1. SPS Schemes for Grid Security (With Generation at Palatana) Case 1: When Palatana unit trips Case 2: 400 kV Palatana-Silcher (D/C) lines trip Case 3: 400 kV Silchar – Byrnihat line trips

2. Initial Conditions : Pre condition: Following lines should be kept in open condition  132 kV Khliehriat – Lumshnong S/C  132 kV Pailapool – Jiribam line at Jiribam end  132 kV Khleihriat (PG) – Khliehriat (Me) D/C (Based on Leshka Generation and System Conditions) Load (Drawal from Grid) in Southern Part of NER : Peak South Assam : 100 MW Manipur : 115 MW Mizoram : 75 MW Tripura : 145 MW Meghalaya : 15 MW (Lumshnong load) Total : 440 MW ISGS Generation in Southern Part of NER : Peak AGTPP : 75 MW Loktak : 105 MW Palatana : 350 MW Total : 530 MW

3. Badarpur (PG) Dullavchera Pailapool Lumsnong Khliehriat (Me) Panchgram Srikona Khliehriat (PG) Dharmanagar P K Bari Jiribam(PG) Udaipur S. Nagar Silchar Palatana Nehu NEIGRIHMS Line Flow in Initial Conditions System Requirement Shall be kept open Byrnihat Shall be kept open 20 MW 25 MW 35 MW 15 MW 90 MW 10 MW 6 MW 72 MW Khandong Kopili 34 MW Loktak(NH) 105 MW Imphal(PG) Dimapur(PG) Kumarghat(PG) AGTPP(NO) 75 MW 1 MW 19 MW 350 MW

4. Case 1: When Palatana unit trips (PEAK Case) Scheme: i.When generator at Palatana trips a signal will be generated from trip relay of the unit. ii.This signal should trip the CB of 132 kV Silchar – Srikona D/C & 132 kV Silchar – Panchgram lines at Silchar. iii.Subsequently, tripping of 132 kV Silchar – Panchgram line a signal will be generated from trip relay of 132 kV Silchar –Panchgram line. This signal should trip the CB of 132 kV Badarpur – Panchgram line at Badarpur. iv.After these trippings a instant load relief of 60 MW at off-peak & 105 MW in peak which will avert the system from cascade tripping v.Then manual demand disconnection should be imposed. Load Relief Off-Peak Peak Srikona : 15 MW 25 MW Pailapool : 10 MW 20 MW Panchgram: 20 MW 35 MW Lumsnong : 15 MW 25 MW Total 60 MW 105 MW

5. Badarpur (PG) Dullavchera Pailapool Lumsnong Khliehriat (Me) Panchgram Srikona Khliehriat (PG) Dharmanagar P K Bari Jiribam(PG) Udaipur S. Nagar Silchar Palatana Nehu NEIGRIHMS Line Flow After Tripping of Palatana Module-1 (350 MW) Shall be kept open Byrnihat Shall be kept open 20 MW 25 MW 35 MW 15 MW 82 MW 53MW 50 MW Khandong Kopili 59 MW Loktak(NH) 105 MW Imphal(PG) Dimapur(PG) Kumarghat(PG) AGTPP(NO) 75 MW 27 MW 143 MW System Requirement

6. Badarpur (PG) Dullavchera Pailapool Lumsnong Khliehriat (Me) Panchgram Srikona Khliehriat (PG) Dharmanagar P K Bari Jiribam(PG) Udaipur S. Nagar Silchar Palatana Nehu NEIGRIHMS Line Flow After SPS Operation Shall be kept open Byrnihat Shall be kept open 20 MW 25 MW 35 MW 15 MW 54 MW Khandong Kopili 28 MW Loktak(NH) 105 MW Imphal(PG) Dimapur(PG) Kumarghat(PG) AGTPP(NO) 75 MW 16 MW CB shall trip A signal will be generated from trip relay of 132 kV Silchar – Panchgram line When generator trips signal will be generated from trip relay of the unit 80 MW System Requirement

7. Case 2: When 400 kV Palatana-Silchar (D/C) lines trip (PEAK Case) Scheme: i.When both the ckts of 400 kV Palatana – Silchar lines trip, a signal will be generated from trip relays at Silchar ii.This signal should trip the CB of 132 kV Silchar – Srikona D/C & 132 kV Silchar – Panchgram lines at Silchar. iii.Subsequently, tripping of 132 kV Silchar – Panchgram line a signal will be generated from trip relay of 132 kV Silchar –Panchgram line. This signal should trip the CB of 132 kV Badarpur – Panchgram line at Badarpur. iv.After these trippings a instant load relief of 60 MW at off-peak & 105 MW in peak which will avert the system from cascade tripping v.Then manual demand disconnection should be imposed. Load Relief Off-Peak Peak Srikona : 15 MW 25 MW Pailapool : 10 MW 20 MW Panchgram: 20 MW 35 MW Lumsnong : 15 MW 25 MW Total 60 MW 105 MW

8. Badarpur (PG) Dullavchera Pailapool Lumsnong Khliehriat (Me) Panchgram Srikona Khliehriat (PG) Dharmanagar P K Bari Jiribam(PG) Udaipur S. Nagar Silchar Palatana Nehu NEIGRIHMS Line Flow After Tripping of 400kV Silchar-Palatana D/C Shall be kept open Byrnihat Shall be kept open 20 MW 25 MW 35 MW 15 MW 92 MW 38MW 54 MW Khandong Kopili 86 MW Loktak(NH) 105 MW Imphal(PG) Dimapur(PG) Kumarghat(PG) AGTPP(NO) 75 MW 43 MW 132 MW 350 MW System Requirement

