GE Industrial Systems

SPEEDTRONICTM Mark VI TMRFeed Pump Turbine Control

These instructions do not purport to cover all details or variations in equipment, nor toprovide for every possible contingency to be met during installation, operation, andmaintenance. If further information is desired or if particular problems arise that are notcovered sufficiently for the purchaser�s purpose, the matter should be referred to GEIndustrial Systems.

This document contains proprietary information of General Electric Company, USA, and isfurnished to its customer solely to assist that customer in the installation, testing, operation,and/or maintenance of the equipment described. This document shall not be reproduced inwhole or in part, nor shall its contents be disclosed to any third party without the writtenapproval of GE Industrial Systems.

Section Page

Introduction..................................................................................................................2Architecture .................................................................................................................2Inputs and Outputs .......................................................................................................5Control and Protection Functions ................................................................................6

Application Software Arrangement ......................................................................6Speed Control .......................................................................................................6Valve Control .......................................................................................................8Trip Protection......................................................................................................9Contact Input Trips .............................................................................................10Overspeed Protection..........................................................................................11Thrust Wear Protection.......................................................................................13Vibration Protection............................................................................................14Eccentricity Monitor ...........................................................................................14

Packaging...................................................................................................................15Power .........................................................................................................................16Operator Screens........................................................................................................17

gGE Industrial Systems

GEI-100474

CIMPLICITY is a registered trademark of GE Fanuc Automation North America, Inc.Ethernet is a trademark of Xerox Corporation.SPEEDTRONIC is a trademark of General Electric Company, USA.Windows NT is a registered trademark of Microsoft Corporation.

2 •••• SPEEDTRONIC� Mark VI TMR Feed Pump Turbine Control GEI-100474

IntroductionThe feed pump turbine control is part of the SPEEDTRONICTM Mark VI family ofturbine controls which are available for all GE turbines. The control is designed toprovide a small core of basic control functions that can be expanded in smallincrements for various levels of control, protection, and monitoring for the turbine,the auxiliary systems, and the pump.

Feed pump turbines are commonly applied in pairs with both pumps required for fullload on the main unit. The typical Mark VI control for this application is a tripleredundant control system (TMR), which contains the control and protection for bothturbines. Each turbine can be operated independently, and separate field terminationsare provided to facilitate maintenance of one turbine while the other turbine isrunning. Individual TMR or Simplex controls can be supplied for each turbine, ifrequired.

Several levels of operator interface are available. These include an operator interfacethrough a communication link from a plant distributed control system (DCS), a localor remote operator interface from a PC, or a hardwired interface. In addition, acommon PC based operator/maintenance interface and common softwaremaintenance tools can be provided for a Mark VI feed pump turbine control, a MarkVI reheat steam turbine control, and an EX2000 generator excitation control withpeer-to-peer communications on an Ethernet network.

ArchitectureThree control modules are supplied with identical hardware and software for thecritical control and protection functions. Each module consists of a card rack witheither a 13 slot or 21 slot VME back-plane with a processor card, communicationcard, and I/O cards. An example analog I/O is the automatic speed/flow referencefrom the feedwater control system. The signal for turbine A (typically 4-20 mA) isconnected to a terminal board, which is separate from the terminal board for turbineB. The signal is conditioned with passive circuits on the terminal board and thenconnected internally to the three control modules. An analog I/O card in each moduleconverts the signal from analog to digital for transmission to the communication cardthat selects the median value of the turbine A speed/flow reference from the threeanalog I/O cards. The voted value is then sent to the processor card in each modulewhere the application software is executed. The elapsed time to read every input,vote the data, execute the application software, and output to the control valves is 20ms (the frame rate). Diagnostics continuously run during this time to determine anydiscrepancies in the voted data. If a fault is detected, the defective card can bereplaced while the turbine is running.

GEI-100474 SPEEDTRONIC� Mark VI TMR Feed Pump Turbine Control •••• 3

PS

<R>Control Module

X

PS

Y

PS

<T>Control Module

Z

<S>Control Module

Ethernet

<P.A> <P.B>

Emergency OverspeedProtection Modules

Controllers 1. Control 2. Protection 3. Monitoring

CIMPLICITYR Display SystemWindows NTTM Operating System

Ethernet

Unit Data Highway

Operator / MaintenanceInterface

Communications To DCS1. RS232 Modbus Slave/Master2. Ethernet TCP-IP Modbus Slave3. Ethernet TCP-IP GSM

To Mark VI Reheat Steam Turbine Control

To EX2000 Generator Excitation Control

P.S.CPUI/O

P.S.CPUI/O

P.S.CPUI/O

Ethernet - IONet

Softw

are

Votin

g

Ethernet - IONet

Ethernet - IONet

X

Y

Z

P.S.CPUI/O

P.S.CPUI/O

P.S.CPUI/O

Typical Control System Architecture


An Ethernet based IONet is used to transmit data between the control modules andthe emergency overspeed modules that are used on turbines that do not have amechanical overspeed bolt. In these applications, the median value of three passive,magnetic pickups provide speed feedback from each turbine to the control modules,which perform speed control and the primary overspeed protection. Three additionalspeed sensors are used for an independent emergency overspeed signal to thecorresponding emergency overspeed module for that turbine. Two out of threemagnetic relays vote the resultant primary and emergency overspeed trip outputs tothe hydraulic trip solenoids. In addition, triple redundant trip solenoids are suppliedon each turbine to maximize the system fault tolerance.

