New Passive Devices in Power Electronics -Nice to Have Or a MUST?

New Passive Devices in Power Electronics -Nice to Have or a MUST?-

Dr. Petar J. Grbović Huawei Technologies Düsseldorf GmbH Nuremberg Center of Power Electronics and Drives C-PED Lab. Roma TRE Université, Rome, Italy OUTLINE

1. Motivation & the Facts A. What we have been doing in last 70 years? B. We do not need Inductors and Capacitors in Power Converters? 2. Key Issues We are Facing and what Do We need in future? 3. What else beside Magnetics and Capacitors 1. Drivers 2. Sensors

PCIM 2018, June 5-7, Nuremberg -2- Motivation & the Facts

PCIM 2018, June 5-7, Nuremberg -3- …Motivation & Facts…  New Power Converters  Extreme Efficiency . Extreme Power Density & Specific Power  Last 20 years, PCIM, PESC, ECCE…. Focus on New Power Devices only

PCIM 2018, June 5-7, Nuremberg -4- …….Today…  “Yesterday”: 10-15 years ago  Eff. 96%...Very Good Converter  “Today”: Eff. >99%... Can we go beyond?

PCIM 2018, June 5-7, Nuremberg -5- …Motivation & Facts… It looks like Magnetics and Capacitors are now a Bottleneck .  Why we did not invest more in Magnetics and Caps? A. History of Power Converters B. Our Perception…Move faster & all our problems are solved

PCIM 2018, June 5-7, Nuremberg -6- History of Power Converters

PCIM 2018, June 5-7, Nuremberg -7- Long time ago…Yesterday…  Long time ago, static power conversion was simple and “primitive”….no yet power electronics

PCIM 2018, June 5-7, Nuremberg -8- …Development of Power Converters…  Long time ago, static power conversion was simple and “primitive”….no yet power electronics

 Heinrich Hertz's oscillator, 1887…  “Static “ Resonant Power Converter  Electromechanical switch

PCIM 2018, June 5-7, Nuremberg -9- …Development of Power Converters…  Long time ago, static power conversion was simple and “primitive”….no yet power electronics

 Tesla’s high frequency high voltage transformers for wireless power transmission, 1890s  Multi-resonant Static Converter

PCIM 2018, June 5-7, Nuremberg -10- …Development of Power Converters…  Very first controlled power converter was mercury arc rectifier developed in 1902 by Peter Cooper Hewitt.

Mercury-arc Siemens 560V 1300A GE hydrogen thyratron for valve Mercury-arc valve radar applications

PCIM 2018, June 5-7, Nuremberg -11- …Development of Power Converters…  Very first controlled power converter was mercury arc rectifier developed in 1902 by Peter Cooper Hewitt.  General Electric Company and engineer Alexanderson developed first controlled inverter to drive a three-phase motor in 1934

PCIM 2018, June 5-7, Nuremberg -12- …Development of Power Converters…

 The Key Question was not: How efficient and small the Converter is?  The Key Question was: Does it work and if does for how long it will work?

PCIM 2018, June 5-7, Nuremberg -13- …Development of Power Converters…  1947, Shockley invented BJT 1947…. Nobel Prize in Physics (1956)  1956, First silicon controlled rectifier (SCR)

A replica of the first bipolar transistor High power SCR

PCIM 2018, June 5-7, Nuremberg -14- …Development of Power Converters…

 The Key Question was not: How efficient and small the Converter is?  The Key Question was: Does it work and if does for how long it will work?

PCIM 2018, June 5-7, Nuremberg -15- …Development of Power Converters…  From 1950s to 1980s SCR, Power BJT and Power MOSFET  That was time to start thinking about new magnetics…but not much

PCIM 2018, June 5-7, Nuremberg -16- …Development of Power Converters…  Invention of Insulated Gate Bipolar Transistor-IGBT at the end of 1970s and begin of 1980s  The IGBT solved all the problems of BJT and MOSFET  What about magnetics and caps?

PCIM 2018, June 5-7, Nuremberg -17- …Development of Power Converters…  Super-Junction Si MOSFET invented in 1990s.  CoolMOS  MDmesh™  Magnetics & Caps are more & more critical, but not in focus yet!

PCIM 2018, June 5-7, Nuremberg -18- …Development of Power Converters…  End of 20 century, fresh blood is in the game SiC SBD, SiC JFET, SiC MOSFET, GaN HEMT  Again, the focus is only on devices, not on Magnetics & Caps!

PCIM 2018, June 5-7, Nuremberg -19- …….Today…  Today, thanks to introduction of the IGBT and the SJ- MOSFET, power electronics is part of our life  Home appliance, audio/video, communication…..  Industrial Applications….  Transportation…  Wherever we need to control power flow without (significant) losses, we have to use power electronics.....  Invention of the IGBT has contribution of >20 trillion (1012) US$ to global economy due to energy saving!

