Transmission Distribution
Interface bottlenecks and
strategies for improved grid
Stability
By
Engr. A.S.A Bada
CEO (TCN)
GRID INTERFACE BOTTLENECKS
Major Causes include:
•
•
•
•
•
•
•
•
Radial state of network
Spatial network coverage
Transformer Capacity Constraints
Line Capacity Constraints
Switchgear Conditions
Grid indiscipline
Distribution network Conditions
Frequent trippings/Persistent faults
STATE OF NETWORK
• Radial State of network
– Steps Taken: NIPP presently constructing the
closing of the loop to Jos with a DC 330KV line
• Spatial Network Coverage
– Steps Taken: 26No. Lines and Substation projects
awarded in 2010 and 18No. Lines and Substation
projects to be awarded before the end of this year
(4 New substations to be constructed in the North
Eastern part and 5 New Substations in the NW )
Transformer Capacity Constraints
Steps Taken: On-going Capacity Strengthening Projects
Stations
Added Capacity
1
Birnin Kebbi 330KV
150MVA
2
Kumbotso 330KV
150MVA
3
Ayede 330KV
150MVA
4
Onitsha 330KV
150MVA
5
Afam 330KV
150MVA
6
Kantagora
60MVA
7
Sokoto
60MVA
8
Birnin Kebbi
60MVA
9
Funtua
60MVA
10
Katsina
60MVA
11
Onitsha
40MVA
ON-GOING CAPACITY STRENGTHENING
PROJECTS...............Ctd
12
13
14
15
16
17
18
19
20
21
22
Stations
Added Capacity
Akure
Ukpilla
Amukpe
Delta
Ajaokuta
New Haven
Akwanga
G.C.M.
Hadejia
Bauchi
Akangba
30MVA
30MVA
30MVA
60MVA
60MVA
60MVA
40MVA
15MVA
60MVA
60MVA
60MVA
ON-GOING CAPACITY STRENGTHENING
PROJECTS...............Ctd
• TCN expects delivery of Power
Transformers from 1st quarter of 2012
–4No. 300MVA 330/132KV Transformers
–5No. 150MVA 330/132KV Transformers
–10No. 100MVA 132/33KV Transformers
–10No. 60MVA 132/33KV Transformers
LINE CAPACITY CONSTRAINTS
Steps Taken:
• Gombe – Yola 330kV line has been energized
• 2nd Benin – Ajaokuta 330kV line has finally
been rehabilitated
• 3rd Benin –Onitsha DC 330kV line to be
commissioned soon
• Re-conductoring of weak and old lines (e.g
Aba – Itu, Itu – Calabar , Afam – PH, Delta –
Effurun, Ota - Papalanto) with higher thermal
capacity conductors are in various stages.
OUTCOME OF STRATEGY MEETINGS
#
Drop down Sub. By WBank
Source Line
1
330/132KV Substation at Ogijo
(Ikorodu)
Egbin – IkejaWest
330KV Line
2
330/132KV Substation at Epe
Omotosho – Aja Line
3
330/132KV Substation at New
Kano
Kaduna – Kano 330KV
line
4
132/33KV Substation at Choba PH
Omoku – PH Mains
Line
5
132/33KV Substation at
Awkunanu - Enugu
New Haven – Orji Line
6
132/33KV Substation at Kaltugo
Gombe – Yola Line
URGENT CONCERNS
•Too frequent 33KV
trippings
•Inadequate notification
of expansion projects
33KV TRIPPINGS FOR NOV. WK 1
#
DISTRIBUTION ZONES
ABUJA
2
BENIN
3
EKO
4
ENUGU
5
IBADAN
6
IKEJA
7
JOS
8
KADUNA
9
KANO
10 PH
11 YOLA
1
TOTAL NUMBER
OF TRIPPINGS
TOTAL ENERGY
Undelivered
(MWH)
126
125
55
208
191
43
71
107
46
121
63
1,628.95
4,674.39
4,405.25
15,261.96
4,305.78
3,289.8
1,385.12
758.74
558.04
4,201.89
533.66
MITIGATION STRATIGIES FROM
DISCO’s
• Submission of accurate data on customer
population and installed capacity (MVA)
• De-loading of 33KV Feeders through
network expansion
• Explore use of lattice towers for long 33KV
Lines
• Due to inadequate generation power
should be given to some feeders then
transferred to the others over time RATHER
THAN pro-lateral sharing of power on all
the feeders at the same time
MITIGATION STRATIGIES FROM
DISCO’s
• Adherence to operational instructions
• Gradual phase out of wooden cross
arms with fibre
• Movement of load on designated under
frequency relays should henceforth stop
• Disciplinary actions should be meted
out on erring staffs
MITIGATION STRATIGIES FROM
DISCO’s.......
• Supervising operators should
henceforth be alive to their
responsibilities
• Issuance of a circular from their
respective CEO’s demanding strict
adherence to operational
instructions
Further Key Transmission Grid Challenges
• Due to urbanization and environmental
issues, it is becoming increasing difficult
to acquire Right- Of-Way for new lines
• Increased power demand due to growth
in industries and population
• Vandalization of transmission lines
• Adverse Weather Conditions
• Poor power quality
• Transmission grid upgrades cannot keep
pace with power demand
STRATEGIES
-
-
-
Work is on-going on grid expansion.
