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Turbine Control Systems with Electric and SAFECLOZE Actuators p1Lovejoy Controls Corporation, Waukesha, Wisconsin, USA07-06

About Lovejoy Controls Corporation

LCC is an independent, privately ownedmanufacturer of turbine controls andinstruments located in Waukesha,Wisconsin. Primary LCC products of it's15,000 ft manufacturing facility are2

modern digital governor systems, steam valve actuator retrofit packages,redundant overspeed trip systems for fossil power, nuclear power, and navalmilitary markets. LCC also provides engineering support and turn keyservices for a wide range of rotating equipment repair and diagnosticevaluation. LCC has been in continuous business since 1977.

Contact Info:

Address Lovejoy Controls Corporation1301 Sentry Drive, Waukesha, WI 53186

Phone 262 542 9061Fax 262 542 7139Web http://www.lovejoycontrols.comEmail [email protected]

Information Bulletin No. 07-06


Turbine Control System Retrofits withElectric and SafeCloze Actuators

Issue July 2007


INDEX

Section Topic Page

1.0 Governor Products Overview 4

1.1 Series 2 51.2 200 Series 71.3 TEG-5 91.4 Dedicated Operator Control Stations 141.5 DCS Interface Control 15

2.0 Electric Actuators as Valve Operators 16

2.1 Stand Alone Electric Actuator Applications 172.2 LCC SAFECLOZE Fail Safe Actuators 19

3.0 Application Recommendations 22 3.1 Governor Recommendations 22

3.2 Electric Actuator Recommendations 23

4.0 Other LCC Products 25


1.0 Governor Products OverviewNOTE: The use of LCC turbine governors with LCC valve operating

systems is not mandated. Units with recent digital governorupgrades can be retrofit with LCC electric or hybrid actuatorpackages operating from third party systems. LCC desires it'sclients to benefit from available technology improvements butdoes not believe that wholesale equipment changes are alwaysnecessary. If you have a recent vintage and successfullyoperating GE Mark V or VI, ABB P14, Woodward 505, WoodGroup, ICS Triplex, InvenSys 310, Alstom Microgovernor orP320, or other solid digital system. LCC can provide a cleanadaptation to electric actuator control.

LCC manufactures three platforms of steam turbine governors for turbinecontrols upgrades. The platforms features are overlapping and in manyapplications two systems will fit with particular options and preferences bestguiding the selection.

The LCC Series 2 is the most economical solution where the standardcapabilities meet the control requirements.

The LCC 200 Series is more versatile, employing a modular architecturewith fully redundant networked LCCNET Modules, each proven in hundredsof unit operating years to date. 200 Series Governors can control anysteam turbine on earth in simplex, duplex, or 2-of-3 redundantconfigurations.

The LCC TEG-5 Series is a compact, integrated digital governor and electricactuator servo drive for nuclear safety related turbine applications such asAuxiliary Feedwater, RICSI, HPSI.

All of LCC's governor platforms meet speed loop closure criteria for the mostdemanding of turbine control applications.


1.1 Series 2Series 2 is a very compact, single 19"-rack fit package (10" height) thatincludes required electronics to operate most small turbines. One completerack-mount case includes:

? Simplex Turbine Governor? Operator Control Station Port? DCS Information/Control Port? Electric/Hybrid Actuator Position Demand Network (ValveNet)? Redundant Power Supplies with Auctioning & Monitoring

Series 2Front Panel View

Series 2Rear Panel View


Series 2 may operate multiple governor and throttle valve turbines and iscompatible with all operator control station and DCS control options.

Series 2 may install in an existing plant control cabinet or LCC may providea floor or wall mount enclosure.

Series 2 operates on redundant (2) magnetic speed probes usually locatedin proximity to an existing turbine speed wheel or turning gear.

Series 2BlockDiagram


1.2 200 SeriesThe basis of the 200 Series platform is the dual LCCNET communicationsnetwork which distributes control tasks between independent control andinformation units termed LCCNET Modules. By selective inclusion of specificLCCNET Modules a system is built to exacting feature requirements with thedesired level of redundant backup.

