NdFeB VERSUS FERRITE IPM MOTOR FOR AUTOMOTIVE A.C. COMPRESSOR ELECTRIC DRIVING: MODELING AND FEM-EMBEDDED OPTIMAL DESIGN
Article Sidebar
Published
Jan 7, 2013
Download
Statistic
Main Article Content
Abstract
Automotive a.c. compressor, for an average of
2kW at 6000 rpm, constitutes a major power automotive consumer; its electrification by a high efficiency (above 90%) variable speed drive is claimed to produce at least 33% energy savings. High energy (NdFeB) PMSM with surface and interior PM rotors have been tried for the purpose, for a motor efficiency above 93 - 94% which, for a PWM converter efficiency of 96%, would meet the typical
90% drive efficiency automotive requirements. However, the problem is the high recent price of sintered NdFeB permanent magnets. In view of automotive intensive electrification recent trends, the present paper investigates
the performance of a dual (axial and radial) PM flux concentration Ferrite IPM (Br
=0.45T) rotor versus NdFeB IPM (Br =1.13T) rotor motor for such a demanding application. The main contributions of the paper include: a quasi 3D magnetic circuit nonlinear model of IPMSM with NdFeB (one piece/pole) and of a dual PM flux concentration spoke-Ferrite-IPM rotor 6 slot/8 pole SM; an optimal analytical design methodology with embedded 2D FEM to verify the average torque production automatically, (in axial and radial cross-section) FEM inquiries to obtain, by tapered airgap and 2-shifted-segments-rotor, a reasonable cogging torque and a pretty sinusoidal emf such that to yield less than 5% total full torque pulsations for sinusoidal (vector) current control.
About the same 95% machine efficiency is obtained with both NdFeB and Fe
2kW at 6000 rpm, constitutes a major power automotive consumer; its electrification by a high efficiency (above 90%) variable speed drive is claimed to produce at least 33% energy savings. High energy (NdFeB) PMSM with surface and interior PM rotors have been tried for the purpose, for a motor efficiency above 93 - 94% which, for a PWM converter efficiency of 96%, would meet the typical
90% drive efficiency automotive requirements. However, the problem is the high recent price of sintered NdFeB permanent magnets. In view of automotive intensive electrification recent trends, the present paper investigates
the performance of a dual (axial and radial) PM flux concentration Ferrite IPM (Br
=0.45T) rotor versus NdFeB IPM (Br =1.13T) rotor motor for such a demanding application. The main contributions of the paper include: a quasi 3D magnetic circuit nonlinear model of IPMSM with NdFeB (one piece/pole) and of a dual PM flux concentration spoke-Ferrite-IPM rotor 6 slot/8 pole SM; an optimal analytical design methodology with embedded 2D FEM to verify the average torque production automatically, (in axial and radial cross-section) FEM inquiries to obtain, by tapered airgap and 2-shifted-segments-rotor, a reasonable cogging torque and a pretty sinusoidal emf such that to yield less than 5% total full torque pulsations for sinusoidal (vector) current control.
About the same 95% machine efficiency is obtained with both NdFeB and Fe