Significant Investment is being made to effectively
double existing capacity through the NIPP
intervention
Line trace issues (mitigation against frequent line
trips) have been taken more seriously with focus on
contracting companies with requisite tools to work on
difficult terrains
Frequency stability has been largely achieved with
some units in Delta, Kainji and Egbin providing
frequency support in form of reserve margins
Deployment of FACTS facility at strategic node of the
network (e.g Kano, Gombe)
Work has commenced in deploying the Supergrid
network
330KV GRID STRUCTURE AFTER COMPLETION OF ALL ON-GOING
PROJECTS
REPUBLIC
OF
CHAD
2015 : new
Niamey
NIGER
SOKOTO
Sokoto
Katsina
132 kV
2015 : new
YOBE
Hadejia
JIGAWA
Birnin
Kebbi
BORNO
Gusau
KATSINA
ZAMFARA
Damaturu
Potiskum
2015 : new
Kano
KEBBI
Maiduguri
KANO
2010 : new
Zaria
REPUBLIC
OF BENIN
KADUNA
2015 : 2nd Circuit
2015 :
3rd Circuit
Bauchi
2
3
SHIRORO
NIGER
KAINJI
BAUCHI
Kaduna
Jos
Gombe
ADAMAWA
GOMBE
2
SAPELE
P/ST.
2
KWARA
2010: new
2015 : new
4
JEBBA/TS
Abuja
OYO
NASSARAWA
3
2
MAKURDI
Mambila
Akure
Aliade
ENUGU
EDO
Benin
Ikeja
2005 : new
Mambila Hydro
2
ONDO
2
Bali
BENUE
KOGI
Okitipupa
EGBIN
P/ST.
TARABA
2015 : new
AJAOKUTA
EKITI
2
NIGERIA
2015 : new
Geregu
ALAGBADO
Jalingo
Makurdi
Ado
Ekiti
OSUN
Abeokuta
Lafia
Lokoja
Osogbo
Ibadan
PLATEAU
Yola
ABUJA
IIorin
OGUN
REPUBLIC
OF CAMEROON
2
Minna
JEBBA/GS
2015 : new
Enugu
Akwa
EBONYI
Asaba
LAGOS
2
ONITSHA
4
Abakaliki
AN AMBRAAgip
SAPELE
P/ST.
IMO
CROSS
RIVER
Umuahia
ABIA
DELTA
POWER ST.
Owerri
DELTA
RIVERS
Uyo
Port
Harcourt
2
2
BAYELSA
Calabar
AKWA
IBOM
AFAM
POWER ST.
Some 330kV lines especially in
Lagos and Delta areas could not
be indicated on this geographical
Map.
See attached single diagram for
Details.
330KV LINES – MULTIPLE CIRCUITS
2
330KV LINES - EXISTING
330 KV
BULK SUPPLY POINT
H
HYDROELECTRIC POWER STATION
THERMAL POWER STATIONS
2015 : new
2015 : new
NOTE:
ATLANTIC OCEAN
TCN NETWORK WITH SUPERGRID
REPUBLIC
OF
CHAD
2015 : new
Niamey
NIGER
SOKOTO
Sokoto
Katsina
132 kV
2015 : new
YOBE
Hadejia
JIGAWA
Birnin
Kebbi
BORNO
TRANSMISSION GRID STRUCTURE WITH THE SUPER GRID IN PLACE
Gusau
KATSINA
ZAMFARA
Damaturu
Potiskum
2015 : new
Kano
KEBBI
Maiduguri
KANO
2010 : new
Zaria
REPUBLIC
OF BENIN
KADUNA
2015 : 2nd Circuit
2015 :
3rd Circuit
Bauchi
2
3
SHIRORO
NIGER
KAINJI
BAUCHI
Kaduna
Jos
Gombe
ADAMAWA
GOMBE
2
SAPELE
P/ST.
2
KWARA
2
Minna
2010: new
JEBBA/GS
2015 : new
4
JEBBA/TS
Abuja
OYO
NASSARAWA
3
2015 : new
EKITI
MAKURDI
Mambila
Aliade
Okitipupa
EGBIN
P/ST.
ENUGU
EDO
Benin
2015 : new
TRANSMISSION LINE LEGEND
Ikeja
2005 : new
Mambila Hydro
2
ONDO
2
Bali
BENUE
KOGI
Akure
2
ALAGBADO
REPUBLIC
OF CAMEROON
TARABA
Makurdi
AJAOKUTA
Geregu
Abeokuta
NIGERIA
2015 : new
Ado
Ekiti
OSUN
OGUN
Lafia
Lokoja
Osogbo
2
Yola
Jalingo
ABUJA
IIorin
Ibadan
PLATEAU
Enugu
Akwa
EBONYI
700KV LINES – SUPER GRID
Asaba
LAGOS
2
ONITSHA
4
Abakaliki
AN AMBRAAgip
SAPELE
P/ST.
IMO
700 / 330KV SUBSTATION
CROSS
RIVER
Umuahia
ABIA
DELTA
POWER ST.
Owerri
DELTA
RIVERS
Uyo
Port
Harcourt
2
2
BAYELSA
Calabar
AKWA
IBOM
AFAM
POWER ST.
330KV LINES – MULTIPLE CIRCUITS
330KV LINES - EXISTING
330 KV
BULK SUPPLY POINT
H
HYDROELECTRIC POWER STATION
THERMAL POWER STATIONS
2015 : new
2015 : new
NOTE:
Some 330kV lines especially in
Lagos and Delta areas could not
be indicated on this geographical
Map.
See attached single diagram for
Details.
2
ATLANTIC OCEAN
THANK YOU