Professor : Stig Munk-Nielsen
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1.
Department on Energy technology (1page)
2.
CORPE / IEPE – what is it ( 5 pages)
3.
Why and what are we testing? (10 pages) a.
WT: Full Power and DFIG converters b.
Power Modules c.
Short history – of power cycling
4.
Working principle of first test bench's at AAU (18pages) a.
Emulate work point of DFIG b.
Failure mechanisms c.
Focus on bond wire failure d.
Measurement of Vce (off line) e.
After failure – bond wire status
5.
Power cycling of power modules second test bench (13 pages) a.
Power system b.
Measurement of Vce (on line) c.
Real time estimation of Tj d.
What failure modes did we find and how to identify them
6.
What we want to do next (2 pages)
7.
Conclusion (1 page)
8.
Acknowledgments (1 page)
9.
List of publications (1 page)
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Introduction: Department of Energy Technology
Energy
Storages
PRIMARY
FUEL
SOLAR
ENERGY
HEAT
LOADS
Energy
Storages
CHP
FACTS/CUPS
COMPEN-
SATOR
Status 2014
• 30 Professors, Associate,
Assistant
• 90 PhD, 250 BSc and MSc students
• 20 Guest Researchers
• 10 Research Assistants
• 15 Technical staff
[ [
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Overall goals
By obtaining high-reliability power electronic systems for use in all fields of electrical applications used both in design and operation where the main drivers are cost, efficiency, reliability, predictability, lower operational and maintenance costs during the lifetime.
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Work package content:
(Objects: Power Module’s kW-MW, Capacitor’s)
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Man power
• 11 Ph.D’s
• 12 Post Doc Years
• 25 Man Year additionally - University and industry
• 5 years activity
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Industry focus
System integration
Business integration
Innovative
Product development
Research and
Development of reliable
Power electronics
(CORPE)
Fundamental technology
Devices, and physics
Innovative platform:
Research and development of
Intelligent Efficient Power Electronics
(IEPE)
University focus
8
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a.
b.
c.
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WHY do lifetime tests
•Larger and larger wind turbines •Increase in failure rate http://www.wind-energy-the-facts.org/documents/download/Chapter1.pdf
http://www.sandia.gov/wind/2009Reliability/PDFs/Day1-17-PeterTavner.pdf
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WHY do we do this work.
•Converter causes approximately 15 % of wind turbine failures
By S. Müller, M. Deicke, and Rik W. De Doncker
Doubly fed induction generator systems for wind turbines
IEEE INDUSTRY APPLICATIONS MAGAZINE Vol. 8, pages 26–33, 2002 http:// www.sandia.gov/wind/2009Reliability/PDFs/Day2-13-MichaelWilkinson.pdf
.
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The Application : Wind turbines – DFIG and Full Scale
The OBJECT
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1)
(1993-1995)
(LESIT
Leistung Elektronik Systemtechnik Informations Technologie)
Number of cycles to failure as function of ΔT j with T m
(mean temperature).
Testing focus: bond wire reliability of IGBT modules in traction application
Testing samples: 300A/1200V single switch IGBT modules from different suppliers
Testing conditions: ΔT j
: 30°C to 80°C,
Failure criterion: 5% increase of V
CE
V
GE
: 15V, current load : 240 to 300A, t on
Measurement method: periodical static measurement of V
CE
:0.6 to 4.8s, and t off
: 0.4 to 5s
Figure source: U. Scheuermann and U. Hecht, “Power cycling lifetime of advanced power modules for different temperature swings,” in Proc. PCIM Europe
2002, pp. 59-64.
1) : M. Held, P. Jacob, G. Nicoletti, P. Scacco, M. H. Poech, “Fast power cycling test for IGBT modules in traction application,” in Proc. Power Electronics and
Drive Systems 1997, 425-430.
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LESIT Project Power Cycling Testing 1)
Swiss Federal Institute of Technology, ETH Zurich.
Fraunhofer, Itzehoe Germany, 1997
1) Held, M.; Jacob, P.; Nicoletti, G.; Scacco, P.; Poech, M.-H., "Fast power cycling test of IGBT modules in traction application," Power Electronics and Drive Systems, 1997. Proceedings., 1997
International Conference on , vol.1, no., pp.425,430 vol.1, 26-29 May 1997 doi: 10.1109/PEDS.1997.618742
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Intro: PWM Switching Based Power Cycling Testing
(2011)
Vanessa Smet, V., F. Forest, et al., "Ageing and failure modes of IGBT modules in high-temperature power cycling," IEEE Transactions on Industrial Electronics,
58(10): 4931-4941. 2011
More realistic testing (i.e. switching, high voltage, dynamic loss) under PWM switching conditions
Testing with inverter legs in a back-to-back configuration 600V/200A IGBT modules for automobile traction application
No online measurement of V
CE
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Problem statement 1)
• Is it possible to design a test bench capable of stressing the power modules in the same manner as in an actual wind turbine with a
DFIG setup?
• And is it possible, by using the test bench, to measure a physical parameter, which will indicate wear-out of the IGBTs, in order to predict failure of the IGBT module?
1) LIFETIME ESTIMATION OF HIGH POWER IGBT MODULES, Power Electronics and Drives, PED3-931, Master Thesis, 2009-2010
The Faculty of Engineering, Science and Medicine Institute of Energy Technology, Aalborg University
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Innovative measuring system for wear-out indication of high power IGBT modules . / Nielsen, Rasmus Ørndrup; Due, Jens; Munk-Nielsen, Stig.
