« fault tolerant control for 7 phase bldc machines
TRANSCRIPT
EMR’18
Hanoi (Vietnam)
June 2018
« FAULT TOLERANT CONTROL FOR 7 PHASE BLDC
MACHINES »
Duc Tan VU, Dr. Ngac Ky NGUYEN, Prof. Eric SEMAIL
L2EP Laboratory, Arts et Métiers ParisTech, Lille, France
Joint Summer School EMR’18
“Energetic Macroscopic Representation”
2
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
- Introduction -
1. Introduction
2. Role of EMR in the system design
3. Role of EMR in the system control
4. Biographies and references
A
B
C
DE
F
G
51,43°
7 phase BLDC machine developed by L2EP
EMR’18
Hanoi (Vietnam)
June 2018
« INTRODUCTION »
4
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
• Electrical machines are more and more interesting in many means of
transportation and also in electricity generation.
• Reliability required for the drives of on-board systems such as:
automotive, aircraft, marine propulsion, offshore wind-generator
- Introduction -
5
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
1. Decrease the phase current comparing to a three phase machine for a given low DC bus (48V) reduce the power-per-phase converter and machine rating.
2. Increase fault-tolerance capabilities (open-circuit and short-circuit).
3. Reduce torque ripples at low harmonics.
4. Different possibilities of stator winding configuration high speed range without flux weakening.
Multiphase machines
- Introduction -
Why ?
6
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
- Introduction -
1 1
dn nd d dk
k s k k k
k k
div v R i e
dt= =
= = + +
rrr r r
According to vectorial formalism, the voltage and electromagnetic torque
are expressed as:
Real n-phase machine TORQUE
TORQUE
L L
Fictitious Machines (diphase + homopolar)
Fictitious machines Shape of the back-EMF
(sinusoidal/trapezoidal or others)
T
1
dT 2
dT d
nT
7
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
- Introduction -
Real 7-phase PMSMTORQUE
Fictitious Machines (3 diphase + 1 homopolar)
Main
Machine
Second
Machine
h = 1, 13, 15, 27
h=7k ± 1
h = 5, 9, 19, 23,
h=7k ± 2
h = 7, 14, 21, …
h=7k
Notes
-Wye connection: current of homopolar machine.
i0=0 T0=0
-Symmetrical machines: there are no even harmonics of the back-EMF.
MM SM HM
Simplification
Third
Machine
TM
h = 3, 11, 17, 25, …
h=7k ± 3
Homo.
Machine
EMR’18
Hanoi (Vietnam)
June 2018
« ROLE OF EMR IN THE SYSTEM
DESIGN »
9
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
Equivalence of a 7-phase machine to
a set of 3 fictitious 2-phase machines
- Role of EMR in the system design -
TM3
TM1
SMT
vM1
eM1
M1
M2
M3
iM1
iM2
iM3
vM2
vM3
eM3
eM2
TM2
iM1
iM2
iM3
SE
VBUS
iBUS
TLoad
m
TM3
TM1
SMSMT
vM1vM1
eM1eM1
M1M1
M2M2
M3M3
iM1iM1
iM2iM2
iM3iM3
vM2vM2
vM3vM3
eM3eM3
eM2eM2
TM2
iM1iM1
iM2iM2
iM3iM3
SE
VBUS
iBUS
TLoad
mm
DC busElectrical
coupling
Fictitious
machineLoad
Mecanical
coupling
+ = −
uuruur uuur uuur
M1M1 M1 M1 M1 M1
diR i L v e
dtM1 M1 M1e .i T .=
uuur uurM1 M2 M3T T T T= + +
+ = − Load
dF J T T
dt
SE SM
DC busElectrical
