electrical tests

8/20/2019 Electrical Tests

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200/210 MW Turbogenerator

TESTS OF GENERATOR PROTECTIONS AND SYNCHRONISING.

1.0 After the generator dryout is declared completed, short circuit tests on thegenerator with short circuits at different locations of the bus are carriedout. uring these tests the operation and stability of the protecti!e relaysare chec"ed. #roper planning and prior arrangement with the appropriateagencies at site is called for to carry$out the tests se%uentially andcontinuously so that minimum time is ta"en to complete the tests and thusminimi&ing the period of no$load running of the T' set.

2.1 (n the unit loc" out relay )* +, the outgoing wires are remo!ed for pre!enting operation of )*' and )* 'T during testing i.e. tripping of

boiler and turbine-.

2.2 nsure that the operation of )* + would trip only the field brea"er.

2. otor arth ault$

This protection is recommended to be tested and "ept operati!e prior tothe commencement of the generator dryout itself.

3y e4tending the a.c. au4iliary supply to ( and (( rotor / relays theoperation of these relays are chec"ed by ma"ing a temporary short of the

positi!e pole of the generator field to ground. Test with 205 field !oltagehas been found to suffice.

.0 16.76 85 9 phase short$

a- $phase short circuit made location 1 in the enclosed s"etch- after the16.76 85 line side :T;s, for the generator dryout is retained. :lose thefield brea"er and slowly increase the e4citation.

uring the tests, currents are measured in the following relays.

)7' $ 'en. iff. elay.)7'T $ 'en. Tr.iff. relay.21 $ 3ac" up impedance relay.


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uring this test the following are chec"ed$i- The pic"up of the o!erall diff. elay )7'T-@ bac" up impedance

relay 21'-

ii- >on$operation of 'en. iff. elay )7'- pro!ing its stability for

e4ternal faults !en upto *0 rated stator current-.

b- $phase short circuit shifted to a location before the 11 85 line side:T;s location in the enclosed s"etch- closoe the field brea"er and slowly increase the e4citation.

:hec" operation of 'en. iff. elay )7'-. All the three flags shouldappear.

Measurement differential current in the neutral side :T;s and

!oltage across relay terminals when the relay pic"s up.

c- :hec"ing of inter turn fault relay *

eutral grounding trasformer to be put in ser!ice. Cn the 16.76 85 sideground phase to create stator ground fault. :lose field brea"er. As soonas this is done chec" that the stator / relay has operated.

*.0 'enerator open circuit test

8eep all protections tested earlier in ser!ice. (nclude 'enerator #.T. in the16.76 85 bus for measurement of !oltage.

'enerator transformer, +nit Au4. Transformer to remain isolated from thegenerator by "eeping open the lin"s.


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:lose the field brea"er and gradually increase the 4citation.

*.1 ecord the measurement in the proforma enclosed. Cn reaching the ratedgenerator !oltage.

*.2 Measure and record the !oltage across the stator earth fault relayterminals *


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:lose the field brea"er and gradually increase the e4citation.

:hec" the non$operation of +AT diff. relay pro!ing its stability for e4ternalfaults. 4citation raised to get about *0 o the rated currents on the =T?ide of the +AT transformer-.

Measure the :T secondary current in o!er current relays mounted on*.*85 ?witchyard if pro!ided-.

).0


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10.0


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8eep the Master eul Trip MT- out of circuit. 3B manually operating therelay contacts of )7' trip the unit$

a- Cbser!e that loc" out relays )*', )*T and )*+ operates withrespecti!e annunciations.

b- Cbser!e operation of field brea"er trip 220 85 brea"er trip, and theturbine trip. eset all the relays and bring bac" turbine to ratedspeed. Arrange for synchroni&ing the set.

1


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+>A: ?A'+A ?+#5(?CB ?B?TM C 3C(=? (>TDMA= #CW ?TAT(C>

(>TC+:T(C>

With (ndis launching massi!e power de!elopment programme 3harat Dea!ylectricals =td., 3D=- introduced in late 70s =arge capacity 3oilers or ?team'enerators in the (ndian #ower ?cene, in collaboration with :ombustionngineering, +.?.A. These modern large capacity steam generators aredesigned to burn a !ariety of fuels and are e4pected to operate at di!ergentcomple4 conditions. 'enerally , any boiler furnace burning any or all types of fuels is susceptible to e4plosion or implosion resulting in e4tensi!e damage toe%uipment and or personnel. Distory of 3oiler operation re!eals that most ofo thefurnace e4plosions occur during start$up/shut down. ?ome of the attributable

causes are$

i- (mproper purging of the furnace, gas G air paths.

ii- (ncorrect or inade%uate ignition procedure.

iii- Maintaining fuel supply for too long a period without establishingcombusion.

i!- e$lighting burners too soon after a flame$out.

