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BLACK START AND
RESTORATION PROCEDURES OF
NER GRID
7th REVISION
Month : 03rd Jan 2012
POWER SYSTEM OPERATION CORPORATION LTD (A wholly owned subsidiary of POWERGRID)
NORTH EASTERN REGIONAL LOAD DESPATCH CENTRE SHILLONG
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CLASSIFICATION : OPEN
BLACK START AND RESTORATION PROCEDURES OF NER GRID
Doc. Code: NERLDC/SO/ MANUAL
Checked by:
Verifed by Reviewed by Approved by: Prepared and Issued by:
Sh. Anupam Kumar,
Engineer, NERLDC
Sh.B.Medhi, Sr.Engineer,
NERLDC
Sh.N.R.Paul, DGM(SO), NERLDC
Sh.T.S.Singh, AGM,
NERLDC
Sh. B.Medhi Sr.Engineer,
NERLDC
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CONTENTS
Sl No
Chapter : Page No
1 Black Start Facility
4
2 System Restoration Approach
6
3 Power Map of NER
11
4 Network Diagram of NER
12
5 Broad classification of NER Grid
13
6 Black Start & Restoration Procedures :
25
Restoration of NER Grid after total collapse, when power from ER is available
26
Restoration of NER Grid after total collapse, when power from ER is not available
50
Restoration of 132 kV Network, comprising of Nagaland, Manipur, South Assam, Mizoram, Tripura and Meghalaya, after partial collapse
60
Restoration of 132 kV Network, comprising of Nagaland, Manipur (except Jiribam) and Loktak, after partial collapse
62
7 Reporting Procedure
64
Annexures :
I List of Power Stations, whether Black Start facility is available
68
II List of Sub-Stations, whether synchronizing facilities is available
72
III List of Shunt Reactors in NER
74
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CHAPTER 1
BLACK START FACILITY
1.1 Existing Black Start Facilities :
A list of Generating Stations of NER (North Eastern Region) having black start facilities is
elaborated in Annexure-I
1.2 Survival/ Auxiliary Power requirement:
Survival/Auxiliary power is required to avoid damages of some equipments as well as
functioning of some essential facilities, in case of supply failure. Immediate arrangement of
power is very essential for the following:-
1. Battery Charging
2. Emergency Lighting
3. Compressors for breaker operation
4. Lubricating Oil Pumps
5. Communication & Telemetry System
6. Turbine Emergency Oil Pump
In power stations of NER, auxiliary power requirement is very nominal i.e. around 100-150
kW as unit sizes are small except Ranganadi units.
1.3 Start up power requirement:
For restoration of Generating Unit, start up power is required for its auxiliaries. The
requirement of Start up power of various units is as follow:-
Gas - 2 % of Unit Capacity
Hydro - 1 % of Unit Capacity
Start up power requirement for Gas Generating Unit is high as the major auxiliaries like Gas
Compressor, BFP, ID Fan, FD Fan, CW Pump etc. are of bigger size and the starting torque is
large. However, start up power requirement for Hydro Generating Unit is less because of few
auxiliaries.
List of DG Set installed in the Generating Stations is at Annexure-I
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1.4 Synchronizing facilities at Power Stations / major Sub-Stations :
Synchronizing facilities play a vital role in building up of systems and also for inter-
connection of different sub-systems/islands. List of major Sub-Stations which have
synchronization facilities is indicated at Annexure-II.
1.5 Shunt Reactors at major Power Station and Sub-Stations:
It is very essential to contain voltage during the restoration process of a collapsed system.
During the early restoration process, lines are generally lightly loaded due to the restricted drawl
by the drawing utilities and voltage starts rising up in different buses as system size grows. Shunt
Reactors play a vital role to contain voltage. List of Shunt Reactors available in NER is indicated
in Annexure - III.
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CHAPTER 2
SYSTEM RESTORATION APPROACH
The following specific points must be adopted considering the importance of system
restoration:-
2.1 General Guidelines:
i) This document should be available in the Control Room of each Load Despatch
Centre & readily accessible to all system operators.
ii) Black Start and Restoration Procedure of Regional Grid under various conditions
(Partial / Total Blackout) shall be reviewed/updated by NERLDC annually in
consultation with NLDC, all Users, STU, SLDC, CTU and NERPC Secretariat. (As
per Clause No 5.8.a of IEGC)
iii) Black Start and Restoration Procedure of each system of User’s/STU/CTU within a
Region under various conditions (Partial / Total Blackout) will be finalized by the
concerned User’s/STU/CTU in co-ordination with NERLDC. The procedure will be
reviewed, confirmed and/or revised once every year. Mock trial run of this procedure
for different sub-system shall be carried out by User’s/STU/CTU at least once in
every six months under intimation of NERLDC. Diesel Generators set for black start
would be tested on weekly basis and test report shall be sent to NERLDC on quarterly
basis. (As per Clause No 5.8.b of IEGC)
iv) List of essential loads with categories to be prepared by User/SLDC and sent to
NERLDC. Inter State/Inter Regional links, synchronizing points and essential loads to
be restored on priority shall be available with NLDC, RLDC & SLDC. (As per
Clause No 5.8.c of IEGC)
v) NERLDC will co-ordinate entire restoration process through SLDC /ISGS
/POWERGRID etc.
vi) During restoration process, NERLDC is to be allowed to operate the Grid with
reduced security standard for voltage and frequency in order to achieve fastest
possible recovery. (As per Clause No 5.8.d of IEGC)
vii) All communication channels required for voice communication during the restoration
process must be operational. At least one channel of voice communication is to be
kept free for NERLDC communication. (As per Clause No 5.8.e of IEGC & As per
Clause No 17 of CEA (Grid Standards) Regulation)
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viii) Healthiness of communication system and ancillaries at all Load Despatch Centres,
Power Stations and Sub-Stations should be checked at least once in every week to
ensure availability of communication system during the periods of crisis.
ix) List of PSTN, Mobile & ULDC phone numbers of Control Rooms of all Load
Despatch Centres, Power Stations and important Grid Sub-Stations should be
available at all Control Rooms and to be distributed to all concerned. Any change or
addition of above phone numbers should be incorporated time to time and to be
communicated to all concerned.
x) Constituents should organize one day appreciation course on power system
restoration at regional level, at least once in a year for
a. Top Management Group/Chief of Load Despatch Centres
b. Load Despatch Personnel/Power System Operators/Sub-Station Operators
xi) System Operators are expected to be thoroughly conversant with
a. Reactive Capability of Generators
b. Voltage Control through the following means :-
• Charging the shorter line first • Switching off Capacitor Bank • Taking Bus Reactors into service • Charging Transformers and taking Bus Reactors into service • Converting Line Reactors into Bus Reactors wherever feasible. • Operating Generators at minimum Voltage levels • Changing Transformer Taps • Energisation of fewer High Voltage Lines.
c. Network connectivity by heart and
d. They should be able to converse fluently in Hindi/English
xii) Power Station which has Black Start capability should be tested at least once in a
month. Power Station which has DG Set should be explored for Black Start
Capability.
xiii) Synchronization facility wherever available should be checked periodically and
should be kept in working condition. Periodic report of non-functioning of
Synchronoscope is to be sent to NERLDC.
xiv) All equipments such as Disturbance Recorders and Event Loggers shall be kept in
healthy condition, so that under no condition such important data is lost. Periodic
report of non-functioning of Disturbance Recorder/Sequential Event Recorder to be
sent to NERLDC. (As per 15.4 of CEA (Grid Standards)Regulation)
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xv) Priority wise loads are to be secured in steps during restoration process. This is to be
documented by each User/SLDC and informed to NERLDC.
xvi) OLTC of Transformers shall be tested at least once in a week. Periodic report of non-
functioning of OLTC of Transformer to be sent to NERLDC.
2.2 Initial Course of Action:
i) Assess (a) extent of black out, (b) whether any sub-system/island is alive or not, (c)
whether interconnection with ER is still there or not. If interconnection with ER is
there, then how much load can be connected
ii) Appraise the severity of disturbance to all concerned.
iii) Open all circuit breakers at Power Station / Sub-Stations that have blacked out, to
establish well defined starting point of restoration.
iv) Note the relay indications and reset them, if operated.
v) Check whether any equipment or any element has suffered damage or developed a
technical snag.
vi) Chalk out the optimum path for restoration after checking the grid elements that were
under outage before disturbance.
vii) Defer all planned outage as per IEGC 5.7.4 (g)
2.3 Important Considerations during Restoration :
i) Generating Stations which have black start facilities have to start up immediately.
ii) Availability of Generation Capacity in each island / sub system to be ensured.
iii) Availability of transmission lines in the interconnection between islands / sub systems
to be ensured.
iv) Load to be added in small steps with smaller and radial loads. Larger load may be
connected after consultation with NERLDC.
v) For developing island / sub system, special care should be taken to closely co-
ordinate the load pick-ups with the ramp rate of generation and to be ensured that the
frequency of the island is maintained within sustainable limit (around 50 Hz).
vi) If required, Governor and AVR of the units of the island are to be kept in manual
mode.
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vii) UFRs are to be kept deactivated as frequency excursions at this stage may be wider
than normal condition. SPS are also to be kept deactivated.
viii) A reasonable active to reactive power ratio is to be maintained so that the machine
can be operated normally.
ix) Auxiliary power to be readily available so that machine can be operated normally.
x) Total auxiliary power drawn by the sub-system to be kept within 3% of the capacity
of the source.
xi) Before synchronization between two islands there should be proper co-ordination for
frequency adjustment.
xii) Risky synchronization shall be avoided as small island may not be able to survive the
jerk
xiii) While releasing loads, it is to be ascertained whether machines can supply the power.
xiv) Tap Position of Transformer, Bus Voltage and Frequency at Power Stations and Sub-
Stations should be closely monitored to ensure that over fluxing does not occur.
xv) Shift personnel should promptly formulate the strategy to be adopted in co-ordination
with NERLDC for quick restoration of the Grid.
xvi) The work of restoration in the Control Room should be shared & co-ordinated among
the shift personnel for smooth & quick restoration. Crisis Management Group to be
formed, consisting of expert personnel & called for early restoration of the system.
xvii) Shift personnel should preferably be retained till restoration is over, before handing
over the charge to the next shift.
2.4 Special Consideration in extending/availing start up power:
I. Power Plant Operators should be able to differentiate between the followings :
a. Full auxiliary power needed to start all machines
b. Minimum auxiliary power needed to start a minimum number of machines.
II. For availing start up power, the following considerations should be kept in mind :
a. Nearness to the source
b. 132 kV lines vis-à-vis 220 kV/ 400 kV lines
c. Shorter route having a number of intermediate sub-stations vis-a-vis longer route
having very few/ no intermediate sub-stations
III. For extending start up power from one sub-system to another sub-system or from one
utility to another utility, the following clear-cut authority should be given to SLDC :-
a. Line through which start up power is to be extended
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b. Quantum of such start up power
c. Normal time period admissible
IV. Concerned SLDC should also be empowered to resort to load shedding or bring up
additional generation wherever possible, to extend start up power to neighboring sub-
systems/utilities during the period of crisis.
2.5 DON’TS:
i) Do not panic
ii) Do not load any Generator beyond 80% of its capacity
iii) Do not load any Line/ICT beyond 80% of its capacity
iv) Do not hastily connect loads and ensure that the island / sub-system frequency be
within sustainable range
v) Once power extended to a Power Station/Utility, it should not be withdrawn except
in case of extreme emergency and without intimation to NERLDC, as actions taken
up at Power Stations would have to be redone.
vi) No communication disputes should be raised during the restoration period.
vii) Till the restoration procedure is over, load despatch centers should not be disturbed
in undesirable manner while discharging their duties and they should not be
expected to function as Management Information System.
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Power Map of North Eastern Region CHAPTER 3
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CHAPTER 4
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CHAPTER 5
BROAD CLASSIFICATION OF NER GRID:
5.1 North Eastern Region (NER) comprises of seven states viz Arunachal Pradesh,
Assam, Manipur, Meghalaya, Mizoram, Nagaland & Tripura. NHPC & NEEPCO are
the Central Generating Companies presently operating in the region with installed
capacity of 105 MW & 1130 MW respectively. Total installed capacity of the region
connected to the NER Grid is 2091 MW.
Depending on the network connectivity, NER Grid is broadly classified as follows.
