Workshop Lille 2006
International Workshop « Modelling and control of electrical systems »
«Fault-tolerant control of multi-phase machines based on multi machine description» E. Semail, F. Locment, X. Kestelyn
1
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Introduction -
2
Workshop MCES, Lille, November 2006
A G B
51, 43°
F
Introduction
C
E
D
Part 1> 7-phase drive with special design for fault operation Part 2> Opening two phases: effect on the torque of the vector controlled 7-phase machine Part 3> Improved vector control when only 5 phases are supplied M1 VBUS
vM1
iM1
iM1 vM2
iM2
iM2 vM3
iM3
TM1
eM1
M2
SE iBUS
Conclusion
Ω TM3
eM2
M3 m
iM3
eM3
Ω TM2
Ω
T
Ω
SM Ω
TLoad
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Introduction -
3
Workshop MCES, Lille, November 2006
Reliability required for the drives of on-board systems such as automotive, aircraft, marine propulsion, offshore wind-generator Mean Time Between Failure (MTBF) ? Electronic Power Devices are the most critical part of the drive Effect of a failure ? Phases of the machine are opened Critical for wye-coupled 3-phase machines
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Introduction -
4
Workshop MCES, Lille, November 2006
Intrinsic reliability of multi-phase machines Why seven phases ? • using the third harmonic of emf for the torque •smooth torque in fault mode operation (two open phases) • reasonable number of connexions A
30 °
G
jsA2 jsB2
i1
jsB1
B
51, 43°
v1
α
α i5
v2
jsA1
i2
F C
jsΑ3
N
vn (k-2)α
S
vk
jsΒ3
6-phase
E
D
7-phase
ik
5-phase
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Introduction -
5
Workshop MCES, Lille, November 2006
What happens when only 5 phases are supplied ? J Average Torque BUT
L Torque Ripples
Challenges ? 1> Reducing the torque ripples by control 2> Finding a friendly machine for fault operation
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Special design for fault operation -
6
Workshop MCES, Lille, November 2006
A machine
A G B
51, 43°
specifically F
C
designed E
D
for fault operation Special spectrum of electromotive force
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Special design for fault operation -
7
Workshop MCES, Lille, November 2006
Axial flux PM machine, with two rotors
7-leg Voltage Source Inverter
Dspace 100 5 controller board
7-phase axial-flux Supply electron ic charge
Back-ground with DC motor, seven-phase machine and torque transducer (MAGTROL TM211)
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Special design for fault operation -
8
Workshop MCES, Lille, November 2006
N
S
Φ
N
S
Seven phases with toroidal winding
Φ
S
N
(a) NN type
N
S
1 slot/pole/phase
(b) NS type
No filtering effect
Rated Torque with 50°C in winding (Nm)
65
Rated current at 65 Nm (A)
5
4/5 arc pole for the magnet repartition
6 poles
t l u a rf o f g n i t es n r o e i t t a n I oper
5
cancellation of the fifth harmonic
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Special design for fault operation -
9
Workshop MCES, Lille, November 2006
Synoptic of the 7-phase vector control 0
Repartition
Tref
of reference torques
iM1qref 0 iM2qref
vM1αref
PI
+-
R(θ) +-
PI +-
R(9θ) PI
+-
0 iM3qref
+-
R(3θ) +-
PI
iM1q − sin p θ cos p θ
A generalization of 3phase vector control in dq-reference frame
vM2βref
M3α M3β
R-1(θ)
[C 7 ]
vDref
PWM
7-Phase
vEref
VSI
AFPM
vFref vGref
vM3βref iM1α
M1α M1β
M1 i
M3α M3β
M1β
M2α M2β
iM2α R-1(9θ)
iM3d iM3q
vBref
ABCDEFG
iM2d iM2q
vAref
vCref
vM3αref
PI
iM1d
cos p θ R (θ) = sin p θ
M2α M2β
vM1βref vM2αref
PI
M1α M1β
M2 [C ]
−1
iM2β
7
iM3α R-1(3θ)
M3 i M3β
ABCDEFG
θ
iA,iB,iC,iD,iE,iF,iG
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Effect on torque of opening two phases -
10
Workshop MCES, Lille, November 2006
A
Effect of opening
G B
51, 43°
two phases
F C
on a vector controlled 7-phase machine