200Series Photos

200SeriesGraphics


A short list of LCCNET Modules includes:

? Governors...? Fossil BFPT Once-Thru Boiler Specific? Fossil BFPT Drum Boiler Specific? Nuclear BWR RFPT Specific? Nuclear PWR SGFPT Specific? Generation Main Unit, Governor Valves Only Specific? Generation Main Unit, Governor & Interceptor Specific? Generation Main Unit, Governor & Extraction Specific

? Valve Controllers...? All Electric Actuators? Hybrid Electric Actuators? EHC

? Data Interfaces...? Plant Computer? Remote Dispatch (AGC)? Operator Control Station MMI? DCS Links? Analog Signal? Digital Logic

... and Many More.

Because of the distributed, modular design, LCC's 200-Series may alsoincorporate additional instrumentation functions of:

? Turbine Supervisory Instruments? Torsional Vibration Monitor? Custom Instrumentation Monitoring


1.3 TEG-5

1.3.1 Electronic Governor, Electric ActuatorSolution

The LCC TEG-5 provides full turbine control to Tech Specparameters without the use or need of the troublesomeTerry turbine lube oil system. Redundant 115 VAC feedspower the governor/servo drive and remote operatorstation. The Digital Governor, Servo Drive, PowerSupplies, and all communications electronics is packagedin a single stainless steel enclosure.

1.3.2 Parallel Application

The TEG-5 was designed on the same platform as LCC'sSteam Generator Feedpump Turbine Governor system forlarge naval vessels. This production guarantees long termsupport and renewal parts availability missing in "warmover commercial" qualifications and adds the advantage ofmilitary specification testing of EMI/RFI, shock, andvibration far beyond typical governor standards.Sharing the same Bill of Materials and differing only inapplication firmware, the units have been qualified to:

MIL-STD-461 E: EMI/RFI Source & Susceptibility MIL-S-167-1 Vibration, Environmental & Internally Excited MIL-S-901D Shock Test, High Impact

1.3.3 Electric Actuator Direct Valve Stem DriveFor PWR Auxiliary FPTs the actuator is mounted on a spool piece which boltsto the governor valve bonnet flange, providing direct valveactuation which eliminates linkages and valve stem side loads. Direct operation results in superb valve positioning and governorcontrol.


1.3.4 NOT Vapor Ware... In Current ProductionOver the years several vendors, including the currentTerry Turbine ownership, have advertised systems "indevelopment" or "proposed solutions". The TEG-5 is incurrent production and available for immediate orderssubject to EQ Specification.

1.3.5 Fail-In-Place Actuator with Manual DriveIn the event that all drive power is lost, the actuator retainssufficient back wind resistance to maintain its last operatedposition. Further, the de-powered actuator may be manuallypositioned by an external handle or drill driver or wrench

1.3.6 Remote Operator Station Replaces HICsA fully digital Remote Operator Station mounts in a 1/4-DIN cut outproviding operator command inputs for both operation and surveillancetesting. Communications between the station and governor is accomplishedvia existing analog two-conductor cable with an RS-485 link.


1.3.7 Fully Configurable to Plant OperationsThe existing turbine control methods can be exactly duplicated in the TEG-5, requiring no changes to operating and/or surveillance procedures. Theend result is a control system transparent to operators and familiar incontrol procedures.

1.3.8 Design and Manufacturing QualityAssurance

The full design and manufacturing of the TEG-5 wasperformed under Lovejoy Controls Corporation'sQuality Management System, conforming to 10-CFR50 Appendix B and successfully passing two auditsto NUPIC standards in 2005. Complete softwarecontrols, component traceability, and defectreporting procedures are in use.


1.3.9 Fully Integrated Governor and Servo DriveThe TEG-5 single electronics enclosure holds allturbine-local electronics, including both the DigitalGovernor and the AC Servo Drive which operates theElectric Actuator. The combination of these controlelements in a single EMI/RFI contained stainless steelenclosure eliminates costly field packaging of looseelectronic components as offered by competitivesystems.

1.3.10 Site Specific Parameters Entry with LaptopPC

Specific turbine speed ranges, start up ramp speeds, governor parametersand servo drive parameters may be entered using a laptop PC. Settings areheld in nonvolatile memory. Record files are created to maintain setuphistory.


