<p><p>A permanent magnet synchronous motor is traditionally controlled from measured</p><p>values of the angular velocity and position of the rotor. However, there is a wish</p><p>from SAAB Avitronics to investigate the possibility of estimating this angular</p><p>velocity and position from the current measurements. The rotating rotor will</p><p>affect the currents in the motor’s stator depending on the rotor’s angular velocity,</p><p>and the observer estimates the angular velocity and angular position from this</p><p>effect.</p><p>There are several methods proposed in the article database IEEE Xplore to</p><p>observe this angular velocity and angular position. The methods of observation</p><p>chosen for study in this thesis are the extended Kalman filter and a phase locked</p><p>loop algorithm based on the back electro motive force augmented by an injection</p><p>method at low velocities.</p><p>The extended Kalman filter was also programmed to be run on a digital signal</p><p>processor in SAAB Avitronics’ developing hardware. The extended Kalman filter</p><p>performs well in simulations and shows promise in hardware implementation. The</p><p>algorithm for hardware implementation suffers from poor resolution in calculations</p><p>involving the covariance matrices of the Kalman filter due to the use of 16-bit</p><p>integers, yielding an observer that only functions in certain conditions.</p><p>As simulations with 32-bit integer algorithm performs well it is likely that a 32-</p><p>bit implementation of the extended Kalman filter would perform well on a motor,</p><p>making sensorless control possible in a wide range of operations.</p></p>
| Identifer | oai:union.ndltd.org:UPSALLA/oai:DiVA.org:liu-17313 |
| Date | January 2009 |
| Creators | Petersson, Fredrik |
| Publisher | Linköping University, Department of Electrical Engineering |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, text |
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