Abstarct: The unique characteristics of permanent magnet machines include high power density, low inertia, high torque to inertia ratio, fast acceleration, simplicity of maintenance, power factor and better efficiency than DC and induction motors, which make them more useful. On the other hand, faults have always been an integral part of electric machines. Hence, it is clear that the ability to model, predict and detect faults is very important. Permanent magnet electric machine faults are divided into three categories: mechanical, electrical and magnetic. One of the most common faults in axial flux permanent magnet machines is eccentricity, which can have devastating effects. Unfortunately, most previous studies have focused on this fault and how to detect it in a slotted structure with a conventional winding. Therefore, in this thesis, the effect of eccentricity faults on the performance of four structures, one-sided slotted, one-sided non-slotted, two-sided slotted and two-sided non-slotted. The finite element method (FEM) has been already used for modeling eccentricity fault in disc type PM machine. Applying three-dimensional (3D) FEM to this motor is essential. However, 3D-FEM is a very time-consuming technique. Therefore, it is more appropriate to use an analytical technique to investigate the impact of different parameters upon the motor's performance. The existing analytical methods usually represent a qualitative overview of the faulted machine. In this paper, a precise and quick analytic method is introduced, reflecting the impact of various important parameters, including rotor angle and fault position on the motor's performance. This method enables the calculation of the induced voltage in a search coil. Comparing the results obtained from the proposed method and FEM, in both the no-load and full-load conditions, confirms the method's accuracy. Finally, the impact of the search coil's various parameters of on dynamic and static eccentricity fault is examined. In addition, choosing the proper search coil pitch for eccentricity faults detection is discussed.