For retrofit applications, an emergency overspeed module is not needed because theturbine already has a mechanical overspeed bolt. The two existing speed sensors areused for speed control and primary overspeed protection. The third speed sensor isalready connected to a tachometer, and this instrumentation is normally retained. Amodification kit is available to replace an existing mechanical overspeed bolt with anemergency overspeed module. This modification also requires that the existingsingle, energize-to-trip solenoid be replaced with a new triple redundant, de-energizeto trip solenoid system for reliability.

The processor card in each control module has an Ethernet port for communicationto a PC based operator / maintenance interface with a GE CIMPLICITY graphicsdisplay system and a Windows NT operating system. The PC is commonly referredto as the Human Machine Interface (HMI). One PC can be used for both turbines ifdesirable, and it can be used for a variety of communication links to the plant DCS.This Ethernet network is called the Unit Data Highway (UDH), and it can also beused for peer-to-peer communications with a Mark VI for the reheat steam turbineand associated controls such as the EX2000 generator excitation system for the mainunit.

The HMI has full operator capability to issue any command or monitor any datapoint from either turbine with the local high resolution time tags for alarms (20 ms)and Sequence of Events (SOE) (1 ms). It can be connected on the UDH tosimultaneously monitor the Mark VI control for the feed pump turbines, the reheatsteam turbine, and the EX2000 generator excitation system on one or dual redundanthighways. Redundancy is implemented by connecting each highway to a separateEthernet driver in a separate control module. Other available features in the HMIinclude trending at 20ms, logic and analog forcing, and time synchronization eitherto a time source from the Plant DCS or directly to a global positioning satellite(GPS).

Operator displays normally show turbine A on the left side and turbine B on the rightside to allow operators to monitor both turbines simultaneously. Names ofapplication software data points have a suffix _A and _B to clearly distinguish theturbine to which they are being applied.


Inputs and OutputsI/O circuitry is designed for direct interface to the sensors and actuators on theturbine to eliminate the need for interposing equipment with its resultant single pointfailures, maintenance, and spare parts.

Typical I/O Allocations in TMR Control Systems

I/O Category �A� Turbine �B� Turbine Additional I/O Blocks NotesContact Inputs 24 24 24 125 V dc from Mark VI

Optical isolation, 1 ms SOERelay Outputs 12 12 12 Magnetic relays with form C contact

outputsTrip Solenoids 1/2/3 1/2/3 As requiredSpeed Inputs• Primary• Emergency

2 or 33

2 or 33

2 retrofit, 3 new unitsIn place of mechanical OS bolt

Servo Outputs 2 2 2 Only 1 needed per turbineLVDR Inputs 6 6 Only 4 needed per turbine4-20ma Inputs 10 10 104-20/0-200 Out 2 2 2 (1) 4-20 mA and (1) selectable4-20ma Outputs 0 0 16 Option for monitoringProximitors• Vibration• Position• Reference

841

841

841

Includes: 1X, 2X vibration, phase angle,buffered outputs with BNC connectorsfor remote monitoring.

RTD Inputs 0 0 16 Option: software linearizationGrounded or ungrounded10 ohm copper, 100/200 ohm platinum,120 ohm nickel

Thermocouples 0 0 24 Option: software linearizationGrounded or ungroundedTypes E, K, J, T


Control and Protection FunctionsThe following control and protection functions are supplied with most controlsystems and implemented similar to the following descriptions. Many other featuresare available as required for the application.

• Speed Control

• Valve Control

• Trip Protection

• Contact Input Trips

• Overspeed Protection

• Thrust Wear Protection

• Vibration Monitor

• Eccentricity Monitor

Application Software ArrangementThere are four software segments in the Mark VI that contain application software.They are designed for independent operation of each turbine. These segments areexecuted sequentially in the order shown.

• SEQ_T1A Speed Control and Valve Control Turbine A

• SEQ_T2A All Other Control and Protection Turbine A

• SEQ_T1B Speed Control and Valve Control Turbine B

• SEQ_T2B All Other Control and Protection Turbine B

Application software for turbine A has an _A suffix, and application software forturbine B has a _B suffix. This enables operator and maintenance personnel toquickly identify which turbine the software applies to regardless of whether it isbeing monitored on an operator/maintenance interface PC or read in thedocumentation. There is a very small amount of software that is generic to the MarkVI system, which has no suffix such as the common alarm management system,power supply diagnostics, and the like. Although the alarm management software isgeneric, the application software that initiates these alarms is turbine specific withthe _A and _B suffix, and the alarm messages which appear on the monitor contain a(A) and (B) designation. All software documentation includes the (A) and (B)designation including the 1 ms SOE log on the printer.

