HIGH POWER RECTIFIER SYSTEMSFor Electrochemical, Electrowinning, Electrorefining,

Electroplating, Special Applications

Quality and Technology In One Package

H I G H P O W E R R E C T I F I E R S Y S T E M S

Rapid provides the best value to meet all of your applicationrequirements. Rapid Power Corporation is the largestindependent manufacturer of High Power Rectifier Systems. We design, manufacture and test integrated high powertransformer – rectifier systems for use in many heavy industrialprocesses such as electrochemical, electrowinning, electrorefining,electroplating and other specialized applications.

Our manufacturing facility is dedicated to the production of transformers: oil immersed, dry open wound VPI (vacuumpressure impregnated varnish) and cast coil epoxy resinencapsulated*), large phase controlled and chopper style rectifier assemblies and fully integrated control systems for all products offered by Rapid throughout the world.

Our multi-pulse rectifier systems of various ANSI configurationsare conservatively designed to provide reliable operation. RapidPower will supply a rectifier to meet your system requirementsand will provide the best value in all applications.

Rapid’s system designs may also be provided with auxiliaryequipment as required by the specification, including switchgear,power factor correction and harmonic filters, heat exchangersand free-standing cooling systems.

* (Manufactured by Dynapower Corporation)

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Utility SupplyUtility Supply

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System Block Diagram for IGBT Chopper Rectifier

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System Block Diagram for Thyristor Rectifier

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Rapid High Power Rectifier Systems consist of the following basic sections:

1 HV Switchgear

2 Rectifier Transformer

3 Thyristor Rectifier

3A Chopper Rectifier

4 Current Measurement

5 DC switch

6 Regulating Controller

7 Operator Interface

8 Harmonic Filter and Power Factor Correction

provides the best value to meet all of your application requirements.RAPID

RAPID POWER CORPORATION

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The choppermodules shown arerated at 1500ADC

and are mounted ina 15,000A, 125VDC

ElectrowinningRectifier system.

System shown is 30,000 ampwith 2x15kA choppers.

RAPID POWER CORPORATION

Introduction

RAPID ENGINEERING

Rapid High Power Rectifier Systems are engineered tointernationally recognized Standards including ANSI, IEEE, IEC,NEMA, UL, CSA, JEC, etc. Rapid Power Corporation applicationand design engineers will work with the client to determine theoptimum rectifier system to meet the specifications. Our designcapabilities include the complete High Power TransformerRectifier System – inclusive of fully integrated operator interfacesand control systems for a single unit or entire multi-unit SCADAnetwork. We can evaluate the impact of the rectifier system onthe incoming power grid and design power factor correction and harmonic filtering as required.

Rapid designs and manufactures thyristor rectifiers and fastswitching IGBT chopper rectifiers for large applications. With the latest techniques in both rectifier technologies, Rapidapplication engineers can recommend the optimum rectifierconfiguration for your project.

Rapid has the experience to deliver the most reliable powerconversion solutions. Rapid has been manufacturing thyristorcontrolled transformer/rectifier systems since the commercializa-tion of the thyristor. Today, Rapid thyristor rectifiers are installedworldwide in many different applications providing high quality,reliable operation.

All Rapid high power rectifier systems are designed, manufact-ured and tested in strict accordance with the latest applicableANSI & IEEE standards.

Dry Type

VACUUM VARNISH PRESSURE IMPREGNATED EPOXY RESIN ENCAPSULATED CAST COIL*

Rapid dry type transformers are designed to be fully integratedwith the rectifier section of the system and may be cooled by forced air, direct water cooling or use of a heat exchangersystem. Multiple transformer systems used to meet ANSIconfigurations have been provided in sizes up to 28 megawattusing dry type transformers.

Features:• Individual transformer ratings to 12,000 kVA• Primary voltages: VPI 23kV, cast coil 34.5 kV• Class H – 220ºC insulation system• Temperature rise 80ºC, 115ºC and 150ºC (VPI only)• Copper windings• Cooling – convection, forced air, direct water

or via a heat exchanger system• Enclosures NEMA 1, 3R and 4• All ANSI circuits available

* Manufactured by Dynapower Corporation. See separate literature for details.

14-megawatt dry type transformer (2 x 7-megawatt) section ratedat 67,000 amp and 425 VDC for a large electrochemical project.

