Numerical and Experimental Investigation of an Improved Flux Path Brushless-DC Machine for Variable Speed Applications

In this paper, analysis of an improved axially flux path brushless-dc machine (IAFP-BLDM) with the enhanced housing including its operation principle and particular structure is presented. The proposed configuration efficiently improves the magnetic performance by reducing the reluctance and leakage flux. Moreover, unlike the conventional brushless-dc generators, the proposed configuration of this paper utilizes an assisted dc field coil replaced with the permanent-magnet excitation. As the main salient feature of including the dc field coil which increases the controllability of the flux, providing a regulated terminal voltage in a very wide range appropriate for variable speed applications can be addressed. In this paper, by employing the finite-element method, the 3-D magnetic field analysis of the IAFP-BLDM is carried out by using the MagNet CAD package (Infolytica Corporation Ltd.). In order to verify the actual performance of the proposed configuration, a 1.5 kW, 3600 rpm, 9-6 salient poles and two layers are manufactured and tested followed by a discussion on the results. The output results were in good agreement with the analysis results, and also the output performance was verified by the experiment set.