Speed ControlThe Mark VI determines that the unit is stopped by monitoring the median value ofthe three passive speed pickups and the key phasor. A zero speed indication fromboth signals is required to initiate the zero speed logic (L14HR_A/B). A zero speedpermissive is provided to the turning gear based on this logic. These are dry, form Ccontacts from magnetic relays on the TRLY terminal board. Separate relay terminalboards are provided for the contact outputs to turbine A and turbine B.

Any significant discrepancy between the three speed signals initiates a diagnosticalarm which specifies the specific speed signal that is in disagreement, but theapplication software for all three control modules <R><S><T> continues to run onthe median value (TNH_A/B). Any one of the three controllers can be de-energized


for maintenance while the turbine(s) are running. The PC basedoperator/maintenance interface contains no control or protection software; therefore,maintenance of this equipment does not jeopardize either the speed control or theoverspeed protection system.

When power is applied, the system initializes in manual control and in the trippedcondition. The system can be operated in manual control (L43MAN_A/B) orautomatic control (L43AUTO_A/B). The L prefix in these logic signals is used forall logic signals in the system.

The unit can be manually started from either a hardwired interface in the maincontrol room or an operator/maintenance interface PC located local or remote. Someinstallations have a technicians interface \module on the control cabinet door that isused for tuning, trending, or editing application software, but not for operatorcontrol.

A contact from the main control room provides a momentary closed logic to thecontrol system that selects manual control. Raise and lower contacts can now begiven to the control system. Independent raise/lower slow contacts will initiate acontrol response at the manual slow ramp rate (KTNHR_RMS) and raise/lower fastcontacts will initiate a control response at the manual fast ramp rate(KTNHR_RMF). A K prefix is used for all tuning constant signal names. Constantscan be changed while the unit is running. The unit will continue to ramp at theserates as long as these contacts are closed. Contact outputs are provided to the maincontrol room for indication of the control mode and the current running speed.

Note Operators and maintenance personnel are provided speed indication in rpm forconvenience, but the control system is calibrated in percent to facilitate fast andaccurate calibration. A single control constant (KTNH_GAIN_A/B) is used to scalefrom rpm to percent speed.

Manual control from the operator/maintenance interface PC works in a similarmanner. Operator commands are initiated with a mouse or trackball. Selection ofcontrol modes must be followed by a confirming EXECUTE command to prevent anaccidental change in control modes. Raise/lower commands are initiated from amouse or trackball, which is designed to initiate a single, incremental change inspeed with each click to eliminate any significant, accidental speed changes. Araise/lower slow click will initiate a 1-2 rpm change, and a raise/lower fast click willinitiate about a 20 rpm change (adjustable). Significant speed changes can be madeby typing in the desired speed such as 5,000, which will cause the turbine to ramp to5,000 rpm. The control will not ramp to a speed setpoint that is above the speedgovernor limits.

While in manual control, a momentary automatic start command can be given toinitiate an automatic start sequence (L43ASTART_A/B). The speed will increase atthe manual fast ramp rate (K14TNHR_RMF_A/B) to a predefined threshold(K14H_ASTRT_A/B). Permissives for the start sequence are that the turbine is reset,in manual control, and that the speed is below the threshold limit. Once theautomatic start sequence is in progress, it can be stopped only by a manual orautomatic trip prior to reaching the speed limit. Any time the turbine trips, it can bereset while coasting down. This causes the speed reference to be preset slightly(about 100 rpm) below the current running speed. The adjustable offset(KTNH_POFF_A/B) eliminates overshoot due to the difference in speed between thetime that the reset command is given and the time that the system actually resets.

The operator should manually raise the turbine speed to match the speed reference ofthe feedwater control system prior to selecting automatic control. If the operator doesnot match speed, the control system will go into automatic control (L43AUTO_A/B).


If the speed is above the low speed stop (L14LS_A/B), the speed will automaticallyramp to match the feedwater control system reference at the manual slow ramp rate(K14TNHR_RMS_A/B). When a null is reached (K14HNULL_A/B), the ramp ratewill change to the auto ramp rate (KTNHR_RA_A/B).

Diagnostics continuously monitor the feedwater control system reference(PREF_A/B) to alarm if the reference is above the high limit, below the low limit orif the rate of change is excessive. An excessive rate of change, will alarm and causean automatic transfer to manual control, but out of limits diagnostics will alarm only.A gross failure in the feedwater reference, such as disconnecting the field wire, willresult in a transfer to manual control. Implementation of this function should accountfor the maximum normal rate of change of the reference from the feedwater controlsystem.

Any control location can transfer the system from automatic to manual control withno change in the speed reference. If the main control room originally selectsautomatic control through contact inputs, then only the main control room caninitiate a transfer to manual control. If automatic control is selected from theoperator/maintenance interface PC, then any control location can transfer the systemback to manual control.

