Current Interests

Prof. Mahima Gupta

Mahima Gupta

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EMI Eradicator frequency spectrum and circuit diagram

EMI Eradicator

  • Challenge: High EMI noise due to WBG devices.
  • Innovation: EMI eradication at the device level -> Reduced EMI noise accompanied with higher efficiency.
  • In numbers: ~8% efficiency improvement and ~20dB noise reduction (750W prototype)
iso-MCC overview diagram

iso-MMC

  • Challenge: Line-frequency transformer supply chain and DC short circuit fault tolerance issues in conventional MMCs.
  • Innovation: An isolated universal building block module design for a family of modular power converters.
  • In numbers: Transformer size reduction by ~30-50x
Zero-Common-Mode Inverter - diagram and prototype

Zero-Common-Mode Inverter

  • Challenge: Common-mode noise issues in 2-level converters.
  • Innovation: A 2-level inverter topology with zero common-mode current flow due to non-switching common-mode voltage
  • In numbers: 2kW prototype record up-to 45dB lower conducted noise and 10x lower ground RMS currents
Integrated Power Module for MMC - diagram and prototype

All Integrated Power Module for MMC

  • Challenge: Bulky electrolytic capacitors in modular converters.
  • Innovation: Three-phase integration at the module level à Capacitor is sized to filter out switching frequency only
  • In numbers: ~1μF capacitor per-phase per-module vs. ~50μF (1kW prototype)
Prof. Lei Zhou

Lei Zhou

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Magnetically Levitated Precision Positioning Systems

  • EM and control design for nano-precision positioning in IC manufacturing equipment
  • Breaking trade-off between bandwidth and acceleration capability in motion stages
Prototype magnetically levitated precision positioning system

Bearingless Motors Design and Control

  • Bearingless motors for heart pumps and reaction wheels
  • Self-sensing control for bearingless motors
Two different bearingless machine prototypes

Enhancing Self-Sensing Control for Electric Machines

  • Enhancing robustness of speed self-sensing estimation and control for electric machines
Mini dynamometer for self-sensing control validation

Over-actuated Ring Motors for Drones/eVTOL

  • Actively use normal force generation in motors to control mechanical vibration
  • Remove large mechanical bearing in rim-driven propellers
  • Aims for higher thrust/weight ratio in heavy-lifting drones and eVTOL aircrafts
Over-actuated axial flux PM machine protoype
Prof. Jinia Roy

Jinia Roy

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Solid State Marx Generator diagram

Pulsed Power: Solid State Marx generator

  • Mitigate the inrush current,
  • Control the voltage balance between stages,
  • Minimize stage capacitance, and
  • Generate a controlled long flat-top pulse
MMC with active decoupling

Photovoltaic inverter and Modular multi-level converter

  • Higher power density, lower cost
  • Enhanced fault tolerance
  • Higher reliability
  • Better controllability
Basic schematic of gate driver for multiple series connected devices

Gate driver for series connected devices for direct Switch pulsed power supplies

  • Immunity to EMI
  • Enhanced reliability
  • Short-circuit failure detection
  • Optimized layout for high power high voltage operation
Rendering of prototype

Power management in Space Applications

  • Modularity -> Redundancy, interleaving, mass, efficiency
  • Partial Power Processing -> Efficiency, mass
  • Active Capacitor Circuit -> Mass
  • WBG Devices -> Radiation hardened
  • System level design optimization
Prof. Daniel Costinett

Daniel Costinett

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Converter Design and Optimization

  • Framework for holistic schematic-level optimization
  • Fast, broad, unified analysis of power converters
Graphic illustrating system-level optimization

EV Power Electronics

  • Wired and wireless chargers, APM, motor drive, BMS
  • Low power to 100s of kW+
  • Functional integration of multiple converters/drives
  • Battery charging, balancing, and monitoring

Integrated Power Conversion

  • Monolithic high-current battery chargers
  • Intelligent gate driving
  • High-current POL supplies

High-Performance Power Supplies

  • Wired and wireless chargers, APM, motor drive, BMS
  • Low power to 100s of kW+
  • Functional integration of multiple converters/drives
  • Battery charging, balancing, and monitoring
Prof. Daniel Ludois

Daniel Ludois

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Electrostatic machine prototype rendering

Electrostatic Machines & Drives

  • No magnetism
  • Machines without copper, steel, or magnets
  • Holding torque without heat
  • Compact MV drives
Wireless power transfer vehicle demo

Wireless Power Transfer & Radio

  • ISM band 6.78 MHz power electronics
  • Up to 2 kW
  • Wireless power transfer applications
  • HF Band radio applications (replacing linear amps)
Integrated filters - prototype

Integrated Inductors & Capacitors

  • Collocated electric magnetic fields
  • Laminations become capacitor plates
  • Lamination insulation become capacitor dielectric.
  • Example use is dv/dt filter in a bus bar, 5x smaller
Transformerless isolated DAB diagram

Transformerless Isolated Dual Active Bridges

  • 4-quad blocking GaN switches
  • High frequency capacitive isolation
  • Suitable for emerging bidirectional switching devices
  • No AC magnetics
Prof. Bulent Sarlioglu

Bulent Sarlioglu

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Electric machine design renderings

Electric Machine Design

  • Flux-switching PM Machines
  • Surface PM and internal PM Machines
  • Axial Flux Machines
  • Novel topologies with reduced rare earth materials
CSI diagram

Wide-bandgap Device based Power Electronics

  • VSI, CSI, DC/DC, Active Rectifiers. Also developing capability for solid state circuit breakers (SSCBs)
  • Gate drive design and optimization of PCB boards for minimization of parasitic inductances
  • Current Source Inverters using WBD devices, reduce EMI, bearing currents, motor voltage ringing, create fault tolerance to dc bus short circuits
Diagram and prototype - in-slot cooling

Thermal Design of Electric Machines

  • Direct in-slot cooling of electric machines
  • Novel electric machine cooling with 3D heat exchangers
  • Novel two-phase liquid and vapor cooling of electric machines

Integrated Motor Drives

  • Integrated motor, power electronics, and control as one unit
  • Joint cooling of the machine and the power electronic converter
  • Multiple phases and multiple inverters for fault tolerance capability
50kW IMD prototype machine
Prof. Giri Venkataramanan

Giri Venkataramanan

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AC/AC power flow control

  • Devices to control power flow in fixed frequency ac systems
  • No dc link or frequency conversion
  • Lower cost with equivalent performance to full conversion
AC/AC power flow illustration

Stability of power electronics – grid interfaces

  • Use Power/Frequency small signal transfer functions to evaluate stability
  • Capable of studying point of interconnection as well as system level stability
  • Apply traditional notions of stability margin
  • Applicable to legacy and hybrid systems
Bode plots

Wide Band Gap circuit layout techniques

  • Apply microwave circuit layout tools to power converter geometries
  • Realize ~nH interconnection inductances
  • High-speed switching with no overshoots or ringing – 100V/ns @20A
Oscilloscope trace of WBG switching device

Isolated matrix converters

  • Back-to-back matrix converter topology
  • Apply high frequency isolation
  • Integrated frequency and voltage conversion
  • Suitable for emerging bidirectional switching devices
Isolated matrix converter diagram