!- (ntroduction *of main fuel without ensuring ade%uate ignition energy.

Cperation of large capacity boilers therefore demands !ery safe G reliableoperating procedures. egardless of how alert the of operators are, mista"esoften happen. +nder some circumstances human response time is not %uic"enough to pre!ent accidents. ?ince elements controlled are large in numbersand comple4 in nature, human element is gradually substituted by automaticfeatures in 3urner Management and control systems for such boilers.

Iurnace ?afeguard ?uper!isory ?ystemH or I???H introduced by I3D=H intheir boilers is one such system and is designed to ensure the e4ecution of asafe and ordely operating se%uence during strart$up and shut$down of thecomple4 fuel firing e%uipment with minimum operator inter!ention.

TA>'>T(A= ((>'

The furnice deasign of such boilers is based on the tangential firing concept.(n a tangential fired furnace, the air and fossil fuels such as pul!eri&ed coal,


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oil or gas is inJected on an ele!ation basis through fuel no&&le assemblylocated at corner bo4 of the furnace fig.1-.

These no&&les are arranged to fire fuel tangentially at an imaginary circle inthe center of the furnace. AdJacent to each fuel no&&le is the pilot ignitor which

is located so as to fire directly across the line of admission to the main fuelsteam.

?olid angle optical flame scanners are strategically located at each corner for flame detection. uel air and au4iliary air damper associated with each corner wind bo4 are automatically regulated to distribute incoming air for optimumfiring conditions. iring is initiated on an ele!ation basis with ignitors pro!idingthe ignition energy. irect ignition of pul!eri&ed coal is recently introduced toa!oid usage of oil.

?B?TM #D(=C?C#DB

The urnace ?afeguard ?uper!isory ?ystem super!ise, command andmonitor the preparation, distribution and admission of fuel and air into thefurnace. The system protects against unsafe operation of the boiler bye4cluding improper action in operating se%uence G initiating trips whenapproaching unsafe conditions. The system operates on energise to openand energise to close/trip philosophy so as to ensure ma4imum safety anda!ailability.

The following operational functions are achie!ed through ???.

i- urnace purge super!ision.

ii- ?econdary Air amper :ontrol Modulating :ontrol-

iii- (gnitor Cn/Cff operation.

i!- Warm$up on/off operation.

!- Mill and feeder Cn/Cff operation.

!i- lame scanning.

!ii- 3oiler trip protection.

AA>'M>T C ??? ig$2-

The system consists of three basic parts that operate in +nison to pro!ide for ma4imum boiler protection and minimum nuisance trips.


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i- ?ystem :abinet

The most comple4 part is the system cabinet which is usually located in

the control e%uipment room. This cabinet houses the system logic and isresponsible for processing of all incoming signals/commands/feed$bac"and issue output command for field de!ices through interposing relays.This system also interface, secondary air$control sub$system and other boiler automatic control loops.

ii- Cperator;s #anel console insert

:onsole insert panel is located in the +nit :ontrol es". (t contains statusindicating lamps, pushbuttons for operator initiation of commandsincluding master fuel trip. Apart from gi!ing commands this insert also

displays !arious permissi!es@ feed$bac" and status signals.

iii- ield e!ices

The field de!ices form the rest of the system and consists of local or boiler front hardware such as pilot ignitors, fuel !al!es, positioning de!ices,pressure switches G flame scanners. Almost all these de!ices pro!idestatus signal and recei!e command signals from the system logic cabinet.

The system is functionally chec"ed out and fully similated in the factorybefore shipment to site.

C'A>(?AT(C> C ??? =C'(: ig-

The ??? is arranged in a hierarchically distributed concept with three le!els of controls@ !i&. +nit le!el ele!ation le!el and corner le!el control.

+nit le!el =ogic super!ises furnace purge, o!erall boiler conditions such as drumle!el, furnace pressure air$flow, etc. and initiates action to trip boiler, if dangerouscondition buildup by closing of the fuel inlet to the furnace.

The ele!ation control recei!es its permissi!es from the +nit :ontrol and thestart / stop commands from the operator;s console. The control logic for theele!ation depends on the type of fuel being used i.e. oil, coal, gas etc. theele!ation control initiates the starting and stopping of all corners in an orderlyse%uence.

The corner control logic recei!es its commands from the ele!ation control logicand computes the corner release conditions before acting on the ele!ation


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commands. (t also ta"es care of the safety/ protection functions of the corner andissues the corner trip commands.

?:T(C> 9 2

igital Dardware

3ac" ground

elay based ??? is in use in the power station for %uite some time now. Thecomponents used in implementing the relay logic include control contactors, latchrelays, lectro$pneumatic timers for Cn/Cff delays, etc.

or ma4imisng a!ailability, two reliable control supplies are used in the systemnamely 1105A: and 2205:. The : supply is ta"en from station battery whilethe A: supply is deri!ed from dual source with a bac"$up feeder and changeo!er panel or from +#?.

