Airak, Inc.Paul Grems Duncan9058 Euclid Avenue

Manassas, Virginia 20110-5308voice: (703) 330-4961fax: (703) 330-4879pduncan@airak.com

An Optically Isolated HV-IGBT Based Mega-Watt Cascade Inverter Building

Block for DER ApplicationsU.S. Department of Energy SBIR Grant

DE-FG02-01ER83142August 27, 2001 – February 26, 2001

Project Goals

! Primary: Develop a new full-bridge, three phase, megawatt inverter topology based upon HV-IGBTs with optical current, voltage, and temperature sensing in addition to command/control interfacing.

! Secondary: Compare/contrast advantages of optical sensor and control methodologies over conventional methodologies (e.g. safety, reliability, costs, response, efficiency, phase margin, dynamic range, etc.).

Team Members

PowerElectronicsSubsystem

Design- Dr. Jason Lai

Optical Sensorand System

Design- Paul Duncan

TechnicalManagement- Stan Atcitty

AdministrativeManagement

&Funding

- Dr. Imre Gyuk

Motivation

! Optical Sensor Technologies + High Power Systems => Tremendous Advantages

! Commercial Point of View: “Dual Use” for both Power Electronics and Utility Power Industries (i.e. Potential Markets are Large)

System Configuration

Load

Lfa

ider

iLis

vas

S1ava

vb

Vd1

S2a

S3a

S4a

vbs vcs Transformer

vCvS

Lfb S1b Vd2

S2b

S3b

S4b

Lfc S1ca vcVd3

S2c

S3c

S4c

DER sources

Cascaded inverter

Sensor & Control Configuration

SensorConditioning

iacvdc

Fiber Optic SensorsHV-IGBTs

Interface Circuit

DSP Circuit

DERSource

Gate Drivers

S1a

S2a

S3a

S4a

Optical fiber links

Complete Module for Cascaded Inverter

vacidc

Why HV-IGBTs?

! Compared to GTO or other thyristor-based devices…– Eliminate Current Snubbers and Voltage

Clamps– Simplify Gate Drive Circuitry and Isolation– Provide Cost Advantage at System Level– Increased Efficiency and Reliability

Implementation

IGBT Module Test Setup

Lo2mH

Vdc

E2

G2 DUT

C2 E1

C1

G1

Cdc

10:1 Homemade CT with small toroidferrite coreµ=2600

Pearson 411 CT1A:0.1V

To Scope1A:0.01V

Busbar

High freq.cap. 4.7uF

Bushing– small

copper tube

PulseGenerator

InductiveLoad

2mF0 ~ 650V

HV-IGBT Turn-on and Turn-off Waveforms Voltage, Current and Switching Energy at 360 kW

VCE (200V/div)

Eon = 120 mJ

Time (0.2us/div)Time (0.2us/div)

IC (200A/div)

Eoff = 100 mJ

(a) Turn on (b) Turn off

100 mJ

Current overshootdue to diode reverse recovery

Voltage overshoot due to Llk(di/dt)

120 mJ

IC (200A/div) VCE (200V/div)

IGBT Test Structure

Pulse Tester

IGBTLiquid Cooled Heat Sink

Bode Plots of the Control Loop Transfer Function

65°P.M.

Ki/VPWMHi(s) Gid(s)

0 dB line

8 kHz control bandwidth

Little phase shift at 60 Hz

Simulated Voltage and CurrentWaveformsVdc

vab

van

ia

0

50ms40ms30ms20ms10ms0sTime

Frequency Spectra of Phase A Current

Har. Freq Ia Ia ∠ Ia# (Hz) (A) (%) (°)

1 60 127.6 100% 1.05 300 0.07 0.05% -97.97 420 0.07 0.05% -99.711 660 0.08 0.05% -98.113 780 0.06 0.04% -124.617 1020 0.06 0.00% -104.219 1140 0.07 0.00% -106.2

0.0

0.2

0.4

0.6

0.8

1.0

60 300

420

660 780

1020

1140

Frequency (Hz)

Phas

e A

Cur

rent

(pu)

THD = 0.14%

PWM

MC

3315

3

12V+

-

FLT

+15V

-5V

+15V

+15V

-5V

-5V

5

4

6

78

1

23

DC

/DC

DC

/DC

Optical Fiber

IGBT Module

! Optical Fiber Link Used! High Current Output Stage: >5A! Desaturation Protection! Low Component Count

Ron

Roff

Opto-Isolated Gate Driver Topology

HV-IGBTs & Gate Drivers! During the 2nd Phase

of this program intend to move toward Therma-ChargeTM heat pipe assemblies.