1. 400 / 220 kV Network of POWERGRID as backbone of NER
Grid
2. 220 / 132 kV Network of Assam System
3. 220 / 132 kV Network of Arunachal Pradesh System
4. 132 kV Network comprising of Nagaland, Manipur, South
Assam, Mizoram, Tripura and Meghalaya
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5.1.1 400 / 220 kV Network of POWERGRID as backbone of NER Grid:
This is the main back-bone network of NER Grid comprising of 400 kV and 220
kV transmission lines of POWERGRID(PG). NER Grid is connected to ER Grid
through this network. The network configuration is described as below:
a. 400 kV Bongaigaon (PG) Sub-Station of NER is connected with 400 kV New
Siliguri (PG) Sub-Station of ER through 400 kV D/C New Siliguri –
Bongaigaon lines.
b. 220 kV Salakati (PG) Sub-Station of NER is connected to 220 kV Birpara
(PG) Sub-Station of ER through 220 kV D/C Birpara – Salakati lines. 220 kV
Salakati Sub-Station and 400 kV Bongaigaon Sub-Station are connected
through 315 MVA ICT.
c. Bongaigaon (PG) Sub-Station is connected to Balipara (PG) Sub-Station
through 400 kV D/C Bongaigaon – Balipara lines.
d. 400 kV D/C Balipara – Misa lines and 400 kV D/C Balipara – Ranganadi
lines connect Balipara (PG) Sub-Station with Misa (PG) Sub-Station and
Ranganadi (NEEPCO) Power Station respectively. 400 kV Bus of Misa is
connected to 220 kV Bus through 315 MVA ICT.
e. Misa (PG) Sub-Station is connected with Kopili (NEEPCO) Power Station,
Dimapur (PG) Sub-Station and AGBPP (NEEPCO) through 220 kV T/C Misa
– Kopili lines, 220 kV D/C Misa – Dimapur lines and 400 kV S/C Misa –
Kathalguri line (charged at 220 kV) respectively.
f. Misa (PG) Sub-Station is also connected to Mariani (Assam) Sub-Station and
Samaguri (Assam) Sub-Station through 220 kV S/C Misa – Mariani line and
220 kV D/C Misa – Samaguri line.
g. Misa (PG) Sub-Station is connected with Killing (Byrnihat) Sub-Station of
Meghalaya through 220 kV D/C Misa – Killing lines.
h. Mariani Sub-Station is connected to AGBPP (NEEPCO) through 400 kV S/C
Mariani – Kathalguri line (charged at 220 kV)
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5.1.2 220 / 132 kV Network of Assam System:
Assam has its own 220 kV & 132 kV Network through which it is connected to the
Main Grid. Except South Assam, connectivity of Assam system with the Main Grid is
better than other states’ connectivity to the Main Grid. Connectivity of Assam system
with the Grid is as follows:-
a. BTPS (Assam) Sub-Station is connected with Salakati (PG) Sub-Station
through 220 kV D/C BTPS – Salakati lines. Again, 220 kV Bus of BTPS is
connected to 132 Bus through 2 X 80MVA + 1 X 160 MVA.
b. Dhaligaon, Barnagar, Nalbari, Rangia, Rowta, Sipajhar , Sisugram and Depota
Sub-Stations are connected with BTPS, Kahilipara, Pavoi, Samaguri and
Balipara (PG) Sub-Stations through 132 kV lines. 220 kV Bus of Samaguri
Sub-Station is connected to 132 kV Bus through 3 X 50 MVA ICT. Again,
Samaguri Sub-station is connected with Balipara (PG) Sub-station through 220
kV Samaguri – Balipara S/C line.
c. Agia Sub-Station is connected with BTPS Sub-Station through 220 kV D/C
BTPS – Agia . Presently, one circuit of 220 kV BTPS – Agia is under outage.
d. Sarusajai Sub-Station is connected with Agia Sub-Station through Agia –Boko-
Sarusajai line and Agia – Sarusajai respectively.
e. Sarusajai Sub-Station is connected with Samaguri Sub-Station and Langpi
Power Station through 220 kV D/C Sarusajai – Samaguri lines and 220 kV D/C
Sarusajai – Langpi lines respectively.
f. Kahilipara Sub-Station is connected with Sarusajai Sub-Station through four
numbers of 132 kV Sarusajai – Kahilipara lines & with Rangia Sub-Station
through 132 kV Kahilipara –Sishugram - Rangia & 132 kV S/C Kahilipara –
Rangia lines.
g. LTPS, NTPS, Tinsukia and Dibrugarh Sub-System is connected with Mariani
Sub-Station and AGBPP through 132 kV S/C LTPS - Mariani and 220 kV D/C
Tinsukia – AGBPP lines respectively.
h. Mariani, Golaghat and Bokajan Sub-Stations are connected with Dimapur (PG)
Sub-Station through 132 kV S/C Mariani – Golaghat - Bokajan - Dimapur line.
i. Gohpur, Pavoi (Bishwanath Chariali), North Lakhimpur, Dhemaji and Majuli
Sub-Stations are connected with Nirjuli (PG) Sub-Station through 132 kV S/C
Nirjuli – Gohpur line. Gohpur, Pavoi (Bishwanath Chariali), North Lakhimpur,
Dhemaji and Majuli Sub-Stations are also connected with Balipara (PG) Sub-
Station through 132 kV Balipara – Gohpur line and with Samaguri and Depota
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Sub-Stations through 132 kV Samaguri – Depota – Pavoi line (T-connection
near Depota in between Depota & Pavoi).
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5.1.3 220 / 132 kV Network of Arunachal Pradesh System :
The connectivity of 220 kV & 132 kV Network of Arunachal Pradesh is as follow :-
a) Ziro(PG), Daporizo and Along Sub-Stations are connected with Ranganadi
(NEEPCO) Power Station through 132 kV S/C Ranganadi – Ziro line.
b) Nirjuli (PG) Sub-Station is connected with Ranganadi (NEEPCO) Power Station &
SMS Sub-Station of Arunachal through 132 kV S/C Ranganadi – SMS - Nirjuli line
(T Connection at SMS) and also with Gohpur Sub-Station of Assam through 132
kV S/C Nirjuli – Gohpur line.
c) Itanagar Sub-Station is connected with 132 kV Nirjuli (PG) Sub-Station through
four nos. 33 kV feeders. Again, Itanagar can draw power from SMS Sub-station via
Naharlagun Sub-station through 132 kV SMS – Naharlagun-Itanagar line (Presently
charged at 33 kV).
d) Khupi, Kimi Sub-Stations are connected with Balipara (PG) Sub-Station through
132 kV S/C Balipara – Khupi - Kimi line and Deomali is connected with AGBPP
(NEEPCO) through 220 kV S/C AGBPP – Deomali line respectively.
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5.1.4 132 kV Network comprising of Nagaland, Manipur, South Assam,
Mizoram, Tripura and Meghalaya :
The connectivity of 132 kV Network comprising of Nagaland, Manipur, South
Assam, Mizoram, Tripura and Meghalaya is as follow :-
1. Nagaland System is connected with the Main Grid through :-
a. 132 kV D/C Dimapur (PG) – Dimapur line.
b. 132 kV S/C Dimapur (PG) – Kohima line.
c. 132 kV S/C Karong (Manipur) – Kohima line.
d. 132 kV S/C Doyang (NEEPCO) - Mokokchung line.
e. 132 kV S/C Mariani (Assam) – Mokokchung line.
f. 66 kV S/C Dimapur – Bokajan (Assam) line
** Nagaland is also connected with Assam system through the following 33 kV and
11 kV feeders :
i) Gargaon – Naginimara
ii) Sonari – Tigit
iii) Chanki - Moriani
2. Manipur System is connected with the Main Grid through :-
a) 132 kV S/C Imphal (PG) – Imphal line.
b) 132 kV S/C Kohima (Nagaland) – Karong line.
c) 132 kV S/C Loktak (NHPC) – Ningthoukhong line.
d) 132 kV S/C Loktak (NHPC) – Rengpang line.
e) 132/33 kV, 1 X 20 MVA Transformer at Jiribam (PG) Sub-Station
3. Mizoram System is connected with the Main Grid through :-
a) 132 kV S/C Aizawl (PG) – Zemabawk line.
b) 132 kV S/C Aizawl (PG) – Longmol line.
c) 132 kV S/C Badarpur (PG) – Kolasib line.
d) 132 kV S/C Aizawl (PG) – Kolasib line.
4. Tripura System is connected with the Main Grid through :-
a) 132 kV D/C AGTPP (NEEPCO) – Agartala lines
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b) 132 kV S/C Kumarghat (PG) – P K Bari line
c) 132 kV S/C Dullavcherra (Assam) – Dharmanagar (Missiontila) line
5. South Assam is connected with the Main Grid through :-
a) 132 kV S/C Badarpur(PG) – Panchgram line.
b) 132 kV S/C Lumshnong (Meghalaya) – Panchgram line
c) 132 kV S/C Dharmanagar (Tripura) – Dullavcherra line.
d) 132 kV S/C Jiribam (PG) – Pailapool line.
e) 132 kV S/C Haflong (PG) – Haflong line.
f) 33 kV S/C Khandong (NEEPCO) – Umrangshu line.
6. Meghalaya system is connected with the Main Grid through :-
a) 132 kV S/C Panchgram(Assam) – Lumshnong line
b) 132 kV D/C Khliehriat(PG) – Khliehriat lines
c) 132 kV D/C Kahilipara(Assam) - Umtru lines
d) 132 kV D/C Sarusajai (Assam) – Umtru lines
7. The connectivity of the 132 kV System with 220 kV System & major
connectivity of intra 132 kV System :-
a. Dimapur (PG) Sub-Station is connected with Misa (PG) Sub-Station through
220 kV D/C Misa – Dimapur lines. 220 kV Bus of Dimapur (PG) Sub-Station
is connected to 132 kV Bus through 2X100 MVA ICT.
b. Dimapur (PG) Sub-Station is connected with Imphal (PG) Sub-Station
through 132 kV S/C Dimapur – Imphal line.
c. Imphal (PG) Sub-Station is connected with Loktak (NHPC) Power Station
through 132 kV S/C Imphal – Loktak line.
d. Loktak (NHPC) Power Station is connected with Jiribam (PG) Sub-Station
through 132 kV S/C Loktak – Jiribam line.
e. Jiribam (PG) Sub-Station is connected with Haflong (PG) Sub-Station,
Badarpur (PG) Sub-Station and Aizawl (PG) Sub-Station through 132 kV S/C
Jiribam – Haflong line, 132 kV S/C Jiribam – Badarpur line and 132 kV S/C
Jiribam – Aizawl line respectively.
f. Khandong (NEEPCO) Power Station is connected with Kopili (NEEPCO)
Power Station through 132 kV D/C Kopili – Khandong lines. 220 kV Bus of
Kopili Power Station is connected to 132 kV Bus through 1X160 MVA ICT.
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g. Khandong (NEEPCO) Power Station is connected with Khliehriat (PG) Sub-
Station and Haflong (PG) Sub-Station through 132 kV D/C Khandong –
Khliehriat lines and 132 kV S/C Khandong – Haflong line respectively.
h. Badarpur (PG) Sub-Station is connected with Khliehriat (PG) Sub-Station ,
Kumarghat (PG) Sub-Station, Jiribam (PG) Sub-Station and Aizawal (PG)
Sub-Station through 132 kV S/C Khliehriat – Badarpur line, 132 kV S/C
Kumarghat – Badarpur line, 132 kV S/C Badarpur – Jiribam line and 132
kV S/C Badarpur – Kolasib - Aizawl lines respectively.
i. Kumarghat (PG) Sub-Station is connected with AGTPP (NEEPCO) and
Aizawl (PG) Sub-Station through 132 kV S/C Kumarghat – AGTPP line and
132 kV S/C Kumargaht – Aizawl line respectively.
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CHAPTER 6
BLACK START & RESTORATION PROCEDURES
This Chapter explains broad guidelines for restoring the system after black out. The procedure
is split up for the following scenarios:-
1. Restoration of NER Grid after total collapse, when power from Eastern Region
(ER) is available
2. Restoration of NER Grid after total collapse, when power from Eastern Region
(ER) is not available
3. Restoration of 132 kV Network comprising of Nagaland, Manipur, South Assam,
Mizoram, Tripura and Meghalaya , after partial collapse.
4. Restoration of 132 kV Network comprising of Nagaland, Manipur (except Jiribam)
and Loktak , after partial collapse.
NER Grid under above scenarios will be restored after building up of some sub-systems /
islands on the basis of available resources. Source of start up power is to be identified whether
it is available within sub-system / island or outside the sub-system / island for early
restoration. The following procedure is to be adopted for restoration of affected system:-
I. Source of start up power
II. Identifying the critical / essential loads of each sub-system / island
III. Points of synchronization with other sub-system / island
IV. Action to be taken by various Generating Stations and Sub-Stations.
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6.1 Restoration of NER Grid after total collapse, when power from ER is
available
For restoration of NER Grid from total collapse condition, a multi pronged restoration
strategy is envisaged in which some sub-systems/islands are to be built up
simultaneously by utilizing power from Eastern Region (ER) and black start facilities
available in various Power Stations in North Eastern Region.
For restoration of NER Grid from total collapse condition, the following sub-systems
/ islands are to be built up in parallel:-
6.1.1 The system, consisting of the following sub-systems are to be
built up in parallel, by utilizing power from ER
Sub system #1 consisting of Bongaigaon, Salakati, Gelephu, Balipara, Ranganadi,
Ziro, Nirjuli, Itanagar, Gohpur, Pavoi, Depota, Rowta, Dhemaji,
North Lakhimpur, Majuli, Misa, Samaguri, Mariani, AGBPP,
Deomali, Dimapur , Doyang, Nagaland System & Kopili, Khandong,
Khliehriat (PG), Haflong, Badarpur, Panchgram and Kolasib.
