چكيده به لاتين
In recent years permanent magnet motors have been used in a variety of application due to high efficiency, high reliability, and high power and torque density. In this motor, torque is produced by the interaction between the electric field and the permanent magnet field. So any interruption in this two parts of machine leads to a decline in torque density of the motor. Demagnetization is one of the disruptive phenomena in the PM motors. This phenomenon caused by armature reaction, high temperature, and self-demagnetization. Therefore in this thesis demagnetization modelling of Ring Winding Axial Flux Permanent Magnet motor conducted and demagnetization tolerant is evaluated.
In this thesis, first an introduction about demagnetization phenomenon, the importance of the subject, affecting factors, and modelling methods are investigated. Then demagnetization modelling of the newly introduced RWAFPM motor is conducted using Time Stepping Finite Element Method (TSFEM). In this method, a modified demagnetization algorithm is used in the way that at each step of the rotor position, demagnetization is considered and in the next rotor position the new residual magnetic flux density is used for the magnet. In the following, the Magnetic Equivalent Circuit (MEC) method is presented for demagnetization modelling of RWAFPM motor due to high time and memory consumption of FEM method which makes it inappropriate at the early design steps. Also, the obtained results of two methods are compared and analyzed.
