1 th - Kar · U1 500 24-01-16 24-01-19 3rd PSS 4th PSS: TSGENCO vide letter dated 09.01.2017...

1 MOM of 6th PSS meeting - 27.09.2018

SOUTHERN REGIONAL POWER COMMITTEE BENGALURU

Record Notes of Deliberations of the 6th Meeting on PSS Tuning of Generators held

on 27th September 2018

The 6th Meeting on PSS related issues was held at SRPC, Bengaluru on 27th September

2018. The List of participants is furnished at Annexure-I. It was noted with concern that

there was no representation from KSEBL, NPCIL (KGS, MAPS & KKNPP), SEL, MEL,

JSWEL, IL&FS, SEIL (TPCIL & SGPL), HNPCL, UPCL, LKPPL & STCMS.

DGM, SRLDC welcomed the delegates to the meeting. He stated that low frequency

oscillations damping was required for such a large integrated grid and SR generators

were moving ahead with the PSS Tuning which was a welcome step.

SE(O), SRPC welcomed one and all to the meeting. He informed that MS, SRPC was

attending the PCSC meeting. He informed PSS tuning meeting was being held after one

year (5th meeting held on 26.07.2018) and non-participation by number of Generators on

the key issue was matter of concern. He informed that number of generators had

submitted the SRT reports which would be analyzed during the course of the meeting.

SRLDC has been contributing significantly in the analysis of the reports and their active

support was required to sustain the impetus. SRPC has also made a list of generators

whose SRT would be required to be redone as 3 years have been completed since last

test was taken up. Action plan in this regard would be discussed.

The following issues were deliberated during the meeting:

NTPC made a presentation on ‘AVR PSS Tuning in Excitation System of 490 MW

Unit-6 of NTPC through Modelling and software Simulation Studies’ (Annexure-II) of

brushless excitation system. The contract was awarded to M/s Emerson India (National

Institute of Poland would be taking up the project on behalf of M/s Emerson). The tests

had been carried out at one unit and the observations were under review and final

report was awaited. The action plan like adding one more lag-lead compensator, some

hardware/software modification may be considered and exercise may be repeated.


Subsequently the exercise would be taken up at few other units of NTPC. During the

process NTPC team would be trained to take up the tuning exercise at other units.

As noted in earlier PSS meeting, generators to furnish required information (Data

sheets for Generator, Excitation system, Governor (existing values) & Stabilizer Model)

from the field and the model details to SRLDC. SRLDC will use this information in

simulation and come out with the optimal Gain set points, which can be used as a

reference while carrying out the actual PSS Tuning.

Adani PL had earlier intimated that they are considering a centralized high frequency

sampling DR for their power plants. A Pilot project is envisaged at Mundra (as it has

HVDC, parallel AC line with FSC, generator at same location) and it will take another

six months’ time for the system to evolve. As there was no participation from

APL/UPCL, they are requested to furnish the update in the OCC meeting.

All the generators had been requested to get in touch with OEM for possibility of

permanent recording and logging of the PSS response which may be helpful in

assessing the PSS response in real time. KPCL informed that at Sharavathy GS, they

were trying to take data from existing temperature recorder. At Gerusoppa, Kadra and

Kodasalli new DAVR system was being procured in which time stamped recorder has

been specified. At Yeramarus recording facility was available. Krishnapatnam STPS

informed that the recording module was costing around 50-60 lakhs and procurement

was under consideration.

In the 5th Meeting of Grid Study Committee held on 18th June 2018, it was agreed that

NPC would constitute a Committee for PSS Tuning at national level.

The following needs to be ensure during the SRT and in the reports:

While furnishing the test results, MW Scale in graph needed to be taken

appropriately considering the operating range for better comparison and

conclusion.

Final adopted settings, damping factor, damping ratio and damping Torque

computation with and without PSS needed to be submitted.


Generators to inform SRLDC/SLDCS about SRT/PSS Tuning enabling SRLDC to

observe nearby PMUs.

Power System Stabilizer Models to be given along with the implemented settings

(Final).

SRT to be carried out at 50% and >80% loadings.

Both Step Up and Step Down tests needs to be carried out.

Real (Active) Power Scale to be within 10 % of operating point in the graphs.

Proper Graphs (soft copy) with visible scale to be provided. Make, Type & Model

of Excitation System to be provided.

Step up to be followed by Step down with a time gap of 20 sec, if taken up,

simultaneously.

Sample report of Raichur TPS is enclosed (Annexure-III). Generators were

requested to prepare the report on similar lines.


