Search results for "cogging torque"
showing 3 items of 13 documents
Optimization of Permanent Magnet Shape for Minimum Cogging Torque Using a Genetic Algorithm
2004
The paper presents an approach to minimization of the cogging torque in permanent magnet (PM) machines using surface-mounted magnets with discrete skew angle. For the purpose of determining the proper arrangement of PM-pole slices, an optimization procedure based on a genetic algorithm is applied. The torque and objective function are determined from a simplified model for torque calculation only partially supported by three-dimensional (3-D) field solution. The results are validated against the 3-D finite-element model as well as experimental data obtained from a prototype machine. A new outer-rotor brushless dc motor motor for an electric fan is considered as a sample model.
Analysis of Torque Developed in Axial Flux, Single-Phase Brushless DC Motor With Salient-Pole Stator
2004
An analysis of the torque developed by a single-phase disc brushless permanent magnet motor with salient-pole stator is presented. The machine represents a new family of brushless disc motors with the starting torque issue appearing to be most challenging. To produce a starting torque, the permanent magnets on one of the rotor discs are distributed nonuniformly. However, this significantly distorts a shape of the cogging torque versus rotational angle characteristic which, in turn, affects a waveform of the overall torque. A three-dimensional (3-D) finite-element model is used for the purpose of determining of angular variations of the torque developed by the motor. To find how the torque v…
The role of the effect of manufacturing tolerances on a tubular linear ferrite motor
2015
Electric machines are often designed without considering workmanship and materials tolerances. Their manufacturing process involves a series of steps, starting with raw materials and ending with the machine assembly. In each of these steps occur deviations due, for instance, to mistakes in positioning tools or to the tolerances in the electrical and magnetic characteristics of the materials. These deviations may cause unwanted parasitic effects such as torque ripple, losses or acoustic noise. Such effects have to be considered especially in machines used in industrial drives for high performance applications. Moreover the tolerances in the magnetic materials have a considerable effect on th…