Therma-ChargeTM technology allows the rejection of multiple kilowatts of heat from power semiconductors directly to ambient air. This is an important conclusion considering the potential alternative is a liquid pumped loop system that has inherent long-term reliability (leaks), maintenance (pump failure, fluid cleanliness, filtering) and corresponding cost issues.

Why Optical Sensors?

! Intrinsic Safety! Intrinsic Isolation! Increased Reliability! Higher Response! Greater Dynamic Range! Small Size and Weight

Fundamentals:Sensing with Crystals

Photodetector #1

Photodetector #2

SensorMaterial

PolarizedLaser Source

E or H

AppliedMagnetic or Voltage Field

φ

PolarizationBeamsplitter

Fundamentals:Conversion to Current Measurements

The holy grail: I = total current flowing through a conductor

H=magnetic field intensity

∫ •=l

dlHir

B = magnetic flux density &µµµµ = permeability

µBHr

r=

(a constant)

VlB φ=

(a constant)

φφφφ=polarization rotation

Sensor and Power Conditioning Function

Optical Sensors&

OptoElectronics

IBM CompatibleRack Mount Chassis

TMS320C6701 EVM&

AED-106 A/D

CodeComposer

Studio

AED-106 A/D andPWM Interface

PCB

FPGAFoundation

To/From Gate Drivers

Optical Configuration (Voltage or Current Sensor)

1310 Laser

1550 Laser

X

X

FusionSplices

p/o Front Panel

FC Connectors (2)FC-FCBulkheadAdapters (2)

SMOF SMOF

Sensor

FC-FC InlineAdapter

FCConnectors

(4)

FC-FC InlineAdapter

SMOF FiberSpool

Lo-BiFiber Spool

Lo-Bi SMOF

FC Connector

SMOFMMOF

MMOF

ST Connectors (2)

Coupler

MiniaturePolarizing

Beamsplitter

PINPhotodiodes

Optical Sensor Analog Conditioning

Analog Interface Connector toAED-106 Samtec FTSH-125-01-L-MT (to/from AED-106-J14)

BufferScaling

AmplifierTransZ

Amplfier #2TransZ

Amplfier #1

DC RestorationAmplfier

Anti-Aliasing Filter

1v pp maximum

MitelSemiconductorMF432 STPhotodiode

C

AED-106 input channelcontains a series resistor of4.32kOhms. Set low-frequency pole IAW C=1/(27143*fp)

(Optional)

Optical Current Sensor Sectional

Fundamentals:Bragg Grating Temperature Sensor

///////

fiberoptic

coupler

widebandopticalsource

fiberBragggrating

fiber

refractive index variationλ − λλ − λλ − λλ − λB

λλλλλλλλB

Spectrometer

Bragg Temperature Sensor DataBragg Temperature Sensor

S/N: H0022014

y = 0.067x + 730.42R2 = 0.9944

730731732733734735736737738739

0 20 40 60 80 100 120

Temperature [deg C]

Wav

elen

gth

[nm

]

Pending Milestones! Power Electronics Subsystem Integration (Dec ‘01)! Optical Subsystem Integration (Dec ’01)! Systems Integration (Jan ’02)! Systems Testing/Comparative Analysis (Jan/Feb ’02)! U.S. DoE Demonstration (Feb/Mar ’02)! U.S. DoE Follow-on Proposal (Mar ’02)

! U.S. DoE 3-Phase System Development (Jun ’02+)

Next Steps

! Demonstration of MW-Level HV-IGBT and Optical Technologies for Industry Partners

! Joint Collaboration and Development of Technologies for Specific Power Electronics and Utility-Scale Applications

Q&A / Discussion

For Further Information Contact:

Paul Grems Duncan9058 Euclid Avenue

Manassas, VA 20110-5308Voice: 703-330-4961pduncan@airak.com