Three-dimensional finite element design procedure for the brushless doubly fed machine

Graduation date: 1995Brushless Doubly Fed Machines (BDFM) have potential advantages in variable\ud speed generation and adjustable speed drive applications. The most significant of these\ud advantages is a reduction in the power electronic converter rating, and therefore a\ud reduction in overall system cost. Presently, efforts are being directed at optimizing the\ud design of the BDFM and investigating areas of commercial feasibility. One possible aid\ud in the investigation of design alternatives is finite element analysis.\ud Finite element analysis is a numerical method for determining the field\ud distribution in a dimensional model. Finite element techniques have been successfully\ud used for some time in the design of induction, reluctance and permanent magnet\ud machines. However, the characteristics of the BDFM require adjustment of the finite\ud element design procedure used for conventional singly-fed induction machines. In this\ud thesis, a three-dimensional finite element design procedure for modeling the BDFM has\ud been developed. This design procedure avoids the difficulties previously associated with finite element modeling of the BDFM.\ud The three-dimensional finite element design procedure developed in this thesis was used to model the 6/2 pole 5 horsepower BDFM laboratory machine. From the simulation results, the induced currents in the BDFM rotor bars were calculated.\ud In the course of investigating three-dimensional finite element analysis for the BDFM, two different commercially available finite element analysis software packages were examined and tested. The first was Maxwell 3D Field Simulator produced by Ansoft Corporation, and the second was MSC/EMAS (Electromagnetic Analysis System) and MSC/XL by MacNeal-Schwendler Corporation. These two software packages are compared and their advantages and disadvantages/limitations are discussed.\ud A tutorial for setting up and solving a three-dimensional BDFM model using MSC/XL and MSC/EMAS is presented. This goal of this tutorial is to guide a new user of MSC/XL and MSC/EMAS through the creation, setup, simulation, and analysis of a BDFM model. This tutorial contains condensed information included in the MSC/XL and MSC/EMAS program documentation provided by MacNeal-Schwendler. In addition, modeling techniques particular to the BDFM, which are not included in the program documentation, are described. This tutorial is applicable only to those individuals interested in learning how to use MSC/XL and MSC/EMAS in order to simulate a BDFM model