Highlight of the analysis, recommendation and schedule of next SRT is given in the

table below:

APGENCO

Station Name Status of PSS tuning

PSS to be tuned by

Analysed during

Comment

Rayalaseema TPS U1 to U5

U1 210 13-01-16 13-01-19 3rd PSS 6th PSS: APGENCO mentioned that next PSS Tuning is planned during Unit O/H from June 2019

U2 210 13-01-16 13-01-19 3rd PSS

U3 210 13-01-16 13-01-19 3rd PSS

U4 210 13-01-16 13-01-19 3rd PSS

U5 210 13-01-16 13-01-19 3rd PSS

Vijayawada TPS (NTTPS) U1 to U7

U1 210 01-04-16 01-04-19 3rd PSS 6th PSS: APGENCO mentioned that next PSS Tuning is planned during Unit O/H

U2 210 01-04-16 01-04-19 3rd PSS

U3 210 01-04-16 01-04-19 3rd PSS

U4 210 01-04-16 01-04-19 3rd PSS

U5 210 After AVR replaced with DAVR

N

6th PSS: APGENCO mentioned that next PSS Tuning is planned during Nov/Dec-2018

U6 210 After AVR replaced with DAVR

N 6th PSS: APGENCO mentioned that next PSS Tuning is planned during Nov/Dec-2018

U7 500 01-04-16 01-04-19 3rd PSS

6th PSS: APGENCO mentioned that next PSS Tuning is planned during Unit O/H

SDSPP (Krishnapatnam JV) U1 & U2

U1 800 12-04-18 12-04-21 6th PSS

6th PSS: Final adopted PSS parameters/settings need to be submitted. In future, the PSS tuning may also be carried out b/w 50% to 80 % loading of the m/c It is preferred that SRT is carried out in both the Channel 1 and Channel 2


U2 800 13-04-18 13-04-21 6th PSS

6th PSS: Final adopted PSS parameters/settings need to be submitted. In future, the PSS tuning may also be carried out b/w 50% to 80 % loading of the m/c It is preferred that SRT is carried out in both the Channel 1 and Channel 2

Lower Sileru HEP U1 to U4

U1 115 13-12-16 13-12-19 4th PSS

4th PSS:

SRT may be done with higher step change in the future

U2 115 N 4th PSS APGENCO vide letter dated 04-05-2017 replied that replacement would be carried out during R&M works

U3 115 N 4th PSS

U4 115 N 4th PSS

Srisailam RB HEP U1 to U7

U1 110 29-09-16 29-09-19 4th PSS SRT analysed

U2 110 29-09-16 29-09-19 4th PSS Final implemented settings furnished by APGENCO vide letter dated 06-09-2017

U3 110 28-09-16 28-09-19 4th PSS All the plots may be submitted for analysis

U4 110 29-09-16 29-09-19 4th PSS

APGENCO vide letter dated 06-09-2017 replied that PSS output is within the limits when tested at 2% and 3%

U5 110 30-09-16 30-09-19 4th PSS

APGENCO vide letter dated 06-09-2017 replied that electrical i.e., Uact follows Uref both in 5% and 10% SRT and found to be satisfactory



AP IPP's

Station Name Status of PSS tuning PSS to be

tuned by Analysed during

Comments/SRT report submitted or not


HNPCL, Vizag

U1 520 28-03-17 28-03-20 5th PSS

SRT at a different step response and 50 % loading may be carried out in the future. Model data and final PSS settings may be provided

U2 520 27-03-17 27-03-20 5th PSS

SRT carried out. Model data and final PSS settings may be provided

TSGENCO

Station Name Status of PSS tuning PSS to be tuned by

Analysed during Comments

Kakatiya TPS U1 & 2

U1 500 24-01-16 24-01-19 3rd PSS

4th PSS: TSGENCO vide letter dated 09.01.2017 informed that BHEL had intimated that there was a variation in field current during the test and was recorded in channel 3 which reflects the variation due to the step test. 6th PSS: TSGENCO to revert back with the schedule of next PSS tuning

U2 600 06-07-16 06-07-19 5th PSS

The step change for step-up and step-down is different. So comparison couldn’t be made. Same step change for up and down is to be taken for comparison

Kothagudem TPS U7 to U11

U7 120 01-03-18 01-03-21 6th PSS

6th PSS: Final adopted PSS parameters/settings along with Damping torque calculation need to be submitted In Channel-2, PSS ON plots at both the loadings may be furnished

U8 120 26-01-18 26-01-21 6th PSS

6th PSS: Final adopted PSS parameters/settings along with Damping torque calculation need to be submitted In future, the PSS tuning may also be carried out between 50% to 80 % loading of the m/c


U9 250 22-12-15 22-12-18 3rd PSS

4th PSS:

