Numerical and Hardware-in-the-Loop Simulation
of Pantograph-Catenary Interaction
Stefano Bruni, Giuseppe Bucca, Andra Collina, Alan Facchinetti
Pantograph Catenary Interaction Framework for Intelligent Control
Amiens, France, December 8th, 2011
Introduction
2
 The assessment of the performance of a given pantographcatenary system is usually based on line measurements
 Experimental test runs are extremely time-consuming and
expensive
 The availability of simulation tools for pantograph-catenary
dynamic interaction is essential or at least can reduce the
number of required line tests for:
• design of new systems
• optimisation of existing systems
• interoperability analyses
• virtual homologation (PantoTRAIN)
• …
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
Contents of the presentation
3
1. Mathematical model and numerical simulation of
pantograph-catenary interaction
2. Hybrid simulation of pantograph-catenary interaction
3. Comparison of the simulation tools with line measurements
4. Effect of contact strip deformability
5. Effect of contact dynamics on contact wire wear
6. Concluding remarks
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
Mathematical model of pantograph-catenary
interaction
4
 The development of a mathematical model for pantographcatenary dynamic interaction started at Politecnico di Milano
several years ago
 Cooperation with Italferr and former FS (Italian State Railways),
now RFI (Rete Ferroviaria Italiana)
 Simulation tool mainly intended for the assessment of current
collection quality, continuously updated

•
•
•
Software was successfully applied:
to the design of the new Italian 25 kV a.c. high speed line
for the upgrading of the existing Italian 3 kV d.c. line
for the design of several applications world-wide, in support of
the main overhead line suppliers.
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
Mathematical model: the catenary model
5
Traditional wire droppers
Elastic ring dropper
 Finite element schematisation of the
contact wire and of the messenger wire
 Droppers included as non linear element
(non-linear characteristic obtained from
laboratory tests)
[Mc ]x c + [R c ]x c + [K c ]x c = Fcc (x c ) + Fcp (x c ,x c ,x p ,x p ,t)
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
Mathematical model: the pantograph model
6
FRF - Head
Mod. [m s -2/N]
0.4
exp 1mm
exp 5mm
exp 20mm
model
0.3
0.2
0.1
0
0
2
4
6
8
10
f [Hz]
12
14
16
18
20
0
2
4
6
8
10
f [Hz]
12
14
16
18
20
Phase [deg]
0
-50
-100
-150
-200
 Pantograph represented as a non-linear lumped parameter system
(identification from experimental FRF)
 Bending deformability of the collectors introduced by modal superposition
approach (impact tests on the single collector)
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
Mathematical model: the interaction model
wj
Fc
Catenary
zcc = fwjTmotion
(xcj )x j + zirr (t)
7
Contact law
(penalty method)
Fc
zcc
w j-1
 cj
Fc
a
zcp
Collector motion
zcp = FT (xci )qi
Fc
ìï[Mc ]x c + [R c ]x c + [K c ]x c = Fcc (x c ) + Fcp (x c ,x c ,x p ,x p ,t)
í
ïî[M p ]x p + [R p ]x p + [K p ]x p = Fpc (x p ,x p ,x c ,x c ,t)
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
Hybrid (HIL) simulation of pantograph-catenary
interaction
xC
8
FC
ksosp
rsosp
ksosp
rsosp
ρp, Ap, EJp, Lp, Sp
Fpend,i
y
m
x
mc
m
mc ρFc, AFc, EJFc, LFc, SFc
Fpant
v
Real-time catenary model
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
Hybrid simulation: the HIL test-rig
9
Lateral actuation (stagger)
Electromechanical
up to ±400mm @ 360 km/h
Vertical actuation
2 independent
hydraulic actuators
up to 25 Hz
Load cells
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
Hybrid simulation: the catenary model
10
f dj
compression
 3-5 spans (periodic structure)
 CW and MW represented through modal
superposition approach (tensioned beams)
 Effect of droppers’ slackening
 “Shift forward” procedure
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
traction
! lj
Comparison of numerical simulation with line
measurements
11
ATR95 pantograph - C270 catenary (25 kV a.c.)
V = 300 km/h
Time histor of the contact force
(approximately 3 spans)
1/3 octave band frequency
spectra of the contact force
CW irregularity was considered in the numerical simulation
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
Comparison of hybrid simulation with line
measurements
12
ATR95 pantograph - C270 catenary (25 kV a.c.)
V = 300 km/h
Time history of the contact force
(approximately 3 spans)
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
1/3 octave band frequency
spectra of the contact force
Comparison with line measurements
13
ATR95 pantograph - C270 catenary (25 kV a.c.)
V = 300 km/h
Line tests - average
σF
[N]
47.1
σF 0-2 Hz
[N]
17.1
σF 7-18 Hz
[N]
40.2
Line tests – max.
48.9
20.9
41.5
Line tests – min.
46.1
15.1
39.3
Hybrid simulation
43.7
17.6
37.8
% deviation
7.3%
1.6%
6.1%
Numerical simulation
37.0
16.8
29.4
21.5%
2.1%
27.0%
% deviation
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
Effect of contact strip deformability (numerical
simulation)
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
14
Exp. freq. [Hz]
FE freq. [Hz]
60.1 Hz
60 Hz
76.9 Hz
76.2 Hz
136 Hz
136 Hz
Effect of contact strip deformability (numerical
simulation)
15
V=270 km/h
without
deformability
V=330 km/h
V=270 km/h
with
deformability
V=330 km/h
Spectra of the vertical
accelerations of the front collector
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
Contact losses percentage
Effect of contact dynamics on contact wire wear
(numerical simulation)
16
Procedure for the estimation of wear evolution
V
i
Numerical simulation
of the pantographcatenary interaction
Fc
Wear model
A=f(Fc,i,V)
N pass.
Initial irregularity
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
A
Evolution of CW
irregularity
(single passage)
The wear model
17
Wear model
A=f(Fc,i,V)
Heuristic model of contact wire wear, tuned on the basis of
experimental data
Electrical contribution
Mechanical contribution



