Evaluation of Permanent Magnet Generator Manufactured Using Postassembly Magnetization

This paper investigates the effect of a postassembly magnetization (PAM) process on the performance of a permanent-magnet (PM) generator with anisotropic rare-earth magnets. This process utilizes the stator windings of the generator to magnetize the magnets after complete assembly. For manufacture using this method, two orthogonal directions of a magnet may be subjected to magnetizing flux including the nonpreferred direction and this may result in weaker magnetization for anisotropic magnets. The performance can thus be affected and needs to be evaluated. The magnet characteristics are initially studied using a commercial magnetizing fixture for understanding of the magnet behavior under incomplete magnetization and magnetization in nonpreferred directions. A prototype PM generator manufactured using PAM is first simulated using finite element analysis and then tested to validate the performance.