U10 250 22-12-15 22-12-18 3rd PSS

TSGENCO vide letter dated 09.01.2017 informed that BHEL had intimated that AVR output voltage is negative for converter operation positive for inverter operation, response recorded to be analyzed from this point of view 6thPSS: TSGENCO to revert back with the schedule of next PSS tuning

U11 500 22-12-15 22-12-18 3rd PSS

TSGENCO to revert back with the schedule of next PSS tuning

Nagarjunasagar HEP U1 to U8

U1 110 04-03-17 04-03-20

5th PSS

SRT analysed

U2 110 08-01-17 08-01-20 SRT analysed. The final implemented settings may be provided for U2 to U8 along with damping torque calculation. U3 110 08-01-17 08-01-20

U4 110 07-01-17 07-01-20

U5 110 07-01-17 07-01-20

U6 110 08-01-17 08-01-20

U7 110 08-01-17 08-01-20

U8 100.8 08-01-17 08-01-20

Srisailam LB HEP U1 to U6 U1 150 20-01-17 20-01-20

5th PSS

The PSS O/P is in phase with electrical power oscillation. Same may be discussed with OEM and revert to us. The final implemented settings may be provided along with damping torque calculation

U2 150 23-01-17 23-01-20

U3 150 21-01-17 21-01-20

U4 150 19-01-17 19-01-20

U5 150 22-01-17 22-01-20

U6 150 21-01-17 21-01-20

Other plots may be provided for comparison at k1=4. No significant damping is observed. Results may be discussed with OEM.


Singareni Collaries U1 & 2

U1 600 30-10-17 30-10-20 6th PSS

6th PSS: SRT with PSS ON/OFF is not done. PSS parameters need to be submitted along with damping torque calculation. PSS tuning may also be carried out between 50% to 80% loading of the m/c. SRT plots may be submitted for analysis. It is preferred that SRT is carried out in both the channel 1 and channel 2

U2 600 30-10-17 30-10-20 6th PSS

6th PSS: SRT with PSS ON/OFF is not done. PSS parameters need to be submitted along with damping torque calculation. PSS tuning may also be carried out between 50% to 80% loading of the m/c. SRT plots may be submitted for analysis. It is preferred that SRT is carried out in both the channel 1 and channel 2

KPCL


PSS to be tuned by

Analysed during

Comments

Raichur TPS U1 to U8




U4 210 06-09-17 06-09-20 6th PSS SRT analysed. It is preferred that SRT is carried out in both the Channel 1 and Channel 2

U5 210 24-11-15 24-11-18 4th PSS

With PSS off, there is continuous oscillation in the electrical power Output. Plots are not clear 6thPSS: KPCL to revert back with the schedule of next PSS tuning

U6 210 17-12-15 17-12-18 4th PSS SRT with a higher step change may be done in the future 6thPSS:


KPCL to revert back with the schedule of next PSS tuning

U7 210 17-12-15 17-12-18 4th PSS

Plots are not clear. To submit clear plots. SRT with a higher step change may be done in the future 6thPSS: KPCL to revert back with the schedule of next PSS tuning

U8 250 19-11-15 19-11-18 4th PSS

The scale of plots is not clear. To submit clear plots. SRT with a higher step change may be done in the future 6thPSS: KPCL to revert back with the schedule of next PSS tuning

BTPS U1 to U3

U1 500 15-10-15 15-10-18 4th PSS

Plots are not clear. To discuss results with OEM/Need to do again. SRT with a higher step change may be done in the future. 6thPSS: KPCL to revert back with the schedule of next PSS tuning

U2 500 31-12-15 31-12-18 4th PSS

Report submitted is for Voltage buildup test. PSS SRT reports to be submitted. 6thPSS: KPCL to revert back with the schedule of next PSS tuning


Yeramarus TPP

N 4th PSS Loaded the program. No operation of the unit above 50% load. SRT planned in January 2019

Varahi UGPH HEP U1 to U4

U1 115 23-10-16 23-10-19 4th PSS

Scale is not clear. It is suggested to take action as per the PSS study committee recommendations for the Units 1 & 2.

U2 115 23-10-16 23-10-19 4th PSS


U4 115 23-10-16 23-10-19 4th PSS SRT graphs to be resubmitted

Nagjheri HEP U1 to U6

U1 150 4/5-1-17 04-01-20 4th PSS SRT analysed

U2 150 4/5-1-17 04-01-20 4th PSS

U3 150 02-06-16 02-06-19 4th PSS SRT analysed and found satisfactory

U4 150 4/5-1-17 04-01-20 4th PSS SRT analysed


U5 150 4/5-1-17 04-01-20 4th PSS

SRT analysed. A higher step change may be considered in the future for the units 1, 2, 4 & 5.