i   Fc  V Fc
R(Fc )i 2
A  k1  1    
 k2
HV
 i 0   F0  V0 H
A = worn area, Fc = contact force, i = current intensity, V = sliding speed,
H = hardness of CW material, F0, i0, V0 = reference value,
R(Fc) = electrical contact resistance
α, β, k1 and k2 identified from experimental data
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
Test rig for the study of wear behaviour of contact
strip and contact wire
18
The test-rig enables the testing of full scale collectors at speeds
up to 200 km/h, imposing electrical current intensity up to 1200
A dc, 500 A ac 162/3 Hz and 350 A ac 50 Hz.
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
Test rig for the study of wear behaviour of contact
strip and contact wire
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
19
Test rig for the study of wear behaviour of contact
strip and contact wire
Rotating fibre-glass
disk (R = 2 m)
Contact wire
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
19
Test rig for the study of wear behaviour of contact
strip and contact wire
Collector
Hydraulic
actuator
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
19
Test rig for the study of wear behaviour of contact
strip and contact wire
Ventilation apparatus
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
19
Results from wear tests: contact resistance
20
Contact resistance vs contact force
kR
R( Fc ) 
Fc
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens

k R  4.97 10 2 N 1 / 2

Results from wear tests: Contact wire Specific
Wear Rate
CW SWR vs
contact force
Vlm
SWR =
s × FC
21
CW SWR vs current
Vlm = volume of lost material [mm3]
s = travelled distance [km]
FC= Contact force [N]
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
Results from wear tests: Contact wire Specific
Wear Rate
æ
iö
A = k1 ç 1+ ÷
è i ø
0
-a
b
æ Fc ö V Fc
R(Fc )i 2
çè F ÷ø V H + k 2 H × V
0
0
k1, k2,  and β
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
22
Evolution of the worn area of the contact wire
23
Comparison between numerical results for two different values of
the mechanical tension of the contact wire, i.e. 17 kN and 20 kN
mid
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
Concluding remarks
24
 The numerical simulation and hybrid co-simulation represent
useful means to investigate the pantograph-catenary dynamic
interaction before line-testing
 The degree of accuracy that can be obtained with these two
techniques is more than satisfactory
 Mathematical models can also give some insight into some of the
phenomena involved in pantograph-catenary interaction, e.g. the
effects of collector deformability and wear process concerning
contact wire and collector strip
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens
28
A. Facchinetti PACIFIC’2011, December 18th, 2011, Amiens