(n case of loss of A: power the trip functions are achie!ed by the : logicwhereby an oil trip !al!e or pul!eriser is tripped by the : power. (n case of failure of the : source, the trip functions are achie!ed by closing the corner no&&le !al!es, feeders and hot air gates which operate on 1105 A:.

With the emergence of solid state semi$conductor technology and the a!ailabilityof high reliability components the system logic functions could easily be reali&edusing solid state technology ensuring impro!ement with increased unita!ailability, low maintenance cost.

Apart from these ad!antages the solid state e%uipment offered si&e reduction,lower power consumption, use of lower operating !oltages etc. facilities such asimpro!ement in man$machine communication, a systematic fault annunciationphilosophym hierarchical and decentrali&ed structuring of the control systemcontribute greatly to impro!ed automation which has become a necessity in morecomple4 control system being used now$a$days.

5=C#M>T C DAWA

8eeping in !iew the abo!e ad!antages of the solid state system 3D= de!elopeda hardware family of cards called I:MC(:H for digital logic control application.This comprises of a family of printed circuit KK for 3inary control in power plantthrough which ??? system is being realised.

3D= introduced the hardware for ??? system for Thermal #ower ?tations andsome are already in operation. At the component le!el :MC? was chosen as thebasic technology for integrated circuits. This was done as this technology wasthen well pro!en and used in industrial systems. (t offers well "now ad!antages


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of better noise immunity, lower power dissipation, lesser current re%uirements,etc.

The mechanical construction of the modules, rac"s, cubicles, etc. are "ept inconformance to the e4isting (nternational practices such as uro$standard rac"s

G connectors.

At the module le!el these generally conform to the en!ironmental conditionstypical to power plants as per specifications of (: *)$2, (:$*0 and (:$226$


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simplifies the planning and engineering of the system. :hanges or e4pansion, if desired later, are found easy to incorporate.

(nput modules

These modules are used to interface the signals from field contacts to the controlsystem. ield contacts are interrogated through a fused 2


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partitioning of the system is strictly maintained. or each dri!e or !al!e in thesystem a dri!e control module has been assigned which would issue open/closecommand to the dri!e, monitor its field status and ammunciate the same onoperators console. The protection command to the dri!e control module assumeshighest priority.

The partitioning of the system is maintained by using different set of modules for each corner control, ele!ation control, etc. the modules for control of !ariousele!ations are mounted in separate cubicle sections. (n these cubicles, themodules controlling each corner are housed in separate rac"s. The dri!e controlmodules for the ele!ations are mounted on the lowest rac"s.

The ele!ation control logic is built using the group control and general purposelogic modules. The unit is also built using the general purpose logic modules.

The output commands to the field dri!es are issued through the interposing

relays mounted in the respecti!e ele!ation cubicles.

#CW ?+##=B

The system operates on L 2+>:(AT(C> ?B?TM

The fault annunciation philosophy is built so as to simplify the locatiosation of fault in the system.

(n case of fault in the system the following annunciations are a!ailable whichenable the operator to easily identify of the type of fault.

a- a fault lamp in the central annunciation panel glows warning theoperator.

b- ?imiltaneously a lamp on the cubicle door glows identifying the cubiclein which the fault has occurred.

c- A = on the 3uffer module in top rac" glows indicating the type of fault.


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d- Another = on the front plate of the dri!e control/input module glowsidentifying the dri!e where the fault has occurred.

This type of fault locali&ation results in reduced downtime and increaseda!ailability of the system.

?:T(C> 9

>'(>' T>?

Da!ing made its presence felt in the process industry, the microprocessors arenow being accepted by utilities in total power plant automation, with greater confidence. urnace ?afeguard ?uper!isory ?ystem is also being configured withthe microprocessor based controls. The programmable control system has thefollowing inherent ad!antages

- ?ystem is software based, hence allows logic changes to be easily madee!en in the field during commissioning using portable programmingunit.

- educed spare parts in!entory.

- (ncreased reliability and easier maintenance due to reduction in hardware.

- ?ystem self diagnostic features enable faster trouble$shooting.

- :T display and "eyboard/control optional- allows the operator to ha!e

an acti!e graphic display of the boiler fuel firing e%uipment and itsassociated !al!es, piping alarm switches, flame status/%uality. (t ,further enables the operator to select displays and optional control of boilers through :T.

- 3oth geographical and functional distribution of the system are possible. (nthe case of geographical distribution each local station is lin"ed to eachother through high speed data lin".

- ata lin" with plant computer system possible.

