bailey m deer conf 2000

7/27/2019 Bailey m Deer Conf 2000

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Electrically-Assisted Turbocharger Development

for Performance and Emissions

Milton Bailey, Leon Tolbert, Norberto Domingo-ORNL, andBrian Bolton, Nabil Hakim - DDC

Turbocharger transient lag inherently imposes a tradeoff between a robustengine response to transient load shifts and exhaust emissions. By itself, a well-matched turbocharger for an engine has limited flexibility in improving thistransient response. Electrically-assisted turbocharging has been seen as anattractive option to improve response and lower transient emissions.

This paper presents the results of a multi-year joint CRADA between DDC andORNL. Virtual lab diesel simulation models characterized the performanceimprovement potential of an electrically assisted turbocharger technology.Operating requirements to reduce transient duration between load shift time byup to 50% were determined. A turbomachine has been conceptualized with anintegrated motor-generator, providing transient burst boost plus energy recoverycapability. Numerous electric motor designs were considered, and a prototypemotor was developed, fabricated, and is undergoing tests. Power controls havebeen designed and fabricated.


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Electrically Assisted Turbo-Charger Development for Performance and

Emissions

Summary of CRADA # 1996-2000

Detroit Diesel Corporation,

Oak Ridge National Laboratory

Presented byHoushun Zhang, Detroit Diesel Corporation

Milton Bailey, Oak Ridge National Laboratory


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999 Detroit Diesel Corporation. All Rights Reserved.

Outline

Motivation Transient Engine Operation Engine & Turbocharger Matching

Transient Engine & Turbocharger Modeling Potential Improvements Comparison of Results

Electric Machinery Power Electronics Status of Tests


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Motivation

Turbo Critical for Power density, Fuel economy,Emission and Driveability.

Response Time during Transient Operation due toTurbine inertia.

Improve driveability Reduce engine smoke and high PM Turbocharger Technology is a Key to Emission

Reduction.


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HD FTP Transient TestTransient Engine Operation

1st Quarter

-1000

0

1000

2000

3000

500 1000 1500 2000 2500

Engine Speed, rpm

Transient Engine Operation3rd Quarter

-1000

0

1000

2000

3000

500 1000 1500 2000 2500

Engine Speed, rpm

Transient Engine Operation2nd Quarter

-1000

0

10002000

3000

500 1000 1500 2000 2500

Engine Speed, rpm

Transient Engine Operation4th Quarter

-1000-500

0500

10001500

20002500

500 1000 1500 2000 2500

Engine Speed, rpm


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FTP 3rd Quarter Operation

-5000

500

10001500

2000

2500

500 1000 1500 2000 2500Engine Speed, rpm

HD FTP Transient Test


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HD FTP Transient TestTurbo Response

TRANSIENT TURBOCHARGER OPERATION

0

20000

40000

60000

80000

100000

120000

360 400 440 480 520 560 600

Cycle Time (s)


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Turbochargers in Emissions Perspective

33

0.600.60

P M

g / h p

P M

g / h p - - h h

NoNo xx g/hpg/hp --hh

11

0.100.10

0.050.05

0.250.25

22 2.52.5 44 55 66

1991

1988

19941998

20072007

VGT + ? VGT + ?

Free Floating

Wastegated

2002

VGT


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Electrical Turbo Assist

Photo/Description of Prototype

O RN L - 1994 Sk e tc h

Externally drive

turbocharger duringtransient Improve emission &

performance at cost of BSFC

Potentially Use Motor for Steady State BSFCImprovement.


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Technical Approach- Virtual Lab

Baseline Engine

Evaluate Concept with ElectricallyAssisted Turbo

Design Recommendations

Evaluate Virtual Engine

Build Hardware

Meet

Targets?

YES

NO

Experience plays a big role


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Baseline Engine During Transient Run

Turbo Speed vs. Time

Time [s]

SimulationData

Simulation within 1% of Testing Data


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Simulated Baseline TransientTurbocharger Operation

Objective:

up to 50%reduction in turbospool-up time

What is the Motor

Requirement?

0

2

4

6

8

10

12

14

0 1 2 3 4

Elasped Time (SEC)

T u r b o

N e t

P o w e r

( K W )

0

20000

40000

60000

80000

100000

120000

T u r b o

S p e e

d ( R P M )

Baseline Engine


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Ramp Acceleration Time for Two Typical Motors

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

0 5 10 15

Motor Shaft Power (kw)

A

c c e

l e r a

t i o n T

i m e

( s )

CONSTANT TORQUE

CONSTANT POWER


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Technology Comparisons Using Virtual Lab

10 HP Power Assist Gives 17% Reduction of Response

1800 RPM Load-Acceptance Test

0 1 2 3 4

Elasped Time (s)

Engine Data

10 HP15 HP20 HP


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Electric Motor Design Goals : 10hpconstant 20k-100k rpm Motor/alternator options considered included

Permanent magnet vs switched reluctance Axial gap vs radial gap

Permanent magnet, radial gap, two-pole designselected, 1997. High power density and efficiency Low polar moment of inertia

Shaft diameter can be larger Facilitates design for high speed Disadvantage is larger stator diameter


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Electric motor major components


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Preliminary motor performance resultsRadial-Gap PM Turbomotor Power Test Data

0

1

2

3

4

5

6

7

8

9

0 10000 20000 30000 40000 50000 60000 70000

Speed,rpm

I n p u

t P o w e r ,

k w

low

high


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Concluding Remarks

Electric Assisted Turbo is One of Promising

Technologies to Achieve Fast Response. Motor & sensorless controller conceived, designed

and developed.

Demonstration hardware has been built and earlyvalidation achieved. Design enhancements have been identified which

should lead to a more robust design.


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Acknowledgements ORNL additional team members - Norberto Domingo, Leon

Tolbert, Wayland Blake, Bill Allington, Gui-Jia Su Detroit Diesel Corporation additional team members -Tim Prochnau, Craig Savonen, Nabil Hakim

Sponsor - DOE/NE, Dr. Bill VanDyke

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