IEEE PresentationPower Rectifiers

8/21/2019 IEEE PresentationPower Rectifiers

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AC to DC Power Conversion Now and in the Futu re

PCIC-2001-14

Tony Siebert Anders Troedson Stephan Ebner Member, IEEE Member, IEEE Member, IEEE

ABB Automation, Inc ABB Automation, Inc ABB Industrie AG

P.O. Box 372P.O. Box 372 CH- 5300 Turgi

Milwaukee, WI 53201 Milwaukee, WI 53201 Switzerland

USA USA


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Agenda

• Introduction

• System Design Factors

• Technology Assessment

–

• Technology Comparison

• Innovative Information Technology (IT) support• Conclusions


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Rectifier History

1913 Fist Mercury-Arc rectifier

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

1925 Mercury-Arc rectifier for grid control

1939 First 50 kV HVDC transmission

1950 Development of Contact Rectifier

1947 Invention of Transistor

1902 Invention of Semiconductor Diode (Crystal type)

Mercury Arc Rectifier Contact Rectifier


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Rectifier History

1958 First semicond. Diode rectifier

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

1960 First diode plant > 100 kA

1968 First thyristor rectifier 1970 First diode rectifier unit > 100 kA

Introduction of Thyristor Technology

Introduction of Diode Technology

Thyristor Rectifier Diode Rectifier


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Rectifier History

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

1990 First thyristor rectifier for DC-Arc Furnace

1985 First thyristor rectifier for Aluminium Smelter

Ongoing Development of Diode Rectifier Technology

Ongoing Development of Thyristor Rectifier Technology

3” Thyristor Rectifier 4” Thyristor Rectifier 2” Thyristor Rectifier


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Rectifier History

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

Mid-1990’s first Chopper rectifier in Eletrolysis

Introduction of GTO TechnologyIntroduction of IGBT Technology

Introduction of IGCT Technology

IGBT Chopper Module PowerPac3IGCT Chopper Module


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System design and decision factors

AC-Network Design Parameter Ä Voltage level / voltage variation

Ä Frequency / frequency variationÄ Available short circuit capability

Ä Allowed power factor

Ä Allowed harmonic distortion

DC-Process Design Parameter Ä Voltage / current operating range

Ä Voltage / current rippleÄ Voltage / current regulation accuracy

Ä Voltage / current regulation speed

Ä Overload capabilities

Further Decision FactorsÄ System reliability

Ä System efficiencyÄ Reparability and diagnostics

Ä Footprint and mechanical dimension

Ä Investment- / install- / life-cycle cost

Ä Production load schedule criteriaÄ Energy day-time tariffs criteria

Ä Plant start-up / lay-off criteria


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Process Ratings

Rectifier Application Current (Amps) Voltage (DC)

Chemical electrolysis 5,000 - 150,000 40 - 1,000 Volts

Aluminum potline 10,000 - 300,000 < 1,300 Volts

DC Arc Furnace 50,000 - 130,000 600 - 1,150 Volts

Graphitizing Furnaces 20,000 - 120,000 50 - 250 Volts

Zinc/Lead, etc electrolysis 5,000 - 100,000 100 - 1,000 Volts

Copper refining 10,000 - 50,000 40 - 350 Volts

Traction substations 1,000 - 5,000 500 - 1,500 VoltsLV AC Drive (DC bus) 0 - 10,000 250 - 1,000 Volts

MV Drive (DC bus) 0 - 5,000 3,400 - 6,000 Volts

Typical Rectifier Rating


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Technology Assessment

• Diode

• Thyristor

• Diode and DC/DC Converter

(Chopper)

• Active Rectifier


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Diode Rectifier Topology

Double wye connection with interphase transformer

LOAD

6 puls circuit

3 - phase bridge connection

LOAD

6 puls circuit

Di d S t R l ti P i i l


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Diode System Regulation Principle

Step of current setpoint

Step of OLTC

current without saturable reactor ramp control ( load impedance related )

current with saturable reactor ramp control

Range of saturable reactor control

T *) typ. 3 .. 5 s depending on OLTC drive

(saturable reactor control up to 5 ms depending on the load)

t [seconds]

Idc[kA]

T *)

Di d R tifi


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Diode Rectifiers

• Simplest Technology

• Longest use

• Used with On-Load-Tap-Changers

• Used with saturable core reactors

(amplistats, voltage controlled reactors)

