automatic turbine run up system

April 18, 2023 Gyanendra Sharma - NPTI Delhi 1

AUTOMATIC TURBINE RUN UP SYSTEM(ATRS)


Presentation outline

•Overview of Plant Controls

•Functions of ATRS

•Structure of ATRS

•Program Structure of ATRS and Turbine protection

Gyanendra Sharma - NPTI Delhi

April 18, 2023 3

MAN-MACHINE-INTERFACE

OPERATOR

INSTRUMENTATION & CONTROL

PLANT


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POWER PLANT CONTROLPOWER PLANT CONTROL

UNIT CONTROL

BOILER TURBINE GENERATOR


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MEASUREMENT

CLOSE-LOOPCONTROL

OPEN-LOOPCONTROL

PROTECTION

MONITORING

INSTRUMENTATIONANDCONTROL


ADVANTAGES OF AUTOMATION

• OPERATING PERSONNEL FREED FROM ROUTINE TASKS.• INCORRECT INTERVENTIONS IN THE PROCESS AVOIDED.• STRESS ON EQUIPMENT REDUCED.• PLANT OPERATIONS GEARED FOR MAXIMUM EFFICIENCY.• INCIPIENT FAULTS RECOGNISED QUICKLY.• ON FAULT OCCURRENCE, IMMEDIATE AND LOGICAL INTERVENTION

POSSIBLE.


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A. CONTROL SYSTEM: ANALOG (CLOSE LOOP)

- ELECTROHYDRAULIC CONTROLLER (EHC) - TURBINE STRESS EVALUATOR (TSE) - LOW PRESSURE BYPASS CONTROLLER (LPBPC) - GLAND STEAM PRESSURE CONTROLLER (GSPC)

BINARY (OPEN LOOP)

- AUTOMATIC TURBINE RUN UP SYSTEM (ATRS) - AUTOMATIC TURBINE TESTER (ATT)

B. MONITORING & MEASUREMENT SYSTEM - TURBINE SUPERVISORY INSTRUMENTATION (TSI) - MEASURMENT OF PARAMETERS LIKE, TEMP.,PRESS.,LEVEL etc.

C. PROTECTION SYSTEM

TURBINE C&I PACKAGE CONSISTS OF THE FOLLOWING SYSTEMS:


HIERARCHY OF CONTROL

UNIT CONTROL

GROUP CONTROL(WHEN, HOW MANY,WHICH)

SUB-GROUP CONTRL-1 SUB-GROUP CONTRL-2

CONTROL INTERFACE

SWITCH GEAR (MCC)


CONCEPT OF C&I IN THERMAL POWER STATION

UNIT CONTROL

CLOSED LOOPCONTROL

FUNCTIONAL GROUPCONTROL

PROT-IVELOGICS

DATA PROCESS-ING, ALARMANNUNCIATION

SIGNAL CONDITIONINGALALOG, BINARY

CONTROL INTERFACE

MOTOR CONTROL CENTRESWITCH GEAR

M M DRIVESSIGNAL TRANSMITTER

ANALOG AND BINARY

SIGNALS

CRT /MMI DISPLAY UNIT IN OWS

LOGSCONTROL ROOM

AUTOMATION

EQUIPMENT

PLANT INTERFACE

EQUIPMENT

PLANT (FIELD)

OPERATOR


AUTOMATIC TURBINE RUN-UP SYSTEM

TASKS PERFORMED:• SWIFT,ACCURATE AND OPTIMUM STARTUP ( INCLUDING SYNCHRONISATION AND

LOADINING) OF TURBINE• MAINTAINING OIL SUPPLY• BUILDING UP AND MAINTENANCE OF VACUUM

FEATURES :• BASED ON FUNCTIONAL GROUP CONTROL PHILOSOPHY• EACH FUNCTIONAL GROUP ORGANISED AND ARRANGED IN ‘SUB-GROUP CONTROL’, ‘SUB-LOOP

CONTROL’, AND ‘CONTROL INTERFACE’• OPERATING MODES AVAILABLE: - MANUAL MODE ( OPERATOR GUIDE) - AUTOMATIC MODE - STEP BY STEP MODE


ATRS STRUCTURE OIL SYSTEM, VACUUM SYSTEM, TURBINE etc.

