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11/21/11 J.H.Kim P.H.Kim

11/08/10 J.H.Kim P.H.Kim

DATE CHKD. CERT.

Project Title

Client

Consultant

in association with

Contractor

Document Title

REV.NO.

001

000

APPD.

D.J.Kim

D.J.Kim

DESCRIPTIONBY:

Issued for Approval (Revised as per discussion)J.H.Kim

J.H.Kim Issued for Approval

CONVERSION OF QURAYYAH OPEN CYCLE POWERPLANT TO COMBINED CYCLE POWER PLANT

PROJECT C

Functional Description and Logic Diagram for Block Load Control

DATE COMPLETED:

DOC. NO.

SAUDI ARABIA

DATE STARTED:

REV. NO.

THIS DOCUMENT IS NOT TO BE USED FORCONSTRUCTION OR FOR ORDERING

MATERIAL UNTIL CERTIFIED AND DATED

J.H.Kim

OPR'G. DEPT.:

CREATED BY: J.H.KimCHECKED BY:

ENG. DEPT.:

APPROVAL/CERTIFICATION INFORMATION

QURAYYAH

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Project : QURAYYAH CCPPSubject : Functional Description and Logic Diagram for Block Load ControlDoc. No. : 30621127-000-3BD-EE-01824

CONTENTS

1. General

2. Block Load Control (Station Load Control) Philosophy

3. Conceptual Operation Block Diagram

Appendix:

-. DCS Graphic for Block Load Control

-. Logic Diagrams for Block Load Control System

-. AGC Control Logic in Existing DCS

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1. General

The Block Load Control will be implemented in the Qurayyah Combined Cycle Power

Plant DCS control system. It will co-ordinate the electrical loading of the Gas Turbine

Generators (GTGs) and Steam Turbine Generators (STGs) and will provide setpoints toGTG control systems to achieve Block (Station) MW Control.

2. Block Load Control (Station Load Control ) Philosophy

The block (individual power block) total power demand (target) will be selected by anoperator selectable setpoint or load demand from LDC (Load Dispatch Center) and is

calculated by the DCS, which adjusts the individual load setpoints for each of the

operational GTGs.

Control of the power output from the individual GTGs will also be possible from their local

control panels using a local setpoint. Selection of the point of control will be from the

respective local control panel (remote for DCS control). All the setpoints for local and

remote operation are contained within the GTG respective local control panels. The

transfer from local to remote control and vice versa shall be bumpless.

STG MW OUTPUT

STGs MW output will be controlled separately. They will operate either on a speed/load

control or IPC (Inlet Pressure Control) the load will vary with the process conditions.

Th f h DCS i l d ll ill l id h MW d i f h

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Pre-select Load (Existing in Open Cycle) Station Load Control Base Load (Existing in Open Cycle)

When a GTG control panel is selected to remote operation, the DCS accepts the currentmode of operation which could be Pre-select load, Base load or Manual Raise/Lower.

Station Load Control mode is available only from the DCS. In this mode the DCS

determines the operational setpoint for each GTG based on an operator entered export

requirement. Whilst in any of the local panel modes of operation, the DCS Pre-select load

setpoint will track the GTG MW output.

The DCS receives status signals from the GTG for the current mode of operation and

whether the local control panel is in local or remote. The GTG local control panel is the

master for mode selection.

The DCS has the following analogue output to each GTG local control panel; Pre-select load

The Pre-select load signal to each GTG controller is used both for the Pre-select load and

the Station load control. For Pre-select load the operator selects the setpoint and for

Station load control the DCS determines the setpoint based on the station export

requirement. When neither of these modes are in use, the DCS tracks the GTG MW

output to ensure bumpless transfer on mode change.

Manual Speed/Load Control (Existing in Open Cycle)

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In Pre-select load mode the operator enters a setpoint for each GTG MW output. The

GTG local control panel must be set to remote before an operator can enter a setpoint.

Once the desired setpoint has been entered a confirmation will be required from the

operator before the setpoint is accepted. Only a valid setpoint will be accepted. If the

setpoint is not valid, or the conditions are not correct for the setpoint to be accepted then

the last value will be retained. The GTG local control panel uses the setpoint in a closedloop control system to maintain the desired output.

The limitation of maximum rate of GTG output increase or decrease is set within the GTG

local control panel. This prevents damage to the GTG due to the analogue either ramping

too fast or jumping.