The speed control algorithm (XTNCB03) is configured to run as an isochronousgovernor with no speed droop. The speed feedback (TNH_A/B) is subtracted fromthe speed reference (TNR_A/B), which results in the speed error (TNHE_A/B). Ifthe deviation between the reference and the feedback exceeds a predefined limit(KTNHDEV_A/B), then an alarm message is generated. This proportional plusintegral control is calibrated by the following tuning constants:

• KTNE_G_A/B Speed Error Gain Constant (%/%)

• KTNE_I_TC_A/B Integrator Time Constant (s)

• KTNE_DB_A/B Speed Error Deadband Hold Constant (%)

The final output of the speed control algorithm is the total power reference(TPWR_A/B), which provides a reference to the valve control.

Valve ControlThe following control description assumes a GE 200# oil gear system.

The total power reference from the speed control algorithm determines the valvestroke reference (V1_STROKE_A/B). This calculation is performed by a LinearInterpolator algorithm (ALIP00), which characterizes the flow versus the strokerelationship with 10 points using constants (KV1_FLOW#_A/B) and(KV1_STR#_A/B). Normally, the valve stroke reference and the output to the valveregulator (V1_OUT_A/B) are the same unless the valve is being calibrated.

Calibration is permitted if the turbine is tripped (L4_A/B = 0) and the speed is zero(L14HR_A/B = 1). Since there are two turbines, each V1 actuator is calibratedindependent of the other turbine�s V1 actuator including calibrating one turbine,which is stopped while the other turbine is running. Selection of the turbine-specificcalibration data is performed by selecting the appropriate turbine valve on thedisplay. Each half of this display will initiate a unique number to be generated in thedata base for (JADJ), which will force the output to the valve regulator(V1_OUT_A/B) to track the manual V1 calibration reference (GSADJ) instead of thenormal valve stroke reference (V1_STROKE_A/B).


All of the application software that has been discussed so far has been executed inthe main processor card (UCV_) and is completely configurable. Actual, closed-loopregulation of the V1 valve is performed in a dedicated algorithm in the servo card(VSVO) and run at 5 ms. The error between the output to the valve regulator(V1_OUT_A/B) and the position feedback from the main cylinder (the outer loop) iscalculated, and that error is compared to the pilot valve position (the inner loop). Apair of redundant LVDRs is used to provide feedback for the main cylinder positionand the pilot valve position with a high-select function for each LVDR pair.

Linear InterpolatorV1_FLO_R

Flow Reference

KV1_FLOW0 Args

InputV1_STROKE

A=BA

B

F(x)

x "10"

KV1_STR0

Size

Function

Out

Stroke Reference Servo Valve Output

SelectID Code

JADJID #

Enable

Input

Turbine is reset

Output V1_OUT

GSADJ Calibrate reference

K33V1_TRIP

L14HR L3ADJCalibratePermissive

Forcing InProgress

L43MAINT

Alarm - Maintenanceforcing mode enabled

JADJ - Valve calibration selectionfrom maintenance display

L43ADJ

ARAMPA>X

OutA<X

GSADJ_REF

Up

DownInput

Rate

Reset

KGSADJ_RR

Not used

Valve Regulator - Type 2

Bias - cylinder feedback

Gain - cylinder feedback

Reference

LVDR #1

Offset #1

Gain #1

LVDR #2

Offset #2

Gain #2

LVDR #1

Offset #1

Gain #1

F( )+

+

+

-

-

-

x

x

x

+-

x ++

Cylinder position

Cylinder LVDR #1 position

V1_POS

D/AConverter

A/DConverter

A/DConverter

A/DConverter

Servo Reference

Main cylinder positionfeedback inputs fromLVDRs. The secondLVDR is optional forredundancy.

Turbine stopped

L4 Turbine is reset

L14HP At overspeed OR

Copy

Enable

"0"A=B

A

BKJADJV1

JADJL83JADJ_V1

L83JADJ_V2

L83JADJ_V3AND

V1 In Calibrate Mode

Calibrate Mode Off

+-

x ++

Gain - pilot feedback

Cylinder LVDR #2 position

F( )

LVDR #2

Offset #2

Gain #2

+

-xA/D

Converter

Pilot position

Pilot LVDR #1 position

Pilot LVDR #2 position

+- x-

+-+

Lag1/(1+Ts)

High limit

Converg. gain

Conv. ref.

Lag TC

Low limit

IntegratorOutput

SVR_INTGRT_1Copy

SVR_CONVG_1 -TMR systems onlyConverge outputs of <R><S><T> to median

Pilot valve positionfeedback inputs fromLVDRs. The secondLVDR is optional forredundancy.