?B?TM A:D(T:T+

To meet !ery stringent reliability and !ery high a!ailability criteria of a furnaceprotection system, a highly effecti!e fault tolerant system architecture isnecessary. urther ??? being a hierarchically distributed system thedecentrali&ed structure should also be reflected in the control systemarchitecture.


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3D= is now introducing microprocessor based ??? system in their 3oilers. Atypical system configured for a 210 MW boiler is illustrated in the ig.<

The system architecture utili&es a multiple microprocessor configuration whereby,the control of different coal ele!ations is assigned to separate microprocessors

and further the control of important dri!es in the system is assigned toindependent dri!e control modules ha!ing their own dedicated micro$processors.

The microprocessors are assigned for the boiler trip functions M- inredundant mode. Bet another processor controls the unit functions li"e boiler purge, group control of scanner fans, seal air fans, etc. the !ariousmicroprocessor in the system are lin"ed !ia data highway using dual redundantco$a4ial cables. (n order to ensure ma4imum safety and a!ailability of the boiler,redundancies are built into the system, by suitably assigning the protectionfunctions, the dri!e control module as well as the se%uencing processor, both of which issue trip commands to the field dri!es under emergency conditions.

The con!entional operator;s console with push button controls and indicatinglamps may be lin"ed to the processors !ia the data highway. Dowe!er,commands to important dri!es and trip commands are hardwired directly tocorresponding dri!e control card. 3esides, a central 5+ and "ey$board may beconnected to the system !ia data highway.

The built redundancles in the system in ensure that failure of any processor doesnot endanger the boiler nor does it lead to any unwanted shut$down. The easylocali&ation of fault and FCn$line; replacement of a failed processor module with aspare unit is accomplished in a bumpless fashion, ob!iating the need of a boiler

shut$down.

(A'>C?T(: ?TAT(C>

A diagnostic station may be connected to the system which acts as a centralwor"ing place for commissioning ./ maintenance personnel. (t enablessuper!ision/ interaction with the entire control and monitoring system. Allmodules in the system monitor therein is alarmed through the diagnosite stationwhere the type and location of fault is displayed on :T.

#C'AMM(>'

The #rogramme or The ?ystem (s one Through asily +nderstandableunctional 3loc" Criented =anguage. #re$programmed software modules,brea"down the comple4 logics into simplified readily understandableprogrammes. The modularity also facilitates easy e4pandability.

:C>:=+?(C>


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The design of the urance ?afeguard ?uper!isory ?ystem is process orientedand ta"es into account the boiler design and fueld firing system, operationalcharacteristic and limitations and integrates them to ensure ma4imum safety,reliability and operational fle4ibility.

The control system logic can be accomplished with

a- lectromagnetic relaysb- Dardwired solid state electronics, or c- >ew generation of microprocessor based programmable controls.

A trend in emerging towards use of programmable control system. Three maincomponents that ma"e up the programmable control system are the F#ower ?upply, :entral #rocessing +nit and the input / output system. The centralprocessing unit is the heart of the system and uses the control programme which

has the fle4ibility of changing at site, using the programming panel. This uni%uefeature eliminates the need for wiring changes re%uired under the other twosystem, allowing economical modifications and e4pansion of the control systemwith impro!ed reliability.

The 3urner Management ?ystem is engineered and supplied as dedicatedcontrol systems as part of the steam generating unit.


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START UP OF KWU TURBINES

!en though starting of 8W+ turbines are similar to other design,automation and instrumentation a!ailable in this turbines. 3efore we go to thestart up procedure, let us e4pose oursel!es to the basic instrumentation a!ailable

in these type of turbines which is more important for operation and identifying theareas of fault.

AT? Automatic turbine run up system-$

?tarting the turbine from rest to turning gear operation, raising !acuumand yarm up the burbine, rolling synchroni&ing, loading and !ice !ersa i.e.,-shutting down in the re!erse re%uence.

?': ?ub 'roup :ontrol-

Automatic se%uential starting or shutting down of each group !i&., oilsupply, !acuum and turbine.

?=: ?ub =oop control-

Automatic interloc" for indi!idual e%uipment li"e pumps, or for a group of e%uipments li"e actuators.

?TAT+# 5(:

3y which the turbine if reset and the turbine stop !al!es are "ept opened.

With start up de!ice the starting can be done and speed can be raised upto 2


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ser!ice conditions 2 probes are continuously gi!ing reference and third onecomes into ser!ice when one of the two fails.

=CA >:

3eyond 20 of the load, load reference comes into ser!ice. or this loadcontroller has to be switched on. When the machine is on load, load referencecomes into ser!ice or this load controller has to be switched on when themachine is on load, load reference is more accurate than speed reference. =oadlimiter is also a!ailable. 3y selecting the set point on load limiter, the load iscontrolled in that limit.

N+>:B >:

With this the load will get !aried to maintain the fre%uency constant. (n our country it is !ery difficult to operate in this mode. Dence it is not put in operation.