PCIM 2018, June 5-7, Nuremberg -20- …….Today…  Today, Even politicians are talking about Power Devices

PCIM 2018, June 5-7, Nuremberg -21- …….Today…  Today, Even politicians are talking about Power Devices

PCIM 2018, June 5-7, Nuremberg -22- …….Today…  Today, Even politicians are talking about Power Devices  But, did you see any politician talking about Magnetics & Capacitors?

PCIM 2018, June 5-7, Nuremberg -23- …….Today…  Even politicians are talking about WBG Devices  But, did you see any politician talking about Magnetics & Capacitors?

PCIM 2018, June 5-7, Nuremberg -24- ...Do we need Passives?… -Our Perception-

PCIM 2018, June 5-7, Nuremberg -25- …Do we need Passives?…

The Main “Four Elements” of a power converter 1) A Matrix of Switches (Power Semi…) 2) A bunch of Inductors, Transformers and Capacitors (and Resistors ) 3) Control Circuitry 4) Central Control Intelligence (S/W)

PCIM 2018, June 5-7, Nuremberg -26- …Do we need Passives?…

 ySW t  V ht  jdTSW .....  ....LOUT  0 j0

PCIM 2018, June 5-7, Nuremberg -27- …Do we need Passives?…

 xSW t  I L ht  jdTSW .....  ....CIN  0 j0

PCIM 2018, June 5-7, Nuremberg -28- …Do we need Passives?…

2-L 3-L 5-L 7-L 0 i  1

0,8

V  k 0,6 L    L OP OUT 0,4 fSW 0,2

0 Normalized Current Ripple Current Normalized 0 0,2 0,4 0,6 0,8 1 Modulation Index m

PCIM 2018, June 5-7, Nuremberg -29- …Do we need Passives?…

I L  kOP CIN  Q  fSW

PCIM 2018, June 5-7, Nuremberg -30- …Do we need Passives?…

Conclusion A. Our dream to use Very Fast Switching Device (VFSD) & eliminate passives is just a dream & it will stay a dream,

PCIM 2018, June 5-7, Nuremberg -31- …Do we need Passives?…

Conclusion A. Our dream to use Very Fast Switching Device (VFSD) & eliminate passives is just a dream & it will stay a dream, B. Using VFSD may open another issues  Inductor is not just an inductor

PCIM 2018, June 5-7, Nuremberg -32- …Do we need Passives?…

 Capacitor is not just a capacitor

PCIM 2018, June 5-7, Nuremberg -33- ...What do we need for future R&D…

PCIM 2018, June 5-7, Nuremberg -34- …Tomorrow…

Major objective of future R&D A. Cost, Cost, Cost, Cost…. B. Size, weight and footprint…. C. Losses… a) Energy saving b) Cooling effort=Size, weight & Cost D. But, Some times reliability and only reliability…. a) Fault tolerance….

PCIM 2018, June 5-7, Nuremberg -35- …Tomorrow…

The Main “Four Elements” of a power converter 1) A Matrix of Power Semiconductor Switches 2) A bunch of Inductors, Transformers and Capacitors (and Resistors ) 3) Control Circuitry 4) Central Control Intelligence

PCIM 2018, June 5-7, Nuremberg -36- …Tomorrow…

1) What is a power semiconductor?  And, what it would be in the future?

PCIM 2018, June 5-7, Nuremberg -37- …Tomorrow…

1) What is a power semiconductor?  From material perspective!  A power semiconductor is just a piece of roasted sand  27.7% of the planet is silicon!!

PCIM 2018, June 5-7, Nuremberg -38- …Tomorrow…

2) What about inductors and transformers?  Very costly and dirty technology!  Limited resources!  Today and it will be even worst tomorrow?

PCIM 2018, June 5-7, Nuremberg -39- …Tomorrow…

3) Control Circuitry is also Si?  Today and will be tomorrow? 4) Central Control Intelligence is just certain number of lines of C code?  When you have it, does not cost anything?  But you need to have it, and it costs ?

PCIM 2018, June 5-7, Nuremberg -40- …Tomorrow…

Passives and Mechanical are dominant factors in the converter cost & size

PCIM 2018, June 5-7, Nuremberg -41- …Tomorrow…

 In future, we MUST use more and more Si, SiC, GaN...  More intelligence…

 Less and Less iron and copper (Passives)  BUT, We cannot eliminated Magnetics & Capacitors

PCIM 2018, June 5-7, Nuremberg -42- … Magnetics …

PCIM 2018, June 5-7, Nuremberg -43- ...Magnetics…

Magnetic materials are progressing slowly 1. Ribbon based material (Amorphous and Nanocristallyn)  High saturation B and relatively low loses  <20kHz  Acoustic noise is a BIG Issue-Still Unsolved 2. Iron-Powder Material  High saturation B but relatively high loses,  Only very low ac B (0.1T)….CCM inductors  <100kHz 3. Ferrites  Low losses, but  Very low sat B<0.45T PCIM 2018, June 5-7, Nuremberg -44- ...Magnetics…

A. What material in range 15kHz to 40kHz, especially at high ac flux density?

PCIM 2018, June 5-7, Nuremberg -45- ...Magnetics…

A. What material in range 15kHz to 40kHz, especially at high ac flux density?  Ribbon based core material (Amorphous and Nanocrystallyne) . Relatively High losses!!!  Ferrite . Low saturation B Big core!!!