coupling Fictitious machinesMechanical
coupling Load
10
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
Basic original idea
Wye-coupled 7 phase machine
6 degrees of freedom:
control of the 3 2-phase
fictitious machines
In case of 1 open phase
5 degrees of freedom:
control of only 2 2-phase
fictitious machines
- Role of EMR in the system design -
In case of 2 open phases
4 degrees of freedom:
control of only 2 2-phase fictitious
machines
TM3
TM1
SMT
vM1
eM1
M1
M2
M3
iM1
iM2
iM3
vM2
vM3
eM3
eM2
TM2
iM1
iM2
iM3
SE
VBUS
iBUS
TLoad
m
TM3
TM1
SMSMT
vM1vM1
eM1eM1
M1M1
M2M2
M3M3
iM1iM1
iM2iM2
iM3iM3
vM2vM2
vM3vM3
eM3eM3
eM2eM2
TM2
iM1iM1
iM2iM2
iM3iM3
SE
VBUS
iBUS
TLoad
mm
11
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
0 1 3 5 7 9 11 13 15 17 19 21 230
20
40
60
80
100
Order of harmonics
Bac
k-e
mf
(%
)EXPERIMENTAL
3D-FEM
M2
M1
M3
0 1 3 5 7 9 11 13 15 17 19 21 230
20
40
60
80
100
Order of harmonics
Bac
k-e
mf
(%
)EXPERIMENTAL
3D-FEM
M2
M1
M3
First IDEA after EMR
representation
FOR the DESIGN:
Cancellation of
the fifth harmonic
- Role of EMR in the system design -
TM3
TM1
SMT
vM1
eM1
M1
M2
M3
iM1
iM2
iM3
vM2
vM3
eM3
eM2
TM2
iM1
iM2
iM3
SE
VBUS
iBUS
TLoad
m
TM3
TM1
SMSMT
vM1vM1
eM1eM1
M1M1
M2M2
M3M3
iM1iM1
iM2iM2
iM3iM3
vM2vM2
vM3vM3
eM3eM3
eM2eM2
TM2
iM1iM1
iM2iM2
iM3iM3
SE
VBUS
iBUS
TLoad
mm
12
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
By the cancellation of the fifth harmonic of EMF
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
- Role of EMR in the system design -
1st CONCLUSION: the EMR is a tool for the drive design
EMR’18
Hanoi (Vietnam)
June 2018
«ROLE OF EMR IN THE SYSTEM CONTROL»
14
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
- Role of EMR in the system control-
• Especially, EMR is interesting for the definition of control strategies:
→Control in normal mode when the number of freedom degrees are
higher than the minimum (two currents are only necessary for a constant
torque):
– Minimization of Copper Losses
– Minimization of Peak Current
– Minimization of Peak Voltage
– Minimization of Losses under voltage constraints
– …
→Control in faulty modes also with optimization
EMR is also a tool for the design of the control!
We will focus on fault mode control
15
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
- Role of EMR in the system control -
Structure of the control thanks to EMR approach
Apply causal inversions to find the controller (IBC) of each element of the
structure
TM3
TM1
SMT
vM1
eM1
M1
M2
M3
iM1
iM2
iM3
vM2
vM3
eM3
eM2
TM2
iM1
iM2
iM3
SE
VBUS
iBUS
TLoad
m
TM3
TM1
SMSMT
vM1vM1
eM1eM1
M1M1
M2M2
M3M3
iM1iM1
iM2iM2
iM3iM3
vM2vM2
vM3vM3
eM3eM3
eM2eM2
TM2
iM1iM1
iM2iM2
iM3iM3
SE
VBUS
iBUS
TLoad
mm
SE SM
16
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
- Role of EMR in the system design and control -
TREFTM2REF
TM3REF
TM1REF
KR
TREFTM2REF
TM3REF
TM1REF
KR
TM3
TM1
SMT
vM1
eM1
M1
M2
M3
iM1
iM2
iM3
vM2
vM3
eM3
eM2
TM2
iM1
iM2
iM3
SE
VBUS
iBUS
TLoad
m
TM3
TM1
SMSMT
vM1vM1
eM1eM1