9. Badarpur (PG) Dullavchera Pailapool Lumsnong Khliehriat (Me) Panchgram Srikona Khliehriat (PG) Dharmanagar P K Bari Jiribam(PG) Udaipur S. Nagar Silchar Palatana Nehu NEIGRIHMS Line Flow After SPS Operation Shall be kept open Byrnihat Shall be kept open 20 MW 25 MW 35 MW 15 MW 56 MW Khandong Kopili 35 MW Loktak(NH) 105 MW Imphal(PG) Dimapur(PG) Kumarghat(PG) AGTPP(NO) 75 MW 20 MW CB shall trip A signal will be generated from trip relay of 132 kV Silchar – Panchgram line When both the ckts of 400 kV Palatana – Silchar lines trip, signal will be generated from trip relays at Silchar 75 MW 350 MW System Requirement

10. Case 3: When 400 kV Silchar – Byrnihat S/C line trips (OFFPEAK Case) Load Relief Off-Peak Peak Srikona : 15 MW 25 MW Pailapool : 10 MW 20 MW Panchgram: 20 MW 35 MW Lumsnong : 15 MW 25 MW Total 60 MW 105 MW Scheme: i.When 400 kV Byrnihat – Silchar lines trip, signal will be generated from trip relays at Silchar ii.This signal should trip CB of GTG/STG of at Palatana. But unit will be running in FSNL iii.A instant relief in line loading of 230/130 MW which will avert the system from cascade tripping. v.Then manual demand disconnection should be imposed.

11. Badarpur (PG) Dullavchera Pailapool Lumsnong Khliehriat (Me) Panchgram Srikona Khliehriat (PG) Dharmanagar P K Bari Jiribam(PG) Udaipur S. Nagar Silchar Palatana Nehu NEIGRIHMS Line Flow After Tripping of Silchar - Brynihat Shall be kept open Byrnihat Shall be kept open 10 MW 15 MW 20 MW 15 MW 12 MW Khandong Kopili 59 MW Loktak(NH) 105 MW Imphal(PG) Dimapur(PG) Kumarghat(PG) AGTPP(NO) 75 MW 1 MW 34 MW 350 MW System Requirement 177 MW

12. Badarpur (PG) Dullavchera Pailapool Lumsnong Khliehriat (Me) Panchgram Srikona Khliehriat (PG) Dharmanagar P K Bari Jiribam(PG) Udaipur S. Nagar Silchar Palatana Nehu NEIGRIHMS Line Flow After Tripping of Silchar - Brynihat Shall be kept open Byrnihat Shall be kept open 10 MW 15 MW 20 MW 15 MW 101 MW Khandong Kopili 174 MW Loktak(NH) 105 MW Imphal(PG) Dimapur(PG) Kumarghat(PG) AGTPP(NO) 75 MW 32 MW 51 MW 350 MW System Requirement

13. Badarpur (PG) Dullavchera Pailapool Lumsnong Khliehriat (Me) Panchgram Srikona Khliehriat (PG) Dharmanagar P K Bari Jiribam(PG) Udaipur S. Nagar Silchar Palatana Nehu NEIGRIHMS Line Flow After SPS Operation Shall be kept open Byrnihat Shall be kept open 20 MW 25 MW 35 MW 15 MW 39 MW Khandong Kopili 94 MW Loktak(NH) 105 MW Imphal(PG) Dimapur(PG) Kumarghat(PG) AGTPP(NO) 75 MW 9 MW 43 MW 220 MW When 400 kV Byrnihat – Silchar lines trip, signal will be generated from trip relays at Silchar ST-1 shall trip System Requirement

14. Case 3B: When 400 kV Silchar – Byrnihat S/C line trips (PEAK Case) Load Relief Off-Peak Peak Srikona : 15 MW 25 MW Pailapool : 10 MW 20 MW Panchgram: 20 MW 35 MW Lumsnong : 15 MW 25 MW Total 60 MW 105 MW Scheme: i.When 400 kV Byrnihat – Silchar lines trip, signal will be generated from trip relays at Silchar ii.This signal should trip CB of GTG/STG of at Palatana. But unit will be running in FSNL iii.A instant relief in line loading of 230/130 MW which will avert the system from cascade tripping. v.Then manual demand disconnection should be imposed.

15. Badarpur (PG) Dullavchera Pailapool Lumsnong Khliehriat (Me) Panchgram Srikona Khliehriat (PG) Dharmanagar P K Bari Jiribam(PG) Udaipur S. Nagar Silchar Palatana Nehu NEIGRIHMS Line Flow After Tripping of Silchar - Brynihat Shall be kept open Byrnihat Shall be kept open 20 MW 25 MW 35 MW 25 MW 38 MW 20 MW 94 MW Khandong Kopili 96 MW Loktak(NH) 105 MW Imphal(PG) Dimapur(PG) Kumarghat(PG) AGTPP(NO) 75 MW 10 MW 40 MW 350 MW System Requirement

16. Badarpur (PG) Dullavchera Pailapool Lumsnong Khliehriat (Me) Panchgram Srikona Khliehriat (PG) Dharmanagar P K Bari Jiribam(PG) Udaipur S. Nagar Silchar Palatana Nehu NEIGRIHMS Line Flow After SPS Operation Shall be kept open Byrnihat Shall be kept open 20 MW 25 MW 35 MW 15 MW 33 MW Khandong Kopili 1 MW Loktak(NH) 105 MW Imphal(PG) Dimapur(PG) Kumarghat(PG) AGTPP(NO) 75 MW 9 MW 43 MW 220 MW When 400 kV Byrnihat – Silchar lines trip, signal will be generated from trip relays at Silchar ST-1 shall trip System Requirement