>: ?T #C(>T ?# / =CA- 3=C:8

This occurs at !arious conditions. (t bloc"s the status of turbine for further raisingof speed / load due to the following conditions.

1- Turbine stress e!aluator fault2- #lunger :oil off D:-- ?5 ( :losed


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A+TCMAT(: :C>TC= (>TA:

This control comes in =#3# system. The set point gets !aried by 2 "gmore than initial pressure in eheater, the opening of =#3# !al!es straight awaygoes to 26 and maintains there till the setting raises upto 12 "g and afterwards

maintaining at 12 "g by !ariable opening or closing of =#3# !al!es.

(O ?T #C(>T

i4ed set point in =#3# control is the set point of DD pressure limit whatwe select.

?=((>' ?T #C(>T

?liding set point is the !ariable set point of DD pressure limit after synchroni&ing. The set point !aries directly proportional to the wheel chamber

pressure.

T+3(> ?T?? 5A=+TC

This continuously monitors the temperature !ariation across the metal of turbine causing shaft and !al!es and guides action. (t cautions the occurrence of thermal shoc" at any mo!ement. Turbine stress e!aluator gi!es the upper margin and lower margin on speed and upper and lower limit of loads on loadedconditions. (f turbine stress e!aluator is faulty, then it bloc"s further raising of speed or load. Any how, between *00 to 000 #M while raising the speed, theT? influence is bypassed so as to cross the critical speeds smoothly.

:(T(:A= ?#

The critical speed of the rotor for 210 MW ?ets-

D# rotor 70.6 #?D# rotor *


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OAM#= C ?':

Au4iliary oil pump 1 on

Au4iliary oil pump 2 on

Turbine speed $ / 2E60 #M

* #ressure oil pressure 9


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=ot us see in brief how to indetify the codes in this system.

A=#DA ?BM3C= >+M(:A=

?BM3C=

A A A > > A A > > >

M $ Main Machinery Turbine A $ +nits 9 including dri!esG 'enerator-

= $ ?team, condensate 'as 3 $ Deat (n change:ycle

: $ #arts of instrumentation,G control. : $ Measuring instruments

MA $ ?team Turbine $ :lose loop controlM" $ 'enerator. circutsMB $ :ontrol, 'o!erning, $ #rocessing of Measured

#rotecti!e system. 5alues.MAAA $ D# Turbine ' $ lectrical %uipmentMA3 $ (# Turbine :# $ #ressure MeasurementsMA: $ =# Turbine :T $ Temperature Measure $MA $ 3earing monts.MAW $ ?eal ?team :T $ #osition MeasurementsMA= $ rain :B $ 5ibration, 4pansionMA' $ :ondenser ?ystem MeasurementsMA> $ =# 3ypass := $ =e!el MeasurementsMA5 $ =ub CilMAO $ :ontrol :i!il ?ystemMAP $ Air ytraction=3 $ ?team ?ystem=3A $ Main ?team #iping=33 $ AD #iping=3: $ :D #iping=3W $ ?eal ?team #iping

>umerical symbol are gi!en to identify the indi!idual e%uipments.

>umber of panels for entire : G ( pac"age is ourteen. >ine #anels for :PP and i!e #anels for ::A.

::A $ ri!e control and 3inary signal :onditioning:PP $ Analog ?ignal :onditioning and Analog :ontrols.


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::A 1 $ unction group control, #rotection G interloc"s2 $ =imit 5alue Monitoring $ ri!e :ontrol interface< $ 3inary ?ignal :onditioning :ur!e 'enerator.6 $ ?ynchronising +nit 9 olay interface

::P 1 $ Turbine storess e!aluator 2 $ lectro Dydraulic Turbine :ontrol $ =# 3ypass G 'land steam control< $ Trubo!isory6 $ Ana log ?ignal :onditioning) $ =oad shedding elay10 $ Turbine #rotection11 $ Automatic Turbine test and 3inary ?ignal conditioning for A T T12 $ elays for ATT

START UP OF TURBINE:

T+3(> #CT:T(C>?

1- omoto trip from +:32- Manual Tripping from local- =ow 5acuum Trip lectrical-


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*- C!er speed test ?tri"er 1G2 Fdone at 000 #M on ATT7- ire protection$ :hannel 1)- ire #rotection$ :hannel$2E- =ow le!el in main Cil Tan" 2 out of from sonar probe-

10- =ow lub oil #ressure 2 out of from #ressure switches-11- 3oiler ir out12- Main steam Temperature =ow1- 'eneration #rotections.