Sub system #2 consisting of BTPS, Agia, Dhaligaon, Barnagar, Nalbari, Rangia,
Sipajhar, Sarusajai, Kahilipara and Langpi
6.1.2 Island consisting of NTPS, LTPS with Dibrugarh, Nazira and Tinsukia. (ISLAND B)
6.1.3 Island consisting of Meghalaya System. (ISLAND C) 6.1.4 Island consisting of AGTPP, Tripura, Mizoram and
Dullavcherra. (ISLAND D) 6.1.5 Island consisting of Loktak, Manipur and Pailapool. (ISLAND
E)
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6.1.1 Restoration of systems to be built up by utilizing power from ER
Sub-system #1 and sub-system #2 shall to be restored in parallel after taking
power from Eastern Region. Simultaneously, all the generating Stations which
have black-start facilities are advised to bring their units as fast as possible, so
that, islands can be formed for early restoration of the system
6.1.1.1 Restoration of sub-system #1
This sub-system consists of Bongaigaon, Salakati, Gelephu, Balipara,
Ranganadi, Ziro, Nirjuli, Itanagar, Gohpur, Pavoi, Depota, Rowta, North
Lakhimpur, Dhemaji, Majuli, Misa, Samaguri, Mariani, AGBPP, Deomali,
Dimapur , Doyang, Nagaland System & Kopili, Khandong, Khliehriat (PG),
Haflong, Badarpur, Panchgram and Kolasib. Restoration procedure of this
sub-system is as follow:-
1) Power required for this sub system shall be taken from New Siliguri (ER)
Sub-Station to Bongaigaon (NER) Sub-Station through any one of 400 kV
D/C New Siliguri – Bongaigaon lines.
2) In case of delay in receiving power from New Siliguri (ER) Sub-Station,
then the following procedure shall be adopted :-
Salakati (NER) Sub-Station shall receive power from Birpara (ER) Sub-
Station through any one of 220 kV D/C Birpara – Salakati lines. Any one of
400 kV Bus(s) at Bongaigaon Sub-Station shall be charged through 315
MVA ICT at Bongaigaon Sub-Station. Again, Salakati Sub-Station shall
charge any one of 220 / 132 kV , 50 MVA ICT & shall extend power to
Gelephu through 132 kV S/C Saklakati – Gelephu line.Load at Gelephu
can be connected in co-ordination with NLDC & Bhutan.
Bus Reactors (at Annex III) at New Siliguri Sub-Station and Bongaigaon
Sub-Station shall be taken into service to contain voltage. Bongaigaon (PG)
Sub-Station shall extend power to Balipara (PG) Sub-Station through any
one of 400 kV D/C Balipara – Bongaigaon lines. Any one of 220 kV Bus(s)
at Salakati Sub-Station shall be charged through 315 MVA ICT at
Bongaigaon Sub-Station. If required, Tertiary Reactor at Bongaigaon (at
Annex III) may be taken into service to contain voltage.
3) Balipara (PG) Sub-Station shall extend power to Misa (PG) Sub-Station
through any one of 400 kV D/C Balipara – Misa lines and Shunt Reactors
(at Annex III) at Balipara and Misa Sub-Stations shall be taken into service
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to contain voltage. Any one of 220 kV Bus(s) at Balipara Sub-Station shall
be charged through 315 MVA ICT at Balipara Sub-Station. If required,
Tertiary Reactor at Balipara (at Annex III) may be taken into service to
contain voltage. 132 kV Bus at Balipara Sub-Station shall be charged
through 2X50 MVA ICT at Balipara Sub-Station. Balipara Sub-Station shall
extend power to Khupi & Kimi Sub-Stations through 132 kV Balipara –
Khupi - Kimi lines. Load at Khupi & Kimi shall be connected in co-
ordination with SLDC, Arunachal Pradesh.
4) Ranganadi (NEEPCO) Power Station can receive power from Balipara (PG)
Sub-Station through any one of 400 kV D/C Balipara – Ranganadi lines.
Any one of 132 kV Bus(s) at Ranganadi Power Station shall be charged
through any one of 2X360 MVA ICT at Ranganadi Power Station.
Ranganadi (NEEPCO) Power Station shall extend power to SMS
(Arunachal Pradesh) and Nirjuli (PG) Sub-Stations through 132 kV S/C
Ranganadi – SMS - Nirjuli (T Connection at SMS) and shall extend power
to Daporijo and Along (Arunachal Pradesh) Sub-Stations through 132 kV
S/C Ranganadi – Ziro - Daporijo– Along lines. Shunt Reactors (at Annex
III) at Ranganadi Power Station shall be taken into service to contain
voltage. Load shall be connected at SMS, Ziro, Daporijo and Along in co-
ordination with SLDC, Arunachal Pradesh.
5) 33 kV Bus at Nirjuli Sub-Station shall be charged through any one of
1X10+1X16 MVA ICT at Nirjuli Sub-Station. Nirjuli Sub-Station shall
extend power to Itanagar (Arunachal Pradesh) Sub-Station through any one
of four nos of 33 kV feeders. Itanagar Sub-Station can also receive power
from SMS Sub-Station through Naharlagun (Arunachal Pradesh) Sub-
Station. Load shall be connected at Itanagar in co-ordination with SLDC,
Arunachal Pradesh.
6) Balipara (PG) Sub-Station shall also extend power to Gohpur (Assam) Sub-
Station through 132 kV S/C Balipara – Gohpur line. Gohpur Sub-Station
can also receive power from Samaguri and Depota Sub-Stations through
132 kV Samaguri – Pavoi (Bishwanath Chariali) - Gohpur line and 132 kV
Depota – Pavoi (Bishwanath Chariali) – Gohpur line respectively. Load
shall be connected at Gohpur in co-ordination with SLDC, Assam. Balipara
(PG) Sub-Station shall extend power to Depota Sub-Station through 132 kV
Balipara – Depota line. Load at Depota shall be connected in co-ordination
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with SLDC, Assam. Depota Sub-Station shall extend power to Rowta Sub-
Station through 132 kV Depota – Rowta line. Load at Rowta shall be
connected in co-ordination with SLDC, Assam.
7) Gohpur (Assam) Sub-Station shall extend power to North Lakhimpur,
Dhemaji and Majuli Sub-Stations. Loads at North Lakhimpur, Dhemaji and
Majuli shall be connected in co-ordination with SLDC, Assam.
8) Ranganadi (NEEPCO) Power Station shall bring their machines if required
and synchronize with this sub-system. Otherwise, if the power received
from Balipara Sub-Station is delayed, Ranganadi Power Station shall black
start one of their three units and shall charge 132 kV Bus and extend power
to SMS, Nirjuli & Ziro Sub-Stations and wait for extension of power from
Balipara Sub-Stations. If possible they can also charge one circuit of 400 kV
D/C Ranganadi – Balipara line for synchronization.
9) Gohpur Sub-Station can also receive power from Nirjuli (PG) Sub-Station
through 132 kV Nirjuli – Gohpur line.
Note : SLDC, Assam and Arunachal Pradesh shall co-ordinate with
NERLDC before connecting loads to their systems.
10) Any one of 220 kV Bus(s) at Misa Sub-Station shall also be charged
through 315 MVA ICT at Misa Sub-Station after receiving power from
Balipara (PG) Sub-Station. If required, Tertiary Reactor at Misa (at Annex
III) may be taken into service to contain voltage.
11) Misa Sub-Station shall extend power to Samaguri (Assam) Sub-Station
through any one of 220 kV D/C Misa – Samaguri lines. Shunt Reactors (at
Annex III) at Samaguri Sub-Station shall be taken into service to contain
voltage. 132 kV Bus at Samaguri Sub-Station may be charged through any
one of 3X50 MVA ICT. Load at Samaguri shall be connected in co-
ordination with SLDC, Assam.
12) Misa Sub-Station shall extend power to Byrnihat (Meghalaya) Sub-Station
through any one of 220 kV D/C Misa – Killing (Byrnihat) lines. 132 kV Bus
at Byrnihat Sub-Station shall be charged through any one of 2X160 MVA
ICT. Byrnihat Sub-Station shall extend power to EPIP II Sub-Station
through any one of 132 kV D/C Byrnihat – EPIP II lines. Load at EPIP II
shall be connected in co-ordination with SLDC, Meghalaya. EPIP II Sub-
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Station shall extend power to EPIP I Sub-Station through any one of 132 kV
D/C EPIP II – EPIP I lines. Load at EPIP I shall be connected in co-
ordination with SLDC, Meghalaya. 13) Mariani (Assam) Sub-Station can receive power either from Misa Sub-
Station through 400 kV S/C Misa – Mariani line (Charged at 220 kV) or
Samaguri (Assam) Sub-Station through 220 kV S/C Samaguri – Mariani
line (presently one circuit is available). Shunt Reactors (at Annex III) at
Mariani Sub-Station shall be taken into service to contain voltage. Load at
Mariani shall be connected in co-ordination with SLDC, Assam.
14) Kopili (NEEPCO) Power Station shall receive power from Misa Sub-
Station through any one of 220 kV T/C Misa – Kopili lines. Kopili Power
Station shall bring their machines by taking start up power from this sub-
system and synchronize the machines with this sub-system. Otherwise, if the
power received from Misa Sub-Station is delayed, Kopili Power Station
shall black start one of four units and shall charge 220 kV Bus and extend
power to Khandong Power Station and wait for extension of power from
Misa Sub-Stations.
15) 132 kV Bus at Kopili Power Station shall be charged through 160 MVA
ICT at Kopili Power Station.
16) Kopili Power Station shall extend power to Khandong (NEEPCO) Power
Station through any one of 132 kV D/C Kopili – Khandong lines. Khandong
Power Station shall bring machines, if required, by taking start up power
from this sub-system and synchronize the machines with this sub-system.
Otherwise, if the power received from Kopili Power Station is delayed,
Khnadong Power Station shall black start one of three units and shall charge
132 kV Bus and extend power to Haflong & Khliehriat Sub-Stations and
wait for extension of power from Kopili Power Station. If possible, they can
also charge one circuit of 132 kV D/C Kopili – Khandong lines for
synchronization.
17) Khandong Power Station shall charge 33 kV Bus through any one of
1X16+1X7.5 MVA Transformer. Khandong shall extend power to
Umrangshoo Sub-Station through 33 kV S/C of Khandong – Umrangshoo
line. Load at Umrangsho shall be connected in co-ordination with SLDC,
Assam.
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18) Khandong Power Station shall extend power to Khliehriat (PG) and
Haflong (PG) Sub-Stations through any one of 132 kV D/C of Khandong –
Khliehriat lines and 132 kV S/C Khandong – Haflong line respectively.
19) Khliehriat (PG) Power Station shall extend power to Badarpur (PG) Sub-
Station through 132 kV S/C Khliehriat- Badarpur line.
20) Badarpur Sub-Station shall extend power to Panchgram (Assam) Sub-
Station through 132 kV S/C Badarpur – Panchgram line. Panchgram Sub-
Station shall extend power to Sreekona Sub-Station through 132 kV
Panchgram – Sreekona line. Load at Panchgram and Sreekona shall be
connected in co-ordination with SLDC, Assam.
21) This sub-system shall be synchronized with Island D at Badarpur (PG)
through 132 kV S/C Badapur – Kumarghat line. This sub-system shall be
also synchronized with Island D at Badarpur (PG) through 132 kV
Dullavcherra – Panchgram – Badarpur line.
22) This sub-system shall be synchronized with Island E at Badarpur (PG)
through 132 kV S/C Badapur – Jiribam line.
23) This sub-system shall be synchronized with Island C at Khliehriat (PG)
through 132 kV D/C Khliehriat – Khliehriat lines.
24) Badarpur Sub-Station shall extend power to Kolasib (Mizoram) Sub-Station
through 132 kV S/C Badarpur – Kolasib line. Load at Kolasib shall be
connected in co-ordination with SLDC, Mizoram.
25) Kolasib Sub-Station shall extend power to Bairabi (Mizoram) Power
Station for survival/auxiliary power through 66 kV Kolasib – Bairabi line.
26) Haflong (PG) Sub-Station shall extend power to Haflong (Assam) Sub-
Station through 132 kV S/C Haflong – Haflong line. Load at Haflong shall
be connected in co-ordination with SLDC, Assam.
27) Mariani Sub-Station shall extend power to AGBPP (NEEPCO) through 400
kV S/C Mariani – AGBPP line (charged at 220 kV). AGBPP shall bring
their machines by taking start up power from this sub-system and
synchronize the machines with this sub-system. AGBPP shall extend power
to Deomali (Arunachal Pradesh) Sub-station through 220 kV S/C AGBPP –
Deomali line. Load at Deomali shall be connected in co-ordination with
SLDC, Arunachal Pradesh.
28) Misa (PG) Sub-Station shall extend power to Dimapur (PG) Sub-station
through any one of 220 kV D/C Misa – Dimapur lines. 132 kV Bus at
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Dimapur Sub-Station shall be charged through any one of 2X100 MVA ICT
at Dimapur.