U6 135 17-08-17 17-08-20 6th PSS

6th PSS: Final adopted PSS parameters/settings along with Damping torque calculation needs to be submitted. SRT may be carried out at a higher step in the future. It is preferred that SRT is carried out in both the Channel 1 and Channel 2.

Sharavathy HEP U1 to U10

U1 103.5 7/8-6-17 07-06-20 5th PSS

The final PSS settings along with datasheet may be provided. Higher step change may be considered in the future.

U2 103.5 7/8-6-17 07-06-20 5th PSS


U3 103.5 8-11-16, 12-11-16

08-11-19 4th PSS SRT analysed. SRT with higher step change may be done in future.

U4 103.5 7/8-6-17 07-06-20 5th PSS


U5 103.5 9-11-16, 11-11-16

09-11-19 4th PSS SRT analysed. SRT with higher step change may be done in future.

U6 103.5 7/8-6-17 07-06-20 5th PSS


U7 103.5 9-11-16, 10-11-16

09-11-19 4th PSS

SRT analysed The plots are not clear for Step-up at 80% loading of the machine.

SRT with a higher step change may be done in the future

U8 103.5 13-12-17 13-12-20 6th PSS

Damping torque calculation needs to be submitted. It is preferred that SRT is carried out in both the channel 1 and channel 2.

U9 103.5 10-11-16, 11-11-16

10-11-19 4th PSS

SRT analysed. SRT with higher step change may be done in future.


U10 103.5 11-11-16 11-11-19 4th PSS

KAR IPPs

Station Name Status of PSS tuning PSS to be tuned by

Analysed during

Comments

UPCL U1 & U2

U1 600 04-10-15 04-10-18

3rd PSS 4th PSS: The SRT may be carried out at 50% load in the future. 6thPSS: UPCL to revert back with the schedule of next PSS tuning

U2 600 23-10-15 23-10-18 3rd PSS

6thPSS: UPCL to revert back with the schedule of next PSS tuning

JSWEL U1 to U4

U1 300 15-02-17 15-02-20

5th PSS

5th PSS: SRT analyzed. PSS O/P plot is not plotted. Same

may be done in the future

U2 300 21-10-16 21-10-19

4th PSS Action to be taken as per PSS Study Committee recommendations

U3 300 21-10-16 21-10-19 4th PSS Action to be taken as per PSS

Study Committee recommendations

U4 300

DAVR of Unit 4 to

be changed

N

DAVR of Unit 4 to be changed

KSEBL


Analysed during

Comments

Idukki HEP U1 to U6 U1 130 Mar-18 N

KSEBL to revert back with the schedule of PSS tuning

U2 130 Dec-18 N KSEBL to revert back with the schedule of PSS tuning

U3 130 Jul-19 N


U4 130 Planned during 2022-23 N



TANGEDCO

Station Name

Status of PSS tuning PSS to be tuned by

Analysed during

Comments

NCTPS St-1 U1 to U3

U1 210 01-04-18 01-04-21 6th PSS

PSS tuning may be carried out at two steps in the future. Final adopted PSS parameter/settings need to be furnished along with damping torque calculation. It is preferred that SRT is carried out in both the Channel 1 and Channel 2.

U2 210 05-04-17 05-04-20 5th PSS

Oscillations in real power have damped down when PSS is ON but there is lot of noise. Revert to us after the results are discussed with OEM at 140 and 180 MW. Vide letter dated 20-09-2018, OEM replied that the observed noise in the field voltage and generator voltage after the activation of the PSS is due to the function and implementation of PSS2B and this is normal during step response


U3 210 06-04-17 06-04-20 5th PSS

Oscillations in real power have damped down when PSS is ON but there is lot of noise. Revert to us after the results are discussed with OEM at 140 and 180 MW . Vide letter dated 20-09-2018, OEM replied that the observed noise in the field voltage and generator voltage after the activation of the PSS is due to the function and implementation of PSS2B and this is normal during step response

NCTPS St-II U1 & U2

U1 600 22-02-17 22-02-20 5th PSS

No significant change in the Real power oscillations with PSS OFF and ON is observed. The results may be plotted on a narrow MW scale. Revert back after discussing results with OEM

U2 600 N

SRT is planned to be carried out after discussing the SRT observations of U1 with OEM

Tuticorin TPS U1 to U5

U1 210 03-02-18 03-02-21 6th PSS

PSS tuning may be carried out at two steps in the future. The damping torque calculation may be furnished. It is preferred that SRT is carried out in both the channel 1 and channel 2.



U4 210 28-12-16 28-12-19 4th PSS

SRT analysed. Final implemented PSS settings along with datasheet may be provided.

