Optimal Design of Inductive Components Based on Accurate Loss

160 Pages·2012·13.22 MB·English

Optimal Design of Inductive Components Based on
Accurate Loss and Thermal Models
Jonas Mühlethaler and Johann W. Kolar
Power Electronic Systems Laboratory, ETH Zurich
Introduction
System Layer
Component Layer Material Layer
www.ferroxcube.com
Mittwoch, 15. Februar 2012 D-ITET/PES Jonas Mühlethaler 2
Introduction
Application of Inductive Components (1) : Buck Converter
(DC Current + HF Ripple)
Schematic Current / Flux Waveform
Modeling Difficulties Solutions
- Non-sinusoidal current / flux - FFT of current waveform for the
waveform calculation of winding losses
- Current / flux is DC biased - Determine core loss energy for each
segment and for each corner point in the
piecewise-linear flux waveform
- Loss Map enables to consider a DC bias
Mittwoch, 15. Februar 2012 D-ITET/PES Jonas Mühlethaler 3
Introduction
Application of Inductive Components (2) : Inductor of DAB Converter
(Non-Sinusoidal AC Current)
Schematic Current / Flux Waveform
Modeling Difficulties Solutions
- Non-sinusoidal current / flux - FFT of current waveform for the
waveform calculation of winding losses
- Core losses occur in the interval of - Improved core loss equation that
constant flux considers relaxation effects
Mittwoch, 15. Februar 2012 D-ITET/PES Jonas Mühlethaler 4
Introduction
Application of Inductive Components (3) : Three-Phase PFC
(Sinusoidal Current + HF Ripple)
Schematic Current / Flux Waveform
Modeling Difficulties Solutions
- Non-sinusoidal current / flux - FFT of current waveform for the
waveform calculation of winding losses
- Major loop and many (DC biased) - Determine core loss energy for each
minor loops segment and for each corner point in the
piecewise-linear flux waveform (-> minor
loop losses)
- Add major loop losses
Mittwoch, 15. Februar 2012 D-ITET/PES Jonas Mühlethaler 5
Introduction
Overview About Different Flux Waveforms
Sinusoidal
DC Current +
HF Ripple
Non-Sinusoidal AC
Current
Minor Loop
Sinusoidal Current
+ HF Ripple
Major Loop
Mittwoch, 15. Februar 2012 D-ITET/PES Jonas Mühlethaler 6
Introduction
System Layer
Component Layer Material Layer
www.ferroxcube.com
Mittwoch, 15. Februar 2012 D-ITET/PES Jonas Mühlethaler 7
Introduction
Overview About Other Modeling Issues
Flux Density
Heat Dissipation
Distribution
Air Gap
Stray Field
Core Type
Current
Distribution
Winding Type /
Arrangement
Mittwoch, 15. Februar 2012 D-ITET/PES Jonas Mühlethaler 8
Introduction
Wide Range of Realization Options
Inductors / Transformers Core Shapes
www.ferroxcube.com
Conductor Shapes
www.wagnergrimm.ch, www.ferroxcube.com
www.pack-feindraehte.de, www.jiricek.de
Mittwoch, 15. Februar 2012 D-ITET/PES Jonas Mühlethaler 9
Introduction
Modeling Inductive Components (1)
Procedure
1) A reluctance model is introduced to describe the
electric / magnetic interface, i.e. L = f(i).
2) Core losses are calculated.
Reluctance Model
3) Winding losses are calculated.
4) Inductor temperature is calculated.
Mittwoch, 15. Februar 2012 D-ITET/PES Jonas Mühlethaler 10