# space vector modulation for induction motor drive

Topics: Electric motor, Variable-frequency drive, Electrical engineering Pages: 15 (2096 words) Published: May 9, 2014
﻿Research Journal of Applied Sciences, Engineering and Technology Research Article

Digital Simulation of Space Vector Modulation Based Induction Motor Drive K.Vijaya Bhaskar Reddy* , Research Scholar, Andhra University, waltair, A.P, India vijayabhaskarareddy.k@bvrit.ac.in, G.V. Siva Krishna Rao, Professor, Dept. of Electrical Engineering, Andhra University waltair, A.P, India, gvskrishna_rao@yahoo.com T.S.Surendra ,Principal,Dept of Electrical and Electronics Engineering,BVRIT,Narsapur,Medak,AP,India,surendra.ts@gmail.com

Abstract- This paper deals with simulation of Space vector modulated inverter fed induction motor drive. The drive system is modeled using matlab simulink and the results are presented. This drive has advantages like reduced harmonics and heating. Fixed AC is converted into DC and this DC is converted into variable voltage and variable frequency AC using SVM inverter. The output of SVM is applied to the stator of induction motor. The simulation results are compared with the analytical results. The FFT analysis shows that the current spectrum has reduced harmonics compared to the conventional system. Keywords: Induction motor, MATLAB, SVM, VSI

Introduction
Like most motors, an AC induction motor has a fixed outer portion, called the stator and a rotor that spins inside with a carefully engineered air gap between the two. Virtually all electrical motors use magnetic field rotation to spin their rotors. A three-phase AC induction motor is the only type where the rotating magnetic field is created naturally in the stator because of the nature of the supply. DC motors depend either on mechanical or electronic commutation to create rotating magnetic fields. There is no direct approach to have the controlled outputs from the commanded inputs. So it is necessary to generate equivalents of the inputs for the output control. This is achieved by three-phase to two-phase transformation where the output equivalent currents for flux and torque respectively are obtained. The per phase equivalent circuit of the machine, is valid only in steady state condition. In adjustable speed drives, the machine normally constituted as element within a feedback loop, and therefore its transient behavior has to be taken into consideration. Besides, high performance over control, such as space vector control is based on the dynamic d-q model of the machine. Therefore, we go for d-q model to understand space vector control principle. The machine model can be described by differential equations with time-requires mutual inductance, but such a model tends to be very complex. “ A space vector modulation Algorithm for Torque control of Inverter fed Induction Motor Drive” is given by Ciro Attaianese Et al [1] The Advent of vectorial control strategies in conjunction with space vector modulation techniques for voltage source inverters have made possible to achieve high quality current and torque responses in induction motor drives. “A Sensorless Vector Control Scheme for Induction Motors using a Space Phasor based Current Hysteresis Controller” s given by Ebenezer V. Et al [2]. This scheme measures the stator current hysteresis error direction to determine the rotor flux position, during inverter zero vector states. This measurement of the rotor flux position is done indirectly by sensing the motor back emf. “Space Vector representation of advanced motor models for vector controlled induction motors” is given by S. Williamson Et al [3]. This method presents a transient induction motor model that accounts for skin effect and saturation in both the main and rotor leakage flux paths is described. and also shown that magnetizing flux oriented control is a more suitable form of vector control. “A Stator-flux-oriented Vector-Controlled Induction Motor Drive With Space-Vector PWM and Flux-Vector Synthesis by Neural Networks” is given by Joao O.P. Pinto Et al [4] This method used the ANN’s, when implemented by...

References: [3] S.Chakrabarti, M. Ramamoorthy and V.R.Kanetkar, 1997, “Reduction of Torque Ripple in Direct Torque Control of Induction Motor Drives Using Space Vector Modulation Based Pulse Width Modulation” Proceedings of IEEE Transactions,7803-3773-5/97.
[4] Ebenezer V., K.Gopakumar and V.T.Ranganathan, 1998, “A Sensorless Vector Control Scheme for Induction Motors using a Space Phasor based Current Hysteresis Controller”, proceedings of IEEE Transactions, 26-31.