GC

SGC SGC

SLC SLCSLC

CI

SGC

CI


GROUP CONTROL: Decides WHEN, HOW MANY & WHICH SGC shall be operating and stopped.

SUB GROUP CONTROL: Contains the sequential logics for switching drives ON and OFF. Perform sequence in STEPS, issue commands and get Checkbacks.

SUB LOOP CONTROL: can be switched ON & OFF manually. Receive commands from GC, SGC and also Manual

CONTROL INTERFACE: Standard Interface between the command transmitters and receivers in the plant, undertakes all necessary signal processing and monitoring.

SYSTEM OPERATION MODES:

AUTOMATIC,SEMI AUTOMATIC,OPERATOR GUIDE


ADVANTAGES OF ATRS• ELIMINATES HUMAN ERROR • PROVIDES MAXIMUM PROTECTION AGAINST MALFUNCTIONS• OPERATOR’S TASK LESS ARDUOUS• ENABLES SAFE, SMOOTH, STRESS CONSISTANT AND OPTIMUM WARM-UP,

ROLLING AND SYNCHRONISATION OF TURBINE IN LEAST POSSIBLE TIME• INCREASES PLANT AVAILABILITY• REDUCES STARTING TIME WITHOUT IMPAIRING LIFE• MEETS EMERGENCIES AUTOMATICALLY• ALL PLANT OPERATING CONDITIONS CATERED TO BY CRITERIA DEPENDANT

PROGRAMMING• INCREASED OPERATING FLEXIBILITY, SAFETY AND RELIABILITY


ATRSAUTOMATIC TURBINE RUN UP SYSTEM

• Start up and Shutdown sequence performed in reliable way

• Protect drives and related auxiliaries• Uniform and sequential information to operator about the

process• Distinct information about the nature and location of

faults


STEP 01

STEP 02

&

START DRIVE A

DRIVE A ON

MONITOR & BLOCKING TIME

MONITOR & BLOCKING TIME

OPEN DMPR A



SUB GROUP CONTROL ( SGC):• SGC executes commands to bring the equipment upto a particular defined

status. • The commands are executed in a predefined sequence in the form of steps. • Desired number of criteria act as preconditions before the SGC can take off

or execute its defined sequence. • The functional group continues to function automatically all the time

demanding enabling criteria based on the process requirements and from other FGs, if required.

• In case the desired criteria is not available, the system would automatically act in such a manner as to ensure the safety of the main equipment.

• The sequence is programmed in the processor. The process signals are acquired through the input modules and are available on the bus.



WAITING AND MONITORING TIME FOR STEPS:

Waiting Time : It implies that the subsequent step will not be executed unless the specified

time elapses. If no waiting time is specified, the next step gets executed as soon as the enabling criteria are fulfilled.

Monitoring Time : It is the time required for executing the command of any step as well as the

time required for appearance of criteria for the next step. Under healthy conditions it should happen within the specified time, otherwise an alarm is initiated. Whenever there is uncertainty regarding the time required for completing a particular task, such as warming-up, pulling vacuum etc., the monitoring time is blocked.


PROGRAM STEP OF A SUBGROUP CONTROL

02

FROM STEP 1STEP CRITERIA FOR STEP -2

BYPASS CRITERION

PROGRAM LOOP

WAIT

50s

MO TIME

20s COMMAND

1

2

&

&

1

&

• STEP 2 ( START UP PROGRAM) WITH 2 STEP CRITERIA, 2 COMMAND

OUTPUTS AND A MONITORING & WAITING TIME .

• WITH ADDITIONAL PROGRAM LOOP CONTROL AND A BYPASS

CRITERIA FOR STEP 1

• WAITING OR MO TIME CAN BE PROGRAMMED FOR 0.1 SEC TO 999

MIN.

• NOS. 1-49 USED FOR START-UP, 51 TO 99 FOR SHUTDOWN PROGRAM.