 Iron-Powders (Koll Mµ, MPP, High Flux, XFlux, Sendust,….) . High losses!  What Else??

PCIM 2018, June 5-7, Nuremberg -46- ...Magnetics…

A. What is the material in range 15kHz to 30kHz, especially at high ac flux density? B. What about acoustic noise? . <16kHz @ LF bias . Transformers with high leakage inductance, ICTs . Normally, the noise frequency is twice the switching, but only in theory!!

2     B  B   BIAS AC   LF SWITCHING 

PCIM 2018, June 5-7, Nuremberg -47- ...Magnetics…

A. What is the material in range 15kHz to 30kHz, especially at high ac flux density? B. What about acoustic noise? C. What about orthogonal flux & losses?  The flux flow is not well controlled  High leakage inductance transformers and ICTs  Significant additional losses in the lamination!!

 B. Cougo and J. Kolar, “Integration of Leakage Inductance in Tape Wound Core Transformers for Dual Active Bridge Converters”, Proceedings of the International Conference of Integrated Power Electronics Systems (CIPS 2012), Nuremberg, Germany, March 6-8, 2012 PCIM 2018, June 5-7, Nuremberg -48- ...Magnetics…

Prof. Kolar CIPS 2014 PCIM 2018, June 5-7, Nuremberg -49- ...Magnetics…

A. What is the material in range 15kHz to 30kHz, especially at high ac flux density? B. What about acoustic noise? C. What about orthogonal flux & losses? D. What is material in Very High Frequency range?  Key direction for future high level integration  High power density but @ high efficiency  Isolated dc-dc, 170kW/L, extraordinary density!!  The key issue: Magnetics material and the transformer design

PCIM 2018, June 5-7, Nuremberg -50- ...Magnetics…

27.12MHz Converter (MIT & Stanford University) PCIM 2018, June 5-7, Nuremberg -51- ...Magnetics…

Conclusion A. New Core Material is a MUST? . For VHF . But also for MF and HF B. New Material is not enough; New Geometry is also required . The Core  To control of the flux distribution . The Windings  To control of the winding capacitance

PCIM 2018, June 5-7, Nuremberg -52- … Capacitors …

PCIM 2018, June 5-7, Nuremberg -53- ...Power Capacitors…

Also, not progressing well A. Electrolytic Capacitors,  Old Good Boys, Invented in 1920s (Samuel Ruben, William Dubilier……)  We do not like E-Caps because….life time….our perception !!

. >50,000h if the converter is properly designed . Is this really bad as we believe ?

PCIM 2018, June 5-7, Nuremberg -54- ...Power Capacitors…

Also, not progressing well A. Electrolytic Capacitors,  Old Good Boys, Invented in 1920s (Samuel Ruben, William Dubilier……)  We do not like E-Caps because.…life time….our perception !!

. >50,000h if the converter is properly designed . Is this really bad as we believe ?

 In some applications E-Caps are not very desired (PV Inverters)  In some applications E-Caps are Must (Single phase converters)

PCIM 2018, June 5-7, Nuremberg -55- ...Power Capacitors…

Also, not progressing well A. Electrolytic Capacitors, B. Film Capacitors,  Energy density  Current capability [A/µF] is much better than E-Caps, but still not enough

PCIM 2018, June 5-7, Nuremberg -56- ...Power Capacitors…

Also, not progressing well A. Electrolytic Capacitors, B. Film Capacitors, A. MLCC Capacitors (Dielectric X6S, X7T, C0G)  Energy density better than Film Capacitors but not good enough  Good Current Capability  ESR = 1(f)

PCIM 2018, June 5-7, Nuremberg -57- ...Power Capacitors…

Also, not progressing well A. Electrolytic capacitors, B. Film capacitors, A. MLCC capacitors (Dielectric X6S, X7T, C0G)  Energy density better than Film Capacitors but not good enough  Good Current Capability  ESR = 1(f)  C=2 (Uc)

PCIM 2018, June 5-7, Nuremberg -58- ...Power Capacitors…Something New

EPCOS CeraLink™ Capacitors – The revolution for fast switching inverters  Antiferroelectric capacitor technology

1µF 500V

 High Current Capability  High Capacitance at Operating Voltage EPCOS AG 2015 PCIM 2018, June 5-7, Nuremberg -59- ...Power Capacitors…What We Need?