E
D
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Effect on torque of opening two phases -
11
Workshop MCES, Lille, November 2006
5 4
Phases A and B are opened
3
1 0 -1
TS
-2
-4 -5 0
iA 0.02
0.04
0.06
iB 0.08
iC
iD 0.1
iE
iF
0.12
Time (s)
Measured 7 measured currents currents in normal in fault operation operation without change of control
iG 0.14
RE N
-3
CU R
Currents (A)
2
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Effect on torque of opening two phases -
12
Workshop MCES, Lille, November 2006
Experimental torques in the seven-phase machine
In normal operation
50 40
Torques (Nm)
30
In fault operation
20
S E U Q R O T
10 0
normal mode (NM) without modification (DM1) with modification (DM2)
-10 -20 0
Spectral analysis of torques 25 normal mode (NM) without modification (DM1) with modification (DM2)
)
0.02
0.04
0.06
0.08
0.1
0.12
0.14
20
Interaction between the nonsymmetrical system of currents and the symmetrical system of electromotive forces
Torques (Nm)
Time (s)
15
10
5
0
0
1
2
3
4
Order of harmonics
5
6
« Fault-tolerant control of
- Improved thanks to Multimachine approach Workshop MCES, Lille, November 2006
Improved control thanks to a Multi-machine concept 50 40
Torques (Nm)
30
Torque with improved control
20
S E U Q R O T
10 0
normal mode (NM) without modification (DM1) with modification (DM2)
-10 -20 0
0.02
0.04
Intro part 1 part 2 part 3
a 7-phase machine»
0.06
0.08
Time (s)
0.1
0.12
0.14
13
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Improved thanks to Multimachine approach -
14
Workshop MCES, Lille, November 2006
Tools to get the results ? * Vectorial formalism: important for high number of phases ; * Graphical Energetic Macroscopic Representation; For a wye-coupled 3-phase PM machine
Electrical source
ibus
im
vm
Vbus
im
V oltage S ource I nverter
Tm
Ω
Ω
Tload
MM
em R M 1i M 1 + LM 1
diM 1 = v M 1 − eM 1 dt
Equivalence of a 3-phase machine to a 2-phase machine ( d-q components)
im . em = Tm Ω
Mechanical load
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Improved thanks to Multimachine approach -
15
Workshop MCES, Lille, November 2006
uur uur uuur uuur di RM1iM1 + LM1 M1 = v M1 − eM1 dt vM1 iM1
VBUS
vM2
uuur uur eM1.iM1 = TM1.Ω iM1
iM2
M1 eM1
M2
SE iM2
iBUS
vM3
iM3
eM2
M3 iM3
m
DC bus
Electrical coupling
eM3
Fictitious machine
T = TM1 + TM2 + TM3 TM1 Ω TM2
T
Ω
SM
Ω TM3
Ω
FΩ + J
Ω
Mecanical coupling
Equivalence of a 7-phase machine to a set of 3 2-phase machines
TLoad
dΩ = T − TLoad dt
Load
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Improved thanks to Multimachine approach -
16
Workshop MCES, Lille, November 2006
Basic original idea 6 freedom degrees :
Wye-coupled 7 phase machine VBUS
vM1
iM1
iM1 vM2
iM2
iM2 vM3
iM3
M1 eM1
M2
SE iBUS m
eM3
Ω TM2 Ω TM3
eM2
M3 iM3
TM1
Ω
T
Ω
SM Ω
control of the 3 2-phase machines
TLoad
4 freedom degrees :
In case of 2 open phases
control of only 2 2-phase machines which ones? Impossible to control the currents in one of the three machines No torque ripples in this machine if its EMF = 0
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Improved thanks to Multimachine approach -
17
Workshop MCES, Lille, November 2006
Harmonic characterization Families of odd harmonics
M1
1, 13, 15, 27, …,
M2
5, 9, 19, 23, …,
M3
3, 11, 17, 25, …,
vM1
iM1
iM1 vM2
iM2
iM2 vM3
iM3
M1 eM1
M2
SE iBUS
Ω TM3
eM2
M3 m
iM3
eM3
Ω TM2
Ω
Cancellation of the fifth harmonic
100
TM1
M1 T
SM Ω
TLoad
EXPERIM E N TAL 3D-FEM
80
Ω
Back-emf (%)
VBUS
Fictitious 2-phase machines
M3
60
40
M2 20
0 0 1
3
5
7
9
11
13
15
O rder of harmonics
17
19
21
23
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Improved thanks to Multimachine approach -
18
Workshop MCES, Lille, November 2006
Choice:
Opening of two phases
torque can be imposed by M1 and M3 Physical mandatory currents of M2?
