Identification of sensitive R-L parameters of a multiphase drive by a vector control A. Bruyere*,**, E. Semail*, F. Locment*, A. Bouscayrol*, J.M. Dubus**, J.C. Mipo** * Arts et Métiers ParisTech, L2EP, Lille, FRANCE ** Valeo Electrical System, Créteil, FRANCE
INTRODUCTION
METHODOLOGY OF IDENTIFICATION iS 1,2,3 d,q-reference
Δ = 9.4A
5
4
5
6
Δ' = 63% 204
T, Ω
imachine
0.018
0.022
ICE
0
iF (A)
2
4
6
8
7-leg VSI
MS
Ω
Control structure
iS3ref iexcref
T1: EMR of the 7-phase synchronous machine
0.026
in the generalized Concordia frame, and S1,2,3 d,q-currents Maximum Control Structure (MCS) Electrical coupling device (energy distribution)
Element with energy accumulation Electromechanical converter with electrical coupling
Control block without controller
Control block with controller
10
Electrical converter (without energy accumulation) Mechanical coupling device (energy distribution) Action and reaction variables. Product of both is the power
Elements of EMR and of control iS1
vS1 iS1
iS2
vS2
eS1
eS2
iS2
iS3
vS3 iS3
eS3
12
iS1ref
iS2 ref ecompensation d
2
iS 1,2,3 d ref
Tau-S1d τ-S1d Tau-S1q τ-S1q
τ (ms)
1
Tau-S2d τ-S2d
B
0,5
Tau-S2q τ-S2q
iS3 ref
0
iF2(A)
4
6
8
10
τ-S3q 12Tau-S3q 14
Time constants (Fig. A) and resistances (Fig. b) as a function of the excitation current (A); N=0rpm
CONCLUSION
In order to establish the control of a 7-phase starter-alternator drive and to build virtual models, 7-phase starter-alternator experimental set-up a good knowledge of its electrical parameters and time constants is needed. Due to the low voltage ELECTRIC MATHEMATICAL and the high number of phases of the studied DESCRIPTION IN A CONTROL FRAME drive, determination of the time constants, using classical inductive measurements in the stator ⎧v0 = L0 d (i0 ) / dt + RS i0 + e0 :ignored (i0 always null) frame, implies uncertainties. An experimental ⎪ methodology has been developed in order to ⎪v S1−d = LS1−d d (iS1−d ) / dt + RS iS1−d + eS1−d ⎪v measure these electrical parameters. The time S 1− q = LS 1−q d (i S 1− q ) / dt + RS iS 1− q + eS 1− q ⎪⎪ constants measurement is direct and the v L d ( i ) / dt R i e = + + ⎨ S 2−d S 2−d S 2− d S S 2− d S 2− d methodology allows to take into account all ⎪v = LS 2−q d (iS 2−q ) / dt + RS iS 2−q + eS 2−q parasitic resistances (of the MOSFET transistors ⎪ S 2−q ⎪v S 3−d = LS 3−d d (iS 3−d ) / dt + RS iS 3−d + eS 3−d and at electrical connections), which are not ⎪ negligible in this low voltage automotive ⎪⎩v S 3−q = LS 3−q d (iS 3−q ) / dt + RS iS 3−q + eS 3−q application: it is really the identification of the In the generalized Concordia frame, under drive, and not only of the electrical machine, that assumptions, 6 independent dq-axes equations has been achieved.
Cd(s)
+-
ed
+ +
+
ecompensation q
iS 1,2,3 reference iS 1,2,3 q ref +
Tau-S3d τ-S3d
0
7-phase Starter-Alternator
TLoad
2,5
1,5
dSpace DS1006
Ω
iS2ref
vexcref
3
Brushless machine (ICE behavior simulation)
T
Ω
iS1ref
vS2ref vS3ref
R-S1d-average-meas R-S1q-average-meas R-S2d-average-meas R-S2q-average-meas R-S3d-average-meas R-S3q-average-meas
5
TS2
Ω TS3
S3 eS3
iS3
25
A
S2
iS3
vS1ref vVSI ref
Ω
eS2
vS3
Source of energy
0
7-phase starter-alternator system description
iS2 iS2
7-phase drive modeling in Concordia subspaces
TS1
S1 eS1
vS2
mVSI
30
10
iexc vexc
vVSI
iVSI
With Kp=0.02: Rs = 22.6mΩ τ -S1-q = 2.15ms
15
SM 7
VDC
iDC
20
6
VDC
Rbatt
v1 7
i1
iS1 3
Ebatt V-
θ 1
VDC
0.028
202
RS (mΩ)
iDC V+
ES
iq-measurement
0.02
iS1 iS1
τ -S1-q-closed-loop = 1.14ms
200
Excitation circuit modeling
eSR
vS1
GLOBAL RESULTS Belt
iF
iexc
198
(s)
iexc eSR-S1
iexc
mchop
196
iq-reference
2
4
vexc
VDC ichop
Example: S1q axis, step-ref=20A, N = 0rpm, iF = 3A
iq-measurement
-250
206 0.014
12V battery
1 2
1st order system with e as a perturbation
-150
-450 0.012 Time
3
1 + τ S1,2,3 d,q
id-measurement and id-reference
-50
7-phase synchronous claw pole machine
12V
K S1,2,3 d,q iS 1,2,3 d,q
-
S1-subspace: d- and q-axes currents = f(t)
50
-350
7-leg VSI
+
Control of one single axis of a dq subspace (T2-T3)
7-PHASE STARTER-ALTERNATOR DESCRIPTION
+ +
C(s)
+-
Lille
TOOLS: Building the control structure of the 7-phase machine currents in the generalized Concordia frame, using Energetic Macroscopic Representation (EMR)
e
Controller
Magnitude (A)
This study focuses on a specific 7-phase drive: a belt driven starter-alternator for powerful cars with Hybrid Electrical Vehicles (HEV) functions. The resistive and inductive parameters are necessary to obtain the six characteristic time constants of the control modeling. Classical direct measurements lead to imprecise results because of very low values for the windings electric resistance (a few mΩ) and inductance (a few µH). Here is described an original methodology of identification, based on a stator current vector control, in the generalized Concordia multi-reference frame. This methodology allows to directly get the time constants needed for controlling the drive.
ecompensation
CNRT Futurelec
-
Cq(s)
vS 1,2,3
+ +
K S1,2,3 d
iS 1,2,3 d
1 + τ S1,2,3 d
iS 1,2,3
eq
+
d- and q-currents controllers Cd,q(s), with compensation of the perturbation e
-
-
K S1,2,3 q 1 + τ S1,2,3 q
iS 1,2,3 q
Two 1st order system (d- and q-axes) with e as a perturbation
T2: equivalence between EMR and block diagrams for controlling the dq-currents in S1, S2 and S3 0
iS1q-reference 0
0
0
0
++-
K p−S1d +
Ki −S1d s
K p−S1q
+-
K p−S 2d +
+-
K p−S 2q +
+-
K p−S 3d +
+-
K p−S3q +
KS1d 1+τ S1d s
iS1d
KS1q
iS1q
1+τ S1q s KS 2d 1+τ S 2d s
iS2d
Ki−S 2q
KS 2q
iS2q
s
1+τ S 2q s
Ki −S3d s
KS3d 1+τ S3d s
iS3d
Ki−S3q
KS 3q
iS3q
s
1+τ S3q s
Ki−S 2d s
T3: identification of the S1q-current-axis parameters: global control structure of the dq-currents when the perturbation e is perfectly compensated.