Proceedings of the 3rd IEEE Energy Conversion Congress and Exposition (ECCE 2011). IEEE Press, 2011. p. 1785-1790 .
More realistic testing (i.e. switching, high voltage, dynamic loss) under PWM switching conditions
Testing with inverter legs in a back-to-back configuration 1700V/1000A IGBT modules for WT application
Online measurement of V
CE
2:Lifetime investigation of high power IGBT modules. / Due, Jens; Munk-Nielsen, Stig; Nielsen, Rasmus Ørndrup.
Proceedings of the 14th European Conference on Power Electronics and Applications (EPE 2011) . IEEE Press, 2011. p. 1-8.
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Power electronics reliability test
Laboratory test Field test
Destructive test Non destructive test
Life time test Marginal test
Operation test
Normal/ accelerated life test
Step stress test
Storage test
Storage test
Thermal cycling
Active TC
Power cycling test
Proposed
P sw
+ P cond heating
AC current
Offline characterisation
Real time monitoring Passive TC
P cond heating
Pulsating
DC current
PC minute
Conventional
PC second
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How we determine lifetime and investigate cause of failure
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a.
b.
c.
d.
e.
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Working principle of test bench – Emulating Work Point of DFIG
• Current source must be realized
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The IGBT modules
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Specifications
• Lifetime model
•T
J-max
=150 o C.
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Initial working point
• Starting from DFIG full load operating point
• Expected lifetime 5200 kcycles = 7.1 days for the DUT diodes
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Failure mechanisms http://www.weibull.com/hotwire/issue21/hottopics21.htm
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Failure mechanisms
• Bondwire liftoff
• Aluminum reconstruction
Mauro Ciappa
Selected failure mechanisms of modern power modules
Microelectronics Reliability 42, pages 653–667, 2002
Mauro Ciappa
Selected failure mechanisms of modern power modules
Microelectronics Reliability 42, pages 653–667, 2002
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Failure mechanisms
• Solder failures
Mauro Ciappa
Selected failure mechanisms of modern power modules
Microelectronics Reliability 42, pages 653–667, 2002
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State of the art
• Expected increase in V
CE before failure:
M. Held, P. Jacob, G. Nicoletti, P. Scacco, and M Poech
Fast power cycling test of igbt modules in traction application
International Conference on Power Electronics and Drive Systems, pages 425–430, 1997
M. Bartram, J von Bloh, and Rik W. De Doncker
Doubly-fed-machines in wind-turbine systems: Is this application limiting the lifetime of igbt-frequency-converters?
Power electronics specialists conference 35, Aachen, pages 2583–2587, 2004
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Hypothesis
• Active power cycling
• Passive power cycling
• We use Active power cycling, so the stress is on the Bondwires.
•Bondwire liftoff will result in discrete steps in V
CE
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Hypothesis
• How much will V
CE increase?
• How many bondwires?
• 7 – 13 bondwires corresponds to 1.5 %, unless other wear-out mechanism also is present
2.4
2.3
2.2
2.1
2
0
2.9
2.8
2.7
2.6
2.5
2.15
2.1
2.05
2
0 5 10 15
Number of Destructed bondwires [-]
20 25 5 10 15
Number of Destructed bondwires [-]
20
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25 30
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Design of V
CE measuring system
•Must be able to measure with a great accuracy since only 30 mV change is to be expected.
• Must be able to measure automatically with a time interval of maximum 15 minutes
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Investigation of the relay approach
• Offline measuring method.
• Direct measurement.
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Realization of the relay approach
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Verification of V
CE measuring system
• Verification of Control-High elements
- 10 x measurements done within a minute
• All other components in the test bench shares similar accuracy
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Lifetime investigation of modules – working point adjustments
• Three test periods have been conducted.
• The first test was used as a running-in test
Data for the used working points
Number of calculated cycles to destruction
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Lifetime investigation of power modules
IGBT
The IGBT lasted 4748 kcycles, around 9.2 days, in the working point.
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Investigation of destroyed Infineon modules
• Test period 2
5 loose bondwires
Change in V
CE caused by bondwire lift-off:
Hypothesis = 10.5 mV
Measured = 12 mV
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Investigation of destroyed Infineon modules
• SEM investigation
•3D CT scan
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a.
b.
c.
d.
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Acceleted test. Second Generation:
Motivation: Power electronics devices – major cause of failure.
• Technology of power electronic device can be improved – more reliable devices
• Knowing and understanding indicator parameters about status of the device:
1. System can be adapt to new operating conditions.
2. Device can work more efficiently
40