29) Dimapur (PG) Sub-Station shall extend power to Dimapur (Nagaland) Sub-
Station through any one of 132 kV D/C Dimapur – Dimapur line. Load at
Dimapur shall be connected in co-ordination with SLDC, Nagaland.
30) Dimapur (PG) Sub-station shall extend power to Kohima Sub-Station
through 132 kV S/C Dimapur – Kohima line. Load at Kohima shall be
connected in co-ordination with SLDC, Nagaland.
31) Kohima Sub-station shall extend power to Meluri Sub-Station through 132
kV S/C Kohima – Meluri line. Load at Meluri shall be connected in co-
ordination with SLDC, Nagaland.
32) Meluri Sub-Station shall extend power to Khiphire Sub-Station through 132
kV S/C Meluri – Khiphire line. Load at Khiphire shall be connected in co-
ordination with SLDC, Nagaland.
33) 66 kV Bus at Khiphire Sub-Station shall be charged through any one of
3X6.5 MVA ICT at Khiphire Sub-Station.
34) Khiphire Sub-Station shall extend power to Likhimro Power Station
through 66 kV Khiphire – Likhimro line.
35) Dimapur (PG) Sub-Station shall also extend power to Doyang (NEEPCO)
Power Station through any one of 132 kV D/C Dimapur – Doyang lines.
Doyang Power Station shall bring generation, if required and synchronize.
Otherwise, if the power received from Dimapur Sub-Station is delayed,
Doyang Power Station shall black start one of three units & shall charge 132
kV bus and extend power to Mokakchung Sub-Station.
36) Doyang (NEEPCO) Power Station shall extend power to Mokokchung Sub-
Station through 132 kV S/C Doyang – Mokukchung line. Load at
Mokokchung shall be connected in co-ordination with SLDC, Nagaland.
37) This sub-system may also be synchronized with Island E at Dimapur (PG)
through 132 kV S/C Dimapur – Imphal line.
38) Dimapur (PG) Sub-Station can also receive power form Mariani Sub-
Station through 132 kV S/C Mariani – Golaghat – Bokajan - Dimapur line.
39) Mokokchung Sub-Station can also receive power from Mariani Sub-Station
through 132 kV S/C Mariani – Mokokchung line. Presently 132 kV S/C
Mariani – Mokokchung line is under long outage. Early restoration of this
line will help to extend power to Mokokchung.
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Note : SLDC, Assam and Nagaland shall co-ordinate with NERLDC
before connecting loads to their system
NOTE: If ER power received by Misa Sub-Station is delayed then power shall be
taken from the following sources:-
i. From Island C, Khliehriat (PG) Sub-Station can receive power from
Khliehriat (Meghalaya) Sub-Station through any one of 132 kV D/C
Khliehriat – Khliehriat lines.
ii. From Island C, Panchgram (Assam) Sub-Station can receive power from
Khliehriat (Meghalaya) Sub-Station through 132 kV S/C Khliehriat –
Lumnsnong - Panchgram line.
iii. From Island D, Badarpur (PG) Sub-Station can receive power from
Kumarghat Sub-Station through 132 kV S/C Badarpur – Kumarghat line.
iv. From Island D, Kolasib Sub-Station can receive power from Aizawl Sub-
Station through 132 kV S/C Kolasib – Aizawl line
v. From Island D, Panchgram (Assam) Sub-Station can receive power from
Dharmanagar Sub-Station through 132 kV S/C Dharmanagar -
Dullavcherra - Panchgram line.
vi. From Island E, Haflong (PG) Sub-Station can receive power from Jiribam
Sub-Station through 132 kV S/C Haflong – Jiribam line.
vii. From Island E, Dimapur (PG) Sub-Station can receive power from
Imphal(PG) Sub-Station through 132 kV S/C Imphal - Dimapur line.
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Sub-system#1
Page 35 of 74
6.1.1.2 Restoration of sub-system #2
This sub-system consists of BTPS, Agia, Dhaligaon, Barnagar, Nalbari,
Rangia, Sipajhar, Sarusajai, Kahilipara and Langpi. Restoration
procedure for this sub-system is as follow :-
1) From sub-system #1, Salakati (PG) Sub-Station shall extend power to BTPS
(Assam) Sub-Station through any one of 220 kV D/C Salakati – BTPS lines.
2) BTPS Sub-Station shall extend power to Agia (Assam) Sub-Station through
220 kV BTPS – Agia line. Presently one circuit of 220 kV BTPS – Agia is
available. Load at Agia shall be connected in co-ordination with SLDC,
Assam.
3) 132 kV Bus at BTPS Sub-Station shall be charged through any one of
2X80+1X160 MVA ICT at BTPS Sub-Station. BTPS Sub-Station shall
extend power to Dhaligaon (Assam) Sub-Station through any one of 132 kV
D/C BTPS – Dhaligaon lines. Load at Dhaligaon shall be connected in co-
ordination with SLDC, Assam.
4) Dhaligaon Sub-Station shall extend power to Rangia (Assam) Sub-Station
and Barnagar (Assam) Sub-Station through 132 kV Dhaligaon – Barnagar
and 132 kV Dhaligaon –Nalbari - Rangia lines. Load at Nalbari, Rangia and
Barnagar shall be connected in co-ordination with SLDC, Assam. 132 kV
S/C Rangia – Barnagar line shall be closed.
5) Again, Rangia shall extend power to Motonga (Bhutan) through 132 kV
Rangia – Motonga line. Gelephu can also receive power through Motonga.
6) Rangia Sub-Station shall extend power Sisugram (Assam) Sub-Station
through 132 kV S/C Rangia – Sishugram line. Load at Sishugram shall be
connected. If required, Rangia Sub-Station shall extend power to Rowta
Sub-Station too through 132 kV Rangia – Sipajhar - Rowta & 132 kV
Rangia – Rowta line. Load at Sipajhar & Rowta may be connected in co-
ordination with SLDC, Assam.
7) Agia (Assam) Sub-Station shall extend power to Sarusajai (Assam) Sub-
Station through 220 kV S/C Agia – Sarusajai or 220 kV Agia – Boko –
Sarusajai lines. 132 kV Bus at Sarusajai Sub-Station shall be charged
through any one of 3X100 MVA ICT at Sarusajai. Load at Sarusajai &
Boko shall be connected in co-ordination with SLDC, Assam.
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8) Sarusajai Sub-Station shall extend power to Kahilipara (Assam) Sub-Station
through any one line of four nos. of 132 kV Sarusajai – Kahilipara lines.
Load at Kahilipara shall be connected in co-ordination with SLDC, Assam.
9) Sarusajai Sub-Station shall extend power to Langpi (Assam) Power Station
through any one of 220 kV D/C Sarusajai – Langpi lines.
10) Kahilipara Sub-Station can also receive power from Rangia and Sisugram
Sub-Stations through 132 kV S/C Rangia – Kahilipara line and 132 kV S/C
Sisugram – Kahilipara line respectively.
11) Sarusajai Sub-Station can also receive power from Samaguri Sub-Station of
sub-system #1 through any one of 220 kV D/C Sarusajai – Samaguri lines.
Remark : SLDC, Assam shall co-ordinate with NERLDC before
connecting loads.
Note : If ER power received by this system is delayed then power shall be taken
from the following sources :-
i. From Island C, Sarusajai Sub-Station can receive power from Umtru
(Meghalaya) Power Station through any one of 132 kV D/C Umtru -
Sarusajai lines.
ii. From Island C, Kahilipara Sub-Station can receive power from Umtru
(Meghalaya) Power Station through any one 132 kV D/C Umtru -
Kahilipara lines.
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Sub-system #2
Page 38 of 74
6.1.2 Restoration of Island B
This Island consists of NTPS, LTPS with Dibrugarh, Nazira and Tinsukia. Restoration procedure of this Island by its own black-start facility is as follow
1) NTPS (Assam) shall black-start and charge 66 kV Bus at NTPS. Load at NTPS
shall be connected in co-ordination with SLDC Assam. NTPS shall bring and
synchronize other units.
2) NTPS shall extend power to LTPS (Assam) through any one of 132 kV D/C
LTPS – NTPS lines. LTPS shall bring generation and synchronize.
3) NTPS shall extend power to Tinsukia & Nazira (Assam) Sub-Stations through
any one of 66 kV D/C NTPS – Tinsukia and any one of 66 kV D/C NTPS –
Nazira lines respectively. Load at Tinsukia and Nazira shall be connected in co-
ordination with SLDC Assam.
4) 132 kV Bus at NTPS shall be charged through any one of 2X25 MVA ICT at
NTPS.
5) NTPS shall also extend power to Tinsukia (Assam) Sub-Station through 132 kV
S/C NTPS -Tinsukia line.
6) LTPS shall extend power to Dibrugarh (Assam) Sub-Stations through 132 kV
S/C LTPS – Dibrugrah and 132 kV S/C LTPS - Nazira line. Load at Dibrugarh
shall be connected in co-ordination with SLDC Assam. 132 kV LTPS – Nazira
line shall be closed.
7) This island shall be synchronized with sub-system #1 at Mariani (Assam)
through 132 kV S/C LTPS – Mariani line.
Note: If Black start by NTPS is not possible, then start up power for this Island
shall be received from the following sources:-
i. From sub system #1, Tinsukia Sub-Station can receive power from
AGBPP through any one of 220 kV D/C Tinsukia – AGBPP line and
shall extend start up power to NTPS through 132 kV S/C Tinsukia –
NTPS line.
ii. From sub system #1, LTPS can receive power from Mariani Sub-Station
through 132 kV S/C Mariani – LTPS line.
Note : LTPS shall explore their black start facility
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ISLAND B
Page 40 of 74
6.1.3 Restoration of Island C
This Island consists of Meghalaya System. Meghalaya system can be built up
by its own black-start facilities. Restoration procedure for this Island is as
follow :-
1) Umiam St I Power Station shall black-start and charge 132 kV Bus at Umiam St
I Power Station. Umiam St III Power Station shall also black start and
charge132 kV Bus at Umiam St III Power Station.
2) Umiam St I Power Station shall synchronize with Umiam St III Power Station at
Umium St III Power Station through any one of 132 kV D/C Umiam St I –
Umiam St III lines. Umiam St I & III Power Stations shall bring and
synchronize other machines. Load at Umiam St III shall be connected in co-
ordination with SLDC Meghalaya.
3) Umiam St I Power Station shall extend power to Umiam St II Power Station
through 132 kV S/C Umiam St I – Umiam II line for survival/auxiliary power.
Umiam St II Power Station shall bring generation if required and synchronize.
4) Umiam St III Power Station shall extend power to Umiam St IV Power Station
through any one of 132 kV D/C Umiam St III – Umiam IV line for
survival/auxiliary power. Umiam St IV Power Station shall bring generation if
required and synchronize.
5) Umiam St III Power Station shall extend power to Umtru Power Station through
any one of 132 kV D/C Umiam St III – Umtru lines. Load at Umtru shall be
connected in co-ordination with SLDC Meghalaya. Umtru Power Station shall
bring generation if required and synchronize.
6) Umiam St I Power Station shall extend power to Mawlai and NEHU Sub-
Stations through 132 kV S/C Umiam St I – Mawlai line and 132 kV S/C Umiam
St I – Umiam - NEHU line respectively. Load at Mawlai, Umiam and NEHU
shall be connected in co-ordination with SLDC Meghalaya.
7) NEHU Sub-Station shall extend power to Khliehriat Sub-Station through 132
kV S/C NEHU – NEIGRIHMS - Khliehriat line or 132 kV NEHU – Khliehriat
line. Load at Khliehriat and NEIGRIHMS shall be connected in co-ordination
with SLDC Meghalaya.
8) Khliehriat Sub-Station shall extend power to Lumsnong Sub-Station through
132 kV S/C Khliehriat- Lumsnong line.Load at Lumsnong shall be connected in
co-ordination with SLDC Meghalaya.
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9) Again , Power shall be extended to Leshka power station from Khliehriat
(Meghalaya) Sub-Station through 132 kV D/C Khliehriat – Leshka lines.
10) This island shall be synchronized with sub-system #2 at Sarusajai (Assam)
Sub-Station and Kahilipara (Assam) Sub-Station through any one of 132 kV
D/C Umtru – Sarusajai lines or through any one of 132 kV D/C Umtru –
Kahilipara lines.
11) This island shall be synchronized with sub-system #1 at Khliehriat (PG) Sub-
Station through any one of 132 kV D/C Khliehriat – Khliehriat lines.
