanced Research in Electrical, Electronics and Instrumentation Engineering, 1(4),2012.
[3]. C.S. Sharma, TaliNagwani, Simulation and Analysis of PWM Inverter Fed Induction Motor Drive, International Journal of Science, Engineering and Technology research (IJSETR), 2(2), 2013, 359 – 366.
[4]. Amit Kumar Sharma, Tushar Deep Saxena, Sirazul Islam, Arun Kumar Yadav, Performance Analysis of Three Phase PWM Voltage Source Inverter Fed Three Phase Induction Motor Drive, International Journal of Advanced Electrical and Electronics Engineering (IJAEEE), 2(2), 2013, 45 – 52.
[5]. Arindam Dutta, ThirtharajSen, S. Sengupta, Reduction in Total Harmonic Distortion in a Non – Linear Load with Harmonic Injection Method, International Journal of Recent Trends in Engineering, 1(4), 2009, 85 - 89.

Abstract: Nowadays the number of mobile subscribers is increasing all over the world, so the system for the communication has to be improved. Mixed Excited Linear Prediction (MELP) algorithm is developed for reducing the bandwidth of the signal as well as transmission of large data on a single channel. This results in increase channel capacity. This also results in, increasing the number of user in a channel. MELP is basically a speech coding method, relying on a Speech Encoder and Speech Decoder. The MELP speech coder reduces the redundancy of the signal and compresses it which is represented by the MELP code.

[1] Wai C. Chu, "Speech coding Algorithems: Foundation and Evolution of Standardized Coders " A John Wiley & Sons, Inc.
[2] John G Proakis & Dimitris G Manolakis : "Digital Signal Processing : Principles, Algorithms, and Applications" (Prentice Hall India, 3rd edition).
[3] Sanjit K Mitra : "Digital Signal Processing : A computer Based Approach" (TMH, 2nd edition.)
[4] Theodore S. Rappaport: "Wireless Communications Principles and Practice"( PEARSON Education, 3rd edition ).
[5] Antoniou, A. "Digital Filters: Analysis, Design, and Applications"( McGraw-Hill, New York.).
[6] Burrus, C. S. and T. W. Parks (1985). "DFT/FFT and Convolution Algorithms", John Wiley &Sons, Hoboken, NJ. (1993).
[7] Gersho, A. and R. M. Gray. Vector Quantization and Signal Compression, 4th printing, Kluwer Academic Publishers, Norwell, MA. (1995).

Abstract: In this paper is to explain the unbalance electric scenario in the Power System. To explain how unbalance condition is one of the most important problems associated with power quality and creates several disturbances to the Power System. It includes the Harmonic reduction techniques to improve the power quality and it also includes the simulation for the same. This project presents a multilevel inverter topology suitable for the generation of 3 phase supply. A simple and fast carrier based Direct-torque control with pulse width modulation (PWM) scheme is also proposed for the topology which utilizes only the sampled amplitudes of the reference wave for the PWM timing computation. Individual independent inverter is combined to form the three phase output. Because of the loads are specific and it can be varied.

Index term: multilevel-inverter, PWM techniques, MSP 430 controller, Induction motor, V&I balanced condition.

[1] "Multi-level conversion and voltage-source inverters high voltage choppers" t.a. meynard, h. foch 1992.
[2] "Improved Method of Voltage Utility Factor for PWM Control Method of Five-Leg Inverter" Kazuo Oka*' and Yusuke Nozaw
[3] "Weighted Control of Traction Drives With Parallel-Connected AC Machines" Alain Bouscayrol, Phillipe Delarue,Paul-Etienne Vidal, Xavier Kestelyn 2011.
[4] "A Novel Control Scheme of a Parallel Current-Controlled PWM Inverter" Satoshi Ogasawara Jin Takagaki, Hirofumi Magi september/October1992.
[5] "Optimized modulation techniques for the generalized N-level converter"M. Fracchia, T. Ghiara, M. Marchesoni 1992.
[6] "Characteristics of Independent Two Induction Motor Drives Fed by a Four-Leg Inverter" Kouki Matsuse, and Kazuo Oka 2011.
[7] "A Stator-Flux-Based Vector Control Method for Parallel-Connected Multiple Induction Motors Fed by a Single Inverter" yasushi Matsumoto, Chiharu Osawa, Tetsuya Mizukami 1998.
[8] "Characteristics of Speed Sensor less Vector Controlled Dual Induction Motor Drive Connected in Parallel Fed by a Single Inverter" Hirotoshi Kawai, Yuusuke Kouno, and Jun Oikawa 2004.