The Science powering Clean Sky 6/3/2016

Development of Dynamic Phasors for the Modelling

of Aircraft Electrical Power Systems

Tao Yang, Serhiy Bozhko, Greg Asher, Pat Wheeler

The University of Nottingham

- Within Clean Sky SGO WP2.4 and WP2.3.0.7

Nottingham

Manchester

Liverpool

London Bristol

180km

City of Nottingham

Population 300,000

The city famous for the legend of

Robin Hood and Brian Clough

[one time manager of the

Nottingham Forest football team]

Nottingham

•

PEMC Group & My PhD

Main campus UK

Power Electronics, Machine and Control Group - A world leading research group

Aerospace (More Electric Aircraft)

• Future electricity networks

• Renewable energy

• High-energy physics applications

• Automotive, marine and industrial applications

Application Areas

Underlying scientific research

• Power device packaging and cooling

• New actuator topologies

• New cooling methodologies & thermal integration

• New modelling methods

• High density power converters for power distribution,

actuator drives, ECS etc.

• Aircraft electrical power systems (AC/DC/Hybrid)

• Advanced actuator designs

• Solid state switching (fault isolation, re-configuration)

• Diagnostics and Prognostics (system and device level)

• Electromagnetic compatibility and wireless systems

More-Electric Aircraft Research Themes:

2,200m2 laboratories with own 1MVA supply

Motor rigs 1kW to 750kW, voltage supplies to

13kV

Electrical Machine/Actuator manufacture

Machine and Power Systems testing to 800kW

Environmental testing chambers

Facilities for multi-layer power plane, surface

mount & FPGA

Aircraft Electric Power Systems Validation

Infrastructure

Group Facilities

> 120 Researchers/Academics

45 Contract Research Fellows

75 PhD students

4 Visiting Scholars

Electrical and

Electronic

Engineering

Mechanical,

Materials and

Manufacturing

Engineering

Engineering Faculty

Applied

Optics PEMC

Group

Institute

Electro-

magnetics

Heat

Transfer

Research

Research Council

29%

European Commission

33%

Knowledge Transfer

Partnerships

15% Industry

16% TSB/Industry

4%

Overseas Industry 4%

Current Research Grants ‎€ 34M EURO

16 Academic Staff

6 Full Professors

3 Associate Professors

7 Assistant Professors (I am here)

Power Electronics, Machine and Control Group - A world leading research group

Dynamic Phasors Modelling of Aircraft Electrical

Power Systems

• More-Electric Aircraft

• Novel on-board electrical loads

including power electronic

converters, machine drive

• Electrical Power System (EPS)

stabilities, system behaviour etc.

• Novel architectures

• Optimization problems

Issues

Background

Fast and accurate models

for aircraft EPS studies

The Science powering Clean Sky 6/3/2016

Multi-layer modelling concept

• Component level

Cover high frequency up to MHz

e.g. Electromagnetic interference (EMI) studies

• Behavioural level

Up to hundreds of KHz

e.g. Switching behaviour of converters

• Functional level

No Switching behaviour in models

System performance: stabilities, transient responses, fault conditions

• Architecture level

Power flow, weight, cost and cabling studies

Architectural

level

Functional level

Behavioural level

Component level

Leve

l of d

eta

ils incre

ase

s

Model c

om

ple

xity

incr

ease

s

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

time(s)

Cure

nt

K=1,Imag partK=1,Re part

DC part

I(t)

T

jk

kdex

Tx n

0

)(1

k

tjk

k

nextx

)(

Fourier Coefficient

Dynamic Phasor Concept

)(X

0

02003

02 03

)(kX

0

To DPs)(1 X )(3 X )(1

X)(3 X

t

Tt

jk

kdex

Ttx n

)(1

)(

k

tjk

k

netxtx

)()(

Dynamic phasors

0

T

t-T

t

DP index A0+ A1sin(ωt+φ1)

+A3 sin(3ωt+φ3)

k=0 A0

k=1 0.5j A1e-jφ1

k=3 0.5j A3e-jφ3

The Science powering Clean Sky 6/3/2016

Dynamic Phasors Modelling Concept

• A better way to represent periodic signals

• Constant complex variables during the steady-state

• Can handle transient and unbalanced conditions

i LR

v+ -

‹i›k LR

+ -

jkωL‹i›k

+ -‹v›k

Time domain

DP domain

0 0.2 0.4 0.6 0.8 10

0.02

0.04

0.06

Time(s)

CP

U ti

me

(s)

0.08 0.081 0.082 0.083 0.084 0.085-20

-10

0

10

20

Cur

rent

s (A

)

DP model

Time-domain model

iL in DPs

Time-domain iL

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Dynamic Phasors Model library