Note: If Black Start by Meghalaya Power Stations is not possible then start up
power for this Island shall be received from the following sources :-
i. From sub-system#1, Khliehriat (Meghalaya) Sub-Station can receive
power from Khliehriat (PG) Sub-Station through any one of 132 kV D/C
Khliehriat – Khliehriat lines and extend power to Umiam St I and
Leshka Power Station through NEHU & Umiam Sub-Stations and 132
kV D/C Khliehriat – Leshka lines respectively, for brining generation.
ii. From Sub System #1, Khliehriat (Meghalaya) Sub-Station can receive
power from Panchgram (Assam) Sub-Station through 132 kV
Panchgram - Lumsnong – Khliehriat line.
iii. From Sub System #2, Umtru (Meghalaya) Sub-System can receive
power from Sarusajai (Assam) Sub-Station through any one of 132 kV
D/C Sarusajai – Umtru lines and extend power to Umiam St III Power
Station through any one of 132 kV D/C Umiam St III - Umtru for
brining generation.
iv. From Sub System #2, Umtru (Meghalaya) Sub-Station can receive
power from Kahilipara (Assam) Sub-Station through any one of 132 kV
D/C Kahilipara – Umtru lines and extend power to Umiam St III Power
Station through any one of 132 kV D/C Umiam St III - Umtru for
brining generation.
v. From Sub System #1, Umtru (Meghalaya) Sub-Station can receive
power from Killing (Meghalaya) Sub-Station through 132 kV D/C
Killing–EPIPII–Umtru
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ISLAND C
Page 43 of 74
6.1.4 Restoration of Island D :
This Island consists of AGTPP, Tripura, Mizoram and Dullavcherra. AGTPP
and Tripura System can restore its system by their own black start facilities.
Restoration procedure for this Island is as follow :-
1) Rokhia (Tripura) Power Station shall black start and charge 66 kV Bus at
Rokhia Power Station. Load at Rokhia shall be connected in co-ordination with
SLDC, Tripura. Rokhia Power Station shall bring and synchronize other
machines.
2) 132 kV Bus at Rokhia Power Station shall be charged through 30 MVA ICT at
Rokhia Power Station.
3) Rokhia Power Station shall extend power to Agartala Sub-Station through any
one of 132 kV D/C Rokhia – Agartala lines. Load at Agartala shall be connected
in co-ordination with SLDC, Tripura.
4) AGTPP (NEEPCO) shall black start one of its unit and charge 132 kV Bus at
AGTPP. AGTPP shall synchronize Tripura System through any one of 132 kV
D/C AGTPP – Agartala lines. AGTPP shall bring and synchronize other
machines.
5) Agartala Sub-Station shall extend power to Baramura Power Station through
132 kV S/C Agartala – Budhjangnagar – Jirania - Baramura lines. Baramura
Power Station shall bring generation and synchronize with this Island.
6) Rokhia Power Station shall extend power to Udaipur Sub-Station through 132
kV S/C Rokhia – Udaipur line.
7) 66 kV Bus at Udaipur Sub-Station shall be charged through 15 MVA ICT at
Udaipur Sub-Station. Load at Udaipur shall be connected in co-ordination with
SLDC, Tripura.
8) Udaipur Sub-Station shall extend power to Gumti Power Station through 66 kV
S/C Udaipur – Gumti line.
9) Gumti Power Station shall bring generation if required and synchronize with
this Island.
10) Agartala Sub-Station shall extend power to Dhalabil Sub-Station through 132
kV S/C Agartala – Dhalabil line. Load at Dhalabil shall be connected in co-
ordination with SLDC, Tripura.
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11) Dhalabil Sub-Station shall extend power to Kamalpur Sub-Station through 132
kV S/C Dhalabil –Kamalpur line. Load at Kamalpur shall be connected in co-
ordination with SLDC, Tripura.
12) Kamalpur Sub-Station shall extend power to P K Bari Sub-Station through 132
kV S/C Kamalpur – P K Bari line. Load at P K Bari shall be connected in co-
ordination with SLDC, Tripura.
13) P K Bari Sub-Station shall extend power to Dharmanagar Sub-Station through
132 kV S/C P K Bari – Dharmanagar line. Load at Dharmanagar shall be
connected in co-ordination with SLDC, Tripura.
14) Dharmanagar Sub-Station shall extend power to Dullavcherra (Assam) Sub-
Station through 132 kV S/C Dharmanagar – Dullavcherra line. Dullavchera
shall extend start up power to Adamtila. Load at Dullavcherra shall be
connected in co-ordination with SLDC, Assam.
15) P K Bari Sub-Station shall extend power to Kumarghat Sub-Station through
132 kV S/C P K Bari – Kumarghat line.
16) AGTPP shall extend power to Kumarghat Sub-Station through 132 kV S/C
AGTPP – Kumarghat line.
17) Kumarghat Sub-Station shall extend power to Aizawl Sub-Station through 132
kV S/C Kumarghat – Aizawl line.
18) Aizawl (PG) Sub-Station shall extend power to Zimabawk & Longmol
(Mizoram) Sub-Station through 132 kV S/C Aizawl – Zimabawk & 132 kV
Aizawl – Longmol lines. Load at Zimabawk & Longmol (Mizoram) shall be
connected in co-ordination with SLDC, Mizoram.
19) P K Bari Sub-Station shall extend power to Kailashar Sub-Station through 132
kV S/C P K Bari – Kailashar line. Load at Kailashar shall be connected in co-
ordination with SLDC, Agartala.
20) P K Bari Sub-Station shall extend power to Ambassa Sub-Station through 132
kV S/C P K Bari – Ambassa line. Load at Ambassa shall be connected in co-
ordination with SLDC, Agartala. 132 kV Baramura – Gamaitila - Ambassa lines
shall be closed.
21) If required, Bus Reactor (Annex III) at Kumarghat and Aizawl Sub-Stations
shall be taken into service to contain voltage.
22) This island may be synchronized with sub-system#1 at Aizwal (PG) through
132 kV S/C Kolasib – Aizwal line
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23) This island shall be synchronized with Island E at Aizwal (PG) through 132 kV
S/C Jiribam – Aizwal line.
24) This island may be synchronized with sub-system#1 at Badarpur (PG) through
132 kV S/C Dullavchera – Panchgram - Badarpur line.
Note : SLDC, Tripura and Mizoram shall co-ordinate with NERLDC
before connecting loads.
Note : If Black start of this Island is not possible then power shall be received from
the following sources:-
i. From sub system #1, Kumarghat Sub-Station can receive power from
Badarpur (PG) through 132 kV S/C Badarpur – Kumarghat line. Start
up power for bringing machines of AGTPP can receive power from
Kumarghat Sub-Station through 132 kV Kumarghat – AGTPP line.
ii. From sub system#1, Aizawl (PG) Sub-Station can receive power from
Kolasib Sub-Station through 132 kV S/C Aizawl – Kolasib line.
iii. From sub system#1, Dullavcheral (Assam) Sub-Station can receive
power from Panchgram (Assam) Sub-Station through 132 kV S/C
Panchgram - Dullavchera line.
iv. From Island E, Aizawl Sub-Station can receive power from Jiribam
(PG) Sub-Station through 132 kV S/C Jiribam – Aizawl line.
Page 46 of 74
ISLAND D
Page 47 of 74
6.1.5 Restoration of Island E:
This Island consists of Loktak, Manipur and Pailapool. Restoration procedure
for this Island is as follow :-
i) Loktak (NHPC) Power Station shall black start and charge 132 kV Bus.
ii) Loktak Power Station shall extend power to Imphal (PG) and Ningthoukong
Sub-Stations through 132 kV S/C Loktak – Imphal and 132 kV S/C Loktak –
Ninghthoukong lines respectively. Load at Ningthoukong shall be connected in
co-ordination with SLDC, Manipur. Loktak Power Station shall bring and
synchronize other machines.
iii) Imphal (PG) Sub-Station shall extend power to Imphal (Manipur) Sub-Station
through 132 kV S/C Imphal – Imphal line. Load at Imphal (Manipur) shall be
connected in co-ordination with SLDC, Manipur.
iv) Ningthoukong Sub-Station shall extend power to Churachandpur Sub-Stations
through 132 kV S/C Ningthoukong – Churachandpur line. Load at
Churachandpur shall be connected in co-ordination with SLDC, Manipur. 132
kV S/C Ningthoukong – Imphal (Manipur) lines shall be closed.
v) Imphal (Manipur) Sub-Station shall extend power to Karong and Yangangpokpi
(Manipur) Sub-Stations through 132 kV S/C Imphal – Karong line and 132 kV
S/C Imphal – Yangangpokpi lines. Load at Karong and Yangangpokpi shall be
connected in co-ordination with SLDC, Manipur.
vi) Loktak Power Station shall extend power to Jiribam (PG) & Rengpang
(Manipur) Sub-Station through 132 kV S/C Loktak – Jiribam and 132 kV S/C
Loktak – Rengpang lines respectively. Load at Rengpang shall be connected in
co-ordination with SLDC, Manipur.
vii) Jiribam (PG) Sub-Station shall extend power to Pailapool ( Assam) Sub-Station
through 132 kV S/C Jiribam – Pailapool line. Load at Pailapool shall be
connected in co-ordination with SLDC, Assam and start up power to be
extended to Baskandi Power Station for bringing of their machines.
viii) 33 kV Bus at Jiribam (PG) Sub-Station shall be charged through 1X20 MVA
ICT at Jiribam (PG) Sub-Station. Load at Jiribam shall be connected in co-
ordination with SLDC, Manipur.
ix) This island shall be synchronized with sub-system #1 at Haflong (PG) Sub-
station through 132 kV S/C Haflong – Jiribam line.
x) This island shall be synchronized with sub-system #1 either at Imphal(PG) or
Dimapur (PG) Sub-Station through 132 kV S/C Dimapur - Imphal line.
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Note: SLDC, Assam and Manipur shall co-ordinate with NERLDC before
connecting loads.
Note: If Black start at Loktak Power Station is not possible then power shall be
received from the following sources:-
i. From sub system #1, Imphal (PG) Sub-Station can receive power from
Dimapur Sub-Station through 132 kV S/C Dimapur – Imphal line.
Imphal Sub-Station shall extend power to Loktak Power Station through
132 kV S/C Imphal - Loktak line.
ii. From sub system #1, Jiribam Sub-Station can receive power from
Badarpur Sub-Station through 132 kV S/C Jiribam – Badarpur line.
iii. From sub system #1, Jiribam Sub-Station can receive power Haflong
Sub-Station through 132 kV S/C Jiribam – Haflong line.
iv. From Island D, Jiribam Sub-Station can receive power Aizawl (PG)
Sub-Station through 132 kV S/C Jiribam – Aizawl line.
By the above procedures NER Grid can be restored fully
from the total collapsed condition, after utilizing ER power
as well as black start facilities available in various power
stations in NER. After building up of NER Grid, balance
elements shall be restored at the earliest.
Page 49 of 74
ISLAND E
Page 50 of 74
6.2 Restoration of NER Grid after total collapse, when power from ER is
not available
For restoration of NER Grid from total collapse condition, when power from ER is
not available, the following Islands are to be built up simultaneously, by utilizing
available Black start facilities.
F. Island consisting of Tripura, AGTPP, Kumarghat, Mizoram System,
Badarpur, Panchgram, Khliehriat, Khandong, Kopili, Haflong, Misa and
Samaguri
G. Island consisting of Loktak, Manipur, Jiribam, Pailapool, Imphal,
Dimapur, Doyang and Nagaland
H. Island consisting of NTPS , LTPS , Mariani, Dibrugarh and Tinsukia
I. Island consisting of Meghalaya with Kahilipara and Sarusajai
Page 51 of 74
6.2.1 Restoration of Island F
This Island consists of Tripura, AGTPP, Kumarghat, Mizoram System,
Badarpur, Panchgram, Khliehriat, Khandong, Kopili, Haflong, Misa and
Samaguri . The restoration of this Island is the same as the procedure followed
for Island D as well as the following procedures:-
1) Khandong (NEEPCO) Power Station shall black start one of three machines &
charge 132 kV Bus. Khandong Power Station shall charge 33 kV Bus through
any one of 1X16+1X7.5 MVA Transformers. Khandong shall extend power to
Umrangshoo (Assam) Sub-Station through 33 kV S/C of Khandong –
Umrangshoo line. Load at Umrangsho shall be connected in co-ordination with
SLDC, Assam.
2) Khandong Power Station shall extend power to Haflong (PG) Sub-Stations
through 132 kV Khandong – Haflong line.
3) Haflong (PG) Sub-Station shall extend power to Haflong (Assam) Sub-Stations
through 132 kV Haflong (PG) – Haflong (Assam) line. Load at Haflong shall be
connected in co-ordination with SLDC, Assam (Formation of Island Khandong)
4) Kumarghat (PG) Sub-Station shall extend power to Badarpur (PG) Sub-Station
through 132 kV S/C Kumarghat - Badarpur line.
5) Badarpur Sub-Station shall extend power to Panchgram (Assam) Sub-Station
through 132 kV S/C Badarpur – Panchgram line. Again, Panchgram Sub-Station
can also receive power from Dullavcherra Sub-station through 132 kV S/C
Dullavcherra – Panchgram line. Then, Panchgram Sub-Station can extend
power to Badarpur (PG) through 132 kV Panchgram – Badarpur line.
6) Panchgram Sub-Station shall extend power to Sreekona (Assam) Sub-Station
through 132 kV S/C Panchgram – Sreekona line. Load at Panchgram and
Sreekona shall be connected in co-ordination with SLDC, Assam.
