Design of a brushless A.C. servo-motor using neodymium iron boron permanent magnet meterial

摘要

The excellent performance characteristics of Brushless Servo-motors have led to their widespread use in areas such as Robotics, CNC Machines and in the Aero-space Industry. The development of Neodymium Iron Boron permanent magnet material with the highest available Energy Product levels promised improved motor performance coupled with reduced magnet costs. However this material exhibits large changes in magnetic properties with temperature when compared with Samarium Cobalt magnets, the permanent magnet material commonly used in these applications. This research examines the feasibility of substituting Samarium Cobalt magnets with Neodymium magnets in a redesigned Servo-motor.ududEquations are developed which predict the motor performance based on design input data, machine physical dimensions and magnetic properties of the permanent magnet material. A winding analysis program is developed and is used to investigate the consequences of different winding configurations. The validity of this analysis is examined experimentally. Motor heating tests are performed to determine the maximum in-service magnet temperatures and these results are presented. Design studies are conducted and a prototype motor using Neodymium magnets was built and tested. The design predictions and the test results are used to determine the suitability of Neodymium Iron Boron material for high performance Servo-motor applications.