Bonded versus Sintered Interior PM Motor for Electric and Hybrid Vehicles

Transcription

1 ! "# " Bonded versus Sintered Interior PM Motor for Electric and Hybrid Vehicles A. FONSECA and Ch. CHILLET ICEM 2002, Brugge, Belgium, August 2002

2 $ # Objective Comparison of Bonded and Sintered IPM Motor for Electric and Hybrid Vehicles Approach Finite Element Method Non-linear modeling Design of Sintered and Bonded IPM motors Efficiency map for various drive cycles Comparison of consumption, cost and losses Results Bonded IPM performs better against Sintered IPM Cost of Bonded Magnet need to be reduced Suitable for high-speed driving cycles only

3 % & $ ' Electric Vehicle (EV) Electric Motor Rechargeable battery Hybrid electric vehicles (HEV) Electric motor Internal Combustion Engine (ICE) Battery and On-board Generator

4 (!! Very low emission Cost reduction Energy efficient On-board power generation smooth operation Appropriate Propulsion

5 )! * & # +) *, Synchronous Motors with Permanent Magnet (PM) inside the rotor, characterized by: Higher efficiency Increased torque capability higher power density Variable speed operations

6 ) * - # PMSM performance depends on Power loss components Peak power Continuous power Speed ratio Magnetic core Saturation Magnetic flux harmonics

7 ! Neodymium Iron Boron (NdFeB) Samarium Cobalt (SmCo).

8 *.! Sintered Magnet Sintered Magnet High energy product (50 MGOe) High temperature range (>180 C) Bonded Magnet Bonded Magnet! No machining required better resistance to corrosion

9 " / +/,! $ Division of machine cross section into finite elements Interpolation function represent the variation of flux density over the elements Matrix equations with boundary conditions Linear or nonlinear, algebraic or differential equation solution

10 # $ 0 (! & Standardized driving pattern (Velocity-time diagram) for test procedure Used for consumption and performance estimation Typical highway Driving Cycle

11 %!&'$! & 1 Four Test m/c Bonded IPM " Reference m/c Sintered IPM " Result Bonded Vs Sintered Estimation Stator current Energy distribution Comparison PM volume, Cost Selection Best Bonded IPM Model Estimation Current, Voltage, Efficiency

12 %!&'! * Nonlinear reluctance network using FEM Cross magnetization effect considered Magnetic saturation effect considered Steady state model using fundamental flux FLUX2D software used Works for Surface, Inset of Interior motor New coupled eqv. circuit

13 %!&' 2 Mechanical losses Neglected Copper losses Coil resistance at C measured I 2 R loss calculated using Torque-Speed map Core losses Simplified analytic formula x y Z Pcore (B,) = (K[aB + bb ] + B Fundamental load flux K,K C,X Calculated experimentally K c )

14 %!&' # 3 Electric consumption Electric Consumption where,k ri = 1 ( ) Electric consumption i i n = i= 1.. Inverter current Power electronics cost Magnet volume Machine cost Cost_ind = C Irms + C Vol IRMS MAX i i PM t k. ri PM

15 %!&'# * ) Sintered magnet in double layers Reduced high-speed core loss Flux weakening capability Reduced inverter current

16 %!&'#. ) 4 Designs (IPM A,B,C,D) Only PM arrangement varied Used for higher power rating than normal PM volume and maximum phase current

17 %!&'! # Cost indicator for 4 Bounded motors compared to Ref motor Current/ Voltage evolution of IPM C compared to Ref motor City Around Highway NMVEG City +3.2% - 0.9% - 2.6% - 0.4% Total machine losses Driving cycle consumption

18 %!&'! # 4# Bonded Magnet IPM better for: Flux weakening mode operation Lower phase current Higher efficiency However: Suitable for high speed operation Cost of Bonded Magnet need to be one-third of Sintered Magnet

19 % FEM Model of PMSM Only steady state model used Only fundamental load flux considered Loss Estimation Model Resistance at average temperature (180 0 C) Core loss estimation used analytic equation Cost Model Inverter current as indicator of power electronics cost PM volume as indicator of motor cost cost of Bonded PM is one-third of Sintered PM

20 %(! 5 # # 6 Details of Bonded IPM machines (geometry, configuration, ratings etc.) Effects of using Bonded IPM at an elevated power rating Dynamic behavior and relevant performance and cost variation

21 %! # 3 * / # 7 FEM modeling, loss estimation and cost & consumption analysis indicate prospects of using Bonded IPM motor in EV and HEV. However, further research is needed to study Dynamic performance of motors Comprehensive cost model Search for low cost, high quality magnets Consumption of other driving cycles

22 / #! Edward P. Furlani, Permanent Magnet and Electromechanical Devices, ISBN