UNITROL® 5000Excitation Systems for Medium and LargeSynchronous Machines

Copyright © 2000 Photodisc, Inc. 275 371

UNITROL® 5000 System Overview

Page 2

The UNITROL 5000 is the most powerful product in the ABB SwitzerlandUNITROL® series of excitation systems. The microprocessor-based voltageregulator uses the latest available technology. The development is basedon more than 40 years experience with semiconductor voltage regulatorsand more than 15 years experience with microprocessor technology forthis application.

Application areas• Static Excitation Systems (SES) for

50 Hz, 60 Hz or 16 2/3 Hz power supplywith field currents from 1000 ADC tomore than 10,000 ADC

• Automatic Voltage Regulating Systems(AVR) for exciter machines with specialfunctions, supply frequencies from16 2/3 Hz to 400 Hz.

Regulator highlightsAdditional regulator redundancy• Dual-channel system with backup

current regulator

Digital input processing

• Three-phase voltage measurement• Three-phase current measurement• Digital processing of the input values

with a signal processor

Additional functions

• Software solutions only – withoutadditional hardware

Additional inputs and outputs

• Easy to extend to the required numberwith ARCnet® devices

• Digital and analog

Event and error log

• With real-time stamp• Remote interrogation possible.

Power section highlightsPower converter redundancy

• Up to a maximum of eight parallelpower converters are possible

• Power converter redundancy is com-pletely independent of the regulatorconfiguration

Intelligent power converterelectronics

• Active equalization of the currentbetween the power converters

• 4-quadrant operation (negativeexcitation current is possible)

• Thyristor current monitoring• Fan control and monitoring• Monitoring of fuses, power converter

temperature and cooling-air flow• Bridge current display.

Communication with thesystem• The most frequently used protocols

for higher level control systems aresupported

• A second control panel in the controlroom is possible, up to a maximumdistance of several 100 m

• Remote diagnostics by an ABB serviceoffice is available via Internet usingthe PC software “AVRview”.

Fig. 1:The UNITROL 5000 hasa modular structure ofthe function units

Voltageregulator

AC fieldbreaker

Power converterunits

Field flashing,Crowbar

275 535

ABB

UNITROL® 5000 System Configuration

Page 3

The UNITROL 5000 is designed as a modular “building-block system”. Morethan 80 % of all systems can be made from type-tested system components.This guarantees higher quality and makes shorter delivery times possible.The power section consists of one or more thyristor power converters, fieldbreaker on the AC or DC side, the field flashing circuit and the solid statede-excitation system with Crowbar.

Fig 2: The standard configurations of the voltage regulatorsection and power converter units can be combined atwill, e.g. S5T, D5E, A5S, Q5T

Less wiring thanks to the internalARCnet® field busThe exchange of data within the system,e.g. between the voltage regulator, powercomponents and interface devices takesplace via the serial ARCnet bus.

Additional interfaces or control panels canbe located and operated up to a distanceof several 1000 m via an optical link.

Powerful and reliable powerconvertersEither compact power converters of theDCS 500 series or type UNL 13300 orVerithyr power converters are used forthe UNITROL 5000. The type and thenumber of parallel power converters arebased on the required field current, theceiling voltage and the maximum duty-cycle required by the customer.

The following options are available:

• Natural or forced cooling• Redundant fans• Possibility to do maintenance work

on one power converter during theoperation of the system (with 5-poleisolator).

Equal distribution of the currentbetween several powerconvertersFor the first time for parallel power con-verters, a new ABB development offersregulated distribution of the total cur-rent between the active units. This canprevent the overloading of individualthyristor branches due to unsymmetricalcurrent flows and significantly reduces theprobability of a failure of the individualpower converters (see Fig. 3 on page 5).

AVR

AVR

AVR1

AVR2

BFCR

AVR1

BFCR

AVR2

BFCR

S 5 _

D 5 _

A 5 _

Q 5 _

_ _ E

_ _ T

_ _ S

AVR: Voltage regulator (AUTO) with field currentregulator (MAN)

BFCR: Backup-field current regulator

High availability due to the additionalbackup current regulatorTo further increase the availability of the excitationsystem, in addition to the voltage regulator (AUTO)and the excitation current regulator (MAN), anindependent current regulator (separate devicewith power supply, measurement and gate controlcircuits) can be used. Because of the follow-upcontrol for all the inactive regulators, in the case offailure of the active regulator a smooth switch-overto a ready-to-operate regulator channel is guaran-teed.

ABB

UNITROL® 5000 Software Functionality

The well-structured software of the standard program already offers most ofthe regulation, protection and monitoring functions required for the secureoperation of the excitation system and comprehensive event and datalogging for diagnostics and service.