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has the experience to deliver the mostreliable power conversion solutions.RAPID

RAPID POWER CORPORATION

H I G H P O W E R R E C T I F I E R S Y S T E M S

Epoxy vacuum cast coil transformers manufacturedin Vermont, USA. Primary and secondary windingsall cast wound with copper conductors. Electricalconnectors made using tin or silver plated solidcopper bus.

5RAPID POWER CORPORATION

High Power Transformers

Liquid Filled Transformers

Rapid designs and manufactures a majority of its liquid filled rectifiertransformers in house for application in our large industrial rectifiersystems. This in-house capability enables Rapid to fully integrate thedesigns of the rectifier and transformer and take sole source systemresponsibility. The system mechanical integration on the shop floorensures a smooth installation on site. For large kVA and greater than34.5 kV AC input voltage systems, we work with a dedicated supplierto provide completely coordinated system integrations.

Features:• Ratings to 25,000 kVA• Primary voltages to 69 kV• Temperature rise 55ºC or 65ºC• Mineral oil, silicone fluid

and Rtemp• Copper windingsAll ANSI circuits availableConvection cooled, forced air or forced oil (OA, FOA, FOW)

ANSI 45 oil filledtransformer designed

for a 22,500 amp, 275VDC rectifier being

readied for assembly.

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designs and builds its componentsand can deliver them to you quickly.RAPID

RAPID POWER CORPORATION

40,000 amp DC, 220 VDC 12 pulse electrowinning installation with oil-filled transformers and harmonic filter

36,000 amp, 156 VDC chopper rectifier systemcomplete with ANSI 31 dry type transformer

Thyristor & Chopper Rectifiers

These are available in 6, 12, 18 and 24 pulse sets with higherorder combined systems available. Each multi-pulse arrangementis in an ANSI configuration that is selected for the voltage/currentvalues of the application. The multi-pulse criteria is selected toreduce the supply side harmonic content, reduce output ripple,and provide improved regulation. Features of both rectifiertechnologies include:

Features:• Conservative design margins• Copper bus work• Heavy gauge construction• Sub-system integration• High reliability and maintainability• Deep hole drilled copper heat sink

(water-cooled systems)

H I G H P O W E R R E C T I F I E R S Y S T E M S

High Power Rectifiers

7RAPID POWER CORPORATION

Thyristor Rectifier Design

Rapid designs and manufactures the thyristor assemblies used in ourrectifiers. The devices are complete with a rugged RC suppressioncircuit and driven by a dedicated gate driver. The number of deviceassemblies required is a function of the configuration chosen and the total DC current required in meeting the specification.

Direct water cooled thyristor assemblies consist of the semi-conductor mounted on deep hole drilled copper heat sinks.Forced air cooled thyristor assemblies are composed of extrudedaluminum with integrated blower and/or fan assemblies. Largersystems have baffling to ensure proper airflow.

Semiconductor RatingsUp to 3500 A averageUp to 4500 PRV

Temperature sensorsHeat sink over-temperature protection

ClampsSpring-loaded clamps with insulation sleeves

Parallel DevicesCurrent balance is maintained in accordance with ANSI C34.2 standards.

RedundancyN-1 configuration is available.

Device FusesCoordinated high-speed current-limiting fuse with visual indication

Fuse FailureFirst fuse failure will alarm and second failure in same leg results in a fault signal if N-1 redundancy is selected.

22,500 ADC water-cooled thyristor stackin N-1 configuration

Chopper Rectifiers Design

The chopper rectifier designs consist of high frequency switchingtechnology in a modular design package that converts thesecondary AC voltage to a regulated output DC voltage.

Larger power systems are constructed of multiple choppermodules to obtain the specified current requirements. Eachsection of modules has a separate set of sensing and protectionand receives directions from the main chopper controller. Thischopper conversion process has minimal effect on the incomingpower system and a high power factor is maintained at the levelof a fixed diode converter.

The transformer section is configured to optimize the harmonics.The total module count usually results in a 12 pulse configurationas seen by the utility. The load sees a very smooth low ripple DCover the total range due to compact high frequency outputfiltering. Rapid designs and manufactures all the water-cooledIGBT power modules used in our chopper rectifiers.

A full control metering, monitoring, and fast protection scheme is integral to all Rapid chopper rectifiers.

