technische universitätdortmund
Faculty of Electrical Engineering and
Information Technology
On-Board Systems Lab
Comparative Study of Transfer Impedance (ZT) Measurement
Methods and Simulationmodels to Analyze Shielding
Behaviour of High Voltage Cables in Electric VehiclesM.Sc. Abid Mushtaq, Dipl.-Wirt.-Ing. Katharina Hermes,
Prof. Dr. -Ing. Stephan Frei.
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Content
Introduction
Measurement methods
Simulation methods
Conclusions
2
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Content
Introduction
Motivation
Basic Terminology
Measurement methods
Simulation methods
Conclusions
3
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Motivation
Problem Overview
In Electrical Vehicles (EV) and Hybrid-Electrical Vehicles (HEV)
Power drive systems, inverters convert and provide PWM signals at high voltage
(Vpeak-to-peak ≥ 300V) to drive the E-motors via HV-cables (shielded power cables)
EMI noise signals from these HV-cables may cause malfunction of LV
electronics devices, MCUs, vehicular communication networks (LIN, CAN,
Flexrays, MOST, etc), AM Radio, etc
4
HV Cable-Connectors
Inverter
HV Cables
EMI Noise
Low Voltage Systems
HV Connectors
3P
MotorBattery
pack
Low Voltage Systems
• Optimum shielding of the HV-cables and HV-connectors
Dummy inverter with HV
Cable-Connectors
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Motivation
Steps:
How to evaluate shielding performance of HV-shielded cables?
Shielding Effectiveness vs. Transfer Impedance
Shielding Effectiveness (SE)
Is a measure for the not just shielded cable, but also depends on external parameters
For the same shield, we can get different SE by varying the external parameters
Good for overall integrated system shielding analysis
Transfer Impedance (ZT)
Is an intrinsic property of the shield, and doesn’t depend on external parameters
For the same shield, ZT is independent of external parameters like termination load,
external layouts, etc.
Good for component level shielding analysis
Main focus of this talk is on ZT:
Predicting Transfer Impedance using simulation and measurement methods
5
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Motivation
Basic Terminology
Transfer Impedance (ZT)
It is defined as:
6
SHIELDT
SHIELD SHIELD
dVZ
I l
Simulation methods
Based on braid parameters,
dimensions, ZT can be predicted
Based on circuit models
Measurement method
Based on above formula,
various test setup have been proposed (Triaxial Method and
Line Injection Method)
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Content
Introduction
Measurement methods
Existing methods
Ground Plate Method (GPM)
Capacitive Voltage Probe (CVP) Method
Simulation methods
Conclusions
7
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Measurement methods
Existing methods
ZT measurement methods
Triaxial Method (IEC 62153-4-3)
Complex structure for variable sizes and connectors
Variable size of tubes require for different sizes and shapes, specially for connectors
Line Injection Method (LIM) (IEC 62153-4-6)
For non-symmetrical cables and connector assemblies, different positioning of the
injection wires can cause inaccuracy in measured results
8
Triaxial tube
Triaxial cell
LIM Cable test
LIM Cable-Connector test
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Measurement methods
Use of alternative methods to measure ZT
For shielding analysis of HV-cable-connector systems, it should be
Flexible to measure ZT of non-symmetrical samples
and large connectors
With maximum accuracy and better repeatability/reproducibility
To overcome these issues in HV-cable-connector analysis, following
methods are used:
Ground Plate Method (GPM)
Overcomes the limitation of the existing methods
Flexible to measure ZT of non-symmetrical samples and large connectors
Ability to correlate with Antenna measurements with least variation in test setup
Capacitive Voltage Probe (CVP) measurement
Direct measurement of Voltage over the shield
Transfer Impedance can be approximated using both voltage and input current
Ability to correlate with Antenna measurements with least variation in test setup
9
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Measurement methods