U5 210 29-12-16 29-12-19 4th PSS

PSS O/P may be plotted in the future. Final implemented PSS settings along with datasheet may be provided. Higher step change may be considered during the next SRT


Mettur St-I TPS U1 to U4

U1 210 09-10-17 09-10-20 6th PSS

6th PSS: Final adopted PSS parameters/settings need to be submitted along with damping torque calculation In future, the PSS tuning may also be carried out b/w 50% to 80 % loading of the m/c It is preferred that SRT is carried out in both the channel 1 and channel 2.

U2 210 22-07-17 22-07-20 5th PSS

5th PSS: Final adopted PSS parameters/settings need to be submitted along with damping torque calculation

U3 210 07-09-16 07-09-19 5th PSS


U4 210 09-10-15 09-10-18

PSS tuning of unit 4 will be again carried out on arrival of OEM. TANGEDCO to revert back with the next PSS schedule.

Mettur St-III TPS

U1 600 10-08-17 10-08-20 6th PSS

6th PSS: Damping torque calculation needs to be provided. It is preferred that SRT is carried out in both the channel 1 and channel 2.

Kadamparai HEP U1 to U4

U1 100 14-07-17 14-07-20 5th PSS

5th PSS: Final adopted PSS parameters/settings along with Damping torque calculation needs to be submitted. SRT may be carried out at a higher step in the future

U2 100 15-07-17 15-07-20 5th PSS

5th PSS: Final adopted PSS parameters/settings along with Damping torque calculation needs to be submitted. SRT may be carried out at a higher step in the future

U3 100 N

TANGEDCO to revert back with the PSS schedule.

U4 100 N

TANGEDCO to revert back with the PSS schedule.

TN IPPs


Station Name


Analysed during

Comments

STCMS

N

TNSLDC is suggested to follow up the PSS tuning and furnish SRT test reports before October 2018.

CGS/ISGS

Station Name


Analysed during

Comments

NTPC, Ramagundam STPS U1 to U7

U1 200 N

For Units 1,2; PSS to be carried out after replacement of DVR in 2019

U2 200 N

U3 200 01-05-17 01-05-20 5th PSS


U4 500 21-02-18 21-02-21 6th PSS

SRT may be also be carried out between 50% and 80% loading of the m/c. Damping torque calculation needs to be furnished. NTPC to discuss with OEM and revert back regarding oscillations. Clear SRT plots may be furnished

U5 500 N

NTPC would take up PSS tuning during Planned S/D next month.

U6 500 N

NTPC would take up during planned S/D next month

U7 500 19-10-16 19-10-19 4th PSS

NTPC, Ramagundam was suggested to take action to address the problem of hunting when PSS is ON by discussing the results with SRT agency


NTPC, Simhadri St-I & II U1 to U4 U1 500 14-03-16 14-03-19 3rd PSS

NTPC mentioned that next PSS tuning would be carried out during April/May 2019

U2 500 18-03-16 18-03-19 3rd PSS

U3 500 18-03-16 18-03-19 3rd PSS

U4 500 18-03-16 18-03-19 3rd PSS

NTPC, Talcher STPS St-II U3 to U6

U3 500 04-06-16 04-06-19 3rd PSS SRT report analyzed

U4 500 N NTPC mentioned that PSS tuning would be carried out in October 2018

U5 500 N NTPC mentioned that PSS tuning would be carried out in October 2018

U6 500 04-06-16 04-06-19 3rd PSS SRT report analyzed

NTPC, Kudgi

U1 800 10-09-16 10-09-19 5th PSS

SRT may be carried out at higher loading of the m/c (>80%) and at two steps in the future. Damping torque calculation may be furnished It is preferred that SRT is carried out in both the channel 1 and channel 2.

U2 800 02-11-17 02-11-20 6th PSS

SRT may be carried out between 50% and 80 % loading of the m/c and at two steps in the future. Damping torque calculation may be furnished. It is preferred that SRT is carried out in both the Channel 1 and Channel 2.

U3 800

NTPC to revert back with the status of PSS tuning

NTECL, Vallur TPS U1 to U3

U1 500 09-11-16 09-11-19 4th PSS SRT analyzed.

U2 500 08-11-16 08-11-19 4th PSS

SRT may be conducted at a higher step in the future. Test may be conducted at full load and reduced loading

U3 500 07-11-16 07-11-19 4th PSS SRT analyzed.

NLC, Neyveli TPS I Exp.

