JEE_V9_N2_RevP1 P. Ramana K. Alice Mary M. Surya Kalavathi A. Swathi Journal on Electrical Engineering 2230 – 7176 9 2 49 59 Permanent Magnet Synchronous Motor, Parameter Estimation, Model Reference Adaptive System, State Observer Permanent Magnet Synchronous Motor (PMSM) drives are being used increasingly in a wide range of applications, such as machine tools, robotics, aerospace generators, actuators and electric vehicles. It is extensively used in industrial applications due to it's advantageous features such as high efficiency, high torque to inertia ratio, low noise and robustness. In advanced motor control system, an accurate knowledge of motor parameters are essential in order to achieve better performance. Machine parameters are classified into electrical parameters such as resistances of windings and d, q axes inductances of both stator and rotor and mechanical parameters such as angular position, speed, moment of inertia and viscous friction coefficient. Various types of parameter estimation methods for PMSM are available in the literature such as back e.m.f. based method, signal injection based method, state observer based method, Model Reference Adaptive System (MRAS) based method etc. This paper presents a review of all these methods used to estimate the parameters of a Permanent Magnet Synchronous Motor. October - December 2015 Copyright © 2015 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=3719