Ground Plate Method (GPM)
Circuit schematics for all three measurement setups are similar
Source circuits are almost same
Receiver circuits are different (physically)
Same GPM test setup for both HV-Cable and HV-Cable-Connector system
10
~R1F
R2P
R2N
U1N
U2,FE
Inner side of shield
Z1,εr1
Z2,εr2
NWA port1:
SourceNWA port 2
Receiver
Source-circuit
Inner-conductor
:
Far-end
ZT
Receiver-circuit:
Cylinder (Triaxial-Method)/
Injection (Parallel) lines (Line Injection Method)/
Copper-plate (Ground-Plate Method)
Near-end
R1P
RDamping
Outerside of shield
U2,NE
SHIELDT
SHIELD SHIELD
dVZ
I l
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Measurement methods
Ground Plate Method (GPM)
Test setup
11
R2F
R1FLine Injection Method
(Far-end configuration)
R2FR1F
Triaxial Method
RDamping
R1F
IINNER
+
VSHIELD
_ZT = VSHIELD/ (IINNER .lDUT)h= 65 mm
HV-Cable only
Inverted
Connector-box
HV-Cable-
Connector system
RDamping
R1F
lDUT
lBox
h= 65 mm hbox = 100 mm
Ground Plate Method (GPM)
Alternative
method for
measuring
Transfer
Impedance ZT
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Measurement methods
Ground Plate Method (GPM)
12
105
106
107
10810
0
101
102
103
Frequency [Hz]
ZT [m
Ohm
/m]
Comparison of LIM, Triaxial and GPM for HV-cables only
LIM
Triaxial TUDO
Triaxial Bedea
GPM
Triaxial tube
Line Injection Method
Ground Plate Method
Matched-Matched
termination
improves range
ZT-cable ≈ RDC-cable-shield
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Measurement methods
Ground Plate Method (GPM)
13
105
106
107
108
100
101
102
103
104
Frequency [Hz]
ZT [m
Ohm
/m]
ZT comparison of Connectors A,B and Dummy-box (Ideal)
ZT-Connector-A
ZT-Connector-B
ZT-Dummy-box
ZT-Cable
Ref.
Lesser contact-
points improve
shielding
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Measurement methods
Capacitive Voltage Probe (CVP) test
Using basic definition of ZT
14
(Ground) Copper plate
Near-end Far-end
ZLOAD
lbracket-bracket
h Vshield
ISOURCE
CVP
insulator
ISHIELD
SHIELDT
SHIELD SHIELD
dVZ
I l
CVP SHIELDV V
50
SOURCESOURCE
IN
VI
Z
lSHIELD
Contacts are
assumed to be perfect R= 0Ω
For unknown input
impedance/mismatched system, it can be measured using reflection
measurements using NWA
Longer DUT
length will ensure better RDC
measurements
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Measurement methods
Capacitive Voltage Probe (CVP) test
15
104
105
106
107
108
10-1
100
101
102
103
Frequency [Hz]
ZT [m
Ohm
/m]
ZT-GPM
ZT-CVP
RG58 (with shield-dia ‘D0’= 4.4mm; braid thickness
‘d’=0.15 mm; No. of braid filaments ‘n’= 5; No. of
carriers ‘N’= 24; Weave angle=21
CVP doesn’t require soldering matched
terminations in complex ways, but has
lesser measurable ZT
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
104
105
10610
-2
10-1
100
101
Frequency [Hz]
ZT [m
Ohm
/m]
Semi-rigid cable ZT using CVP
ZT-Semi-Rigid-L25cm
ZT-Semi-Rigid-L50cm
ZT-Semi-Rigid-L75cm
ZT-Semi-Rigid-L75cm-LF
ZT-SIM
Measurement methods
Capacitive Voltage Probe (CVP) test
16
Benefit:
For semi-rigid cables, very good shielded
cables CVP measures directly
T-SIM-RG-402
;1
sinh 1DCZ
jR
j
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Content
Introduction
Measurement methods
Simulation methods
Analytical models
Circuit models
Conclusions
17
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Braid parameters
Diameter of the
braidD0
Diameter of single
braid wired
Number of wires in
carriern
Number of carriers N
Weave angle Ψ
Conductivity σ
Simulation methods
Analytical Model
Using analytical model (Demoulin model) for ZT
18
103
104
105
106
107
108
10-1
100
101
102
103
Frequency [Hz]
ZT [m
Ohm
/m]
Shielded cable ZT model description vs. frequency
ZT = |Z
D|
ZT = |jL|
Zk = |k|
ZT model
ZT measured
_ _T Cable DC shieldZ R
1 2
_ 0
1
sinh 1T Cable
jZ R
j
3
4
_ 0
1*( )
sinh 1
j
T Cable SHIELD CABLE
jZ R j L k e
j
4
_ *( )T Cable shieldZ j L
ZT Dominant parts (1-4) in ZT
4
0
1( );
sinh 1
j
T CABLE HOLE BRAID
jZ R k e j L L
j
Aperture
Carrier N
Weave Angle Ψ
Single Braid-wire ‚n‘
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Simulation methods
Analytical Model
How ZT can be improved based on geometrical parameters of the shield?