Station load control

In Station load control mode, the operator sets a station Export MW output and the DCS

determines the Pre-select setpoint for each of the GTGs in this mode. The Export MW

value can also be set via grid control, but only if the operator has selected this mode of

operation. Station load control mode for a GTG can only be selected when the respective

local control panel is in remote and the circuit breaker is closed. A GTG has to be in

Station load control mode before an export setpoint can be entered. On selecting a GTG

to Station load control mode the current export MW will become the initial setpoint. If the

GTGs switched to this mode of operation are running at different MW outputs then the

setpoint to each will be adjusted by the DCS until the load is equally shared.

An operator will only be able to enter a valid export MW setpoint. This valid value could

be constantly changing depending on the number of GTGs in Station load control mode,

In house loading and the output of the units in other modes which are supplying load to

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GTG in Droop mode APS ON is Not Initiated

The GTG will exit from Station load control under the following conditions: GTG not remote mode

GTG circuit breaker not closed GTG Station load control Pushbutton OFF Initiated GTG not in Droop mode APS ON is Initiated GTG not pre-select mode GTG base load GTG Load Runback Initiated

Base load (Existing in Open Cycle)

In Base load mode, a GTG is run at its maximum output. The GTG can be set to Base

Load either locally at the control panel, or if the control panel has been set to remote from

the DCS. The GTG is ramped to its maximum output with various parameters (i.e.

temperature) constantly monitored. In the event of the temperature rising above a pre-set

value the output is ramped back to a pre-set point. This mode is configured in the GTG

local control panel. The DCS sends a signal to the GTG local control panel to switch to

Base load and monitors the operation. The GTGs will remain in this mode of operation

until a new mode is selected for each GTG.

3. Conceptual Operation Block Diagram

Refer to next page;

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Block Load Control is Highest Control Loop of APC

(Automatic Plant Control System) in Combined Cycle

Power Plant.

This Control Loop will decide Total Power Demand

and Station Export Power Demand as per Power

Plant Operation Condition or Power Demand fromLDC (Load Dispatch Center) and Control each

Turbine Generator Power.

What is Non STN (Station) Power ?

For GTG, Total MW in Operation Mode in PRESEL

(Fixed Load), not in Operation in Station Load Mode.For STG, Actual Power (MW) because this is always

Non STN Mode.

What is No of STN Mode ?

Number of GTG in Station Mode

What is In House Load ?

Power Consumption in the Qurayyah Power Plant

What is STG Load Control Concept?

STG Power Output will be Controlled under IPC (Inlet

Pressure Control) Mode (Like as Turbine Follow Mode

in Thermal Power Plant).

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Index for Block Diagram

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Appendix :

-. DCS Graphic for Block Load Control

-. Logic Diagrams for Block Load Control System

-. AGC Control Logic in Existing DCS

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Appendix-1- DCS Graphic for Block Load Control

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Appendix-2 - Logic Diagram for Block Control

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A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

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7/28/2009 11:40:51 AMLast Modified

V01.00.00AModule Revision Customer

AGC IN will be processed only when PER1& PER2 are satisfied.PER1 & PER2 will be specified at site by customer.Title

ELECTRICAL.AGC_1Software Path

5/26/2009 18:35:53Build Major Revision

ELEC1Device Name Site DM Number Requisition

V03.03.27CToolboxST Version DWG Engineer

000 00:00:00Build Minor Revision

8/21/2009 10:13:32 AMPrint Date Process Application Serial Number Shop Order Number Machine Size Cont. on Sh.

0001Sh. No.

SELECTOR_3 19

SELASELB

CASC

INA1

INB1

OUT1

GRP A

GRP B

O UT

C ONT R OL

SELECTOR

CASC

NOT_4 20

AND_5 21

MOVE_4 22

ENABLE

OR_4 23

NOT_5 24

LATCH_2 25

S

R

LATCH_4 32

S

R

LATCH_5 36

S

R

P_B_4 38

P_B_5 39

P_B_6 40

P_B_7 41

P_B_8 42

P_B_9 43

NOT_10 46

Same conditions as discussedabove for other GT's.

Latching of Auto and Manualsignals.