7) Aizwal (PG) Sub-Station shall extend power to Kolasib (Mizoram) Sub-Station
through 132 kV S/C Aizwal - Kolasib line. Load at Kolasib shall be connected
in co-ordination with SLDC, Mizoram.
8) Kolasib Sub-Station shall extend power to Bairabi (Mizoram) Power Station for
survival/auxiliary power through 66 kV Kolasib – Bairabi line.
9) Badarpur Sub-Station shall extend power to Khliehriat (PG) Sub-Station
through 132 kV S/C Badarpur – Khliehriat line.
Page 52 of 74
10) Island F along with load at Panchgram, Sreekona & Kolasib shall be
synchronized with Island I at Khliehriat (PG) through any one of 132 kV D/C
Khliehriat – Khliehriat lines.
11) Island F and I along with load at Panchgram, Sreekona & Kolasib shall be
synchronized with Khandong at Khandong Power Station through any one of
132 kV D/C Khliehriat - Khandong lines. Khandong Power Station shall bring
and synchronize other machines.
12) Island F, I and Khandong along with load at Panchgram, Sreekona & Kolasib
shall be synchronized with Island G at Badarpur (PG) through 132 kV S/C
Badarpur – Jiribam line.
13) Khandong Power Station shall extend power to Kopili (NEEPCO) Power
Station through any one of 132 kV D/C Khandong – Kopili lines. Kopili shall
charge any one of 220 kV Bus(s) through 160 MVA ICT at Kopili Power
Station. Kopili Power Station shall bring machines and synchronize. Kopili
Power Station shall increase generation in co-ordination with NERLDC.
14) Kopili Power Station shall extend power to Misa (PG) Sub-Station through any
one of 220 T/C Kopili – Misa lines.
15) Misa Sub-Station shall extend power to Samaguri (Assam) Sub-Station through
any one of 220 kV D/C Misa – Samaguri lines. Load at Samaguri shall be
connected in co-ordination with SLDC, Assam. Bus Reactor (at Annx III) at
Samaguri Sub-Station shall be taken into service to contain voltage.
Note : SLDC, Tripura, Mizoram and Assam shall co-ordinate with
NERLDC before connecting loads to their systems.
Note : If Black start of units of this Island is not possible then start up power
shall be received from the following Islands :-
i. From Island G, Badarpur Sub-Station can receive power from Jiribam
(PG) Sub-Station through 132 kV S/C Badarpur – Jiribam line.
ii. From Island G, Aizawl (PG) Sub-Station can receive power from
Jiribam Sub-Station through 132 kV S/C Aizawl – Jiribam line.
iii. From Island I, Panchgram Sub-Station can receive power from
Lumsnong (Meghalaya) Sub-Station through 132 kV S/ Lumsnong –
Panchgram line.
Page 53 of 74
6.2.2 Restoration of Island G
This Island consists of Loktak, Manipur System, Jiribam, Pailapool, Imphal,
Dimapur, Doyang and Nagaland. The restoration procedure of this Island is
the same as adopted for Island E plus the following procedure:
1) Doyang Power Station shall black start any one of three machines & charge
132 kV Bus and extend power to Mokakchung Sub-Station. Otherwise they
should wait for extension of power from Dimapur (PG) Sub-Station.
2) Imphal (PG) Sub-Station shall extend power to Dimapur (PG) Sub-Station
through 132 S/C kV Imphal - Dimapur line. Any one of 220 bus(s) at
Dimapur Sub-Station shall be charged through any one of 2x100 MVA ICT at
Dimapur Sub-Station.
3) Dimapur (PG) Sub-Station shall extend power to Dimapur (Nagaland) Sub-
Station through any of 132 kV D/C Dimapur – Dimapur line. Load at
Dimapur (Nagaland) shall be connected in co-ordination with SLDC,
Nagaland.
4) Dimapur (PG) Sub-Station shall extend power to Kohima Sub-Station through
132 kV S/C Dimapur – Kohima line. Load at Kohima shall be connected in
co-ordination with SLDC, Nagaland.
5) Kohima Sub-Station shall extend power to Meluri Sub-Station through 132
kV S/C Kohima – Meluri line. Load at Meluri shall be connected in co-
ordination with SLDC, Nagaland.
6) Meluri Sub-Station shall extend power to Khiphire Sub-Station through 132
kV S/C Meluri – Khiphire line. Load at Khiphire shall be connected in co-
ordination with SLDC, Nagaland.
7) 66 kV Bus at Khiphire Sub-Station shall be charged through any one of 3X6.5
MVA ICT at Khiphire Sub-Station.
8) Khiphire Sub-Station shall extend power to Likhimro Power Station through
66 kV Khiphire – Likhimro line.
9) Dimapur (PG) Sub-Station shall extend power to Doyang (NEEPCO) Power
Station through any one of 132 kV D/C Dimapur – Doyang lines. Doyang
Power Station shall synchronize their generation in co-ordination with
NERLDC.
10) Doyang (NEEPCO) Power Station shall extend power to Mokokchung Sub-
Station through 132 kV S/C Doyang – Mokukchung line. Load at
Mokokchung shall be connected in co-ordination SLDC, Nagaland.
Page 54 of 74
11) This island shall be synchronized with Island F at Dimapur (PG) through any
one of 220 kV D/C Dimapur – Misa lines.
12) This island shall be synchronized with Island H at Dimapur (PG) through 132
kV S/C Mariani –Golaghat-Bokajan- Dimapur line.
Note : SLDC, Nagaland and Manipur shall co-ordinate with NERLDC before
connecting loads to their systems
Note : If black start of units of this Island is not possible then the start up power
can be received from the following Islands :-
i. From Island H, Dimapur (PG) Sub-Station can receive power form
Mariani Sub-Station through 132 kV S/C Mariani –Golaghat-Bokajan-
Dimapur line.
ii. From Island F, Jiribam Sub-Station can receive power from Badarpur
Sub-Station through 132 kV S/C Badarpur - Jiribam line.
iii. From Island F, Dimapur (PG) Sub-Station can also receive power
from Misa (PG) Sub-Station through any one of 220 kV D/C Misa -
Dimapur lines.
Page 55 of 74
6.2.3 Restoration of Island H
This Island consists of NTPS, LTPS, Mariani, Dibrugarh and Tinsukia. The
restoration procedure of this Island is same as that the restoration procedure
for Island B in addition to the following :-
1) LTPS shall extend power to Mariani (Assam) Sub-Station through 132 kV S/C
LTPS – Mariani line. Load at Mariani shall be connected in co-ordination with
SLDC, Assam. Any one of 220 kV Bus (s) at Mariani Sub-Station shall be
charged through any one of 2x100 MVA ICT at Mariani Sub-Station.
2) This island shall be synchronized with Island F at Mariani (Assam) through
220 kV S/C Samaguri - Mariani line. Bus Reactors (at annex III) at Mariani
Sub-Stations shall be taken into service to contain voltage.
Page 56 of 74
6.2.4. Restoration of Island I
This Island consists of Meghalaya System with Kahilipara and Sarusajai.
The restoration of this island is same as the restoration procedure of Island
C along with the following:
1) Umtru (Meghalaya) Power Station shall extend power to Sarusajai (Assam)
Sub-Station through any one of 132 kV D/C Umtru – Sarusajai lines. Load at
Sarusajai shall be connected in co-ordination with SLDC, Assam and
Meghalaya.
2) Umtru (Meghalaya) Power Station shall extend power to Kahilipara (Assam)
Sub-Station through any one of 132 kV D/C Umtru – Kahilipara lines. Load at
Kahilipara shall be connected in co-ordination with SLDC, Assam and
Meghalaya.
After synchronization of the above Islands (F, G, H and I) together at
Badarpur (PG), Khliehriat (PG), Dimapur (PG) and Mariani (Assam)
Sub-Stations, balance elements of the syatem shall be restored at the
earliest to build up total NER Grid. To contain voltage, charging of 400
kV lines and 220 kV lines shall be avoided initially as the Grid may not
absorb any jerk. NERLDC shall co-ordinate with all ISGS to maximize
their generation and SLDCs to maintain drawl from the Grid to avoid
any load generation mismatch. Restoration of rest of the Grid consisting
of Balipara, Khupi, Kimi, Gohpur, Nirjuli, Itanagar, SMS, Ranganadi,
Ziro, Daporijo, Along, North Lakhimpur , Dhemaji, Majuli, Rangia,
Rowta, Sipajhar, Depota, Barnagar, Nalbari, Dhaligaon, BTPS, AGBPP
and Deomali are as follow :
1) Mariani Sub-Station shall extend power to AGBPP (NEEPCO) through
400 kV S/C Mariani – AGBPP line (charged at 220 kV). AGBPP shall
synchronize units and extend power to Deomali Sub-Station through 220
kV S/C AGBPP – Deomali line. Load at Deomali shall be connected in
co-ordination with SLDC, Arunachal Pradesh.
2) Samaguri Sub-Station shall extend power to Balipara Sub-Station through
220 kV S/C Samaguri – Balipara line. Any one of 220 kV Bus(s) at
Page 57 of 74
Balipara Sub-Station shall be charged through any one of 2X50 MVA
ICT.
3) Balipara Sub-Station shall extend power to Khupi & Kimi through 132 kV
S/C Balipara – Khupi - Kimi. Load at Khupi and Kimi shall be connected
in co-ordination with SLDC, Arunachal Pradesh.
4) Balipara Sub-Station shall also extend power to Gohpur Sub-Station
through 132 kV S/C Balipara – Gohpur line. Load at Gohpur shall be
connected in co-ordination with SLDC, Assam.
5) Gohpur Sub-Station shall extend power to North Lakhimpur Sub-Station
through 132 kV S/C Gohpur – North Lakhimpur line. North Lakhimpur
Sub-Station shall extend power to Dhemaji & Majuli Sub-Stations through
132 kV S/C North Lakhimpur – Dhemaji & 132 kV North Lakhimpur -
Majuli lines respectively. Load at North Lakhimpur, Dhemaji & Majuli
shall be connected in co-ordination with SLDC, Assam.
6) Gohpur Sub-Stations shall extend power to Nirjuli (PG) Sub-Stations
through 132 kV S/C Gohpur – Nirjuli line. Nirjuli Sub-Station shall charge
33 kV Bus through any one of 1 × 10 MVA and 1×16 MVA ICT. Nirjuli
Sub-Station shall extend power to Itanagar Sub-Station through any one of
four nos. 33 kV lines. Load at Itanagar shall be connected in co-ordination
with SLDC, Arunachal Pradesh.
7) Nirjuli Sub-Station shall extend power to Ranganadi (NEEPCO) Power
Station through 132 kV S/C Nirjuli – SMS - Ranganadi line. Load at SMS
shall be connected in co-ordination with SLDC, Arunachal Pradesh.
8) Ranganadi Power Station shall extend power to Along (Arunachal) Sub-
Station through 132 kV S/C Ranganadi – Ziro – Daporijo – Along line.
Loads at Ziro, Daporijo and Along (Arunachal) shall be connected in co-
ordination with SLDC, Arunachal Pradesh.
9) Kahilipara Sub-Station shall extend power to Rangia and Sisugram
(Assam) Sub-Stations through 132 kV S/C Kahilipara – Rangia line and
132 kV S/C Kahilipara – Sisugram line respectively. Loads at Rangia and
Sisugram shall be connected in co-ordination with SLDC, Assam.
10) Rangia Sub-Station shall extend power to Rowta (Assam) and Depota Sub-
Stations through 132 kV S/C Rangia – Sipajhar - Rowta – Depota line.
Depota Sub-Station can also draw power from Balipara (PG) Sub-Station
Page 58 of 74
through 132 kV S/C Balipara – Depota line. Loads at Sipajhar, Rowta and
Depota shall be connected in co-ordination with SLDC, Assam.
11) Rangia Sub-Station shall extend power to Barnagar, Nalbari and
Dhaligaon (Assam) Sub-Stations through 132 kV S/C Rangia – Barnagar
line and 132 kV S/C Rangia – Nalbari - Dhaligaon line respectively.
Loads at Nalbari, Barnagar and Dhaligaon shall be connected in co-
ordination with SLDC, Assam.
12) Dhaligaon Sub-Station shall extend power to BTPS (Assam) Sub-Station
through any one of 132 kV D/C Dhaligaon – BTPS lines.
13) BTPS Sub-Station shall extend power to Salakati (PG) Sub-Station
through any one of 220 kV D/C BTPS – Salakati lines. Salakati Sub-
Station shall charge 132 kV Bus through any one of 2X50 MVA ICT.
Salakati Sub-Station shall extend power to Gelephu (Bhutan) through 132
kV Salakati – Gelephu Line (International Line). Load at Gelephu Again,
Gelephu can also receive power from Rangia (Assam) Sub-Station via
Motonga (Bhutan) Sub-Station through 132 kV S/C Rangia – Motonga
line.
14) Any one of 220 kV D/C Samaguri – Sarusajai lines shall be closed.
