DESIGN AND PERFORMANCE OF PERMANENT MAGNET GENERATORS

Abstract

This dissertation presents the design aspects and performance of permanent magnet generators, used in air craft and portable applications. un account of the absence of a separate exciter, permanent magnet generators are free from commutation troubles, and their associated radio interference. Light weight, small size and higher efficiency are additional features of n.m. generators. Design of the p.m. magnet, including the ri thoda of its stabilization and magnetization, has been considered in detail. Equations for estimating pole leakage which forms a considerable amount of the total flux, have also been derived. Inst of the remaining dimensions are calculated In the same way as in apnchronous machine a with wound••field,, and have, the refore , been discussed briefly. In addition, mechanical )roblems encountered during the manufacturing process have been considered. Expressions for the machine parameters have been developed with the help of the equivalent magnetic circuit of the p.m. generator. Tensors have been applied to derive the performance equations. Although a perfect control of the output voltage of the p.m. generator is not possible because of the absence of a separate excitation system, some indirect methods for the voltage control have been suggested,, which are in actual use. LTl Experimental analysis to verify some of the theoretical