A PROJECT REPORT

ON

“DRIVE CONTROL PHILOSOPHY (STATION C&I)”

IN NTPC LTD., RAMAGUNDAM SUPER THERMAL POWER STATION.

SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENT OF THE AWARD OF DEGREE OF

BACHELOR OF TECHNOLOGY

IN

ELECTRONICS AND COMMUNICATION ENGINEERING

BY

GADDE SRIKIRAN (11103802)

UNDER THE ESTEEMED GUIDANCE OF

SRI. MANDADI PRASAD

Sr. Manager (O&M – C&I)

NTPC LTD., RAMAGUNDAM.

NATIONAL THERMAL POWER CORPORATION Limited

(A Government of India Enterprise)

RAMAGUNDAM SUPER THERMAL POWER STATION

CERTIFICATE

This is to certify that Mr. GADDE SRIKIRAN student of Lovely Professional University, Phagwara,

Dist. Jalandhar, Punjab, has done project entitled ” DRIVE CONTROL PHILOSOPHY (STATION C & I)”

in NTPC Ltd., RAMAGUNDAM SUPER THERMAL POWER STATION, Jyothinagar, Dist. Karimnagar,

Andhra Pradesh from 01-01-2014 to 15-01-2014.

The above project trainee has satisfactorily completed this project.

Sri. MANDADI PRASAD

Sr. Manager (O&M – C&I)

ACKNOWLEDGEMENT

The success and final outcome of this project required a lot of guidance and assistance from many people and I am extremely fortunate to have got this all along the completion of my project work. Whatever I have done is only due to such guidance and assistance and I would not forget to thank them. I would like to express profound gratitude to Sri DJ.SAHA, AGM in the C&I Department NTPS Ltd., Ramagundam, for allotting me this project in the Organisation and enabling me to complete the same successfully under his supervision. I am extremely grateful for his valuable guidance and support throughout the completion of project. I would like to extend sincere thanks to Sri E.NANDA KISHORE, AGM (HR-EDC), Sri P.M.G.V.SRINIVAS, DGM (HR-EDC) for giving this wonderful opportunity to do our project at NTPC Limited (RSTPS) also Sri KESHAVULU Sub-Officer (HR-EDC) and all the EDC staff members. I heartily thank our internal project guide Sri MANDADI PRASAD, Sr. Manager (O&M) C&I Department NTPC Ltd., Ramagundam for his guidance and suggestions during this project work. This acknowledgement will be incomplete if I fail to express my deep sense of obligation and reverence to my parents. They motivated me and provided me their moral support and encouragement throughout my career. Although I have tried to express my gratitude to every person who contributed to my project work,

there may still be someone hiding behind the veils of unknown, whom I may not have been able to

recognize. I would like to thank all of them who have worked for me without my knowledge

INDEX

1. Introduction of NTPC.

2. Control Philosophy.

3. Types of Drives.

4. Bi-Directional Drives.

5. Uni-Directional LT Drives.

6. Solenoid Operated Drives.

7. High Tension Drives.

8. Input /Output Redundancy.

9. Sequence Control Philosophy.

10. Sequence Mode Operation.

11. Unit Controller.

12. Functional Group Control.

13. Sub Group Control.

14. Sequential Start up Mode.

15. Analog Drives.

16. Conclusion.

17. Bibliography.

INTRODUCTION OF N.T.P.C

N.T.P.C Ltd. is a major corporation of power generation over one fourth of the total thermal

power in the country.

The corporation is maintaining its impeccable record by consistently generating reliable and

quality power establishment in 1975. N.T.P.C’s mission has been to construct commission and operate

power projects most economically and efficiently.

N.T.P.C Ramagundam is situated in the Godavari Valley coalfields and has one of India’s

largest thermal power stations. Ramagundam is considered as Manchester of India in light of the

companies around it. Some of them are Kesoram Cement, Basanth Nagar, N.T.P.C (RSTPS-

Ramagundam Super Thermal Power Station) Sourcing 2600 MW of power 24/7 and APSEB unit

Ramagundam. Around 24 unit’s coal mines belt Godavarikhani stretching 25 km are used in these

open coalmines.