Four channel IGBT choppermodule rated at 1,500 Amps

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has helpful professional service that is available when you need it.RAPID

H I G H P O W E R R E C T I F I E R S Y S T E M S

Semiconductor RatingsIGBTs up to 600 A averageIGBTs up to 2,000 VPRVDiodes up to 600 A averageDiodes up to 2,000 VPRV

DriversDedicated fiber optic gatedriver

Current SensingIndependent IGBT currentsensing

BusworkLaminated copper bus structuredesigned to maintain a low busimpedance and low voltageovershoot

Heat SinksWater-cooled copper for coolingof the isolated modules (fourIGBT and four diodes) maintaininglow junction temperature

Device CoolingModule heat sink plates aredirect contact cooled by meansof circulated water. This waterpath is at ground potential anddoes not require special treating.

Flow ProtectionFlow detectors.

Temperature SensorsHeat sink over-temperatureprotection.

Number of ModulesConservative design marginswith multiple parallel modulesper section.

Parallel DevicesSymmetrical assemblies withcurrent balance controlled ±5%.

RedundancyN-1 power moduleconfiguration is supplied.

Device FusesEach IGBT has a coordinatedhigh speed current-limiting fuse with visual indication ofthe activated fuse.

Fuse FailureFirst IGBT fuse failure will alarmand failure of second will resultin automatic current reduction or a trip signal being generated.

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High Power Chopper Rectifiers

RAPID POWER CORPORATION

Additional Features for the Chopper:• High power factor over full range• Low output ripple• Low harmonic distortion• Dynamic response• Modular construction

The above is a section of a 36,000 amp choppersystem used on a graphite furnace application.

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systems are assembled with pride anduse only the highest quality components.RAPID

RAPID POWER CORPORATION

Rectifier Controls

Rapid Power designs and manufactures the rectifier controlsystems for use in our high power rectifier systems. The integrationof this control with commercially available Programmable LogicControllers (PLC) and Personal Computers (PC) is used to producea wide range of power rectifier system designs capable of analogor digital control via a variety of serial protocols. The communicat-ion network and operator interface may be designed to meet yoursystem control and monitoring requirements.

Operator Terminal(Magelis, Panel View, etc.)

Analog Controlpanel with recorders

Personal Computer-driven touch screencontrol running HMIsoftware

Basic digitalcontroller and

HMI panel

Basic Control andTrigger Board plus

driver circuit foranalog system

SectionControl1,2,3,4

Chopper MainController

ModuleCurrentSensing

Local&

RemoteControl

DigitalInterface

B C DA

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FieldContacts

MainPLC

Laptop computer

Modem

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CHOPPER MODULE

FiberOptic

Drivers

To Additional Rectifiers

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Remote

To Additional Rectifiers

DC BUSVOLTS

DCSHUNT

OperatorPanel

Isolators

Control&

FieldContacts DCS

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DriverBoard

Analog Signals

DiscreteSignals

DC BUSVOLTS

DCSHUNT

Control And TriggerBoard

Chopper Rectifier Control Block Diagram

Thyristor Analog Control Block Diagram

H I G H P O W E R R E C T I F I E R S Y S T E M S

Cooling Systems

Rapid rectifier systems may be designed to be cooled by a variety of cooling methods. These include forced air, direct water, or combination of closed loop heatexchanger systems integral to the cabinet, or freestanding, for installation external to the rectifier.

Liquid Cooled

The cooling water is taken from the cooling cubiclethrough a manifold supply tube to the base section of therectifier to feed several parallel cooling circuits. The jointsin the water circuit are designed to prevent corrosion and includes pressure tested seals. The heat sinks for the liquid-cooled semiconductors are deep hole drilledcopper and cooled by means of de-ionized water whichflows in a closed loop through the power circuit. Thewater flows in a counter-current pattern to obtain eventemperature distribution. Thermostatic proportioningvalves are used to minimize plant cooling water volumebased on the operating power when closed loop water to water heat exchangers are selected.

Sealed Air To Liquid Cooled

When portions of the rectifier systemcannot be cooled with direct water andusing external forced air is not an option,they may be cooled using a sealed air towater heat exchanger. Rapid has extensiveexperience with cooling sealed dry typepower rectifier systems using this method.

Forced Air Cooled

Forced air cooled rectifier unitsincorporate finned aluminum heat sinksand may be operated continuously at fullrated current at an intake air temperatureof up to 40ºC with custom higher ambienttemperature designs available.

High Power Controls and Cooling Systems

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Air to water heatexchange in a sealeddry-type transformerapplication. Rectifier iscooled using a closedloop de-ionized water to water heat exchanger,while the ambient anddry-type transformersare cooled by the air towater heat exchanger.

Water to water heat exchanger

16,500 amp air-cooled thyristor rectifier

Liquid to air heat exchanger.