Sarusajai Sub-Station shall extend power to Agia and Boko Sub-Stations
through 220 kV Sarusajai – Boko - Agia line. Load at Agia and Boko shall
be connected in co-ordination with SLDC, Assam.
15) Agia Sub-Station shall extend power to BTPS Sub-Station through 220
kV BTPS – Agia line. Presently one circuit of 220 kV BTPS –Agia line is
available.
16) Balipara Sub-Station may charge one of 400 kV Bus(s) through 315 MVA
ICT. Tertiary Reactors (at Annex III) at Balipara Sub-Station shall be
taken into service to contain voltage. Balipara Sub-Station can charge any
one 400 kV D/C Balipara – Ranganadi lines if voltage permits. If required,
Bus Reactor at Balipara Sub-Station and Ranganadi Power Station may be
taken into service to contain voltage.
17) Misa (PG) Sub-Station shall charge 400 kV Bus through 315 MVA ICT.
Tertiary Reactors (at Anxx III) at Misa Sub-Station shall be taken into
service to contain voltage. Any one of 400 kV D/C Misa – Balipara lines
shall be closed. If required, Bus Reactor at Misa Sub-Station may be taken
into service to contain voltage.
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18) Misa Sub-Station shall extend power to Byrnihat (Meghalaya) Sub-Station
through any one of 220 kV D/C Misa – Byrnihat lines. 132 kV Bus at
Byrnihat Sub-Station shall be charged through any one of 2X160 MVA
ICT. Byrnihat Sub-Station shall extend power to EPIP II Sub-Station
through any one of 132 kV D/C Byrnihat – EPIP II lines. Load at EPIP II
shall be connected in co-ordination with SLDC, Meghalaya. EPIP II Sub-
Station shall extend power to EPIP I Sub-Station through any one of 132
kV D/C EPIP II – EPIP I lines. Load at EPIP I shall be connected in co-
ordination with SLDC, Meghalaya.
19) Ranganadi Power Station shall charge the 132 kV Bus through any one of
2 x 360 MVA ICT. Ranganadi Power Station shall synchronize machines,
if required.
20) Bongaigaon Sub-Station shall charge 400 kV Bus through 315 MVA ICT.
If required, Tertiary Reactors and Bus Reactor at Bongaigaon may be
taken into service.
21) Whenever ER power is available, NER Grid shall be synchronized with
ER Grid at Salakati through any one of 220 kV D/C Birpara – Salakati
lines. If synchronization with ER Grid through any line of 220 kV D/C
Birpara – Salakati lines delayed, NER Grid shall be synchronized with ER
Grid at Bongaigaon through any one of 400 kV D/C New Siliguri –
Bongaigaon lines.
Note : All SLDCs shall follow NERLDC’s real time advice
before connecting the loads. NERLDC shall closely
monitor the load-generation pattern of the Grid and
shall release the load stepwise base on the generation
availability.
Page 60 of 74
6.3 Restoration of 132 kV Network, after partial collapse, comprising of
Nagaland, Manipur, South Assam, Mizoram, Tripura and
Meghalaya
This system shall be restored as per the procedures adopted for the restoration of
Island C, Island D and Island E as well as the following procedure:
1) Misa (PG) Sub-Station shall extend power to Dimapur (PG) Sub-Station through
any one of 220 kV D/C Misa – Dimapur lines. 132 kV Bus at Dimapur Sub-
Station shall be charged through any one of 2X100 MVA ICT at Dimapur Sub-
Station.
2) Kopili (NEEPCO) Power Station shall charge 132 kV Bus through 160 MVA
ICT. Kopili Power Station shall extend power to Khandong (NEEPCO) Power
Station through any one of 132 kV D/C Kopili – Khandong lines. Khandong
Power Station shall bring machines and synchronize.
3) Khandong Power Station shall charge 33 kV Bus through any one of 1X16+1X7.5
MVA Transformers. Khandong Power Station shall extend power to Umrangshoo
Sub-Station through 33 kV S/C of Khandong – Umrangshoo line. Load at
Umrangsho shall be connected in co-ordination with SLDC, Assam.
4) Khandong (NEEPCO) Power Station shall extend power to Haflong (PG) and
Khliehriat (PG) Sub-Stations through 132 kV S/C Khandong – Haflong and any
one of 132 kV D/C Khandong - Khliehriat lines respectively.
5) Haflong (PG) Sub-Station shall extend power to Haflong (Assam) Sub-Station
through 132 kV S/C Haflong – Haflong line. Load at Haflong shall be connected
in co-ordination with SLDC, Assam.
6) Part of this system shall be synchronized with Island C at Khliehriat (PG)
through any one of 132 kV D/C Khliehriat – Khliehriat lines.
7) Khliehriat (PG) Sub-Station shall extend power to Badarpur (PG) Sub-Station
through 132 kV S/C Khliehriat – Badarpur line.
8) Badarpur (PG) Sub-Station shall extend power to Panchgram (Assam) & Kolasib
(Mizoram) Sub-Stations through 132 kV S/C Badarpur – Panchgram & 132 kV
Badarpur – Kolasib lines. Load at Panchgram (Assam) & Kolasib (Mizoram) shall
be connected in co-ordination with SLDC, Assam & Mizoram.
Page 61 of 74
9) Panchgram (Assam) Sub-Station shall extend power to Sreekona (Assam) Sub-
Station through 132 kV S/C Panchgram –Sreekona line. Load at Sreekona
(Assam) shall be connected in co-ordination with SLDC, Assam.
10) Part of this system shall be synchronized with Island D at Badarpur (PG) through
132 kV S/C Kumarghat – Badarpur line.
11) Dimapur (PG) Sub-Station shall extend power to Dimapur (Nagaland) Sub-
Station through any one of 132 kV D/C Dimapur – Dimapur line. Load at
Dimapur shall be connected in co-ordination with SLDC, Nagaland.
12) Dimpur (PG) Sub-Station shall extend power to Kohima Sub-Station through 132
kV S/C Dimapur – Kohima line. Load at Kohima shall be connected in co-
ordination with SLDC, Nagaland.
13) Kohima (Nagaland) Sub-Station shall extend power to Meluri Sub-Station
through 132 kV S/C Kohima – Meluri line. Load at Meluri shall be connected in
co-ordination with SLDC, Nagaland.
14) Meluri (Nagaland) Sub-Station shall extend power to Khiphire Sub-Station
through 132 kV S/C Meluri – Khiphire line. Load at Khiphire shall be connected
in co-ordination with SLDC, Nagaland.
15) 66 kV Bus at Khiphire Sub-Station shall be charged through any one of 3X6.5
MVA ICT at Khiphire.
16) Khiphire Sub-Station shall extend power to Likhimro through 66 kV Khiphire –
Likhimro line.
17) Dimapur (PG) Sub-Station shall extend power to Doyang (NEEPCO) Power
Station through any one of 132 kV D/C Dimapur – Doyang lines. Doyang Power
Station shall bring machines, if required and synchronize.
18) Doyang (NEEPCO) Power Station shall extend power to Mokokchung Sub-
Station through 132 kV S/C Doyang – Mokukchung line. Load at Mokokchung
shall be connected in co-ordination with SLDC, Nagaland.
19) This syatem shall be synchronized with Island E at Dimapur (PG) through 132
kV S/C Dimapur – Imphal line.
Note : SLDC, Nagaland, Manipur, Assam, Tripura, Mizoram and
Meghalaya shall co-ordinate with NERLDC, during the restoration
period, for connecting loads.
Page 62 of 74
6.4 Restoration of 132 kV Network after partial collapse comprising of
Nagaland System, Manipur System (except Jiribam) and Loktak :
Restoration of this system is as follows :-
1) Misa (PG) Sub-Station shall extend power to Dimapur (PG) Sub-Station through
any one of 220 kV D/C Misa – Dimapur lines. 132 kV Bus at Dimapur Sub-
Station shall be charged through any one of 2X100 MVA ICT at Dimapur Sub-
Station.
2) Dimapur (PG) Sub-Station shall extend power to Dimapur (Nagaland) Sub-
Station through 132 kV S/C Dimapur – Dimapur line.
3) Dimapur (PG) Sub-Station shall extend power to Dimapur (Nagaland) Sub-
Station through any one of 132 kV D/C Dimapur – Dimapur line. Load at
Dimapur shall be connected in co-ordination with SLDC, Nagaland.
4) Dimpur (PG) Sub-Station shall extend power to Kohima Sub-Station through 132
kV S/C Dimapur – Kohima line. Load at Kohima shall be connected in co-
ordination with SLDC, Nagaland.
5) Kohima (Nagaland) Sub-Station shall extend power to Meluri Sub-Station
through 132 kV S/C Kohima – Meluri line. Load at Meluri shall be connected in
co-ordination with SLDC, Nagaland.
6) Meluri (Nagaland) Sub-Station shall extend power to Khiphire Sub-Station
through 132 kV S/C Meluri – Khiphire line. Load at Khiphire shall be connected
in co-ordination with SLDC, Nagaland.
7) 66 kV Bus at Khiphire Sub-Station shall be charged through any one of 3X6.5
MVA ICT at Khiphire.
8) Khiphire Sub-Station shall extend power to Likhimro through 66 kV Khiphire –
Likhimro line.
9) Dimapur (PG) Sub-Station shall extend power to Doyang (NEEPCO) Power
Station through any one of 132 kV D/C Dimapur – Doyang lines. Doyang Power
Station shall bring machines, if required and synchronize.
10) Doyang (NEEPCO) Power Station shall extend power to Mokokchung Sub-
Station through 132 kV S/C Doyang – Mokukchung line. Load at Mokokchung
shall be connected in co-ordination with SLDC, Nagaland.
11) Loktak (NHPC) Power Station shall black start and charge 132 kV Bus.
Page 63 of 74
12) Loktak Power Station shall extend power to Imphal (PG), Ningthoukong,
Rengpang Sub-Stations through 132 kV S/C Loktak – Imphal, 132 kV S/C Loktak
– Ninghthoukong and 132 kV S/C Loktak – Rengpang lines respectively. Load at
Ningthoukong and Rengpang shall be connected in co-ordination with SLDC,
Manipur. Loktak Power Station shall bring and synchronize other machines.
13) Imphal (PG) Sub-Station shall extend power to Imphal (Manipur) Sub-Station
through 132 kV S/C Imphal – Imphal line. Load at Imphal (Manipur) shall be
connected in co-ordination with SLDC, Manipur.
14) Imphal (Manipur) Sub-Station shall extend power to Karong and Yangangpokpi
Sub-Stations through 132 kV S/C Imphal – Karong and 132 kV S/C Imphal –
Yangangpokpi lines. Load at Karong and Yangangpokpi (Manipur) shall be
connected in co-ordination with SLDC, Manipur. 132 kV S/C Ningthoukong –
Imphal lines shall be closed.
15) This system shall be synchronized with Rest of NER Grid at Dimapur (PG)
through 132 kV S/C Dimapur – Imphal line.
Note : If black start of Loktak (NHPC) Power Station units delayed, then start up
power required for bringing Loktak machines shall be received from the
follwing sources :-
i. Dimapur (PG) Sub-Station shall extend power to Imphal (PG) Sub-Station
through 132 kV S/C Dimapur – Imphal line.
ii. Imphal (PG) Sub-Station shall extend power to Imphal (Manipur) Sub-
Station through 132 kV S/C Imphal – Imphal line.
iii. Imphal (PG) Sub-Station shall extend power to Loktak Power Station
through 132 kV S/C Imphal – Loktak line. Loktak shall synchronize their
machines after receiving start up power.
iv. Loktak Power Station shall extend power to Ningthoukong Sub-Station
through 132 kV S/C Loktak – Ningthoukong line.
Note: SLDC, Nagaland and Manipur shall co-ordinate with NERLDC,
during the restoration period, for connecting loads.
Page 64 of 74
CHAPTER 7
REPORTING PROCEDURES
7.1 Introduction
This chapter deals with reporting procedures in respect of Grid Incidents/Grid Disturbance in
the system to all Users/STU/CTU, NERPC Secretariat and NLDC/NERLDC/SLDC. The
reporting procedure shall be in accordance with the relevant CEA Regulations.
7.2 Objective
The objective of this chapter is to define the Grid Incidents/Grid Disturbance to be reported,
the reporting route to be followed and information to be supplied to ensure consistent
approach to the reporting of Grid Incidents/Grid Disturbance.
7.3 Scope
This chapter covers all Users, STU, CTU, NERPC Secretariat, NLDC, NERLDC and
SLDCs.
7.4 Responsibility
i) The NERLDC/SLDC shall be responsible for reporting Grid Incidents/Grid Disturbance to
the Users, SLDC/STU, CTU /NLDC/NERLDC/NERPC Secretariat as the case may be.
ii) All Users, STU, CTU and the SLDC shall be responsible for collection and reporting of
all necessary data to NLDC, NERLDC and NERPC Secretariat for reporting Grid
Incidents/Grid Disturbance analysis as the case may be.