Page 4

Functionality of the standardprogramThis comprises the following excitationspecific functions:

Regulator functions

• Voltage regulator with PID filter(AUTO operating mode)

• Field current regulator with PI filter(MAN operating mode)

• Reactive load and/or active loaddroop/compensation

• Limiters for:– maximum and minimum field current– maximum stator current (lead / lag)– P/Q underexcitation– Volts-per-Hertz characteristic

• Follow-up control– CHANNEL 1 ↔ CHANNEL 2 (for

dual automatic channel systems)– active CHANNEL ↔ BACKUP

(for systems with backup regulator)– operating mode AUTO ↔ MAN

• Power factor / reactive load regulation• MANUAL restrict• Power system stabilizer (option)

– conventional in accordance withIEEE - PSS2A

– Adaptive power system stabilizer– Multiband power system stabilizer.

Protection and monitoring functions

• Field flashing time• Overcurrent protection

(instantaneous / inverse time)• Volts-per-Hertz protection• Loss of excitation protection• Power converter temperature• Rotor temperature• Rotating diodes monitoring• Thyristor conduction monitoring• Power converter fuses monitoring• Power converter fans monitoring• Measuring circuit supervision.

Monitoring and protection functions areclassified in three different action levels:

• Fault display only• Switch-over to the second channel or

to the backup regulator (if provided)or use of the available power con-verter redundancy

• Instantaneous excitation trip for pro-tection purposes.

Control functions

All standard excitation sequences andinterlocks are software-based with fixedpre-programmed function blocks.

They can be extended with freely pro-grammable function blocks by the user.

Data recordingThe UNITROL 5000 software has anevent recorder (fault logger), that canrecord up to 100 events and alarms withreal-time stamp. The logs are read andanalyzed with the control panel or theCMT software.

Up to six measurement signals can berecorded in real-time with the datarecorder (data logger). These can bedisplayed graphically in the CMT soft-ware trend window for diagnostic pur-poses.

Monitoring of the processorSelf check

After the power supply is switched on,the processor starts a self-check. Theprocessor also monitors the variouspower supply voltages.

Program execution monitoring

The processor card has an internalwatchdog function, which monitors thecorrect execution of the program.

ABB

UNITROL® 5000 Additional Software Functions

Page 5

Application function blocksIn addition to the standard softwarefunctions, further universally applicablefunction blocks of various kinds areavailable for the application program.These are tested application proceduressuch as input/output extensions, specificmonitoring functions, etc.

Power System Stabilizer (PSS)The purpose of the power system stabi-lizer is to improve the stability of thegenerator and the transmission systemas a whole by using the excitation todamp load oscillations. The PSS operatesby influencing the input of the voltageregulator – extremely effective withstatic excitation systems, but also effectivefor systems with rotating exciter.

ABB offers three different types ofpower system stabilizer:

PSS in accordance with IEEE

For the stabilizer in accordance withIEEE - PSS2A, fixed parameters take careof optimum damping with adjustablelead/lag filters. To determine theseparameters ABB has calculation softwarethat takes account of the generator andexcitation system data, as well as thetransformer and network reactances.

Adaptive power system stabilizer (APSS)

The adaptive power system stabilizerworks with variable parameters that areset by continuous calculation of theworking point and the current state ofthe power system. For the UNITROL 5000no additional hardware is necessary –contrary to the UNITROL P system.

Multiband power system stabilizer(MBPSS)

Instead of a single lead/lag filter theMBPSS has three individually adjustableworking bands, in order to ensure effec-tive working over the complete frequencyrange of typically 0.05 … 4.0 Hz. Thethree bands are designed to damp theelectromechanical oscillations at low,medium and high frequencies.

Rotating diodes monitoringWith this addition, short circuits or opencircuits in the branches of a rotatingrectifier that is used in brushless systemsare detected over a wide range of rota-tional speeds.

A software monitoring function calculatesthe harmonics of the excitation machinefrequency from the excitation currentsignal. Depending on the amplitude inrelation to the excitation current, it ispossible to distinguish between a shortcircuit and an open circuit in the branch. Fig. 3:

Current equalizationbetween severalUNITROL 5000 powerconverters

The characteristics of the excitation system can be adapted by bothextending the application program and with optional softwarefunctions, in order to optimally match the system to the customer’srequirements.

+–

RST

1 2 n

Σ

}

t

Σ

}

t

Σ

}

t

Thyristor firing pulses from AVR

Current equalizing line

ABB

Page 6

UNITROL® 5000 System Communications

Communication with the systemThe service panel SPA is connected tothe system via an RS485 interface. Thefour-line display shows system functions,system parameters, measured values,alarms etc. in clear text form. The excita-tion system can be controlled with thepush-buttons.

The control panel LCP (optional forsmaller excitation systems) can be usedfor local or remote control is connectedvia the ARCnet bus. The LCP is for thecontrol of the system, the display ofactual values and events.

Optical link for commissioningand serviceThe UNITROL 5000 system can be con-nected to a PC with the CMT softwareinstalled via an optical link. This ensuresa fast and secure communication withthe excitation system.

Fig. 4:Communication levelsfor the user friendlycontrol and monitoringof the UNITROL 5000system

Integration in higher hierarchicalcontrol systemsCommunication with higher hierarchicalcontrol systems is possible with theappropriate bus coupler that is connectedto the DDCS interface (via an opticallink).