 Very high current capability @ moderate capacitance is required for resonant and switched capacitor converters

I. “Profi” Portable Welding Supply . 500A 40V . 98% Efficiency . 2kW/kg II. “HV”DC Date Center Power Supply . 54V 200A . 98.5% Efficiency Series Resonant Converter (SRC) . 3kW/kg

PCIM 2018, June 5-7, Nuremberg -60- ...Power Capacitors…What We Need?

Partial Power Rated Converter (PPRC)  Very high current capability @ moderate capacitance is required for resonant and switched capacitor converters

I. Energy Storage Interface DC/DC Converter . 15kW (Si Only, No WBG) . 99.5% . 25kW/kg & 50kW/dm3

PCIM 2018, June 5-7, Nuremberg -61- ...Power Capacitors…What We Need?

 Very high current capability @ moderate capacitance is required for resonant and switched capacitor converters I. 20kW SRC: 10-20µF, 450V & 30A RMS (1.5-3 A/µF) II. 100 kW PPR converter: 20-40µF, 450V & 160A RMS (4-8 A/µF)

23uF /100A @100kHz

PCIM 2018, June 5-7, Nuremberg -62- ...Power Capacitors…What We Need?

Conclusions  Very high current capability @ moderate capacitance is required for resonant and switched capacitor converters • up to 10A/µF @ 600V

PCIM 2018, June 5-7, Nuremberg -63- ...Power Capacitors…What We Need?

Conclusions  Very high current capability @ moderate capacitance is required for resonant and switched capacitor converters • up to 10A/µF @ 600V  E-Caps will stay in the game for while, But significantly higher capacitance density, current capability and life time at low frequency are a MUST  Competing with Active Caps, but this is not economical

PCIM 2018, June 5-7, Nuremberg -64- ...Power Capacitors…What We Need?

PCIM 2018, June 5-7, Nuremberg -65- … Gate Drivers & Aux…

PCIM 2018, June 5-7, Nuremberg -66- ...Gate Drivers…

Multi-Cell & Multi-level Conversion will solve all our issues….or may be not…. . 120V OptiMOS for 3 phase 400V system . Very low losses . Very popular and low cost device How many devices we need per a system? I. 2x10=20 per phase and cell II. 2 cells & 3 phases 120 devices per a converter III. Back to back Config. 240 Devices per a system

PCIM 2018, June 5-7, Nuremberg -67- ...Gate Drivers…

I. PULSE WIDTH MODULATOR . Device=1 PWM . 1 Converter =120 PWMs . Traditionally DSC TMS 335/337 . Max 24 PWMs . DSC is not an Option

PCIM 2018, June 5-7, Nuremberg -68- ...Gate Drivers…

I. PULSE WIDTH MODULATOR . Device=1 PWM . 1 Converter =120 PWMs . Traditionally DSC TMS 335/337 . Max 24 PWMs . DSC is not an Option

. Only Option is an FPGA or a CPLD

PCIM 2018, June 5-7, Nuremberg -69- ...Gate Drivers…

II. INTERFACE: CONTROL POWER . FPGA does not like direct connection to power device

PCIM 2018, June 5-7, Nuremberg -70- ...Gate Drivers…

II. INTERFACE: CONTROL POWER . A Link between is a MUST a) Iso.. Gate Driver, b) Iso.. Power Supply Today it is state of the art??

PCIM 2018, June 5-7, Nuremberg -71- ...Gate Drivers…

II. INTERFACE: CONTROL POWER . A Link between is a MUST a) Iso.. Gate Driver, b) Iso.. Power Supply Today it is state of the art??

1 Device 1 GD+PS $$$$

>10% of total BOM cost PCIM 2018, June 5-7, Nuremberg -72- ...Gate Drivers… Today

Tomorrow

PCIM 2018, June 5-7, Nuremberg -73- ...Gate Drivers…

Integrated Gate Driver Circuit & Power Supply . Transfer power and signal using same transmission device . >20MHz carrier . Up to 500mW power . Very challenging, requires very advanced manufacturing capability

PCIM 2018, June 5-7, Nuremberg -74- ...Conclusions…

• Whatever we do, we need Passives • Using VSFD does not mean we will eliminate Passives, we may open new issues • Magnetics • We need Better Core material • We need Better Design • Capacitors • Better Energy Density…E-Caps, MLCC • Much Higher Current Capability • MLCC Better ESR(f) & C(f) • Gate Drivers & Current Sensors • Integration

PCIM 2018, June 5-7, Nuremberg -75- Thank You Very Much for Your Time [email protected]

PCIM 2018, June 5-7, Nuremberg -76-