PRE PARATION:

!INE C!EAR RET%RNED

$OWER %$$!' READ'

INTR%MENT RECORD DAAIR CONDN O, %C( ON

DM $!ANT GENERATION ON

COM$REOR ON ER*ICE

OI! $!ANT ON O$ERATION

'DROGEN $!ANT ON O$ERATION 2 Co2 C'!INDER

CIRC%!ATING WATER 'TEM COO!ING TOWER-INO$ERATION

DRG COO!ING WATER 'TEM IN O$ERATION

E!ECTRICA! ACT%ATOR O$ERATION CEC)ED

!E*E! IN OTWE!!- O)

!E*E! INDEAERATOR - O)

!E*E! IN (OI!ER DR%M - O)

!E*E! IN MAIN OI! TAN) -O)

$ROTECTION O, (,$/ CE$ CEC)ED IR*A!%E O, A!! .T. MOTOR CEC)ED


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C(= ?B?TM

CONDENATE 'TEM ETA(!IED

,EED 'TEM ETA(!IED

DIEE! GENERATOR READ'

CENTRI,%GE IN O$ERATION

ANA!'I O, OI! AM$!E

*A$O%R E+TRACTOR ,AN ON

A%+I!AR' OI! $%M$ IN ER*ICE

OI! TEM$ERAT%RE CONTRO! IN A%TO

OI! COO!ER WATER IDE CARGED

$ROTECTION AND INT(R!OC) CEC)ING

EA! OI! 'TEM INER*ICD

OI! TEM$ER T%(E 0 REACED

GATD*A!*E GEARING O$EN

AC)ING OI! $%M$ IN ER*ICE

T%R(INE ON T%RNING GEAR O$ERATION


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(>T =C:8? A> #CT:T(C>? C T+>(>' 'A

:D:8 1

?T# 1 ?T# 2

?=: AC# 1 C ?witch off AC# 1?=: AC# 2 C>?=: C# C esult A C # 2 :omes in

AC# 1 C> auto AC# 2 CC# C

:D:8 2

?T# 1 ?T# 2

?=: AC# 1 C> ?witch off AC# 2?=: AC# 2 C?=: C# C esult A C # 1 :omes in

AC# 1 C auto. AC# 2 C>

C# C

:D:8

?T# 1 ?T# 2

?=: AC# 1 C ?witch off AC# 2?=: ?C# 2 C?=: C# C> esult C # :omes in auto.

AC# 1 C> This test is done independently AC# 2 C or actuating each prossureC# C switch-


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:D:8 <

?T# 1

?=: PC# 1 C

?=: PC# 2 C>?=: PC# 1 C>PC# 1 C

?T# 2

?witch off PC# 1

esult

PC# 2 :omes in auto.

5A:++M ?B?TM

CEC) CONDENER ON $RING %$$ORT WITO%T $RO$

CIRC%!ATING WATER 'TEM CARGED

CONDENATE $%M$ ON ER*ICE IN RE CIRC%!ATION

TRO%G GC

T%R(INE ON T%RNING GEAR

*AC%%M (REA)ER C!OE

A%+I!IAR' $RD CARGED

WARM %$TO G!AND TEAM CONTRO!!ER

*AC%%M $%MTARTINGMAIN

ERECTOR TARTED.

O$EN DRAIN *A!%E

TART G!AND TEAM CONTRO!!ERAND )EE$ IN A%TO

Op"n 4lan5 6#"am EADER DRAINMA! 71


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A(> C#AT(C>

CARGE GC ON TEAM IDE

*AC%%M 8 0.12)G M2

!OAD 9 :

WITC O,, ONE O, TE *AC%%M

$%M$

TART *A$%%R E+A%T ,AN

*AC%M ACIE*ED

M R TARINER DRAIN O$EN CARGE MAIN TEAM !INE

CR !INE DRAIN O$EN

DRAIN (E, CR NR* O$EN

$ ($ DRAIN O$EN

E* EAT DRAIN I* EAT DRAIN O$EN

DRAIN (E,ORE INTERCE$TI*E *A!*E O$EN

DRAIN (E,ORE !$($ TO$ *A!*E O$EN

DRAIN A,TER INTERCE$TI*E *A!*E O$EN

DRAIN (E,ORE $C* O$EN

DRAIN A,TER $C* O$EN

DRAIN $ CAING O$EN

DRAIN (E,ORE E+TN NR*/23 O$EN

(' $A O$ERATION TART

O$EN $ & !$(' $A

A%TOMATIC CONTRO!INTER,ACE IN A%TO

!$($ CONTRO!!ER IN A%TO

D%M$ING O$ERATION


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KK

>umorical symbols are gi!en to indentify the indi!idual e%uipments.

>umber of panels for entire : G ( pac"age is ourteen. >ine #anels for:PP and i!e #anels for ::A.

::A $ ri!e control and 3inary signal :onditioning:PP $ nalog ?ignal :onditioning and Analog :ontrols.

::A 1 $ unction group control, #rotection G interloc"s2 $ =imit 5alue Monitoring $ ri!e :ontrol interface< $ 3inary ?ignal :onditioning :ur!e 'onerator.

