simulating emcemi effects for high-power inverter systems
TRANSCRIPT
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Simulating EMC/EMI Effects for High Power Inverter Systems
Emmanuel Batista Alstom
PearlVincent Delafosse, Ryan Magargle Ansoft [email protected]@[email protected]
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Acknowledgments
This work has been based on the work of Emmanuel Batista, J.M. Dienot, M. Mermet-Guyennet
Special Thanks:
P. Solomalala (Pearl/Alstom)
O.Roll, X. Legoar, D. Prestaux,
X. Wu, M. Rosu, S. Kher (Ansoft)
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Pearl: Power Electronics Associated Research Laboratory
Models-Simulation-FabricationEMCSolve multi-domain/temps/structure
Passive ComponentsActive Components
Packaging
Research
and Validation of technologies Development
and validation of prototypes
Viability
and maintenance
Design of methods
for conception
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Motivation
High power IGBT based inverter systems have specific EMC/EMI requirements
The prediction of EMC/EMI fields is very difficult . Physical prototyping can result in long design cycles
Simulation tools can help with the use of several techniques
The physical quantities in the inverter that need accurate simulation are:
Quantity of current going through the conductors
Frequency dependent parasitics (RLC) between conductors
IGBT characterization curves
Power dissipation
Emitted fields
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Overview
Introduction to the power study
Static electromagnetic field study
Parasitics extraction
IGBT characterization
System simulation
Emitted fields
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AM3~
Traction SupplyPantograph Traction Motor
Introduction
Inverter Inverter LegIGBT Module Top Row
These
power converters
are used
in high
speed trains (TGV)
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Introduction
6.5kV IGBT Module Characteristics
Baseplate
CollectorEmitter
IGBT Chips
Diode Chip
6.5kV6.5kV--600A 600A Module Module
24 IGBT and24 IGBT and
12 Diode Chips12 Diode Chips
Dielectric Gel
Packaging
Ceramic
Substrate
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Introduction
6.5kV IGBT Module Analysis
Include package in IGBT performance
Find DC current distribution
Find switching currents for power dissipation
Use power dissipation to determine environmental electromagnetic fields
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Model design developed
at
Alstom/Pearl
IGBT Module Pack 3D accurate model
Parameters Extraction
Electromagnetic (EM) study
Design and Couplings Model
IGBT Model
Tridimensional IGBT pack model and EM study
Parasitic model extraction
IGBT circuit model
Far Field Study
Far Field Study for Electric Field EM
Introduction
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Different
Modeling
techniques will
be
seen
Tridimensional IGBT pack model and EM study
Parasitic model extraction
IGBT circuit model
Far Field Study for Electric Field EM
Finite Element MethodFinite Element Method
Boundary Element Method
Boundary Element Method
Finite Element
Method
Finite Element
MethodSystem SimulationSystem Simulation
Introduction
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Overview
Introduction to the power study
Static electromagnetic field study
Parasitics extraction
IGBT characterization
System simulation
Emitted fields
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ElectroMagnetic Study
Module layout
verification
The module contains
8 IGBTs
in parallel: does
each
IGBT receive
the same
amount
of current?
If the current
flows
un-evenly, this
will
cause mechanical
stress and reliability
issues.
Electromagnetic
simulation is
required. We
use Maxwell3D.
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ElectroMagnetic Study
The layout
in imported
from
the CAD tool
The DC solver
is
used
The input current
(600 A) is
defined
The sink
(return current
path) is
defined
Outputs: conduction path
and current
distribution
600 A Sink
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ElectroMagnetic Study
The structure is
meshed
using
automatic
and adaptive meshing
Current
DistributionIGBTs
on, Diodes off
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ElectroMagnetic Study
The end IGBTs
see
less
current
than
the center ones.
This can
cause reliability
issues as the center IGBTs
will
be
overloaded
An optimization
of the copper
tracks
can
be
made in order
to equalize
the currents.
Igbt1a and Igbt4a have the highest
quantity
of current
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Overview
Introduction to the power study
Near field electromagnetic study
Parasitics extraction
IGBT characterization
System simulation
Emitted fields
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Parasitics Extraction
Once the layout
is
optimized, the next
step
is
to extract
the resistance, inductance and capacitance (RLC) parameters
of the package.
For this
we
use the boundary
element
method
in Q3D
Example
for two
conductors
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Parasitics Extraction
Frequency Dependent Effects
Integrated power-electronic modules exhibit frequency-dependent behavior due to eddy current and skin effects.
In these cases, it may not be sufficient to rely on resistance and inductance extracted at a single operating frequency
For example, coax
conductors:
Low Frequency High Frequency
Samegeometry
Different frequency
=
Different Parasitics
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Extracting parameters is straightforward as the nets are automatically assigned.
Parasitics Extraction
Gate
net
Emitter
net
Collector
net
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How do we set up the frequency sweep?