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Hv Switchgear

Rapid manufactures high power rectifier systems up to 69 kV and integrates commercially available medium and high voltagecomponents into the systems. Rapid coordinates the ACswitchgear for complete system integration and safety.

DC Disconnect Switch

Rapid has extensive experience integrating commerciallyavailable DC disconnect switches into our systems as required.

Current Measurement

Rapid rectifiers use precision current shunts for the controlregulation and for the current measurement of our high powersystems. Commercially available current measurement systemsfor outer loop monitoring can be incorporated in accordancewith the specifications of the project.

DC Buswork

Rapid uses electrically pure copper bus work exclusively in ourrectifier systems. Bus work with plated bolted joints and flexibleconnections are designed to minimize bus losses and to matchthe clients’ application requirements.

30,000 amp precision shunt

RAPID POWER CORPORATION

High current DC Switch

High voltage fuseddisconnect switch

will help you define your rectifierrequirements quickly and efficiently.RAPID

H I G H P O W E R R E C T I F I E R S Y S T E M S

Applicable Codes and Standards

Rapid designs, manufactures and tests our power rectifiers and transformers in accordance with the prevailing specifications and the following codes and standards.

ANSI StandardsC34.2-1968 Practices and requirements for semiconductor power rectifiersC57-12.00 & 12.10 Standards for liquid and dry transformersC57-18.10 Standard for rectifier transformers

IEC StandardsIEC 76 Power transformersIEC 146 Semiconductor convertersIEC 147 Essential ratings and characteristics of semiconductor devices and

general principles of measuring methodsIEC 148 Letter symbols for semiconductor devices

IEEE Recommended StandardsIEEE 519 - 1992 IEEE recommended practices and requirements for harmonic

control in electrical power systems

NEMA StandardsNEMA R1 Safety code for semiconductor rectifiersNEMA R16 Electrochemical processing semiconductor rectifier requirements

NFPA Standards70 National Electric Code

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High Power Support Equipment

RAPID POWER CORPORATION

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provides the best value to meet all of your application requirements.RAPID

RAPID POWER CORPORATION

Factory Testing

Rapid has an established high current test facility for the testing of high power transformer/rectifier systems. A complete line up oftransformers and rectifiers are tested at rated current and ratedvoltage with total power levels dictated by our test area capacity.

Field Testing

Rapid Field Service Engineers have extensive experience travelingworldwide to field test, commission and start up major high powerrectifier systems. Rapid recommends that large systems have aload capacity large enough to fully test the system parameters. If this is not available, Rapid engineers can usually develop a‘substitute load’ that will test the equipment to a satisfactory level.Our field service technicians and system engineers are available atyour request for start-ups, preventative maintenance, emergencyservice and hands-on training with new equipment.

Core and coil being tested prior to final assembly

Field testing a high power rectifier with substitute load

H I G H P O W E R R E C T I F I E R S Y S T E M S

Training

Rapid Service Engineers may instruct our customers’ operatorand maintenance personnel during the commissioning/start of the unit or during final test at our Corporate Headquarters.This can be operational training and/or fullmaintenance-repair training for shift personnel.

Spare Parts

Rapid maintains a multi million dollar spare parts inventory and has the appropriate factoryapproved spare parts on hand and ready for youruse to assure maximum up-time of your process.Rapid’s power supplies are designed for decadesof trouble-free use when the installation androutine maintenance guidelines contained in the service manual are followed.

Documentation

Rapid engineering develops a completedocumentation package for each major systemmanufactured. A full set of electrical andmechanical drawings enable the client to maintainand service the system. Project documents include thedescription of the system, control, software and cut sheets of key components.

Quality Control

Each piece of equipment we build is rigorously tested and put through a systematic quality control examination prior toshipment. Our test facilities utilize state of the art equipment to verify that the power supply you receive is exactly what youordered. Our staff of highly competent test technicians performsa full range of operational and functional testing, and maintainscomplete documentation of all test procedures and results. Priorto shipment, a final quality control inspection is performed.

Sales Engineering

Our Sales Department is staffed by professional sales engineersand can help you select the appropriate piece of equipment foryour specific application. From the simplest rectifier to a fullyintegrated rectifier-transformer system with harmonic filter andpower factor correction, Rapid’s experienced sales staff can helpyou define your specific requirements, and then provide you withthe solution to your power conversion needs. Contact the Rapidcorporate office or your regional office or representative for yourpower rectifier system requirements.

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High Power Testing and Training

Spare parts