EXAMPLE



WAITING AND MONITORING TIME FOR STEPS:

• ATRS can be switched on at any stage after completing certain tasks manually, if so desired. In such cases, the SGC program quickly scans through the steps and starts executing from the stage upto which the tasks have been completed manually. This is achieved by incorporating suitable overflow /bypass conditions in the logic.



• ATRS CONTROLS:

1. ATRS is organised in the following four Sub-Groups :• Oil supply• Evacuation• Turbine• HP CONTROL FLUID

2. SGC issues commands either to the SLC or directly to the drive through the Control Interface.

3. Each of these SGCs has its subordinate SLCs and CI modules. These SGCs in conjunction with the turbine governing system , TSE and the auto-synchroniser accomplish the function of start-up of the TG set.



SUB-LOOP CONTROL (SLC) :• A SLC, when switched on, actuates the equipment and brings it to the desired

status as demanded by the process and there is no sequence logic involved in it.

• SLC is like a watch-dog performing an assigned duty.

• All mechanical equipment which need to be switched on/off based on process consideration are hooked-up in various SLCs. Standby equipment is also interlocked in SLCs.

• SLC can be switched on either manually or through SGC and issues commands to the drive control level.

• SLC logic is also realised in the processor module.



CONTROL INTERFACE (CI) :• Each remote controlled drive has a dedicated CI module which acts as a

standard interface between the transmitters and receivers in the plant and undertakes all necessary signal processing and monitoring.

• The CI module receives manual commands from the process keyboard/inserts, active protection signals and enabling signals from the protective logic, as well as automatic control commands from the SGC/SLC.

• It interlocks the input commands according to their priority and validity and then passes actuation signals to the interposing relays in the switch-gear.

• The status checkbacks received from the switchgear or actuators are monitored, processed and transmitted to VDU/desk tiles, the protective logic and the SGC.


AUTOMATIC TURBINE RUN-UP SYSTEMCONTROL INTERFACE (CI) : (Continue--)• These modules have the firmware which defines the standard function of

the module and its signalisation mode as well as the programmable logic for the drive protection and the permissive interlocks. The drive level automation tasks related to the respective drive is realised through the programmable logic.

• The module has hardwired inputs and outputs for connection of feedback signals and commands to the switchgear together with local bus interface for signal exchange via the system bus.



ATRS STRUCTURAL SYSTEM:

• ATRS IS ORGANISED IN THREE SGCs :

1. SGC-TURBINE :

SGC Turbine acts directly on the following systems :

• Sub-loop Control (SLC) Drains.• Warm up Controller.• Starting Device of turbine governing system.• Speed & Load Setpoint devices of turbine

governing system.• Auto-synchroniser.




2. SGC-OIL SUPPLY :

SGC oil supply directly acts on the following system :

• Sub-loop control (SLC) turning gear.• SLC auxiliary oil pump 1.• SLC auxiliary oil pump 2.• SLC emergency oil pump.• SLC jacking oil pump.




3. SGC-CONDENSATE & EVACUATION :

SGC- Condensate & Evacuation directly acts on the following systems :

• Sub-loop Control (SLC) condensate extraction pumps.• Starting ejector, if provided.• Main ejectors / vacuum pumps (as applicable).• Vacuum breaker.




3. SGC-HPCF :

SGC- HPCF acts on the foll :

• Sub-loop Control (SLC) HPCF• SLC HPCF pumps• HPCF pumps• HPCF re-circulation pumps• LPCF temp control valve



3. SGC-HPCF :• Both CF PUMPS GET SWITCHED ONTHRU SLC. IN

CASE RUNNING PUMP DOES NOT DEVELOP THE REQUIRED PRESS, THE STANDBY PUMP GETS SWITCHED ON

• AFTER GETTING THE REQUIRED CF PRESS SLC HEATING IS PUT ON & CF CIRCULATION PUMP WHICH FEEDS THE REGENERATION CKT IS ALSO PUT ON. TEMP CONTOL VLV IS PUT IN AUTO MODE TO REGULATE THE TEMP.

