eea 2004 - j3ea

EEA 2004 - EYAE - Ref. X24PR0401420 - Issue 1

18th March 2004

EEA 2004From the More Electric Aircraft to the All Electric Aircraft:

State of the Art & Prospective

ELECTRICAL DEPARTMENT

Presented by

Olivier LANGLOISEtienne FOCHXavier ROBOAMHubert PIQUET

Thursday 18th March 2004EEA 2004 - EYAE - Ref. X24PR0401420 - Issue 1 Page 2

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Plan

Introduction

1. Hydraulically Powered Aircraft

2. More Electric Aircraft

3. Towards All Electric Aircraft

4. Example of DC Network

Conclusion


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Introduction


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Current project POWERNET

• Powernet is a RTC about electrical power

• LEEI (Toulouse)

• 3 topics are studied:Power managementMethods of network conceptionHigh voltage DC network

Electricity involve a lot of changes


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Airbus has the most modern aircraft Family


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1. Hydraulically Powered Aircraft


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Users: Engine off-takes needs for aircraft users

Mechanical power- Engine Fuel Pump- Engine Oil Pump

- Engine start200kW (peak)

100kW (local)

Hydraulic power- Flight Controls- Landing gear- Braking- Reverse- Doors

240kW-206bars

Electrical power- Avionics- Commercial- Pumps- De-icing- Lights- …...

115VAC-230kVA

Pneumatic power- Air conditioning- Pressurisation- Ice Protection

- Engine start

From some barsup to 20bars-1200kW

Example: Power used on A330

Power rationalisation should be feasible

4 Power source types3 Power networks on aircraft


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General Overview of an aircraft electrical network

AC/DC Conversion

Batteries

Main Generation AC

DC distribution : 28VDC

AC distribution : 115VAC


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A330: General Architecture (3H)

IDG 1PumpPump

AccuAccu

RATRAT

AccuAccu

CSM/GCSM/G

TR 1TR 1

AC BUS 1 AC BUS 2

AC ESS BUS

ESS TRESS TR

STAT INV

DC ESS BUS

DC BUS 1 DC BUS 2

IDG 2Pump

AccuAccuEXT

Engine 1 Engine 2

TR 2TR 2 APU TRAPU TR

APU START

PumpPump PumpPump

APUGENAPUGENBlue Green Yellow

BAT 1 BAT 2

H2 H3H1


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2. More Electric Aircraft


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A380 Novelties

Generator: VFG (150 kVA) replace IDG (≤ 115 kVA)

Variable frequency (f = 360…800 Hz) replace Fixed frequency (400 Hz)

Electrical actuators (EHA…) replace Some hydraulic actuators

Electrical RAT replace Hydraulic RAT

AC-DC Converter: BCRU (300 A) replace TRU (200 A)

Electronic circuit breakers (up to 15 A) replace Thermal circuit breakers


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A330 “A380”: General Architecture (2H+2E)

VFG 1 PumpPump

AccuAccu

BCRU 1BCRU 1

AC BUS 1 AC BUS 2

AC ESS BUS

BCRU ESSBCRU ESS

STAT INV

DC ESS BUS

DC BUS 1 DC BUS 2

VFG 2Pump

AccuAccuEXT

Engine 1 Engine 2

BCRU 2BCRU 2 APU TRAPU TR

APU START

APUGENAPUGEN

Green Yellow

RATRAT

BAT 1 BAT 2

BAT ESS

E1 E2

H1 H2


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AC Main Generation

IDG

CSD45

00…

9000

tr/m

in

2400

0 tr

/min

PMG Exciter Main

NS

NS

1200

0…24

000

tr/m

in

VFGPMG Exciter Main

4500

…90

00 tr

/min

NS

NS

On A380, IDG has been replaced bya Variable Frequency Generator (VFG) which is conventional wound rotor synchronous alternator

The frequency range is 360-760Hz

Variable Frequency Choice

Mechanically simpler AC source

Butextra-constraints for users


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AC Main Generation

On A380, IDG has been replaced bya Variable Frequency Generator (VFG) which is conventional wound rotor synchronous alternator

The frequency range is 360-760Hz

Variable Frequency Choice

Mechanically simpler AC source

Butextra-constraints for users

IDG A320 90 kVA


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Users : Exemple of electrical flight control

ServovalveAccumulator

Modeselectordevice

Ram

Manifold

Electro-hydraulicservocontrol

Modeselectordevice

Ram

Manifold

Electronics

Motor

PumpAccumulator

Electro Hydrostatic Actuator

EHA are used on A380replacing

one of the 3

hydraulic networksby EHA

supplied by the

electricalnetwork


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Electrically Powered Actuators

EHA supplied by AC power:

EHA Motor

Melec.

EHA Pump

Phyd.

EHA Rectifier EHA Inverter

Bleed Resistor

Hydraulic Jack

Flight Control

115/

200

V A

C

Filter Capacitor

EHA

270 V DC

⇒ Higher local weight but lower global weight


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Electrically Powered Actuators (cont’d)

EHA Bond Graph

• Multi-domain representation• Good visualization of power transfers

Aerodynamic effortDC power supply

Ubus

Ibus

E : « effort » variable

F : « flow » variable

Se : Ubus TF1/α U

I1

E

IGYΦ Cem

Ω

I : L

R : R

1

I : J

R : f

Cch

ΩTFD Pp1-Pp2

Qpi

0Qp

R : 1/ αη

Qfp

Pp1-Pp2 1

Pv1

Qp

0Qv

Qfv

Pv1 TF

R : 1/Cvh1Qfv

Qfv

Pv1-Pv2

Pv1

Pv2

1

2ch

h SBV

2/R1 : C

⋅=

0Qv

Pv2Pv2

Qp

1

2ch

h SBV

2/R1 : C

⋅=

2p

: S bloce

2p

: S bloce

Pp1

Pp2

Qp

Qp

1/S

TF1/S

Fv1

Fv2

Vv

Vv

Fv’