19
Inner ConductorBraid Structure
Outer Shield
Insulating Material
d
D0
Aperture
Carrier N
Weave Angle Ψ
Geometrical parameters of shield
Single Braid-wire ‚n‘
103
104
105
106
107
10810
0
101
102
103
Frequency [Hz]
Zt [m
Ohm
/m]
Effect of braid wire thickness on Zt
d = 1.0mm
d = 1.2mm
d = 1.4mm
d = 1.6mm
d = 1.8mm
d = 2.0mm
Braid thickness has major
impact on how ZT behaves at low frequencies as ZT = RDC
103
104
105
106
107
10810
0
101
102
103
Frequency [Hz]
Zt [m
Ohm
/m]
Effect of Weave angle variation on Zt
weave angle 20
weave angle 25
weave angle 30
weave angle 35
weave angle 40
Inductance is directly dependent on weave
angle. Changing weave angle means changing inductance of the shield thus
major impact is at higher frequencies
where inductance are dominant in ZT
Break frequency
decreases with
increasing shield
thickness
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Simulation methods
Circuit models
Combination of analytical
and circuit models
give more realistic
prediction of shielding
behavior
Advantages: Possible to..
Add TL models for
connecting cables, to
predict realistic
measurement results
Add to other modules, for
complex system analysis
20
(LCOAX/2)
CCOAX
(LCOAX/2)(LCC/2)
CCC
(LCC/2)
VSOURCE
~RPORT1
(LCC/2)
CCC
(LCC/2)
R1F
T-cellT-cellSOURCE
PORT
Inner-shield
Inner-
conductor IIN-CCT
ISOURCE
ISHIELD
RPORT2
RECEIVER
PORT
(LSG/2)
CSG
(LSG/2)
~RGND-Contact
RDAMPINGOuter-
shield
Ground plane
_ +
IOUT-CCT
VT
0.1Ω
104
105
106
107
108
109
10-1
100
101
102
103
Frequency [Hz]
ZT [m
Ohm
/m]
Verification of ZT model for HV-cable only
ZT model 25mm
2
ZT QUCS 25mm
2
ZT meas 25mm
2
Circuit model
Demoulin
Measured
VT = ISHIELD.ZT-model
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Content
Introduction
Measurement methods
Simulation methods
Conclusions
21
technische universität
dortmund
Abid Mushtaq, Katharina Hermes, Stephan Frei – Kleinheubacher Tagung 2015
Comparative Study of Transfer Impedance (ZT) Measurement Methods and Simulation models to Analyze Shielding
Behaviour of High Voltage Cables in Electric Vehicles
Conclusions
Summary
Overview
Comparative study of ZT measurement methods and Simulation methods for
shielding analysis of HV cables used in EVs
Measurement methods
Existing methods like Triaxial and Line Injection Methods
Ground Plate Method (GPM)
Capacitive Voltage Probe (CVP) Method
Simulation methods
Analytical models
Circuit models
Applications:
Component level shielding analysis of shielded cables and connectors
Further integration of proposed simulation methods into complex system
simulations
Correlation with Antenna measurements
22
Fakultät für Elektrotechnik und Informationstechnik
Arbeitsgebiet Bordsysteme
technische universitätdortmund
Thanks for your attention!
M.Sc. Abid Mushtaq
ACKNOWLEDGMENT
The reported R+D w ork was carried out w ithin the CATRENE project CA310 EM4EM (Electromagnetic Reliability and Electronic Systems for Electro Mobility). This
particular research is supported by the BMBF (Bundesministerium fuer Bildung und Forschung) of the Federal Republic of Germany under grant 16 M3092 I.