Through Nyquist
sampling, we know that to capture a time step of Ts, we need to obtain frequency domain information up to:
For a time domain waveform with a risetime
of 80 ns, in order to capture the ringing in the time domain, we would want to capture at least 4 samples during this risetime. This implies a sampling time of 20 ns
We
need
to solve
up to 50 MHz (= 1/20ns)
stF = 2
1max
Parasitics Extraction
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Parasitics Extraction
The simulation outputs consist of the RLC matrices for different
frequencies
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Parasitics Extraction
How do we
use the parasitics in the circuit simulator?
Basic methodology:
Compute N-port S parameters (frequency sweep)
Convert this into information that circuit simulator understands
Circuit simulator performs inverse FFT to find impulse response
Convolution is used to produce time-domain results
=== t dxtstxtstyjXjSjY )()()()()()()()(
)())(()()1(
tkxtknstnyn
Nnk
=
V
o
l
t
a
g
e
876.5m
1.1
900.0m
950.0m
1.0
1.1
1.1
17.55u 20.00u18.00u 18.50u 19.00u 19.50uTime (Seconds)
Voltage versus Time Using Different 2D Extractor Mode
VM11.V [V] VM_Linear_1Hz_Model.V [V] VM_Linear_1MHz_Model.V [V] VM_Frequency_Model.V [V]
Damping
Phase
Copper shield
Silicon
Polyethylene
Silicon
Copper
Copper shield
Silicon
Polyethylene
Silicon
Copper
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Overview
Introduction to the power study
Near field electromagnetic study
Parasitics extraction
IGBT characterization
System simulation
Emitted fields
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SIMPLORER 8
Simplorer 8 is
a circuit simulation tool
for solving
multi-domain
lumped
circuit problems.
Link projects
together
to achieve
dynamic
linking
of multiple simulations on a single sheet.
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SIMPLORER 8
Modeling
New Parametrization
tool for IGBT
Enhanced SMPS Library -
Over 450 New VHDL-AMS DC/DC Converter Models in SMPS
Digital Co-simulation
Spice Pspice integration
Enhancements
to individual
models
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System Integration
How do we
import the results
from
Q3D?: Q3D dynamic link
2 Types of links: Single Frequency
or Frequency
dependent
No need
to manually
import output file
Simplorer incorporates
directly
the Q3D project
If some
results
are not available, Simplorer dynamically
launches
Q3D
Parameters
and variables can
be
passed
between
S8 and Q3D
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System Simulation
IGBT
Wattmeter
VcVg
Power Module from
Q3Dfor board
parasitics
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IGBT Characterization
Accurate
models
of the semiconductors
are needed
to achieve
a good circuit simulation
Simplorer 8 offers
a parameterization
tool
for IGBTs
The user needs
to import the data from
the datasheet
2 types of models
are available
in Simplorer 8: Basic Dynamic
and Average
Dynamic
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IGBT Characterization
Objective Average Basic Dynamic
Advanced Dynamic
DC characteristics
-
Transfer characteristic
Ic(Vge) accurate-
Output characteristic
Ic(Vce) accurate in the regions of voltage and current saturation-
Intrinsic temperature dependencyElectrical Dynamics
- Considered
Thermal Dynamics
Partial Fractional orContinued Fractional
Capacitance Models
- Default C(V)
Full access to the C(V) characteristics
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IGBT Characterization
Sub circuit of the basic dynamic IGBT model
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SheetScan
IGBT Characterization
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Once all the curves
and data are entered, start
extraction
The tool
fits
the data to the internal
Simplorer model using
Genetic
Algorithm
IGBT Characterization
Characterization toolComponent dialog
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IGBT Characterization
Test Circuit
499.90 499.95 500.00 500.05 500.10 500.15 500.20 500.25 500.30Time [us]
0.00
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C
E
-15.00
-10.00
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M
2
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[
V
]
-10.00
0.00
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R
2
.
I
[
A
]
Ansoft Corporation Simplorer1switch_on
Curve InfoU1.VCE
TRVM2.V
TRR2.I
TR
999.00 999.50 1000.00 1000.50 1001.00 1001.50 1002.00 1002.50 1003.00Time [us]
0.00
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U
1
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V
C
E
-15.00
-10.00
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0.00
5.00
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15.00
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M
2
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[
V
]
-10.00
0.00
10.00
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2
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[
A
]
Ansoft Corporation Simplorer1switch_offCurve Info
U1.VCETR
VM2.VTR
R2.ITR
Switch on
Switch off
Vce
Vce
Ic
Ic
rise time= 40 sfall
time = 50
s
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System Simulation
2500 Voltage Source
Line Resistance and Line Inductance
Vg: Gate
Voltage (+/-15V)
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System Simulation
Issue:
Accurate
simulation of the switching
of the IGBTS requires
very
small
time steps
(hmin
= 10ps)
System simulation requires
long time step
(t = 5ms)
Simplorer allows
the user to dynamically
change hmin
and hmax
using
State Graphs.
When
the switching
has occured, the time step
can
be
increased.