U1 210 12-10-15 12-10-18 3rd PSS Neyveli to revert back with the status of PSS tuning at the


U1 & U2 earliest

U2 210 05-11-15 05-11-18 3rd PSS Neyveli to revert back with the status of PSS tuning at the earliest

NLC, Neyveli TPS II U1 to U7

U1 210 18/19-4-

17 18-04-20 5th PSS

PSS O/P may be plotted in the future. Final adopted values may be provided.

U2 210 18/19-4-

17 18-04-20 5th PSS

On a query, it was mentioned that these 3 Stage I units were connected at 230 kV level. Also for +/-1% change in step, there was around 80 MVAr absorption. So, test couldn’t be carried out at a higher step.

U3 210 18/19-4-

17 18-04-20 5th PSS

It is suggested to follow PSS study committee recommendations

U4 210 23-12-16 23-12-19 4th PSS

U5 210 23-12-16 23-12-19 4th PSS

U6 210 23-12-16 23-12-19 4th PSS

U7 210 23-12-16 23-12-19 4th PSS

NLC, Neyveli TPS II Exp U1 & U2 U1 250 19-04-17 19-04-20 5th PSS

SRT analyzed. The PSS data sheet along with final implemented settings may be provided.

U2 250 19-04-17 19-04-20 5th PSS

SRT analyzed. The PSS data sheet along with final implemented settings may be provided.

(NLC & TN JV)NTPL U1 & U2

U1 500 24-05-17 24-05-20 5th PSS

From, the PSS OFF and ON graphs, it is not clear regarding the extent of damping in Electrical power oscillations. Clear plots may be resubmitted. The final PSS settings along with the datasheet may be provided


U2 500 02-08-17 02-08-20 6th PSS

All the graphs may be submitted for analysis with clear legend. SRT at higher loading of the m/c (>80%) may be done in future. The final adopted PSS parameters/settings and the damping torque calculation need to be furnished.

NPCIL, KGS U1 to U4

U1 220 PSS not in service N 4th PSS

Unit 1 - replacement of DAVR. KAIGA to revert back with the schedule of PSS tuning

U2 220 12-03-17 12-03-20 6th PSS

SRT may also be done at a higher step in the future. The final adopted PSS parameters/settings along with the damping torque calculation needs to be furnished. Loading of the m/c at which SRT was carried out is to be furnished.

U3 220 19-04-07 19-04-10 4th PSS PSS tuning for Unit 3 to be carried out in 2018.

U4 220 25-11-17 25-11-20 6th PSS

All the SRT plots need to be furnished for comparison. Step change in Vref needs to be mentioned. The final adopted PSS parameters/settings along with damping torque calculation needs to be furnished.

NPCIL, MAPS U1 & U2

U1 220 11-01-06 11-01-09 MAPS is suggested to carry out PSS tuning at the earliest.

U2 220 03-08-03 03-08-06

NPCIL, KKNPP

U1 1000 01-02-16 01-02-19 6th PSS

SRT may be carried out at two steps in future. The final adopted PSS settings along with damping torque calculation need to be furnished


U2 1000 21-02-17 21-02-20 6th PSS

SRT may be submitted with PSS O/P, Vref plots. SRT may be carried out at two steps in future. The final adopted PSS settings along with damping torque calculation need to be furnished

ISTS Connected IPPs

Station Name


Analyzed during

Comments

TPCIL (Thermo Power Tech) U1 & U2

U1 660 24-12-16 24-12-19 4th PSS SRT analyzed

U2 660 01-12-17 01-12-20 6th PSS The damping torque calculation needs to be furnished

Coastal Energen U1 600 17-07-17 17-07-20 6th PSS

The damping torque calculation needs to be furnished

U2 600 16-08-16 16-08-19 4th PSS

The PSS output signal was not plotted. Also a higher step change may

be considered in the future

IL & FS

U1 600 12-04-15 12-04-18 3rd PSS

IL & FS to revert back with the schedule of next PSS tuning at the earliest.

U2 600 14-04-16 14-04-19 4th PSS

The SRT with various step

changes in Vref and With &

Without PSS may be done in

future

Lanco Stage II & III

1*233+ 1*133+ 2*371

N

There was no representation from LKPPL. LKPPL was suggested to complete PSS tuning and furnish the SRT reports at the earliest

SGPL, Nellore 2*600 N

SGPL to ensure PSS tuning is done and report submitted at the earliest as per format


Vote of Thanks

SE(O), SRPC thanked the generators for submitting the reports in improved formats. SRT

was also being carried out by most of the generators in a time bound manner and the

effort needed to be sustained. He thanked the participants for their active deliberations.

He suggested that all generators complete the PSS tuning/Step Response Test for the

units as per schedule finalized.