Solution for M2 currents
iM 1α iM 1 β iM 3 α i M 3β
= I M 1 sin (ω t ) = − I M 1 cos (ω t ) =0 =0
0 0 iA I sin ( ) i 0 ωt B M1 i − I M 1 cos (ω t ) iC C i i = = [ C7 ] . i M 2 α D D iE iM 2 β iE i 0 iF F 0 iG − ( iC + iD + i E + iF )
iM 2 α = − I M 1 sin (ω t ) iM 2 β = 0.801938 I M 1 cos (ω t ) − 0.867767 I M 1 sin (ω t )
4+2 current references for the PI controlers
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine» 19
Workshop MCES, Lille, November 2006
Phase A and B opened
55 44 33
Currents (A) Currents (A)
22
And modified control
11 00
-1-1
TS
-2-2
-5-50 0
iiAA 0.02 0.02
0.04 0.04
0.06 0.06
iiBB 0.08 0.08
Time (s) (s) Time
iiCC
iiDD 0.1 0.1
iiEE
iFF
0.12 0.12
Measured Measured currents currents in fault in fault operation operation with without modified changecontrol of control
iG G 0.14 0.14
CU R
-4-4
RE N
-3-3
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Improved thanks to Multimachine approach -
20
Workshop MCES, Lille, November 2006
By the cancellation of the emf fifth harmonic No torque produced by the fictitious M2 machine even if supplied
Without changing modeling of the 7-phase machine No torque ripples by change of M2 reference currents Constant torque references for M1 and M3
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Conclusion -
21
Workshop MCES, Lille, November 2006
Vector control for a 7-phase machine Smooth torque even with non-sinusoidal emf
Vector control with two open phases Average torque but torque ripples
Modified Vector control with two open phases A smooth torque can be obtained in this machine when one or two phases are opened thanks to : •slight modification of the DESIGN of the machine •slight modification of the control
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine» 22
Workshop MCES, Lille, November 2006
50 45 40
Torques (Nm)
35 30 25 20 15 10 5 0 normal operation -5 0
0.02
0.04
0.06
0.08
open-circuited fault (phase A) 0.1
Time (s)
Loss of one phase
0.12
0.14
0.16
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Torque in fault -
23
Workshop MCES, Lille, November 2006
50 45 40
Torques (Nm)
35 30 25 20 15 10 5 0 AB -5 0
0.02
0.04
0.06
AC
0.08
AD 0.1
AE
AF
0.12
Time (s)
Loss of two phases…6 cases
0.14
AG 0.16
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Currents in fictitious machines -
24
Workshop MCES, Lille, November 2006
Without modified control 6
4
Currents (A)
2
0
-2
r u C
-4 iM1αNM -6 0
0.02
iM1β NM 0.04
iM1αDM1 0.06
o s t ren
f 1 fM
iM1β DM1 0.08
Time (s)
o
he t r
iM1αDM2 0.1
0.12
ee r th
ied d s tu
s e s ca
With modified control:
iM1β DM2 0.14
Usual 90° shift between the two currents and same magnitude
