more electric aircraft 000

8/3/2019 More Electric Aircraft 000

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The More EleThe More Ele

Why Aerospace NeeWhy Aerospace Nee

Prof Pat

University of Notting

Tel. +44 (0) 115 951 5591 Emai

ctric Aircraftctric Aircraft

s Power Electronicss Power Electronics

Wheeler

am, Nottingham, UK

l. [email protected]


2/24

IntroductionIntroduction

l The More Electric Aircraft aof a more energy efficient air The More Electric Aircraft con

History of more electrical sys

Motivations and systems

l Regeneration onto the Aircraf Power converters and actuati

Benefits and issues

Potential solutions

Simulation results

l The next steps The Clean Sky JTI project

step in the directionraftept

ems in Civil Aircraft

t Power Systemn systems


3/24

Power SourcesPower Sources Conventional Airc Conventional Airc

Jet F

Electrical

Gearbox driven

generators

High pressure

air bled from

engine

Pneumatic200kW 1.2MW

Total non-thrust

raftraft

el

Propulsion

Thrust (

40MW)

Gearbox driven

hydraulic pump

Hydraulic

Fuel pumps

and oil pumps

on engine

Mechanical240kW 100kW

power

1.7MW


4/24

Electrical Avionics Cabin (lights, galley, in-flight entert Lights, pumps, fans 115V, 400Hz AC

Pneumatic Cabin pressurisation Air conditioning Icing protection

Hydraulic

Flight control surface actuation Landing gear extension/retraction a Braking Doors

Mechanical Fuel and oil pumps local to engine

Power SourcesPower Sources Conventional Airc Conventional Airc

inment etc)

d steering

raftraft


5/24

More Electric Aircr More Electric AircrConceptConcept

Engine

gener

Existing electrical

loads

Electrical syste

Rationalisation of

power sources and

networks

Bleedless engine

ELECTRICAL

Cabin pressurisation

Air conditioning

Icing protection

J

ftft

Expanded electrical network

driven

tors

power 1MW

New electrical loads

ELECTRICAL

light control actuation

Landing gear/ Braking

Doors

ELECTRICAL

Fuel pumping

Engine Ancillaries

t Fuel

Propulsion

Thrust ( 40MW)


6/24

More Electric Aircr More Electric AircrSome MotivationSome Motivation

l Removal of hydraulic system reduced system weight

ease maintenance

l Bleedless engine

improved efficiency

l

Desirable characteristics of electr controllability

power on demand

re-configurability

maintain functionality during fault

advanced diagnostics and progno

more intelligent maintenance

increased aircraft availability

l OVERALL

Reduced operating costs

Reduced fuel burn

Reduced environmental impact

ftft

ical systems

s

tics


7/24

More Electric AircrMore Electric Aircr

l Airbus A380 4 x 150kVA Wideband VF on turb

Flight Control Power 2 H + 2 E

Actuator Configuration

Combination of Hydraulic and Ele

ftft

fan engines

ctrical Actuation


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l Vickers VC10 Electrical System 4 x 40kVA Ge

Flight Control Power 2 H + 2 E

Actuator Configuration

Combination of Hydraulic and Ele

Built 50 Years before the Airbus

ftft

nerators

ctrical Actuation380


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l Boeing 787 4 x 250kVA Primary Channel Star

500kVA per channel

230VAC VF Primary Power Gener

Electrical Starter/Generators rate

Electric ECS, pressurisation and

Removes need for bleed air from

S/G6 S/G5

S/G1

Electrical Power Distribution System

S/G4 S/G3 S/G2

230 VAC

3-Phase

VF

230 VAC

3-Phase

VF

230 VAC

3-Phase

VF

250kVA 250kVA 250kVA 250kVA

225kVA 225kVA

230 VAC

3-PhaseLoads

115 VAC

3-PhaseLoads

28 VDC

Loads

ftft

ter Generators

tion

at 250/225kVA

ing anti-Icing

engines


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More Electric AirMore Electric Air

l Joint Strike Fighter 270V DC Power System

Electric actuation systems

80kW, 2 channel, switched reluct

Reduces cost, size and weight of Relies on Power Conversion tech

Harsh environment

Efficiency

Reliability

raftraft

nce generator

whole aircraftologies


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More Electric AirMore Electric Air

A Possible MEA DC PSource: Virginia Polytechnic

raftraft

wer System Layout


12/24

Typical Power LeTypical Power Lefor Electrical Lofor Electrical Lo

Power User

Air Conditioning ECS

Flight Controls Primary an

Fuel pumps

Wing Ice Protection Thermal m

Landing Gear Retraction,

Engine starting May be us

application

velsvelsdsds

omments Typical Powe r

level

4 x 70kW+

secondary 3 kW to 40kW

often shortduration at high

loads

about 10kW

ts or similar 250kW+

steering and braking 25kW to 70kWshort duration

d for additional 200kW+ short

duration


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AC Power GenerAC Power Gener

l Mechanical Constant Fre

Mechanical gearbox createvariable speed input

Constant speed shaft drive

Voltage control used for t

400Hz voltage supply fi

Expensive to purchase and

Single source due to pate

Constant SpeedMechanical Drive

[Gearbox]

ConSpeeVariable speed

Engine Shaft

tiontion

quency Gen. [traditional]

a constant speed shaft from a

s the Generator

e generator

ed frequency

maintain

nts

Generator

tantShaft

3-phase

400Hz, 115V


14/24

AC Power GenerAC Power Gener

l Variable Frequency Gen

Generator provides variabl

Voltage control around ge

Direct connection between

Simple and reliable gener

Nearly all aircraft loads wilfor control

Good News for Power Ele

GeneratorVariable speed

Engine Shaft

tiontion

ration [new aircraft]

frequency supply

nerator

generator and power bus

ation

l require power converters

tronics Engineers!