There are many factories around this place that take the raw material from the coal mines

and prepare carbon derivatives and providing employment to more than 15000 people. The

temperature is hotter than most places in India a normal temperature is 40 degrees centigrade.

N.T.P.C has developed a technique to reduce the temperature by reducing the carbon dioxide

in its emissions and helped reduce the average temperature by 2 degrees centigrade from last one

decade.

N.T.P.C has a policy of hiring full time employer according to the production capacity. For the

records its present employers should not be more than 2600.

Total Land 10,000 Acres

Installed Capacity Stage I : 3X200 MW

Stage II : 3X500 MW

Stage III : 1X500 MW

Coal Source (i) South Godavari Coal Fields of Singareni

Collieries for stage 1 & 2.

(ii) Korba Coal feilds of SECL for Stage 3.

Water Source Sriram Sagar Dam on Godavari River, D-83 Canal from Pochampad.

Beneficiary States A.P, Pondicherry, Goa, Kerala, Karnataka,

Tamil Nadu.

Approved Investment Rs. 2059.22 Cr Stage 1 & 2

Rs. 1818.46 Cr Stage 3

Unit Commissioned Unit - 1 200MW Nov 1983

Unit - 2 200MW May 1984

Unit - 3 200MW Dec 1984

Unit - 4 500MW June 1988

Unit - 5 500 MW March 1989

Unit - 6 500MW October 1989

Unit - 7 500 MW August 2004

International Assistance IDA, IBRD Loan, OPEC, KFW, SFD, EXIM Bank , JAPAN.

Other Industries Kesoram Cement, Basanth Nagar

APSEB Unit Ramagundam

Heights of chimeney(s) 1. Stage I- 210M

2. Stage II-225 M

3. Stage III-275M

NTPS Ramagundam is considered to be one of the best in the nation. Less than 25% of the power

is provided to the state of Andhra Pradesh. NTPS owns 89.5% of shares and remaining shares are

owned by other public sectors. NTPC is classified as a “MAHARATNA”(a cash rich) company, meaning

it may run its operations independently and rise commercial financing without explicit government

nod.

NTPS Limited as 463 in the Forbes Global 2000, a listing of the world’s top public companies. It

has the stage of the art control room instrumentation facility. The Ramagundam Unit of the National

Thermal Power Corporation (NTPC) has bagged the Rajbhasa Award for 2002-03. The station has got

the unique distinction of recording 93 days of trip free operation and maximum continuous from run

for 355 days its 500MW unit VI during the year 1994-1995.

Dr. Arup Roy Choudhury, CMD, NTPC received the 'BT-Star Award 2013 given to NTPC for Excellence

in Human Resource Management from Shri Shekhar Dutt, Governor of Chhattisgarh, in the presence

of Bhupinder Singh Hooda, Chief Minister of Haryana.

NTPC Kawas received the first prize in the Thermal Power Stations Sector category in the

National Energy Conservation Award -2012 on 14th December, 2012. The Award was received by Shri

Shankar Das, General Manager, Kawas from President of India Shri Pranab Mukherjee at a function

held in Vigyan Bhawan.

NTPC has been awarded with the prestigious Energize Award 2012-13 as the "Energizer Company

of the Year" on July 27th, 2013. The award was been organized by Talwar Solutions Pvt. Ltd. (TSPL), in

association with CNBC TV18 with Smart Grid partner ABB and process Validation partner E & Y.

CONTROL PHILOSOPHY:

The control philosophy for different type of drives such as Bi-directional, unidirectional, Solenoid

operated ,H.T. drives under station C&I package are detailed below:

BI-DIRECTIONAL DRIVES (INCHING OR OTHERWISE)

1. All bi-directional drives shall be operable from Remote i.e., from Central Control Room

(CCR).Local operation of these drives is not envisaged.

2. Remote manual operation of all drives shall be done from LVS/CRT. Additionally back up

remote operation through PB station mounted on UCP for some of the essential drives is

provided.

3. Remote control commands i.e., open/close, generated from DDCMIS shall be issued to MCC

through interposing relays located in respective MCC.

4. Necessary electrical protections shall be realized at MCC, whereas process interlocks and

protections shall be realized in DDCMIS.

5. Following signal exchange shall take place between MCC & DDCMIS.

- Valve open & close command.