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Currents in fictitious machines -
25
Workshop MCES, Lille, November 2006
6
4
0
-2
With modified control
Without modified control 6
-4
4
iM2αNM -6 0
0.02
iM2β NM 0.04
iM2αDM1 0.06
iM2β DM1 0.08
iM2αDM2 0.1
Time (s)
emf of M2 = 0
0.12
iM2β DM2 0.14
2
Currents (A)
Currents (A)
2
ree h t the r fo 2 M f so t n rre u C
es s a dc e i d stu
0
-2
-4
ree h t the r fo 3 f M o ts n e rr Cu iM3αNM
-6 0
0.02
iM3β NM 0.04
iM3αDM1 0.06
iM3β DM1 0.08
Time (s)
s ase c ied d stu
iM3αDM2 0.1
0.12
iM3β DM2 0.14
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Causal inversion -
26
Workshop MCES, Lille, November 2006
vM1 iM1
VBUS
vM2
iM1
iM2
M1 eM1
M2
SE iM2
iBUS
vM3
iM3
eM2
M3 m
iM3
eM3
TM1 Ω TM2 Ω TM3 Ω
T
Ω
SM Ω
TLoad
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Causal inversion -
27
Workshop MCES, Lille, November 2006
vM1 iM1
VBUS
vM2
iM1
iM2
M1 eM1
M2
SE iM2
iBUS
vM3
iM3
eM2
M3 m
iM3
eM3
TM1 Ω TM2 Ω TM3
Ω
T
SM Ω
Ω TM1REF TREF
TM2REF TM3REF KR
TLoad
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Causal inversion -
28
Workshop MCES, Lille, November 2006
vM1 iM1
VBUS
vM2
iM1
iM2
M1 eM1
M2
SE iM2
iBUS
vM3
iM3
eM2
M3 m
iM3
eM3
TM1 Ω TM2 Ω TM3
Ω
T
SM Ω
Ω TM1REF
iM1REF TREF
TM2REF iM2REF TM3REF iM3REF
KR
TLoad
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Causal inversion -
29
Workshop MCES, Lille, November 2006
vM1 iM1
VBUS
vM2
iM1
iM2
M1 eM1
M2
SE iM2
iBUS
vM3
iM3
eM2
M3 m
iM3
eM3
vM1REF
TM1 Ω TM2 Ω TM3
Ω
T
SM Ω
Ω TM1REF
iM1REF vM2REF
TREF
TM2REF iM2REF
vM3REF
TM3REF iM3REF
KR
TLoad
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Causal inversion -
30
Workshop MCES, Lille, November 2006
vM1 iM1
VBUS
vM2
iM1
iM2
M1 eM1
M2
SE iM2
iBUS
vM3
iM3
eM2
M3 m
iM3
eM3
vM1REF
TM1 Ω TM2 Ω TM3
Ω
T
SM Ω
Ω TM1REF
iM1REF vM2REF
TREF
TM2REF iM2REF
vM3REF
TM3REF iM3REF
KR
TLoad
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Examples of multi-phase machines -
31
Workshop MCES, Lille, November 2006
1.3MW By VSI
Induction machine 3*5 phases 20 MW
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Examples of multi-phase machines -
32
Moteur à 2*6 phase PM machine
1,7 - 5 MW 120-150 tr/mn
From Techniques de l’ingénieur (article de Filliau, Bondu, Mazodier)
Workshop MCES, Lille, November 2006
Framatome/Jeumont 2.9 MW
(SIEMENS) PM 2*13 phase machine
« Fault-tolerant control of
Intro part 1 part 2 part 3
a 7-phase machine»
- Examples of axial-flux machines -
33
Workshop MCES, Lille, November 2006
ELEVATOR KONE
Industrial Examples
KAMAN
Axial spatial constraints 100W
4kW
50kW
750kW
ROTATEK
1MW
