Highly Dynamic, Precise and Flexible Current Source for ... · Highly Dynamic, Precise and Flexible...
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Highly Dynamic, Precise and Flexible Current Source for Plasma Research and Accelerators
Georgios Tsolaridis and Jürgen BielaProject Nr: 25197.1 PFEN-I
Outline
• Introduction
• Proposed Topology
• Full System Simulations
• Future Work
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Introduction– Applications
• Application areas:− Driving of septum/bumper magnets− Medical applications (e.g. MRI)− Arc/Plasma investigation for next
generation HVDC circuit breakers
• Specifications for HVDC breakers:− Emulation of fault currents in DC grids Arbitrary current source
− 30 kA output current @ 10 kV− > 200 A/μs current gradient− Up to 10 ms pulse length
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• Output voltage ±10 kV• Pulsed current 30 kA• DC current 20 kA• Current gradient > 200 A/µs • Pulse length 10 ms• Current ripple < 0.1% • Possible loads R, L & arc• Waveform Arbitrary• High Repeatability• High Modularity
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Introduction – Full System Specifications
Introduction - Target System Specifications
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Single Stack Source
Output voltage ±10 kV
Output current 1.5 kA
Current gradient >10 A/μs
Current ripple <1 %
DC current 1 kA
Full Scale Source
Output voltage ±10 kV
Output current 30 kA
Current gradient >200 A/μs
Current ripple <0.1 %
DC current 20 kA
• System concept− Current-shaping converter
• Interleaved, high fs, 2-level, low-voltage− Step voltage source
• Modular Multi-Level Marx-Type Converter
Proposed Topology - Operation Principle
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Proposed Topology – Current Shaping Converter
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• Multi-phase buck-type current shaping converter– Output current: 0 .. 1.5 kA– Output voltage: 0 .. 550 V– Interleaving Current ripple reduction
– High switching frequencySiC MOSFET
Proposed Topology – Marx Type Modular Multilevel Converter
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• Modular Multilevel Marx Converter M3TC– Staircase voltage– H-bridge → Bipolar
voltage ±10kV– Low switching frequency
→ slow dynamics– High capacitance value
needed• Film capacitors
selected (reliability)• Smaller energy
density larger volume
Hybrid Multiphase Controller*
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*G. Tsolaridis and J. Biela “Adaptive Hybrid Control Concept for Multiphase DC-DC Converters”, IEEE ECCE, Cincinnati, Ohio, USA 2017
• Transients Adaptive hysteresis controller
• Steady State PI controller
+ Phase shifting control Interleaving (low ripple)
• Benefits: Time-optimal transient response Excellent disturbance rejection Design simplicity Good steady state performance Very low current ripple
Simulation Results : Arbitrary waveform generation (RL load: 1 Ω – 10 μH)
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Slow ramp/Sinusoidal 200Hz• PI mode enabled• Min. ripple during the
transient
Pulse transient• Hysteretic mode• Max. achievable current
gradient
Simulation Results: Inductive Load – Preliminary Results
• Assumptions− 100 µH load inductance− < 3 kV max. output voltage
• Load inductor Low ripple• Operation could be optimized for
well-defined loads• Preliminary results
− Dynamics depend on # of stages
− Ripple/overshoot could be optimized
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Arc measurement by High Voltage Laboratory/ETH Zurich
Challenge: Dynamic Behavior of Load (Arcs)
• Arcs Extreme load fluctuations• Chaotic waveform of arc voltage• High frequency oscillations Highly dynamic control required
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Simulation Results: Performance under highly fluctuating load*
• Arc-Load:− Behavioral arc model− Measurement-based model− Stochastic changes
− > 250 V/µs− > 400% change in R-value
• Resulting current− Load current: ± 10%
*G. Tsolaridis and J. Biela “Modular, Highly Dynamic and Ultra-Low Ripple, Arbitrary Current Source for Plasma Research”, IEEE PPC, Brighton, UK 2017
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Arc measurement by High Voltage Laboratory/ETH Zurich
Future Work
• List of publications:
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3. G. Tsolaridis and J. Biela “Modular, Highly Dynamic and Ultra-Low Ripple, Arbitrary Current Source for Plasma Research”, IEEE PPC, Brighton, UK 2017
2. G. Tsolaridis and J. Biela “Adaptive Hybrid Control Concept for Multiphase DC-DC Converters”, IEEE ECCE, Cincinnati, Ohio, USA 2017
1. G. Tsolaridis and J. Biela “Hybrid Control Concept for Highly Dynamic Buck Converter Systems”, IEEE EPE, Warsaw, Poland 2017
• Development of the prototype system• Validation of the dynamic control system• Data synchronization/exchange• Advanced charging concept• Optimization of
• Dynamic behavior• Robust control• Repeatability
Prototype of previous concept
Thank you for your attention