| To date, the performance of speed-sensorless variable speed induction motor drives have been limited their use to specific applications where the motor is operating in specific ranges (either speed or power, load etc). Specific performance requirements have not yet been adequately addressed by such systems including wide operating speed range, control of small fractional horsepower motors and development of a control strategy that can easily be implemented on commercially available micro-controllers with minimal hardware.; A relatively new method of rotor speed estimation uses the harmonics generated in the stator current by the winding slots or bars in the rotor. This method has the advantage that it can determine the speed of the motor independently of motor type or its electrical parameters. This method will be the focus of the thesis research.; In particular the application of a Fast Orthogonal Search (FOS) algorithm to this application is studied. This algorithm allows extraction of motor speed information from the sampled motor current accurately and in a timely fashion, while using a minimal number of samples. (Abstract shortened by UMI.)... |