1.3.11 Diagnostic Condition Monitoring ComputerLink

A Condition Monitoring output serial link is available for connection to aplant instrumentation monitoring computer. Data includes the electricactuator current draw which provides a good tracking indication of valvestem friction and actuator motor health.

1.3.12 LCC's Extensive Electric ActuatorInstallation Experience

LCC has more steam turbine governor valve controlexperience with servo controlled electric actuators thanany other manufacturer worldwide. LCC has successfulretrofits in operation on generation turbines, feedwaterpump turbines, and hydro turbine applications.


1.4 Dedicated Operator Control StationsFor many turbine control retrofits, a dedicated operator control station(OCS) is required for either primary operator input or as a backup to DCScontrol. Usually the available space on bench boards or control room panelsis very restricted. For these reasons LCC offers a compact (1/2-DIN size)OCS which requires only a 3 1/2" x 7" panel cut out yet provides fulloperator control and display features for both the Series 2 and 200 Seriessystems.

Operator Control Station Front View

LCC's OCS design features a 4 x 3 switch panel matrix of tactile, backlighted switches combined with an LCD viewing screen for datapresentations.

LCC also offers color graphics touch screens and LED-based hard paneldisplays when these MMI styles are preferred.


1.5 DCS Interface ControlWith the popularity of distributed control and "soft" control rooms of theDistributed Control System (DCS) it is advantageous to bring as many plantsystems within the "loop" as possible.

While the DCS offers the benefit of centralized operator interaction andcombined systems condition monitoring, the process control loop closuretimes of most DCS exceed 0.15 second (150 milliseconds) and do not meetthe performance standard for turbine speed control.

NOTE: The speed loop closure time for the LCC Series 2 and the 200Series governor platforms is less than 35 milliseconds, as is thevalue for most dedicated governor systems.

Although some DCS are too slow to perform the full governor function, theDCS's workstations can still be used to provide operator control input anddata display. A straight forward ModBus RTU serial link between thesystems provides the data gateway.

LCC supports DCS workstation interfacing by supplying suggested controlscreen formats and data set protocol.

In applications where the DCS meets loop closure criteria, LCC can supportsoftware and hardware development to bring the turbine governor controlfunctions into the DCS.


2.0 Electric Actuators as Valve OperatorsThere are several steam turbine valve types, each with specific actuatorperformance and emergency shut down (trip) requirements. No singleactuator design is acceptable for all steam turbine valve types.

Electric Actuators use direct drive AC motors operating roller screwassemblies to produce linear motion. By "direct drive" we mean that eachincremental rotation of the motor results in a corresponding motion of theshaft at a ratio established by the roller screw lead or pitch. The directdrive action enables unprecedented control accuracy and solves the mostdifficult of valve positioning tasks.

Electric ActuatorDirect DriveRoller Screw

While the direct drive contributes greatly to control response, precision, andrepeatability it also presents a dilemma when applied to valve positioningrequiring rapid fail-safe closure (trip) action. By definition the Fail-SafeCondition of a direct drive electric actuator is the elimination of all powerfeed. By design specification of return spring force and actuator screwthread the actuator can be designed to slowly open, retain position, orslowly close upon power feed loss. By itself, however, the actuator cannotprovide a rapid fail safe closing action. LCC's SAFECLOZE actuator designsadd fail safe closure capability to electric actuator control.


2.1 Stand Alone Electric Actuator ApplicationsFor many turbine valve control applications the valve operator need nothave a rapid fail safe closing (trip) action. For these, the valve positioningsystem can be managed by a stand-alone electric actuator. Theseapplications include both fulcrum operated single and multiple valves andindividual steam line governor valves. The following figures illustratestand-alone electric actuator use where a fail safe trip capability is notneeded.

Electric actuator operatinga nuclear Main FeedwaterPump Turbine governorrack.


Electric actuator operating ageneration turbine governorvalve rack.