M1M1
M2M2
M3M3
iM1iM1
iM2iM2
iM3iM3
vM2vM2
vM3vM3
eM3eM3
eM2eM2
TM2
iM1iM1
iM2iM2
iM3iM3
SE
VBUS
iBUS
TLoad
mm
TREF
ΩREF
KR is distribution coefficient to determine which machine is used to generate torque
strategy
SE SM
17
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
- Role of EMR in the system control -
iM1REF
iM2REF
iM3REF
iM1REFiM1REF
iM2REFiM2REF
iM3REFiM3REF
TREFTM2REF
TM3REF
TM1REF
KR
TREFTM2REF
TM3REF
TM1REF
KR
TM3
TM1
SMT
vM1
eM1
M1
M2
M3
iM1
iM2
iM3
vM2
vM3
eM3
eM2
TM2
iM1
iM2
iM3
SE
VBUS
iBUS
TLoad
m
TM3
TM1
SMSMT
vM1vM1
eM1eM1
M1M1
M2M2
M3M3
iM1iM1
iM2iM2
iM3iM3
vM2vM2
vM3vM3
eM3eM3
eM2eM2
TM2
iM1iM1
iM2iM2
iM3iM3
SE
VBUS
iBUS
TLoad
mm
TREF
ΩREF
eM1lleM1ll
2
TM1REF.iM1REF =
strategy
SE SM
18
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
- Role of EMR in the system control -
iM2dREF
vM2REF
vM2REFR(9)R(9)
R-1(9)R-1(9)
PIPI-+-+
-+-+iM2qREF
PIPI
iM2
iM2
iM2d
iM2q
++
++
++
++
eM2d eM2q
( )cosp sin p
Rsin p cosp
− =
strategy
iM1REF
iM2REF
iM3REF
iM1REFiM1REF
iM2REFiM2REF
iM3REFiM3REF
vM1REF
vM2REF
vM3REF
vM1REFvM1REF
vM2REFvM2REF
vM3REFvM3REF
TREFTM2REF
TM3REF
TM1REF
KR
TREFTM2REF
TM3REF
TM1REF
KR
TM3
TM1
SMT
vM1
eM1
M1
M2
M3
iM1
iM2
iM3
vM2
vM3
eM3
eM2
TM2
iM1
iM2
iM3
SE
VBUS
iBUS
TLoad
m
TM3
TM1
SMSMT
vM1vM1
eM1eM1
M1M1
M2M2
M3M3
iM1iM1
iM2iM2
iM3iM3
vM2vM2
vM3vM3
eM3eM3
eM2eM2
TM2
iM1iM1
iM2iM2
iM3iM3
SE
VBUS
iBUS
TLoad
mm
TREF
ΩREF
SE SM
iM1dREF
iM1qREF
eM1deM1q
iM1α
iM1β
iM1d
iM1q
ϴ
vM1αREF
vM1βREF
19
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
- Role of EMR in the system control -
iM1REF
iM2REF
iM3REF
iM1REFiM1REF
iM2REFiM2REF
iM3REFiM3REF
vM1REF
vM2REF
vM3REF
vM1REFvM1REF
vM2REFvM2REF
vM3REFvM3REF
TREFTM2REF
TM3REF
TM1REF
KR
TREFTM2REF
TM3REF
TM1REF
KR
TM3
TM1
SMT
vM1
eM1
M1
M2
M3
iM1
iM2
iM3
vM2
vM3
eM3
eM2
TM2
iM1
iM2
iM3
SE
VBUS
iBUS
TLoad
m
TM3
TM1
SMSMT
vM1vM1
eM1eM1
M1M1
M2M2
M3M3
iM1iM1
iM2iM2
iM3iM3
vM2vM2
vM3vM3
eM3eM3
eM2eM2
TM2
iM1iM1
iM2iM2
iM3iM3
SE
VBUS
iBUS
TLoad
mm
TREF
ΩREF
2nd CONCLUSION: the EMR is a tool for a control design
strategy
SE SM
20
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
Experimental torques of the seven-phase machine
0 1 2 3 4 5 60
5
10
15
20
25
Order of harmonics
Torq
ues
(N
m)
normal mode (NM)
without modification (DM1)
with modification (DM2)
Spectral analysis of torques
In normal operation
In fault operation
Interaction between the non-symmetrical system
of currents and the symmetrical EMFs
- Role of EMR in the system control -
1 opened phase fault
2
opened
phase
fault
To
rqu
es (
Nm
)
Time (s)
21
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
A
B
C
DE
F
G
51,43°
- Role of EMR in the system control -
A
B
C
DE
F
G
51,43°
0 0.02 0.04 0.06 0.08 0.1 0.12 0.14-5
-4
-3
-2
-1
0
1
2
3
4
5
Time (s)
Cu
rren
ts (
A)
iA
iB
iC
iD
iE
iF
iG
Curr
ents
(A
)
Time (s)
Strategy without
constrains on voltage
and current
22
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
- Role of EMR in the system control -
Constraints on voltage and current?
