The dynamic analysis of a spoke-type permanent magnet generator with large overhang

The purpose of this paper is characteristic analysis of a permanent magnet generator (PMG) for automatic voltage regulator (AVR) power of a brushless synchronous generator. However, this PMG has a spoke-type permanent magnet rotor with a large overhang for high power density; characteristic analysis considering the concentration effect of the air-gap flux density due to the overhang should be performed. Three-dimensional (3-D) transient finite element method (FEM) analysis is a good solution for the overhang parameter, but this method needs too much calculation time. In this paper, we examined the overhang effects based on overhang length and material of rotor core by using two-dimensional (2-D) and 3-D static FEM analysis, and proposed a 2-D dynamic FEM model considering the overhang parameter, which gives good and rapid results. The proposed method is verified by the test results of no-load, load, and short-circuit test.