2.2 LCC SAFECLOZE Fail Safe ActuatorsFor valves requiring trip action LCC's (Patent Pending) SAFECLOZE actuatorsystem adds high speed fail-safe controlled valve closure in the form of anhydraulic position-latching cylinder physically mounted in series with theelectric actuator and having slightly greater stroke capability. TheSAFECLOZE valve actuator position is enabled by a self-contained hydraulicsreset cylinder which places the electric actuator in steam valve controlposition. If this pressure is removed, as occurs in a trip event, the electricactuator is re-located to a steam valve closed position independent of theimmediate roller screw action or relative stroke retraction. For reset of atripped SAFECLOZE valve the electric actuator is first automatically fullyextended (valve closed direction), then the hydraulic cylinder is retracted tothe reset position, with the reset pressure maintaining the full cylinderretraction. The steam valve can then be operated by the electric actuatorposition servo over the entire valve stroke range, yet be ready toimmediately trip to the closed position if necessary without electric actuatorinteraction.

The small self-contained hydraulics consists of a motor operated gear pumpwhich pressurizes the reset cylinder when the trip solenoid valves areseated in the reset position. Check valves maintain the reset cylinderpressure resulting in very low SAFECLOZE motor/pump operating duty andvery long service life.

Two typical LCC SAFECLOZE actuator applications are bonnet flangemounted individual valve actuation and fulcrum lift bar rack actuation. Each application is illustrated in the following figures.


SAFECLOZEoperatingsingle valveinternal view


SAFECLOZE operating fulcrum lift rack, internal detail view.


3.0 Application Recommendations

3.1 Governor RecommendationsAPPLICATION DCS

GOVERNORCODEDESIGN

DIGITALGOVERNORADAPTATION

LCC 200-SERIESGOVERNOR

LCC SERIES-2GOVERNOR

LCC TEG-5GOVERNOR

STEAM TURBINES

GENERATION< 5 CONTROLVALVES

YES YES USA, CANADA USA, CANADA,EUROPE

NO

GENERATION,>4 CONTROLVALVES

YES YES USA, CANADA NO NO

MAIN FEEDPUMP TURBINEDRIVE

YES YES USA, CANADA USA, CANADA,EUROPE

NO

AUXILIARYFEEDPUMPTURBINE DRIVE

NO NO NO NO YES

RICSI NO NO NO NO YES

HPSI NO NO NO NO YES

HYDRO TURBINES

WICKET GATE YES YES NO YES NO

KAPLAN YES YES NO YES NO


3.2 Electric Valve ActuatorRecommendations

The valve application table provides LCC's recommendations for retrofitactuator types for the most common steam turbine valve applications. Forspecial applications contact LCC.

TurbineType

ValveType

FailSafe?

ClosingTest?

Modulation Recommend

Fossil andNuclearMain FeedPump DriveTurbine

Stop Yes Yes No HydraulicCylinder withValve TestControl

Governor No No Yes Stand-AloneElectricActuator

SmallGenerationTurbine

Throttle Yes Yes Yes SAFECLOZEwith ValveTest


Mid SizeGenerationTurbine

Stop Yes Yes No HydraulicCylinder withValve TestControl

Throttle Yes Yes Yes SAFECLOZEwith ValveTest


Extraction Yes No Yes SAFECLOZE


TurbineType

ValveType

FailSafe?

ClosingTest?

Modulation Recommend

LargeGeneration

Main Stop Yes Yes No HydraulicCylinder with ValveTest

ReheatStop

Yes Yes No HydraulicCylinder with ValveTest

Governor Yes No Yes SAFECLOZE

Interceptor Yes No Yes SAFECLOZE

Extraction Yes No Yes SAFECLOZE


4.0 Other LCC ProductsLCC also manufactures and offers for sale:

? Full Turbine Supervisory Instruments, including:C Tuned Vibration Monitors (solve proximity probe

problems)C Thrust Position MonitorsC Sensor Alarm Monitors (RTD, thermocouple, analog)C Condenser Humidity MonitorsC Torsional Vibration MonitorsC Stress Corrosion Monitors

? Small and Micro Hydro Turbine Control:C GovernorsC SynchroscopesC Reverse Power Protection

? Naval and Marine:C Turbine GovernorsC Valve Control Systems

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