mark vi control

8/12/2019 Mark VI Control

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OVER VIEW OF GTG PLANT ANDCONTROL OF TURBINE



MAIN GB

ALTERNATOR

COMPRESSOR

TURBINE &COMBUSTOR

AUX GB STARTING DE

LUBE OIL PUMP



Gas Turbine principle

cooler

Heat rejected

Heat added

1

2

3

4

CompressorHeater

Turbine



Description

At point 1 cold gas enter a compressor to raise pressure

At point 2 the gas passes to the heater where

temperature of gas is raised

At point 3 the hot gas enters the turbine where itexpands to a lower pressure. The shaft work developed

by turbine flows in two direction.

At point 4 the exhaust gas flows to cooler where heat is

rejected and gas is restored in initial position



Brayton /Joule cycle

Volume

Pressure

1

2 3

4

Two reversible adiabatic or isentropic processes (1-2 and 3-4)

Two constant pressure processes (2-3 and 4-1)



Rankine cycle

Volume

Pressure

1

2 3

4

2-3 (Boiler)

3-4 (Turbine)

1-2 (BFP)

4-1 (Condenser)



Open cycle gas turbine

1

2

3

4

CompressorTurbine

Combustion chamber

Fuel

Air from atmosphere Product of combustion to atmosphere



Salient points

The source of energy is normally the combustion of fuel

in air

In closed cycle, gas turbine also product of combustion

of fuel and air may be passed through the heater

In open cycle cooler is not required

The heater is replaced by combustion chamber and fuel

is burnt directly in air stream



Open cycle gas turbine (With heater)

1

2

3

4

CompressorTurbine

Air from atmosphere

Product of combustion to atmosphere

Heat exchanger

Combustion chamber

Fuel



CONTROL SYSTEM

A control scheme of a gas turbine attempts to control the

following

SPEED

TEMPERATURE (COMBUSTOR OUTLET) LOAD

START UP CHARACTERISTICS

ACCELERATION CONTROL

Above characteristics are achieved by modulating fuel

flow. Control signal ultimately acts on the fuel valve



CONTROL SYSTEM

SPEED: The speed control loop controls the speed of

the turbine by controlling the fuel flow . Speed control

have speed sensing as input to the controller.

TEMPERATURE: Materials used in the hot gas path of

gas turbine are stretched much closer to their limits than

any other machine. The control system takes design

temperature of hot flue gas path material as set point.

LOAD: The control loop takes the MW as the set point.

The control loop also interferes when rate of loadingexceeds a certain point as turbine is loaded fast the

damage of the component may occur



CONTROL SYSTEM

START UP CHARCTERISTIC: The

control system brings the gas turbine from

zero speed to operating speed using

preset level of fuel flow through automaticsequencing of control signals to the

accessories, starting device and fuel

control system



CONTROL SYSTEM

ACCELERATION CONTROL: One critical

component of the turbine start sequence is

the acceleration to synchronous speed. A

design acceleration rate must bemaintained throughout start up to limit

stress on turbine parts.



MARK VI CONTROL SYSTEM

The main function of mark VI control

system are

Speed control during start up

Turbine load control during normal

operation on the grid

Protection against turbine over speed onloss of load

Automatic generator synchronization



MARK VI CONTROL SYSTEM

It runs on PC based work station using MSwindow client server architecture.

HMI provides operator display and control formark VI turbine controller

HMI contains a number of product feature Dynamic graphics

Alarm display

Process variable trending

Point control display (For maintenance)

HMI access security



COMMUNICATION

PLANT DATA HIGHWAY

UNIT DATA HIGHWAY

HMI SERVERNODE

I/O BOARD

UCVx CONTROLLER

DCS ETHERNET GSMDCS ETHERNET MODBUS



MARK VI TMR CONFIGURATION

Ethernet< R> CONTL MOD

< S> CONTL MOD

< T> CONTL MOD

X

Y

Z

< P> PROT MOD

TO DCS

Ethernet- IONet

Primary ControllerBackup Protection

To other GE

control sys

Software

Voting

PS

PS

PS



Primary Controller

Control

Protection

Monitoring<R>, <S>, <T> are Control processor

Backup Protection

Emergency over speed

Synchro check protection

<X>, <Y>, <Z> are back up processor



MARK VI BOARDS

I/O Terminal Board

I/O Board

Processor Card

Communication Card Protective Processor <X>, <Y>, <Z>

Rack Power Supply

Power Distribution Board



MARK VI I/O

General Purpose I/O

Contact Input

Relay Output

Analog I/O

Thermocouple Inputs

RTD inputs

Turbine specific I/O

Vibration Inputs

Speed Inputs

Servo channels for control valves (LVDT or LVDR )

Flame Inputs

Automatic Synchronizing



MARK VI COMMUNICATION

External Communication

HMI to Mark VI

HMI to DCS

Internal Communication

VCMI & Control processors DCMI to I/O boards

I/O signal flow

Unit data Highway (UDH)

Ethernet network between controllers and HMI Plant data Highway (PDH)

Connects HMI server with printers DCS etc



IONET

IONet is Ethernet network used to

communicate data between the VCMI

communication board in control module,

the I/O boards and three independentsections of protection module

IONet also communicate data between

controllers in TMR system



CONTROL SYSTEM TOOLBOX

Window based application used to configure & maintainMark VI control equipment

Primary function includes

Graphical based editor for configuring application code

Block macros and module library support

Live data block flow diagrams

On line code change

On line help files

I/O configuration & monitoring

Signal management and signal trending

Report Generation



PASSWORD ADMINISTRATION

0-Level: Read only like view, monitor live data

1-Level: All function allowed in 0-Level and Change

Controller Variables and signals and drive advanced

maintenance like change the value of variable, force

signals in a controller

2-Level: All function allowed in 0 & 1 Level and full

controller access and drive advanced maintenance like

make code change, download,put in database and get

from data base

3-Level: Drive Block Area and Menu maintenance like

alter block area and change application menu structure

4-Level: Fuull Drive access like change GE

parameter,edit hardware



CIMPLICITY

Cimplicity is a graphical interface made up ofone or more screens used to monitor and controlthe turbine operation

Cimplicity servers allows operator to directlyinterface to the mark VI controller (UDH) usinggraphical screen

The cimplicity server interface to the mark VI is

done by the cimplicity project. This project iscontrolled by a project file using cimplicity workbench program



TROUBLE SHOOTING TOOLS

Finder/Signal Browser

mark vi control

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