2 4 - P u l s e D i o d e R e c t i f i e r

+ 7 . 5 °

- 7 . 5 °

L o a d

Th i t R tifi T l


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Thyristor Rectifier Topology

Double wye connection with interphase transformer

LOAD

6 puls circuit


LOAD

6 puls circuit

Th i t S t R l ti P i i l


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Thyristor System Regulation Principle


theor.current without phase angle ramp control () ( load impedance related )

current with phase angle ramp control in operation

Range of phase angle control

T *) typ. 100 ms .. 300 ms

possible up to 5 ms depending on the load

T *) t [milliseconds]

Idc[kA]

Steps only with OLTC

Th ristor Rectifiers


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Thyristor Rectifiers

• Simple Technology

• Widely Used

• Can be used with On-Load-Tap-

Changers• Relatively fast control of current

2 4 - P u l s e T h y r i s t o r R e c t i f i e r

+ 7 . 5 °

- 7 . 5 °

L o a d

Diode Rectifier + DC Chopper Topology


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Diode Rectifier + DC-Chopper Topology


LOAD

6 puls circuit

DC Chopper Regulation Principle


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DC-Chopper Regulation Principle


theor.current without PWM ramp control ( load impedance related )

current with PWM ramp control

Range of modulation control

T 1) typ. 100 ms .. 300 ms with electrolyis process load

possible up to 1 .. 5 ms depending on the load

t [milliseconds]

Idc[kA]

T 1)

Tmod 2) typ. 0.2 ms .. 1 ms

Tmod2)

Ton Toff

Diode Rectifier with Chopper Converter


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Diode Rectifier with Chopper Converter

• Newer Technology

• Relatively entering into Market

• Merging of older (diode) and new

technology• Fast control of current

+7.5°

-7.5°

Active Rectifier Topology (AC Chopper)


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Active Rectifier Topology (AC-Chopper)


LOAD

6 puls circuit

Active Current Source Inverter

AC Chopper Regulation Principle


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AC-Chopper Regulation Principle

T 1) typ. 100 ms .. 300 ms with electrolyis process load

possible up to 1 .. 5 ms depending on the load


theor.current without ramp control ( load impedance related )

current with ramp control

Range of modulation control

t [milliseconds]

Idc[kA]

T 1)

Tmod 2) typ. 0.2 ms .. 1 ms

Tmod2)

Ton Toff

Active Rectifier (AC-Chopper)


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Active Rectifier (AC-Chopper)

• Newest Application of Technology

• Limited Market entry

• Based upon proven technology• Fast control of current

Active Current Source Inverter

Load

Technology use by Process


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Technology use by Process

Application Diode Thyristor Chopper Active Rectifier Chemical Electrolysis Seldom Standard Seldom Future

Aluminum Potline Standard Seldom Not Acceptable Distant Future

DC Arc Furnace Not Acceptable Standard Seldom Future

Graphitizing Furnace Standard Seldom Future FutureZinc Electrolysis Standard Seldom Future Future

Copper Refining Seldom Standard Seldom Future

Traction Substation Standard Seldom Future Distant Future

LV AC Drive (DC Link) Standard Seldom Not Applicable SeldomMV Drive (DC Link) Standard Seldom Not Applicable Seldom

Technology Share


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Technology Share of Units > 10 kA

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1 9 7 2

1 9 7 4

1 9 7 6

1 9 7 8

1 9 8 0

1 9 8 2

1 9 8 4

1 9 8 6

1 9 8 8

1 9 9 0

1 9 9 2

1 9 9 4

1 9 9 6

1 9 9 8

2 0 0 0

Chopper

Thyristor

Diode

Technology Share

Technology Comparison


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Technology Comparison

• Power Factor

• Efficiency

• Harmonic Distortion

• Reliability / Availability / Service Support

• Space Requirements• System Cost

The Process Load Characteristic


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The Process Load Characteristic

U d o

I d

Aluminium

Zinc

Chlorine

Copper

I Range

U Range

100 %

100 %

50 %

25 %

75 %

Power Factor Comparison


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Power Factor vs Transformer Impedance

