Power Electronic Converters for Advanced Electric … Electronic Converters for Advanced Electric Power Systems Dushan Boroyevich The Bradley Department of Electrical and Computer

Power Electronic Converters for Power Electronic Converters for Advanced Electric Power Systems Advanced Electric Power Systems

Dushan Boroyevich

The Bradley Department of Electrical and Computer EngineeringVirginia Tech, Blacksburg, VA 24061-0111, USA

Tel.: 540.231.4381, Fax: 540.231.6390, Email: [email protected]

Center for Power Electronics Systems

The DOE Workshop on Systems Driven Approach to Inverter R&D

Maritime Institute, Baltimore, MDApril 23-24, 2003

Workshop on Systems Driven Approach to Inverter R&D

April 24, 2003 Power Electronic Converters for AEPS DB-2

Outline

• Introduction

• Source and grid interface issues

• Modular converter design issues

• Standard-cell, open-architecture, electric power conversion systems



Center for Power Electronics SystemsA National Science Foundation Engineering Research Center

Industry Consortium with 75 Partners

Virginia Tech

Universityof Wisconsin

Madison

RensselaerPolytechnic

Institute

Universityof Puerto Rico

Mayaguez

NorthCarolina A&T State

University

Virginia Tech

SystemIntegration

IPEM



Power Electronics Building Block (PEBB)and Advanced Electric Power Systems

Gen.

Gen.

DC Distribution

Active Filter

SMES

PropulsionAC/AC Motor

AC/ACEMALS

DC/ACAC/DC

MV AC Distribution

SMESPCS

Active Filter

LV ACDistribution

ASD ASD

AESS

• Most (all) sources and loads interfaced through power electronics converters:• High system controllability, flexibility, and responsiveness• Increased availability• Reduced size and weight• Increased efficiency



Commercial General PurposeInduction Motor Drives?• 3-phase, 0-300 Hz, 0-480 V• 0.2-200 kW (overload 110-150%, surge 150-200%)• Cost: 200-400 $/kW• Size: 0.3-0.6 kW/lit (5-10 W/in3)• Weight: 0.6-1.2 kW/kg (0.7-1.4 lb/HP)• Communications: large variety available • Reliability: 10,000-30,000 hrs MTBF? • Required modifications:

– Front-End + DC Link ⇒ Source Interface Converter– AC Filter + AC Voltage Sensing– Control



Power Electronics Converters forDistributed (Renewable) Generation

DG(Renewable)

Source orStorage

GridInterfaceConverter(Inverter)

SourceInterfaceConverter

InverterControllerSource Controller



Standard Commercial Gen-Sets

Engine Gen.

Gas TankLoad

Constant, Low Speed High Zo

Analog Controller

Governor Control Field Control

VA

VB

VC

VG

GridInterfaceConverter(Inverter)

SourceInterfaceConverter

InverterControllerSource Controller

☺ Almost unlimited ampere-hour capability

Low speed, bulky, high cost engine/generator Poor transient response High voltage distortion with unbalanced and/or nonlinear load

☺ Almost unlimited ampere-hour capability

Low speed, bulky, high cost engine/generator Poor transient response High voltage distortion with unbalanced and/or nonlinear load



Unbalanced/Nonlinear Loads

Vaiaibic

S1

S6S4S2

S5S3

Vg

+

Vc

Vb

VA

VG

VB

VC

RR

2R2R RR

00 30 60 90 120 150 180

VCVBVA

Unbalanced loads

Vaiaibic

S1

S6S4S2

S5S3

Vg

+

Vc

Vb

VA

VG

VB

VC

Nonlinear loads

Sfn

Sfp

Vf

Ln

4-Leg Three-Phase Inverter• New space vector modulation• New control algorithms• High bandwidth required



Gen-Set with Power Electronics InterfaceLoadGas

Tank

ADSP 21062 Sharc DSP Controller with Altera FLEX 10K EPLD

Eng. Gen.

Governor Control

Va

Vb

Vc

V G

MainInverter

150 kW, 5 kHz

Analog Field Controller

LoadConditioner30 kW, 20 kHz

Source InterfaceConverter

Grid Interface Converter

• Suitable for any variable unidirectional ac source:• Micro-turbines• Wind power• Micro hydro power



Simulation

Unbalanced loads Nonlinear loads

Load Current Load

Current

Main Inverter Current

Load conditioner CurrentLoad

conditioner Current

Main Inverter Current

Output Voltage Va

THD = 4.2%VABC



ExperimentTest Condition:

Vo = 277 V, fo = 60 Hz, Vdc = 815 V Power Stage

Hardware Setup

va

vb

vc

100 kWBalanced Resistive

Load

va

vb

vc

idc-link0 - 20 - 20 kW

Unbalanced Resistive

Load

va

ia

20 kW Resistive+

20 kW Rectifier3Φ Balanced Load



Switching Noise of Inverter System

LVdc/2

Vdc/2

C

LoadDM

• Differential-Mode Noise: reduced by LC-filter

Vn

ground path

parasiticcapacitor

parasiticinductor

CM

• Common-Mode Noise: its effect depends on parasitic values



Active Common-Mode Noise Elimination

4-leg inverter for unbalanced/nonlinear loads

LoadV1V2

V3V4

Vdc/2

Vdc/2

Va

Vc

VnCn4-leg inverter with

common-mode noise reductionVn250V/div 25V/div

Balanced load

250V/div 50V/divUnbalanced

load

250V/div 25V/divNonlinear

load



Soft-Switched Phase-Leg PEBB Module• Increase switching frequency and reduce switching noise• Increased power density and increased system bandwidth

