Axial-field Permanent Magnet Brushless Research Articles

A novel Integral-force technique for the analysis of an axial-field permanent-magnet brushless DC motor using FE method

In this paper, a novel integral-force technique to calculate the developed torque of an axial-field permanent-magnet brushless dc (PM BLDC) motor using minimum requirement of two-dimensional (2-D) finite-element (FE) analyses is presented. Using this method, the designer can find out the actual performance of the axial-field PM BLDC motor using 2-D FE analysis rather than a three-dimensional (3-D) FE analysis. The design data of a 70 W, three-phase, 24 V, 6 pole, 350 rpm axial-field PM BLDC motor designed using a developed computer-aided design program have been used to work on the developed torque using the proposed new method as well as using 3-D FE analysis. The peak torque calculated in 3-D FE analysis is 2.2608 Nm as against the 2.2705 Nm obtained from the integral-force technique.

Computer aided design of an axial-field permanent magnet brushless dc motor for an electric vehicle

This article presents the computer-aided design and analysis of a pancake-type three-phase axial-field permanent magnet brushless dc motor meant for the direct drive of an electric two-wheeler. The motor has been designed for accommodating inside the rim of the wheel. Initially, the motor design was carried out using the conventional procedure. Then three-dimensional finite element analysis was carried out to arrive at the optimum design by tuning the geometry to achieve the best utilization of all materials used. The effects of all machine parameters on performance of the motor have been studied in detail and the results of this parametric study are provided. The entire design procedure is explained with the help of a flow chart. All steps involved in the design of the motor such as selection of the configuration, design of the magnetic circuit, selection of materials, calculation of machine parameters, and calculation of performance are discussed.

Effects of slot closure by soft magnetic powder wedge material in axial-field permanent magnet brushless machines

The article reports on a study of the effects of slot closure in axial-field permanent magnet brushless machines by a two-dimensional finite element method (2D FEM) of analysis. The closure of the slots is made by using soft magnetic powder wedge material. Parameter values and machine performance for the open and closed slot configuration are computed. In order to test the 2D FEM model, calculated results are compared with measurements and favorable agreement is shown.

Optimum values for magnet and armature winding thickness for axial-field permanent magnet brushless DC motors

When the motor thickness and the required starting torque are set for an axial-field permanent magnet brushless DC motor, the optimal ratio of the permanent magnet thickness to armature winding thickness is 2:1 because the copper loss of the armature windings is kept to a minimum. This conclusion is based on a new method presented by the authors in which factors such as loop resistance, a radial air gap magnetic flux density approximated by curves of second order, and an experimental formula for the leakage coefficient are incorporated. The demagnetization curves of the magnets are assumed to be linear. The new method is also applicable to estimating torque, current, and input power at the start. These items can be more promptly estimated without a computer program, and the physical insight is more easily gained by the aid of the new method than a 3-D finite element method.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>