Acceleted test.
How ?
41

Old setup vs Gurli I
Old Setup Gurli I
42

Gurli I
Power supply for Gurli I
63A max a b c g
Danfoss VLT
27 kVA
380-500V
L f
C f
32A max
1:2.2
20A max
400V max
100 Hz
21 kVA
880V max
Accelerated test setup
Operating points
Parameter
V
DC-Link
V acoss inductor
I inductor f out f sw
Coolant temperature
Lab temperature
Value
1000V
315V rms
890A peak
6Hz
2.5KHz
80 ± 1 o C
20 ± 2 o C
25A max
+
2mF
1100V
DC
1244V
DC,max
_
43

Vce measurement
Offline - Reed Relay Online - Double Diode
44

Comparison
Offline measurement
(Shows ONLY wear out)
Reed relay
Capable online measurement
(Shows wear out + status of device)
Double diode
Mechanical devices (Relay) No mechanical devices
No perturbation at gate signals No perturbation at gate signals
45

Measuring method:
46

Result-Vce Reed Relay
47

Result 1st test- Vce Double Didoe
Offline measurement – same performance as previous board
48

Online measurement
49

Estimation of Tj
50

Wear Out Tests
51

Real time estimated junction temperature
52

What we want to do next ?
53

Verification of Tj with thermal camera measurements:
54

What information can be extracted from Vce, Ic ?
Voides size of metallization on diode is increasing with number of cycles.
55

Conclusion
• A bench’s capable of stressing IGBT modules in a similar way as in an actual application
• An innovative high accuracy V
CE measuring system has been developed.
• Automatic measuring routines has been implemented allowing non-stop testing until destruction of IGBT modules.
•Ability to estimate Tj real time looks to be possible
•Ability to do post analysis of tested power modules
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Acknowledgements : Who did the work?
• Bjørne Rannestad, kk
• Angel Ruiz de Vega, et-aau
• Ionut Trintis, et-aau
• Szymon Michal Beczkowski, et-aau
• Pramod Ghimire, et-aau
• Kristian Bonderup Pedersen, physics-aau
• Jens Due, former et-aau
• Rasmus Ørndrup Nielsen, former et-aau.
• Paul Thøgersen, kk
• And all the people who made the work possible – by helping with hardware.
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Further reading:
1.
Improving reliability of power converter using an online monitoring of IGBT module, P.Ghimire, A.de
Vega, S.Beczkowski, B.Rannestad, S.Munk-Nielsen, P.Thøgersen, Special journal issue on IEEE
Industrial Electronics Magazine 2014
2.
An online Vce measurement and temperature estimation method for high power IGBT module in normal
PWM operation, P.Ghimire, A.de Vega, S.Beczkowski, B.Rannestad, S.Munk-Nielsen, P.Thøgersen,
IPEC2014
3.
A real time measurement of junction temperature variation in high power IGBT modules for wind power converter application, P. Ghimire, A. R. de Vega, K. B. Pedersen, B. Rannestad, S. Munk-Nielsen, P.
Thøgersen, CIPS 2014
4.
Dynamic Performance of Grid Converters using Adaptive DC Voltage Control Ionut Trintis, Josep
Guerrero, Stig Munk-Nielsen, Paul Bach Thøgersen, EPE2014
5.
A review on real time physical measurement techniques and their attempt to predict wear-out status of
IGBT. Ghimire, P.; Beczkowski, S.; Munk-Nielsen, S.; Rannestad, B.; Thogersen, P., ECCE 2013
6.
A Real Time Vce Measurement Issues for High Power IGBT Module in Converter Operation. P. Ghimire,
A. R. de Vega, S. Munk-Nielsen,B. Rannestad, P. Thøgersen, IFEEC 2013, Nov. 3-6
7.
Test Setup for Long Term Reliability Investigation of Silicon Carbide MOSFETs Nick Baker, Stig Munk-
Nielsen, Szymon Bęczkowski, EPE 2013, Lille, France
8.
Efficiency and Reliability Improvement in Wind Turbine Converters by Grid Converter Adaptive Control
Ionut Trintis, Stig Munk-Nielsen, Flemming Abrahamsen, Paul Bach Thøgersen, EPE 2013
9.
J. Due, R. Ø Nielsen,S. Munk-Nielsen, ‘Lifetime Investigation of High Power IGBT Modules’ Accepted for publication at , 14 th European Conference on Power Electronics and Applications, 2011, 30 August,
Birmingham, UK
10. Innovative measuring system for wear-out indication of high power IGBT modules. Nielsen, Rasmus
Ørndrup; Due, Jens; Munk-Nielsen, Stig. Proceedings of the 3rd IEEE Energy Conversion Congress and
Exposition (ECCE 2011). IEEE Press, 2011. p. 1785-1790 .
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