*****************************


Annexure- IV

PSS STEP RESPONSE TEST ANALYSIS &

RECOMMENDATIONS

Brief Background

PSS is a device that enhances the damping of low frequency oscillations at the

synchronous machine by controlling excitation. As a benefit of the action of several PSSs

at several synchronous machines, the stability of the whole power system increases.

The low frequency oscillations that can be damped by the PSS are divided into following

modes

Local Mode – 1.0 to 2.0 Hz ( One generator swings against rest of the system)

Inter Area Mode – Around 0.3 Hz. ( Two Area’s swinging against each other)

Torsional Mode – 10 – 40 Hz. ( Generator Geometry )

Damping Torque


Settings of Recorder for BHEL excitation system:

• For the Graphs to be plotted of the Step Response Test (SRT) for BHEL AVR, the following

time scale settings maybe adopted in the graphs:

• Power: 0.5 V per div, full scale: 0 to 5 V DC, bandwidth/filter: 5 Hz

• PSS output: 50 mV per div, full scale: 0 to 5 V DC, bandwidth/filter: 5 Hz

• AVR Control Voltage: 2 V per div, full scale: -10 to +10 V DC, bandwidth/filter: 5 Hz

• Field Current: 0.5 V per div, full scale: 0 to 5 V DC, bandwidth/filter: 5 Hz

Analysis of SRT reports submitted:

APGENCO

SDSTPS

Unit - 1

Make & Model: Mitsubishi, model info Not Available.

The Test was done:

o With and without PSS for ± 3% at 660 MW (82.5 %)

o The oscillation have damped down significantly, the ∆D is 10 and 16 meets the

criteria ∆D > 10.

o Oscillation got reduced from 5 to 2 cycles

The Test is to be done in dual-channel, two different loadings of the machine and also the

channel changeover test.

The Excitation system along with PSS parameters is not submitted.

Unit - 2

Make & Model: Mitsubishi, model info not available.

The Test was done.

o With and without PSS for ± 3% at 660 MW (82.5 %)



criteria ∆D > 10.




The Excitation system along with PSS parameters is not submitted.

TSGENCO

KTPS

Unit - 7

Make: Not Available

The Test was done at 60 MW (50%)loading, both step up and down (± 2%) with PSS ON

and PSS OFF

o The Oscillations have better damping with PSS ON

o In Channel – 2, the PSS ON plot is missing

The Test was done at 80 MW (66%) loading, both step up and down (± 2%) with PSS ON

and PSS OFF


o In Channel – 2, the PSS ON plot is missing

The Excitation system along with PSS parameters and Damping Torque not given

Unit - 8

Make : Not Available

The Test was done at both step up and down (± 3%) with PSS ON and PSS OFF for 103

MW loading of the machine


o The Test was done in both the channel’s



Singareni TPP

Units - 1 & 2

Make & Model: Info. Not Available.

The SRT with and without PSS is not done. Only the Step test is done. (99% to 92% and

92% to 99%)



The Excitation system along with PSS parameters is not submitted

KPCL

Raichur Thermal Power Station

Unit - 4

Make: Not Available

The Test was done:

o With and without PSS for ± 2% at 203 MW


criteria ∆D > 10.



criteria ∆D > 10.

The Test is to be done in dual-channel

The Excitation system along with PSS parameters and Damping Torque has been

submitted by KPCL RTPS.

Nagjheri Hydro Power station

Unit - 6

Make: ANDRITZ HYDRO

The Test was done at 50% and Full loading with ± 4% step change


The Oscillation were well-damped with PSS In-service, the oscillation got reduced from 3

to 1 cycle.

The test is supposed to be done in two channels, the channel changeover and a higher step-

change in Vref


Sharavathy Hydro Power station

Unit - 8

Make & Model: Info. Not Available.

The Test was done:

o With and without PSS for ± 3% at 82 MW (80 %)


o With and without PSS for ± 3% at 55 MW (53 %)


The Test is to be done in dual-channel and also the channel changeover test.

TANGEDCO

MTPS

Stage - 1, Unit - 1

Make:- ABB, Model info not given

The Test was done at 180 MW loading, both step up and down (± 2%) with PSS ON and

PSS OFF


The Test was done at 180 MW loading, both step up and down (± 5%) with PSS ON and

PSS OFF

o The Oscillations have better damping with PSS ON , reduced from 5 to 1 cycle



Stage - 3

Make: ABB, UNITROL 5000

The Test was done at 450 MW (75%) loading, both step up and down (± 2%, ± 5%) with

PSS ON and PSS OFF

o The Damping of the machine is better with PSS ON

o However in PSS OFF, there is PSS Signal , it may be confirmed that the same is

not given to AVR Block.