0.8800

0.8900

0.9000

0.91000.9200

0.9300

0.9400

0.9500

0.9600

6 7 8 9 10 11 12

Transformer Impedance

P o w e r

F a c t o r

Diode / DB

Thyristor / DB

Note: Low Transformer Impedance = High Voltage

Harmonics



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0.40

0.45

0.50

0.55

0.60

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1.00

250.00 300.00 350.00 400.00 450.00Ud [V]

P F

[ - ]

Diode OLTC Thyristor OLTC Thyristor Uncompensated Thyristor Compensated

Diode vs Thyristor with Electrolysis Process Load

Ud

Id



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• Diode Good

• Thyristor Low

• Diode and Chopper Good

• Active Rectifier Best

Efficiency vs. Voltage


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y g

0.9

0.91

0.92

0.93

0.94

0.95

0.96

0.97

0.980.99

1

0 200 400 600 800 1000 1200 1400 1600Voltage

E

f f i c i e n c y

Typ Dio/Thy Bridge Typ Dio/Thy Single Way

Typ Chopper Dio/Thy Projects

Comparison at Nominal load Operation


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p p

Nominal Load Operation DC-Voltage: 500 V

DC-Current: 70 kA

DC-Power: 35 MW

Diode

System

Thyristor

System

Chopper

System

AC-Power (12p-Transformer) 39 MVA 41 MVA 38 MVA

Power Factor without correction 0.91 0.86 0.93

Compensation up to PF=0.93 3 MVAR 8 MVAR -Compensation up to PF=0.98 10 MVAR 15 MVAR 7 MVAR

Losses

Transformer (including harmonics) 430 kW 450 kW 400 kW

Rectifier 183 kW 192 kW 170 kW

Chopper 250 kWLine Filter (for PF=0.93) 56 kW 84 kW

Total 669 kW 726 kW 820 kW

Relative Difference -151 kW -94 kW 0 kW

Efficiency (for Components considered) 0.981 0.980 0.977

Comparison at Reduced load Operation


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p p

Reduced Load Operation DC-Voltage: 440 V

DC-Current: 50 kA

DC-Power: 22 MW

Diode

System

Thyristor

System

Chopper

System

AC-Power (12p-Transformer) 25 MVA 34 MVA 24 MVA

Power Factor without correction 0.90 0.65 0.93

Compensation up to PF=0.93 3 MVAR 8 MVAR -Compensation up to PF=0.98 10 MVAR 15 MVAR 7 MVAR

Losses

Transformer (including harmonics) 240 kW 260 kW 170 kW

Rectifier 105 kW 120 kW 100 kW

Chopper 250 kWLine Filter (for PF=0.93) 56 kW 84 kW

Total 401 kW 464 kW 520 kW

Relative Difference -119 kW -56 kW

Efficiency (for Components considered) 0.982 0.979 0.977

Efficiency Comparison


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y p

• Diode High

• Thyristor Medium - High

• Diode and Chopper Low

• Active Rectifier Medium - Low

Harmonic Comparison


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p

15

711

1317

1923 25

2931

3537

4143

47

0o

20o

40o

6 0 o

0

2

4

6

8

10

12

14

16

AC Current in [kA]

Harmonic Number

2 0 k A , 20 0 V DC , 6 P u l s e R e c t i f i e r

D i o d e a n d C h o p p e r ( 0 d e g r e e s ) a n d T h y r i s t o r d e p e n d i n g o n o u t p u t D C v o l t a g e )

0o

10o

20o

30o

40o

50o

60o

Harmonic Comparison


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• Diode Good

• Thyristor Lower

• Diode and Chopper Good

• Active Rectifier Best

Reliability Comparison


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Based Upon Component Count ofRectifier Devices

• Diode High

• Thyristor High

• Diode and Chopper Low• Active Rectifier Medium

Service Skill Comparison


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• Diode Low

• Thyristor Medium

• Diode and Chopper High

• Active Rectifier High

System Cost Comparison


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Diode Rectifier 105%

Thyristor Rectifier 100%

Diode & Chopper 124%

Active Rectifier 115%

Based upon past projects, component count and further

developments.

Space Comparison


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• Diode Average

• Thyristor Larger

– (with power factor included)• Diode and Chopper Larger

• Active Rectifier Average

Conclusions


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Considerations

• Total System Requirements• Future Provision of System

Requirements

• Customer’s Experience / Background

• Technology comparison for exact

project

– All Technologies Will continue for near

future


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- Thank You -

Documents

IEEE PresentationPower Rectifiers