A dynamic phasor library has been developed and tested

• Controlled synchronous generator,

• Generator control units

• Controlled rectifier units,

• Auto-transformer rectifiers

• Electromagnetic actuators

• Cables

• etc

SG1

GCU

SATRU1

PMM

PMM

WIP

S

TSL

SATRU2

SACL

Other AC

load

PMM

Other DC

loadECS1

SG2

GCU

SHVB

HV

AC

1

230V

HV

AC

2

230V

HV

DC

1

540V

Other DC

load

HV

DC

2

570

V

*

Tv

ωe2

*

Tv

EMA1

ωe1

*

1EMA

*

1EMAT

EMA2*

2EMA

*

2EMAT

1, EMAdcv

+

-

SECS1

PMM

ECS2

SECS2

*

1ECST

*

2ECST

SWIP

SESS

iSG1

iSG2

SSG1

SSG2

AC

ES

S

230V

SEMA1

SEMA2

PE

PD

C1

EE

PD

C1

PE

PD

C3

ATRU1

ATRU2

1, EMAdci

1, ECSdci

2, ECSdci

System simulation

• MOET aircraft EPS

architectures

• EMAs, eWIPS, ECS

• A twin-generator

system

• Comparison between

different models: DP,

DQ0 and ABC

ia

Simulation results – balanced conditions

Phase A currents of ATRU1

0 0.2 0.4 0.6 0.8 1 1.2-200

-100

0

100

200

i AT

RU

1(A

)

0.99 1 1.01 1.02 1.03-150

-50

50

150

Time(s)

i AT

RU

1(A

)

ABC DPABC DQ0 |DP|

SATRU1

closes Impact of ECS1 DC demands

ECS1 speed up Loads on ECS1 WIPS onWIPS changes

SGs connect

SGs disconnectedmagnitude of DPs (|<x>|)

0.787 0.7875 0.788 0.7885 0.789 0.7895

-60

-40

-20

0

20

40

60

Computation time

0 0.2 0.4 0.6 0.8 1 1.20

2000

4000

6000

8000

Co

mp

uta

tio

n t

ime(s

)

0 0.2 0.4 0.6 0.8 1 1.20

20

40

60

Time(s)C

om

pu

tati

on

tim

e(s

)

ABC DQ0 DPABC

DPABC DQ0

ABC

Remove SG1

SG1 and SG2 connected

DPABC

DQ0

y=15.44

y=42.97

y=7983

Model ABC DQ0 DP

Time (s) 7983.0 15.44 42.97

Acceleration 1 517 185

The Science powering Clean Sky 6/3/2016

Simulation results – unbalanced conditions

1.19 1.2 1.21 1.22 1.23 1.24 1.25-600

-300

0

300

600

vS

G2a(V

)

1.19 1.2 1.21 1.22 1.23 1.24 1.25-600

-300

0

300

600

vS

G2b

(V)

1.19 1.2 1.21 1.22 1.23 1.24 1.25-600

-300

0

300

600

Time(s)

vS

G2c(V

)

ABC DQ0 DPABC

0 0.2 0.4 0.6 0.8 1 1.2 1.40

1000

2000

3000

4000

5000

6000

7000

Time (s)C

alc

ula

tio

n t

ime

(s)

ABC model

DP model

DQ model

Fault occurs

DP model is the fastest one under unbalanced conditions (150 times faster than DQ0 model)

Aircraft Electrical Power Systems

Innovations Laboratory

115Vac BusHVDC 1

WIPS1

ECS1

GT

PM

PM

PM

BAT HV

PM

PM

PM

PM

PM

HVDC 2

HVDC ESS 2

HVDC ESS 1

Cable 20m

Cable 20m

Cable 10m

Representative Loads

Representative Loads

Representative Loads

“AFT” bus 1

WIPS2

AC grid

AC grid

90kW<1200V, <290A

GSS

90kW<1200V, <290A

GSS

GSS 2x90kW 4-Qactive front-end

converters

DRIVE150kW

35,000rpm4-Q

45kW 32,000rpm PMM Starter/Generator

DRIVETEST RIG

AC grid 50Hz

MX-45

HVAC-1

90kVA, 360-900Hz

AC grid 50Hz

MX-45 90kVA, 360-900Hz

HVAC-2

Cable

HVAC-1-1

Feeders VF

Feeders VF

Cable

HVAC-2-1

Feeders VF

Feeders VF

AC grid 50Hz

AC grid 50Hz

415V/50Hz, 2 x 800A utility grid feeders

Cable ?

“AFT” bus 2 PMM S/G 4kW (like APU driven)

Further plans • Validate models in a

system level

• High-level control ,

monitoring and data

logging

ENGINE EMULATOR

WITH LP and HP

shafts

HP

LP

To feed HVDC 1

To feed HVDC 2

ENGINE EMULATOR (2 shafts: HP and LP) (to be completed 1st Q 2016)

Engine emulator

The Science powering Clean Sky 6/3/2016

Conclusion

• The DP modelling technique has been successfully implemented in

modelling aircraft EPS

• High efficiency and accuracy of the DP models under both balanced

and unbalanced conditions

• 21 journal and conference publications.

• The DP model is included in the SAE Aerospace Information

Report‎AIR6326‎“Aircraft‎Electric‎Power‎System.‎Modelling‎and‎

Simulation.‎Basic‎Definitions”.

The Science powering Clean Sky 6/3/2016

• Sincere thanks to the EU FP7 funding via the Clean Sky JTI –

Systems for green Operations ITD to support this PhD research

• Sincere thanks to Dr. Hitendra Hirani, UNOTT EU Programme

Manager for his support during this Award Applications

End of presentation

Thank you!

Q&A