L83JADJ_OFF

No valve incalibration mode

Type Position Detection 2D First assigned LVDR 2E Max of (2) assigned LVDRs

V1_POS1

V1_POS2

V1_PIL

V1_PIL1

V1_PIL2

GE 200# Oil Gear System Valve Control

Trip ProtectionAll trip protection is imbedded in the triple redundant control modules. The tripsoftware is contained near the end of software segments SEQ_T2A and SEQ_T2B.All trip logic is OR�ed in software rung L4T_A/B and its two auxiliariesL4TX1_A/B and L4TX2_A/B. A logic 1 indicates a trip condition.

For Retrofit ApplicationsThe final logic state which determines whether the Mark VI will tell the trip solenoidto trip is L20PTR1_A or L20PTR2_B. This logic drives output ports in the threeVCRC cards which simultaneously drive relay drivers on the TRLY TerminalBoards. One relay on each of two TRLY�s is driven by the L20PTR#_ logic. Theserelays are energized when the turbine is running, and diagnostics monitor the currentthrough the relay coils to verify that the relays have actually energized. A single


normally open contact from each relay drives an interposing HGA relay with a highcontact output rating for interface to the trip solenoid. The HGA relays are mountedin the turbine control cabinet, and the 125 V dc coils are suppressed. Both HGArelays are energized when the turbine is running, and a contact from each relay is fedback to provide confirmation that the relays have energized. Normally-closedcontacts from the HGA relays are connected in series on the high side of the SV12solenoid circuit to energize the solenoid if both HGA relays simultaneously de-energize. Connecting both relay contacts on the high side of the solenoid circuitallows a lamp circuit to be used to verify the solenoid coil condition since it isenergize to trip.

For Triple Redundant ApplicationsThese applications have three control modules and three sections of the emergencyoverspeed module driving three hydraulic trip solenoids that are de-energized to trip.Each solenoid is connected between the terminal board from the control moduleswhich supplies �125 V dc and the terminal board from the emergency overspeedmodule which supplies +125 V dc from separately fused feeders. Diagnosticsmonitor a contact feedback from each relay each terminal board and the voltageacross each solenoid. A trip from one control module will de-energize one tripsolenoid and not trip the turbine. A trip from two or three control modules will tripthe turbine. The solenoids can be tested on-line by tripping one solenoid at a time.

Contact Input TripsAll contact inputs are dry contacts that close if an alarm or trip condition occurs.Contact inputs are connected in a 125 V dc circuit that is powered from the Mark VI.Each contact input terminates on a single TBCI terminal board where it is internallyfanned to three separate VCRC cards in the control modules. Each card opticallyisolates each input and provides a 1 ms SOE time stamp.

Software in the control modules can be categorized as operating system software andapplication software. The operating system reads each contact input and exchangesthe data between the VCMI cards in each control module. Each VCMI calculates thelogical vote and passes the voted data to the application software to execute. As anexample, if the pump bearing oil pressure is low, the field contact closes whichresults in a logic 1 condition in all three modules. If an internal electronic componentfails in the <R> module, <R> could see a logic 0 when <S> and <T> see a logic 1.Since the data is exchanged between the VCMI�s, they will alarm a failure in thecontact input circuit in <R> while the correct logic 1 state is passed from <R>'soperating system software to its application software. Diagnostics are able todistinguish an internal logic failure from an external failure because a single fieldcontact that terminates on a single screw can produce a logic discrepancy only for aninternal failure.

External failures in the field switches and wiring are more likely to occur thaninternal failures; therefore, three field switches are normally used in trip circuits suchas the pump bearing oil pressure. One switch is set to close when the pressure dropsbelow the alarm level. Two additional switches are set at the trip level. Applicationsoftware will trip the unit if it sees two of these switches close. Diagnostics willalarm if there is a discrepancy between the three field switches or if a trip switchcloses prior to the alarm switch closing.


Typical redundant trip switches include:

• Header Pressure Trip

• Turbine Bearing Oil Pressure Low Trip

• Pump Bearing Oil Pressure Low Trip

• Vacuum Low Trip

• Pump Suction Low Trip

Overspeed ProtectionThere are two levels of overspeed protection excluding the normal speed controlfunction of the governor. The speed control algorithm (XTNCB03) will initiate anoverspeed trip command if the speed (TNH_A/B) reaches the primary overspeedlimit (KTNHOS_A/B). The mechanical overspeed bolt provides another level ofoverspeed trip protection. If the turbine does not have a mechanical overspeed bolt,then a triple redundant emergency overspeed (EOS) Module is used for each turbineto replace the mechanical overspeed bolt. In some retrofit applications, there is amechanical overspeed bolt and the EOS module as a customer requirement.

A test of the primary overspeed trip system can be initiated from the overspeed testdisplay when the pump is uncoupled and reset, and the speed is above the low speedstop and below the high-speed stop.

Note The control system has no automatic way of knowing whether the pump iscoupled or not coupled. Pushing the test button on the display will cause the speedreference to be ramped to 1% (KOS_BIAS_A/B) above the Primary overspeed tripsetpoint (KTNHOS_A/B) at a ramp rate determined by time constant(KTNHR_TC_A/B).