B3.P13MYB75GH001XT13

G3_MANUAL_LATCHLATCH_5.OUT 0001

EGD

B3.P13MYB75GH001XZ61

AGC_INLATCH_1.OUT 0000

EGD

G1_MANUALEGD

G1_AUTOEGD

G2_MANUALEGD

G2_AUTOEGD

G3_MANUALEGD

G3_AUTOEGD

SELECTOR_3.OUT1AGC_BLOCK1.PV3 0000

AGC_TRK3AGC_BLOCK1.TK3 0000

G1_MANUAL_LATCHELECTRICAL.AGC1_4.OR_1.IN2ELECTRICAL.AGC1_4.NOT_3.A

AND_3.IN2 0000OR_2.IN2 0000NOT_8.A 0000

EGD

G2_MANUAL_LATCHELECTRICAL.AGC1_2.OR_1.IN2ELECTRICAL.AGC1_2.NOT_3.A

AND_4.IN2 0000OR_3.IN2 0000NOT_9.A 0000

EGD

G3_MANUAL_LATCHELECTRICAL.AGC1_3.OR_1.IN2

EGD

NOT_4.NOT_AAND_5.OUT

0


MOVE_4.DEST

AGC_BLOCK1.PV3 0000


B3.P13MYB75GH001XT13G3_MANUAL_LATCH

B3.P13MYB75GH001XZ61NOT_10.NOT_A

GT3_STPTEGD ELECTRICAL.AGC1_3.SELECTOR_1.INB1

NOT_5.NOT_AG3_MANUAL_LATCH

NOT_4.NOT_AAGC_TRK3

AGC_BLOCK1.TK3 0000

AGC_IN

P_B_4.OUT

P_B_5.OUT

G1_MANUAL_LATCHEGD ELECTRICAL.AGC1_4.OR_1.IN2

P_B_6.OUT

P_B_7.OUT


P_B_8.OUT

P_B_9.OUT


G1_MANUAL

G1_AUTO

G2_MANUAL

G2_AUTO

G3_MANUAL

G3_AUTO

G3_MANUAL_LATCH

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AGC IN

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Logic for Unit wise operation.Title

ELECTRICAL.AGC1_2Software Path






0000Sh. No.

AND_1 3

SELECTOR_1 1

SELASELB

CASC

INA1

INB1

OUT1

GRP A

GRP B

O UT

C ONT R OL

SELECTOR

CASCOR_1 2

NOT_1 4

NOT_2 5

MOVE_1 6ENABLE

NOT_3 7

Logic for Unit wise operation.

Once unit wise control selected, AGC_Unit wisesetpoint will be processed for individual GT.If GTtaken into manual, operator can enter thesetpoint with bumpless transfer taken intoconsideration.If external load setpoint control DInot received from MarkVI, then MW feedbackfrom Mark VI will be processed.

Ref Screen : P12-MYA-01.cim

AGC_INELECTRICAL.AGC_1.LATCH_1.OUT

EGD

UNIT_SEL_1ELECTRICAL.AGC_1.NOT_7.NOT_A

EGD

G2_MANUAL_LATCHELECTRICAL.AGC_1.LATCH_4.OUT

EGD


AGC1.AGC_GT2


AGC_INUNIT_SEL_1

NOT_3.NOT_AB2.P12MYB75GH001XT13

AND_1.OUTOR_1.OUT

SELECTOR_1.OUT1

AGC1.AGC_GT2

GT2_STPT

P12MYB75GH001YQ66_F1EGD ELECTRICAL.AGC_1.SELECTOR_5.INB1


NOT_2.NOT_A

AGC_IN



GT2_STPTEGD ELECTRICAL.AGC_1.MOVE_3.DEST

G2_MANUAL_LATCH

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AGC IN

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0000Sh. No.

AND_1 3

SELECTOR_1 1

SELASELB

CASC

INA1

INB1

OUT1

GRP A

GRP B

O UT

C ONT R OL

SELECTOR

CASCOR_1 2

NOT_1 4

NOT_2 5

MOVE_1 6ENABLE

NOT_3 7




AGC_INELECTRICAL.AGC_1.LATCH_1.OUT

EGD


EGD


EGD


AGC1.AGC_GT3


AGC_INUNIT_SEL_1


AND_1.OUTOR_1.OUT

SELECTOR_1.OUT1

AGC1.AGC_GT3

GT3_STPT



NOT_2.NOT_A

AGC_IN




G3_MANUAL_LATCH

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00 00AGC_INEGD

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0000Sh. No.

AND_1 3

SELECTOR_1 1

SELASELB

CASC

INA1

INB1

OUT1

GRP A

GRP B

O UT

C ONT R OL

SELECTOR

CASCOR_1 2

NOT_1 4

NOT_2 5

MOVE_1 6ENABLE

NOT_3 7




ELECTRICAL.AGC_1.LATCH_1.OUTEGD


EGD


EGD


AGC1.AGC_GT1


AGC_INUNIT_SEL_1


AND_1.OUTOR_1.OUT

SELECTOR_1.OUT1

AGC1.AGC_GT1

GT1_STPT



NOT_2.NOT_A

AGC_IN




G1_MANUAL_LATCH

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