Fatigue Properties of an Electrical Steel and Design of EV/HEV IPM Motor Rotors for Durability and Efficiency Corus Automotive Engineering

Format:

Conference/Event

Author/Creator:

Gao, Gao, author.

Contributor:

Lindenmo, Magnus

Long, Ray

Pang, Yong

Conference Name:

SAE 2010 World Congress & Exhibition (2010-04-13 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2010

Summary:

With electric vehicles (EVs) and hybrid electric vehicles (HEVs)set to grow in the coming years, design optimizations of electricmotors for automotive applications are receiving more attention.Under demanding duty cycles, the moving part within a motor, therotor, may experience high and varying stresses, which may lead tofatigue failure. Therefore, engineers are facing challenges indesigning efficient and durable motors, especially for interiorpermanent-magnet (IPM) motors, in which the rotors have embeddedmagnets with small "bridges" of laminated electricalsteel to keep the magnets in place.Cost-effective stators and rotors are made from electricalsteels, with high magnetic permeability and low power losses.However, national and international standards for electrical steelsdo not specify mechanical properties. Steel producers wouldnormally state typical mechanical properties only, and no fatigueproperties are available in published literature.This paper describes typical fatigue performance of anelectrical steel grade SURA® M270-35A for EV/HEV motorapplications. Focus will then turn to finite element (FE)structural and magnetic evaluations of various IPM rotor designs.Particular attention will be paid to understanding the influence ofthe magnet pole arrangements, the magnet slot geometry and"bridge" dimensions on rotor fatigue lives androtor-stator air-gap flux densities.By generating and applying fatigue data for electrical steels,in conjunction with FE-based magnetic, structural, and fatiguemodeling, the paper summarizes how various magnet-slot schemes androtor profiles can be assessed under a typical HEV motor dutycycle. Such understanding provides good pointers to optimized motorrotor profiles with balanced durability and magnetic flux densityin the air-gap. The paper demonstrates that, using the electricalsteel property data and the proposed design procedure, it ispossible to design durable IPM motor rotors that can last muchlonger than the expected lifetime of an EV/HEV vehicle

Notes:

Vendor supplied data

Publisher Number:

2010-01-1308

Access Restriction:

Restricted for use by site license