J2

<P> Protection Module (EOS) - Section X

JR1

<R><S>

<T>Turbine CardIS200VTUR

ProcessorCardIS200UCV_

Pr/D

Shown for <R>

Same for <S>

Same for <T>

#1 PrimaryMagneticSpeed PU

FilterClamp

ACCoupling

Suppr.

FilterClamp

ACCoupling

Suppr.#2 PrimaryMagneticSpeed PU

FilterClamp

ACCoupling

Suppr.#3 PrimaryMagneticSpeed PU

0 to 14 k Hz

f( )

JX5

Termination BoardIS200TTUR

#1 Emerg.MagneticSpeed PU

FilterClamp

ACCoupling

Suppr.

FilterClamp

ACCoupling

Suppr.#2 Emerg.MagneticSpeed PU

FilterClamp

ACCoupling

Suppr.#3 Emerg.MagneticSpeed PU

Termination BoardIS200TPRO

J5

Median Select& OS Algorithm Buffer

J4Shown for <R>

J4

J4

Same for <S>

Same for <T>

Termination BoardIS200TRPG1

JS1

JT1

Termination BoardIS200TREG

JX1

JY1

JZ1

<PDM>24 or 125vdc

J1

J5

JY5

JZ5

Pr/Df( ) OS Algorithm BufferJ3

Connectors atbottom of

VME racks

<PDM>125vdc

J7

<P> Protection Module (EOS) - Section Y

<P> Protection Module (EOS) - Section Z

Same for Section Y

Same for Section Z

JR5

JS5

JT5

IS200VPRO

IS200VPRO

IS200VPRO

J2

Power

Hydraulic Trip Solenoids+

-

-

<R> Commun.

Trip signal toservo TB

TSVO (JD1)

J1

41

42

33

34

25

26

31

32

37

38

43

44

4 Circuits

4 Circuits

4 Circuits

3 Circuits

3 Circuits

3 Circuits

Primary and Emergency Overspeed System

A test of the mechanical overspeed bolt can be initiated from the same display whenthe turbine is uncoupled and reset, and the speed is above the low speed stop andbelow the high speed stop. This will cause the primary overspeed trip setpoint(KTNHOS_A/B) to be automatically moved above the mechanical bolt setpoint(KTNHMOS_A/B), and the turbine will accelerate to the trip limit.

An EOS module monitors a separate set of three passive, magnetic speed sensorswhich are terminated on the TPRO terminal board and connected internally to thethree VPRO cards with independent power supplies, processors, and I/O. Eachsection monitors the speed and calculates:

• Excessive overspeed (L12H)

• Fast overspeed detection - interrupt driven every 8 pulses (L12H_TP0)

• Excessive rate of change ±100 %/s (L12H_TP2)

• Turbine below 10% speed (L14H_ZE)

• Turbine above adjustable setpoint (L14H_MN)

The EOS module will trip independent of the control modules, and diagnostic data iscommunicated back to the VCMI cards in the control modules for alarming and/orcross-tripping. For example, the control modules expect to see a 10% speed signal(L14H_ZE) from the EOS module when there is a 10% signal from the primaryspeed sensors. If this does not occur, the turbine trips.


A test of the EOS module can be initiated from the overspeed test display when theturbine is uncoupled and reset, and the speed is above the low speed stop and belowthe high-speed stop. This will cause the EOS trip setpoint to be reduced below theprimary overspeed trip setpoint (KTNHOS_A/B), and the turbine will accelerate tothe trip limit.

Thrust Wear Protection

ProcessorCardIS200UCV_

K39AAA active alarm AB

AB

AB

AB

A>=B

A<=B

A>=B

A<=B

K39AIA inactive alarm

K39AAT active trip

K39AIT inactive trip

OR

ORL39AF1 probe fault

Trip L39AXT1

Alarm L39AXA1XAXPO01 - Axial Position Monitor

AXIAL1 input

L39AF2 L39AXT2

AXIAL2 L39AXA2

AXIAL3 L39AXA3

L39AF3 L39AXT3

Same as above for thrust input #2

Same as above for thrust input #3

L39AF1 Probe #1 Fault Alarm - 1 sec TDL39AF2 Probe #2 Fault Alarm - 1 sec TDL39AF3 Probe #3 Fault Alarm - 1 sec TD

2/3 TL39AF2L39AF1

L39AF3

L39AXFT

1 sec

2/3 ProbeFault Trip 2/3 T

L39AXT2L39AXT1

L39AXT3

L39AXT

1 sec

2/3 Probes AtTrip Level

OR TL39AXA2L39AXA1

L39AXA3

L39AXA

1 sec

Any Probe AtAlarm Level

<R><S>

<T>ProximitorCardIS200VVIB

Termination BoardIS200TVIB

JR1

Connectors atbottom of

VME racks

A/D

Shown for <R>

Same for <S>

Same for <T>

CL

NoiseSuppression

CL

NoiseSuppression

-24vdc

-24vdc

-28vdc

Probe Proximitor CL

NoiseSuppressionRange = -0.5 to -20 vdc

Accuracy = 1% of full scaleResolution = 14 Bits

-24vdc

Not Used

Not Used

Not Used

Not Used

J3/4

JS1

JT1

J3/4

J3/4

Buffered OuputsTo Bently Nevada

3500 Monitor

Input Terminations

JC1

JD1

JC1: Circuits 9-12 PositionJD1: Circuits 13, 14 KP

Sampling TypeA/D (16 bit)

