Laboratoire Plasma et Conversion d’Energie
Mono inverter – Double Permanent Magnet
Synchronous Motor: Structure, Control Strategy
during Normal and Faulty Operation
D. Bidart – L. Chhun - M. Pietrzak-David - M. Fadel - P. Maussion
Abstract
This work presents an original study of a system composed by two PMSM connected in parallel to the same shared inverter. The chosen control strategy is the master
slave configuration: only the master motor is controlled, the slave motor operating in open loop. Two different studies are presented: when both motors have to drive
their own load and when the mechanical load is common and considered as totally rigid. For both studies, theoretical, simulation or experimental results are presented.
Moreover, some results concerning the faulty operation modes are presented. This study has been valued by a patent (US Patent 2007/0273310 A1 Airbus-CNRS).
Mutualisation necessity
PMSM Stability
Vector representation
PMSM interesting for aeronautical
applications (low maintenance,
high efficiency, flexibility … )
Tem, Nm
V
E
q
R 2 + ( L w ) 2 and arg( Z ) = a = a tan(
y
SM1
linear
control
2
Load 1
q1
(is1)1,2
2
2 PMSM plugged in //
èωelec(SM1)=ωelec(SM2)
SM1: closed loop (master)
SM2: open loop (slave)
PMSM stable ó α- p <δ<α
d 1 E2
a
d2
ZI 1
a
I 1 E1
θ2-θ1 calculation
and master motor choice
T1>T2 è θ1< θ2
Experimental test bench
V1=V2
I2
Master motor =
Higher load torque
SM2
controller
i2,1 i2,2
Emulation of
load torque
and resistance
variations
SM2
q2
Position
comparison
+
SM1
i1,1
Tnom=1,4 Nm
Inom=4,6 A;
Ωref=50 rad.s-1
Faulty operation mode
Motor phase disconnection
ke
[Vcos(a - d ) - Ecosa ]
Z
Experimental results:
Current and speed variation
for different load and resistance values
Z.I 2
i1,2
1
Enable
0
q1
Tem, Nm
Wref
1
Tem =
SM1
controller
T1
T2
T ext
time, s
Case 2: Common inelastic mechanical load
Simulation results with common load and
resistance variation
Inverter phase disconnection
ωelec1=ωelec2; Ω1=Ω2
è same variations of δ1 and δ2
è stability of both motors
Conclusions
è System stability: Ω1= Ω2= Ωref
è No additional sensor is required
è Possibility to plugg more than 2 PMSM in //
δ, rad
Case 1: independent loads
Load 2
W1
Lw
)
R
δ=(V;E): load angle
When T2< T1 When T2> T1
δ2<δ1
δ2>δ1
èδ2<α
èPossible
System
instability
stable
δ2>α
p
Independent
or common
d < d Þ d peut être >
mechanical load2
UDC
α
δ1 δ2
E: emf; V: stator voltage
The parallel Master-slave configuration
W2
RI
α-π
Mutualisation:
PMSM plugged in //
to the same inverter
q2
T2
T1
Lw I
Z: stator impedance with:
Z =
SM2
Z.I
I
Reduce the weight and the volume
of the electronics
VS 1,2,3
a
d
y
3 legs
inverter
Open loop stability
è Possibility to use as a redundancy
system.
è Robust with electrical and mechanical
parameter variation and during faulty
operation mode
When R1 ≠ R2 or θ20 ≠ θ10
C1≠C2 è I1≠I2
Master motor =
Higher current value
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