Vv

0

C : 1/Rm

FT=Fv’

VT

1

Se : Fservo h

FG

VG=VT

1

FM

TFMG

ΩG

1/BlSe : MG

Converter Electrical motor Hydraulic pump Pipes Hydraulic jack Control surface

2G

BlJ

M : I =

Fv

Vv

1

Se : Fsec v

Transmission

R : 1/Cvm


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AC – DC Converters

TR

ATRU

28 V

DC

115/

200

V A

C

BCRU

28 V

DC

115/

200

V A

C

270

V D

C

Buck

• BCRU is used to provide 28 V DC and to charge battery• Batteries are permanently connected to the DC network


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3. Towards All Electric Aircraft


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Next step : Main Generation for more needs

Power available versus Aircraft Weight

0100200300400500600700800900

1000

0 200 400 600 800

Max Aircraft Weight MTOW (tons)

Pow

er a

vaila

ble

(kVA

)

Power rationalisation is rather oriented towards more electrical systemsCommercial need is also a factor of power demand increase

A380

7E7

Current aircraft

Next aircraft generation showsa strong break in power demand versus current certified one’s

Thus more electric aircraft needs induced High probability of voltage change either 230 V AC or HVDC⇒ Probability of standard change

A new standard change will impact airlines, industry and technology


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“Bleed” Removal

APU

Engine

Bleed Air

Elec

Air

Engine start

Elec

Air systems

Gen

Gen

Bleed

Electrical loads

Current configuration


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“Bleed” Removal (cont’d)

APU

Engine

Bleed Air

Elec

Air

Elec

Air systems

Gen

Gen

Bleed

Electrical loads

Engine start

Without bleed air configuration


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POA: An Innovative Integrated Generation

Goodrich – 150 kWFan-Shaft GeneratorSwitched reluctance

Power Optimised Aircraft

Energy optimisationVoltage: 350 V DC

HP Starter/GeneratorPermanent magnet

Thales AES150 kW


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Next steps – More versatile users

Electronics converter are largely used even for huge loads

10% motors are fitted with a power electronics on A3456

70% for A380

Other technical loads (eg: light, heating, …) and commercial loads used power electronics as well

Fans/Pumps/Actuators number versus power

0

10

20

30

40

50

2500

5000

7500

1000

012

500

1500

017

500

2000

022

500

2500

027

500

3000

0

Power (VA)

Mot

or(>

1kVA

) nu

mbe

r

A380A3456

The number of power electronic users increases drastically on AirbusPower system specialists take more and more benefits of electronics technologies

for their advanced system architecturesVery huge loads are expected for other programs around 100 kWMore than 100 motors (>1 kVA) for technical loads on A380


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Other Electrical Systems

Great loads use power electronics

• Electrical actuators (for flight controls):EHA, EBHAEMA

• Fan, compressor, pump…

• Example: Electrical Flaps, more electrical architecture

Motor

Motor


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4. Example of DC Network


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Emergency Generation

RATRAT

AIR FLOW

AIR FLOW

An emergency source (called RAT) powered by the air flow

The RAT drives a hydraulic pump which supplies a small electrical generator (less than 10kVA)

On A380, the RAT drives an electrical alternator

In the future, other sources are possible:fuel cells, super-capacitors…


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Emergency Network

RAT Rectifier Inverter

MSMS

Filter NetworkRAT

Batteries,Super-capacitors…

Storage converter

115/200 V400 Hz

Storage element

Accumulationof energy when low needs on network

Restitutionof energy when high needs on network

Use of 2 different sources:• RAT as an energy source• Storage element as a power source


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Energy Recovery

• EHA normally supplied by AC network• Storage element on the DC bus

EHA Rectifier EHA Inverter EHA Motor

Mélec.

EHAPump

Phyd.

EHA

Batteries,Super-capacitors…

Storage converter

Storage elements

Mai

n ne

twor

k11

5/20

0 V

AC

Storage system

Emer

genc

y ne

twor

k27

0 V

DC


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Main Network in DC

• Most of systems own power electronics

• Stability trouble

• New network architectures

Rectifier EHA Inverter

MS

EHA MotorGenerator

270 V DC

Mélec.

EHA Pump

Phyd.

EHA without rectifierPower Generating System


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Conclusion


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Open discussions

•• The more electric aircraft is a general trendThe more electric aircraft is a general trend

•• There is more and more power electronicsThere is more and more power electronics

• Should aircraft manufacturer switch to HVDC?

• What are the best auxiliary sources to replace APU, RAT…?

• Which sizing methods could we use to make the right choice?


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Ce document et son contenu sont la propriété d’AIRBUS FRANCE S.A.S. Aucun droit de propriété intellectuelle n’est accordé par la communication du présent document ou son contenu. Ce document ne doit pas être reproduit ou communiqué à un tiers sans l’autorisation expresse et écrite d’AIRBUS FRANCE S.A.S. Ce document et son contenu ne doivent pas être utilisés à d’autres fins que celles qui sont autorisées.

Les déclarations faites dans ce document ne constituent pas une offre commerciale. Elles sont basées sur les postulats indiqués et sont exprimées de bonne foi. Si les motifs de ces déclarations n’étaient pas démontrés, AIRBUS FRANCE S.A.S serait prêt à en expliquer les fondements.

eea 2004 - j3ea

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