چكيده به لاتين
Flux Switching Permanent Magnet (FSPM) motors can be useful for electrical submersible pump (ESP) applications due to their benefits. These kinds of motors don’t have the self-starting ability and should be controlled for this purpose and appropriate performance. Most proposed control methods for FSPMs need the rotor position. However, due to the long distance between the drive and the motor, and a harsh environment in oil fields, the signals from rotor position sensors are not reliable. Therefore, a sensorless control method should be taken into account. Subsequently, a sensorless method based on the extended Kalman filter (EKF) is proposed for the FSPM motor control which is supplied by a long cable. Indeed, due to the long distance from drive to the motor in ESPs, the motor must be supplied by a long cable. Therefore, it is essential to consider the cable parameters in the model to apply to the EKF. In the thesis, I have developed the motor model to consider the cable effect for the accurate estimation of the rotor position and velocity. Besides, since there is limits for motor diameter in ESPs, the motor length must be increased to provide the demanded torque. When the proportion of the length to the diameter of the motor increases, a phenomenon occurs in which the shaft of the motor tends to twist. This phenomenon is negligible mechanically or even electrically in conventional motors. However, since the FSPM motors usually have many poles and on the other side, the proportion of the electrical angle to mechanical angle is twice than other conventional PM synchronous motors, the twisting affects the performance of the motor in ESP. Consequently, in the thesis, I proposed a method to estimate the twist angle to be considered in the sensorless motor control.