DRAIN A,TER E+TN NR*/

23; O$EN

TEAM $%RIT' O)

RO!!ING TART

'NCRONIING

CARGING O, !$ & $EATER


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6 $ ?ynchronising +nit$ elay interface

::P 1 $ Turbine stress e!aluator 2 $ lectro Dydraulic Turbine :ontrol $ =# 3ypass G 'land steam control

< $ Trubo!isory6 $ Ana log ?ignal :onditioning) $ =oad shedding elay10 $ Turbine #rotection11 $ Automatic Turbine test and 3inary ?ignal conditioning for A T T12 $ elays for ATT

?TAT +# C T+3(>

KKKK

M(:C #C:??C 3A? #A??

1.1 ?B?TM ?:(#T(C>

The proposed ??? is foro a 210MW 3oiler with si4 coal and three oilele!ations. The system design is based on 33:;s control philosophy usingprocontrol # system hardware. The system has a decentrali&edhierarchical structure. The proposed configuration is for a functionallydistributed but geographically centrali&ed system. All the electronicmodules of the control system for the A?? will be housed in panelsplaced in the control room.


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To maintain the decentralised and hierarchical structure of ???, thedesign en!isages a local bus for control of each coal and oil ele!ation withthe oil ele!ation busses controlling the associated coal ele!ation too ref fig.1- i.e. the local bus for oil ele!ation 9 A3 also houses the controlmodules for coal ele!ation , etc.

urther two local buses are in turn lin"ed !ia the intraplant bus systemwhich is arranged in redundant mode. The operator commands fromconsole to the !arious local buses are connected through prefab cables.

1.2 (5 :C>TC= +>:T(C>?

The decentrali&ed structure of the system is further enhanced byassigning the control of important dri!es in the system to independentdri!e control modules no&&le !al!es, #ul!eriser, hot air gate etc-. Thesedri!e control modules which ha!e their own independent microprocessor

are programmed to ta"e care of the protection and manual interloc"s of the dri!e. They issue the open/close or C>/C command to the fielddri!e recei!e and further process its feedbac".

1. =C:A= 3+? TA(:

The chief components of the local bus are the bus traffic director 703501-and the bus circuit board 703=01-. The signal transmission se%uence onthe local bus is controlled by the bus traffic director. (t generates the localbus addresses cyclically. Two traffic directors are mounted on each localbus in redundant mode. At any instant of time one of the traffic directors is

acti!e while the other remains as a hot stand by.

1.< (>#+T G C+T#+T +>:T(C>?

(nput and output modules for the system are mounted on the local bus.The input modules recei!e the field status criterion and float this data onthe local bus, when addressed by the traffic director. This data which isfloated in normal and in!erse mode on the data lines is recei!ed by thedri!e control / processor modules on the local bus.

The output modules recei!e the updated status information e!ery cycle innormal and in!erse mode > G (-. This data is chec"ed for plausibilitybefore dri!ing the outputs and reJected in the e!ent of non agreement. Themodules in this case store the data, last recei!ed correctly. (n case nonagreement e4ists for more than 70ms an alarm is generated and themodule outputs are reset to FC;.

1.6 ?N+>:(>' G (>T=C:8(>'


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The se%uencing and interloc"ing of the ele!ation start / stop is done by theprogrammable processor modules 70#0- mounted on the local bus.These processor modules commnicate e4clusi!ely !ia the local bus. Theyrecei!e the status information and process them in accordance withinstructions, preprogrammed in the non$!olatile memory of the module

and transmit results !ia the local bus.

1.* #CT:T(C>

As mentioned earlier the protection functions of the indi!idual dri!es areta"en care by the respecti!e dri!e control modules. Additionally protectionsignals of the important dri!es i.e. no&&le !al!es, pul!erisers would also beprocessed by the programmable processor module 70#0- on the samelocal bus and trip command issued through the output modules. This tripcommand would be in parallel to the command issued by the dri!e controlmodule. This further enhances the safety of the boiler.

1.7 (>TA#=A>T 3+?

The status of dri!es in the local buses for !arious ele!ations arecommunicated to the local buses for unit trips purge etc !ia the intra plantbus. ?imilarly, the permissi!e condition / trip conditions are communicatedfrom the local bus for unit trip / purge to the local bus for !ariousele!ations !ia the intraplant bus.

Two entirely independent intra plant bus system are used for transmissionof redundant signals from the local buses. The two intra plant bus systems

are physically and electrically independent. The transmission se%uenceson the intraplant bus are controlled by the address transmitter, and thetransmission ta"es place through co$a4ial cable. Two nos of addresstransmitters are installed on each intraplant bus in a redundant mode. The!arious measures ta"en to ensure transmission reliability on the intraplantbus li"e time tolerance, parity bits, cyclic transmission etc together with thebus redundancy ensure the total system integrity for boiler protection.