Switching Steady state Switching
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System Simulation
Vce, Vge, Ic
over time (Igbt3b)
Reduce Time Step HMin
I
c
V
c
e
-
V
g
e
VgeVce
Ic
Ic
VgeVce
Ic
VgeVce
Vge
Vce
Icg
c
e
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Vce
Vg
Vge
Ic
Power
The power pulse duration is much smaller than the rise/fall time
of Ic
and Vce
System Simulation
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System Simulation
Instantaneous power level through Igbt3a
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System Simulation
Power levels of the full set of IGBTs
on switch on
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System Simulation
Igbt1a and Igbt4a receive the highest power levels.
This is consistent with the DC Conduction Maxwell3D solution
Igbt1a
Igbt4a
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System Simulation
The fundamental frequencies of the power range between 16 and 54 MHz
t @ Pmax(s)
t @ P
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System Simulation
FTT of the power through Igbt1a
Most of the power level is below 110 MHz
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Emitted Fields
There is
very
high
power going
through
the IGBTs
(almost
60 000 W in this
study) during
a very
short period
of time (60 ns). This switching
can
cause EMI issues in the inverter, but also
in the surrounding
equipment
To be
answered
using
the finite
element
method
in HFSS:
Will the module radiate?
Are the field
levels
surrounding
the module within
mandated
levels?
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Emitted Fields
The power pulse in the IGBTs
have most
of the energy
in the 16-
110 MHz range.
The largest
metallic
piece
is
150 mm in the module
There is
a chance of having
radiation if
< 4 * L = 600 mm. This is
for a frequency
of 500 MHz.
By itself, the module will
not radiate.
However, the power module in the train is
surrounded
by other
metallic
objects
than
can
be
fairly
large. These
objects
can
cause the radiation of electric
fields
during
switching.
Maxwells Equations
div D = curl E = -B/tdiv B = 0
curl H = J + D/t
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Emitted Fields
Regulators
impose maximum levels
of electric
fields
close to electric
equipment.
In the 10-110 MHz range:
Emax=61V/m
Exposure
limits
defined
by European
Community
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Emitted Fields
Each
IGBT pad is
excited
using
lumped
ports
The port lies between
the collector
and emitter
pads
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Emitted Fields
The structure is
discretized
with
adaptive meshing. The meshing
frequency
is
100 MHz
The frequency
sweep
ranges from
15MHz to 120 MHz
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Emitted Fields
For each
frequency, the power amplitude is
entered
Spectrum (MHz)
Power (W)
E field at 1m for 1000w (V/m)
E field at 1m (V/m)
16.52892562 21439.97604 2.6312 56.4128649733.05785124 8635.09049 2.7994 24.1730723249.58677686 5579.619715 2.8731 16.030805466.11570248 4131.16773 3.063 12.65376676
82.6446281 3276.823585 3.4045 11.1559458999.17355372 2712.888158 3.8924 10.55964586115.7024793 2308.359536 4.4861 10.35553171
132.231405 2022.75744 4.905 9.921625241
Spectrum from
Simplorer
Outputs from
SimplorerInputs for HFSS
Outputs From
HFSS(normalized
results)Fields Levels
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Emitted Fields
The E field
is
very
localized
close to the module even
at
100 MHz
However, the very
high
power can
lead
to large values of E field
even
far from
the module
This design is
fine at
110MHz.
mag
E @ 100 MHz, Power = 10 000W
Spectrum (MHz)Power
(W)Spectrum (MHz)Power
(W)E field at 1m
(V/ m)E field at 1m
(V/ m)115.7024793 2308.359536115.7024793 2308.359536 10.3555317110.35553171
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Conclusion
We have seen that the combination of several simulation techniques can give a good approach to EMC/EMI issues, both in conduction and emission modes
Accurate prediction requires the use of Finite Element Methods, Boundary Element Methods, System Simulation along with Accurate Component
Characteristics
Package traces need optimization to balance current distribution
The simulated module does not radiate for the given harmonics, and is within regulated near field field limits.
Simulating EMC/EMI Effects for High Power Inverter SystemsAcknowledgmentsPearl: Power Electronics Associated Research LaboratoryMotivationOverviewIntroductionIntroductionIntroductionSlide Number 9Slide Number 10OverviewElectroMagnetic StudyElectroMagnetic StudyElectroMagnetic StudyElectroMagnetic StudyOverviewParasitics ExtractionParasitics ExtractionParasitics ExtractionSlide Number 20Parasitics ExtractionParasitics ExtractionOverviewSIMPLORER 8SIMPLORER 8System IntegrationSystem SimulationIGBT CharacterizationIGBT CharacterizationIGBT CharacterizationSlide Number 31IGBT CharacterizationIGBT CharacterizationSystem SimulationSystem SimulationSystem SimulationSlide Number 37System SimulationSystem SimulationSystem SimulationSystem SimulationSystem SimulationEmitted FieldsEmitted FieldsEmitted FieldsEmitted FieldsEmitted FieldsEmitted FieldsEmitted FieldsConclusion