Probe Proximitor

Probe Proximitor

Three redundant axial position probes are used to monitor the turbine thrust and themedian value is displayed on the main display. Axial positions for each probe aredisplayed in bar chart format on the proximitor display. Positions are displayed ingreen if the vibration is below the high alarm level and no fault is detected. Anabnormal condition will cause the specific bar to turn red.

A redundant −23 V dc source is provided from the VVIB cards in the controlmodules for the proximitors and the resultant dc input is monitored for the axialposition. An alarm will occur if the position exceeds the alarm limit on any probe inthe active (K39AAA_A/B) direction or in the inactive (K39AIA_A/B) direction. Atrip will occur if the position exceeds the trip limit on two out of three probes in theactive (K39AAT_A/B) direction or in the inactive (K39AIT_A/B) direction. Thediagnostics will alarm a fault condition if they detect a fault on any probe, and anautomatic trip will occur if a fault is detected on two out of three probes. The faultdetection will automatically inhibit a false trip logic in the algorithm. The pump axialposition is monitored with a single probe to alarm an excessive thrust level in the


active (K39AAA_P_A/B) direction or in the inactive (K39AIA_P_A/B) direction,and diagnostics will alarm a probe fault.

Vibration ProtectionThe VVIB cards in the control modules directly monitor Bently Nevada vibrationsensors. An X and Y probe is used to monitor vibration on the HP and LP turbinebearings and the inboard and outboard pump bearings. The main display shows aturbine-pump diagram with a bearing vibration level determined by the highestvibration level of each X/Y probe pair. Vibration levels for each probe are displayedin bar chart format on the proximitor display. Vibration levels are displayed in greenif the vibration is below the high alarm level and no fault is detected. An abnormalcondition will cause the specific bar to turn red.

The ac component of the proximitor input is used to determine the vibrationmagnitude, and the dc component is used to monitor the gap for fault detection. Ahigh or high-high alarm will occur if excessive vibration is detected on either probe.A fault alarm will occur if a fault is detected on any probe, and it will inhibit a falsealarm message of a high vibration level. Unique control constants are used to set thehigh (K39VA#_A/B) and high-high (K39VT#_A/B) alarm levels for each probe. Allturbine trips for the vibration system must be manually initiated.

Vibration data available in the data base and from buffered BNC connectors on theTVIB terminal boards includes:

• The unfiltered Direct Magnitude of the vibration input in (mils)

• The 1X Magnitude (mils) and Phase Angle (degrees)

• The 2X Magnitude (mils)

• The dc gap voltage (mils)

Eccentricity MonitorEccentricity is measured while the turbine is on turning gear. The algorithmcontinuously monitors the gap between the probe and the shaft for the time(K2REV_A/B) required for the shaft to make one revolution. The maximumdeviation in the gap per revolution is shown on the proximitor display bar chart. Analarm is initiated if the deviation exceeds the high alarm limit (K30EC_H_A/B) orthe high-high alarm limit (K30EC_HH_A/B). A probe fault will cause a separatefault alarm, and it will inhibit a false alarm message for a high eccentricity level.manual action is required to trip the turbine for a high or high-high eccentricitycondition.


Packaging

EOS Module3 Independent Sections

3 Control Modules

Mark VI Electronics

The standard turbine control enclosure consists of a NEMA 1, convection cooledcabinet with front access and top or bottom cable entrances. It is rated for continuousoperation in a 0 to 45 °C ambient and operation up to 50 °C during maintenanceperiods; however, it is recommended that this microprocessor based product belocated in an air-conditioned environment. Other types of enclosures are availablewith built-in cooling systems and purification systems as required for the application.


There are various types of cabinet arrangements. The most typical arrangementconsists of a cabinet containing the three control modules and a separate cabinetcontaining the terminal boards and power converters/distribution. All of theelectronics are mounted on the back base (nothing on the side-walls). These cabinetsare relatively shallow at 23.6 in. (600 mm) deep and can be mounted either side-by-side or back-to-back. They are used on most new unit applications and are alsoavailable for retrofit applications if sufficient space is available. A more compactcabinet is frequently used for retrofit applications and is deeper and narrower. This isaccomplished by mounting the terminal boards on the side walls.