Laminated Bus

Optic Fibers

AuxiliaryIGBT ModuleCM150DY-24H(1200V/150A)

Sensor Board

Current Sensor

Voltage Sensor

Resonant Tank

DC BusConnection

Main IGBT ModuleCM300DY-24H (1200V/300A)

Gate Drive Boards

Zero-Voltage, Zero-CurrentTransition (ZVZCT)Soft-Switching Cell

• Main switch zero current turn off• Main diode zero current turn off• Auxiliary switch soft switching



ZVZCTPEBB

Modular, PEBB-Based Converters

Specifications• AC Voltage: 3Ø, 60 Hz, 480 V• DC Voltage: 800 V• Power Rating: 100 kW• Switching Freqy: 20 kHz

100 kW ZVZCT Three-PhaseInverter / Rectifier



Power Conditioning System for SMES

250 kW, 1800 V, 20 kHz

Bi-directional Chopper Three-Phase Inverter

N

P

0Utility

SMESCoil I P

• Suitable for any variable dc source:• Batteries• Solar (PV) cells• Fuel cells

• With back-to-back inverter, suitable for• Flywheel storage

• Energy reserve• Voltage support• VAr compensation• Harmonic filtering



2uH

2uH0.25uF2000V

0.25uF2000V

300uH

+

+

+

+

2 x CM150DY 4 x CM400HA4 x 800uF, 450V

S1

S2

S3

S4

D1

D2

2 x RM400HA

Sx1

Sx2

Sx3

Sx4

High-Density, High-Bandwidth Prototype

• Zero-Voltage, Zero-Current Soft-Transition

• Water cooled • Optical fiber interface• Integrated driver

• High power density: 47 W/in3

1200 V3Φ ac

±1750 Vdc

P = 250 kW, fsw = 20 kHz, fcl = 3 kHz

• Laminated bus



Modular “Plug & Play” Control Architecture

FloatingPower

Supplies

OpticalIsolation

GateDrive Snubber

OpticalIsolation

GateDrive Snubber

PWMGenerator

Fault & ErrorLogic

CommunicationControl

Current & TemperatureMeasurement

Serial Communications Link & Control Power Supply

+

_

AC

T

A

V

Integrated Phase-Leg + Hardware Manager

ZVZCT 3Φ VSI

ZVZCT 3Φ three-level VSI

UniversalController

(Application Manager)

SmartPhase-Leg

PEBBs(Hardware Managers)

125 Mb/s POF Daisy-Chained Serial Bus (PESNet)



Specifications• AC voltage: 208 V• DC voltage: 400 V• Power rating: 20 kW / unit• Switching freqy: 32 kHz

DC bus

PEBB unit

PEBB unit

Modular Converter Systems

iZ

• Example: Parallel Converters

• Zero-sequence current must be controlled in (N) parallel converters• For modularity, need independent controllers per converter• New control algorithm provides for zero-sequence current control by:

• Small modification in modulation• Simple additional (zero-sequence) current controller in N-1 converters



Simulation

Three-Phase Boost Rectifier OperationIa1

Ia2

5A/divIa1 Ia2

5A/div

ACCurrents

I01

I02

5A/div

I01 I02

5A/div

DCCurrents

w/o Zero-sequence control w/ Zero-sequence control



Experiment

Three-Phase Boost Rectifier Operation

w/o Zero-sequence control w/ Zero-sequence control

5 A /d ivI a 1

I a 2

5 A /d iv

I a 1

I a 2

ACCurrents

5 A /d ivI 0 1

I 0 2

5 A /d iv

I 0 1

I 0 2

DCCurrents



ConceptualReference Model

Energy Processing

Devicessemiconductors, magnetic cores,

dielectrics, heat spreaders, …

Packaged Componentstransistors, inductors, capacitors,

heat sinks, …

Integrated Modulesfor energy flow control and

energy storage

Power Converters

Power Stationparallel, series, or cascade converters

with switchgear and enclosure

Power Distribution

Generation and Transmission

1

2

3

4

5

6

7

ISO / OSI Telecom Model

Physical

Link

Network

Transport

Session

Presentation

Application

Electric Power Conversion

Device

Component

Module

Converter

Station

Network

Transport

Modeling and Simulation

Finite Element

Physics-Based Lumped Parameter

Behavioral

Average

Application

Power Flow

Cost and Quality

Control

Physical(Universal Controller, HM)

Real-TimeOperating System

Elementary Control Objects

Data Flow

Application

Enterprise

Mission

Physical(Universal Controller, HM)

Integrated Modulesfor energy flow control and

energy storage

Power Converters

Power Stationparallel, series, or cascade converters

with switchgear and enclosure

Real-TimeOperating System

Elementary Control Objects

Data Flow

Devicessemiconductors, magnetic cores,

dielectrics, heat spreaders, …

Packaged Componentstransistors, inductors, capacitors,

heat sinks, …

Finite Element

Physics-Based Lumped Parameter

Behavioral

Average

Application

Standard-Cell, Open-Architecture, Electric Power Conversion Systems

Documents

Power Electronic Converters for Advanced Electric … Electronic Converters for Advanced Electric Power Systems Dushan Boroyevich The Bradley Department of Electrical and Computer