background image

- Vdc

Control, Protection, Monitoring

Controller      R

Controller     S

Controller     T

2/3 Relay

Voting

Backup Prot.  X

Backup Prot.  Y

Backup          Z 
Protection

Servo

Drivers

+ Vdc

2/3 Relay

Voting

Speed Difference Detection

Watchdog Diagnostics

Cross-tripping

3 IONETs

Overspeed with Accel/Decel

Backup Synch Check

Manual Trip

Hydraulic Trip 
Solenoids

Control 
Valves

MED

R
S
T

MED

X
Y
Z

AND

Run

MED

R
S
T

MED

X
Y
Z

OR

Trip

Protection Redundancy, Triple Redundant Systems

A key tripping reliability feature is cross-tripping. The primary and backup systems initiate a trip independently, but can also
initiate a cross-trip for additional tripping redundancy. For example, a trip that originates in the backup protection can be sent
to the primary protection to close the control valves and de-energize the trip solenoids from the primary side. Another
example, the backup protection monitors communications from each controller, so it can be configured to initiate a trip on
behalf of the controllers.

Functionality for the backup protection system is application-specific and subject to the safety requirements dictated by code
and/or GE design practices for specific turbine types. In general, it complies with most industry standards. It is separate and
independent from the primary protection, with more functionality than required by most codes. As an example,
ANSI/API-670 requirements for overspeed protection are written for an (one) independent, triple redundant system. The
standard GE overspeed system for a heavy-duty gas turbine or a combined-cycle steam turbine consists of two triple
redundant protection systems with cross-tripping.

16

GEI-100728A

Mark VIe Controls System Redundancy Options

Public Information

Содержание Mark VIe

Страница 1: ...nt contains non sensitive information approved for public disclosure GE may have patents or pending patent applications covering subject matter in this document The furnishing of this document does no...

Страница 2: ...Controller 7 5 I O Network Redundancy 7 6 I O Redundancy 8 6 1 Dual Redundancy 8 6 2 Triple Modular Redundancy 11 7 Tripping Reliability 15 8 Digital Bus Reliability 17 8 1 FOUNDATION Fieldbus 17 8 2...

Страница 3: ...ting the process Field components for example sensors actuators and wiring cause over half of forced outages Therefore redundancy of field components is an important consideration in the overall contr...

Страница 4: ...one component is out voted by the other two In the case of three lube oil pressure switches the protective system performs a simple logical vote with no need to predict in advance a probable failure m...

Страница 5: ...ing Blocks Controller 3 IONET Ports 2 Control Network Ports 1 COM Port IONET Switch I O Module I O Pack Local Processor Data Acquisition Terminal Block Typical Mark VIe Architecture Instruction Guide...

Страница 6: ...ther the controllers are redundant or non redundant But they can be supplied in redundant pairs too if required Additional redundancy options are available Internal Power Converters Create 28V dc for...

Страница 7: ...board rack or mounted inside the rack with communication on the backplane The I O network consists of active electronics at both ends and multiple failure modes so its redundancy is just as important...

Страница 8: ...at the I O pack level Therefore replacement of I O has minimal impact on monitoring and control of the overall control system An extension of this is to add a third sensor whose value can be voted in...

Страница 9: ...ovides recovery data 4 Receives external commands 5 Creates process alarms Data outputs from dual redundant controllers are normally implemented with each controller sending its signal to its switch a...

Страница 10: ...ollers IONET switches and Ethernet ports on a common I O pack which controls a relay driver and a relay Level 2 also provides dual redundant controllers and IONET switches but extends the redundancy t...

Страница 11: ...ed or transmitted individually Fanned inputs are transmitted on the IONET with three I O packs on the I O module Therefore a failure of an I O pack does not inhibit any controller from seeing all of t...

Страница 12: ...les 3 Less IONET switches Non critical data that is being used for non essential monitoring is usually implemented without redundancy Redundant and non redundant I O coexists in most control systems T...

Страница 13: ...nt sharing circuit Analog Voting occurs with a3 coil servo Extended Voting at Field Device Example 3 Coil Servo Valve Actuator Typical nuclear configuration Valve Regulator Valve Ref Valve Regulator V...

Страница 14: ...Requirements for no single point failures must be evaluated on a case by case basis to determine the best way to approach this from the system level The preceding figure displays a variation of outpu...

Страница 15: ...responding I O control protect and monitor the turbine Primary protection includes a full set of all trip functions and backup protection includes a small subset of the protection functions to backup...

Страница 16: ...control valves and de energize the trip solenoids from the primary side Another example the backup protection monitors communications from each controller so it can be configured to initiate a trip o...

Страница 17: ...the designated controller and a secondary controller Therefore the primary linking device is the one connected to the primary controller Less common are applications with a single controller and redun...

Страница 18: ...al Controllers Supplies Switches Simplex Non redundant Dual with Redundant I O Full Triple Redundant Dual Redundant Triple Relative Contributions to Reliability and MTBFO Adding redundancy to the elec...

Страница 19: ...Public Information...

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