Typical Cabinet Specifications

English Units Metric UnitsDimensions- Control Cabinet- Termin. Cabinet- Retrofit Cabinet

63.0 in. W x 86.6 in. H x 23.6 in. D63.0 in. W x 86.6 in. H x 23.6 in. D53.1 in. W x 86.6 in. H x 35.4 in. D

1,600 mmW x 2,200 mmH x 600 mmD1,600 mmW x 2,200 mmH x 600 mmD1,350 mmW x 2,200 mmH x 900 mmD

Weight per cabinet 1,000 lbs. (typical) 453.6 kgs. (typical)Temp. - Operate +32 to +113 °F 0 to +45 °C - Storage -40 to +158 °F -40 to +70 °CHeat 1,000 Watts (typical) 1,000 Watts (typical)Humidity 5 to 95% non-condensing 5 to 95% non-condensing

PowerThe turbine control is normally powered from redundant 115/230 V ac powersources. Provision for a floating 125 V dc source is also available. The ac powerconverters include an isolation transformer and a full wave rectifier to produce a 125V dc output that is high-selected. This redundant, internal 125 V dc bus is isolatedand fed to the various module power supplies through the power distribution module.Separate 125 V dc feeders are used to distribute the power to each contact input andrelay output terminal board. Each solenoid circuit has additional fuses on the positiveand negative sides. Diagnostics monitor each voltage source and each feederincluding the fuses in each solenoid circuit on the relay terminal board. Interposingrelays are used for retrofit applications with energize-to-trip solenoids.

Control Cabinet PowerSteady-State Voltage Frequency Load Comments120 V ac (108 to 132 V ac) 47 � 53 Hz

57 � 63 Hz6 A rms Harmonic distortion < 7%

240 V ac (216 to 264 V ac) 47 � 53 Hz57 � 63 Hz

3 A rms Harmonic distortion < 7 %

125 V dc (100 to 145 V dc) 6 A dc Ripple <= 5%

* Power source load estimate does not include the load of external solenoids.


Operator ScreensThe operator/maintenance interface is commonly referred to as the HMI. It is a PCwith a GE CIMPLICITY graphics user interface, a Microsoft Windows NToperating system, a Control System Toolbox with editors for the application softwareand unit specific screens. It can be applied as:

• The primary operator interface for one or multiple units including the mainreheat steam turbine and its generator excitation system

• A backup operator interface to the plant DCS operator interface

• A gateway for communication links to other control systems

• A permanent or temporary maintenance station

• An engineer�s workstation

All control and protection is resident in the turbine control, which allows the HMI tobe a non-essential component of the control system. It can be reinitialized orreplaced with the turbine running with no impact on the control system. The HMIcommunicates with the processor card in the turbine control through the Ethernetbased UDH.

Feed pump turbine control screens show a diagram of the turbine with the primarycontrol parameters. When two turbines are controlled from a single triple redundantcontrol system, the screens show turbine A on the left and turbine B on the right withidentical graphics. The basic diagram is repeated on most of the screens to enableoperators to maintain a visual picture of the turbine�s performance while changingscreens. All screens have a menu on the right-hand side of the display which has ahierarchy of an overview screen (for a multiple unit site), unit selection (feed pumpturbine, main unit, generator excitation), and a menu of all of the feed pump turbineoperator screens.

Typical feed pump turbine screens include:

• BFPT Main Display (Primary Operator Control)

• Offline Tests

• Online Tests

• Valve Calibration

• Proximitors for Turbine A

• Proximitors for Turbine B


Feed Pump Turbine Graphics

The primary screen in the system is the Main screen. This single display can be usedfor auto/manual control selection, raise/lower, fast/slow commands, tripping,accessing alarm messages, and monitoring control parameters from both turbines.

All operator commands can be given through momentary pushbutton commands onthe screen. The command is sent to the Mark VI control where the applicationsoftware initiates the requested action assuming that the appropriate permissives aresatisfied. A response to the command can be observed within one second if it doesnot involve subsequent system time delays. As an example, if a Select Autocommand is given. A small pop-up window will appear above the Select Auto buttonfor the operator to verify that he/she really intends to select Automatic Control of theturbine. Upon verification, the application software checks the permissives andinitiates a transfer to automatic control that results in a Automatic Control message.

If the turbine was not ready for automatic control, then an alarm message wouldappear in the bottom left-hand corner of the display identifying the reason.

Note The purpose of the alarm queue is to identify any abnormal condition. Alarmmessages are displayed with 20 ms resolution and SOE are displayed with 1 msresolution. An alarm buffer is included with 10 MB or 30 days of storage.


The Trip Status display provides a graphical representation and status of all potentialturbine trips. This graphic also relates to the functional organization of theapplication software. If there are latched trips, then the operator must select theMaster Reset button. This references another screen to remind the operator of theneed to investigate and correct the reason for the latched trip prior to issuing aMaster Reset. A trip history log is included for all of the key control parameters andalarms scanned at 20 ms for 1 minute and at 1 s for 10 hours for each of 10 trips.

gGE Industrial Systems

General Electric Company1501 Roanoke Blvd.Salem, VA 24153-6492 USA

Issue date: 2000-08-31 2000 by General Electric Company, USA.All rights reserved.

Documents

GE Industrial Systems