Modified strategy
iM1REF
iM2REF
iM3REF
iM1REFiM1REF
iM2REFiM2REF
iM3REFiM3REF
vM1REF
vM2REF
vM3REF
vM1REFvM1REF
vM2REFvM2REF
vM3REFvM3REF
TREFTM2REF
TM3REF
TM1REF
KR
TREFTM2REF
TM3REF
TM1REF
KR
TM3
TM1
SMT
vM1
eM1
M1
M2
M3
iM1
iM2
iM3
vM2
vM3
eM3
eM2
TM2
iM1
iM2
iM3
SE
VBUS
iBUS
TLoad
m
TM3
TM1
SMSMT
vM1vM1
eM1eM1
M1M1
M2M2
M3M3
iM1iM1
iM2iM2
iM3iM3
vM2vM2
vM3vM3
eM3eM3
eM2eM2
TM2
iM1iM1
iM2iM2
iM3iM3
SE
VBUS
iBUS
TLoad
mm
TREF
Fault information
Modified Strategy
with constraints on
voltage and current
SE SM
2nd CONCLUSION: the EMR is a tool for a control design
23
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
- Role of EMR in the system control -
7-phase
machine
7-phase
VSI+PWM
Optimization
Machine
parameters
Vmax ,Imax
Look-up table
Ω
Fault
information
VDC
T,H1,H2,H3,H4
and PI controller
θ
iabcdefg
d/dt
ic ie if ig Imaxid
Modified strategy with constrains
on voltage and current
D. T. Vu, N. K. Nguyen, E. Semail, and T. J. d. S. Moraes, "Torque optimization of seven-phase BLDC machines in normal and
degraded modes with constraints on current and voltage," in The 9th International Conference on Power Electronics, Machines and
Drives, Liverpool, UK, 4/2018.
24
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
- Conclusions -
• EMR provides tools for the machine design and also control design.
• It enables to have an overview as well as detailed elements of the
system.
Conclusions
EMR’18
Hanoi (Vietnam)
June 2018
« BIOGRAPHIES AND REFERENCES »
26
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
- Authors -
Dr. Ngac Ky NGUYEN
Arts et Métiers ParisTech, L2EP, France
PhD in Electrical Engineering at University of Mulhouse (2010)
Associate Professor since 2012
Research topics: Multiphase machines control, fault tolerance systems, EMR
Prof. Eric SEMAIL
Arts et Métiers ParisTech, L2EP, France
PhD in Electrical Engineering at University of Lille 1 – Science and Technology (2000)
Full Professor since 2010
Research topics: Multiphase machines design and control, multi-converter modelling
Duc Tan VU
Arts et Métiers ParisTech, L2EP, France
PhD student in Electrical Engineering
Research topics: Multiphase machines control, fault tolerance system, modelling
and control of multi-physique systems
27
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
-Conclusions and references-
[1] F. Locment, E. Semail, and X. Kestelyn, "Optimum use of DC bus by fitting the back-
electromotive force of a 7-phase permanent magnet synchronous machine," in 2005 European
Conference on Power Electronics and Applications, 2005, pp. 1-9
[2] F. Locment, E. Semail, and F. Piriou, "Design and study of a multiphase axial-flux machine," IEEE
Transactions on Magnetics, vol. 42, pp. 1427-1430, 2006.
[3] F. Jen-Ren and T. A. Lipo, "Disturbance-free operation of a multiphase current-regulated motor
drive with an opened phase," IEEE Transactions on Industry Applications, vol. 30, pp. 1267-1274,
1994.
[4] O. Fall, N. K. Nguyen, J. F. Charpentier, P. Letellier, E. Semail, and X. Kestelyn, "Variable speed
control of a 5-phase permanent magnet synchronous generator including voltage and current limits in
healthy and open-circuited modes," Electric Power Systems Research, vol. 140, pp. 507-516, 11/2016.
[5] D. T. Vu, N. K. Nguyen, E. Semail, and T. J. d. S. Moraes, "Torque optimization of seven-phase
BLDC machines in normal and degraded modes with constraints on current and voltage," in The 9th
International Conference on Power Electronics, Machines and Drives, Liverpool, UK, 4/2018.
[6] D. T. Vu, N. K. Nguyen, E. Semail, “Sensitivity of Torque Control for Seven-phase BLDC
Machine with One Opened Phase under Constraints on Voltage and Current”, the 24th edition of the
International Symposium on Power Electronics, Electrical Drives, Automation and Motion, Amalfi,
Italy, 6/2018.
References
28
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
THANK YOU FOR YOUR ATTENTION!
29
« Fault tolerant control for 7 phase BLDC machines»
EMR’18, Hanoi, June 2018
• Smooth torque in fault mode operation (two open phases)
Why seven phases ?
A
B
C
DE
F
G
51,43°
• Using the third harmonic of back-EMF for the torque
jsB1jsB2
jsB3
jsA1
jsA2
jsA3
30
°
6-phase
i1
v1
i5
i2
ik
v2
vn
vk
N
S(k-2)
5-phase 7-phase
• Reasonable number of connections
- Introduction -