Transcript Ipm motor drives for hybrid electric vehicles

By,
LINSS T ALEX
Edited By
Sarath S Nair
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INDEX
 Introduction
 Modeling
of IPM machines
 Analysis of IPM motors
 Rotor Design Topologies
 Performances
 Applications
 IPM motors in Hybrid Electric Vehicles
 Conclusions
 References
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INTRODUCTION
 HEVs are gaining increased attention due
to their higher efficiencies and lower
emissions.
 HEV combines a smaller IC engine with a
battery pack and an traction motor to drive
the vehicle.
 Requirements of traction machines
include high efficiency and high
performance.
 An Interior Permanent Magnet(IPM)
synchronous machine is used to obtain
mechanical robustness,capability of flux
weakening and high speed operation.
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A one pole pitch cross sectional view of a
6-pole IPM machine with tangential magnet
configuration

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1.MAGNETIC MODEL
Average air gap flux density,
CØ=Am/Ag, flux concentration factor
Br- Remanence of the magnet
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Also,
Parameters of above equations,
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g-air gap length
Kc-Carter coefficient
μrec -relative recoil permeability
Amm=t.l, cross-sectional area of the iron bridge
above the nonmagnetic barriers .
t - Bridge width
l-motor stack length.
Bs-limit of leakage flux density in the bridge due to
saturation.
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Maximum value of first harmonic of the PM flux
linkage,
Kwl-winding factor
Nph-winding turns per phase
P-number of pole pairs
α-pole arc to pole pitch ratio
D-inner diameter of stator
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The d-axis and q-axis inductances,
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Where Kd and Kq are defined as,
ge- effective air gap,
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2.ELECTRICAL MODEL
Flux distribution in the air gap is assumed to be
sinusoidal and the iron loss and magnetic
saturation are not considered.
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From the motor vector diagram voltage
equations are,
The motor torque,
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 id
and iq are the d-axis and q-axis
components of stator current vector Is.
 Magnitude of stator current vector is,

The design optimization is carried out under
the condition of maximum torque per
Ampere control
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Flux linkage and inductances can be
normalized as,
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 IPM
motor is an induction start but
synchronously run high efficiency motor.
 IPM must overcome the magnet brake
torque during starting process.
 Developed power Pd is,
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 In
IPM motors inserting permanent magnets in
various arrangements and magnet polarity
orientations below the conduction cage of the
IPM rotor .
 An IPM motor develops driving torque due to
both permanent magnet excitation and
reluctance variation.
 Developed torque Td is,
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 First
term is permanent magnet excitation torque
component.
 Second term is reluctance torque component
 Efficient utilization of reluctance torque
component is most critical for intensive flux
weakening operations and efficiency
improvements in HEV and electric traction drive.
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NdBFe magnets having high B and very large H is
used for rotor design.
 Two types 1)Straight type 2) V-type
 Straight type has buried permanent magnet
materials

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
V shape rotor with permanent magnets having
polarity arrangement without conduction cage for
optimum air-gap flux is used in HEV and traction
application.
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Torque to weight ratio significantly improved by
operating the IPM motor at 650-Vdc from smart
dc-dc converter.
 The light load loss decreased primarily by
employing high-grade silicon steel.

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
3-phase,4-pole,Y-connected,200V 1 hp IPM motor
with NdBFe magnets comparing with a .6kW,3phase,4-pole,200V induction motor
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The efficiency and power factor as well as their
product of the IPM motor is over 35% better than
that for identical rated induction motor.
 The energy efficiency aspect is a key factor for
wide spread high performance applications of IPM
motor drives.

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Ventilation fans
 Air conditioner/heat pump compressors
 Cranes
 Lift/escalators
 Blood pumps
 Ship propellers
 Electric locomotive traction drives
 Electric and Hybrid Electric Vehicles

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 IPM
motors provides wider torque-speed range
under severe size, weight and cost constraints.
 IPM motors fulfill the requirements for smooth
vehicle propultion,low vibration/noise and high
degree of driving comfort.
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Low Speed
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Cruising
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Braking
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
At 650V level, a new reduction gear is
incorporated for further reduction in axle torque to
about 50%,thereby reduce motor size significantly.
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Modeling and analysis of IPM machines were
discussed.
 Rotor design features for specific applications
was studied.
 Comparative performances of IPM and induction
motors was discussed.
 Several examples of successful applications were
high lighted.
 High performance IPM motors have emerged as
the choice of energy efficient and environmentally
friendly Hybrid Electric Vehicles.

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[1] M.A.Rahman, “Permanent Magnet Synchronous Motor-A review of
Design Art", Proceedings of International Conference of Electrical
Machines-ICEM’80,Athens,Greece,Sept.15-17,1980,pp.312-319.
[2] M.A Rahman,T.A.Little and G.R Slemon, “Analytical Models for
Interior-Type Permanent Magnet Synchronous Motors”,IEEE
Transactions on Magnetics,vol.MAG-21,No.5,1985,pp.1741-1743.
[3] M.Kamiya, “Development of Traction Drive Motors for the Toyota
Hybrid System”,Proc.IPEC-2005,Niigata,Japan,April 4-8,2005,pp.14741481
[4] T.M.Jahns, G.B.Kiliman and T.W.Neumann, “Interior PM Synchronous
Motors for adjustable Speed Drives”, IEEE Transactions on Industry
Applications,vol.23,No.4 1987,pp.681-689
[5] M.A Rahman, “IPM Motor Drives for Hybrid Electric Vehicles”,IEEE
Transactions 2007.
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[6]
L.Chang,”Comparison of ac drives for electric vehicles-A report on
experts opinion survey,” IEEE AES System Magz. Pp.7-10,Aug.1994.
[7]
Arash Hassanpour Isfahani and Siavash Sadeghi, “Design of a
Permanent Magnet Synchronous Machine for the Hybrid Electric
Vehicle”,IEEE Trans.vol.45,pp.566-570,Dec 2007
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