7.4. Categorisation of Grid Incidents and Grid Disturbance based on severity of
trippings
The categorisation of Grid Iincidents and Grid Disturbances shall be as follows:-
7.4.1 Categorisation of Grid Incidents in increasing order of severity :-
Category GI-1 - Tripping of one or more power system elements of the Grid like a
Generator, Transmission Line, Transformer, Shunt Reactor, Series Capacitor and Static
VAR Compensator, which requires re-scheduling of Generation or Load, without total
loss of supply at a Sub-Station or loss of integrity of the Grid at 220 kV (132 kV in the
case of North-Eastern Region)
Page 65 of 74
Category GI-2 - Tripping of one or more power system elements of the Grid like a
Generator, Transmission Line, Transformer, Shunt Reactor, Series Capacitor and Static
VAR Compensator, which requires re-scheduling of Generation or Load, without total
loss of supply at a sub-station or loss of integrity of the Grid at 400 kV and above (220
kV and above in the case of North-Eastern Region).
7.4.2 Categorisation of Grid Disturbance in increasing order of severity :-
Category GD-1 - When less than ten per cent. of the antecedent Generation or load in a
Regional Grid is lost;
Category GD-2 - When ten per cent. to less than twenty percent of the antecedent
Generation or Load in a Regional Grid is lost.
Category GD-3 - When twenty per cent. to less than thirty per cent. of the antecedent
Generation or Load in a Regional Grid is lost;
Category GD-4 - When thirty per cent. to less than forty per cent. of the antecedent
Generation or Load in a Regional Grid is lost ;
Category GD-5 - When forty per cent. or more of the antecedent Generation or Load in
a Regional Grid is lost.
Explanation: For the purpose of categorisation of Grid Disturbances, percentage loss of
Generation or Load, which ever is higher shall be considered.
7.5 Reporting of Grid Disturbance
7.5.1 Any of the following Grid Incidents/ Grid Disturbance require for
reporting by NERLDC/Users, SLDC, STU, CTU :-
i) System Islanding/System Split
ii) Regional Black Out/Partial System Black Out
7.5.2 Written reporting of Grid Incidents/Grid Disturbance by Users, STU,
CTU and SLDC to NERLDC : -
In the case of a Grid Incident/Grid Disturbance which was initially reported
by a User, STU, CTU or SLDC to NERLDC orally, the User, STU, CTU,
SLDC will give a written report to NERLDC in accordance with this chapter.
NERLDC in turn give a report to NLDC.
Page 66 of 74
7.5.3 Written Reporting of Events by NERLDC to Users, STU, CTU and
SLDC :-
In the case of an Grid Incident/Grid Disturbance which was initially reported
by NERLDC to Users, STU, CTU, SLDC, NLDC orally, the NERLDC will
give a written report to the Users, STU, CTU ,SLDC and NLDC in
accordance with this section.
7.5.4 NERLDC shall inform occurrence of the Grid disturbance to the constituents
immediately and to the NERPC at the earliest.
7.5.5 The Grid Disturbance resulting in failure of power supply to large areas in a
State shall also be reported by the NERLDC to CEA within twenty four hours
of the occurrence of the Grid Disturbance.
7.5.6 NERLDC shall also post on its website a brief Preliminary Grid Disturbance
Report, indicating the affected area or system, extent of outage and the likely
cause of initiation for the benefit of the constituents of the Region.
7.5.7 Form of Written Reports : -
A written report shall be sent to NLDC, NERLDC, a User, STU, CTU, SLDC,
as the case may be, in the reporting formats as devised by NERLDC and will
confirm the oral notification together with the following details of the event :-
i) Time and Date of Grid Incident/Grid Disturbance
ii) Location
iii Plant and/or Equipment directly involved
iv) Description and cause of incident/disturbance
v) Antecedent conditions of Load and Generation, including Frequency,
Voltage and the Flows in the affected area at the time of tripping including
Weather Condition prior to the Grid Iincident/Grid Disturbance
vi) Duration of interruption and Demand and/or Generation (in MW and
MWh) interrupted
vi) All Relevant system data including copies of records of all recording
instruments including Disturbance Recorder, Event Logger, DAS etc.
All operational data, including Disturbance Recorder and Event Logger
Reports, for analysing the Grid Incidents and Grid Disturbance and any
Page 67 of 74
other data which in its view can be of help for analysing Grid Incident or
Grid Disturbance shall be furnished by all the Entities within twenty four
hours to NERLDC and NERPC. No Entity shall block any
data/information required by NERLDC and NERRPC for maintaining
reliability and security of the Grid and for analysis of an event.
viii) Details of Relay Flags.
ix) Remedial measures.
7.6. Operational Data during Grid Incidents and Grid Disturbances
1.. NERLDC shall classify the Grid Incidents and Grid Disturbances according
to 7.4 of this procedure, analyse them and furnish periodic reports of Grid
Incidents and Grid Disturbances to NERPC which shall recommend
remedial measures to be taken on the Report of NERLDC to prevent
recurrences of such Grid Incidents and Grid Disturbances.
7.7. Operational Data Records
1. A record shall be kept of the number of Grid Incidents and Grid
Disturbances of various categories by the NERPC for each financial year.
2. A compendium of Grid Disturbances, indicating details such as the date and
time of the disturbance, the sequence of tripping, the cause, and the
Sequence of Restoration, remedial measures taken to avert recurrence of
such Incidents and Disturbances shall be maintained by NERPC.
Page 68 of 74
ANNEXURE - I
LIST OF POWER STATIONS WITH BLACK – START
FACILITIES ISGS : NEEPCO
START UP FACILITY
POWER
STATION
INSTALLED CAPACITY
(in MW)
UNIT TYPE SOURCE CAPACITY
(in kVA)
BLACK START
FACILITY
KHANDONG 2 X 25 HYDRO DG SET 1 X 250 YES
KHANDONG (KOPILI ST II) 25 HYDRO DG SET NA YES
KOPILI 4 X 50 HYDRO DG SET 1 X 600 YES
DOYANG 3 X 25 HYDRO DG SET 2 X 630 YES
RANGANADI 3 X 135 HYDRO DG SET 1 X 500 YES
AGTPP (R C NAGAR) 4 X 21 GAS DG SET 1 X 250 YES
AGBPP (KATHALGURI)
4 X 33.66+ 2 X 35+ 3 X 30
GAS + STEAM DG SET 1 X 950 + 1 X 250 NO
Page 69 of 74
ISGS : NHPC
STATE : ASSAM
START UP FACILITY
POWER
STATION
INSTALLED CAPACITY
(in MW)
UNIT TYPE SOURCE CAPACITY
(in kVA)
BLACK START
FACILITY
NAMRUP 3 X 23 + 12.5 + 30 + 22 GAS DG SET 844 YES
LAKWA 4 X 15 + 3 X 20 GAS NA NA YES #
ADAMTILA (IPP-DLF) 3 X 3 + 5 GAS GRID
POWER NA NO
BASKANDI 3 X 3.5 GAS GRID POWER NA NO
KARBI LANGPI 2 X 50 HYDRO DG SET 1 X 500 YES
# Black start facility is not functional presently
START UP FACILITY
POWER STATION
INSTALLED CAPACITY
(in MW)
UNIT TYPE SOURCE CAPACITY
(in kVA)
BLACK START
FACILITY
LOKTAK 3 X 35 HYDRO DG SET 2 X 315 + 1 X 700 YES
Page 70 of 74
STATE : MEGHALAYA
START UP FACILITY
POWER
STATION
INSTALLED CAPACITY
(in MW)
UNIT TYPE SOURCE CAPACITY
(in Volt)
BLACK START
FACILITY
UMIAM ST I 4 X 9 HYDRO BBaatttteerryy BBaannkk 5555 XX 22 YYEESS
UMIAM ST II 2 X 9 HYDRO BBaatttteerryy BBaannkk 5555 XX 22 YYEESS
UMIAM ST III 2 X 30 HYDRO BBaatttteerryy BBaannkk 5555 XX 22 YYEESS
UMIAM ST IV 2 X 30 HYDRO BBaatttteerryy BBaannkk 111100 XX 22..55 YYEESS
UMTRU 4 X 2.8 HYDRO BBaatttteerryy BBaannkk NN//AA YYEESS
STATE : TRIPURA
START UP FACILITY
POWER
STATION
INSTALLED CAPACITY
(in MW)
UNIT TYPE SOURCE CAPACITY
(in kVA)
BLACK START
FACILITY
GUMTI 3 X 5 HYDRO DG SET NA NO
BARAMURA 2 X 21 GAS DG SET 1 X 380 YES
ROKHIA 4 X 8 + 2 X 21 GAS DG SET 2 X 380 YES
Page 71 of 74
STATE : NAGALAND
START UP FACILITY
POWER
STATION
INSTALLED CAPACITY
(in MW)
UNIT TYPE SOURCE CAPACITY
(in kVA)
BLACK START
FACILITY
LIKIMRO 3 X 8 HYDRO DG SET NA NO
STATE : MIZORAM
START UP FACILITY
POWER
STATION
INSTALLED CAPACITY
(in MW)
UNIT TYPE SOURCE CAPACITY
(in kVA)
BLACK START
FACILITY
BAIRABI 4 X 5.7 HSD DG SET NA NO
Page 72 of 74
ANNEXURE – II
LIST OF SUB-STATION WITH SYNCHRONISING
FACILITIES CTU : POWERGRID
SUB-STATIONS
VOLTAGE LEVEL (in kV)
SYNCHRONISING
FACILITY
DG SET
DETAILS (in kVA)
BONGAIGAON 400 YES 1 X 250
SALAKATI 220 YES 2 X 200
BALIPARA 400 YES 2 X 250
MISA 400 YES 2 X 250
DIMAPUR 220 YES 1 X 250
IMPHAL 132 YES 1 X 100
JIRIBAM 132 YES 1 X 70
HALFLONG 132 YES 1 X 63
AIZWAL 132 YES 1 X 63
KUMARGHAT 132 YES (NOT OPERATIONAL) 1 X 63
BADARPUR 132 YES 1 X 100
KHLIEHRIAT 132 YES 1 X 100
NIRJULI 132 YES 1 X 100
ZIRO 132 YES 1 X 100
Page 73 of 74
STATE : ASSAM
SUB-STATIONS
VOLTAGE LEVEL (in kV)
SYNCHRONISING
FACILITY
DG – SET DETAILS (in kVA)
BTPS 220 YES NO
SARUSAJAI 220 YES NO
SAMAGURI 220 YES (NOT OPERATIONAL)
NO
MARIANI 220 YES NO
TINSUKIA 220 YES NO
KAHELIPARA 132 YES 1 X 30
DEPOTA 132 YES (NOT OPERATIONAL) NO
STATE : TRIPURA
SUB-STATIONS
VOLTAGE LEVEL (in kV)
SYNCHRONISING
FACILITY (YES / NO)
DG – SET DETAILS (in kVA)
79 TILLA (AGARTALA) 132 YES 1 X 30
Page 74 of 74
ANNEXURE – III
LIST OF SHUNT REACTORS IN NER
UTILITY LOCATION VOLTAGE
LEVEL (in kV)
NAME OF THE LINE/BUS
CAPACITY (MVAR) TYPE
POWERGRID MISA 33 33 kV BUS 4 X 25 TERTIARY
POWERGRID MISA 400 400 kV BUS 1 X 50 BUS
POWERGRID MISA 400 KATHALGURI 1 X 50 LINE
POWERGRID MISA 400 MARIANI 1 X 50 LINE
POWERGRID BALIPARA 33 33 kV BUS 4 X 25 TERTIARY
POWERGRID BALIPARA 400 400 kV BUS 1 X 50 BUS
POWERGRID BALIPARA 400 BONGAIGAON I 1 X 63 LINE
POWERGRID BALIPARA 400 BONGAIGAON II 1 X 63 LINE
POWERGRID BALIPARA 400 RANGANADI I 1 X 50 LINE
POWERGRID BALIPARA 400 RANGANADI II 1 X 50 LINE
POWERGRID BONGAIGAON 400 NEW SILIGURI I 1 X 63 LINE
POWERGRID BONGAIGAON 400 NEW SILIGURI II 1 X 63 LINE
POWERGRID BONGAIGAON 400 BALIPARA I 1 X 50 LINE
POWERGRID BONGAIGAON 400 BALIPARA II 1 X 50 LINE
POWERGRID BONGAIGAON 400 400 kV BUS 2 X 50 BUS
POWERGRID BONGAIGAON 33 33 kV BUS 2 X 25 TERTIARY
POWERGRID AIZWAL 132 132 kV BUS 1 X 20 BUS
POWERGRID KUMARGHAT 132 132 kV BUS 1 X 20 BUS
NEEPCO RANGANADI 400 BALIPARA I 1 X 50 LINE
NEEPCO RANGANADI 400 BALIPARA II 1 X 50 LINE
AEGCL MARIANI 220 220 kV BUS 2 X 12.5 BUS
AEGCL SAMAGURI 220 220 kV BUS 2 X 12.5 BUS
TSECL DHARMANAGAR 132 132 kV BUS 2 X 2 BUS
Total 1196