• CF TEMP IN THE TANK IS MAINTAINED BETWEEN 55 TO 57 C BY SWITCHING ON/OFF THE CF HEATER THRU THE SLC. IN CASE CF TEMP IN HTR EXCEEDS > 65 C THE HEATER IS SWITCHED OFF

• IN SHUTDOWN PROG ALL THE PUMPS ARE SWITCHED OFF AND SLC IS PUT OFF. SLC HEATING IS KEPT ON TO MAINTAIN THE TEMP REQUIRED FOR THE NEXT STARTUP.


TURBINE START-UP / SHUT-DOWN CONTROL, OVERVIEW

SUB-GROUP ( TURBINE START-UP / SHUT-DOWN)

SUBLOOP DRAIN VALVE

SUBLOOPLP-WATERINJECTION

MECHANICALHYDRAULICCONTROL(MHC)

ELECTRO-HYDRAULICCONTROL(EHC)

SEALSTEAMCONTROL(SSC)

TURBINE TRIPSYSTEM(TTS)

TURBINE STRESSEVALUATOR

LP WATERINJECTION

AUTOMATICSYNCHRONIZER

DRAIN VALVES

GENERATORMAIN CKT.BREAKER

THYRISTORVOLTAGEREGULATOR(TVR)

CRITERIA

CRITERIA

AUTO-ON/OFF

AUTO ON/OFF

AUTO ON/OFF

MANUAL ON/OFF

MANUAL ON/OFF

MANUAL OPEN/CLOSE


SGC-DISPLAY4 6 8 7 5

1

3

2

1. PUSHBUTTON “SHUTDOWN”2.PUSHBUTTON “STARTUP” OR “OPERATION”3.PUSHBUTTON “AUTOMATIC ON/OFF”4.LAMP “SHUTDOWN PROGRAM”5.LAMP “STARTUP” OR “OPERATION” PROGRAM6.LAMP “AUTOMATIC OFF”7.LAMP “ AUTOMATIC ON”8.LAMP “FAULT”


SLC-DISPLAY

2 3 4

1. PUSHBUTTON “MANUAL ON/OFF”2.LAMP “SLC OFF”3.LAMP “ FAULT”4.LAMP “SLC ON”

1


DRIVE INTERFACE-DISPLAY

3 4 5

1. PUSHBUTTON “OFF” (CLOSE)2. PUSHBUTTON “ON” (OPEN)3. LAMP “ OFF” (CLOSE)4. LAMP “FAULT”5. LAMP “ON” (OPEN)

1 2


EXPLANATION OF KWU IDENTIFICATION SYSTEM (KKS)

0 1 2 3A NAAANN AANNN AANN

A 1MAJ15 AP001 XB01

ORDINAL SECTION

GENERAL

EXAMPLE

SIGNAL IDENTIFICATION

CONSECUTIVE NO. OF EQUIPMENT

TYPE OF EQUIPMENTNO. OF SUBGROUP

PLANT GROUP (FUNCTIONAL GROUP)

NO. OF UNIT


April 18, 2023 34

PROTECTION SYSTEMFOR

STEAM TURBINE


TURBINE PROTECTION SYSTEM

TASK PERFORMED :

• PROTECTS TURBOSET FROM INADMISSIBLE OPERATING CONDITIONS

• PREVENTS DAMAGE IN CASE OF PLANT FAILURE

• FAILURE OCCURRENCE REDUCED TO MINIMUM



ADVANTAGES :

• DETECTION OF UNIT IRREGULARITIES

• PREVENTION OF UNIT OVERSTRESSING DUE TO TRIPS

• RELIEF OF OPERATING PERSONNEL FROM QUICK AND CORRECT DECISION TAKING



HYDRAULICTRIP SYSTEM

ELECTRICALTRIP SYSTEM

EXTENDEDTURBINE PROT.