3-phase320Hz to 800Hz

230V or 115V


15/24

Actuation SystemActuation System

Elimination of hydraulics Electro-Mechanical Actuator 30kW matrix converter integrated with ballscrew housing/heatsi

Holistic design of motor/load/power con

Maximise system efficiency Minimise system weight

Advanced thermal management Copes with intermittent operation

Example of an Actuation System

Matrix

Converter

PM

Motor

Control

Ram Position

250Hz sampli2Hz bandwid

Motor Current12.5kHz sampling rate200Hz Bandwidth

Motor Speed1.25kHz samplin20Hz bandwidth

Supply360Hz to

800Hz

ResolverLEMs

SupplyVoltage

Ram Position Demand

Voltagetransducers Filter

ss

nk

verter

Actuator

ing rateth

g rate

LVDT


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Regeneration: ConvRegeneration: Conv

3-PhaseSupply

3-Phase

Load

Energy dissipationin the DC Link

Traditional Solution:

DC link chopper and resistor in DC link usedto dump regenerative energy

Lowers system efficiency and increase sizeand weight of equipment

Measure DC link voltage and operatechopper when DC link voltage above a setlevel

Resistor and associated cooling can double

volume and weight of the power converter

rtersrters

3-phasesupply

Bi-directional

switch

Load

Long Term Solution:

Allow regeneration onto aircraft powersystem

Use a Direct [Matrix] Converter or acontrolled rectifier

Energy returned to supply giving a smaller,

lighter power converter


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Motor Speed ReveMotor Speed Reve salsal

Motor shaft speed (rpm)

q-axis current

Phase A current

Phase B current

Phase C current

Torque (Nm)


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Motor Speed ReveMotor Speed Reve

REGENERATION

salsal

Motor shaft speed (rpm)

q-axis current

Phase A current

Phase B current

Phase C current

Torque (Nm)


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Options for RegenerOptions for RegenerEnergy ManagemEnergy Managem

l Regeneration will save conside

Regenerative energy must be hPower Quality

l Eight methods have been identelectrical regenerative energy

Centralised Energy Storage

Centralised Energy Dissipation

Local Voltage Control

Return Energy to Source

Separate Bus for Regenerative

Local Energy Dissipation

Local Energy Storage

Hybrid Structures with Local Di

tivetiventnt

able weight and volume

andled correctly to maintain

ified for safeanagement

Energy

sipation

Options for RegenerOptions for Regenerativeative


20/24


Local Energy Dissipati

Generator

BusControl

Control Recovery Ad

Local to load No Exist

do not allow regeneration onto theaircraft bus

ensure that each item of equipmentenergy dissipation if required

todays solution

ativeativentnt

n existing solution

Converters

Regenerative

Loads

Energy Dissipation

eg. Resistor with breakchopper

antages Disadvantages

ing solution Size and weight ofequipment, sub-

optimum system design

as

Options for RegenerOptions for Regenerativeative


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Return Energy to SourControl Recovery A

Centralised Yes No lahard

Generator

Bus

EnhancedControl

allow regeneration onto the aircra

use the generator as a motor if re

the regenerative power would be

only possible if there is no auxiliar

ativeativentnt

evantages Disadvantages

rge additionalware

Possible change toexisting generator

control methods

Converters

RegenerativeLoads

t bus

uired

eturned to the engine inertia

y gearbox


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Impact of RegeneraImpact of Regenera

Modelling study performed in SABER

Sudden change of total actuator power from40kW motoring to -55kW regeneration

Simulation for given for a fully preloadedgenerator

voltages at HVAC Bus 230V and at AC Bus 1are kept within the envelopes according to MSTD-704F

tiontion

5VIL-

Generator Torque

reduces

MIL_STD-704F envelope

for transients


23/24

ConclusionsConclusions

Power Electronics can offer adapplications

System efficiency,

Size and weight

Flexibility

There are challenges for Poweenvironment

Losses

Reliability

Integration

Future projects will take these

antages in aerospace

Electronics in this

area forward


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Clean SkyClean Sky

l Total project budget 1.6B Duration 7 years

l Clean Sky JTI work is split into sixITDs

l Led by 12 companies [Members] Thales, Liebherr, Airbus, Dassualt, Alenia,

SAAB, Rolls Royce, Safran, EADS, .

l Each ITD then has 5 or 6 otherorganisations [Associate Members]

l 25% of funding reserved for Callsfor Proposals

See www.cleansky.eu now for first calland get involved

JTIJTI

l The University of Nottingham is anAssociate member

Systems for Green Operations ITD

We are the only University which is anAssociate Member in our own right

Budget of about 10M
http://www.cleansky.eu/

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