The following standard protocols aresupported for control and data transfer:

• MODBUS• MODBUS+• Profibus.

Today, simple and user-friendly commissioning and operation are asimportant as the easy integration in higher hierarchical control systems.UNITROL 5000 offers several types of human machine interfaces, andalso various bus couplers for higher hierarchical control systems.

DD

CS

AR

Cne

tE

ther

net

RS4

85

CIN CIN. . .

LANTCP/IP

#

#

Modbus, Modbus+,

Profibus etc.

LAN

ENTER

ACT PAR COMSELFUNC

REM

RESET R E FLOC

0I

UNITROL R

CH2

Nxx

x

Internet

Firewall

Fire

wal

l

SPA

LCP

LCP

Exc

itat

ion

syst

emP

ow

er p

lant

Rem

ote

Dia

gno

stic

s

CIN: Power converter electronics

I/Ointernal

Digital/analoginputs/outputs

Voltageregulator

ABB

Remote diagnosticsIf the excitation system is equippedwith the optional remote diagnosticsfunction, ABB service personnel can,with the customer’s permission, accessthe system via the internet.

For further details, please refer to thelast page of this brochure.

AVRview

The same software tools that were used for the UNITROL F system are usedfor the UNITROL 5000 system. These are the GAD tool and the CMT tool. Bothhave proved themselves as outstanding software tools for these applications.

Software Tools for Commissioning and Maintenance

Fig. 5:Display of signal trendswith CMT

Fig. 6 (below):Display of applicationprograms andparameter values withCMT

Engineering software GAD“Graphical Application Designer” (GAD)is a PC software tool for applicationprogramming. The tool has the follow-ing characteristics:

• Application programming for extend-ing the standard functions

• Graphic editor to create and modifythe program documentation

• User defined layout of the documents

• Possibility to create new documenta-tion symbols.

The application programs created withthe GAD software are loaded in theregulator module with the CMT.

Commissioning andMaintenance Tool (CMT)With this software, modifications aremade to the application program, thesystem functions are monitored andparameter values are changed. Theprogram has a screen display, withwhich the system can be controlled andthe status monitored. It has the follow-ing functions:

Trending display

• With this window (Fig. 5), up to sixanalog signals can be shown in real-time environment (“Trending”)

• All the signals available in the systemare selectable for this display

• User friendly menu for selecting thesignals, including all parameters forscaling and offsets.

Application program display

• Display of the application program(Fig. 6), created with the GAD soft-ware

• Display of actual values of selectedpoints in this display.

Page 7

Parameter and signal display window

• Display and changing of parametersor signals in table form

• Each parameter or signal can be as-signed to a parameter or signal groupthat can then be selected and processedas a group.

Other display windows

• Event log display, shows the last 100events and alarms in chronologicalorder (“Faults”)

• Display of the data recorded (“DLog”),six channels, each with up to 1000data points).

ABB

3B H

T 49

0 30

0 R

0201

Prin

ted

in S

witz

erla

nd (0

306-

PD

F)

We reserve the right to change in the interest of technical development.

For more information aboutUNITROL please visit our website

www.abb.com / unitrol

ABB Switzerland LtdStatic Excitation Systems, Voltage Regulatorsand Synchronizing EquipmentCH-5300 Turgi / SwitzerlandTelephone: +41 (0) 58 589 24 86Fax: +41 (0) 58 589 23 33Email: pes@ch.abb.comInternet: www.abb.com / unitrol

AVRview – Remote diagnostics for UNITROL® 5000

If a problem occurs with your UNITROL 5000 excitation system, youcan obtain help quickly and economically with remote diagnostics.The possibilities of remote troubleshooting and rectification offaults saves travel and accommodation costs.

In order to use the remote diagnosticsoption, the customer needs to plug in anadditional board (CAP) for each voltageregulator channel. An RJ45 socket isused for connection, via an Ethernetcable, with the local network (LAN) orvia an Ethernet Router and a modemwith the telephone network. A directconnection between CAP and PC viaEthernet cable is also possible.

Not only all important signals and para-meters values, but also the data and eventloggers are available for data exchange. Comfortable AVRview

“AVRview” is the user interface for remotediagnosticss for Microsoft™ Windows® 2000 andsupports the following functions:

• Display of operating status• Display of signals and parameters• Changing of parameters• Download and display of

Event Logger entries• (Automatic) download and editing of

the Data Logger contents• Setting of the real-time clock and

Data Logger functions.

AVRview makes remote diagnostics assimple as on-site service. Support ofcustomers in case of system disturbances,problem analysis, fault rectification andoptimization can be carried out via theInternet – it makes no difference wherethe UNITROL 5000 is located!

Combination of hardware and software

Fig. 7: The status display provides the most important informationon the operating status of the excitation system

Fig. 8: In the “selection window” (above), any signals can beselected for a general overview; the “data loggerwindow” represents stored signals graphically