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Sensor-Less Control of Permanent Magnet Synchronous Motor Using High Frequency Signal Injection
, M.Sc. Thesis Sharif University of Technology ; Tahami, Farzad (Supervisor)
Abstract
In this thesis one of the sensorless methods which exploits the existing anisotropies of the rotor is utilized to estimate rotor position. In order to implement this method, first a high frequency voltage is injected in a specific, time-varying direction and then the corresponding current response would be observed in order to estimate the rotor saliency position. The estimation of rotor position would be more precise as the magnetic anisotropy due to rotor saliency increases and as a result the effect of noise and different disturbances in estimation of rotor position would be decresed. The effect of stator resistence is one of these disturbances which is usually neglected as a result of...
Sensorless control of non-salient PMSM using asymmetric alternating carrier injection
, Article 2011 IEEE Symposium on Industrial Electronics and Applications, ISIEA 2011, 25 September 2011 through 28 September 2011 ; September , 2011 , Pages 7-12 ; 9781457714184 (ISBN) ; Tahami, F ; Sharif University of Technology
Abstract
Sensorless control of permanent magnet synchronous motors allows reducing cost and complexity, and increasing mechanical robustness and noise immunity. Sensorless methods based on high frequency carrier injection have attracted considerable attention in recent years as they can estimate rotor position in a wide speed range. These methods employ anisotropic properties of rotor to estimate rotor position in ac machines. With internal permanent magnet motors, the high frequency signal injection method can deliver precise sensorless control, however in surface-mounted permanent magnet machines, where a small saliency arises from main flux saturation, the estimation of rotor magnet position is...
Effect of reduced frequency on the aerodynamic behavior of an airfoil oscillating in a plunging motion
, Article Scientia Iranica ; Volume 16, Issue 1 , 2009 , Pages 40-52 ; 10263098 (ISSN) ; Rasi Marzabadi, F ; Sharif University of Technology
2009
Abstract
A series of low speed wind tunnel tests were conducted to study the unsteady aerodynamic behavior of an airfoil sinusoidally oscillating in plunge. The experiments included measuring the surface pressure distribution over a range of reduced frequencies, k = 0.03 - 0.06. In addition, steady state data were acquired and were used to furnish a baseline for further analysis and comparison. The model was oscillated with amplitude of ±15 cm and at three different mean angles of attack of 0, 10° and 18°. The unsteady aerodynamic loads were calculated from the surface pressure measurements, 64 ports, along the chord for both upper and lower surfaces. The plunging displacements were transformed into...