PROT. CRITERIAFROM OTHER AREA

- OVER SPEED TRIP DEVICE 1/2- VACUUM TRIP DEVICE- HAND TRIP LEVER(LOCAL) 1/2

- MANUAL REMOTE TRIP ( UCB)- LOW VACUUM TRIP- LOW LUBE OIL - FIRE PROT. TRIP-BRG METAL TEMP-AXIAL SHIFT-HP/IP TOP/BOTDIFF TEMP HI

- LP EXH. STM. TEMP. > MAX

-GENERATOR PROTECTION

- MASTER FUEL TRIP RELAY ENERGISED

- BOILER PROTECTION OPTD.



GENERAL :

• The electrical trip system comprises of two identical and independent relay based trip channels viz. electrical trip channels 1 & 2.

• Both channels are connected to different (two) trip solenoid valves.• All command signals for turbine trip are hooked up with both the channels.• Actuation of any of the channels energises the respective trip solenoid which in

turn trips the turbine. • Each channel is realized in a local bus. Both the local buses are completely

independent of each other and input modules, processor module and output modules reside on each.



GENERAL :• Trip signals from the sensors / field instruments are conditioned and distributed to

both the channels (local buses) via hardwired modules.

• Realisation of 2 out of 3 trip logic is carried out in the local bus. On detection of a fault in any one of the input signals to a channel, the configuration for that channel changes from 2 out of 3 to 1 out of 2 and is annunciated. Further failure in a channel changes the configuration to 1 out of 1.

• Trip signal from each of the local buses acts on 3 relays in 2 out of 3 combination.



CYCLIC TEST :• Both the channels are tested periodically, even while the turbine is running.

• Cyclic testing is done automatically at preset intervals and can be blocked from the protection cabinet, if desired.

• This testing can also be initiated manually from the cabinet.

• Only one channel can be tested at a time. Online testing is done by simulating the trip signals and it determines faults in the input modules, processor modules, output modules or the trip relays.

• These faults can be acknowledged from the cabinet. Next cycle test can only be carried out after acknowledging the fault.



TRIPPING CRITERIA :

1. CONDENSER VACUUM VERY LOW :• This is a back up protection to the hydraulic low vacuum trip device.• The protection acts if absolute pressure in the condenser rises

above 0.3 Kg/cm2 (abs).

2. LUBE OIL PRESSURE LOW :• The protection acts if the lube oil pressure before thrust bearing decreases to 1.2Kg/cm2 . • The trip signal is initiated by three pressure transmitters in 2-out-of-3- logic.



TRIPPING CRITERIA :

3. FIRE PROTECTION :• The protection acts in the event of any of the following conditions :

i) Fire protection switch, either in unit control room or in

machine hall, operated.ii) Level in main oil tank falls to a very low value, indicating substantial leakage of oil from the system.

The command signal under condition (ii) is initiated from three level transmitters in 2-out-of-3 logic cofiguration.



TRIPPING CRITERIA :

4. HP EXHAUST STEAM TEMPERATURE HIGH :

• The HP exhaust steam temperature protection circuit causes the exhaust sections of the turbine, the blading and the extraction points against overheating.

• Under extreme operating conditions the HP turbine can be run at low flow rate and simultaneous relatively high back pressure. This prevents the steam from expanding, which causes the exhaust steam temperature to rise ( > 5000C).

• The temperature is measured by means of three thermocouples and protection criteria is derived in 2 out of 3 logic.



TRIPPING CRITERIA :

5. TURBINE TRIP SWITCH OPERATED :

• The protection acts when the turbine trip switch in unit control room is operated manually.

6. TRIP COMMAND INITIATED FROM ATRS :

• The protection acts when the trip command signal is initiated from the Automatic Turbine Run-up System .



TRIPPING CRITERIA :

7. GEN. PROTECTION OR MFT- RELAY ENERGISED :• In the event of generator faults under Class-B trip both the turbine trip channels

are actuated to trip the turbine. In such a case the generator protection acts through Reverse Power Relays.

• In the event of generator faults under Class-A trip or in the event of boiler "Master fuel trip relay" energised, command signal for turbine trip shall act simultaneously and independent of other equipment trip out sequence.

8. OPERATION OF REVERSE POWER RELAY :• The command signal is initiated with a time delay of 10 seconds after any of the

two reverse power relays have operated.


THANK YOU

automatic turbine run up system

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