- MCC disturbance (when Overload relay operates or MCC Control power supply fails or

MCC power supply is isolated) for CRT alarm only.

6. Following signal exchange shall take place from valve actuator to DDCMIS.

- Valve status feedback by means of end position contact(open/close)

- Torque switch contacts (open/close).

- Valve position feedback (4-20mA) for inching duty drives.

- Actuators Thermostat contact is wired directly to the MCC control circuit.

UNIDIRECTIONAL LT DRIVES

1. Unidirectional LT drives shall be operable only from Remote i.e., from CCR. Local operation

of these drives is not envisaged except for LP dosing and Phosphate dosing system.

2. Remote manual operation of all drives shall be done under LVS/CRT. Backup remote operation

from PB station mounted on UCP is provided for some essential drives.

3. Remote control commands i.e., start/stop, shall be done from DDCMIS and shall be issued to

MCC through interposing relays located in respective MCC.

4. Emergency stop of the drive has been envisaged from the local push button provided near the

drive. The stop push button (stay put type) shall be provided with a press to lock and turn to

release type, keyless mechanism. Under locked position the drive operation is inhibited from

remote. The local emergency stop push button shall be wired directly to MCC.

5. Necessary electrical protections for the drive shall be realized at MCC, whereas process

interlocks and protections are realized in DDCMIS.

6. Following signal exchange shall take place between MCC & DDCMIS:

- Drive start & stop commands.

- Drive status feedbacks

- MCC disturbance (when thermal overload relay operates, control power supply fails,

Emergency local stop PB is pressed or MCC power supply is isolated) for CRT alarm only.

7. Suitable current transformer and transducer shall be provided in MCC wherever drive rating

is above 30kW and for a few essential drives below 30kW for remote monitoring in DDCMIS.

SOLENOID OPERATED DRIVES

1. Solenoid operated drives shall be operated from remote from CCR. Local operation of these

drives is not envisaged.

2. Remote manual operation of all drives shall be done from LVS/CRT. However, backup remote

operation from push button station mounted on UCP is provided for some essential drives.

3. Remote control commands i.e., open/close shall be generated from DDCMIS and shall be

issued to the solenoid through interposing relays located in the relay panel for the 240V AC

operated solenoid drives.

4. Remote control commands i.e., open/close shall be generated from DDCMIS and shall be

issued to the solenoid through interposing relays located in the MCC for the 220V DC operated

solenoid drives.

5. Necessary process interlocks shall be realized in DDCMIS.

6. The following signal exchange shall take place between solenoid operated drive and DDCMIS

for solenoids operating on 240V AC / 24V DC:

- Valve open/close command from DDCMIS through interposing relay mounted in relay

panel (for 240V AC solenoid only).

- Status feedback from the drive by means of limit switches.

7. Following signal exchange shall take place between MCC/Solenoid and DDCMIS for solenoids

operating on 220V DC:

- Valve open/close command from DDCMIS through interposing relay mounted in MCC.

- MCC disturbance (when Control Supply fails or MCC power supply is isolated) for CRT

alarm only.

- Status feedback from the drive by means of limit switches.

H.T.DRIVES

1. HT drives shell be operated only from remote i.e. from CCR. However , the Switchgear has

two modes of operation i.e. Service and Test. Service mode is normal modes of operation

when the drive is operable from remote i.e. from the LVS/CRT/UCP.

2. The Test position is envisaged to test the Switchgear, from swgr as well as remote, during

maintenance/ commission.

3. Remote manual operation of these drives shell be done from LVS/CRT. Back up remote stop

from UCP is provided for some essential drives.

4. Remote control commands i.e. start/stop, shall be generated from DDCMIS and shall be wired

to switchgear through interposing relays housed in respective switchgear.

5. Emergency stop of the drives has been envisaged from the local push button provided near

the drive. The stop button (stay put type) shall be provided with a press to lock and turn to

release type keyless mechanism. Under locked position the drive operation is inhibited from

remote. The local emergency stop pushbutton shall be wired directly to Switchgear.

6. Necessary electrical protection for the drive shall be realized at switchgear, whereas process

interlocks and protections are realized in DDCMIS.

7. Following signal exchange shall take place between Switchgear and DDCMIS:-

- Drive start & stop commands.