The Test was done at 600 MW loading, both step up and down (± 2%, ± 5%) with PSS ON

and PSS OFF

o The Oscillations have better damping with PSS ON , reduced from 5 to 1 cycle


NCTPS

Stage - 1, Unit - 1

Make: ABB

The Test was done at 160 MW(76%) with ± 4% step change

o The Oscillation were well-damped with PSS In-service, the oscillation got reduced

from 4 to 1 cycle.

o The test is supposed to be done in two channels, the channel changeover and a

higher step-change in Vref


TTPS

Unit - 1

Make & Model: ABB.

The Test is done at 180 MW(85%) with ± 2%, and ± 4% step change

o The Oscillations were well-damped with PSS In-service.

The Damping Torque with and without PSS has not been calculated.


CGS/ISGS

NTPC Kudgi

Unit - 1

Make: Not Available

The Test was done at 500 MW(~62.5%) with ±3% step change

o The Oscillation were well-damped with PSS In-service, the oscillation got reduced

from 5 to 1 cycle.



The SRT at Full loading of the machine is not performed.

The Damping Torque calculation is not furnished

Unit - 2

Make: Not Available

The Test was done at 672 MW(~84%) with ±3% step change

o With and without is not mentioned.



The SRT at 50% loading of the machine is not performed

The Damping Torque calculation is not furnished

NTPC Ramagundam

Unit - 4

Make: SIEMENS PSS2B

The Test was done in channel – 1


o With PSS for ± 3% at 509 MW



o With and without PSS for ± 2% at 503 MW & 510 MW respectively

o With PSS for ± 3% at 506 MW

The SRT at 50% loading of the machine is not performed, in-addition the channel –

changeover test also may be performed

The Excitation system along with PSS parameters and Damping range has been

submitted by NTPC Ramagundam. The frequency range of damping oscillations is also

given.

NTPL

Unit - 2

Make: Not Available


o With and without PSS for ± 3% at 350 MW for K1 = 0.3 & K2 = 0.1

o With PSS for ± 3% at 350 MW for K1 = 2 & K2=0.1 & K1= 1& K2=0.1

The SRT at Full loading of the machine is not performed, in-addition the channel –

changeover test also may be performed

The Excitation system along with PSS parameters and Damping Torque is not given.

Kaiga APS

Unit - 2

Make: Not Available

The SRT was done with ± 2%

The test was conducted in Both Channel 1 & 2 , however the loading of the machine was

not given

The PSS Output is phase-opposition to the Electrical Power Oscillation

The Oscillation got reduced from 9 to 3 cycles in with and without PSS respectively.

The Excitation system along with PSS parameters and Damping Torque not given.



Unit - 4

Make: Not Available

The following details are missing

o Comparison of Electrical Power response for PSS ON vs OFF

o The Step Change in Vref is not mentioned.

o Channel 1 & Channel 2 the test is to be done.


KKNPP

Unit - 1

Make: JSC Power Machines



Unit - 2

Make: JSC Power Machines


The test was conducted in Both Channel 1 & 2 , at 1000 – 1020 MW loading

The PSS Output signal, Vref is not plotted

The Electrical Power Output has significantly damped with PSS ON in both the Channels.

However, the time Gap for Step Up and Step Down to be increased as the oscillations

have not yet damped for the step change in channel – 1

In additions the following Tests was also done

o Channel Changeover

o Automatic to manual Excitation regulation



ISTS connected IPPs

CEPL

Unit - 1

Make: ABB Unitrol 5000

Channel – 1

o The SRT was done with ± 2%, ± 4% & ± 5% @ 330 (55%) MW with and without

PSS

o The SRT was done with ± 2%, ± 4% & ± 5% @ 508 MW with and without PSS

Channel – 2

o The SRT was done with ± 5% @ 330 (55%) MW with and without PSS

o For The SRT was with ± 2% @ 330 (55%) MW without PSS is missing

o For The SRT was with ± 4% @ 330 (55%) MW With PSS is missing

The SRT was done with ± 2%, ± 4% & ± 5% @ 508 MW with and without PSS


TPCIL

Unit - 2

The Test was done in channel - 1 and channel - 2

o With and without PSS for 2%, 3% and 5% steps at 350 MW

o With and without PSS for 2%, 3% and 5% steps at 660 MW

o With PSS ON, the oscillations have damped down

Final adopted PSS settings have been furnished

The Damping Torque is not furnished.

1 th - Kar · U1 500 24-01-16 24-01-19 3rd PSS 4th PSS: TSGENCO vide letter dated 09.01.2017...

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Transcript of 1 th - Kar · U1 500 24-01-16 24-01-19 3rd PSS 4th PSS: TSGENCO vide letter dated 09.01.2017...