1.) :C>5>T(C>A= C#ATC? :C>?C=

The start / stop commands to the dri!es in the system would be hardwiredfrom the miniature push buttons in the console to the respecti!e dri!econtrol and processor modules through prefab cables. A mosaic grid typeconsole insert would be pro!ided for the purpose.

1.E or trouble free testing, commissioning and maintenance of the system a!ariety of e%uipment are a!ailable.


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- ?er!icing, test and commissioning units for commissioning andmaintenance of the system.

- #rogramming units for programming the processing modules.

- iagnostic station 9 the central station for locali&ation and analysis ofplant system disturbances.

2.0 (A'>C?T(: ?TAT(C>

The diagnostic station with :T and "eyboard pro!ides a window to thewhole process. (t is the central wor"ing station for the dialogue with theentire control and monitoring system. This station is capable of modulare4pansion and performs the following functions

$ :ontinuous

(ndication and logging of the system hardware alarms in clear te4t. Thefailure of any dri!e control, input module field cable short circuit etc isalarmed on the diagnostic station.

$ Cn re%uest(ndication / logging of local bus signals(ndication / logging of internal operational !alues.(ndication / logging of marshelling lin"s in the local bus / intraplant buscouplers.Cptimising of control loops remote setting control parameters-#rint out of programme contents of programmable modules.

Dence in case of failure of any start / stop se%uence it is possible to get adisplay of !arious field input criterions, processor status etc on thediagnostic station and locali&e the faulty field component. A printer can beconnected to the diagnostic station for getting a hard copy.

2.1 MC>(TC(>' A> A>>+>:(AT(C> :C>:#T

ach module of the #C:C>TC= #1/


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epending on the type of the main function, the malfunction, theannunciation is either made !ia a hardwired output or !ia the local bus,together with the respecti!e data word of in a specific disturbanceannunciation word see fig.-

or e4ample

The wire brea" of a thermocouple is annunciated by means of adisturbance bit, which will be Trasmitted in the same data word as theanalog 5alue of this thermocouple.

The different disturbances in relation with an indi!idual dri!e control aretransmitted in a disturbance annunciation word of the dri!e controlmodule.

ach module has one hardwired disturbance annunciation output and a

red light emitting diode =- on the front plate for common annunciationof module failures.

With the = a faulty module can easily be detected in a station. Thehardwired disturbance annunciation outputs of all modules of one localbus system are hardwired according their significance to the inputs of theIdisturbance annunciation portH of the =3/(#3 coupler 703802 9 if a localbus system is connected to more than one intraplant bus channel andtherefore is e%uipped with more =3/(#3 couplers. These outputs will bewired only to one =3/(#3 coupler which will be defined as responsible for the ser!ice traffic with the diagnosis station respecti!ely the man machine

interface MM(-.

The =3/(#3 coupler combines the inputs on his Idisturbance annunciationportH together with =3/(#3 coupler internal disturbance annunciations withthe disturbance annunciation words transmitted !ia the local bus and forma specific diagnosis word.

The diagnosis word is called up cyclically !ia ser!ice addresses by thediagnosis station respecti!ely MM(.

The annunciation signals can be displayed on the :T with type locationand clear te4t of the specific fault.

3y calling up the diagnosis word of each local bus station cyclically thediagnosis station, respecti!ely the MM( can also detect a failure of a localbus system.


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5arious possibilities for interconnection of these are pro!ided, dependingon the si&e of the control and monitoring system and the type ofcommunication means employed.

The following shows an e4cerpt of a preferred !ersion

?M 0 Q ?tation failure(nterconnection of all ?M outputs from central modules e.gbus traffic director, power supply- which shut down an entirestation in the e!ent of a disturbance.

?M 1 Q (nput module disturbance(nter connection of all ?M outputs from input modules.

?M 2 Q Module isturbance without input modules-(nter connection of all ?M outputs from processing or

output modules.

?M Q edundant system failure(nter connection of all ?M outputs from modules used inredundant mode.

?M 1 Q (nput module disturbance(nter connection of all ?M outputs from input modules.

?M? Q ?imulation(nter connection of all ?M outputs from all modules etc. (n

addition to acti!ation of the annunciation output thedisturbances detected also ha!e an influence on the functionof the module concerned depending on the type of disturbance.

. #C'AMM(>' =A>'+A' #C:C>TC= #10

The programme documentation for programmable processors of theprocontrol # family is based on functional control diagrams which pro!idethe foundational information for programming. All tas"s to be performed bythe processors are represented on these diagrams by symbols for A>,C etc-. An instruction code is assigned to e!ery symbol.


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The power supply re%uired for the operation of the procontrol # system is2

electrical tests

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