- Drive status feedbacks by means of ON & OFF contacts (in service/test position of

SWGR).

- Switchgear disturbance (control power supply failure, trip coil supervision failure).

- Switchgear available (Breaker spring charged, Breaker in service position and SWGR

selected in remote).

- Master trip relay operated (86 Relay).

- Trip on overload.

- Alarm on overload.

- Emergency stop PB operated.

8. Current transducer 4-20 mA type shall be mounted in the SWGR for monitoring the current in

DDCMIS. Auxiliary power supply to these transducers shall be from the control supply of the

respective switchgears.

I/O RDUNDANCY

Commands for all drives shell be through redundant outputs.

The drive status feedback for HT and some other important drives (total approximately 40 nos.per

unit) shell be through redundant inputs.

SEQUENCE CONTROL PHILOSOPHY

Sequence control is envisaged for start-up and shutdown of HT drives and LT drives for APH, LPH, HPH,

DMCWP, ACWP etc. and their associated drives for safe and efficient running of main drive. The drives

can be operated manually or automatically thorough group control and the process interlocks shell be

operative in both the modes.

SEQUENCE MODE OPERATION

Sequence controls are organised hierarchically in accordance with the operation concept of the plant

process. Accordingly following levels of sequence control exists.

Unit controller

Functional group control

Sub group control

UNIT CONTROLLER:

It is a level of control above functional group control, which coordinates between various functional

groups of whole plant taking care of the process requirement and the sequences

FUNCTIONAL GROUP CONTROL

The functional group control logic co-ordinates between functionally cascaded lower level sequence

control logics. It performs following functions:

1. Selection of drives as main, additional and standby.

2. Mode of operation.

3. Overall monitoring of sub group control (in case of failure of one sub group control it releases

automatic command to standby drives)

4. Sequential start/stop of sub group.

SUB GROUP CONTROL

Sub group control performs sequence control strategies on to main drive and related drives as

required by the process and taking care of the healthiness of each drive e.g. BFP along with its

recirculation valve, discharge valve and AOP in a sequence will form a sequence control logic for BFP.

SEQUENTIAL START UP MODE

1. Automated mode:

In this mode of operation, once the sequence memory is latched, the sequence shall progress

without involvement from the operator.

2. Semi-automatic mode:

In this mode of operation, once the sequence is initialized, the step progressing shell be

displayed on the CRT. But the step execution command shell be interlocked and shell be sent

by the operator via keyboard. It shell be possible to bypass and or simulate one or more

criteria to enable the program to proceed. This facility shell allow the program to executed

even if some criteria are not fulfilled. It shell be possible to put the system on the auto mode

after operating it on semi-auto mode steps or vice-versa, without disturbance to the sequence

operation.

3. Operator test mode:

It shell be possible to use the sequence control in operator guide mode/test mode i.e. the

complete system runs and receives input from the plant and the individual push button

station(wherever provided) / keyboards but its command output is blocked. The whole

program, in this case shell run in manual mode. This mode shall allow to practice manual

operation using step and criteria indications. The actual protection shall remain valid during

this mode of operation also.

ANALOG DRIVES

Analog drive interconnection to DDCMIS is established. Electric to Pneumatic converter shell be such

that on loss of control signal, the last set point pressure shell be maintained for stayput position.

A/M, Raise, Lower push buttons on UCP shall be provided for essential drives in line with analog drive

list.

CONCLUSSION

The Uni-Directional, Bi-Directional, Solenoid, High Tension, Low Tension drives are used in various

fields of the Power Plant. Each of the drive are having their own importance and respective uses.

A special type of switches are used for Emergency Stop/Start of the drives. The stop push button

(stay put type) shall be provided with a press to lock and turn to release type mechanism. Under

locked position the drive operation is inhibited from remote. The local emergency stop pushbutton

shall be wired directly to Switchyard.

The use of the spare system in case of emergency is being maintained in each and every type of

drive.

Different voltage level controlled solenoid drives are used in the Plant. E.g. 220V, 240V types of

solenoids drives are used.

BIBLIOGRAPHY

Wikipedia- control logics.

NTPC in plant website.

Modern Power Plant Practice Volume C, G, H.

Power Plant performance by AB GILL.

Power Plant Engineering by PK NAG.